Download Estuaries in the Balance - Center for Global Environmental Education

Estuaries in the Balance:
The Texas Coastal Bend
Teacher’s Guide
Developed by
Corey Mohan
John Shepard
Erica Cochrane
Joan Garland
© 2012 Hamline University’s Center for Global Environmental Education
All Rights Reserved.
Estuaries in the Balance
Page 2 of 103
TABLE OF CONTENTS
Table of Contents
Teacher’s Guide Overview............................................................................................................... 3
How To Use this Program................................................................................................................ 5
Technical Support: Frequently Asked Questions............................................................................ 6
Getting Started:
I. Google Earth Tour and Texas Coastal Bend Map…………………………..……….….. 7
II. Navigating the Program.................................................................................................... 8
III. Quick Guide to Program Videos, Interactives and TEKS………………..……………. 9
Program Segments:
Section 1: Estuary Introduction Video................................................................................. 11
Section 2: Blue Crabs in the Mix…………………………………………………..….….. 19
Section 3: Oyster Reef Builder............................................................................................. 26
Section 4: Redfish Angler..................................................................................................... 35
Section 5: A Whooper's Tale................................................................................................ 43
Section 6: Estuaries in the Balance Video............................................................................ 54
Glossary of Terms……………………………………………………………………………….… 63
Appendices
Appendix A: Texas Essential Knowledge and Skills Correlations (by grade)………………….… 70
Appendix B: Using Handheld Technologies in Field Experiences…………………...…………... 75
Appendix C: Printable Texas Coastal Bend Map and Student Mapping Exercise……………….. 79
Appendix D: Printable Pre- and Post-Test - in sections by Video and Sub-Module Content......... 81
Appendix E: Studio Scripts for Six Program Videos…………………………………………....... 88
Appendix F: Molt Mania Studio Script for Species and Habitats with Vocabulary………….…... 97
TABLE OF CONTENTS
Page 3 of 103
Estuaries in the Balance
TEACHER’S GUIDE OVERVIEW
Teacher's Guide Overview
Welcome to the Estuaries in the Balance: The Texas Coastal Bend! This program is a rich,
interactive multimedia tool that will enhance science and social studies investigations for
students in grades 4–8. Estuaries in the Balance: The Texas Coastal Bend explores essential
concepts about how healthy estuaries function. To accomplish this, the program uses key
indicator species and embeds them in five highly interactive experiences in four different
estuary systems. Short videos provide context for activities that challenge and engage students
as they build understanding about the complex and fascinating estuary ecosystem.
The program also brings to life the region’s environmental history and explores the relationship
between human activities and Coastal Bend estuaries. Students will understand connections between
land and water, upstream and downstream, and human and natural communities. The content and
activities encourage critical thinking about the value of the ecological services that estuaries provide
as well as the individual and societal behaviors that threaten estuary health as well as those that may
save them—truly, Estuaries in the Balance.
Flexible Modular Design
The modular design of Estuaries in the Balance: The Texas Coastal Bend enables the program to be
used in multiple ways. This learning resource is flexible and adapts to a variety of needs and
teaching styles. Though the content is non-linear and can be accessed and explored in any order, we
do recommend a general progression through the content for those who plan to use the program in its
BACK TO TABLE OF CONTENTS
TEACHER’S GUIDE OVERVIEW
Page 4 of 103
Estuaries in the Balance
TEACHER’S GUIDE OVERVIEW
entirety. See “Getting Started II: Navigating the Program” for ideas on how to navigate through
the program.
Grade Levels
Activities in this curriculum are appropriate for students in grades 4 – 8.
A Pre/Post Test
A printable pre- and post–test is included for you to test students’ prior knowledge and assess what
they have learned by using the program.
Texas Essential Knowledge and Skills–TEKS Correlations
All segments of the program have been correlated with Texas education standards (TEKS). You will
find live links to relevant standards in “Getting Started III: Quick Guide to Program Videos,
Interactives and TEKS” and again in each Video and Sub-module Lesson Plan. Texas correlations
found in Appendix A.
BACK TO TABLE OF CONTENTS
TEACHER’S GUIDE OVERVIEW
Page 5 of 103
Estuaries in the Balance
HOW TO USE THIS PROGRAM
How to Use This Program
Here are some ways teachers have used Estuaries in the Balance: The Texas Coastal Bend in the
classroom:
• Teacher presentation tool: Use the program as a presentation tool, projecting the content to
the class using a SmartBoard, computer projector, screen, and audio speakers. Engage
students in a discussion of the content and issues raised in the short introductory videos and
continue to the interactives either as a class or individually
• Student computer lab resource: All students can use the program at once in the computer lab.
• Student class project resource: Use the program as a resource for individual students in class
projects, or when other classroom work is completed.
• Pre-and post-field trip resource: Use the program to provide a context and to help interpret
hands-on learning during field trips that investigate community, school, family, and individual
connections with estuaries and watershed environments.
• Student exploration and presentation: Have small groups explore different sections of the
program and present those sections to the rest of the class using Estuaries in the Balance: The
Texas Coastal Bend as a presentation tool.
• Student use at home: Have students access the program at home via the Web.
Section Components
Live links to Texas Knowledge and Essential Skills correlations are included at the beginning of each
sub-module and video section in the Teacher Guide. The two stand-alone videos and each of the four
sub-modules have the following components to support your teaching:
• Synopsis: Brief description of the sub-module or video
• Big idea: The central concepts explored in the interactive module
• Learning objectives: What the students will learn in the sub-module; correlated to the pre- and
post-test found in Appendix D.
• Suggested sequence and keys to success: Suggestions for the teacher on how to prepare
yourself and your students to get the most from each video or sub-module
• Background information: A short introduction to the important ideas teachers need to
know in order to effectively teach the concepts in the module
• Pre/Post Video Discussion Questions: Discussion questions used at the start of each section
establish context, assess prior knowledge, guide students to important concepts, and help
students process and extend what they have learned.
• Video Viewing Guide: A printable series of questions students can complete as they view each
video—especially valuable to help students develop strategies for the program’s interactives.
• Vocabulary: Each module will define specific vocabulary words students need to know in order
to successfully investigate that section with links to the main glossary.
• Extension activities: Suggested activities that can help deepen students’ understanding of
concepts, and provide inquiry-based experiences that make use of the ideas in the submodules and videos.
BACK TO TABLE OF CONTENTS
HOW TO USE THIS PROGRAM
Page 6 of 103
Estuaries in the Balance
FREQUENTLY ASKED QUESTIONS
Technical Support: Frequently Asked Questions
Q. Should I use the High-Bandwidth or Low-Bandwidth Versions of the Program?
A. Estuaries in the Balance is designed to play over the Web on Macintosh and Windows computers,
on iPads, and on Android tablets. To accommodate the fact that the age of computer systems and
the speed of internet connections vary from school to school, high-bandwidth and low
bandwidth versions of the program are accessible from the program's landing page:
http://cgee.hamline.edu/CoastalBendEstuaries
If you're unsure which version is best for your computer or internet connection, start with
the high-bandwidth version. If, using the high-bandwidth version, the videos take too long to
load or play poorly, return to the landing page and choose the Low-bandwidth version.
Q. What browsers are supported?
A. In order for the program to play on computers and tablets, only relatively recent versions of today's
most common browsers are supported—specifically, the following:
•
•
•
•
•
Chrome
Firefox
Safari versions 5 & 6 (Macintosh only)
Internet Explorer versions 8 & 9 (Windows only)
Opera (Android tablets)
Q. What should I do if the program doesn't play well on my computer or tablet?
A. Here are several common symptoms and solutions if you're experiencing poor performance:
•
•
•
Symptoms: The program plays and you are using one of the supported browsers, but some
elements (such as videos) are slow to load and videos pause often or are choppy. Solution:
You may have a relatively slow Internet connection or old computer equipment and using the
Low-Bandwidth version of the program should improve performance.
Symptoms: Videos or other program elements don't load at all or won't play. Solution: It's
likely you are using an unsupported browser, and you should download a current version of
one of the supported browsers.
Symptoms: You're using a tablet and the entire program doesn't fit on the screen. Solution:
check your browser's preferences to hide or disable elements of your browser that take up
space at the top of the screen.
Q. Are there other sources of help?
A. Use the email feedback link on the landing page, or send a message to "[email protected]"
and one of our production team members will reply to your question.
BACK TO TABLE OF CONTENTS
FREQUENTLY ASKED QUESTIONS
Page 7 of 103
Estuaries in the Balance
COASTAL BEND MAP
Getting Started
Part I: Google Earth Tour and Texas Coastal Bend Map
Google Earth Estuary Tour
The Google Earth Estuary Tour link will download a Google Earth KMZ file. If Google Earth is
installed on your system, launch this file and a multi-stop tour of the Texas Coastal Bend will play
automatically. Link: http://cgee.hamline.edu/CoastalBendEstuaries/TX_Coastal_Bend_Tour.zip
Texas Coastal Bend Map
This map has the names of places and physical features included in the program. A printable page of
this map and a similar map for students to label are both found in Appendix C.
BACK TO TABLE OF CONTENTS
COASTAL BEND MAP
Page 8 of 103
Estuaries in the Balance
NAVIGATION FLOWCHART
Part II: Navigating the Program
Though navigation of the program is non-linear and its modular elements can be explored in any
order, we recommend the following sequence:
•
•
•
•
(1) Estuary Introduction Video and the (2)
Blue Crabs in the Mix Sub-module provide
the context and create a conceptual
foundation for the other modules.
(3) Oyster Reef Builder and (4) Redfish
Angler Sub-modules next.
(5) A Whooper's Tale Sub-module is the
most challenging interactive.
(6) Estuaries in the Balance Video serves as
the concluding video exploring human
changes to Texas Coastal Bend estuaries as
well as strategies to restore and sustain
estuary health.
(Back to Teacher's Guide Overview)
BACK TO TABLE OF CONTENTS
NAVIGATION FLOWCHART
Page 9 of 103
Estuaries in the Balance
VIDEOS, INTERACTIVES, & TEKS
Part III: Quick Guide to Program Videos, Interactives and TEKS
Estuary Introduction
Introductory Video (4 min. 45 sec.) includes:
• Estuary: defined–both generally and
characteristics of those in Texas
• Productivity: estuaries as spawning and
nursery grounds for many Gulf of Mexico fish
and shellfish species that humans consume
• Salinity: defined with images and examples–
general and Texas Coastal Bend specific
• Freshwater Inflow: defined with examples of
how four key indicator species adapt to
seasonal patterns
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
Blue Crabs In the Mix
This sub-module includes:
• Video: "Salinity and Blue Crabs" (5 min. 20
sec.). Explores the relationship between
salinity, blue crabs and life in the estuary
• A. Interactive: "In the Mix"–students explore
what happens when freshwater and salt water
mix San Antonio Bay
• B. Interactive: "Crab Molt Mania"–students
explore the question: "How does salinity
affect blue crabs and their habitats?"
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
Oyster Reef Builder
This sub-module includes:
• Video: "Oyster Video" (4 min. 51 sec.).
Explores oyster reef habitat and the lifecycle
of this fascinating indicator species of estuary
health. Students learn about efforts to rebuild
oyster reefs.
• Interactive: "Reef Builder Game"–students
help increase the oyster population of Copano
Bay by choosing the best reef-building
strategies and then using those strategies
where salinity is right for oysters.
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
BACK TO TABLE OF CONTENTS
VIDEOS, INTERACTIVES, & TEKS
Page 10 of 103
Estuaries in the Balance
VIDEOS, INTERACTIVES, & TEKS
Redfish Angler
This sub-module includes:
• Video: "Redfish Video" (5 min. 09 sec.)
Explores the redfish of Corpus Christi Bay
and how conservation efforts brought this
fishery back from near destruction.
• Interactive: ­ "Redfish Angler Game"
students explore the habitats of Corpus
Christi, Nueces and Redfish Bays while they
angle for redfish as precipitation and salinity
conditions change in the estuary.
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
A Whooper's Tale
This sub-module includes:
• Video: "A Whooper's Tale" (6 min. 20 sec.).
Tells the fascinating tale of a conservation
success story that is still unfolding. Explores
the Whooping Cranes’ life cycle as they make
annual visits to the Texas Coast.
• Interactive: ­ "Whooper Game"–students
learn to make good food choices for their
Whooper family in the Aransas National
Wildlife Refuge and what it takes to survive
as conditions change in the estuary.
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
Estuaries in the Balance
Concluding Video (7 min. 53 sec.) includes:
• Estuary Resources: how humans use estuary
resources in general and in the Texas Coastal
Bend.
• Ecological Services: the benefits that
estuaries provide human and natural
communities.
• Issues and Threats: for all estuaries and in
the Texas Coastal Bend region.
• Recovery and Sustainability: renewing
estuary ecosystems in general, throughout
Texas and along the Texas Coastal Bend.
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
(Back to Teacher's Guide Overview)
BACK TO TABLE OF CONTENTS
VIDEOS, INTERACTIVES, & TEKS
Page 11 of 103
Estuaries in the Balance
SECTION 1: ESTUARY INTRO VIDEO
Program Segments
Section 1: Estuary Introduction Video
Estuary Introduction
Introductory Video (4 min. 45 sec.) includes:
• Estuary: defined–both generally and
characteristics of those in Texas
• Productivity: estuaries as spawning and
nursery grounds for many Gulf of Mexico fish
and shellfish species that humans consume
• Salinity: defined with images and examples–
general and Texas Coastal Bend specific
• Freshwater Inflow: defined with examples of
how four key indicator species adapt to
seasonal patterns
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
Synopsis
"What is an estuary?" "Why are estuaries important?" These questions are explored through images
and examples that are relevant in a general sense and for Texas students in particular. Salinity, or the
amount of salt in a given volume of water, is defined, as are the factors that influence variations of
estuary salinity across Texas and throughout the year. Students consider the significance of how
estuarine species have adapted to an environment where fresh water mixes with salt water in a
constantly changing scenario. Scientists along the Texas Coastal Bend monitor many species of
plants and animals that inhabit estuary waters to better understand how estuaries function. Students
are introduced to the Eastern Blue Crab, the Whooping Crane, the Eastern Oyster, and the
Redfish—key indicator species of the health status of Texas Coastal Bend estuaries, which are
considered in peril. Students are challenged to reflect on the vital connection between human and the
natural communities of the Texas Coastal Bend.
Big Idea
Estuaries are vital ecosystems. Their health and well-being is inter-connected to and inseparable from
that of human communities. Understanding, valuing, and protecting these ecosystems are essential for
sustaining human and natural communities.
Learning Objectives
Students will demonstrate an understanding of:
1. the definition of an estuary by accurately identifying two key characteristics of an estuary,
how estuaries function as part of a larger Gulf of Mexico ecosystem, and by accurately
identifying two key functions estuaries provide for fish and shellfish.
2. how salinity values vary throughout the estuary by correctly ordering three categories of
water in a sequence from freshest to most salty. Those categories are freshwater, brackish
water and ocean water.
BACK TO TABLE OF CONTENTS
SECTION 1: ESTUARY INTRO VIDEO
Page 12 of 103
Estuaries in the Balance
SECTION 1: ESTUARY INTRO VIDEO
3. how salinity values vary throughout the estuary by accurately identifying four natural factors
that affect estuary salinity.
4. how human activities affect salinity by accurately identifying which factor is most affected by
human water use upstream
5. how climate differences affect estuaries by accurately describing the relationship between
rainfall and freshwater inflow to estuaries along the Texas Coast.
6. how human activities affect Texas Coastal Bend estuaries by accurately describing why Texas
Coastal Bend estuaries are vulnerable to the effects of human water use.
7. the relationship between freshwater inflow and estuary health by accurately identifying two
negative consequences of low freshwater inflow to the estuary.
8. how estuarine species adapt to their environment by identifying four estuarine species and
identifying how the blue crab moves throughout the estuary during its lifecycle responding to
changing salinity.
Suggested Sequence and Keys to Success
Before Class
1. Prepare for your class by reading the background information (below) and visiting live links
to other resources, which can be found just below the background information. Reviewing
vocabulary and the Estuary Introduction video script can help prepare you as well.
2. Review the video by clicking the Estuary Introduction button in the lower-left corner of the
home screen.
During Class
1. Use discussion questions (below) to prepare students to watch the Salinity and Crabs video.
The questions will help students find the content and conceptual connections in the video
that they need to be successful in the Interactives in the Modules to come.
2. Have students watch the video together. Follow the video with a review of the guiding
questions and a discussion.
Background information
Estuaries are places where freshwater meets and mixes with salt water. Along the Texas Coastal
Bend, that freshwater often comes from rivers and streams fed by watersheds that may extend far
inland. An estuary begins where freshwater from one or more rivers flows into a bay. These bays
may connect to other bays and lagoons closer to the Gulf of Mexico. Saltier Gulf water flows into
and out of those bays, moved by wind and tides.
Estuaries are distinguished from non-estuarine bays by being protected from the open ocean by
peninsulas and islands. Along the Texas Coastal Bend, barrier islands, like Mustang Island near
Corpus Christi, have inlets from the Gulf of Mexico. The islands create a more sheltered
environment that is a nursery and spawning ground for many ocean species and much of the
seafood people eat. The combined salt and fresh water in estuaries is sometimes called brackish
water. Here, plant and animals have adapted over time to these constantly changing conditions.
An estuary may be considered an ecosystem, with complex interactions between plant and animal life
that form patterns such as food webs and exchanges of energy that can be described as energy
pyramids. When you observe the Coastal Bend map, you see that Texas Coastal Bend estuaries vary
BACK TO TABLE OF CONTENTS
SECTION 1: ESTUARY INTRO VIDEO
Page 13 of 103
Estuaries in the Balance
SECTION 1: ESTUARY INTRO VIDEO
in their shapes and in the number and sizes of the rivers that flow into their bays. Estuaries have
changing levels of salinity, or saltiness, of the water, throughout the year. Salinity is influenced by a
several factors including, tides, wind, land formations, evaporation, and the amount of freshwater
that enters the estuary. Texas estuaries can vary widely in salinity, and that variation correlates
closely to climate, particularly the amount of precipitation that falls in the river basins that drain into
the estuary. In East Texas where rainfall averages more than 50 inches a year, estuaries have lower
salinity values while farther west and south salinity values tend to be higher. An extreme example of
high average salinity is the Laguna Madre estuary southwest of Corpus Christi, where a combination
of low rainfall, high rates of evaporation and very little freshwater inflow from rivers and streams
creates conditions where the salinity in the estuary is higher than the Gulf of Mexico, a condition
called hyper-saline.
Salinity is measured in parts per thousand or ppt for short. Average seawater has 35 grams of salt
per liter (1000 grams) of water, which is expressed as 35 ppt. The brackish water found in estuaries
typically varies from about 5ppt to 30 ppt. Freshwater is 0 ppt. Hyper-saline estuaries may have
water that reaches 40 and 50 ppt or even higher.
Estuary ecosystems provide many services besides food resources for human populations. They
protect coastlines from storms and erosion, filter out many pollutants, and provide nurseries for many
species of plants and animals.
Issues that have placed Coastal Bend estuaries at risk include habitat loss and water degradation due
to coastal development, pollution, dredging, rising sea levels, toxic spills and reduced freshwater
inflows from rivers and streams. Some species, like the Eastern Oyster, are no longer found in
Corpus Christi and adjoining bays in the numbers that those bays historically produced. High salinity
and pollution are factors in their decline. Other species that are seasonal residents, like the
endangered Whooping Crane, have fewer habitats due to coastal development and thus less food to
support historically much larger flocks. High salinity in estuary waters due to reduced freshwater
inflows is impacted by droughts and is also directly related to upstream use by a growing Texas
population. High salinity contributes to higher disease rates and parasites that attack Eastern Blue
Crabs. These crabs, like almost all estuary plants and creatures are osmoregulators. That means
they have adapted to age-old salinity patterns and can regulate their internal chemistry even in widely
varying salinities. However, when human water use upstream, combined with long droughts, raises
average salinity levels, it takes far more energy for estuarine species like the Eastern Blue Crab to
regulate their bodies. Those conditions put them at risk and increases rates of death and disease.
Habitat restoration, fish stocking, commercial and sport fishing regulation, reducing pollution, rebuilding oyster reefs, providing sanctuaries, and restoring more natural freshwater inflow to estuaries
are some among many strategies to halt further damage to Coastal Bend estuaries and help sustain the
vitality of these ecosystems. In addition, conserving water upstream and restoring more natural water
flows into those estuaries will be two of the greatest challenges facing Texas citizens in a near future
that predicts significantly increasing population growth and increasing water demands.
BACK TO TABLE OF CONTENTS
SECTION 1: ESTUARY INTRO VIDEO
Page 14 of 103
Estuaries in the Balance
SECTION 1: ESTUARY INTRO VIDEO
Pre/Post Video Discussion Questions
• What are some differences between ocean or Gulf of Mexico water and spring water or tap
water? How can you tell?
• What happens to water when a river reaches the coast and flows into a bay? What's in a river
besides water that may be carried all the way to the bay? Which elements carried in the river
benefit the estuaries and which ones may have harmful effects in the estuary?
• When you look at a map of the Texas Coastal Bend, what kinds of landforms do you observe?
What bodies of water can you identify? Do you notice any rivers or streams that contribute
freshwater from inland watersheds?
• What is "an estuary?" Has anyone here ever been in or near an estuary? Can anyone describe
what an estuary might look like, smell like, or sound like?
• (With a Venn diagram of two overlapping circles, one ocean and one river) What are some
characteristics of or animals and plants would you be likely to find in an ocean? What are
some characteristics of or plants and animals would you be likely to find in a river? Here,
where our two circles overlap is what you have described as an estuary. What are some
characteristics of or plants and animals would you be likely to find in an estuary?
• What kinds of resources does an estuary provide for people? How about for other animals and
plants? Are there any ways you can think of that estuaries help clean or protect coastal waters
and the environment?
• What part of the Texas coast has the most rainfall? The least? What do you think happens
when to estuary water when freshwater meets salt water in places where there is a lot of
rainfall and large rivers? How about where it is hot, dry and very little water reaches the
coast? Can anyone describe what the weather is like in a typical Texas year? For each
season? Can anyone describe how that might affect the mix of freshwater and salt water and
how that might change for each season during a typical Texas year?
• Besides changes in the amount of freshwater inflows, what else happens in an estuary that
might change salinity? What would you expect to happen to estuary water during and after a
hurricane? Why? What would happen within an estuary if storms moved enough sand and
debris to close a pass into the estuary from the Gulf of Mexico? What about if storms opened
up a new pass?
• Does human water use affect the amount of water that flows into an estuary? How?
• Has anyone ever caught a redfish, eaten an oyster or crab, or seen a whooping crane? Tell us
about that.
• Imagine a time before anyone lived here in Texas... and now think about Texas today. How
have Texans changed the Texas Coastal Bend over all those years? What do you think about
that? What changes have benefited people? What changes have benefited estuaries? What
changes have harmed people? What changes have harmed estuaries? Why do you think that?
• What does it mean for a plant or an animal to adapt to its environment? Can you think of a way
air-breathing whales adapt to living in the ocean? How do you adapt to the weather when you
find out it's raining outside? How about when it's really cold? Really hot?
BACK TO TABLE OF CONTENTS
SECTION 1: ESTUARY INTRO VIDEO
Page 15 of 103
Estuaries in the Balance
SECTION 1: ESTUARY INTRO VIDEO
Video Viewing Guide: “Estuaries Introduction” Video
As you watch the video, write your answers to these questions—you can pause the video or replay it
using the on-screen video controller.
1. Estuary creatures adapting to salinity is like?
2. What percentage of the Gulf of Mexico species enjoyed by people as seafood depend upon
estuaries?
3. What is the average salinity of seawater? What is the range of salinity found in a typical
estuary?
4. What is the most important factor that influences estuary salinity levels?
5. List three ways Texas estuaries along the northeast Gulf Coast are different than those in the
southwestern Gulf Coast.
6. How do the amounts of nutrients carried into estuaries change during the four seasons?
7. What is the average salinity range in waters surrounding oyster reefs?
8. Do Blue Crabs use only one or many areas in an estuary during their life cycles?
9. At what life stage are redfish found in estuaries?
10. Are whooping cranes seasonal visitors to estuaries or are they present year around?
BACK TO TABLE OF CONTENTS
SECTION 1: ESTUARY INTRO VIDEO
Page 16 of 103
Estuaries in the Balance
SECTION 1: ESTUARY INTRO VIDEO
Additional Resources
Coastal Bend Bays and Estuaries Program
The Coastal Bend Bays & Estuaries Program (CBBEP) is a local non-profit 501(c)(3)
organization dedicated to researching, restoring and protecting the bays and estuaries of the
Texas Coastal Bend. http://www.cbbep.org/aboutCBBEP.html
National Estuarine Research Reserve System
This content-rich site is student friendly and explores estuary ecosystems from an educator's
perspective. What is an estuary? Are all estuaries alike? How do we study estuaries? How do
estuaries impact my life? Basic information and more - http://estuaries.noaa.gov/
GulfBase.org
This page has active links to estuary monitoring stations throughout the Gulf coast. GulfBase is
a database of resources about the Gulf of Mexico. The goal of this website is to regroup,
synthesize, and make freely available Gulf of Mexico research information. The project’s
vision is that GulfBase will help researchers, policy makers, and the general public work
together to insure long-term sustainable use and conservation of the Gulf of Mexico.
http://www.gulfbase.org/bay/
Vocabulary
•
•
•
•
•
•
•
Bay(s) - A large, semi-enclosed body of water connected to an ocean through a tidal pass and
receiving fresh water from a river basin. A large bay may be called a gulf, a sea, a sound, or a
bight.
Blue Crabs (Eastern blue crabs) - A species of crab native to the waters of the western
Atlantic Ocean, the Pacific coast of Central America and the Gulf of Mexico. The blue crab is
an important part of the estuarine food web, and of significant seafood value and economic
importance in the United States.
Brackish - Salty to slightly salty water, resulting from a mixture of fresh and seawater, such
as that found in estuaries.
Climate - The statistics of temperature, humidity, atmospheric pressure, wind, precipitation,
atmospheric particle count and other meteorological elemental measurements in a given
region over long periods.
Drought(s) - An extended period of months or years when a region receives consistently
below average precipitation. It can have a substantial impact on the ecosystem and agriculture
of the affected region. Even a short, intense drought can cause significant damage and harm
the local economy.
Estuary(ies) - A partly enclosed coastal body of water with one or more rivers or streams
flowing into it, and with a free connection to the open sea. Estuaries are amongst the most
heavily populated areas throughout the world, with about 60% of the world’s population
living along estuaries and the coast. As a result, estuaries are suffering degradation by many
factors.
Evaporation - Liquid water becoming a gas.
BACK TO TABLE OF CONTENTS
SECTION 1: ESTUARY INTRO VIDEO
Page 17 of 103
Estuaries in the Balance
SECTION 1: ESTUARY INTRO VIDEO
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Fertilized - Fertilization is the fusion of gametes to produce a new organism. Depending on
the animal species, the process can occur within the body of the female in internal
fertilization, or outside (external fertilization). The entire process of development of new
individuals is called reproduction.
Freshwater (fresh water) - Naturally occurring water on the Earth's surface in ice sheets, ice
caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in
aquifers and underground streams. Fresh water is generally characterized by having low
concentrations of dissolved salts and other total dissolved solids.
Freshwater inflows (flows) - Freshwater generally refers to water, which collects within a
river basin and flows downstream from the inland sources. This water enters into the bay and
mixes with the more saline seawater, creating an estuary area that is less salty than the ocean.
Inlets - A narrow body of water leading inland from a larger body of water, often leading to
an enclosed body of water, such as a sound, bay, lagoon, or marsh. In seacoasts, an inlet
usually refers to the actual connection between a bay and the ocean.
Marsh(es) or coastal marsh(es) - A type of wetland that is dominated by herbaceous rather
than woody plant species. Marshes often form a transition between the aquatic and terrestrial
ecosystems, are important nursery areas and highly productive.
Nutrient(s) - A chemical that an organism needs to live and grow.
Organic material - Broken down remains of plants and animals in the environment.
Oyster(s) (Eastern Oyster(s)) - A group of bivalve mollusks, which live in marine or
brackish habitats. Humans commonly consume some kinds of oyster as a delicacy. Other
kinds are harvested for the pearl produced within the mantle.
Peninsula - A piece of land that is bordered by water on three sides but connected to
mainland.
ppt - Parts per thousand.
Redfish (or Red Drum) - An economically important game fish that is found in the Atlantic
Ocean from Massachusetts to Florida and in the Gulf of Mexico from Florida to Northern
Mexico.
Saline - Saline water is a general term for water that contains a significant concentration of
dissolved salts.
Salinity(ies) - The saltiness or dissolved salt concentration in water or within coastal soil.
Seawater (salt water) - Water originating from a sea or ocean.
Shellfish - A culinary and fisheries term for aquatic invertebrates used as food. Although
most kinds of shellfish are harvested from saltwater environments, some kinds are found only
in freshwater.
Spawning season - Spawning is the process of releasing the eggs and sperm. Spawning often
happens during a particular time of year during the annual season.
Tide(s) - The rise and fall of sea levels caused by the combined effects of the gravitational
forces exerted by the Moon and the Sun and the rotation of the Earth.
BACK TO TABLE OF CONTENTS
SECTION 1: ESTUARY INTRO VIDEO
Page 18 of 103
Estuaries in the Balance
SECTION 1: ESTUARY INTRO VIDEO
Extension Activities
1. Have students do an information search for "The Texas Coastal Bend." Groups could be
assigned one the four primary economic drivers: Transportation, Commercial Fishing, Oil and
Gas, and Recreation. Have students present what they'd learned to the class. Focus discussion
on how the economic sectors relate to each other, exploring how they might at times have
either compatible or conflicting interests and goals.
2. Divide a map of the Coastal Bend into areas, each assigned to a different group, and have
student groups create a map of their portion of the region on a larger-scale grid that could then
be displayed on the wall. Have them label geographic features by name and by type of
feature. Use this map as reference as students explore other aspects of the Coastal Bend.
3. Arrange a field trip for your students to experience the estuary firsthand through Texas
A&M’s Center for Coastal Studies or arrange a visit by the program’s traveling estuaries
trailer. http://ccs.tamucc.edu/aep/program.htm
4. Have an estuary expert visit your classroom from the University of Texas’ Marine Science
Institute, bringing hands-on activities for your students:
http://www.utmsi.utexas.edu/outreach.html
5. Using small groups, assign one of the four indicator species from the video to each group.
Two groups could share a single species. After groups complete an informational search, have
them present on their species to the class. Presentations could incorporate a variety of
Gardener’s "multiple intelligences"
http://en.wikipedia.org/wiki/Theory_of_multiple_intelligences
6. In four small groups, each assigned a season, have students explore how climate patterns
influence freshwater inflow to Coastal Bend estuaries and salinity of estuary water. Have
groups represent a Typical Texas year, a Very Dry Texas year, and a Very Wet Texas year for
their assigned season. Have them pick an "indicator species" that spends all or part of their
lifecycle in the estuary and describe how variable climate patterns may affect that species.
Have the group develop a report or presentation and share it with the rest of the class.
7. As a class, brainstorm human water needs and how human communities in Texas use water
resources. Look at the historical population and future predicted population trends for the
growth areas that are in the watersheds that feed Coastal Bend estuaries. Have students
brainstorm ways natural communities of plants and animals need and use water. Have
students identify conflicts between the needs of human and natural communities. Have the
students identify behavior changes and other solutions that would sustain both communities.
BACK TO TABLE OF CONTENTS
SECTION 1: ESTUARY INTRO VIDEO
Page 19 of 103
Estuaries in the Balance
SECTION 2: BLUE CRABS IN THE MIX
Section 2: Blue Crabs in the Mix
Blue Crabs In the Mix
This sub-module includes:
• Video: "Salinity and Blue Crabs"(5 min. 20
sec.). Explores the relationship between
salinity, blue crabs and life in the estuary
• A. Interactive: "In the Mix"–students explore
what happens when freshwater and salt water
mix San Antonio Bay
• B. Interactive: "Crab Molt Mania"–students
explore the question: "How does salinity
affect blue crabs and their habitats?"
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
Synopsis
This module focuses on the relationship between salinity and freshwater inflows in San Antonio
Bay, and how that relationship changes between typical conditions and more extreme variations in
Texas Coastal Bend climate patterns. In the first interactive, In the Mix, students manipulate
freshwater inflow levels to see the effects on salinity values in the estuary. In the second interactive,
Crab Molt Mania, students manipulate freshwater inflows to achieve good conditions for crabs during
different stages of their life-cycles, They also learn about how Eastern Blue Crabs— an indicator
species of estuary health—and other species live in key estuary habitats and salinity requirements of
common estuary organisms.
Big Idea
Plants and animals that live in the diverse habitats of an estuary have successfully adapted over time
to a mix of salt and fresh water. Freshwater inflows to the estuary lower salinity, or the concentration
of salt, in estuary water. Over the course of their life cycle, estuarine species have adapted over time
to changes in salinity based on natural, seasonal patterns of freshwater inflow.
Learning Objectives
Students will demonstrate an understanding of:
1. the relationship between estuary salinity and a key estuarine species by accurately applying the
concepts of freshwater inflow and estuary salinity in the Molt Mania interactive to
successfully support the lifecycle of a key indicator species, the Eastern Blue Crab.
2. the variation in estuarine habitats by accurately identifying four key habits found in Texas
Coastal Bend estuaries.
3. of the inter-dependence of estuarine species by accurately identifying three estuary species and
successfully categorize them as either producer, primary consumer or secondary consumer
4. how species adapt in an estuarine environment by accurately identifying an adaptation of a key
indicator estuarine species, the Eastern Blue Crab, that allows that species to find food in the
Oyster Reef habitat.
5. how scientists measure and describe salinity by accurately identifying and applying the terms
BACK TO TABLE OF CONTENTS
SECTION 2: BLUE CRABS IN THE MIX
Page 20 of 103
Estuaries in the Balance
SECTION 2: BLUE CRABS IN THE MIX
parts per thousand and ppt.
6. the relationship between salinity and estuarine species by successfully identifying one harmful
effect of high salinity to a key indicator species, the Eastern Blue Crab.
7. the lifecycle of an estuarine species by accurately identifying and ordering four lifecycle stages
of the Eastern Blue Crab.
8. how habitat supports estuarine species by accurately identifying two functions of habitat in the
estuary (food and protection) in the post-test and describe where and how one species finds
food and protection.
9. the relationship between salinity and estuarine species by accurately describe the relationship
between freshwater inflow and estuary salinity as well as how salinity affects a key estuarine
species, the Eastern Blue Crab, during its lifecycle
Suggested Sequence and Keys to Success
Before Class
1. Teachers may want to begin by reading the background information (below) and visiting live
links to other resources found just after the background information. Reviewing vocabulary
and the Blue Crabs In The Mix video script can help prepare you as well.
2. Explore the module on your own. Begin by clicking the Salinity and Blue Crabs button on the
main menu screen. After viewing the Salinity and Crabs video, try the In the Mix and Molt
Mania interactives.
3. Print and make copies of the Video Viewing Guide question sheet for each student.
During Class
1. Use the Discussion Questions (below) before having students watch the “Salinity and Crabs”
video. The questions will generate thinking about the sub-module’s themes.
2. Have students watch the video and complete the Video Viewing Guide questions. The latter
will help ensure that students understand key information needed to develop strategies for the
Interactives.
3. It's recommended to begin with the In the Mix Interactive before students play Molt Mania
4. Students are now ready to play the Interactives individually, in small groups or as a class. Each
interactive has a Help Screen that explains the game's goals and how to play.
In the Mix: Students change the amount of Freshwater Inflow that enters the estuary
for the four seasons. Have them activate all three pre-set scenarios on the Freshwater
Inflow control panel (labeled Very Dry Year, Typical Year, and Very Wet Year),
then have them manipulate the controls to see if they can achieve the highest estuary
salinity for the year (Teacher Hint - all controls set to Drought is the correct answer)
and the lowest (Teacher Hint - all controls set to Flood is the correct answer)
Molt Mania: Using what they have learned in the video and in In the Mix, students
manipulate the Freshwater Inflow to achieve the best salinity results for the Eastern
Blue Crabs of San Antonio Bay. When they achieve this, the Blue Crab lifecycle
icons will automatically move to estuary habitats. Have students click on each habitat
to learn more about that habitat and the plants and animals that live there. (Teacher
Hint - "Typical Year" settings used the first Interactive, In the Mix, is the correct
answer). Molt Mania Scripts and Vocabulary
BACK TO TABLE OF CONTENTS
SECTION 2: BLUE CRABS IN THE MIX
Page 21 of 103
Estuaries in the Balance
SECTION 2: BLUE CRABS IN THE MIX
Background information
Estuaries experience changing levels of salinity, or saltiness of the water, throughout the year.
Salinity is influenced by a several factors including, tides, wind, land formations, evaporation, and
the amount freshwater that enters the estuary. Texas estuaries vary widely in salinity and that
variation correlates closely to climate, particularly the amount of rain that falls in the river basins
that drain to the estuary. In East Texas where rainfall averages over 50 inches a year, estuaries tend
toward lower salinity values or lower concentration of salt in the water while farther west and south
salinity values are higher. An extreme example high average salinity is the Laguna Madre estuary
system southwest of Corpus Christi where a combination of low rainfall, high rates of evaporation
and very little freshwater inflow from rivers and streams creates conditions where the salinity in the
estuary is higher than the Gulf of Mexico. Estuaries like Laguna Madre, whose average salinities are
higher than the ocean are called hyper-saline.
The world's oceans are a "soup" of dissolved salts and other minerals. Water is an excellent solvent.
Over millions of years as water meets rocks and minerals in the oceans and on land, salts and other
minerals dissolve and are suspended in the water. Although the world's vast seas have variations,
they maintain a fairly consistent salinity, or the amount of salt in a given amount of liquid.
Salinity is measured in parts per thousand or ppt for short. For example, water from the Gulf of
Mexico has an average of 35 grams of salt for a liter (1000 grams) of water. Or, you could say the
salinity of water from the Gulf of Mexico averages 35
ppt. San Antonio Bay on the Texas Coastal Bend
receives much of its freshwater from the Guadalupe
River. The Guadalupe and San Antonio Rivers and
the basins drained by those rivers extend far up into
South Central Texas. When freshwater flows down
through these systems into the estuary that includes
San Antonio Bay, salinity levels drop in those bays.
Rain events in the estuary itself will also lower salinity
levels. Over the course of a typical year the salinity in
the estuary may vary from 5 ppt to 35ppt. As mentioned before, salinity levels in San Antonio Bay
are changed by many different factors but the amount of freshwater inflow from the Guadalupe River
is the most influential. This module explores the natural system and how that system works. It's
important to understand that human water use upstream that diverts water that would normally flow
into the estuary will affect salinity levels in the estuary especially in times of drought. With a
growing South Central Texas population, scientists, water planners, and increasingly, citizens
recognize that careful planning and changing our water-use behaviors are critical to maintaining
healthy estuaries.
It could be said that all the species of plants and animals that call estuaries home are either primarily
salt water or primarily fresh water organisms–but that they have adapted over time to an environment
that offers them a mixture of both. The scientific term is euryhaline which simply means they are
able to adapt to the wide range of salinities that estuaries offer. Most euryhaline organisms spend
their whole lives in environments like estuaries where salinity changes regularly. One species that
adapts well to the changes in estuary salinity is the Eastern Blue Crab. But this species has
experienced a drastic decline in recent times and along the Texas Coastal Bend. Scientists are looking
BACK TO TABLE OF CONTENTS
SECTION 2: BLUE CRABS IN THE MIX
Page 22 of 103
Estuaries in the Balance
SECTION 2: BLUE CRABS IN THE MIX
at rising salinity in estuary water as a factor. It's known that the crabs move throughout the estuary
during their lifecycle. They will begin as fertilized eggs released by females in high saline conditions
in the inlets between the Gulf of Mexico and the bays and may as mature adults, particularly males,
gather in freshwater at certain times in the Guadalupe delta. Scientists believe that the crabs respond
to cues they receive as salinity changes in the estuary telling them that it's time to move.
The estuary consists of many diverse habitats. This module focuses on four that are central to the
lifecycle of the Eastern Blue Crab–Open Water, Seagrass, Marsh and Oyster Reef. Producers,
primary consumers, and secondary consumers rely on these habitats to provide food and protection.
Rising salinity levels in Texas estuaries are a concern to scientists because prolonged high salinity is
harmful to many plants and animals including the Eastern Blue Crab who become more susceptible to
certain parasites and diseases.
Estuarine species can tolerate a wide range of salinity values in the course of a year but scientists are
concerned when the median, or middle value observed over the course of a year rises. This signals a
possible long-term trend toward higher average salinities. Scientists believe that rising salinity values
in the estuary due to drought, climate change and human water use upstream may be stressful to the
adaptations of estuarine species like the Eastern Blue Crabs - adaptations that usually enable them to
moderate the effects of certain range and duration of salinity levels. And if it's stressful to the Eastern
Blue Crabs, chances are many other organisms in the estuary are also at risk.
Pre/Post Video Discussion Questions
•
•
•
•
•
•
•
•
•
•
•
What makes the oceans salty? How much salt do you think is in the ocean?
Are there plants and animals that need salty water to survive? Why?
Are there plants and animals that need freshwater to survive? Why? What about humans?
Are there places along the Texas Gulf Coast that have a mixture of salt and fresh water?
Can you name any plants and animals that live there? Can you think of any adaptations that
allow them to live there?
Can you name a few ways that freshwater gets into the oceans or the Gulf of Mexico?
What is the weather like in a typical Texas year? Winter? Spring? Summer? Fall?
What do you think happens in the estuary as the seasons change in a typical Texas year?
What happens to the saltiness of estuary water as the seasons change?
What do you think would happen to the plants and animals that live there if you stopped the
freshwater from flowing in? What if you added lots of freshwater?
Where do the Blue Crabs that you sometimes see in restaurants come from? If you were a
crab in an estuary, where would you like to live and what would you eat? What might eat
you if you weren't careful?
Blue Crabs change or "metamorph" as they grow from eggs to adults. Where do you think
they go in the estuary and what do they need from their habitats to thrive? When they're tiny
larva? When they're adults?
If estuaries get too salty what do you think might happen to the plants and animals that live
there? What do you think might happen to Blue Crabs?
BACK TO TABLE OF CONTENTS
SECTION 2: BLUE CRABS IN THE MIX
Page 23 of 103
Estuaries in the Balance
SECTION 2: BLUE CRABS IN THE MIX
Video Viewing Guide: “Salinity & Crabs” Video
As you watch the video, write your answers to these questions—you can pause the video or replay it
using the on-screen video controller.
1. Estuary creatures have to adapt to extreme changes in salinity just as humans may experience
extreme changes in what?
2. What impacts on San Antonio Bay salinity are caused by spring and autumn rains that can
bring heavy freshwater flows from the Guadalupe River?
3. What impact on estuary salinity comes with dry summers and winters in South Central Texas?
4. In typical seawater, what percent is water and what percent is salt?
5. What does the abbreviation “ppt” stand for?
6. If, in a typical year, salinity in San Antonio Bay varies between 5ppt and 35ppt, what is the
range?
7. If the three buoys show median salinity values of 12ppt, 15ppt, and 28ppt, what is the overall
median value for the entire bay?
8. If you lived in Minnesota, would the median annual temperature be a good guide for how to
dress on any particular day?
9. Is it true or false that a drought year with a couple of strong rain storms could result in the
same range of salinity values in San Antonio Bay as would a typical year?
10. The video says that blue crabs don’t do well when salinity levels become too extreme. Do
you think the best salinity conditions would be Typical, Drought, or Flood?
BACK TO TABLE OF CONTENTS
SECTION 2: BLUE CRABS IN THE MIX
Page 24 of 103
Estuaries in the Balance
SECTION 2: BLUE CRABS IN THE MIX
Additional Resources
GulfBase.org
This GulfBase.org page is specific to San Antonio Bay. Basic facts about the bay and more http://www.gulfbase.org/bay/view.php?bid=sab
BlueCrabs.Info
Easy to follow site that defines with images and text the lifecycle of the blue crab.
http://www.bluecrab.info/lifecycle.html
Texas Park and Wildlife Department
Good overview of the Eastern Blue Crab and their home along the Texas coast.
http://www.tpwd.state.tx.us/huntwild/wild/species/bluecrab/
The Aransas Project
This environmental advocacy group's site has active models specific to the San Antonio Bay
system that demonstrate salinity variations under different freshwater inflow conditions.
http://thearansasproject.org/situation/coastal-ecosystems-and-fishing/
Vocabulary
•
•
•
•
•
•
•
•
Adapt(ed) - The process whereby an individual adjusts to changing conditions within its
habitat or a population, and becomes better suited to its habitat.
Adaptable - The ability for an individual or a population to become better suited to its
habitat.
Blue Crabs (Eastern blue crabs) - A species of crab native to the waters of the western
Atlantic Ocean, the Pacific coast of Central America and the Gulf of Mexico. The blue crab is
an important part of the estuarine food web, and of significant seafood value and economic
importance in the United States.
Buoy(s) - A floating device that can have many purposes, including aid to navigation and
marking fishing nets and crab traps. It can be anchored (stationary) or allowed to drift with the
sea wave.
Climate - The statistics of temperature, humidity, atmospheric pressure, wind, precipitation,
atmospheric particle count and other meteorological elemental measurements in a given
region over long periods.
Disease – An abnormal condition affecting the body of an organism. It may be caused by
external factors, such as infectious disease, or it may be caused by internal dysfunctions, such
as autoimmune diseases.
Drought(s) - An extended period of months or years when a region receives consistently
below average precipitation. It can have a substantial impact on the ecosystem and agriculture
of the affected region. Even a short, intense drought can cause significant damage and harm
the local economy.
Estuary(ies) – A partly enclosed coastal body of water with one or more rivers or streams
flowing into it, and with a free connection to open sea. Estuaries are amongst the most heavily
populated areas throughout the world, with about 60% of the world’s population living along
estuaries and the coast. As a result, estuaries are suffering degradation by many factors.
BACK TO TABLE OF CONTENTS
SECTION 2: BLUE CRABS IN THE MIX
Page 25 of 103
Estuaries in the Balance
SECTION 2: BLUE CRABS IN THE MIX
•
•
•
•
•
•
•
•
•
Freshwater (fresh water) - Naturally occurring water on the Earth's surface in ice sheets, ice
caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in
aquifers and underground streams. Fresh water is generally characterized by having low
concentrations of dissolved salts and other total dissolved solids.
Freshwater inflows (flows) - Freshwater generally refers to water, which collects within a
river basin and flows downstream from the inland sources. This water enters into the bay and
mixes with the more saline seawater, creating an estuary area that is less salty than the ocean.
Habitat(s) - An area that provides food, water and/or shelter for a particular species of
animal, plant, or other type of organism.
Median - The median of a finite list of numbers can be found by arranging all the
observations from lowest value to highest value and picking the middle one. If there is an
even number of observations, then there is no single middle value; the median is then usually
defined to be the mean of the two middle values.
Parasite(s) - An animal or plant that lives in or on, and obtains nourishment from, another
animal or plant.
ppt - Parts per thousand.
Range(s) - In a set of data, the range is the difference between the largest and smallest values.
Salinity(ies) - The saltiness or dissolved salt concentration in water or within coastal soil.
Seawater (salt water) - Water from a sea or ocean.
Extension Activities
1. Small Groups–Each group picks one of the four estuarine habitats in this module. Using the
content in Molt Mania and their own research, they create a project that will teach the other
groups about their habitat. Each group member could become an expert on a particular
species that lives in that habitat and describe its lifecycle and where it fits into the ecosystem
as producer, primary consumer or secondary consumer.
2. Students can create a wall of names and pictures of species displayed around the room and
divided into saltwater species, freshwater species and euryhaline species.
3. Students can duplicate the salinity of seawater and varying salinity values of estuary water–
from fresh or 0 ppt to ocean salinity of 35 ppt. They could also include models of hypersaline estuaries at 40 and 50 ppt. These could be created in one-liter containers and displayed
in the room.
4. Small Groups–Students could create a model of a specific Texas Coastal Bend estuary.
Students could observe how freshwater flows into the estuary after it is released upstream and
how freshwater mixes with "saltier" water in the bays and lagoons. They could identify four
or more habitats and the species that live there - or they could pick one species and show how
it moves through or in and out of different estuary habitats during its lifecycle.
5. Arrange a field trip for your students through Texas A&M’s Center for Coastal Studies to
experience the estuary firsthand. http://ccs.tamucc.edu/aep/program.htm
6. Have a estuary expert visit your classroom from the University of Texas’ Marine Science
Institute, bringing hands-on activities for your students:
http://www.utmsi.utexas.edu/outreach.html
7. Have students research the term "osmoregulation." Have them identify why and how both
humans and Eastern Blue Crabs share this adaptation. How does this help human and crabs
survive in their chosen habitats?
BACK TO TABLE OF CONTENTS
SECTION 2: BLUE CRABS IN THE MIX
Page 26 of 103
Estuaries in the Balance
SECTION 3: OYSTER REEF BUILDER
Section 3: Oyster Reef Builder
Oyster Reef Builder
This sub-module includes:
• Video: "Oyster Video" (4 min. 51 sec.).
Explores oyster reef habitat and the lifecycle
of this fascinating indicator species of estuary
health. Students learn about efforts to rebuild
oyster reefs.
• Interactive: "Reef Builder Game"–students
help increase the oyster population of Copano
Bay by choosing the best reef-building
strategies and then using those strategies
where salinity is right for oysters.
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
Synopsis
Students explore the estuarine world of oysters and oyster reef habitat in Copano Bay through a video
and interactive game. Understanding the oyster life cycle and what oysters need to thrive is essential
to reducing human behaviors that harm estuaries and oyster reefs. Valuing this creature and its
critical role in the estuary ecosystem is a foundation for changing behaviors to help sustain oysters
and oyster reef habitats. In the Interactive, students get to apply what they've learned about oysters,
salinity, and the requirements of good oyster reef habitat by trying their hand at re-building oyster
reefs, a real-life strategy that's being used, right now in Copano Bay.
Big Idea
Oysters and oyster reef habitats worldwide are being damaged and destroyed by human activity. Rebuilding oyster reefs, using recycled shells and other materials, is one strategy to reverse this trend.
Learning Objectives
Students will demonstrate an understanding of:
1. the Eastern Oyster lifecycle by accurately ordering the stages of their lifecycle: fertilized egg,
larva, pediveliger, spat, adult oyster.
2. the value of oyster reef habitat by accurately identifying a) a physical characteristic of reef
structure, b) another species that uses the habitat, and c) two categories of services oyster
reefs provide to other estuarine species–(food and protection).
3. the threats to oysters and oyster reef habitat by accurately identifying three reasons for their
decline.
4. what estuary conditions promote oyster and oyster reef productivity by accurately identifying 3
of the 5 optimal conditions for oyster productivity.
5. what estuary conditions promote oyster and oyster reef productivity by describing the
relationship between freshwater inflow, estuary salinity and the lifecycle of the oyster.
6. a human behavior that promotes oyster and oyster reef productivity by accurately identifying
two characteristics scientists mimic when re-building an oyster reef.
BACK TO TABLE OF CONTENTS
SECTION 3: OYSTER REEF BUILDER
Page 27 of 103
Estuaries in the Balance
SECTION 3: OYSTER REEF BUILDER
7. the economic benefits of oysters an oyster reefs by accurately identifying which sector of the
Texas Coastal Bend economy represents oyster harvesting.
8. the two key variables (salinity and oyster reef design) that promote oyster and oyster reef
productivity when re-building oyster reefs by successfully completing the Reef Builder Game.
9. how Texas Coastal Bend economic sectors (Gas and Oil, Transportation, Recreation and
Commercial Fishing) may have competing and conflicting interests in a group discussion
following the module.
Suggested Sequence and Keys to Success
Before Class
1. Teachers may want to begin by reading the background information (below) and visiting
live links to other resources found just after the background information. Reviewing
vocabulary and the Oyster Reef Builder video script can help prepare you as well.
2. Explore the module on your own. Begin by pressing the Oyster Reef Builder Crabs button
on the menu bar. The new screen will have the menu bar for this module. Watch the
Oyster Video and try the Reef Builder Game Interactive.
3. Print and make copies of the Video Viewing Guide question sheet for this module for each
student.
During Class
1. Use the Discussion Questions (below) to prepare students to watch the Oyster video. The
questions will help students find the content and conceptual connections in the video that
they need to be successful in the Interactive.
2. Have students watch the video and complete the Video Viewing Guide questions (below).
The latter will help ensure that students understand key information needed to develop
strategies for the Interactives.
3. Students are now ready to play the Reef Builder Game individually, in small groups or as
a class. The Interactive has a Help Screen that explains the game's goals and how to play.
Reef Builder Game - Students choose where to build oyster reefs in Copano Bay and
what kind of reef design to use. They will consider estuary salinity as they choose the
location among three options and the best reef building strategy. At the end of each
round they get feedback on their choices. (Teacher Hint–the best strategy is to build
all three reefs in Area I. That area has the lowest salinity and receives the most
freshwater inflow. The best strategy is the Multiple High Mounds, which best mimics
natural oyster reefs.)
Background information
Eastern Oysters found in Texas Coastal Bend estuaries are excellent indicators of estuary health
because they live their entire lives in one place. What is happening in the estuary is reflected in the
productivity of oyster reefs.
The measure of estuary health also extends throughout the estuary because oyster reefs also provide
critical habitat for a variety of estuarine species. Oysters are important to Texas and the Coastal
Bend for other reasons too. Oyster harvesting is a large part of the Coastal Bend economy.
BACK TO TABLE OF CONTENTS
SECTION 3: OYSTER REEF BUILDER
Page 28 of 103
Estuaries in the Balance
SECTION 3: OYSTER REEF BUILDER
Fisherman, restaurants, and wholesalers all contribute directly into the local economy. Texas is the
third largest producer of oysters in the country. Oysters filter and clean bay waters removing
plankton, sediments, heavy metals, bacteria and other wastes. Oyster reefs protect shorelines from
erosion.
Today, oyster reefs are one of the most threatened marine habitats on earth, with an estimated 15%
remaining worldwide. Within the Gulf of Mexico, an estimated 50 to 80 percent of native oyster
populations have been lost relative to historic levels. Declines in the abundance of oysters are a
consequence of habitat loss due to historical shell dredging, water quality degradation, disease, oil
spill effects, and hurricanes. In Galveston Bay, Texas, approximately 50%, or 32 km2 (8,000 acres)
of oysters were lost as a result of Hurricane Ike in 2008. The resulting sediment deposition
smothered live oysters, submerged available hard substrate, and inhibited larval oyster settlement
and natural recovery processes. In Louisiana, an estimated 50% of oysters were lost after the
Deepwater Horizon oil spill in response to freshwater that decreased salinity below oyster tolerance
levels. (Dr. Jennifer Pollack - Harte Research Institute)
To appreciate and value the creature it helps to understand as much as you can about them and their
amazing lifecycle.
Despite recent and historical losses, there is hope that restoration will increase populations in the Gulf
of Mexico. For successful and sustainable oyster reef restoration efforts, it is necessary to choose
sites that support long-term growth and survival of oysters. Those sites include areas where:
• oysters are already abundant
BACK TO TABLE OF CONTENTS
SECTION 3: OYSTER REEF BUILDER
Page 29 of 103
Estuaries in the Balance
SECTION 3: OYSTER REEF BUILDER
• disease is low
• lots of juveniles (spats) are found
• salinity is moderate
• temperature is moderate
• dissolved oxygen is high
Selection of suitable sites is an important first step in the restoration process as it can greatly
influence mortality factors and may largely determine the ultimate success of the restoration project.
Copano Bay is the southernmost bay on the Texas Coast that still has good conditions for oysters and
oyster reefs to thrive. Nueces Bay historically had productive oyster reefs but no longer can sustain
them. Decreases in freshwater inflows to Nueces and Corpus Christi Bays are responsible for salinity
levels that are too high for oysters. When salinity averages higher than 20ppt, then oysters are far
more prone to disease and parasites. When you travel further south along the Texas Coastal Bend
average salinities are too high for oysters due to the drier climate,
lower rainfalls, high rates of evaporation and low freshwater
inflows. As a result, efforts to build new reefs and extend existing
reefs are focused on Copano and adjoining bays.
Here’s how recycling works. Oysters are harvested and sold in
restaurants. Discarded shells are recycled from area restaurants,
dried in the sun to kill harmful bacteria and then stockpiled until
they are ready to be used. The oyster shells, which are sometimes
bagged, are loaded onto barges and towed to carefully chosen sites
where the shells are off-loaded. Why shells? Larval oysters hatch
from fertilized eggs and are free swimming in the water column. After two to three weeks the larval
oysters settle out of the water column and need a hard surface, referred to as a substrate, to cement
themselves, form a shell and grow. If larval oysters don't find a hard substrate on which to cement
themselves, they die. Recycled oyster shells placed in multiple high mounds mimic the natural reef
structure and provide an excellent surface that the larval oysters need.
BACK TO TABLE OF CONTENTS
SECTION 3: OYSTER REEF BUILDER
Page 30 of 103
Estuaries in the Balance
SECTION 3: OYSTER REEF BUILDER
Pre/Post Video Discussion Questions
• What can anyone tell me about the Eastern Oyster, a species that is found in many of the Texas
Coastal Bend bays? Has anyone in class ever seen an oyster up close? Has anyone ever eaten
an oyster? What was that like?
• What are some ways that oysters and oyster reefs help clean and protect water? Shorelines?
• Can anyone describe the lifecycle of an oyster?
• Oysters form oyster reefs. Has anyone ever seen an oyster reef? Can you describe it? Why do
oysters form reefs? What do reefs do for oysters? What do reefs provide for other species
that live in the estuary?
• What kind of other creatures might find the water in and around an oyster reef a good place to
live? Why? What can an oyster reef provide fish, crustaceans, mollusks and other creatures
that they need to survive?
• Oyster Reefs habitats are on the decline. In Texas only about 50 to 80 percent are left. Can
anyone give some reasons why they think oysters are in trouble?
• What do you think oysters need to survive and do well? We know that estuaries are a mix of
fresh and salt water. What kind of water conditions or salinity conditions do you think oysters
might prefer? Why?
• Nueces Bay used to have a healthy oyster reef habitat—enough for people to harvest and eat.
Now oysters and reefs are hard to find there. What do you think may have changed over the
last 100 years that could have caused that? How might people be part of the problem? How
could people be part of the solution?
• If you were to try and re-build an oyster reef how would you go about it? How would you
know where in the bay to build it? What would you build it with? Why? What shape would
you make it?
• Natural disasters like hurricanes can destroy oyster reefs by burying them with sediment.
Humans too have also been responsible for many changes to Texas estuaries that have been
harmful to oysters and oyster reefs. Can you think of how certain kinds of human activities
here on the Coastal Bend have changed our bays and the water in the bays? How do estuaries
and estuary water change when upstream communities use water that used to flow into the
bays? How would this affect oysters and oyster reefs?
• If all the oyster reefs disappeared in Texas bays, what other species of plants and animals might
suffer?
BACK TO TABLE OF CONTENTS
SECTION 3: OYSTER REEF BUILDER
Page 31 of 103
Estuaries in the Balance
SECTION 3: OYSTER REEF BUILDER
Video Viewing Guide: “Oyster Video”
As you watch the video, write your answers to these questions—you can pause the video or replay it
using the on-screen video controller.
1. Name three things about an oyster reef that make it good habitat for other creatures.
2. How is Texas ranked as a supplier of oysters in the U.S.?
3. What is the name given to the ancient piles of oyster shells left behind by the Copano Indians?
4. What percentage of oyster reefs survives worldwide? What about in Texas?
5. What are possible impacts when water use by people living in a watershed that drains to an
estuary significantly reduces freshwater inflows into the estuary?
6. Why is the health of an estuary’s oyster population a good indicator for the health of the
estuary ecosystem?
7. How many feet does a pediveliger have, and how does it attach to a reef?
8. What is a “spat”?
9. If you’re rebuilding an oyster reef, what reef shape should you use for the best results?
10. What general salinity levels are best for reefs to thrive?
BACK TO TABLE OF CONTENTS
SECTION 3: OYSTER REEF BUILDER
Page 32 of 103
Estuaries in the Balance
SECTION 3: OYSTER REEF BUILDER
Additional Resources
Harte Research Institute (HRI)
HRI is based at Texas A&M University, Corpus Christi TX. They are a leader in Oyster Reef
restoration and re-building efforts along the Texas Coastal Bend. This site tells about that
program. http://oysterrecycling.org/
Texas Park and Wildlife Department
One page with facts and information about the Eastern Oyster http://www.tpwd.state.tx.us/huntwild/wild/species/easternoyster/
Link to a student-friendly .pdf about the Eastern Oyster http://www.texasthestateofwater.org/screening/pdf.../eastern_oyster.pdf
GulfBase.org
Fact and information about Copano Bay - GulfBase is a database of resources about the Gulf of
Mexico. http://www.gulfbase.org/bay/view.php?bid=copano1
Vocabulary
•
•
•
•
•
•
•
•
Barge(s) - A flat-bottomed boat, built mainly for river and canal transport of heavy goods.
Barnacles - Related to crabs and lobsters. Barnacles are exclusively marine, and tend to live
in shallow and tidal waters. They are sessile (non-motile) suspension feeders, and have two
larval stages. Around 1,220 barnacle species are currently known.
Citizens - Citizenship denotes the link between a person and a state and is associated with the
right to work and live in a country and to participate in political life.
Disease - An abnormal condition affecting the body of an organism. It may be caused by
external factors, such as infectious disease, or it may be caused by internal dysfunctions, such
as autoimmune diseases.
Dredge(d)(ing) - Dredging is an excavation activity usually carried out at least partly
underwater with the purpose of gathering up bottom sediments and disposing of them at a
different location. This technique is often used to keep waterways navigable. Dredging is also
used as a technique for fishing for certain species of edible clams, oysters, and crabs.
Endangered - An endangered species is a population of organisms which is facing a high risk
of becoming extinct because it is either few in numbers, or threatened by changing
environmental or predation parameters.
Estuarine - Of or having to do with the area where the sea meets a freshwater stream/river.
An oyster is an estuarine animal.
Estuary(ies) - A partly enclosed coastal body of water with one or more rivers or streams
flowing into it, and with a free connection to the open sea. Estuaries are amongst the most
heavily populated areas throughout the world, with about 60% of the world’s population
living along estuaries and the coast. As a result, estuaries are suffering degradation by many
factors.
BACK TO TABLE OF CONTENTS
SECTION 3: OYSTER REEF BUILDER
Page 33 of 103
Estuaries in the Balance
SECTION 3: OYSTER REEF BUILDER
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Fertilized - Fertilization is the fusion of gametes to produce a new organism. Depending on
the animal species, the process can occur within the body of the female in internal
fertilization, or outside (external fertilization). The entire process of development of new
individuals is called reproduction.
Freshwater inflows (flows) - Freshwater generally refers to water, which collects within a
river basin and flows downstream from the inland sources. This water enters into the bay and
mixes with the more saline seawater, creating an estuary area that is less salty than the ocean.
Habitat destruction - The process in which natural habitat is rendered functionally unable to
support the species present. In this process, the organisms that previously used the site are
displaced or destroyed, reducing biodiversity.
Habitat(s) – An area that provides food, water and/or shelter for a particular species of
animal, plant, or other type of organism.
Larva(l) - A distinct juvenile form many animals undergo before metamorphosis into adults.
The larva's appearance is generally very different from the adult form. A larva often has
unique structures and organs that do not occur in the adult form. Larvae are frequently
adapted to environments separate from adults. Some species such as barnacles are immobile
as adults, and use their mobile larval form to distribute themselves.
Midden(s) – An old dump for domestic waste and other artifacts associated with past human
occupation.
Mussels - The common name used for members of several families of mollusks, from
saltwater and freshwater habitats. These groups have in common a shell whose outline is
elongated and asymmetrical compared with other edible clams, which are often more or less
rounded or oval.
Oyster reef(s) - Reefs formed by oysters.
Oyster(s) (Eastern Oyster(s)) – A group of bivalve mollusks, which live in marine or
brackish habitats. Humans commonly consume some kinds of oyster as a delicacy. Other
kinds are harvested for the pearl produced within the mantle.
Parasite(s) - An animal or plant that lives in or on, and obtains nourishment from, another
animal or plant.
Salinity - The measure of the salt concentration of water.
Plankton – Any organisms (animal, plant, bacteria, etc.) that drift in the water column and are
incapable of swimming against a current. They provide a crucial source of food to many large
aquatic organisms, such as fish and whales.
ppt - Parts per thousand.
Range(s) - In a set of data, the range is the difference between the largest and smallest values.
Redfish (or Red Drum) - An economically important game fish that is found in the Atlantic
Ocean from Massachusetts to Florida and in the Gulf of Mexico from Florida to Northern
Mexico.
Salinity(ies) - The saltiness or dissolved salt concentration in water or within coastal soil.
Spat - Attached oyster larvae are called spat. Spat are oysters less than 1 inch long.
Water quality - The chemical, physical and biological characteristics of water. The most
common standards used to assess water quality relate to health of ecosystems, safety of
human contact and drinking water.
Water recycling - Wastewater cleaned for re-use, usually for non-potable purposes such as
irrigating landscape and refilling aquifers.
BACK TO TABLE OF CONTENTS
SECTION 3: OYSTER REEF BUILDER
Page 34 of 103
Estuaries in the Balance
SECTION 3: OYSTER REEF BUILDER
Extension Activities
1. Arrange to visit an oyster fishing boat or processor or invite someone in the industry to your
classroom.
2. Have your class volunteer in a local oyster shell collection or reef-building project nearby.
3. Dissect oysters in the classroom. Have students identify the parts.
http://www.infovisual.info/02/009_en.html
4. Arrange a field trip for your students through Texas A&M’s Center for Coastal Studies to
experience the estuary firsthand. http://ccs.tamucc.edu/aep/program.htm
5. Have a estuary expert visit your classroom from the University of Texas’ Marine Science
Institute, bringing hands-on activities for your students:
http://www.utmsi.utexas.edu/outreach.html
6. Have students create a "storyboard" of illustrations depicting the lifecycle of an oyster.
7. Have small groups research one of the five major causes of the catastrophic decline of oysters
and oyster reefs: historical shell dredging, water quality degradation, disease, oil spill effects,
and hurricanes. Have groups present their research to the class. Have students brainstorm
about what could be done to reverse the trend. Have students research and propose what is
being done to bring back oyster populations for the specific problem that they were assigned.
8. Have small groups or individuals research a species that lives around or depends on oyster
reefs for food and protection. Create a mural of an oyster reef and have each group add their
species to the mural.
9. Have students pick an ancient culture or tribe that lived in Texas and depended on the oyster
for part of their diet. Copane and Karankawa are examples of two tribes that inhabited the
Coastal Bend.
BACK TO TABLE OF CONTENTS
SECTION 3: OYSTER REEF BUILDER
Estuaries in the Balance
Page 35 of 103
SECTION 4: REDFISH ANGLER
Section 4: Redfish Angler
Redfish Angler
This sub-module includes:
• Video: "Redfish Video" (5 min. 09 sec.)
Explores the redfish of Corpus Christi Bay
and how conservation efforts brought this
fishery back from near destruction.
• Interactive: ­ "Redfish Angler Game"
students explore the habitats of Corpus
Christi, Nueces and Redfish Bays while they
angle for redfish as precipitation and salinity
conditions change in the estuary.
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
Synopsis
Corpus Christi Bay and the adjoining bays and lagoons provide the setting for this sub-module, which
has a video and an interactive game. Within an "angling" scenario, students learn about the life cycle
of this highly valued estuarine-dependent species. Students explore the relationship between redfish
and two essential habitats—seagrass and oyster reefs. Content includes, salinity requirements of
redfish, variations in the bays, reasons for the sharp decline of the redfish along the Texas Coastal
Bend and strategies that have restored redfish populations. Students apply this knowledge as they
look for redfish throughout the bay system and try to catch redfish at the right place under the right
conditions.
Big Idea
Estuarine species such as redfish require healthy habitat and a tolerable range of salinity values to
thrive during the different stages of their lifecycle. They also need protection from human activities
that threaten them and their habitats.
Learning Objectives
Students will demonstrate an understanding of:
1. how estuary systems function by accurately identifying the Nueces River as the main source of
freshwater inflow for the Corpus Christi Bay system.
2. the geography of the Corpus Christi Bay system by accurately identifying Corpus Christi Bay,
Nueces River, Nueces Bay and Redfish Bay as components of that system.
3. the lifecycle stages of the redfish by accurately ordering four of the stages.
4. how redfish use different parts of the estuary at different stages of its lifecycle by accurately
matching the stages to the geography and habitats in the bay system.
5. the relationship between estuarine species, habitat and freshwater inflow by successfully
applying what they have learned about that relationship in the Redfish Angler interactive.
6. the threats to one estuarine species, the redfish, by accurately identifying two human activities
that historically decimated the redfish population.
7. strategies that protect and sustain the estuary and one estuarine species, the redfish, by
accurately identifying three of those strategies being utilized along the Texas Coastal Bend.
BACK TO TABLE OF CONTENTS
SECTION 4: REDFISH ANGLER
Estuaries in the Balance
Page 36 of 103
SECTION 4: REDFISH ANGLER
Suggested Sequence and Keys to Success
Before Class
1. Teachers may want to begin by reading the background information (below) and visiting
live links to other resources found just after the background information. Reviewing
vocabulary and the Redfish Angler video script can help prepare you as well.
2. Explore the module on your own. Begin by clicking the Redfish Angler button on the main
menu screen. The Redfish Angler menu screen appears with the links for this module.
Watch the Redfish Video and try the Redfish Angler Game interactive.
3. Print and make copies of the Video Viewing Guide question sheet for this module for each
student.
During Class
1. Use the Discussion Questions (below) before students watch the Redfish Video. The questions
will generate thinking about the sub-module’s themes.
2. Have students watch the video and complete the Video Viewing Guide questions. The latter
will help ensure that students understand key information needed to develop strategies for the
Interactives.
3. Students are now ready to play the Redfish Angler Game individually, in small groups or as a
class. The Interactive has a Help Screen that explains the game's goals and how to play.
1. Redfish Angler Game: Students angle for redfish in Corpus Christi and adjoining bays.
They can choose either a dry or wet year to begin. They apply what they have learned
about salinity and freshwater inflow and habitat during either a Wet or Dry year. It's
recommended that students watch the Salinity and Blue Crabs video and play the In the
Mix and Molt Mania interactives first, if they haven't done so. Students pick the Wet or
Dry Year, move their boat to one of the three Areas and press the pay button. A Feedback
Screen tells them how they did. (Teacher Hint - during a dry year, more fish can be found
"up estuary" in Habitat 1 near the Nueces River Delta. Redfish are following prey that
seeks out the fresher mix of estuary water near the Delta where the river freshens the bay.
During a wet year more fish can be found in Area 3, Redfish Bay, where good habitat and
the moderate salinities of a wet year make fish plentiful)
Background information
Redfish, also known as Red Drum, are an estuarine-dependent species because they spend part of
their life cycle in estuaries. They are one of the most popular sportfish found along the Texas Coastal
Bend, and because of that, they are considered a valuable part of the recreation economic sector.
Fishing boats, bait, gas, hotels, motels and restaurants are just a few of the business that benefit from
the visitors drawn to the area to fish for this species. They are prized for their speed, fight, and flavor
and attract sport fishermen from throughout Texas and the United States. Redfish can be found in U.S
coastal waters from Maine to Mexico. They belong to the drum family and are related to the Atlantic
croaker, spotted seatrout and black drum, other species also found in Coastal Bend waters. The most
distinguishing mark that identifies a Redfish is the single large black spot on the upper part of the
base of their tail. They can be a range of colors from silver to coppery red.
Redfish are primarily secondary and tertiary consumers of other estuarine species at different stages
during their lifecycle. Adult fish gather between August and December along the Gulf side of barrier
BACK TO TABLE OF CONTENTS
SECTION 4: REDFISH ANGLER
Estuaries in the Balance
Page 37 of 103
SECTION 4: REDFISH ANGLER
islands. Here they stay near-shore and by the inlets that connect the bays to the Gulf of Mexico.
Females can spawn more than a dozen times in a season and produce up to 200,000 eggs. Eggs are
released into the current where sperm from the males fertilizes them and the lifecycle begins. Once
eggs hatch, currents carry the larvae into the shallower, warmer water in the estuary. Here among
seagrasses, they find protection from predators and from the tidal currents, which might otherwise
carry them back out of the estuary. As secondary consumers, the larvae feed on small invertebrates
and zooplankton until they are about an inch long. Once they grow over an inch and until they reach
thirty inches, redfish are considered juveniles. Redfish can grow up to a foot long their first year and
almost double that by their second year. They prefer quieter protected waters of estuary bays where
as tertiary consumers they feed on small fish, shrimp and crabs. Redfish over 30 inches long or over
four years old are considered mature fish. Mature fish feed on larger fish, shrimp and crabs and as
adults, venture more into Gulf waters only occasionally spending time in the bays and shallower
water of the estuaries. Once mature, these redfish are ready to spawn and begin the lifecycle once
again.
Over-fishing nearly wiped out the native Redfish along the
Texas Coastal Bend. In the late 1980's in response to this
trend, new regulations ended commercial net fishing,
designated this species a game fish, and set size and catch
limits for fisherman. Texas began a robust fish-stocking
program to supplement the wild production and release
millions of young fish each year into Texas waters. The redfish
populations are now strong and good management combined
with re-stocking has been the key to that success.
Habitat destruction remains a concern. As of 2006, Texas has
new regulations that make it illegal to damage five species of Texas seagrass in the Redfish Bay State
Scientific Area. The regulations hold boat operators responsible for damage. The fifty square miles
within this area include about 14,000 acres of submerged seagrass. Motorboat propellers scar and
damage seagrass beds particularly when motors extend too low into the shallow water and when
boats are operated too fast. Redfish Bay, part of the Corpus Christi Bay system, is the northernmost
bay on the Texas coast that has large stands of seagrass—yet another reason to manage and protect
this popular fishing and critical redfish habitat.
Reduced freshwater inflow from the Nueces River into the delta and Nueces bay is responsible for
high salinity that has changed the ecosystem of the Corpus Christi Bay system. Human water use
upstream has diverted fresh water that used to flow into the estuary. Without that volume to freshen
the bays, productive oyster reefs that cannot tolerate extended high salinity have largely disappeared.
This means habitat has been lost that many other estuarine species depend on, including the Redfish.
Efforts are being made to correct past mistakes and make scientific determinations to establish the
amount and the timing of freshwater inflows that the Corpus Christi Bay system needs to sustain and
rebuild vital estuarine habitat. However, competition between human use and allowing more natural
flows into the estuary will continue to be an issue.
BACK TO TABLE OF CONTENTS
SECTION 4: REDFISH ANGLER
Estuaries in the Balance
Page 38 of 103
SECTION 4: REDFISH ANGLER
Pre/Post Video Discussion Questions
• What can anyone tell us about redfish or about fishing for redfish? Has anyone ever caught a
redfish? Seen one? Eaten one that you caught? Eaten one in a restaurant? They're also called
Red Drum. Does anyone know why? (Males use an air bladder that creates a "drumming
sound" during spawning season)
• When you or other people come to the coast to fish for redfish, how does that benefit the people
who live here? The four major sectors of the Texas Coastal Bend economy are Oil and Gas,
Recreation, Transportation, and Commercial Fishing. What category does sport fishing fall
into? Does anyone know why Texas ended commercial netting of Redfish? (See background
material above)
• Redfish are called "estuary dependent." Can anyone describe what he or she thinks that means?
What if some fish or other species spend much of their adult life outside of an estuary. Could
they still be "estuary dependent?" Why or why not?
• Redfish, unlike oysters, could swim throughout the estuary. What kinds of habitat do you think
they like? Why?
• Can anyone think what the stages of the Redfish lifecycle might be? What might be some
reasons redfish need to use different habitats at different stages of life?
• You know a lot about freshwater inflow and salinity (providing they have done the submodules in the suggested order). How do you think salinity affects redfish? How does
salinity affect those species the redfish eat? How do you think salinity affects a seagrass
bed...an oyster reef?
• If it was a very rainy year and salinity values were generally low, where would you go in the
estuary if you were a redfish? Why? How about a real dry year when salinity values were
pretty high?
• What are some ways habitats might be damaged in the shallow water of the bays that redfish
love? How else can habitats be damaged? What do you think might be the effects of high
salinity for a long time? How do human activities and ways people use water affect the
estuary?
• If redfish were in trouble and they were getting hard to find in the estuary, what could be some
things you could do to help them? What if you were able to make new laws and regulations?
Does everyone agree that those are good ideas? How could you balance the needs of the
natural community, like our redfish, with the needs of fisherman and people who like to eat
fish in a restaurant? How would you balance the freshwater needs of an estuary and all the
plants and animals that live there with the freshwater needs of people who live nearby or
upstream?
BACK TO TABLE OF CONTENTS
SECTION 4: REDFISH ANGLER
Page 39 of 103
Estuaries in the Balance
SECTION 4: REDFISH ANGLER
Video Viewing Guide: “Redfish Video”
As you watch the video, write your answers to these questions—you can pause the video or replay it
using the on-screen video controller.
1. Name three ways to fish for redfish.
2. What’s another name for redfish?
3. After drifting in the Gulf currents, what brings redfish larvae into the estuary?
4. What kinds of habitats do redfish larvae seek?
5. Name two things offered by seagrass beds for young redfish?
6. What general salinity levels does juvenile redfish prefer?
7. Under dry conditions, what areas within Corpus Christi Bay do redfish prefer?
8. Are redfish generally found close to shorelines or in open water?
9. How old are redfish when they leave estuaries for good?
10. What are the main causes of the decline redfish populations in the 1980s?
BACK TO TABLE OF CONTENTS
SECTION 4: REDFISH ANGLER
Page 40 of 103
Estuaries in the Balance
SECTION 4: REDFISH ANGLER
Additional Resources
Texas Parks and Wildlife Department
Texas Parks and Wildlife information about Redfish and the Texas Coastal Bend fishery http://www.tpwd.state.tx.us/fishboat/fish/didyouknow/reddrum.phtml
Another good site about the lifecycle of the Redfish from Texas Parks and Wildlife
http://www.tpwd.state.tx.us/huntwild/wild/species/reddrum/
Texas Park and Wildlife Freshwater Inflow Recommendations for the Nueces Estuary Technical but informative particularly the specific recommendations to restore freshwater
inflow needed to sustain estuarine habitats and species.
http://www.tpwd.state.tx.us/landwater/water/conservation/freshwater_inflow/nueces/
Seagrass Habitat issues and protection measures http://www.tpwd.state.tx.us/landwater/water/habitats/seagrass/redfish.phtml
Coastal Bend Bays and Estuaries Program
Corpus Christi Bay specific Master plan to protect and restore the Nueces River Delta from the
Coastal Bend Bays and Estuaries http://www.cbbep.org/graphics/NDPConceptualMasterPlan.pdf
GulfBase.org
GulfBase is a database of resources about the Gulf of Mexico. Facts and information about
Corpus Christi Bay http://www.gulfbase.org/bay/view.php?bid=ccb
Vocabulary
•
•
•
•
•
•
Angling - A method of fishing by means of an "angle" (fish hook). The hook is usually
attached to a fishing line and the line is often attached to a fishing rod. Angling is a principal
method of sport fishing, but commercial fisheries also use angling methods such as long
lining or trolling.
Bay(s) - A large, semi-enclosed body of water connected to an ocean through a tidal pass and
receiving fresh water from a river basin. A large bay may be called a gulf, a sea, a sound, or a
bight.
Catch limits - Fishing restrictions put in place to protect species from being overfished.
Delta - A river delta is a landform that is formed at the mouth of a river, where the river flows
into an ocean, sea, estuary, lake, or reservoir. Deltas are formed from the deposition of the
sediment carried by the river as the flow leaves the mouth of the river. Over long periods of
time, this deposition builds the characteristic geographic pattern of a river delta.
Estuarine - Of or having to do with the area where the sea meets a freshwater stream/river.
An oyster is an estuarine animal.
Fertilized - Fertilization is the fusion of gametes to produce a new organism. Depending on
the animal species, the process can occur within the body of the female in internal
fertilization, or outside (external fertilization). The entire process of development of new
individuals is called reproduction.
BACK TO TABLE OF CONTENTS
SECTION 4: REDFISH ANGLER
Estuaries in the Balance
Page 41 of 103
SECTION 4: REDFISH ANGLER
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Fish stocking - The practice of raising fish in a hatchery and releasing them into a river, lake,
or the ocean to supplement existing populations, or to create a population where none exists.
Fishery - An entity engaged in raising or harvesting fish.
Fly (fishing) - Fly-fishing is an angling method in which an artificial "fly" is used to catch
fish. The fly is cast using a fly rod, reel, and specialized weighted line.
Fly rod - A fishing pole is a long, flexible length of fiberglass, carbon fiber, graphite or,
classically, bamboo, used to catch fish.
Freshwater inflows (flows) - Freshwater generally refers to water, which collects within a
river basin and flows downstream from the inland sources. This water enters into the bay and
mixes with the more saline seawater, creating an estuary area that is less salty than the ocean.
Habitat(s) – An area that provides food, water and/or shelter for a particular species of
animal, plant, or other type of organism.
Inlets – A narrow body of water leading inland from a larger body of water, often leading to
an enclosed body of water, such as a sound, bay, lagoon, or marsh. In seacoasts, an inlet
usually refers to the actual connection between a bay and the ocean.
Jetties - A structure used in river, dock, and maritime works.
Juvenile(s) – An individual organism that has not yet reached its adult form, sexual maturity
or size. Juveniles sometimes look very different from the adult form.
Lagoon(s) - A shallow, elongated body of water separated from a larger body of water by
barrier islands or reefs.
Larva(l) - A distinct juvenile form many animals undergo before metamorphosis into adults.
The larva's appearance is generally very different from the adult form. A larva often has
unique structures and organs that do not occur in the adult form. Larvae are frequently
adapted to environments separate from adults. Some species such as barnacles are immobile
as adults, and use their mobile larval form to distribute themselves.
Marsh(es) or coastal marsh(es) - A type of wetland that is dominated by herbaceous rather
than woody plant species. Marshes often form a transition between the aquatic and terrestrial
ecosystems, are important nursery areas and highly productive.
Mudflats (tidal) - Also known as tidal flats, are coastal wetlands that form when tides or
rivers deposit mud. They are found in sheltered areas such as bays, bayous, lagoons, and
estuaries.
Nurseries - In marine environments, a nursery habitat is a subset of all habitats where
juveniles of a species occur, having a greater level of productivity per unit area than other
habitats. Mangroves, salt marshes and sea grass are typical nursery habitats for a range of
marine species.
Nutrient(s) - A chemical that an organism needs to live and grow.
Overfishing - The act whereby fish stocks are depleted to unacceptable levels, regardless of
water body size. The ability of a fishery to recover from overfishing depends on whether the
ecosystem's conditions are suitable for the recovery.
Oyster reef(s) - Reefs formed by oysters.
Population – All the organisms that both belong to the same group or species and live in the
same geographical area.
Redfish (or Red Drum) - An economically important game fish that is found in the Atlantic
Ocean from Massachusetts to Florida and in the Gulf of Mexico from Florida to Northern
Mexico.
BACK TO TABLE OF CONTENTS
SECTION 4: REDFISH ANGLER
Estuaries in the Balance
Page 42 of 103
SECTION 4: REDFISH ANGLER
•
•
•
•
•
•
•
•
•
Saline - Saline water is a general term for water that contains a significant concentration of
dissolved salts.
Salinity(ies) - The saltiness or dissolved salt concentration in water or within coastal soil.
Sea grass meadow(s) or bed(s) - Highly diverse and productive ecosystems that are nursery
grounds for many marine species.
Sea grass(es) - Flowering plants, which grow in marine environments.
Spawning season - Spawning is the process of releasing the eggs and sperm. Spawning often
happens during a particular annual season.
Sportfish - Sportfish are fish pursued for sport by recreational anglers. They can be
freshwater or marine fish.
Surfcasting - Fishing from the beach by casting into the surf at or near the shoreline.
Tide(s) - The rise and fall of sea levels caused by the combined effects of the gravitational
forces exerted by the Moon and the Sun and the rotation of the Earth.
Watershed(s) - An area of land that drains to a lake, stream or other body of water.
Extension Activities
1. Arrange a fieldtrip to the Nueces Delta Preserve http://nuecesdeltapreserve.org/fieldtrips.html
or the Texas State Aquarium http://www.texasstateaquarium.org/index.php/education/fieldtrips-and-camp-ins or a Fish Hatchery.
http://www.tpwd.state.tx.us/fishboat/fish/management/hatcheries/ccacpl.phtml
2. Arrange a field trip for your students through Texas A&M’s Center for Coastal Studies to
experience the estuary firsthand. http://ccs.tamucc.edu/aep/program.htm
3. Have a estuary expert visit your classroom from the University of Texas’ Marine Science
Institute, bringing hands-on activities for your students:
http://www.utmsi.utexas.edu/outreach.html
4. Students research other species of estuary sportfish that are related to the Redfish (Red Drum)
such as the Black Drum the Atlantic Croaker and the Seatrout. Have students compare and
contrast - what makes them the same and what makes them different. What does it take to be
a species of "drum?"
5. Small groups divide up and research freshwater needs of human communities and freshwater
needs of estuaries. Have each group make a case for why they need freshwater. Have them
come up with a plan for how to share fresh water between the two communities. Conservation
and water use behaviors and changing some behaviors, putting a value on the ecological
services estuaries provide, flood control, drought consequences for both communities, how to
value threatened or endangered species– these may be issues students consider.
6. Have students create an estuary "story board" depicting the lifecycle of the Redfish or other
estuarine species that lives in Corpus Christi Bay. Storyboard could include the habitats where
their chosen species lives at the different stages of its lifecycle.
7. Have students debate the right of the state of Texas to enact laws like the one protecting
seagrass in Redfish Bay. "Within the Redfish Bay State Scientific Area, no person shall
cause or allow any rooted seagrass plant to be uprooted or dug out from the bay bottom
by a submerged propeller, except as may be permitted by a coastal lease issued by the
Texas General Land Office or otherwise permitted under state law." Is it fair to tell
people what they can and cannot do with their boat? When is government regulation too great
a burden on individuals? When can the government act to protect species other than people?
BACK TO TABLE OF CONTENTS
SECTION 4: REDFISH ANGLER
Estuaries in the Balance
Page 43 of 103
SECTION 5: A WHOOPER’S TALE
Section 5: A Whooper’s Tale
A Whooper's Tale
This sub-module includes:
• Video: "A Whooper's Tale" (6 min. 20 sec.).
Tells the fascinating tale of a conservation
success story that is still unfolding. Explores
the Whooping Cranes’ life cycle as they make
annual visits to the Texas Coast.
• Interactive: ­ "Whooper Game"—students
learn to make good food choices for their
Whooper family in the Aransas National
Wildlife Refuge and what it takes to survive
as conditions change in the estuary.
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
Synopsis
This module focuses on the relationship between whooping crane survival and reproductive success,
salinity and freshwater inflows, and blue crabs. In the video, students learn about the plight of the
whooping crane, how it has made its way back from the brink of extinction, and why the Texas
Coastal Bend is so important to the species survival. In the interactive, students pretend they are a
whooping crane family. Each season they have to make good foraging decisions based on the food
available to build as much fat reserves as possible. If they are successful they will reproduce and raise
a chick with their mate. If they don’t make good choices or high quality food is just not available,
they may not produce a chick or they may not survive at all.
Big Idea
Endangered whooping cranes depend on the health of the estuary in between San Antonio Bay and
Copano Bay. Whooping Cranes must gain energy and fat reserves when they winter in and around the
Aransas National Wildlife Refuge. Blue crabs are an essential part of their diet. When not enough
freshwater flows into the estuary and salinities are high, blue crabs are not in the areas where
whooping cranes forage. Without this food source, whooping cranes are less likely to have a chick
and have it make its first migration, and, if conditions are really bad, to survive themselves.
Learning Objectives
1. Students accurately apply the concepts of high-energy food sources and energy use in the
Whooping Crane interactive to successfully grow the flock by three juveniles after six or
fewer rounds of the game.
2. Students will be able to accurately put typical, wet and dry years in order of best food
availability for whooping cranes.
3. Students will be able to identify at least three food sources for whooping cranes and will be
able to identify blue crabs as their most important food source.
4. Students will be able to project how long it might take for a whooping crane population of 50
individuals to double in number under typical conditions.
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Estuaries in the Balance
Page 44 of 103
SECTION 5: A WHOOPER’S TALE
5. Students will be able to successfully describe the relationship between freshwater inflow and
estuary salinity and how salinity affects food availability for whooping cranes.
6. Students will identify whooping cranes as endangered, will be able to define endangered, and
will understand that the population that spends winters in Texas is critical to the species
survival.
7. Students will be able to define migration, and on a map of North America, students will be able
to show that whooping cranes winter on the Texas coast and summer in Canada.
Suggested Sequence and Keys to Success:
Before Class
1. Begin by reading the background information (below) and visiting live links to other
resources that can be found just below the background information. Reviewing vocabulary
and the Whooper's Tale video script can help prepare you as well.
2. Print and make copies of the Video Viewing Guide question sheet for this module for each
student.
During Class
1. Use the Discussion Questions (below) before having students watch the “Whooper’s Tale
Video”. The questions will generate thinking about the sub-module’s themes.
2. Have students watch the video and complete the Video Viewing Guide questions. The latter
will help ensure that students understand key information needed to develop strategies for the
Interactives.
3. Students are now ready to play the Whooper Game individually, in small groups or as a class.
The interactive has a Help Screen that explains the game's goals and how to play.
Whooper Game - Students play the role of a whooping crane family that has recently
arrived on their wintering grounds. The students will choose the territory for their
crane family. When the game starts, students will click on three different types of food
icons to feed their family.
Students will need to make good food choices so the cranes can build energy reserves
for their spring migration. Some foods are more nutritious than others: Blue Crabs=5
energy units, Wolf Berries=4 energy units, Acorns=3 energy units. The cranes also
consume energy in different amounts while flying, walking, eating and resting, and
should conserve energy as much as possible. An energy meter on the right side of the
screen will track their progress. A score of 10 or higher means the whooping crane
family will grow.
Food quantities may change depending on the month and estuary salinity levels.
Salinity levels will change during each new season. Three different salinity scenarios
exist: Typical, Flood and Drought. In addition, “wildcards” will be offered to the
students randomly at the end of a season. Students may choose to take the card or skip
it. If they choose the wildcard, their family may increase, decrease, or stay the same.
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Page 45 of 103
Estuaries in the Balance
SECTION 5: A WHOOPER’S TALE
Background information
Recovering from a low of only 21 birds in the wild in the 1940s to over 450 birds today, the Whooping
Crane's recovery is one of conservation's most inspiring success stories.
Named for their loud, distinctive calls, whooping cranes (Grus americana) once lived throughout
much of North America. Though their range today is greatly reduced, whooping cranes still live in
parts of Canada and the United States.
Size
Whooping cranes are the tallest birds in North America. They stand five feet tall and have a seven to
eight foot wingspan. Because whooping cranes are adapted for flying, they weigh on average only 15
pounds.
Breeding
Whooping cranes may mate for life and can live 25 years or more in the wild. Unlike herons and
egrets that nest and perch in trees, whooping cranes do neither; they roost and nest in shallow water.
On summer nesting grounds, a pair establishes a territory, which they defend from other cranes. The
pair performs elaborate courtship dances and calls. If mating is successful, the female usually lays two
eggs. Both the female and male take turns incubating the eggs for
approximately 30 days. Although both eggs may hatch, only one chick
usually survives the first few months.
Chicks grow very fast, up to an inch per day during their first summer,
in order to be large and strong enough to migrate only a few months
after hatching. Young cranes learn the migration route by following
their parents south in the fall.
The chicks join juvenile flocks during their second summer and remain
with other unmated birds in these groups until they are three to five
years old. Pairing often begins within these flocks. A new pair will
claim a nesting territory and begin to raise chicks of their own.
Whooping Crane History
Cranes are among the oldest living bird species on Earth. Historically, whooping cranes ranged
widely and relied on diverse wetland ecosystems for overwintering, breeding and migration stopovers.
Whooping crane fossils have been found throughout much of North America, from southern Canada
to Mexico. The population has gone from an estimated 10,000 birds before the settling of Europeans
on the continent to 1,200-1,400 birds by 1865 to 21 in 1944.
Reasons for Decline
The two most important factors that contributed to the decline of whooping cranes were habitat loss
and unregulated hunting. As European settlers expanded westward, they drained marshes and plowed
prairies for agriculture, destroying much of the birds’ nesting habitat. Many remaining habitats were
close to human disturbance, a stress to which this shy and secretive species was unable to adjust. As
the number of whooping cranes declined, hunters, hobbyists, and museum collectors scrambled to
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Estuaries in the Balance
Page 46 of 103
SECTION 5: A WHOOPER’S TALE
acquire the rare specimens and eggs for their collections. By 1890, whooping cranes had disappeared
from the heart of their breeding range in the north central United States. In 1918 the passage of the
Migratory Bird Treaty Act made it illegal to hunt Whooping Cranes. However, despite this and other
early protection efforts the whooping crane population continued to decline. By 1938, only two small
flocks remained—one non-migratory flock in southwest Louisiana, and one migratory flock that
nested in Canada and wintered in Texas.
The migratory population was reduced to approximately 16 birds in 1941, with an additional six
whooping cranes surviving in the Louisiana flock. By 1950, severe weather had decimated the
Louisiana population, leaving only the one small migratory flock. Whooping cranes were on the brink
of extinction. Only one small population of whooping cranes once stood between survival and
extinction. Ambitious recovery efforts were needed to save the species. Projects to protect the species
and to create new populations were needed to begin the whooping cranes’ long journey to recovery.
The Last Wild Population
Hope for the survival of whooping cranes depended on the wild population that migrated from the
wilderness of Canada to the Gulf coast of Texas each winter. In 1937, their wintering grounds were
protected with the creation of the Aransas National Wildlife Refuge (NWR). However, their breeding
grounds, 2,500 miles to the north, remained a mystery until a fire crew flying over Wood Buffalo
National Park in Canada’s Northwest Territories accidentally discovered them in 1954.
The discovery of the species’ only remaining breeding grounds opened new options to save these
birds from extinction. Because whooping cranes lay two eggs per clutch, but usually only raise a
single chick, scientists believed that one egg could be removed from each nest without decreasing the
productivity of the wild flock. Egg collection occurred during 1967-1996. The eggs became the
foundation for future captive breeding and release programs in North America.
Due in part to habitat protection and hunting restrictions, this remnant wild population has made a
dramatic recovery. More than 260 whooping cranes now migrate between Canada and Texas.
Captive Breeding
In 1975 the U.S. Geological Survey’s Patuxent Wildlife Research Center in Maryland began
successfully breeding whooping cranes in captivity. To reduce the likelihood of a catastrophic event
wiping out the entire captive population, Patuxent transferred 22 whooping cranes to the International
Crane Foundation (ICF) in Baraboo, Wisconsin in 1989.
The ability to breed whooping cranes in captivity increased the species’ chances of survival. Captive
breeding and reintroduction efforts became a possibility with the development of new chick-rearing
techniques.
Captive breeding is currently underway at ICF, Patuxent, Audubon Species Survival Center in New
Orleans, and the Calgary and San Antonio zoos.
Recovery Plan
A Whooping Crane Recovery Plan was developed to chart a course for saving whooping cranes from
extinction. The Whooping Crane Recovery Team, a group of crane biologists and officials from the
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Page 47 of 103
Estuaries in the Balance
SECTION 5: A WHOOPER’S TALE
United States and Canada, created the plan. If the recovery plan is successful, the species could be
downlisted from endangered to threatened status by the U.S. Fish and Wildlife Service.
The recovery strategy includes: protecting breeding, wintering, and migration habitat; protecting and
facilitating the growth of the current wild population; establishing two additional self-sustaining
populations of whooping cranes in the wild in North America; and maintaining a genetically healthy
captive population.
Over the last 35 years a series of reintroduction projects have been developed to establish new wild
whooping crane populations. The projects have had varying success, but as each project builds on
previous attempts, we are learning what techniques work most effectively. Today, as a result of years
of dedication, a second whooping crane population numbering over 100 birds migrates through the
eastern United States, and a non-migratory population of more than 25 cranes has been re-established
in Louisiana.
Whooping Cranes in Texas
The Guadalupe River supplies freshwater to the coastal marshes of the Gulf of Mexico and the
wintering area of the last naturally occurring whooping crane population at Aransas NWR. The
freshwater from the Guadalupe River is essential for the cranes and their main winter food source,
blue crabs, but the river and coastal wetlands are threatened by excessive upstream water use.
The survival of whooping cranes in Texas depends on securing freshwater from the Guadalupe River
basin and conserving wetland habitats along the Gulf Coast. These same waters also sustain a wealth
of economic activity along the Texas coast, including commercial and sport fisheries, shellfisheries
and recreation.
On their wintering grounds along the Gulf Coast of Texas,
whooping cranes eat a varied diet of wolfberries, clams,
insects, acorns, and snakes in addition to their most nutritious
and important food source, blue crabs. The coastal marshes
provide excellent habitat for the crabs if salinity levels remain
moderate, which is determined primarily by the amount of
freshwater flowing into the coastal waters from the Guadalupe
River basin.
When freshwater is reduced, due to drought or use of the
river's water upstream, fewer crabs are available for whooping cranes. In such cases, the cranes
weaken, resulting in higher mortality on their wintering grounds and fewer chicks on their breeding
grounds in Canada the following spring. How will this affect the future of this endangered species?
During the winter of 2008-09, a prolonged drought coupled with upstream water use resulted in
insufficient freshwater inflows to the coastal marshes of southeast Texas. Continued upstream use of
water resulted in a longer period of very high salinity levels along the coast than would have been the
case under natural conditions. When the cranes arrived from their long migration, many former
feeding areas were either dry or had few crabs. Some cranes were forced to move to other wetlands in
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Estuaries in the Balance
Page 48 of 103
SECTION 5: A WHOOPER’S TALE
search of food and drinking water, and others died on their territories. That winter, 23, or 8.5% of the
total population of the 273 cranes, perished.
Droughts are natural in the southwest, and the whooping crane population can recover from such
setbacks when they occur infrequently. However, the State of Texas is granting permits for upstream
water withdrawal from the Guadalupe basin to such an extent that freshwater inflows to the coast are
expected to be significantly reduced or even eliminated on a much more frequent basis. At the same
time, the continued loss and degradation of key wetland sites further limits the potential for the
whooping crane population to find suitable habitats along the coast. We expect increasing mortality of
cranes in the coming years, and possible extinction of the flock, unless a more sustainable approach to
water and wetland management is undertaken.
Global Climate Change and Sea-level Rise
Current and predicted sea-level rise could also have a dramatic effect on the whooping crane
population. Sea-level changes are a natural factor of our coastal environments and related to
the global changes of temperature and resulting melting and freezing of the ice caps and
glaciers. The current sea-level rise is estimated to be about 6 mm per year, however, that
value increases and decreases depending on landform shapes and connectivity to the ocean. In
addition, the submergence of land in delta areas and along shorelines that is due to compaction
of underground soil layers and from human activities (extraction of water, oil, gas) can
increase sea-level rise amounts (called subsidence).
Scientists studying global climate change predict an increase in sea-level rise in the next
century, due to both natural processes and human activities. As low-lying areas along the
coast are inundated with seawater, habitats are converted from upland to wetland, wetland to
seagrass, seagrass to unvegetated bay bottoms. If this progression of conversion is halted by a
natural bluff or from bulkheads and seawalls constructed during development, habitat loss
occurs and animals depending on that habitat are negatively impacted. These natural coastal
areas are important to people living or visiting the coast, as it provides protection from waves
and storms. In addition, most of the coastal organisms depend on these habitats for food,
shelter and reproduction; thus, these areas are essential to maintain productivity and diversity
to coastal ecosystems.
To address all these critical issues, conservation organizations, universities, and government agencies
are undertaking new research and outreach activities aimed at securing the long-term survival of
whooping cranes on their wintering grounds, and – by extension – the coastal economy of
southeastern Texas.
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Estuaries in the Balance
Page 49 of 103
SECTION 5: A WHOOPER’S TALE
Pre/Post Video Discussion Questions
1. What effect has the Endangered Species Act had on whooping cranes?
2. What were some of the causes of the whooping cranes’ decline?
3. Where does the last wild, naturally occurring population of whooping cranes breed? Where do
they spend the winter?
4. What is the most important food source for whooping cranes while on their winter territories?
What are some additional food sources?
5. Why is this food source so important for whooping cranes? What happens if they can’t find this
food source?
6. How does freshwater inflow and salinity levels affect the cranes’ food source?
7. What are some of the natural and human-caused challenges to the coastal estuaries where the
whooping cranes winter?
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Page 50 of 103
Estuaries in the Balance
SECTION 5: A WHOOPER’S TALE
Video Viewing Guide: “A Whooper’s Tale”
As you watch the video, write your answers to these questions—you can pause the video or replay it
using the on-screen video controller.
1. Name three things unusual about whooping cranes.
2. How many whooping cranes were living when their population was at its greatest? How many
when it was at its lowest number? How many whooping cranes are there today?
3. How many species of cranes are there worldwide?
4. In which Coastal Bend estuary habitats are whooping crane territories found?
5. Name three reasons whooping cranes need a rich diet.
6. What is the most nutritious and important food source for whooping cranes?
7. Name three food items eaten by whoopers in upland areas. Are these more or less nutritious
than blue crabs and wolf berries?
8. Under what conditions are whooping cranes likely to have to feed more often in upland areas?
9. Name two reasons that having to fly frequently to upland areas can make it more challenging
for whoopers to fatten up for their spring migrations.
10. Of all human impacts on the whooping crane’s wintering grounds, which poses the greatest
threat?
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Page 51 of 103
Estuaries in the Balance
SECTION 5: A WHOOPER’S TALE
Additional Resources
The International Crane Foundation (ICF) is the world’s center for the study and conservation of
cranes. The following pages provide additional background information on the whooping crane:
• General information: http://www.savingcranes.org/whooping-crane.html
• Conservation efforts to restore whooping cranes in North America:
http://www.savingcranes.org/whooping-crane-conservation.html
• Whooping crane conservation in Texas:
http://www.savingcranes.org/guadalupe-river.html
• The importance of freshwater inflows and blue crabs to whooping cranes:
http://www.savingcranes.org/images/stories/pdf/conservation/2009V35N3.pdf
http://www.savingcranes.org/images/stories/pdf/conservation/2010v36n2.pdf
http://www.savingcranes.org/images/stories/pdf/2011v37n4.pdf
Whooping crane fact sheet from Texas Parks and Wildlife Department:
http://www.tpwd.state.tx.us/publications/pwdpubs/media/pwd_bk_w7000_0013_whooping_crane.pdf
Information on whooping cranes at Aransas National Wildlife Refuge:
http://www.fws.gov/southwest/refuges/texas/aransas/whoopingcranes.html
Vocabulary
•
•
•
•
•
•
•
•
•
•
Barge(s) - A flat-bottomed boat, built mainly for river and canal transport of heavy goods.
Blue Crabs (Eastern blue crabs) - A species of crab native to the waters of the western
Atlantic Ocean, the Pacific coast of Central America and the Gulf of Mexico. The blue crab is
an important part of the estuarine food web, and of significant seafood value and economic
importance in the United States.
Captivity - Animals that live under human care are in captivity. Captivity can be used as a
generalizing term to describe the keeping of either domesticated animals (livestock and pets)
or wild animals.
Cargo(es) - Goods or produce transported, generally for commercial gain, by ship or aircraft.
Climate - The statistics of temperature, humidity, atmospheric pressure, wind, precipitation,
atmospheric particle count and other meteorological elemental measurements in a given region
over long periods.
Contaminants - Impurities are substances inside a confined amount of liquid, gas, or solid,
which differ from the chemical composition of the material or compound.
Estuary(ies) – A partly enclosed coastal body of water with one or more rivers or streams
flowing into it, and with a free connection to the open sea. Estuaries are amongst the most
heavily populated areas throughout the world, with about 60% of the world’s population living
along estuaries and the coast. As a result, estuaries are suffering degradation by many factors.
Extinction - In biology and ecology, extinction is the end of an organism or of a group of
organisms, normally a species.
Flock(s) - A group of birds typically engaged in a similar behavior in flight, or while foraging.
Foraging - Searching for and exploiting food resources. It affects an animal's fitness because
it plays an important role in an animal's ability to survive and reproduce.
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Estuaries in the Balance
Page 52 of 103
SECTION 5: A WHOOPER’S TALE
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Freshwater (fresh water) - Naturally occurring water on the Earth's surface in ice sheets, ice
caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in
aquifers and underground streams. Fresh water is generally characterized by having low
concentrations of dissolved salts and other total dissolved solids.
Freshwater inflows (flows) - Freshwater generally refers to water, which collects within a
river basin and flows downstream from the inland sources. This water enters into the bay and
mixes with the more saline seawater, creating an estuary area that is less salty than the ocean.
Habitat(s) – An area that provides food, water and/or shelter for a particular species of
animal, plant, or other type of organism.
Intercoastal waterway - A 3,000-mile waterway along the Atlantic and Gulf coasts of the
United States. It provides a navigable route along its length without many of the hazards of
travel on the open sea.
Marsh(es) or coastal marsh(es) - A type of wetland that is dominated by herbaceous rather
than woody plant species. Marshes often form a transition between the aquatic and terrestrial
ecosystems, are important nursery areas and highly productive.
Mated pair(s) - Breeding pair is a pair of animals, which cooperate over time to produce
offspring with some form of a bond between the individuals. For example, many birds mate
for a breeding season or sometimes for life. They may share some or all of the tasks involved:
building a nest, incubating the eggs and feeding and protecting the young.
Population – All the organisms that both belong to the same group or species and live in the
same geographical area.
Range(s) - In a set of data, the range is the difference between the largest and smallest values.
Reintroduced - Reintroduction is the deliberate release of a species into the wild, from
captivity or relocated from other areas where the species survives. A species that needs
reintroduction is usually one whose existence has become threatened or endangered in the
wild.
River basins - An extent or an area of land where surface water from rain and melting snow
or ice converges to a single point, usually the exit of the basin, where the waters join another
water body, such as a river, lake, reservoir, estuary, wetland, sea, or ocean.
Saline - Saline water is a general term for water that contains a significant concentration of
dissolved salts.
Salinity(ies) - The saltiness or dissolved salt concentration in water or within coastal soil.
Territory - An area that an animal of a particular species consistently defends against others.
Animals that defend territories in this way are referred to as territorial.
Tidal ponds - Pools of seawater created when the tide recedes.
Unison call(s) – A call made by pair-bonded cranes. It gets its name because both the male
and female call in unison with each other.
Watershed(s) - An area of land that drains to a lake, stream or other body of water.
Windpipe - A tube that connects the pharynx and larynx to the lungs, allowing the passage of
air.
Wingspan - The distance from one wingtip to the other wingtip.
Extension Activities
1. Arrange a field trip for your students to view whooping cranes and experience the estuary
firsthand: http://www.whoopingcranetours.com, http://ccs.tamucc.edu/aep/program.htm
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Page 53 of 103
Estuaries in the Balance
SECTION 5: A WHOOPER’S TALE
2. Have a whooping crane expert visit your classroom (for free!) bringing hands-on activities for
your students: http://www.savingcranes.org/outreach-2.html
3. Small groups research current threats to whooping cranes: lack of freshwater inflows, power
line collisions, illegal shooting, oil and chemical spill effects, disease, hurricanes, invasive
species (black mangrove), and sea level rise. Have groups present to the class on their
particular threat. Brainstorm as a class what can be done to prevent some of these threats from
occurring.
4. Arrange a field trip for your students through Texas A&M’s Center for Coastal Studies to
experience the estuary firsthand. http://ccs.tamucc.edu/aep/program.htm
5. Have a estuary expert visit your classroom from the University of Texas’ Marine Science
Institute, bringing hands-on activities for your students:
http://www.utmsi.utexas.edu/outreach.html
6. Students create a storyboard using illustrations and text depicting the lifecycle and migration
of a whooping crane family.
7. Students create a timeline illustrating the history of whooping cranes, including issues that led
to their near-extinction and past and current conservation efforts to restore whooping crane
populations.
8. Have students research the Endangered Species Act and/or the Migratory Bird Treaty Act and
events leading to the passage of these legislative acts.
9. Have students create crane-related artwork for the International Crane Foundation’s
International Art Exchange program, which connects students from different parts of the world
through their artwork. Contact: Joan Garland, [email protected].
Additional Activities
Crane and wetland related activities and curriculum for grades K-12 from the International Crane
Foundation: http://www.savingcranes.org/activity-packets.html
Crane and wetland bibliographies from the International Crane Foundation:
http://www.savingcranes.org/bibliographies-3.html
Whooping crane curriculum and activities from the Wisconsin Department of Natural Resources:
http://dnr.wi.gov/files/PDF/pubs/ER/ER0661.pdf
Water conservation activity from the Whooping Crane Eastern Partnership, an international
coalition of public and private organizations that is reintroducing whooping cranes to the eastern
U.S.: http://www.bringbackthecranes.org/getinvolved/educators/freshwater.html
Information on the Texas Whooper Watch program developed by Texas Parks and Wildlife
Department - The program seeks the help of citizen scientists in identifying whooping crane
migration stopover sites and non-traditional wintering areas:
http://www.tpwd.state.tx.us/huntwild/wild/wildlife_diversity/texas_nature_trackers/whooperwatch/
Whooping crane information and activities from Journey North, an online environmental
education program that engages students and citizen scientists around the globe in tracking
wildlife migration and seasonal change: http://www.learner.org/jnorth/tm/crane/indexCurrent.html
BACK TO TABLE OF CONTENTS
SECTION 5: A WHOOPER’S TALE
Page 54 of 103
Estuaries in the Balance
SECTION 6: ESTUARIES IN THE BALANCE
Section 6: Estuaries In the Balance Video
Estuaries in the Balance
Concluding Video (7 min. 53 sec.) includes:
• Estuary Resources: how humans use estuary
resources in general and in the Texas Coastal
Bend.
• Ecological Services: the benefits that
estuaries provide human and natural
communities.
• Issues and Threats: for all estuaries and in
the Texas Coastal Bend region.
• Recovery and Sustainability: renewing
estuary ecosystems in general, throughout
Texas and along the Texas Coastal Bend.
• TEKS: 4th grade, 5th grade, 6th grade, 7th
grade, 8th grade
Synopsis
The plants and animals that are either seasonal visitors or live full-time in estuaries need a healthy,
productive estuary ecosystem—but so do people too. Estuaries provide many "ecological services"
like abundant seafood, shoreline protection, natural water purification, and recreation activities like
fishing and bird watching, and all these benefit human communities. Habitat destruction, pollution,
over-fishing and dredging, sea level rise due to climate change and reducing freshwater inflow to the
bays are examples of some of the damage humans have caused in these vital ecosystems. Increasing
water use by growing populations in South Central Texas will place increasing stresses on Coastal
Bend estuaries in the years to come. For estuaries to thrive, individuals and communities will need to
manage water resources wisely.
Big Idea
Human and natural communities both need healthy estuaries. Humans have the capacity to disrupt the
ecological balance or to sustain it.
Learning Objectives
Students will demonstrate understanding of:
1. the value of estuaries to human communities by accurately identifying five key ecological
services that estuaries provide.
2. the negative human impacts on estuaries by accurately identifying six human activities that
have historically or which continue to damage estuary ecosystems.
3. how individuals and human communities can protect ecosystems by accurately identifying three
strategies that will benefit estuary ecosystems.
4. how they value the choices that individuals and communities make that positively and
negatively affect both human and natural communities through informal discussion following
the video.
BACK TO TABLE OF CONTENTS
SECTION 6: ESTUARIES IN THE BALANCE
Page 55 of 103
Estuaries in the Balance
SECTION 6: ESTUARIES IN THE BALANCE
Suggested Sequence and Keys to Success
Before Class
1. This is the final video. Teachers who followed the suggested sequence have guided
students through four videos and five Interactives. This video can stand-alone but is
designed to help students integrate the content they've learned with value exploration as
they consider how they can make a difference. Teachers may want to begin by reading the
background information (below) and visiting live links to other resources found just after
the background information. Reviewing vocabulary and the Estuaries in the Balance video
script can help prepare you as well.
2. Print and make copies of the Video Viewing Guide question sheet for this module for each
student.
During Class
1. Use the Discussion Questions (below) before having students watch the Estuaries in the
Balance video. The questions will generate thinking about the sub-module’s themes.
2. Have students watch the video and complete the Video Viewing Guide questions.
Background information
Humans have lived near and along Texas Coastal Bend Estuaries for over 10,000 years. Evidence of
ancient settlements and tools used for fishing and harvesting estuary resources has been discovered at
sites along the four estuaries covered in this module. When Spanish explorers first arrived, the
Karankawa and Copane, among many other native tribes, were living in bands and family groups
along the Texas Coastal Bend. They harvested many estuary species for food including oysters, as
evidenced by mounds or "middens" of discarded shells still visible today. They had technologies that
fit their time and culture and that provided food and shelter for their families. Although they
exploited the estuary for the resources they needed, their "human footprint" was light compared to
later arrivals from Mexico, Europe and the United States. The changes have been dramatic in the 300
years of human activities that followed.
Modern human habitation and economic development along the Texas Coastal Bend has altered the
landscape as well as the dynamics of the natural system. Dredging the Gulf Intracoastal Waterway,
opening additional passes between bays and the Gulf, historical dredging of oyster beds for roadbuilding material, filling in wetlands for industrial, residential and agricultural uses are a few
examples of physical changes to the land and bay formations that support the coastal ecosystems.
The quantity of water entering coastal wetlands and the estuaries has been reduced as the population
of Texas and in particular, South Central Texas has swelled. Water needs and use upstream have
greatly increased. Population trends indicate that the population in Texas will double between 2000
and 2050. That means that some of the water that used to flow unchallenged down Texas rivers to
refresh the estuaries, bringing the nutrients and sediments that sustain estuary ecosystems, is
diverted for human use. Dams upstream have reduced age-old seasonal patterns of over-bank floods
that replenished soils and large pulses of river water that delivered fresh water far into the estuaries.
Human communities living in the watersheds benefit from flood control and the hydropower that
dams provide but not without a cost to river, estuary, and bay ecosystems.
BACK TO TABLE OF CONTENTS
SECTION 6: ESTUARIES IN THE BALANCE
Page 56 of 103
Estuaries in the Balance
SECTION 6: ESTUARIES IN THE BALANCE
Water quality suffers too as this growing population contributes polluted urban and agricultural
runoff, fertilizers, pesticides, fecal contamination from septic tanks and livestock yards, and even
antibiotics and other drugs that are expelled from our bodies as waste or simply dumped into the
toilet. Closer to the coast, refining, storage and transporting oils, gas and chemicals poses both real
and potential dangers to air and water quality as do more catastrophic events like the Deep Horizon
disaster in the Gulf of Mexico. Wetlands, marsh grasses, and even oysters help clean contaminated
water but they can only do so much before the habitats and the species that live there are harmed.
Texans are working locally, regionally and statewide to manage the limited water resources.
Historically, the voices of the plants and animals that call Texas home have not been heard above the
clamor for human use of these water resources. More and more, a credible argument is being made
that natural systems like estuaries produce valuable environmental services that can be measured in
dollars and cents. Services like cleaning the water, reducing shoreline erosion, abating hurricane
damage to towns and cities, providing abundant seafood for local consumption and attracting a
booming fishing, birding and recreational industry. Adding up these benefits results in billions of
dollars for the Texas economy each and every year. And that's just one way of looking at it.
What is the value of majestic Whooping Cranes soaring overhead on their way to their winter home
on the Texas Coastal Bend? What would be the "lost value" if this species was again driven to near
or even actual extinction? What about the loss of even a part of incredible diversity of creatures
whose lives, some at the most vulnerable early stages of their lifecycle, depend on the right mix of
fresh and salt water in the estuary in habitats that are found no where else on earth? How do
individuals and societies choose to value these kinds of things?
Clarifying and sorting through these kinds of values with students is not without some risk. It's also
unavoidable if the goals of education include graduating students who will lead responsible and
active civic lives. Texas standards support giving students many opportunities to practice critical
thinking skills in the classroom. Today's students will be better prepared to contribute if they grapple
now with the science, the issues, and their own beliefs about what they value most in the complex
ecosystems that they are part of. Here on the Texas Coastal Bend, estuaries are truly, in the balance.
BACK TO TABLE OF CONTENTS
SECTION 6: ESTUARIES IN THE BALANCE
Page 57 of 103
Estuaries in the Balance
SECTION 6: ESTUARIES IN THE BALANCE
Pre/Post Video Discussion Questions
• What kinds of benefits do estuaries provide to people? Can you put a dollar value on them?
What kinds of benefits are hard to measure in dollars and cents? Why is that important to
you? Does anyone else feel differently?
• What kinds of human activities harm or have the potential to harm natural communities like
estuaries? What kinds of those activities happen here on the Coastal Bend? What kinds
happen somewhere else but have an effect on estuaries? What benefits do people get from
some of those activities you mentioned? Is it possible to have human activities that actually
help natural communities and human communities at the same time? What if there is a tradeoff - how do you make that decision?
• What kinds of choices have you personally made that you think have a positive effect on
natural communities? A negative effect? Can you name what any of those would be?
• What kinds of choices does your community make that have a positive effect on natural
communities? A negative affect? Can you name what those would be?
• What kinds of decisions that are made at the state level in Texas have a positive effect on
natural communities? A negative effect? Can you name what those would be?
• If you could change something that you do—say a way you now use water—what would that
be? How many of you think that would be a choice you might make yourself? Why? Why
not? How many of you think that would not be a choice you would make. Why? Why not?
• The Texas Coastal Bend is home to species of plants and animals that are doing fine, some that
are at risk, and some that are just back from near-extinction like the whooping crane. How do
you feel about endangered species like the whooping crane? Can anyone remember why the
whooping cranes are at risk? How about oysters? Redfish? Blue crabs? How have human
communities contributed to the problem? How about the solutions? What are some of the
strategies that help these species thrive?
BACK TO TABLE OF CONTENTS
SECTION 6: ESTUARIES IN THE BALANCE
Page 58 of 103
Estuaries in the Balance
SECTION 6: ESTUARIES IN THE BALANCE
Video Viewing Guide: “Estuaries in the Balance” video
As you watch the video, write your answers to these questions—you can pause the video or replay it
using the on-screen video controller.
1. How many of the world’s largest cities are built on estuaries?
2. What is the annual economic value of the natural resources and services provided by San
Antonio Bay?
3. Name four ways that humans benefit from estuaries and their species.
4. Name three ways that oysters and oyster beds benefit humans.
5. When were the first fishing restrictions put in place in Texas?
6. How much has Texas’ oyster population dropped?
7. How much has blue crab populations declined in the last 20 years? Name two causes of this
decline.
8. If human water use reduces freshwater inflows to estuaries, name one impact on the health of
each of these species:
• blue crabs:
•
oysters:
•
redfish:
•
whooping cranes:
9. Between 2000 and 2050 Texas’ population will grow from _____________ to _____________.
10. Name three important strategies for increasing freshwater flows in the future.
BACK TO TABLE OF CONTENTS
SECTION 6: ESTUARIES IN THE BALANCE
Page 59 of 103
Estuaries in the Balance
SECTION 6: ESTUARIES IN THE BALANCE
Additional Resources
National Estuarine Research Reserve System
This site is student-friendly and dedicated to educating about estuaries. This page is specific to
addressing the following question with your students: " How are Estuaries Connected to My
Life?" http://estuaries.noaa.gov/About/Default.aspx?ID=243
United Nations Education, Scientific and Cultural Organization
This site offers educators resources to explore values with students around the issues of a
sustainable future. http://www.unesco.org/education/tlsf/mods/theme_d/mod22.html
Vocabulary
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Algae - Microscopic, single cell plants found in a variety of aquatic environments.
Angler(s) - A fisherman who uses the fishing technique of angling.
Aquatic - Relating to water; living in or near water, taking place in water.
Bacteria - A large domain of microorganisms. Typically a few micrometers in length,
bacteria are present in most habitats on the planet.
Barrier island(s) - A coastal landform and a type of barrier system composed of relatively
narrow strips of sand that is parallel to the mainland coast. They usually occur in chains.
Bay(s) - A large, semi-enclosed body of water connected to an ocean through a tidal pass and
receiving fresh water from a river basin. A large bay may be called a gulf, a sea, a sound, or a
bight.
Biofilm - An aggregate of microorganisms in which cells adhere to each other on a surface.
Blue Crabs (Eastern blue crabs) - A species of crab native to the waters of the western
Atlantic Ocean, the Pacific coast of Central America and the Gulf of Mexico. The blue crab is
an important part of the estuarine food web, and of significant seafood value and economic
importance in the United States.
Citizens - Citizenship denotes the link between a person and a state and is associated with the
right to work and live in a country and to participate in political life.
Climate change - Changes in climate due to human activities that includes an overall increase
in world temperatures caused by additional.
Desalination - Refers to any of several processes that remove some amount of salt and other
minerals from saline water. Salt water is desalinated to produce fresh water suitable for
human consumption or irrigation.
Dredge(d)(ing) - Dredging is an excavation activity usually carried out at least partly
underwater with the purpose of gathering up bottom sediments and disposing of them at a
different location. This technique is often used to keep waterways navigable. Dredging is also
used as a technique for fishing for certain species of edible clams, oysters, and crabs.
Drought(s) - An extended period of months or years when a region receives consistently
below average precipitation. It can have a substantial impact on the ecosystem and agriculture
of the affected region. Even a short, intense drought can cause significant damage and harm
the local economy.
Ecological services - Humankind benefits from a multitude of resources and processes that
are supplied by natural ecosystems. Collectively, these benefits are known as ecosystem
services and include products like clean drinking water and processes such as the
decomposition of wastes.
BACK TO TABLE OF CONTENTS
SECTION 6: ESTUARIES IN THE BALANCE
Page 60 of 103
Estuaries in the Balance
SECTION 6: ESTUARIES IN THE BALANCE
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Ecosystem(s) - A system formed by the interaction of a community of organisms with their
physical environment.
Endangered - An endangered species is a population of organisms which is facing a high risk
of becoming extinct because it is either few in numbers, or threatened by changing
environmental or predation parameters.
Erosion - Condition in which the earth's surface is worn away by the action of water and/or
wind.
Estuary(ies) - A partly enclosed coastal body of water with one or more rivers or streams
flowing into it, and with a free connection to the open sea. Estuaries are amongst the most
heavily populated areas throughout the world, with about 60% of the world’s population
living along estuaries and the coast. As a result, estuaries are suffering degradation by many
factors.
Evaporation - Liquid water becoming a gas.
Filter (feeders) - Filter feeders are animals that feed by straining suspended matter and food
particles from water. Filter feeders can play an important role in clarifying water.
Food chain - A community of organisms representative of the eating relationships between
species where each member is eaten in turn by another member.
Freshwater inflows (flows) - Freshwater generally refers to water, which collects within a
river basin and flows downstream from the inland sources. This water enters into the bay and
mixes with the more saline seawater, creating an estuary area that is less salty than the ocean.
Game fish - Fish pursued for sport by recreational anglers.
Human footprint - The ecological footprint is a measure of human demand on the Earth's
ecosystems.
Industry(ies) - The production of an economic good or service within an economy.
Marsh(es) or coastal marsh(es) - A type of wetland that is dominated by herbaceous rather
than woody plant species. Marshes often form a transition between the aquatic and terrestrial
ecosystems, are important nursery areas and highly productive.
Migration(s) - Bird migration is the regular annual seasonal journey undertaken by many
species of birds. Bird movements include those made in response to changes in food
availability, habitat, or weather.
Mollusks - A large group of invertebrate animals. Around 85,000 species are recognized.
Because mollusks have such a varied range of body structures, it is difficult to find defining
characteristics to apply to all modern groups. The two most universal features are a mantle
with a significant cavity used for breathing and excretion, and the structure of the nervous
system.
Natural heritage - Heritage is that which is inherited from past generations, maintained in the
present and bestowed for the benefit of future generations. Natural heritage is the legacy of
natural objects and intangible attributes encompassing the countryside and natural
environment, including plants and animals or biodiversity.
Nutrient(s) - A chemical that an organism needs to live and grow.
Overfishing - The act whereby fish stocks are depleted to unacceptable levels, regardless of
water body size. The ability of a fishery to recover from overfishing depends on whether the
ecosystem's conditions are suitable for the recovery.
Oyster reef(s) - Reefs formed by oysters.
BACK TO TABLE OF CONTENTS
SECTION 6: ESTUARIES IN THE BALANCE
Page 61 of 103
Estuaries in the Balance
SECTION 6: ESTUARIES IN THE BALANCE
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Oyster(s) (Eastern Oyster(s)) - A group of bivalve mollusks, which live in marine or
brackish habitats. Humans commonly consume some kinds of oyster as a delicacy. Other
kinds are harvested for the pearl produced within the mantle.
Phytoplankton - Photosynthesizing microscopic organisms that drift the upper sunlit layer of
almost all oceans and bodies of fresh water. They are agents for "primary production" and
account for half of all photosynthetic activity on Earth.
Pollutant(s) - Harmful substances introduced to air, soil, or water.
Population – All the organisms that both belong to the same group or species and live in the
same geographical area.
Protein - Large biological molecules consisting of one or more chains of amino acids.
Proteins perform a vast array of functions within living organisms.
Redfish (or Red Drum) - An economically important game fish that is found in the Atlantic
Ocean from Massachusetts to Florida and in the Gulf of Mexico from Florida to Northern
Mexico.
Reservoir(s) - An artificial lake or impoundment from a dam used to store water.
Seagrass meadow(s) or bed(s) - Highly diverse and productive ecosystems that are nursery
grounds for many marine species.
Seagrass(es) - Flowering plants, which grow in marine environments.
Sport fish - Game fish are fish pursued for sport by recreational anglers. They can be
freshwater or marine fish.
Tarpon - Large fish of the genus Megalops.
Water conservation - Planned management of water resources to prevent exploitation,
destruction or neglect.
Water quality - The chemical, physical and biological characteristics of water. The most
common standards used to assess water quality relate to health of ecosystems, safety of
human contact and drinking water.
Water recycling - Wastewater cleaned for re-use, usually for non-potable purposes such as
irrigating landscape and refilling aquifers.
Watershed(s) - An area of land that drains to a lake, stream or other body of water.
Wetlands - An area of land whose soil is saturated with moisture either permanently or
seasonally.
Extension Activities
1. Arrange a field trip for your students through Texas A&M’s Center for Coastal Studies to
experience the estuary firsthand. http://ccs.tamucc.edu/aep/program.htm
2. Have a estuary expert visit your classroom from the University of Texas’ Marine Science
Institute, bringing hands-on activities for your students:
http://www.utmsi.utexas.edu/outreach.html
3. In small groups, students investigate local, regional or state issues that affect the estuaries
nearest to your home area. Students can identify human behaviors that have negative and
positive effects on estuaries. They can consider and propose solutions to the issues they've
investigated. Schools upstream of estuaries can do this as well looking at their watershed and
connection to coastal waters.
BACK TO TABLE OF CONTENTS
SECTION 6: ESTUARIES IN THE BALANCE
Page 62 of 103
Estuaries in the Balance
SECTION 6: ESTUARIES IN THE BALANCE
4. As individuals, small groups or as a class, use a two circle Venn diagram, brainstorm Human
Community Needs and Natural Community Needs with an overlapping portion of the circle
which has been labeled Shared Needs.
5. Have students compare and contrast how estuaries resources have been and are being used
looking at pre and post-European settlement cultures.
6. Have students identify behavior changes they would like to make to conserve water. Have
them quantify present water use in gallons and predict what they can save. Students can
journal their daily experience and present findings to the class.
7. Have students identify a service project that allows them to help on an estuary project, like
bagging oyster shells, or help upstream by helping conserving water—or protecting water
quality, for instance, by stenciling storm drains as reminders that storm water flows to the
Gulf.
BACK TO TABLE OF CONTENTS
SECTION 6: ESTUARIES IN THE BALANCE
Estuaries in the Balance
Page 63 of 103
GLOSSARY OF TERMS
Glossary of Terms
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Adapt(ed) - The process whereby an individual adjusts to changing conditions within its
habitat or a population, and becomes better suited to its habitat.
Adaptable - The ability for an individual or a population to become better suited to its
habitat.
Algae - Microscopic, single cell plants found in a variety of aquatic environments.
Angler(s) - A fisherman who uses the fishing technique of angling.
Angling - A method of fishing by means of an "angle" (fish hook). The hook is usually
attached to a fishing line and the line is often attached to a fishing rod. Angling is a principal
method of sport fishing, but commercial fisheries also use angling methods such as long
lining or trolling.
Aquatic - Relating to water; living in or near water, taking place in water.
Bacteria - A large domain of microorganisms. Typically a few micrometers in length,
bacteria are present in most habitats on the planet.
Barge(s) - A flat-bottomed boat, built mainly for river and canal transport of heavy goods
Barnacles - Related to crabs and lobsters. Barnacles are exclusively marine, and tend to live
in shallow and tidal waters. They are sessile (non-motile) suspension feeders, and have two
larval stages. Around 1,220 barnacle species are currently known.
Barrier island(s) - A coastal landform and a type of barrier system composed of relatively
narrow strips of sand that is parallel to the mainland coast. They usually occur in chains.
Bay(s) - A large, semi-enclosed body of water connected to an ocean through a tidal pass and
receiving fresh water from a river basin. A large bay may be called a gulf, a sea, a sound, or a
bight.
Biofilm - An aggregate of microorganisms in which cells adhere to each other on a surface.
Blue Crabs (Eastern blue crabs) - A species of crab native to the waters of the western
Atlantic Ocean, the Pacific coast of Central America and the Gulf of Mexico. The blue crab is
an important part of the estuarine food web, and of significant seafood value and economic
importance in the United States.
Brackish - Salty to slightly salty water, resulting from a mixture of fresh and seawater, such
as that found in estuaries.
Buoy(s) - A floating device that can have many purposes, including aid to navigation and
marking fishing nets and crab traps. It can be anchored (stationary) or allowed to drift with the
sea wave.
Captivity - Animals that live under human care are in captivity. Captivity can be used as a
generalizing term to describe the keeping of either domesticated animals (livestock and pets)
or wild animals.
Cargo(es) - Goods or produce transported, generally for commercial gain, by ship or aircraft.
Catch limits - Fishing restrictions put in place to protect species from being overfished.
Citizens - Citizenship denotes the link between a person and a state and is associated with the
right to work and live in a country and to participate in political life.
Climate - The statistics of temperature, humidity, atmospheric pressure, wind, precipitation,
atmospheric particle count and other meteorological elemental measurements in a given
region over long periods.
BACK TO TABLE OF CONTENTS
GLOSSARY OF TERMS
Estuaries in the Balance
Page 64 of 103
GLOSSARY OF TERMS
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Climate change - Changes in climate due to human activities that includes an overall increase
in world temperatures caused by additional.
Consumer(s) - Any organism that eats producers, or other consumers, as food
Contaminants - Impurities are substances inside a confined amount of liquid, gas, or solid,
which differ from the chemical composition of the material or compound.
Crab burrow(s) - A hole or tunnel dug into the ground by a crab to create a space suitable for
habitation and protection from predators.
Debris - Rubble, wreckage, ruins, litter and discarded garbage.
Decomposing - Decomposition (or rotting) is the process by which organic substances are
broken down into simpler forms of matter. The process is essential for recycling the finite
matter.
Delta - A river delta is a landform that is formed at the mouth of a river, where the river flows
into an ocean, sea, estuary, lake, or reservoir. Deltas are formed from the deposition of the
sediment carried by the river as the flow leaves the mouth of the river. Over long periods of
time, this deposition builds the characteristic geographic pattern of a river delta.
Desalination - Refers to any of several processes that remove some amount of salt and other
minerals from saline water. Salt water is desalinated to produce fresh water suitable for
human consumption or irrigation.
Disease - An abnormal condition affecting the body of an organism. It may be caused by
external factors, such as infectious disease, or it may be caused by internal dysfunctions, such
as autoimmune diseases.
Dredge(d)(ing) - Dredging is an excavation activity usually carried out at least partly
underwater with the purpose of gathering up bottom sediments and disposing of them at a
different location. This technique is often used to keep waterways navigable. Dredging is also
used as a technique for fishing for certain species of edible clams, oysters, and crabs.
Drought(s) - An extended period of months or years when a region receives consistently
below average precipitation. It can have a substantial impact on the ecosystem and agriculture
of the affected region. Even a short, intense drought can cause significant damage and harm
the local economy.
Ecological services - Humankind benefits from a multitude of resources and processes that
are supplied by natural ecosystems. Collectively, these benefits are known as ecosystem
services and include products like clean drinking water and processes such as the
decomposition of wastes.
Ecosystem(s) - A system formed by the interaction of a community of organisms with their
physical environment.
Endangered - An endangered species is a population of organisms which is facing a high risk
of becoming extinct because it is either few in numbers, or threatened by changing
environmental or predation parameters.
Erosion - Condition in which the earth's surface is worn away by the action of water and/or
wind.
Estuarine - Of or having to do with the area where the sea meets a freshwater stream/river.
An oyster is an estuarine animal.
Estuary(ies) - A partly enclosed coastal body of water with one or more rivers or streams
flowing into it, and with a free connection to the open sea. Estuaries are amongst the most
heavily populated areas throughout the world, with about 60% of the world’s population
BACK TO TABLE OF CONTENTS
GLOSSARY OF TERMS
Estuaries in the Balance
Page 65 of 103
GLOSSARY OF TERMS
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
living along estuaries and the coast. As a result, estuaries are suffering degradation by many
factors.
Evaporation - Liquid water becoming a gas.
Extinction - In biology and ecology, extinction is the end of an organism or of a group of
organisms, normally a species.
Fertilized - Fertilization is the fusion of gametes to produce a new organism. Depending on
the animal species, the process can occur within the body of the female in internal
fertilization, or outside (external fertilization). The entire process of development of new
individuals is called reproduction.
Filter (feeders) - Filter feeders are animals that feed by straining suspended matter and food
particles from water. Filter feeders can play an important role in clarifying water.
Fish stocking - The practice of raising fish in a hatchery and releasing them into a river, lake,
or the ocean to supplement existing populations, or to create a population where none exists.
Fishery - An entity engaged in raising or harvesting fish.
Flock(s) - A group of birds typically engaged in a similar behavior in flight, or while
foraging.
Fly (fishing) - Fly-fishing is an angling method in which an artificial "fly" is used to catch
fish. The fly is cast using a fly rod, reel, and specialized weighted line.
Fly rod - A fishing pole is a long, flexible length of fiberglass, carbon fiber, graphite or,
classically, bamboo, used to catch fish.
Food chain - A community of organisms representative of the eating relationships between
species where each member is eaten in turn by another member.
Foraging - Searching for and exploiting food resources. It affects an animal's fitness because
it plays an important role in an animal's ability to survive and reproduce.
Freshwater (fresh water) - Naturally occurring water on the Earth's surface in ice sheets, ice
caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in
aquifers and underground streams. Fresh water is generally characterized by having low
concentrations of dissolved salts and other total dissolved solids.
Freshwater inflows (flows) - Freshwater generally refers to water, which collects within a
river basin and flows downstream from the inland sources. This water enters into the bay and
mixes with the more saline seawater, creating an estuary area that is less salty than the ocean.
Fungus(i) - A member of a large group of organisms that includes microorganisms such as
yeasts and molds as well as the more familiar mushrooms.
Game fish - Fish pursued for sport by recreational anglers.
Habitat destruction - The process in which natural habitat is rendered functionally unable to
support the species present. In this process, the organisms that previously used the site are
displaced or destroyed, reducing biodiversity.
Habitat(s) - An area that provides food, water and/or shelter for a particular species of
animal, plant, or other type of organism.
Human footprint - The ecological footprint is a measure of human demand on the Earth's
ecosystems.
Industry(ies) - The production of an economic good or service within an economy.
Inlets - A narrow body of water leading inland from a larger body of water, often leading to
an enclosed body of water, such as a sound, bay, lagoon, or marsh. In seacoasts, an inlet
usually refers to the actual connection between a bay and the ocean.
BACK TO TABLE OF CONTENTS
GLOSSARY OF TERMS
Estuaries in the Balance
Page 66 of 103
GLOSSARY OF TERMS
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Intercoastal waterway - A 3,000-mile waterway along the Atlantic and Gulf coasts of the
United States. It provides a navigable route along its length without many of the hazards of
travel on the open sea.
Invertebrate(s) - Animal species that do not develop a vertebral column.
Jetties - A structure used in river, dock, and maritime works.
Juvenile(s) – An individual organism that has not yet reached its adult form, sexual maturity
or size. Juveniles sometimes look very different from the adult form.
Lagoon(s) - A shallow, elongated body of water separated from a larger body of water by
barrier islands or reefs.
Larva(l) - A distinct juvenile form that many animals undergo before metamorphosis into
adults. The larva's appearance is generally very different from the adult form. A larva often
has unique structures and organs that do not occur in the adult form. Larvae are frequently
adapted to environments separate from adults. Some species such as barnacles are immobile
as adults, and use their mobile larval form to distribute themselves.
Marine worms - Any worm that lives in a marine environment is considered a marine worm.
Marsh(es) or coastal marsh(es) - A type of wetland that is dominated by herbaceous rather
than woody plant species. Marshes often form a transition between the aquatic and terrestrial
ecosystems, are important nursery areas and highly productive.
Mated pair(s) - Breeding pair is a pair of animals, which cooperate over time to produce
offspring with some form of a bond between the individuals. For example, many birds mate
for a breeding season or sometimes for life. They may share some or all of the tasks involved:
building a nest, incubating the eggs and feeding and protecting the young.
Median - The median of a finite list of numbers can be found by arranging all the
observations from lowest value to highest value and picking the middle one. If there is an
even number of observations, then there is no single middle value; the median is then usually
defined to be the mean of the two middle values.
Megalopa(ae) or megalops - When blue crabs reach the megalopal stage of development
they become good swimmers. There is plenty of food and protection for them in sea grass
habitat and they prefer the higher salinity water found there.
Microorganisms - An organism of microscopic size, such as bacterium.
Microscopic - Something microscopic is too small to be seen by the naked eye, requiring a
lens or microscope to see them clearly.
Midden(s) – An old dump for domestic waste and other artifacts associated with past human
occupation.
Migration(s) - Bird migration is the regular annual seasonal journey undertaken by many
species of birds. Bird movements include those made in response to changes in food
availability, habitat, or weather.
Mollusks - A large group of invertebrate animals. Around 85,000 species are recognized.
Because mollusks have such a varied range of body structures, it is difficult to find defining
characteristics to apply to all modern groups. The two most universal features are a mantle
with a significant cavity used for breathing and excretion, and the structure of the nervous
system.
Molt(s) - Molting is the manner in which an animal routinely casts off a part of its body
(often but not always an outer layer or covering), either at specific times of year, or at specific
points in its life cycle.
BACK TO TABLE OF CONTENTS
GLOSSARY OF TERMS
Estuaries in the Balance
Page 67 of 103
GLOSSARY OF TERMS
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Mudflats (tidal) - Also known as tidal flats, are coastal wetlands that form when mud is
deposited by tides or rivers. They are found in sheltered areas such as bays, bayous, lagoons,
and estuaries.
Mussels - The common name used for members of several families of mollusks, from
saltwater and freshwater habitats. These groups have in common a shell whose outline is
elongated and asymmetrical compared with other edible clams, which are often more or less
rounded or oval.
Natural heritage - Heritage is that which is inherited from past generations, maintained in the
present and bestowed for the benefit of future generations. Natural heritage is the legacy of
natural objects and intangible attributes encompassing the countryside and natural
environment, including plants and animals or biodiversity.
Nesting season - The time of year during which birds and some other animals, particularly
some reptiles, build nests, lay eggs in them, and in most cases bring up their young. It is
usually in the spring.
Nurseries - In marine environments, a nursery habitat is a subset of all habitats where
juveniles of a species occur, having a greater level of productivity per unit area than other
habitats. Mangroves, salt marshes and sea grass are typical nursery habitats for a range of
marine species.
Nutrient(s) - A chemical that an organism needs to live and grow.
Organic material - Broken down remains of plants and animals in the environment.
Organisms - Any contiguous living system (such as animal, fungus, micro-organism, or
plant). In at least some form, all types of organisms are capable of response to stimuli,
reproduction, growth and development, and maintenance of homeostasis as a stable whole.
Overfishing - The act whereby fish stocks are depleted to unacceptable levels, regardless of
water body size. The ability of a fishery to recover from overfishing depends on whether the
ecosystem's conditions are suitable for the recovery.
Oxygen - A chemical element. It is an important part of the atmosphere and is necessary to
sustain most terrestrial life.
Oyster reef(s) - Reefs formed by oysters.
Oyster(s) (Eastern Oyster(s)) – A group of bivalve mollusks, which live in marine or
brackish habitats. Humans commonly consume some kinds of oyster as a delicacy. Other
kinds are harvested for the pearl produced within the mantle.
Parasite(s) - An animal or plant that lives in or on, and obtains nourishment from, another
animal or plant.
Peninsula - A piece of land that is bordered by water on three sides but connected to
mainland.
Photosynthesis - A process used by plants and other organisms to convert the light energy
captured from the sun into chemical energy that can be used to fuel the organism's activities.
Photosynthesis occurs in plants, algae, and many species of bacteria.
Phytoplankton - Photosynthesizing microscopic organisms that drift the upper sunlit layer of
almost all oceans and bodies of fresh water. They are agents for "primary production" and
account for half of all photosynthetic activity on Earth.
Plankton - Any organisms (animal, plant, bacteria, etc.) that drift in the water column and are
incapable of swimming against a current. They provide a crucial source of food to many large
aquatic organisms, such as fish and whales.
BACK TO TABLE OF CONTENTS
GLOSSARY OF TERMS
Estuaries in the Balance
Page 68 of 103
GLOSSARY OF TERMS
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Pollutant(s) - Harmful substances introduced to air, soil, or water.
Population - All the organisms that both belong to the same group or species and live in the
same geographical area.
ppt - Parts per thousand.
Prairie - Grassland ecosystems found in temperate climates with moderate rainfall. A
composition of grasses, herbs, and shrubs, rather than trees, is the dominant vegetation type.
Producers - An organism that produces food from by using energy from light (by
photosynthesis) or inorganic chemical reactions.
Protein - Large biological molecules consisting of one or more chains of amino acids.
Proteins perform a vast array of functions within living organisms.
Range(s) - In a set of data, the range is the difference between the largest and smallest values.
Redfish (or Red Drum) - An economically important game fish that is found in the Atlantic
Ocean from Massachusetts to Florida and in the Gulf of Mexico from Florida to Northern
Mexico.
Reintroduced - Reintroduction is the deliberate release of a species into the wild, from
captivity or relocated from other areas where the species survives. A species that needs
reintroduction is usually one whose existence has become threatened or endangered in the
wild.
Reservoir(s) - An artificial lake or impoundment from a dam used to store water.
River basins - An extent or an area of land where surface water from rain and melting snow
or ice converges to a single point, usually the exit of the basin, where the waters join another
water body, such as a river, lake, reservoir, estuary, wetland, sea, or ocean.
Saline - Saline water is a general term for water that contains a significant concentration of
dissolved salts.
Salinity(ies) - The saltiness or dissolved salt concentration in water or within coastal soil.
Sea cucumbers - Marine invertebrates with a leathery skin and an elongated body. Sea
cucumbers are found on the sea floor worldwide.
Seagrass meadow(s) or bed(s) - Highly diverse and productive ecosystems that are nursery
grounds for many marine species.
Seagrass(es) - Flowering plants, which grow in marine environments.
Seawater (salt water) - Water from a sea or ocean.
Shellfish - A culinary and fisheries term for aquatic invertebrates used as food. Although
most kinds of shellfish are harvested from saltwater environments, some kinds are found only
in freshwater.
Snails - The common name "snail" is applied to most mollusks that have a coiled shell large
enough for the animal to retract completely into. It includes not just land snails but also
thousands of species of sea snails and freshwater snails.
Spat - Attached oyster larvae are called spat. Spat are oysters less than 1 inch long.
Spawning season - Spawning is the process of releasing the eggs and sperm. Spawning often
happens during a particular annual season.
Sportfish - Fish pursued for sport by recreational anglers. They can be freshwater or marine
fish.
Submerged - Being entirely underwater.
Surfcasting - Surf fishing from the beach by casting into the surf at or near the shoreline.
BACK TO TABLE OF CONTENTS
GLOSSARY OF TERMS
Estuaries in the Balance
Page 69 of 103
GLOSSARY OF TERMS
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Swim bladders - An internal gas-filled organ that contributes to the ability of a fish to control
its buoyancy, and thus to stay at the current water depth without having to waste energy in
swimming.
Tarpon - Large fish of the genus Megalops.
Territory - An area that an animal of a particular species consistently defends against others.
Animals that defend territories in this way are referred to as territorial.
Tidal ponds - Pools of seawater created when the tide recedes.
Tide(s) - The rise and fall of sea levels caused by the combined effects of the gravitational
forces exerted by the Moon and the Sun and the rotation of the Earth.
Unison call(s) - A call made by pair-bonded cranes. It gets its name because both the male
and female call in unison with each other.
Water column - A conceptual column of water from surface to bottom sediments.
Water conservation - Planned management of water resources to prevent exploitation,
destruction or neglect.
Water quality - The chemical, physical and biological characteristics of water. The most
common standards used to assess water quality relate to health of ecosystems, safety of
human contact and drinking water.
Water recycling - Wastewater cleaned for re-use, usually for non-potable purposes such as
irrigating landscape and refilling aquifers.
Waterfowl - Birds, which includes ducks, geese, and swans.
Watershed(s) - An area of land that drains to a lake, stream or other body of water.
Wetlands - An area of land whose soil is saturated with moisture either permanently or
seasonally.
Windpipe - A tube that connects the pharynx and larynx to the lungs, allowing the passage of
air.
Wingspan - The distance from one wingtip to the other wingtip.
Zooplankton - Animals (or organisms that eat other organisms) that drift in the water column
and are incapable of swimming against a current. Individual zooplankton are usually too
small to be seen with the naked eye, but some, such as jellyfish, are large.
BACK TO TABLE OF CONTENTS
GLOSSARY OF TERMS
Page 70 of 103
Estuaries in the Balance
APPENDIX A: TEKS CORRELATIONS
Appendix A
Texas Essential Knowledge and Skills (TEKS)
Correlations (by grade)
Grade 4
§113.15. Social Studies, Grade 4
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
History
Blue Crabs in Mix
Oyster Reef Builder
Redfish Angler
Whooper’s Tale
Estuaries in Balance
1. b, d
(extension
activity
Grade 4
6. a, b
(extension
activity)
7. a
9. b, c
6. b
9. a, b, c
9. b, c
9. c
7. a
9. a, b, c
Economics
Social
studies
skills
12. a, b
12. a, b
13. b
12. a, b
13. b
§112.15. Science, Grade 4
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
Geography
Science,
technology,
and society
Scientific
Investigation
and reasoning
Blue Crabs in Mix
Oyster Reef Builder
Redfish Angler
Whooper’s Tale
Estuaries in Balance
BACK TO TABLE OF CONTENTS
Matter
and
energy
Force,
motion,
and
energy
Earth
and
space
Organisms and
environments
10. a
9. b
10. a, c
10. a, c
10. a, c
9. b
10. a, c
9. a, b
APPENDIX A: TEKS CORRELATIONS
Page 71 of 103
Estuaries in the Balance
APPENDIX A: TEKS CORRELATIONS
Grade 5
§113.16. Social Studies, Grade 5
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
History
Geography
6. a, b
(extension
activity)
9. b
6. b
9. b
9. b
9. b
8. b
9. b
Blue Crabs in Mix
Oyster Reef Builder
Redfish Angler
Whooper’s Tale
Estuaries in Balance
Grade 5
Social
studies
skills
13. b
13. b
13. b
§112.16. Science, Grade 5
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
Economics
Science,
technology,
and society
Scientific
Investigation
and reasoning
Blue Crabs in Mix
Oyster Reef Builder
Redfish Angler
Whooper’s Tale
Estuaries in Balance
BACK TO TABLE OF CONTENTS
Matter
and
energy
Force,
motion,
and
energy
Earth
and
space
Organisms and
environments
9. c
9. a
10. a
9. a, c
10. a
9. a
10. a
9. a, c
10. a
9. c
APPENDIX A: TEKS CORRELATIONS
Page 72 of 103
Estuaries in the Balance
APPENDIX A: TEKS CORRELATIONS
Grade 6
§113.18. Social Studies, Grade 6
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
History
Science,
Social
technology, studies
skills
Geography Economics and society
3. a
5. a
6. b
Blue Crabs in Mix
Oyster Reef Builder
Redfish Angler
Whooper’s Tale
Estuaries in Balance
Grade 6
8. a, b
3. a
5. a
6. b
8. a, b
§112.18. Science, Grade 6
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
3. a
5. a
7. b
Scientific
Investigation
and reasoning
Blue Crabs in Mix
Oyster Reef Builder
Redfish Angler
Whooper’s Tale
Estuaries in Balance
BACK TO TABLE OF CONTENTS
Matter
and
energy
Force,
motion,
and
energy
Earth
and
space
Organisms
and environments
12. e, f
12. e, f
12. e, f
12. e, f
12. e, f
12. e, f
APPENDIX A: TEKS CORRELATIONS
Page 73 of 103
Estuaries in the Balance
APPENDIX A: TEKS CORRELATIONS
Grade 7
§113.19. Social Studies, Grade 7
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
History
Science,
Social
technology, studies
skills
Geography Economics and society
9. b
Blue Crabs in Mix
2. a
(extension
activity)
Oyster Reef Builder
Redfish Angler
Whooper’s Tale
Estuaries in Balance
10. a
9. b
10. a
Grade 7
20. d
§112.19. Science, Grade 7
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
13. a
Scientific
Investigation
and reasoning
Blue Crabs in Mix
Matter
and
energy
Force,
motion,
and
energy
5. c
Earth
and
space
8. a
Oyster Reef Builder
Redfish Angler
8. a
Whooper’s Tale
Estuaries in Balance
BACK TO TABLE OF CONTENTS
5. c
5. c
7. b
8. a
8. a, c
Organisms and
environments
10. b
10. b
11. b
10. b
10. b
11. b
10. b
11. b
13. a
10. b
APPENDIX A: TEKS CORRELATIONS
Page 74 of 103
Estuaries in the Balance
APPENDIX A: TEKS CORRELATIONS
Grade 8
§113.20. Social Studies, Grade 8
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
History
Science,
Social
technology, studies
skills
Geography Economics and society
Blue Crabs in Mix
Oyster Reef Builder
Redfish Angler
Whooper’s Tale
Estuaries in Balance
11. b
11. b
Grade 8
§112.20. Science, Grade 8
Content Area
Strand
Estuaries in Balance Module
Estuary Introduction
Scientific
Investigation
and reasoning
Blue Crabs in Mix
Oyster Reef Builder
Redfish Angler
Whooper’s Tale
Estuaries in Balance
BACK TO TABLE OF CONTENTS
Matter
and
energy
Force,
motion,
and
energy
Earth
and
space
Organisms
and environments
11. b, c, d
11. a, b, c
11. b, c, d
11. b, c, d
11. a, b, c, d
11. b, c, d
APPENDIX A: TEKS CORRELATIONS
Page 75 of 103
Estuaries in the Balance
APPENDIX B: HANDHELD TECHNOLOGIES
Appendix B
Using Handheld Technologies in Field Experiences
Introduction
Recent advances in hand-held digital technologies open new possibilities for teachers and students on
field trips and other projects outside and within the classroom. At the same time, planning the use of
these technologies is important so that they enhance and complement the recognized power of direct
experience with natural and social environments.
The recommended approaches in this section of the Estuaries in the Balance teachers’ guide are
informed by research into evolving best practices in this burgeoning field of digitally enhanced
learning. They also take into account the experience of faculty and teachers engaged with CGEE’s
professional development and learning programs. Our approach has been to identify strategies that
make use of inherent capabilities of hand-held digital devices and commonly available apps.
In general, we recommend using the Estuaries in the Balance and similar multimedia learning
programs as pre- and post-field learning resources that provide context for field experiences and help
interpret their significance, rather than using these programs in the field. We believe that being out of
doors, in urban or natural environments, provides its own rich learning context, and that use of digital
technologies shouldn’t create barriers to interfere with the power of these experiences.
Sampling of Currently Available Hand-Held Digital Devices
Apple Devices (iPhone, iPad, iPod)
A large amount of the research and best practices that have been published regarding technology and
field experiences has been utilizing Apple technology. Overall, the vast majority of the buzz around
using technology with field experiences has been utilizing Apple technology, which means that there
are more articles, K-12 teacher testimonials, and best-practices than any other product line.
iPhone 4S (older generations of the iPhone are no longer sold)
 Price: $199-$299 (with contract); $649-$749 (without contract)
 Stock capabilities: Siri; GPS location (with 3G coverage); 14 megapixel camera
 3G Coverage: Can be used with any cellphone date provider or with a joint MyFi network
(maximum of 4 phones per MyFi network recommended)
iPod Touch
 Price: $199-$399
 Stock capabilities: Text messaging capability; GPS location (with 3G coverage); 14
megapixel camera; app capabilities; iCloud coverage.
 3G Coverage: Can be used with any cellphone date provider or with a joint MyFi network
(maximum of 4 phones per MyFi network recommended)
BACK TO TABLE OF CONTENTS
APPENDIX B: HANDHELD TECHNOLOGIES
Page 76 of 103
Estuaries in the Balance
APPENDIX B: HANDHELD TECHNOLOGIES
iPad 3 (older generations of the iPad are no longer sold)
 Price: $499-$899
 Stock capabilities: Web browsing and Safari; GPS location (with 3G coverage); 14 megapixel
camera; app capabilities; iCloud coverage.
 3G Coverage: Can be used with any cellphone date provider or with a joint MyFi network
(maximum of 4 phones per MyFi network recommended)
Android Tablets
The primary competitor to the aforementioned Apple products are Android-based devices. Overall
they have very similar functionality to the Apple devices with supposed benefit of operating with
Google natively. During my research and interviews with various educational technology
professionals, nearly every single one of them recommended Apple products over their Android
counterparts because of the unparalleled educational support (not only corporate, but also forums,
Apple Distinguished Educators, and extensive research done on them). Nonetheless, Android
products are certainly worthy of consideration.
LG Lucid 4G (similar functionality to the iPhone 4S)
 Price: $129-$209 (with contract); $549-$799 (without contract)
 Stock capabilities: Google-based Android OS which natively runs all Google apps and
programs; GPS location (with 3G coverage); 14 megapixel camera
 3G Coverage: Can be used with any cellphone date provider or with a joint MyFi network
(maximum of 2 phones per MyFi network recommended)
Pantech Pocket (similar functionality to the iPod Touch)
 Price: $199-$299
 Stock capabilities: 4G capability, GPS location via Google Maps, 5 megapixel camera, wide
profile virtual keyboard, 3.5 inch touch-screen.
 3G Coverage: Can be used with any cellphone date provider or with a joint MyFi network
(maximum of 1 phones per MyFi network recommended)
Asus Transformer Prime (similar functionality to the iPad 3)
 Price: $429-$799
 Stock capabilities: New Google-based Android “Gingerbread” OS; GPS location (with 3G
coverage); 14 megapixel camera; 1280x768 screen; app capabilities; cloud syncing apps
available.
 3G Coverage: Can be used with any cellphone date provider or with a joint MyFi network
(maximum of 1 device per MyFi network recommended; even then, research shows this will
be fairly slow)
NOTE: These three devices were chosen to give an idea of what Android alternatives exist to Apple
products on a similar level of price/functionality. For a full listing of Andoid-capable devices, visit
http://www.androidcentral.com/devices.
Intel Studybook
In 2011, Intel entered the educational tablet market with the Studybook, a 7″ tablet that is targeted to
young students (4-8 years old) with the goal of making their study more interactive, and more
efficient. The tablet format is a departure from the previous clamshell Netbook approach taken by
BACK TO TABLE OF CONTENTS
APPENDIX B: HANDHELD TECHNOLOGIES
Page 77 of 103
Estuaries in the Balance
APPENDIX B: HANDHELD TECHNOLOGIES
Intel. The Studybook is built as a small and rugged tablet designed to resist small spills and drops
(70cm). Its body is made of molded plastic which forms a single block with rounded corners (Nokia
uses a similar technique with their Lumia 800 and 900 phones). The electronics and the display are
mounted on a shock-absorbing platform that makes the tablet even more durable. The ports are
covered to avoid dust and liquids, and among them, there is a full-size USB port, that is very handy to
connect an array of sensors.
 Price: $99-$249
 Stock capabilities: Mobile Intel Atom processor; 7-inch (1024 x 860) screen; operating
system limited to educational apps installed by administrator; 5 megapixel camera; Wi-Fi
optional: accelerometer, light sensor, 3G and GPS capability, attachable microscope and
other scientific devices.
 3G Coverage: No native 3G functionality; can be upgraded for additional cost. Unknown
what the MyFi limit is for devices.
CURRICULUM IDEATION
NOTE: As of Spring of 2012, there are very few established, peer-reviewed, or generally wellarticulated curriculum models for using technology to facilitate field experiences in an environmental
education setting. This appears to be largely because most of these technologies are less than a year
old. In general, it appears that while schools are quick to incorporate new technologies into their
classrooms, there is a significant lag time between then and when they begin producing researched,
peer-reviewed models and discussions into what has and hasn't worked. The following research
consists of assorted insights, ideation, and predictions that might be applicable to the Harte Research
Center.
1. CHALLENGE/PROJECT-BASED PROJECT: Challenge Based Learning (CBL) is an engaging
multidisciplinary approach to teaching and learning that encourages students to leverage the
technology they use in their daily lives to solve real-world problems. Challenge Based Learning is
collaborative and hands-on, asking students to work with other students, their teachers, and
experts in their communities and around the world to develop deeper knowledge of the subjects
students are studying, accept and solve challenges, take action, share their experience, and enter
into a global discussion about important issues. For more info, visit the New Media Consortium
website and video at: http://www.nmc.org/projects/challenge-based-learning and
http://player.vimeo.com/video/23582085
• BEFORE TRIP: Within each group, assign various roles to allow role-playing,
collaboration, and a variety of lenses.
• BEFORE TRIP: Have each student develop their own “guiding question” or “research
query” which will form the impetus for their investigation and design their own avenue of
investigation of experiment to conduct at the site. (i.e., documenting species with camera,
taking soil samples, recording video interview with experts, etc). Have students create
Prezi presentation to show to class.
• BEFORE TRIP: Create online network (Facebook group, Google+ account, etc.) for 24/7
collaboration and assign posts of content, evolving hypotheses, discussions, etc.
• BEFORE TRIP: (Optional) Have students network with at least one expert in the field
(perhaps a pre-selected staff member from Harte) to learn more background on the topic
and further refine their guiding question/planned experiment.
BACK TO TABLE OF CONTENTS
APPENDIX B: HANDHELD TECHNOLOGIES
Page 78 of 103
Estuaries in the Balance
APPENDIX B: HANDHELD TECHNOLOGIES
•
•
DURING TRIP: Carry out experiment. Should require some sort of media capture to make
presentation.
Teacher strongly advised to make chart/diagram, which demonstrates how the different
role-playing tasks/lenses all contributed to a positive change.
2. FLICKR STREAM W/GPS FUNCTIONALITY: Send students out into the field with any of the
aforementioned camera and 3G-capable devices to photograph various species, landmarks,
geological formations, or locales. If the teacher wants to mark specific assigned areas for specific
groups, then can do this with a custom Google Maps chart. For instance, the teacher could assign
groups to take photos of areas that make up points on a grid on in a larger area in order to map the
local range/extent of a specific species. These photos can be uploaded to a Flickr stream and can
be tagged with GPS locations by the uploaders for review and analysis later in the classroom.
3. VIDEO-BLOGGING ON OBSERVATIONS: In order to not only expedite the recording of data
but also allow students to create their own unique narrative voice, the learners can use any
camera-equipped device (preferably one with front-facing auxiliary camera) to record their
observations in video-blog style entries. These can be paired with apps such as Fuse or Camtasial
to immediately send these videos to the cloud, which can be compiled by a waiting teacher or by
the class itself upon return.
4. INCORPORATE EXPERTS WHO ALSO HAVE DEVICES: One very important educational
opportunity that the field experience model offers is the ability to network with and learn from
experts or scientists. These individuals could be stationed in the field, at a base camp area, or
could be called upon for help or questions at a moment's notice. The iPhone 4S' “Facetime”
feature in particular would be very helpful for this component, as it would allow students to
remotely engage with the experts and use their cameras to direct their queries to specific objects
or areas.
5. UTILIZE PRE-LOADED MULTIMEDIA AT VARIOUS WAYPOINTS: If students are
embarking on a GPS-directed hike across a certain area (as proposed above) they can be notified
at various stops or waypoints to play a certain piece of multimedia that has already been loaded
onto their device (or they could also stream it as well). This could give them additional
information as to where they are at the moment, the species that are nearby, or even prompt them
for an assignment.
6. COOPERATIVE CLOUD-SHARING PROJECTS: This is a model that can be used as a standalone or in conjunction with any of the aforementioned ideas. Different groups of students can be
assigned different projects, observational goals, or research questions which can be combined into
a central document or folder using live synchronization to the cloud. This is particularly important
of the nature of these different projects are dependent on each other for constant updates.
BACK TO TABLE OF CONTENTS
APPENDIX B: HANDHELD TECHNOLOGIES
Page 79 of 103
Estuaries in the Balance
APPENDIX C: COASTAL BEND MAP
Appendix C
Coastal Bend Place-Name Map
(Back to Section 1: Estuary Intro - Background Info)
BACK TO TABLE OF CONTENTS
APPENDIX C: COASTAL BEND MAP
Page 80 of 103
Estuaries in the Balance
APPENDIX C: COASTAL BEND MAP
Coastal Bend Place-Name Map Quiz
BACK TO TABLE OF CONTENTS
APPENDIX C: COASTAL BEND MAP
Page 81 of 103
Estuaries in the Balance
APPENDIX D: PRE/POST TEST
Appendix D
Pre/Post Test
Estuary Introduction Video
1.) Check the two characteristics listed below that best describe an estuary.
__ a) fresh water mixes with salt water
__ b) constant salinity of 35ppt (35 grams of salt per liter of water)
__ c) protected from the open sea
2.) Order the following estuary terms describing water from freshest (1) to saltiest (3)
__ a) freshwater
__ b) ocean water
__ c) brackish water
3.) Check four natural factors that most influence the salinity of estuary water.
__ a) rainfall
__ b) wind
__ c) altitude
__ d) freshwater inflow
__ e) curve of the coastline
4.) ___True or___False: Freshwater inflow to estuaries is often influenced by human activities
upstream.
5.) ___True or ___False: Texas rainfall increases as you travel from southwest to northeast. More
rainfall often increases freshwater inflow.
6.) Check two of the results of reducing freshwater that flows to an estuary.
__ a) fish are more active
__ b) estuary salinity (the saltiness of the water) goes up
__ c) fewer nutrients flow into the estuary
7.) Check the names four species most likely to live in an estuary.
__ a) Red Snapper
__ b) Blue Crabs
__ c) Redfish
__ d) Oysters
__ e) Whooping Cranes
8.) ___True or___False: Blue crabs have adapted to the constant high salinity in estuaries by staying
near the saltier Gulf waters for most stages of their lifecycle.
BACK TO TABLE OF CONTENTS
APPENDIX D: PRE/POST TEST
Page 82 of 103
Estuaries in the Balance
APPENDIX D: PRE/POST TEST
Pre/Post Test (continued)
Blue Crabs In the Mix Sub-module
1.) Check four habitats below that you're likely to find in or near an estuary
__ a) coastal marsh
__ b) boreal forest
__ c) seagrass bed
__ d) oyster reef
__ e) open water
2.) Choose the 3 estuary species and label them: (1) for producer, (2) primary consumer (3)
secondary consumer.
__ a) passenger pigeon
__ b) zooplankton
__ c) phytoplankton
__ d) redfish
3.) ___True or ___False: Blue crabs have adapted to oyster reef habitat by secreting a chemical that
causes oysters to open their shells.
4.) ___True or ___False: When measuring salinity, scientists use the short initials, "ppt" to mean
"parts per ten"
5.) High salinity can harm blue crabs. Check two of them that are listed below.
__ a) increase the chance of certain diseases
__ b) some parasites that attack blue crabs thrive in higher salinity
__ c) high salinity affects their eyesight and crabs can no longer find food
6.) Number four of the lifecycle stages of the blue crab, 1 through 4, in the order they occur. Leave
the incorrect answer below blank
__ a) zoea
__ b) juvenile
__ c) megalopa
__ d) fledgling
__ e) adult
7.) ___True or ___False: Food and protection are services that a habitat provides for the creatures
that live there.
8.)___True or ___False: Pulses of freshwater inflow to estuaries tends to increase the "ppt" or
salinity values in estuary water.
9.) Identify a blue crab behavior that is not true.
__ a) female blue crabs release eggs close to the high salinity Gulf waters
__ b) blue crab females release eggs nearer freshwater where rivers enter a bay.
BACK TO TABLE OF CONTENTS
APPENDIX D: PRE/POST TEST
Page 83 of 103
Estuaries in the Balance
APPENDIX D: PRE/POST TEST
Pre/Post Test (continued)
Oyster Reef Builder
1.) Number the lifecycle stages of the Eastern Oyster, 1 to 5 in the order they occur.
__ a) spat
__ b) adult
__ c) pediveliger
__ d) egg
__ e) larva
2.) Check the answer that best describes the structure of oyster reefs.
__ a) Oyster reefs have smooth surfaces that helps algea grow that fish like best.
__ b) Oyster reefs have irregular surfaces where small creatures can easily hide
3.) Check the answer that best describes what oyster reefs provide estuary creatures.
__ a) irregular structure and food
__ b) open water and protection
4.) Check the answer that best describes a species that inhabits the oyster reef
__ a) Whooping cranes grab oysters and drop them from the air to break the shells
__ b) the Atlantic Croaker hunts young blue crabs hiding in the reef structure
5.) Pick the three reasons listed below that best describe why oyster reefs are declining.
__ a) poor water quality due to pollution
__ b) young spat stage oysters have adapted to the water column habitat
__ c) habitat destruction due to coastal development and dredging
__ d) diseases and predators associated with high salinity
6.) Pick the answer that is not an optimal condition for oyster reef habitats.
__ a) larval oysters are present
__ b) water quality is good
__ c) good currents and tides
__ d) salinity is high
__ e) disease levels are low
7.) ___True or ___False: Freshwater inflow to bays lowers salinity. Oysters prefer very low salinity
ranges.
8) ___True or ___False: Oyster harvesting is a good example of the Recreational sector of the Texas
Coastal Bend economy because people like to catch oysters.
9) ___True or ___False: Scientists in Copano Bay who re-build oyster reefs mimic the structure of
natural reefs by building one large reef that is not very tall.
BACK TO TABLE OF CONTENTS
APPENDIX D: PRE/POST TEST
Page 84 of 103
Estuaries in the Balance
APPENDIX D: PRE/POST TEST
Pre/Post Test (continued)
Redfish Angler
1.) ___True or ___False: The Nueces River is the main source of freshwater for Corpus Christi Bay.
2.) Which of the following is not part of the Corpus Christi Bay estuary system.
__ a) Nueces Bay
__ b) Aransas Bay
__ c) Redfish Bay
__ d) Nueces River
3.) Order the stages in the lifecycle of the Redfish, 1 to 4 beginning with the first stage.
__ a) adult
__ b) egg
__ c) larval
__ d) juvenile
4.) ___True or ___False: Redfish begin and end their lives in Gulf waters.
5.) ___True or ___False: Juvenile Redfish prefer open water where food is plentiful.
6.) ___True or ___False: Laval Redfish count on tides and currents to move them from passes to the
Gulf into quieter estuary bays.
7.) ___True or ___False: Shallow bays are dangerous places for juvenile Redfish because they don't
provide food or protection.
8.) Check two reasons for the historic decline of Redfish along the Texas Coastal Bend.
__ a) sport fishermen who exceed catch limits
__ b) commercial fishermen who netted too many fish
__ c) destruction of habitat where Redfish like to look for food
9.) Check three reasons why Redfish are now doing very well along the Texas Coastal Bend.
__ a) Fish hatcheries raise and release lots of Redfish into the estuary
__ b) Limiting the number of Redfish you can keep
__ c) Restoring habitat by removing seagrass that grows in the shallow bays
__ d) Better enforcement of fishing rules and regulations
BACK TO TABLE OF CONTENTS
APPENDIX D: PRE/POST TEST
Page 85 of 103
Estuaries in the Balance
APPENDIX D: PRE/POST TEST
Pre/Post Test (continued)
Whooper’s Tale
1.) Check the most important food source for whooping cranes when they are in Texas.
__ a) Acorns
__ b) Blue Crabs
__ c) Snails
__ d) Oysters
__ e) Wolf Berries
2.) ___True or ___False: The whooping cranes that winter in Texas are the last remaining naturally
occuring population in the world.
3.) Where do the whooping cranes that winter in Texas breed? Check all that apply:
__ a) Wisconsin
__ b) Canada
__ c) Texas
__ d) Florida
__ e) Louisianna
4.) Check the top two threats that lead to the near extinction of the whooping crane in the 1940s.
__ a) Unstustainable hunting
__ c) Wetland loss
__ d) Powerlines
__ e) Poor genetics leading to poor health and breeding success
__ f) Pollution and disease
5.) At its lowest population size, how many breeding pairs of whooping cranes remained?
__ a) 197
__ c) 21
__ d) 8
6.) ___True or ___False: Whooping cranes need to eat a lot of nutrious foods while in Texas?
7.) ___True or ___False: As more fresh water enters the estuary salinity levels increase.
8.) ___True or ___False: Whooping cranes find a lot more blue crabs to eat when salinities are high.
9.) What threatens the survival of the last remaining flock of whooping cranes? Check all that apply.
__ a) Illegal hunting
__ b) Pollution and disease outbreak
__ c) High salinities and low food availbity in their winter habitat
__ d) Poor genetic diversity
__ e) Wetland loss along their migration route
BACK TO TABLE OF CONTENTS
APPENDIX D: PRE/POST TEST
Page 86 of 103
Estuaries in the Balance
APPENDIX D: PRE/POST TEST
Pre/Post Test (continued)
Estuaries in the Balance Video
1.) Check the one service or resource that an estuary does not provide.
__ a) shoreline erosion protection
__ b) hurricane protection for towns and cities
__ c) popular deep-water seafood like grouper and red snapper
__ d) cleans polluted water
__ e) plentiful shellfish like oysters
__ d) recreation and tourist dollars
2.) ___True or ___False: Reducing freshwater inflow reduces salinity and that's good for estuaries.
3.) ___True or ___False: Dredging removes old shells and debris allowing new oyster reefs to form.
4.) ___True or ___False: Water pollution in the river is thoroughly cleaned by oysters through filter
feeding and is no longer a problem.
5.) ___True or ___False: Rising sea level is a myth and coastal habitats are not at risk.
6.) ___True or ___False: Development on the coast has destroyed lots of wetland habitat.
7.) Check the water-related behaviors or strategies that benefit Texas Coastal Bend estuaries.
__ a) people conserving water in upstream and in coastal communities.
__ b) de-salinization- a process that removes the salt from ocean water and brackish water to
make it fresh enough to drink.
__ c) reducing freshwater inflow to estuaries by diverting more water upstream
__ d) releasing water from dams to mimic natural pulses of freshwater inflow to estuaries
8.) Check the water-related behaviors or strategies do not benefit Texas Coastal Bend estuaries.
__ a) storing water freshwater underground in aquifers to reduce evaporation
__ b) capturing and recycling water that's been used once so it can be reused again.
__ c) purchasing appliances that are rated to use high volumes of water
__ d) allowing more phosphorus to enter upstream rivers so that estuary phytoplankton can
bloom more often.
BACK TO TABLE OF CONTENTS
APPENDIX D: PRE/POST TEST
Page 87 of 103
Estuaries in the Balance
APPENDIX D: PRE/POST TEST
Pre/Post Test Teacher Key
Estuary Introduction
Video
1.) a, c
2.) a -1, b - 3, c - 2
3.) a, b, d, e
4.) True
5.) True
6.) b, c
7.) b, c, d, e, f
8.) False
Blue Crabs in the Mix
Sub-module
1.) True
2.) b
3.) a-4, b-1, c-2, d-3
4.) True
5.) False
6.)True
7.) False
8.) b, c
9.) a, b, d
1.) a-4, b-5, c-3, d-1, e-2
2.) b
3.) a
4.) b
5.) a, c, d
6.) d
7.) False
8.) False
9.) False
1.) a, c, d, e
2.) b - 2, c - 1, d - 3
3.) False
4.) False
5.) a, b
6.) a-1, b-3, c-2, e-4
7.) True
8.) False
9.) b
Redfish Angler
A Whooper's Tale
1.) b
2.) True
3.) b
4.) a, b
5.) d
6.) True
7.) False
8.) False
9.) a, b, c, d, e, (all)
BACK TO TABLE OF CONTENTS
Oyster Reef Builder
Estuaries in the
Balance Video
1.) c
2.) False
3.) False
4.) False
5.) False
6.) True
7.) a, b, d
8.) c, d
APPENDIX D: PRE/POST TEST
Page 88 of 103
Estuaries in the Balance
APPENDIX E: STUDIO SCRIPTS
Appendix E
Narration Scripts for Six Program Videos
Estuary Introduction
(Back to Section 1: Estuary Intro - Keys to Success)
Along the edge of each continent where rivers large and small empty into the sea something happens
that is as simple as it is profound. Freshwater mixes with saltwater. When this happens in a place
that is protected from the open ocean, for example a bay that's partially enclosed by a peninsula or a
string of islands, then the stage is set for one of nature’s most amazing life systems, known as an
estuary. Nicknamed the cradles of the sea, estuaries provide spawning and nursery grounds for fish
and shellfish around the world. In the Gulf of Mexico, that includes 90-percent of the species people
enjoy as seafood.
Estuaries are so important for nurturing marine life because they provide rich conditions only found
in the transition zone between fresh water and ocean environments. Estuaries are generally less
saline, or salty, than the sea. The salinity of ocean water averages 35 parts per thousand while the socalled brackish water typical of estuaries ranges between point 5 and 30 parts per thousand (ppt).
But averages don't tell the whole story because conditions in an estuary are constantly changing.
Water levels rise and fall with the tides. Salinity can vary with rainfall, rates of evaporation, a curve
in the coastline or the path of the wind. Most importantly, an estuary’s salinity, and its health, are
strongly related to the quality and quantity of freshwater inflows from rivers and streams, both of
which are affected by how people use water upstream.
Few places in the world can match the tremendous range of salinity that is found in estuaries along
the Texas Gulf coast. The amounts of freshwater flowing into Texas estuaries varies from north to
south, and is strong related to how much rain occurs across the state. Like the rest of east Texas,
along the northeastern coast, rainfall averages more than 50 inches per year. The southwestern coast
averages less than 30 inches per year, and even less during droughts. In the north, greater freshwater
inflows result in lower salinities, while in the south, less freshwater makes for higher salinities.
Estuaries in the middle—in the Coastal Bend—are some of the richest in estuary
life, but they’re also the most vulnerable. Here, where climate is balanced between wet and dry,
human impacts are especially important. If people use so much freshwater that amounts flowing into
to the estuary are significantly reduced—especially in times of drought—salinity levels can get so
high that life in the estuary is at risk. With a rising human population, managing water to assure
there’s enough reaching the estuaries is challenging today and will be even more so in the years
ahead.
Productivity in an estuary changes with the seasons and differences in the amount of organic
material that the river carries from its watershed. In a healthy estuary, these complex changes follow
patterns that are repeated over time. Usually spring and fall bring the most nutrients, as freshwater
flows are greatest. Lower freshwater inflows in summer and winter bring less nutrients. The estuary’s
living creatures have adapted in different ways to these dynamic patterns.
BACK TO TABLE OF CONTENTS
APPENDIX E: STUDIO SCRIPTS
Estuaries in the Balance
Page 89 of 103
APPENDIX E: STUDIO SCRIPTS
Oysters live their whole lives on and around reefs where salinity levels average 10-20 parts per
thousand. Blue crabs release their fertilized eggs in saline waters close to Gulf inlets, and then move
throughout the estuary during their many life stages. Redfish spend their early years in the estuary
and return to the Gulf as mature adults. The flock of whooping cranes that migrate from Canada to
spend the winter in the San Antonio Bay area rely heavily on coastal marshes during this critically
important part of their annual cycle.
Life in an estuary is as varied as it is interconnected. Humans are part of this unique web of life, and
to maintain healthy estuaries, we must take care to rock gently this "cradle of the seas".
(Back to Section 1: Estuary Intro - Keys to Success)
Salinity and Blue Crabs
(Back to Section 2: Blue Crabs - Keys to Success)
Have you ever been really, really cold—teeth chattering and shivering from head to toe? How about
when it’s so hot outside you can’t move a muscle without breaking a heavy sweat? Well, plants and
animals adapted to estuary life tolerate their own extremes—of salinity, or saltiness—in the water
surrounding them. These extremes range from the freshwater entering the estuary from rivers and
streams to the saltwater that flows in from the sea.
The Eastern Blue Crabs of San Antonio Bay are a great example. In a typical year most rain falls in
the spring, bringing heavy freshwater flows from the Guadalupe River. These flows reduce salinity
throughout the bay. A hot, dry summer usually follows—flows from the Guadalupe drop, and salinity
increases. Autumn rains send another pulse of freshwater through the system Autumn rains send
another pulse of freshwater through the system and winter...is usually, fairly dry. But during
droughts, bay salinity may become as high as the ocean, or even higher. In very wet years and after
large storms and floods, the bay may be mostly full of fresh water.
Though Blue Crabs are supremely well adapted to this constantly changing environment, they do
have their limits. To understand when salinity for a crab becomes too much of a good thing, we’ve
got to take a deeper dive—first, into the ocean.
Ever wonder how much salt is in the sea? A kilogram of seawater is 96.5 percent water and 3.5
percent salt, which is about 35 grams. Scientists describe that as 35 parts per thousand, or ppt for
short. Putting it another way, one gallon of seawater has about seven-and-a-half tablespoons of salt.
That may not sound like much, but picture this: if you could magically remove the water from all of
the earth's oceans leaving the salt behind, you’d have enough salt to cover the entire planet in a layer
147 feet thick! That’s a lot of salt.
To understand how salinity could become too extreme for a blue crab, you need to know about two
ways of measuring salinity levels. During a typical year in San Antonio Bay, if you look at the data
from all three of our buoys, the salinity varies from 5 to 35 parts per thousand—that’s a range of 30.
The median for the bay as a whole represents the middle salinity value that's collected throughout the
four seasons. You’d appreciate one way that these concepts are important if you were to live for a
year in a place with a cold but variable climate—someplace…like Minnesota.
BACK TO TABLE OF CONTENTS
APPENDIX E: STUDIO SCRIPTS
Estuaries in the Balance
Page 90 of 103
APPENDIX E: STUDIO SCRIPTS
For a typical year, the median annual temperature in Minnesota is about 52 degrees farenheit. But if
you planned your wardrobe based on that fact alone, you’d be in big trouble. That’s because
Minnesota’s temperatures can range from over 100 degress in summer to 30 or 40 degress below zero
on the nastiest of winter days. Dress every morning for the median temp., and in the depths of winter
you’d freeze up solid.
The concept of median is also important for tracking long-term salinity trends in the estuary.
Consider an extreme drought year in San Antonio Bay, with really high salinity for every season
except the spring, when heavy storms flush the estuary with fresh water. The range for the year
might still be from 5 to 35 parts per thousand. But the median salinity, as the middle value in the
series, would be 26, which is much closer to 35 parts per thousand than 5. In this case, the median
reflects the fact that salinity was high most of the time.
Blue crabs can tolerate a broad range of salinity for short periods of time, but they also need
particular salinity levels for different parts of their life cycles.
When an estuary’s age-old seasonal salinty patterns are significantly changed, particularly when
salinity is very high for long periods, blue crabs don’t do so well.
The habitat they depend on for food and protection may be damaged. High salinities may disrupt
their ability to mate and release eggs and it can make them more susceptible to some disease and
parasites.
As adaptable as blue crabs are, when their environment goes to extremes there’s nothing in our
closets that will help them survive. But by using water wisely, those who live upstream can help
ensure that enough freshwater flows to the bay for blue crabs and... all their neighbors.
(Back to Section 2: Blue Crabs - Keys to Success)
Oyster Video
(Back to Section 3: Oyster Reef Builder - Keys to Success)
The oysters of Copano Bay—like oysters everywhere—are the ultimate homebodies. By nature, they
live their entire lives on or near an oyster reef that’s been in place for generations. In fact, an oyster’s
home is made of shells left behind by its ancestors. How’s that for stickin’ with family! Oyster reefs
also make great homes for other creatures. The hard surfaces of the shells, the spaces between them,
the irregular shapes and extended surface areas of oyster reefs provide shelter and food sources for
hundreds of animals, including redfish, crabs, mussels, and barnacles.
Texas is among the top 3 suppliers of oysters in the U.S., which brings millions of dollars to coastal
economies. And oysters have been popular for a long time: Copano Bay is named for the Copane
Indians, who left behind large mounds of oyster shells, called middens, as remnants of their many
feasts.
Today, oyster reefs are among the most endangered habitats on the planet. Worldwide, only 15
percent remain, while in Texas, between 20 and 50 percent survive. Poor water quality, habitat
destruction, and disease are largely responsible for the oyster’s demise along the Coastal Bend.
Water quality declines due to coastal development and nutrient enrichment. People remove the
fundamental building blocks of oyster reefs by dredging—a common method of harvesting oysters.
BACK TO TABLE OF CONTENTS
APPENDIX E: STUDIO SCRIPTS
Page 91 of 103
Estuaries in the Balance
APPENDIX E: STUDIO SCRIPTS
Also, human water use upstream reduces the amounts and changes seasonal patterns of freshwater
inflows. That can result in increased salinity levels that are trouble for oysters. Perhaps more than
any other estuarine creatures, the health of oysters indicates the health of the estuary—because once
oysters join a reef, they stay put.
Adult oysters can tolerate extreme salinity ranges for short periods. Young oysters, however, need
salinity within narrower ranges in order to thrive. Adult males and females release their sperm and
eggs into the water column only if salinity is suitable (generally above 5 parts per thousand). If
conditions are right, the fertilized eggs hatch into larvae that drift freely in the water and pass
through several metamorphic stages.
About three weeks after hatching, the small larvae grow a single “foot”, which earns them the name
pediveligers ("pedi" meaning foot). They settle out of the water column and look for a hard surface to
attach to and call home. The preferred neighborhood: an area with a healthy reef and salinity ranges
of 10 to 28 parts per thousand. The pediveliger then uses its own cement to permanently attach to the
reef. Here it changes once again—this time into a tiny oyster, known as a spat. As the oysters
continue to mature, freshwater inflows from spring and autumn rains lower salinity levels. This
protects oysters from diseases and parasites that are more common when salinity is high.
Scientists and citizens are working to rebuild the oyster reefs of the Texas Coastal Bend by recycling
oyster shells from restaurants. If you live nearby you can join in the fun, and the interactive Reef
Builder game will give you practice. First, good locations must be found for reef building—places
where larval oysters are present, water quality is good, disease levels are low, currents and tides bring
plankton and other food to the growing oysters, and where salinity levels are generally moderate.
Then the shells are loaded onto a barge, and transported to the spot where reef construction can begin.
Over the years, scientists have experimented with different types of reef building materials and reef
designs. Not surprisingly, they’ve found that the best strategies are those that mimic natural reefs—
those with good height, and irregular shapes offering lots of surface area for little spat to make
themselves at home.
Now it’s your turn, reef builder, to get to work bringing back the reefs of Copano Bay!
(Back to Section 3: Oyster Reef Builder - Keys to Success)
Redfish Video
(Back to Section 4: Redfish Angler - Keys to Success)
There it is—a fish tail barely breaking the water’s surface. It’s a telltale sign that redfish are feeding
in the seagrass below. Your line shoots forward, and, in a graceful curve, the fly lands softly, inches
from your target. Mistaking your fly for a snack, the hungry redfish strikes, and the fight is on.
Whether you’re surf-casting for large "bull" redfish, plugging artificial lures along jetties and oyster
reefs, using live bait in the inlets between bay and Gulf, or stalking the flats with a flyrod in your
hand, there’s no better way to connect with the amazing web of life of a Coastal Bend estuary than
angling for redfish!
But it takes more than luck and good eyesight to land one of these fine sportfish in Corpus Christi
Bay. As any seasoned fishing guide will tell you, it helps to know as much as you can about redfish
BACK TO TABLE OF CONTENTS
APPENDIX E: STUDIO SCRIPTS
Estuaries in the Balance
Page 92 of 103
APPENDIX E: STUDIO SCRIPTS
and their habitat. When you've done your homework, you’ll understand why that fish was there
waiting—just for you. And along the way you'll discover how good habitat, clean water, freshwater
inflow, and salinity, all had a part to play.
The Corpus Christi Bay estuary includes several connected marshes, bays, islands, mudflats, and
lagoons. Saline water from the Gulf is carried through passes into the bays by tides, currents, and
wind. Nutrient-rich fresh water flows into the estuary from the Nueces River and its watershed,
which stretches far up into South Central Texas. Redfish, also known as Red Drum. need this
mixture of fresh and salt water to thrive, as do the other plants and animals that populate the habitats
of Corpus Christi Bay.
It's simple really, whether you're a scientist or an angler—healthy bay habitats mean more redfish.
Here’s how it all breaks down: In late August through October, male and female redfish gather
nearshore, just outside the passes that connect the estuary with the Gulf. The females release eggs
that are fertilized by the males and left to drift in the open water. The eggs hatch and become
larvae. Then, suface currents carry the young larvae into shallow bays with seagrass or marsh
habitat. These warm, shallow nurseries are the perfect habitat providing plenty of food and
protection from predators. The larve do best in clean, clear water with moderate salinity levels.
When conditions are right, larvae grow into healthy, young juvenile fish that can reach almost 12
inches during their first year.
As juveniles mature, they can tolerate a wider range of salinity. This allows them to move more
widely through the bay system in search of larger crabs, shrimp and small fish. During much of the
year, young redfish are often found in waters with moderate to higher salinity levels along seagrass
flats that are closer to the Gulf. In the winter and when it's been particularly dry, as salinity levels
rise in the bays, redfish tend to follow prey into the fresher water of the Nueces delta. Redfish do
feed in the open water but they prefer oyster reefs and especially seagrass beds where food is most
plentiful—areas that are typically close to shorelines. That helps explain why Redfish Bay and
Laguna Madre, both chock-full of seagrass habitat, are so popular with redfish.... and anglers.
When juvenile redfish are between three and four years old, they leave the bay system for good to
spend the rest of their adult lives in the Gulf of Mexico. Surf-casters know that exiting redfish during
the spawing season just might provide that trophy they've dreamed of. Adult redfish have been
caught up to five feet long and weighing almost 90 pounds.
Not too long ago, redfish were getting pretty hard to find in the Coastal Bend. Over-fishing in the
1980s did major damage to the fishery. Fortunately, good management, catch limits, and a robust
fish stocking program have revived the redfish population. Restoring more natural freshwater
inflows to Corpus Christi Bay will play a role in revitalizing critical redfish habitat that has been
damaged or lost. It will also insure that enough fresh water will always be "in the mix" at every
important stage in the lifecycle of this amazing Coastal Bend native.
Now it's time, grab your fishing rod and pack a good lunch. ... Where do you want to fish today?
(Back to Section 4: Redfish Angler - Keys to Success)
BACK TO TABLE OF CONTENTS
APPENDIX E: STUDIO SCRIPTS
Estuaries in the Balance
Page 93 of 103
APPENDIX E: STUDIO SCRIPTS
Whooper’s Tale
(Back to Section 5: Whooper's Tale - Keys to Success)
When a whooping crane looks you straight in the eye, you just know there’s something extraordinary
about this tallest of North American birds. You feel their intense concentration as they focus hours
on end foraging for food. You sense their pride in defending their family's territory from intruders.
With a windpipe that's nearly five-feet long, the whooper’s trumpet-like call can be heard for miles.
And when they’re well fed from a winter spent in the marshes of the Texas Coastal Bend, whooping
cranes take to the air for a marathon journey to their summer nesting grounds in far northern
Canada—2,500 miles away!
As a species one of the things that whooping cranes have witnessed is their journey to the brink of
extinction and back. By the 1940s, due mainly to habitat loss and excessive hunting, the world’s
whooping crane population had crashed from about 10,000 in pre-historic times to a total of 21 birds.
Only eight mated pairs remained. The extinction of the species was something that many people had
regretfully come to expect.
But then something truly amazing happened. A small group of scientists set out against huge odds to
make sure that the whooping crane would not join the 13 other species of birds that have become
extinct in our nation’s history. They worked with incredible determination and used some of the most
inventive strategies imaginable. As they learned from their successes and failures, the whoopers were
gradually brought back from the brink. By 2011, the last remaining wild population of whoopers had
grown to 278 birds. Two other flocks of whooping cranes raised in captivity have been
reintroduced in the eastern U.S. This has brought the total whooper population to about 600—still
the smallest population of the world’s 15 species of cranes, but a great cause for hope.
The whooper’s tale is an incredible survival story that is still being written. And the Texas Coastal
Bend is the best spot to witness the last wild, naturally occuring whooping cranes, and a place where
human activities will continue to have a direct impact on the whooper’s recovery.
In their winter home in and around the Aransas Wildlife Refuge, territories are maintained in coastal
marshes by mated pairs and any youngsters born the previous summer—usually one, rarely two. The
mated pairs return to their half-square-mile territories year after year, as the territories are ideally
suited to take advantage of a rich bounty. A highly nutritious diet is essential. The birds must build
fat reserves through the winter for their long and perilous spring migration and for the work of
nesting, breeding and raising the young. As you might guess, most of their winter days are spent
foraging for food.
Whooper territories have low vegetation, which is important for keeping an eye on predators. And
when freshwater flows and salinity levels in the estuary are good, tidal ponds provide plenty of
blue crabs—the whoopers’ most important and nutritious food source. Dense thickets of wolfberries
are also close at hand, as are clams, edible plants, and a variety of small mamals, amphibians,
reptiles, and insects.
The cranes also fly to nearby upland areas, where stands of oak trees offer a steady supply of acorns,
insects and other small critters. Upland areas are visited more often when high salinities due to low
freshwater flows into the estuary reduce the blue crab population and take a toll on the wolfberry crop
by saturating the soil with salt. Also, when this happens, pond water in the marshes can become too
BACK TO TABLE OF CONTENTS
APPENDIX E: STUDIO SCRIPTS
Estuaries in the Balance
Page 94 of 103
APPENDIX E: STUDIO SCRIPTS
saline to drink, and the whoopers must find freshwater ponds elsewhere. More time and engery spent
flying upland for water and less nutritious foods means the whoopers don’t do as well building fat
reserves.
Also, more time spent away from home territories leaves an open door to neighboring whooping
cranes, who often try to expand their own home bases. Defending the home territory from these
interlopers takes up even more energy. Added to these challenges is the increasing development of
coastal areas. Shorelines are retreating due to rising sea levels amplified by our changing climate.
Pollution impacts include common household and industrial contaminants that enter the estuary
through rivers and streams, as well as potential spills of toxic cargoes on barges that use the
intracoastal waterway, which flows through the heart of the whoopers’ wintering grounds.
Growing water needs of expanding communities in the Guadalupe and San Antonio river basins may
be the most important challenge. Water use upstream that significantly reduces fresh water entering
the bay isn’t good for the health of the estuary and its many life forms. Using water wisely within
these watersheds today and in the years ahead will directly impact the recovery of the species.
In the best of times, life isn’t easy for a whooping crane. Human actions have taken them to the brink
of extinction. But today we can take pride in helping the whoopers thrive—that our world will
continue to be enriched by the unison calls of a pair mated for life, by the sight of whoopers soaring
on eight-foot wingspans.
(Back to Section 5: Whooper's Tale - Keys to Success)
Estuaries in the Balance
(Back to Section 6: Estuaries in the Balance - Keys to Success)
It’s not only the hundreds of species of aquatic creatures, birds, and plants that form an estuary’s
rich web of life—- people are also part of the mix in a big way. Sixty-percent of the world’s human
population lives along estuaries and coastlines. Twenty two of the largest cities on the planet were
built on estuaries. With such a bounty of life offered by these cradles of the sea, it’s easy to see why
people would settle on their shores.
In fact, when you put a price tag on the benefits that we receive from estuaries, the results are
staggering. By one measure, San Antonio Bay’s 130,000 acres provide resources and natural services
worth about $1.4 billion each year.
What kinds of “ecological services” are generously provided by estuaries and nearby Gulf waters?
Well, some are obvious, like the incredible abundance of mouthwatering seafood. Eight million
pounds of shrimp, blue crabs, oysters, redfish and other finfish are harvested commercially in the
Coastal Bend area each year.
Sportfish irresistably lure recreational anglers, who annually contribute more than $546 million to
the region’s economy. Bird watchers flock to the Coastal Bend to see spectacular migrating
songbirds, winter species like the majestic whooping crane, and a host of resident birds. The city of
Corpus Christi annually receives about $500 million from birding and nature tourism.
BACK TO TABLE OF CONTENTS
APPENDIX E: STUDIO SCRIPTS
Estuaries in the Balance
Page 95 of 103
APPENDIX E: STUDIO SCRIPTS
Other services provided by Coastal Bend estuaries are less obvious. The tasty oyster, for example,
besides creating high-quality habitat for other aquatic life, also protects shorelines from erosion
through reef building. For more than a century, oyster reefs were dredged and the crushed shells
used as a construction material and for surfacing roads. Also, each oyster filters up to six gallons of
bay water per hour in its constant search of food, which improves water quality by removing
common pollutants.
Even the vegetation in coastal marshes and seagrass beds do their part to reduce pollution with the
help of biofilm that grows on the plants. Bacteria in the biofilm consume nutrients that flow into the
estuary from upstream farms and ranches, cities, and industries. Another ecosystem service is
provided by barrier islands and coastal marshes, which help reduce the impacts of heavy storms. By
absorbing wind and waves, they reduce destructive storm surges—a vital service for communities all
along the Gulf coast. Without a doubt, estuaries provide incredible benefits for people, but not
without losses to the natural system.
Overfishing is a threat to estuaries worldwide. As long ago as 1887, the first Texas fishing
restrictions were put in place on tarpon and other gamefish, as their numbers had crashed due to
overfishing. Redfish were in serious trouble as recently as the 1980's, when our national appetite for
"blackened redfish" almost wiped them out along the Coastal Bend. In Texas, fishing coastal waters
is licensed with restricted catches on many species.
The oyster population, harvested for food and for its shells, has dropped by 50-80 percent in Texas.
Dredging for shells is now prohibited, the harvest is controlled, and reef-building projects seek to
restore reefs.
Blue crabs have been in decline worldwide since the mid 1990s. In Texas, the catch declined seventyfive percent in 20 years. With many fish species dependent upon the millions of eggs released by
each female blue crab, as the crab population shrinks other species are also impacted. Historic
overfishing of blue crabs is one cause of their decline.
Also, Texas has lost half of its coastal wetlands, which are so important to crabs in their early life
stages. Water pollution is another problem. Still another: changes to shorelines caused by rising sea
levels, an issue made worse by human contributions to climate change.
But perhaps even more important than all these concerns is the reduction of freshwater flows into
estuaries caused by a growing human population that uses ever more water. Like a long-lasting
drought, powerful ripple effects are felt throughout the entire ecosystem when water use by people
in upstream watersheds significanly reduces the amounts or changes the patterns of freshwater
flowing into estuaries.
Reduced freshwater inflows means fewer nutrients are available at the bottom of the food chain for
algae, seagrass, and phytoplankton. These, in turn, are food sources for zooplankton and molusks,
which are eaten by blue crabs. But not only do blue crabs have less food, they also suffer—especially
in their early life stages—when low freshwater inflows increase salinity in estuary waters.
BACK TO TABLE OF CONTENTS
APPENDIX E: STUDIO SCRIPTS
Page 96 of 103
Estuaries in the Balance
APPENDIX E: STUDIO SCRIPTS
Many fish that depend on blue crabs must find other food sources when crabs aren’t available.
Likewise, when protein-rich blue crabs are in short supply, endangered whooping cranes must settle
for a poorer diet. This makes it more difficult for the cranes to survive their epic spring migrations to
Canada and successfully reproduce. All of these problems are made worse by recurring droughts.
Our human footprint is different for each estuary along the Coastal Bend. A recent study ranked
Corpus Christi Bay as “unsound” mainly due to the effects of reduced freshwater inflows to the bay.
A similar study ranked San Antonio Bay as “sound.” Yet, many people who study and care about
these wonderful bays see an uncertain future for all of them –a future that calls for Coastal Bend
citizens of all ages to be informed and get involved.
The Guadalupe and San Antonio watersheds are among the fastest growing regions of a state that is
projected to double its population between the years 2000 and 2050—from 20 million to 40 million
people. In the years ahead, everyone living upstream of Coastal Bend estuaries—individuals,
families, and communities—will need to use water resources wisely. Water conservation at home,
recycling water in communities, storing water underground rather than in reservoirs to reduce loss
by evaporation, and desalination are all important strategies.
The estuaries of the Coastal Bend—jewels along the graceful curve of the Texas Gulf shore—are an
invaluable part of the state’s natural heritage. They are gifts for us all, to enjoy and to help sustain.
(Back to Section 6: Estuaries in the Balance - Keys to Success)
BACK TO TABLE OF CONTENTS
APPENDIX E: STUDIO SCRIPTS
Page 97 of 103
Estuaries in the Balance
APPENDIX F: MOLT MANIA SCRIPT
Appendix F
Molt Mania Narration Script for Species Habitats
with Vocabulary
(Back to Section 2: Blue Crabs - Keys to Success)
1. Blue Crabs Molt Mania: Coastal Marsh popup window initial message:
Welcome to the Coastal Marsh. The three major types of marsh found along the Texas Coastal
Bend are true fresh water, brackish or intermediate, and salt water. Together, they form a
transition zone between the open waters of the bays and the dryer, upland Texas prairie. As
salinity changes from fresh to brackish and then to salty, so do the species of plants and animals
that are able to live there. Species that can adapt to changes in salinity do well in this type of
habitat.
2. Blue Crabs Molt Mania: Coastal Marsh, Smooth Cordgrass:
Smooth cordgrass. Smooth cordgrass prefers the salt marsh but can also thrive in brackish marsh
environments. Stands of this tall, smooth grass provides protection for many coastal marsh
species as well as a rich foraging ground for those looking for a meal. Fungi and bacteria break
down decaying leaves and stems of cordgrass so that other organisms can utilize the stored
energy.
3. Blue Crabs Molt Mania: Coastal Marsh, Polychaete worms:
Polychaete worms. Polychaete worms, like the Bloodworm, live in the salt marsh mud. They feed
on the abundant bacteria and other microorganisms found in the decaying plant and animal
material. They are part of an often unseen web of producers and consumers that support the more
visible and well known coastal marsh species.
4. Blue Crabs Molt Mania: Coastal Marsh, Blue Crabs:
Blue Crabs—Adult and Juvenile. Once blue crabs leave the larval stage behind, they grow a shell
and begin the "first crab" stage of their juvenile life. Juveniles then grow and mature through a
series of molts. A molt is when crabs metamorph or "change" by shedding their outer shell and
replacing it with new growth. It takes between 18 and 21 molts for crabs to acheive the larger
shell of adults. The hard shell protects them from many predators and helps them tolerate a wider
range of salinities, allowing them to use the entire estuary as their feeding ground. Crabs strip the
submerged vegetation of grazing snails and other mollusks and the marsh grass provides cover.
5. Blue Crabs Molt Mania: Coastal Marsh, Gulf Salt Marsh Snake:
Gulf Salt Marsh Snake. One way to avoid being eaten by daytime predators is to be active at
night. During the day, the Gulf Salt Marsh Snake hides among shoreline debris and abandoned
crab burrows. This non-venomous hunter emerges at night to feed on shrimp, crabs, small fish
and other invertebrates.
6. Blue Crabs Molt Mania: Coastal Marsh, Whooping Cranes:
The only remaining wild flock of Whooping Cranes in the United States winters in Texas. Each
fall, crane families fly to the coastal marsh around Aransas from their nesting grounds in Canada
BACK TO TABLE OF CONTENTS
APPENDIX F: MOLT MANIA SCRIPT
Estuaries in the Balance
Page 98 of 103
APPENDIX F: MOLT MANIA SCRIPT
– then return to Canada in the spring. Blue crab, a critical source of protein for cranes, is always
on the menu.
7. Blue Crabs Molt Mania: Coastal Marsh, Black-necked Stilt:
Black-necked Stilt. Take a close look at the legs of this common coastal marsh species. They are
also referred to as "daddy longlegs," "stilts," or "longshanks"– perhaps you can see why. From
salty tidal mudflats to fresh water ponds, they hunt polychaetes, mollusks, shrimp, small fish, and
insects.
8. Blue Crabs Molt Mania: Coastal Marsh, Oyster Reef popup window initial message:
Welcome to the oyster reef. Young larval oysters float freely in the water column. Soon they need
a hard surface to attach to in order to grow into adults. Along the Texas Coastal Bend, that hard
surface is most likely going to be other oysters. When salinity, temperature and other estuary
conditions are right, large reefs of oysters form. Oyster reefs help clean the water while providing
habitat for many other estuarine species.
9. Blue Crabs Molt Mania: Coastal Marsh, Oyster Reef, plants:
Phytoplankton. "Phyto" means plant and "plankton" means wanderer or drifter. Most of these
free-floating plants are too small to be seen without a microscope. They are perfectly suited to
float in the water column and are transported to oyster reefs by wind and tides.
10. Blue Crabs Molt Mania: Coastal Marsh, Oyster Reef, Mollusks:
Eastern Oysters. A natural hinge and a strong muscle join the top and bottom shell of an oyster.
They open to use their gills to filter water and capture tiny particles of food like algae and other
plankton. Oysters are popular seafood, not only for people but for other estuary species as well.
11. Blue Crabs Molt Mania: Coastal Marsh, Oyster Reef, Crustaceans:
Blue Crabs—Adults and Juveniles. As blue crabs mature, they move toward lower saline habitats
like oyster reefs. Juveniles grow and mature through a series of molts. A molt is when crabs
metamorph, or "change" by shedding their outer shell and replacing it with new growth. It takes
between 18 and 21 molts for crabs to acheive the larger shell of adults. Juvenile crabs need food
and protection from predators that the complex structure of the reef provides. Adult crabs are well
equipped with strong claws to pry open and eat clams and oysters.
12. Blue Crabs Molt Mania: Coastal Marsh, Oyster Reef, Fish:
The Atlantic Croaker . The Atlantic Croaker is a relative of two other popular Coastal Bend
sportfish – the Redfish and the Spotted Seatrout. Males "croak" by vibrating special air-filled
swim bladders during spawning season. Juvenile crabs along the oyster reef need to watch out for
this predator.
13. Blue Crabs Molt Mania: Coastal Marsh, Oyster Reef, Birds:
American Oystercatcher. Pink legs and a bright orange bill make the American Oystercatcher an
easy bird to identify. At low tides when oyster reefs are exposed, they feed on many estuarine
species including oysters and crabs. During nesting season, they distract predators by pretending
to be hurt and leading them away from their chicks.
BACK TO TABLE OF CONTENTS
APPENDIX F: MOLT MANIA SCRIPT
Estuaries in the Balance
Page 99 of 103
APPENDIX F: MOLT MANIA SCRIPT
14. Blue Crabs Molt Mania: Seagrass popup window initial message:
Welcome to Seagrass habitat. Seagrasses are submerged flowering plants that are almost always
covered by water. Five species common to Texas grow in bays, lagoons and shallow coastal
waters. Seagrasses have leaves, stems, flowers, seeds and roots and use the process of
photosynthesis to produce food and oxygen. A seagrass meadow provides food for large and
small grazing aquatic animals and waterfowl, hiding places for small invertabrates and fish, and a
hunting ground for larger predators.
15. Blue Crabs Molt Mania: Seagrass, Plants:
Shoal grass is the most abundant species along the Texas coast. It has fine blades that are 1 to 3
millimeters in width and 5 to 40 millimeters in length. Large meadows are found along the
Coastal Bend where it grows best in higher salinity waters. Shoal grass beds may be exposed
during low tides.
16. Blue Crabs Molt Mania: Seagrass, Crustaceans #1:
Brown Shrimp. Brown shrimp mature from egg to larval stages while freely floating in the water
column of the Gulf of Mexico and the inlets to bays. Winds and tides move larval and juvenile
shrimp "up estuary" to seagrass beds where they feed on decomposing seagrass leaves, small
worms and other organisms. Brown Shrimp are an important link in the energy flow between
organic material found in sediments and larger species who prey on the shrimp.
17. Blue Crabs Molt Mania: Seagrass, Crustaceans #2:
Blue Crabs —Megalops, Juveniles, and Adults. When blue crabs reach the megalopal stage of
development they become good swimmers. There is plenty of food and protection for them in
seagrass habitat and they prefer the higher salinity water found there. They scavenge along the
bottom feeding on fish larve, small shellfish and aquatic plants. Once megalops reach the "first
crab stage" these new juvenile crabs continue to grow and mature through a series of molts. A
molt is when crabs metamorph, or "change" by shedding their outer shell and replacing it with
new growth. It takes between 18 and 21 molts for crabs to achieve the larger shell of adults.
Juvenile and adult blue crabs find food and protection in seagrass beds as well.
18. Blue Crabs Molt Mania: Seagrass, Fish #1:
Pinfish. Juvenile pinfish prefer the high salinity habitat that seagrass beds provide. They feed on
shrimp, fish eggs, larval insects and polychaete worms that burrow in the sand and mud. Seagrass
provides pinfish with hiding places from larger predators that feed on them.
19. Blue Crabs Molt Mania: Seagrass, Fish #2:
Redfish (Red Drum). Juvenile Redfish thrive in shallow water with submerged vegetation that
provides habitat for the food they like to eat. Young redfish feed on small crabs, shrimp and
marine worms. As they get older they feed on larger crabs and small fish like the pinfish. You can
often see their tails waving above the water as they feed in the seagrass habitat below.
20. Blue Crabs Molt Mania: Open Bay popup window initial message:
Welcome to the Open Bay. The open bay might be considered the "lifeblood of aquatic
ecosystems." It connects all the other habitats throughout the estuary and bay. Some species move
up and down the water column responding to light, temperature and opportunities to feed. Others
BACK TO TABLE OF CONTENTS
APPENDIX F: MOLT MANIA SCRIPT
Page 100 of 103
Estuaries in the Balance
APPENDIX F: MOLT MANIA SCRIPT
are simply carried along in the water by wind, currents and tides. Many estuarine species must
travel through the open bay at some stage in their life cycle to reach other habitats they need to
survive.
21. Blue Crabs Molt Mania: Open Bay, Crustaceans #1:
Blue Crabs—Adult Females with Eggs. After mating, adult females move "down estuary"
towards inlets or passages between the Gulf of Mexico and the estuary. Here, females release
their eggs to float in the water column. The eggs quickly hatch into the first larval stage called
Zoea.
22. Blue Crabs Molt Mania: Open Bay, Crustaceans #2:
Blue Crabs—Larvae. Zoea are larval crabs in the first seven stages of development. When blue
crab larvae emerge from the eggs, they look more like a tiny insects than crabs. They float in the
water column where winds, currents and tides carry them into the estuary.
23. Blue Crabs Molt Mania: Open Bay, Zooplankton:
Zooplankton. "Zoo" means animal and "plankton" means wanderer or drifter. Some zooplankton,
like the jellyfish are large, but most species are too small to be seen with the unaided eye. Like
other microscopic species they are perfectly suited to float and move within the water column.
They feed on smaller plants and animals including the tiny, larval blue crab.
24. Blue Crabs Molt Mania: Open Bay, Fish:
Striped Mullet. Striped Mullet spend much of their time in bays, inlets and lagoons that have sand
or mud bottoms. Adults range from 9 to 19 inches long and they often travel in schools as
protection from larger predators like redfish. They feed on dead plants and animals, zooplankton
and small invertebrates.
25. Blue Crabs Molt Mania: Open Bay, Reptiles:
Kemps Ridley Sea Turtle. After mating, females leave the open Gulf waters and head to some
Texas beaches to lay their eggs in the sand. Inlets connecting the Gulf of Mexico to the open bays
lead them to the rich variety of life in the estuary. Blue crabs are top on their menu but they also
eat fish, clams, sea cucumbers, jellyfish and some plants.
(Back to Section 2: Blue Crabs - Keys to Success)
Molt Mania Vocabulary
•
•
•
•
Adapt(ed) - The process whereby an individual adjusts to changing conditions within its
habitat or a population, and becomes better suited to its habitat.
Algae - Microscopic, single cell plants found in a variety of aquatic environments.
Aquatic - Relating to water; living in or near water, taking place in water.
Bacteria - A large domain of microorganisms. Typically a few micrometers in length,
bacteria are present in most habitats on the planet.
BACK TO TABLE OF CONTENTS
APPENDIX F: MOLT MANIA SCRIPT
Estuaries in the Balance
Page 101 of 103
APPENDIX F: MOLT MANIA SCRIPT
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Bay(s) - A large, semi-enclosed body of water connected to an ocean through a tidal pass and
receiving fresh water from a river basin. A large bay may be called a gulf, a sea, a sound, or a
bight.
Blue Crabs (Eastern blue crabs) - A species of crab native to the waters of the western
Atlantic Ocean, the Pacific coast of Central America and the Gulf of Mexico. The blue crab is
an important part of the estuarine food web, and of significant seafood value and economic
importance in the United States.
Brackish - Salty to slightly salty water, resulting from a mixture of fresh and seawater, such
as that found in estuaries.
Consumer(s) - Any organism that eats producers, or other consumers, as food
Crab burrow(s) - A hole or tunnel dug into the ground by a crab to create a space suitable for
habitation and protection from predators.
Debris - Rubble, wreckage, ruins, litter and discarded garbage.
Decomposing - Decomposition (or rotting) is the process by which organic substances are
broken down into simpler forms of matter. The process is essential for recycling the finite
matter.
Ecosystem(s) - A system formed by the interaction of a community of organisms with their
physical environment.
Estuarine - Of or having to do with the area where the sea meets a freshwater stream/river.
An oyster is an estuarine animal.
Estuary(ies) – A partly enclosed coastal body of water with one or more rivers or streams
flowing into it, and with a free connection to the open sea. Estuaries are amongst the most
heavily populated areas throughout the world, with about 60% of the world’s population
living along estuaries and the coast. As a result, estuaries are suffering degradation by many
factors.
Flock(s) - A group of birds typically engaged in a similar behavior in flight, or while
foraging.
Freshwater (fresh water) - Naturally occurring water on the Earth's surface in ice sheets, ice
caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in
aquifers and underground streams. Fresh water is generally characterized by having low
concentrations of dissolved salts and other total dissolved solids.
Fungus(i) - A member of a large group of organisms that includes microorganisms such as
yeasts and molds as well as the more familiar mushrooms.
Habitat(s) – An area that provides food, water and/or shelter for a particular species of
animal, plant, or other type of organism.
Invertebrate(s) - Animal species that do not develop a vertebral column.
Juvenile(s) – An individual organism that has not yet reached its adult form, sexual maturity
or size. Juveniles sometimes look very different from the adult form.
Lagoon(s) - A shallow, elongated body of water separated from a larger body of water by
barrier islands or reefs.
Larva(l) - A distinct juvenile form that many animals undergo before metamorphosis into
adults. The larva's appearance is generally very different from the adult form. A larva often
has unique structures and organs that do not occur in the adult form. Larvae are frequently
adapted to environments separate from adults. Some species such as barnacles are immobile
as adults, and use their mobile larval form to distribute themselves.
BACK TO TABLE OF CONTENTS
APPENDIX F: MOLT MANIA SCRIPT
Estuaries in the Balance
Page 102 of 103
APPENDIX F: MOLT MANIA SCRIPT
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Marine worms - Any worm that lives in a marine environment is considered a marine worm.
Marsh(es) or coastal marsh(es) - A type of wetland that is dominated by herbaceous rather
than woody plant species. Marshes often form a transition between the aquatic and terrestrial
ecosystems, are important nursery areas and highly productive.
Megalopa(ae) or megalops - When blue crabs reach the megalopal stage of development
they become good swimmers. There is plenty of food and protection for them in sea grass
habitat and they prefer the higher salinity water found there.
Microorganisms - An organism of microscopic size, such as bacterium.
Microscopic - Something microscopic is too small to be seen by the naked eye, requiring a
lens or microscope to see them clearly.
Mollusks - A large group of invertebrate animals. Around 85,000 species are recognized.
Because mollusks have such a varied range of body structures, it is difficult to find defining
characteristics to apply to all modern groups. The two most universal features are a mantle
with a significant cavity used for breathing and excretion, and the structure of the nervous
system.
Molt(s) - Molting is the manner in which an animal routinely casts off a part of its body
(often but not always an outer layer or covering), either at specific times of year, or at specific
points in its life cycle.
Mudflats (tidal) - Also known as tidal flats, are coastal wetlands that form when tides or
rivers deposit mud. They are found in sheltered areas such as bays, bayous, lagoons, and
estuaries.
Nesting season - The time of year during which birds and some other animals, particularly
some reptiles, build nests, lay eggs in them, and in most cases bring up their young. It is
usually in the spring.
Organic material - Broken down remains of plants and animals in the environment.
Organisms - Any contiguous living system (such as animal, fungus, micro-organism, or
plant). In at least some form, all types of organisms are capable of response to stimuli,
reproduction, growth and development, and maintenance of homeostasis as a stable whole.
Oxygen - A chemical element. It is an important part of the atmosphere and is necessary to
sustain most terrestrial life.
Oyster reef(s) - Reefs formed by oysters.
Oyster(s) (Eastern Oyster(s)) - A group of bivalve mollusks, which live in marine or
brackish habitats. Humans commonly consume some kinds of oyster as a delicacy. Other
kinds are harvested for the pearl produced within the mantle.
Photosynthesis - A process used by plants and other organisms to convert the light energy
captured from the sun into chemical energy that can be used to fuel the organism's activities.
Photosynthesis occurs in plants, algae, and many species of bacteria.
Phytoplankton - Photosynthesizing microscopic organisms that drift the upper sunlit layer of
almost all oceans and bodies of fresh water. They are agents for "primary production" and
account for half of all photosynthetic activity on Earth.
Plankton - Any organisms (animal, plant, bacteria, etc.) that drift in the water column and are
incapable of swimming against a current. They provide a crucial source of food to many large
aquatic organisms, such as fish and whales.
Prairie - Grassland ecosystems found in temperate climates with moderate rainfall. A
composition of grasses, herbs, and shrubs, rather than trees, is the dominant vegetation type.
BACK TO TABLE OF CONTENTS
APPENDIX F: MOLT MANIA SCRIPT
Estuaries in the Balance
Page 103 of 103
APPENDIX F: MOLT MANIA SCRIPT
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Producers - An organism that produces food from by using energy from light (by
photosynthesis) or inorganic chemical reactions.
Protein - Large biological molecules consisting of one or more chains of amino acids.
Proteins perform a vast array of functions within living organisms.
Range(s) - In a set of data, the range is the difference between the largest and smallest values.
Redfish (or Red Drum) - An economically important game fish that is found in the Atlantic
Ocean from Massachusetts to Florida and in the Gulf of Mexico from Florida to Northern
Mexico.
Salinity(ies) - Salinity is the saltiness or dissolved salt concentration in water or within
coastal soil.
Sea cucumbers - Marine invertebrates with a leathery skin and an elongated body. Sea
cucumbers are found on the sea floor worldwide.
Seagrass meadow(s) or bed(s) - Highly diverse and productive ecosystems that are nursery
grounds for many marine species.
Seagrass(es) - Flowering plants, which grow in marine environments.
Seawater (salt water) - Water originating from a sea or ocean.
Snails - The common name "snail" is applied to most mollusks that have a coiled shell large
enough for the animal to retract completely into. It includes not just land snails but also
thousands of species of sea snails and freshwater snails.
Spawning season - Spawning is the process of releasing the eggs and sperm. Spawning often
happens during a particular annual season.
Sport fish - Game fish are fish pursued for sport by recreational anglers. They can be
freshwater or marine fish.
Submerged - Being entirely underwater.
Swim bladders - An internal gas-filled organ that contributes to the ability of a fish to control
its buoyancy, and thus to stay at the current water depth without having to waste energy in
swimming.
Tide(s) - The rise and fall of sea levels caused by the combined effects of the gravitational
forces exerted by the Moon and the Sun and the rotation of the Earth.
Water column - A conceptual column of water from surface to bottom sediments.
Waterfowl - Birds, which includes ducks, geese, and swans.
Zooplankton - Animals (or organisms that eat other organisms) that drift in the water column
and are incapable of swimming against a current. Individual zooplankton are usually too
small to be seen with the naked eye, but some, such as jellyfish, are large.
BACK TO TABLE OF CONTENTS
APPENDIX F: MOLT MANIA SCRIPT