Download Export To Word

Sea Otter Spotter - A Population Growth
Curve Using Southern Sea Otter Census
Data
Resource ID#: 128807
Primary Type: Lesson Plan
This document was generated on CPALMS - www.cpalms.org
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, density-independent, emigration, immigration, , J Curve, K, S
Curve
Instructional Component Type(s): Lesson Plan
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.
2.
3.

Prior Knowledge: What prior knowledge should students have for this lesson?
1.
2.
3.
4.
5.

The student will be able to describe how births, deaths, immigration, emigration, abiotic, and
biotic factors affect population size of California sea otters.
The student will be able to explain population density, logistic growth, exponential growth, and
carrying capacity.
The student will be able to graph sea otter data and interpret the growth curve.
Students should have a basic understanding of concepts of abiotic and biotic factors.
Students should have been introduced to calculation of population density.
Students should have knowledge of logistic and exponential growth curves.
Students should have been exposed to the use of Excel for creating graphs, tables, and figures.
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.
2.
3.
4.

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)
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)
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)
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.
2.
3.
4.

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, intra-species competition)
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
How do logistic and exponential curves differ?
(logistic is limited growth and exponential is unbounded growth)
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.
2.
3.
4.
5.
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.
Set a 3 minute timer and instruct the students that they have 3 minutes to match the words to the
definitions.
Walk around to observe how well the kids are matching vocab words and definitions.
When everyone is done have a student from one pair stand up and say any word and its definition.
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.
2.
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)
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:
o
o
o
o
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:
o
o
o

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.
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:
o
o
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.
2.
3.

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.
The report can be handwritten if students do not have access to technology outside of school and
the rubric would be adjusted.
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:
o
o
o

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
License: CPALMS License - no distribution - non commercial
Related Standards
Name
SC.912.L.17.5:
MAFS.912.S-IC.2.4:
Description
Analyze how population size is determined by births, deaths,
immigration, emigration, and limiting factors (biotic and
abiotic) that determine carrying capacity.
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.
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. ★