Download A Population Growth Curve Using Southern Sea Otter

Primary Type: Lesson Plan
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 128807
Sea Otter Spotter - A Population Growth Curve Using
Southern Sea Otter Census Data
Students explore the world of population biology using the sea otter as a case study. The lesson involves reading technical reports from the US Fish
and Wildlife Service as well as reading information about the sea otter from non-governmental organizations. Students are introduced to a
specialized wildlife capture technique and monitoring of the endangered population through annual census data. Using that data students explore the
limiting factors affecting sea otter growth and apply mathematical knowledge to analyze population growth curves. Students also produce an
argument on whether the sea otter has met criteria and should be removed from the endangered species list.
Subject(s): Science
Grade Level(s): 9, 10
Intended Audience: Educators
Suggested Technology: Computer for Presenter,
Computers for Students, Internet Connection,
Interactive Whiteboard, Overhead Projector, Microsoft
Office, GeoGebra Free Software (Download the Free
GeoGebra Software), Smart Phone/Tablet
Instructional Time: 1 Hour(s) 30 Minute(s)
Resource supports reading in content area: Yes
Keywords: carrying capacity, abiotic, biotic, logistic growth, exponential growth, limiting factors, sea otter, census
data, population growth, birth rate, carrying capacity, death rate, demography, density-dependent, densityindependent, emigration, immigration, , J Curve, K, S Curve
Resource Collection: FCR-STEMLearn Diversity and Ecology
ATTACHMENTS
Card Sort for Sea Otter Spotter Vocab Review.docx
Sea Otter Spotter Graphing Activity.docx
Sea otter growth and population report.docx
Sea Otter Census Data 1983-2014.xlsx
The Population Biology For Sea Otter Spotter.pptx
LESSON CONTENT
Lesson Plan Template: General Lesson Plan
Learning Objectives: What will students know and be able to do as a result of this lesson?
1. The student will be able to describe how births, deaths, immigration, emigration, abiotic, and biotic factors affect population size of California sea otters.
2. The student will be able to explain population density, logistic growth, exponential growth, and carrying capacity.
3. The student will be able to graph sea otter data and interpret the growth curve.
Prior Knowledge: What prior knowledge should students have for this lesson?
1. Students should have a basic understanding of concepts of abiotic and biotic factors.
2. Students should have been introduced to calculation of population density.
3. Students should have knowledge of logistic and exponential growth curves.
page 1 of 3 4. Students should have been exposed to the use of Excel for creating graphs, tables, and figures.
5. Students should have an understanding of the Endangered Species Act and the mechanisms behind listing and de-listing an animal.
Guiding Questions: What are the guiding questions for this lesson?
1. What are the factors that contribute to population size and density?
(answers should include births, deaths, immigration, emigration, and amount of animals in an area)
2. How do these factors directly affect population size of a species?
(answers should include births, deaths, immigration, and emigration affect population size directly by either enlarging or reducing the population immediately,
density is more of an indirect effect)
3. Can sea otter growth be explained using both logistical and exponential growth?
(no - sea otter growth is very slow and is happening in a more linear fashion)
4. How are the factors above used to calculate or determine carrying capacity?
(the density of an animal population can be determined by factors such as resources, as the population is increasing that can affect the environment and how many
resources are available which will determine carrying capacity)
Engage: What object, event, or questions will the teacher use to trigger the students' curiosity and engage them in the concepts?
Begin the lesson by showing a YouTube video of sea otter capture and census, "A View from Below: Sea Otter Capture" by CalSpillWatch.
Follow the video with a quick question and answer discussion. This formative assessment will give you the opportunity to assess initial understanding and introduce
concepts for the lesson plan.
Ask the following questions:
1. Abiotic and Biotic factors – Imagine a sea otter population along the California Coast. What are three abiotic and three biotic factors that might affect population
growth?
(Abiotic – water oil spills, El Nino events, global climate change; Biotic – resource limitation, at carrying capacity, intra­species competition)
2. What two measures are needed to calculate otter population density in the most basic way?
(number of sea otters ÷ the area they occupy = population density
3. How do logistic and exponential curves differ?
(logistic is limited growth and exponential is unbounded growth)
4. Once an animal or plant is listed under the Endangered Species act, who ultimately manages the population? How can the organism's status change?
(USFWS; by meeting specific requirements laid out in the recovery plan and being down listed or de-listed or by dying out and becoming extinct.)
Explore: What will the students do to explore the concepts and skills being developed through the lesson?
Discuss the vocabulary needed to understand carrying capacity and population size using a card sort (see Sea Otter Spotter vocab attachment). Directions for card
sort:
1. Pass out two sets of cards to each pair of student. Each pair should get a set of vocabulary words and a set of definitions.
2. Set a 3 minute timer and instruct the students that they have 3 minutes to match the words to the definitions.
3. Walk around to observe how well the kids are matching vocab words and definitions.
4. When everyone is done have a student from one pair stand up and say any word and its definition.
5. Repeat this for all the pairs and continue until all the words have been defined correctly.
The card sort activity can be followed by the Population Biology for Sea Otter Spotter PowerPoint presentation. These slides provide a review of the key concepts and
vocabulary specifically related to sea otter population growth.
Explain: What will the students and teacher do so students have opportunities to clarify their ideas, reach a conclusion or
generalization, and communicate what they know to others?
Read and review "Sea Otter Population Growth," a synopsis of the history of sea otters and their growth from Defenders of Wildlife. Use the first two Guiding
Questions to stimulate a class discussion about how limiting factors and predation affect sea otter population size and carrying capacity:
1. What are the factors that contribute to population size and density? (answers should include births, deaths, immigration, emigration, and amount of animals in an
area)
2. How do these factors directly affect population size of a species? (answers should include births, deaths, immigration, and emigration affect population size directly
by either enlarging or reducing the population immediately, density is more of an indirect effect)
Next, students will graph census data using real survey data for Southern Sea Otters. Depending on resources available, students can work independently, in pairs, or
in small groups. Pass out the Sea Otter Spotter Graphing Activity worksheet, which will provide instructions for students, and provide students with the attached Excel
file "Sea Otter Census Data 1983-2014."
Elaborate: What will the students do to apply their conceptual understanding and skills to solve a problem, make a decision,
perform a task, or make sense of new knowledge?
Students will be assigned the role of a wildlife biologist. They will have to analyze the sea otter census data and determine if it fits a logistic or exponential growth
curve (or neither). They will write a report, and be graded, based on the following criteria:
Abiotic and biotic factors that are affecting sea otter population growth
Immigration and emigration of sea otters between sub-populations
The limiting factors that might play a role in sea otter recovery
The type of growth that the Southern sea otter population is experiencing.
Give each student the "Sea otter growth and population report" worksheet. The worksheet provides instructions for writing the report but also provides hyperlinks to
research articles. If the worksheet is printed and passed out, provide students with the following links:
Defenders of the Wildlife, "Threats to Southern Sea Otters Taking a Toll on Population Growth"
USFWS Ventura office, "Feature Story: Slowly Swimming Towards Recovery, California's Sea Otter Numbers Holding Steady"
USFWS Ventura office, "Final Revised Recovery Plan for the Southern Sea Otter," pages ix - x.
page 2 of 3 Summative Assessment
The summative assessment will be given after the graphing exercise and following discussion. The assessment involves writing a report using specific criteria. Details
are provided in the Elaborate section and on the Sea otter growth and population report attachment.
Formative Assessment
Class discussion throughout the lesson plan provides multiple opportunities for assessing student understanding:
The question and answer session after the video (Engage section)
the discussion after the vocabulary word sort activity (Explore)
A final opportunity for assessment occurs during the graphing activity. The teacher can walk around checking students' work and their progress.
Feedback to Students
The students will be given feedback during a card sort identifying their knowledge of the vocabulary required for the exercise. Students will also be helped during the
graphing process and subsequent analysis of a sea otter growth curve.
The students will be given feedback in the class period where they are graphing sea otter census data.
ACCOMMODATIONS & RECOMMENDATIONS
Accommodations:
1. The requirement for researching multiple resources could be condensed into a key for students that have difficulty reading/writing/researching or who do not have
access to technology outside of school.
2. The report can be handwritten if students do not have access to technology outside of school and the rubric would be adjusted.
3. Alternatively the in school work period could be extended from one day of lecture/graphing and analysis and one day of writing to add an additional day for writing.
Extensions:
1. Based on the current USFWS management plan for sea otter management, students can decide if they think the sea otter should remain listed as an endangered
species, be moved down to threatened, or be delisted entirely.
2. This activity could be tied to a study of the trophic ecology of sea otters and kelp forests ecosystems.
3. The activity could also spawn a discussion of marine ecosystems versus freshwater ecosystems and apex predators.
Suggested Technology: Computer for Presenter, Computers for Students, Internet Connection, Interactive Whiteboard, Overhead Projector, Microsoft Office,
GeoGebra Free Software, Smart Phone/Tablet
Special Materials Needed:
Excel on school computers
Excel -Census data loaded on computers
Teacher should print cards (1 set for every pair of students) and cut cards for vocabulary sorting activity
Further Recommendations:
The teacher might want to spend a few minutes at the beginning of the activity reviewing any necessary vocabulary/concepts and evaluating students' knowledge. This
could be done easily using any clicker software or an app such as Plickers.
SOURCE AND ACCESS INFORMATION
Contributed by: Alisha Kage
Name of Author/Source: Alisha Kage
District/Organization of Contributor(s): Alachua
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Name
Description
Analyze how population size is determined by births, deaths, immigration, emigration, and limiting factors (biotic and
abiotic) that determine carrying capacity.
SC.912.L.17.5:
Remarks/Examples:
Annually assessed on Biology EOC. Also assesses SC.912.L.17.2 SC.912.L.17.4 SC.912.L.17.8 SC.912.N.1.4.
MAFS.912.S-IC.2.4:
Use data from a sample survey to estimate a population mean or proportion; develop a margin of error through the
use of simulation models for random sampling. ★
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