SCIENCE
EXTENDED LEARNING MODULES
TEACHER PACKET
Biology
SC.912.L.17.5
OFFICE OF ACADEMICS AND TRANSFORMATION
2012-2013
THE SCHOOL BOARD OF MIAMI-DADE COUNTY, FLORIDA
Ms. Perla Tabares Hantman, Chair
Dr. Martin Karp, Vice Chair
Dr. Dorothy Bendross-Mindingall
Ms. Susie V. Castillo
Mr. Carlos L. Curbelo
Dr. Lawrence S. Feldman
Dr. Wilbert “Tee” Holloway
Dr. Marta Pérez
Ms. Raquel A. Regalado
Mr. Jude Bruno
Student Advisor
Mr. Alberto M. Carvalho
Superintendent of Schools
Ms. Milagros R. Fornell
Chief Academic Officer
Office of Academics and Transformation
Ms. Marie L. Izquierdo
Assistant Superintendent
Division of Academics, Accountability & School Improvement
Office of Academics and Transformation
Dr. Pablo G. Ortiz
Assistant Superintendent
Education Transformation Office
Office of Academics and Transformation
Mr. Cristian Carranza
Executive Director
Department of Mathematics and Science
Office of Academics and Transformation
Introduction
The purpose of this document is to provide students with enhancement tutorial sessions that will
enrich the depth of content knowledge of the Biology 1 course. Each tutorial session is aligned
to Biology Annually Assessed Benchmarks of the Next Generation Sunshine State Standards
(NGSSS) as described in the course description and the Biology Item Specifications and include
an ExploreLearning Gizmos activity and/or a science demonstration followed by assessment
questions.
The Nature of Science Body of Knowledge (BOK) is embedded in all lessons. Teachers are
encouraged to generate an inquiry-based environment where students grow in scientific thinking
while creating and responding to higher-order questions.
Prior to the day of the activity
 The teachers facilitating the session must read the complete packet prior to instruction to
ensure effective implementation of the lesson.
 The teachers must review the Biology Item Specifications relating to each activity in order
to focus their instruction.
 If this is the first time for the facilitating teacher doing this activity, the teacher should try
the activity prior to the session to anticipate any problems that may be encountered and
to prepare the type of support that he/she needs to provide to the students.
The day of the activity
 The topic of the tutorial must be written on the board.
 Student prior knowledge must be assessed using a KWL, lead-in/essential questions, or
a class discussion.
 Always before starting the activity, students must be asked to generate their own
hypothesis.
 Because the Nature of Science BOK is embedded in all scientific activities, the teacher
must make reference to all parts of the process of science as the students work through
the activity.
 As the students work with the teacher through the Student Guide, the students must
answer all questions on the hand-out.
 When appropriate, a data table compiling all demonstration data must be drawn on the
board for class discussion.
 Based on the data of the activity, the teacher should facilitate a class discussion by
asking the following questions: 1) What do we observe from the data? 2) How does the
data support the expected outcomes? 3) How do you explain the variations in data
among experiments? 4) What are some possible errors in this data?
 Once the teacher facilitator feels that the students have an in-depth understanding of the
concepts, the students with the teacher guidance must be directed to work on the
Assessment.
 If some or all the students have already done any of these activities, you have the choice
of selecting any or all of the activities included in the packet.
Timeline:
 Activities with class discussion and assessment – 3 hours
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Table of Contents
Organisms, Populations, and Ecosystems - SC.912.L.17.5 Analyze how population size is
determined by births, deaths, immigration, emigration, and limiting factors (biotic and abiotic)
that determine carrying capacity. (Also assesses SC.912.N.1.4, SC.912.L.17.2, SC.912.L.17.4,
and SC.912.L.17.8)
Item Specifications......................................................................................................................3
Teacher Guide 1 – Limiting Factors ............................................................................................5
Activity 1 – Limiting Factors ........................................................................................................5
Teacher Guide 2 – Rabbit Population by Season .......................................................................6
Activity 2 – Rabbit Population by Season .................................................................................10
Teacher Guide 3 – Literacy in the Content Area .......................................................................17
Activity 3 - Literacy in the Content Area ....................................................................................17
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Item Specifications
Benchmark SC.912.L.17.5 Analyze how population size is determined by births, deaths,
immigration, emigration, and limiting factors (biotic and abiotic) that determine carrying capacity.
(Also assesses SC.912.L.17.2, SC.912.L.17.4, SC.912.L.17.8, and SC.912.N.1.4.)
Reporting Category: Organisms, Populations, and Ecosystems
Standard 17: Interdependence
Also Assesses:
 SC.912.L.17.2 Explain the general distribution of life in aquatic systems as a function of
chemistry, geography, light, depth, salinity, and temperature.
 SC.912.L.17.4 Describe changes in ecosystems resulting from seasonal variations,
climate change, and succession.
 SC.912.L.17.8 Recognize the consequences of the losses of biodiversity due to
catastrophic events, climate changes, human activity, and the introduction of invasive,
non-native species.
 SC.912.N.1.4 Identify sources of information and assess their reliability according to the
strict standards of scientific investigation.
Benchmark Clarifications:
 Students will use data and information about population dynamics, abiotic factors, and/or
biotic factors to explain and/or analyze a change in carrying capacity and its effect on
population size in an ecosystem.
 Students will explain that different types of organisms exist within aquatic systems due to
chemistry, geography, light, depth, salinity, and/or temperature.
 Students will describe the potential changes to an ecosystem resulting from seasonal
changes, climate changes, and/or succession.
 Students will identify positive and/or negative consequences that result from a reduction
in biodiversity.
 Students will assess the reliability of sources of information according to scientific
standards.
Content Limits:
 Items referring to chemical factors in aquatic systems are limited to pH, oxygen, carbon
dioxide, nitrogen, phosphorous, and salinity.
 Items referring to geography in aquatic systems are limited to water depth, latitude,
temperature, underwater topography, and proximity to land.
 Items will not require the identification of oceanic zones.
 Items must focus on changes to the ecosystem and not on how a single population
changes responds to seasonal changes, climate changes, and/or succession.
 Items referring to reduction in biodiversity may include examples of catastrophic events,
climate changes, human activities, and the introduction of invasive and nonnative
species, but they will not assess specific knowledge of these.
 Items referring to reduction in biodiversity will focus on the consequence and not require
knowledge of the specific event that led to the reduction.
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

Items addressing climate change are limited to biodiversity, population dynamics, and
ecosystem contexts.
Items addressing sources of information and reliability of information are limited to
population dynamics, distribution of life in aquatic systems, changes in ecosystems, and
biodiversity.
Stimulus Attributes:
None specified
Response Attributes:
Responses in items referring to sources of information should be specific to the context of the
item instead of generic statements.
Prior Knowledge:
Items may require the student to apply scientific knowledge described in the NGSSS from lower
grades. This benchmark requires prerequisite knowledge of SC.7.L.15.2, SC.7.L.15.3,
SC.7.L.17.3, SC.7.E.6.6, SC.6.E.7.7, SC.8.N.4.1, and SC.8.N.4.2.
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Teacher Guide 1 – Limiting Factors
Engage (10 – 15 minutes)
Using the questions below, ask students to choose one as a topic for a journal entry/discussion
or multiple questions can be used for a concentric circle discussion.
Activity 1 – Limiting Factors
Using the questions below, choose one as a topic for a journal entry or discussion.
1. Why are some species more vulnerable to extinction than others? Explain.
2. What challenges do we face with this human unprecedented growth? Explain.
3. Describe changes in ecosystems resulting from seasonal variations, climate change, and
succession.
4. What is a consequence of reduction in biodiversity?
5. Complete this statement. Invasive species and non-native species….
6. Explain the difference in the amount of available energy in the trophic levels.
7. Complete this statement. If an area of forest trees is cleared to build a community, then….
8. How does emigration affect population growth?
9. Complete this statement. Ecosystems change because…
10. What accounts for the great diversity of organisms?
11. If an oil spill occurs, then organisms in an aquatic system will… Explain.
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Teacher Guide 2 – Rabbit Population by Season
Learning Objectives
 Interpret a graph of population growth.
 Explain what happens to a population when it reaches carrying capacity.
 Describe how limiting factors affect a population.
 Understand the effects of density-dependent and density-independent limiting factors.
Vocabulary
 Carrying capacity – the maximum number of individuals of a particular species that an
environment can support.
o Before a population reaches its carrying capacity, it grows rapidly. As the population
nears its carrying capacity, growth slows. Once the population is at carrying capacity,
overall growth stops as the population stabilizes. The population will remain at the
carrying capacity until a limiting factor in the environment changes.
 Density-dependent limiting factor – a limiting factor that only affects a population when its
density reaches a certain level.
o The amount of available living space is one example of a density-dependent limiting
factor.
 Density-independent limiting factor – a limiting factor that affects a population regardless
of its size and density.
o Unusual weather is one example of a density-independent limiting factor.
 Limiting factor – any factor that prevents a population from growing larger.
o Examples of limiting factors include competition, disease, living space, natural
disasters, predation, and unusual weather.
 Population – a group of individuals of the same species that live in the same area.
o A population is one of the levels of organization of the biosphere, the parts of Earth
where organisms live. The levels of biosphere organization from smallest to largest
are:
 Individual organism
 Population
 Community (all of the populations living in the same area)
 Ecosystem (a community and its non-living environment)
 Biome (a group of similar ecosystems)
 Biosphere
 Population density – the number of individuals in a population per unit of area.
o If 50 rabbits are living on a square kilometer of land, the population density would be
expressed as 50 rabbits/km2.
Lesson Overview
How does a population grow? What factors determine
whether a population will increase or decrease in size?
These are questions that students can explore with the
Rabbit Population by Season Gizmo™. Using this Gizmo,
students can simulate how two limiting factors—available
space and weather—can affect a population of rabbits.
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The Student Exploration sheet contains three activities:
 Activity A – Students describe the growth of a population of rabbits and determine the
carrying capacity of an environment.
 Activity B – Students explore the effects of a density-dependent limiting factor.
 Activity C – Students explore the effects of a density-independent limiting factor.
Suggested Lesson Sequence
1. Prior to using the Gizmo ( 10 – 15 minutes)
Before students are at the computers, pass out the Student Exploration sheets and ask students
to complete the Prior Knowledge Questions. Discuss student answers as a class, but do not
provide correct answers at this point. Afterwards, if possible, use a projector to introduce the
Gizmo and demonstrate its basic operations. Demonstrate how to take a screenshot and paste
the image into a blank document.
2. Gizmo activities ( 15 – 20 minutes per activity)
Assign students to computers. Students can work individually or in small groups. Ask students
to work through the activities in the Student Exploration using the Gizmo. Alternatively, you can
use a projector and do the Exploration as a teacher-led activity.
3. Discussion questions ( 15 – 30 minutes)
As students are working or just after they are done, discuss the following questions:
 What factors would cause the rabbit population to grow?
 What is the relationship between an environment’s carrying capacity and its limiting
factors?
 What is the difference between density-dependent limiting factors and densityindependent limiting factors?
 What limiting factors aren’t included in the Gizmo? [food, predation, disease, etc.]
 Suppose two limiting factors—a limited food supply and competition for nesting sites—
were limiting a population’s growth. If the number of nesting sites suddenly increased,
would the population begin to grow? [Probably not because there still would not be
enough food to support a larger population.]
4. Follow-up activities: ( variable)
 Tree Census
Take students to the schoolyard or a local park where trees are growing. Mark off an area
and have the class count the number of trees in the area. Ask students whether they
think more trees could grow in the area. If the area is thickly forested, students will likely
respond that no more trees or only a few more trees could grow in the area. If the area
has only a few trees, students will likely respond that many more trees could grow in the
area.
Have students give you an estimate of how many more trees they think could grow in the
censused area. Then ask students to explain their response. What factors did they
consider when guessing the maximum number of trees that could grow in the area? For
example, did they consider space or available sunlight? Write the factors that students list
on the board. Explain that these factors are called limiting factors. Students will learn
more about limiting factors as they complete the Gizmo’s Student Exploration sheet.
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
Organize students into groups. Give each group two plastic cups, potting soil, a tray or
pan, and 15 bean seeds that have been soaked in water overnight (this will speed
germination). Instruct each group to make several small drainage holes in the bottom of
each cup. The groups should then label one cup “A” and the other cup “B.” Have students
fill each cup with potting soil. Next, they should plant three bean seeds in cup A, making
sure that each seed is covered by no more than 3 mm of soil. The other 12 bean seeds
should be planted in cup B. Instruct the groups to place the cups on their trays and water
both cups daily. The soil should stay moist, but not wet.
Have students observe the growth of the seedlings. Students should count the number of
seedlings every day for two weeks. Students should also take notes on the appearance
of the seedlings in each cup. At the end of two weeks, students will likely report that
several of the seedlings in cup B have died. In addition, the seedlings in cup A will
probably appear larger and healthier than the seedlings in cup B. Help students identify
the limiting factors [space, competition for water, competition for light, etc.] that caused
the differences they see and how these limiting factors affected the seedlings.
A fascinating real-world connection to this Gizmo is the invasive rabbit population in
Australia. Have your students research how rabbits were introduced, how they have
damaged the environment, and what the Australian government has attempted to do to
control their populations. See the Current Events Connection and Selected Web
Resources on the next page of this document for details.
Scientific Background
Every population follows predictable growth patterns. A population that has all of the resources it
needs will grow exponentially. When graphed, exponential growth produces a J-shaped curve.
In the real world, no population can grow exponentially for long because the resources in an
environment are finite. In addition, conditions in an environment may not always be conducive to
growth. Because of this, a population’s growth is retarded at some point by limiting factors.
Density-dependent limiting factors include competition (such as the competition for space or
food), predation, parasitism, communicable disease, and stress from overcrowding. Densityindependent limiting factors include unusual weather, such as harsh winters and droughts, and
natural disasters, such as fires.
As limiting factors begin to act on a population, its growth slows. This period is called the
deceleration phase of growth. Eventually, a population’s overall growth drops to zero. This
period is called the stable equilibrium phase. Carrying capacity is reached at this phase, so the
population’s size will remain stable unless any of the environment’s limiting factors are altered.
A growth pattern that includes an exponential growth phase, a deceleration phase, and a stable
equilibrium phase is known as logistic growth. Most populations in nature follow logistic growth.
When plotted on a graph, logistic growth produces an S-shaped curve, with the stable
equilibrium phase making up the top portion of the S shape.
Current Events Connection: Australia’s rabbit problem
Thomas Austin, a rancher who settled in Australia in 1831, was an avid rabbit hunter.
Unfortunately for him, there were no rabbits in Australia at the time. In 1859, Austin released 24
European rabbits on his ranch just outside of Melbourne. Because rabbits were not native to
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Australia, they had no natural predators or parasites to limit their growth. By 1920, Australia was
overrun by more than 10 billion rabbits!
The rabbits rapidly overgrazed Australia’s landscape. They also outcompeted native animals,
driving several of them into extinction. Australians first attempted to limit the growth of rabbit
population in the late 1800s by building anti-rabbit fences. The longest fence was 1,833 km
(1,139 mi) long, running all the way from the north coast to the south coast of the country.
However, before the fences were complete, a few rabbits had already made it across to the
other side. In 1950, Australia introduced a rabbit virus to control the population. About 99% of
the rabbits died from the disease, but in less than 10 years, a population of resistant rabbits had
begun to spread across the nation again. In 1995, the Australian government again introduced a
new virus, but as with the previous attempt, the rabbit population has already begun to recover.
Selected Web Resources
Population growth: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Populations2.html
Limiting factors: http://www.nhptv.org/NATUREWORKS/nwep12a.htm
Population growth models: http://www.otherwise.com/population/index.html
Population growth project: http://www.ciese.org/curriculum/popgrowthproj/
Rabbits in Australia: http://www.rabbitfreeaustralia.org.au/rabbit_problem.html
Related Gizmos:
Food Chain: http://www.explorelearning.com/gizmo/id?381
Estimating Population Size: http://www.explorelearning.com/gizmo/id?261
Prairie Ecosystem: http://www.explorelearning.com/gizmo/id?647
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Activity 2 - Rabbit Population by Season
Vocabulary: carrying capacity, density-dependent limiting factor, density-independent limiting
factor, limiting factor, population, population density
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
[Note: The purpose of these questions is to activate prior knowledge and get students thinking.
Students are not expected to know the answers to the Prior Knowledge Questions.]
1. Suppose you had a pet rabbit. What would the rabbit need to stay alive and healthy?
Answers will vary. [Pet rabbits need food, fresh water, a clean living space, and shelter from
the elements in order to stay alive and healthy.]
2. A female rabbit can give birth to over 40 baby rabbits a year. Suppose all of her offspring
survived and reproduced, all of their offspring survived and reproduced, and so on. If that
happened, in only eight years the mass of rabbits would exceed the mass of Earth!
So, why aren’t we overrun with rabbits? What keeps the rabbit population in check? Answers
will vary. [Various environmental factors, such as limited food resources, keep a rabbit
population from growing too large.]
Gizmo Warm-up
A population is a group of individuals of the same species
that live in the same area. The size of a population is
determined by many factors. In the Rabbit Population by
Season Gizmo™, you will see how different factors influence
how a rabbit population grows and changes.
1. Select the BAR CHART tab. What is the approximate size
of the initial rabbit population? 40 rabbits
2. Select the TABLE tab. Click Play (
simulation to run for one year.
), and allow the
A. In which season did the rabbit population increase the most? Spring
B. In which season did the rabbit population increase the least? Winter
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Part A: Carrying Capacity
Engage Question: What determines how large a population can grow?
1. Get the Gizmo ready:
 Click Reset (
).
2. Think about it: A limiting factor is any factor that controls the growth of a population. What
do you think are some of the limiting factors for the rabbit population? Answers will vary.
[Examples of limiting factors include competition, disease, living space, natural disasters,
predation, and unusual weather.]
3. Run Gizmo: Select the DESCRIPTION tab. Set the Simulation speed to Fast. Select the
GRAPH tab. Click Play, and allow the simulation to run for at least 10 years. (Note: You can
use the zoom controls on the right to see the whole graph.)
A. Describe how the rabbit population changed over the course of 10 years. Sample
answer: For the first four years, the rabbit population increased in size. For the next six
years, the rabbit population stayed approximately the same size.
B. What pattern did you see repeated every year? The rabbit population increased in size at
the beginning of the year (spring), and then decreased in size towards the end of the year
(winter).
C. How could you explain this pattern? Sample answer: The rabbits reproduce during the
parts of the year when resources, such as food, are plentiful, but when resources are
harder to find, such as during the winter, many of the rabbits die.
4. Analyze: The carrying capacity is the maximum number of individuals of a particular
species that an environment can support. All environments have carrying capacities.
A. What is this environment’s approximate carrying capacity for rabbits? (Note: Average the
summer and winter carrying capacities.) The exact carrying capacity will vary but should
be between 350 and 450 rabbits.
B. When did the rabbit population reach carrying capacity? Explain how you know. Sample
answer: The rabbits reached carrying capacity during the fourth year of the simulation.
After this year, the average size of the rabbit population does not change much.
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Part B: Density-dependent limiting factors
Introduction: Population density is the number of individuals in a population per unit of area.
Some limiting factors only affect a population when its density reaches a certain level. These
limiting factors are known as density-dependent limiting factors.
Engage Question: How does a density-dependent limiting factor affect carrying capacity?
1. Get the Gizmo ready:
 Click Reset.
 On the SIMULATION pane, make sure Ample is selected for the amount of LAND
available.
2. Think about it: What do you think some density-dependent limiting factors might be?
Answers will vary. [Examples of density-dependent limiting factors include predation,
competition, and contagious diseases.]
3. Predict: How do you think the amount of land available will affect the rabbit population?
Answers will vary.
4. Experiment: Use the Gizmo to find the carrying capacity with Ample, Moderate, and Little
land. List the carrying capacities below.
Ample: About 400
Moderate: About 300
Little: About 100
5. Analyze: How did the amount of space available to the rabbits affect how many individuals
the environment could support? As the amount of space decreased, so did the number of
rabbits the environment could support.
6. Infer: Why do you think limiting a population’s space decreases the carrying capacity? As the
amount of available land decreases, vital resources such as food, water, and living space will
decrease as well.
7. Challenge yourself: Other than space, what might be another density-dependent limiting
factor? Explain. Sample answer: A contagious disease would be a density-dependent
limiting factor. The disease would only be able to spread successfully through the population
if the density was high enough that rabbits often came in contact with each other.
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Part C: Density-independent limiting factors
Introduction: Not all limiting factors are related to a population’s density. Density-independent
limiting factors affect a population regardless of its size and density.
Engage Question: How do density-independent limiting factors affect how a population grows?
1. Get the Gizmo ready:
 Click Reset.
 On the SIMULATION pane, make sure Ample is selected for the amount of LAND
available.
2. Think about it: What do you think some density-independent limiting factors might be?
Answers will vary. [Examples of density-independent limiting factors include unusual weather
and natural disasters.]
3. Gather data: Click Play. Allow the population to reach carrying capacity. Click Pause (
).
Select the GRAPH tab and click the camera ( ) to take a snapshot of the graph. Paste the
snapshot into a blank document. Label the graph “Normal Weather.” Check student work.
4. Predict: How do you think a period of harsh winters will affect the rabbit population?
Predictions will vary.
5. Investigate: Click Reset. Select Harsh winter from the CONDITIONS listed on the
SIMULATION pane. Click Play, and observe the how the population changes over five
years. Paste a snapshot of the graph in your document. Label the graph “Harsh Winter.”
A. How does the Harsh Winter graph differ from the Normal Weather graph? The carrying
capacity is lower and there is a greater population decrease during the winter.
B. What do you think most likely caused the differences seen in the two graphs? The harsh
winter weather is difficult to survive, so more members of the population die during the
winter.
6. Predict: Rabbits reproduce in the spring. How do you think a period of cold springs will affect
the rabbit population? Predictions will vary.
7. Investigate: Deselect Harsh winter. Select Cold spring. Click Play, and observe the how
the population changes over a period of five years. Paste a snapshot of the graph in your
document and label the graph “Cold Spring.”
A. How does the Cold Spring graph differ from the Normal Weather graph? The carrying
capacity is lower and there is a smaller population increase during the spring.
B. What do you think most likely caused the differences seen in the two graphs? The cold
spring weather makes it difficult for the rabbits to reproduce as many new individuals in
the spring, which is the main breeding season for the rabbits.
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8. Predict: How do you think a period of hot summers will affect the rabbit population?
Predictions will vary.
9. Investigate: Deselect Cold spring. Select Hot summer. Click Play, and observe the how
the population changes over a period of five years. Paste a snapshot of the graph in your
document. Label the graph “Hot Summer.”
A. How does the Hot Summer graph differ from the Normal Weather graph? The carrying
capacity is lower, and the rabbit population shrinks instead of staying the same or
growing during the summer.
B. What do you think most likely caused the differences seen in the two graphs? During hot
summers, rabbits are stressed and are unable to reproduce. In addition, the weaker
individuals may not be able to survive higher than normal temperatures.
10. Think and discuss: Other than unusual weather, what might be another density-independent
limiting factor that could affect the rabbit population? If possible, discuss your answer with
your classmates and teacher. Sample answer: A natural disaster, such as a fire, would be
another density-independent limiting factor. The fire would endanger all of the rabbits living
in the environment, no matter how many rabbits were present at the time of the fire.
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Assessment – Rabbit Population by Season
1. During which season does the rabbit population increase most rapidly?
A.
B.
C.
D.
spring
summer
fall
winter
2. Which of the following conditions best match this graph?
A.
B.
C.
D.
normal conditions
hot summers
cold springs
harsh winters
3. Based on the graph below, what is the most likely explanation for what happened just before
the start of Year 13?
A.
B.
C.
D.
normal conditions
hot summer
cold spring
harsh winter
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4. Based on the graph below, what is the most likely explanation for what happened halfway
through Year 15?
A.
B.
C.
D.
A hot summer.
A harsh winter.
A sharp increase in land available.
A sharp decrease in land available.
5. Which of the following conditions will result in the lowest rabbit population?
A.
B.
C.
D.
ample land, cold springs
little land, normal conditions
moderate land, hot summers
ample land, harsh winters
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Teacher Guide 3 – Literacy in the Content Area
1. Print article Sea Lions Feasting on Threatened Salmon
http://www.scientificamerican.com/article.cfm?id=sea-lions-feasting-threatened-salmon
2. Ask students to read the text and choose one of the activities:
 Have students find evidence of problems and solutions by marking sentences and/or
paragraphs that explain a problem with a ‘P’ or a solution to the problem with an ‘S’.
 Have students read aloud or “jump in” reading. Read the article as a whole class
highlighting important sentences and vocabulary.
3. Have students complete the scaffold questions.
4. After completion of the notes or other active reading strategies, assign each group one of the
questions to present their and have a class discussion. You may assign the same question
to more than one group.
Activity 3 – Literacy in the Content Area
Sea Lions Feasting on Threatened Salmon
http://www.scientificamerican.com/article.cfm?id=sea-lions-feasting-threatened-salmon
Procedures:
The teacher will tell you to follow procedure 1 or 2:
1. Read the text and choose one of the activities:
a. Find evidence of problems and solutions by marking sentences and/or paragraphs
that explain a problem with a ‘P’ or a solution to the problem with an ‘S’.
b. Using read aloud or “jump in” reading highlight important sentences and vocabulary.
2. Complete the scaffold questions.
3. After completion of the notes or other active reading strategies, you will be assigned one
of the questions to present and have a class discussion.
Sea Lions Feasting on Threatened Salmon: Should conservationists stop the California
sea lions from eating threatened Columbia River salmon?
ByJessica Marshall and Nature magazine
This article is reproduced by Scientific American with
permission from the magazine Nature. The article was
first published on August 22, 2012.
What do you do when a charismatic marine mammal is
wreaking havoc by gorging on a threatened species
that humans also find delicious? That’s the awkward
problem faced by wildlife managers along the Columbia
River in Washington and Oregon states, where sea
lions have been congregating for the past decade to
feast on salmon waiting to climb the fish ladders at the
base of the Bonneville Dam on their spring voyage
upriver to spawn.
Image: Flickr/cw_anderson, Nature magazine
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To protect the Chinook salmon (Oncorhynchus tshawytscha) and steelhead (Oncorhynchus
mykiss) in the river, some of which are listed as threatened populations, in 2008 the states of
Washington and Oregon obtained permission from the National Oceanic and Atmospheric
Administration in Silver Spring, Maryland, to kill California sea lions (which are normally
protected) seen feeding repeatedly at the dam, after attempts to frighten the animals away
proved ineffective.
In response, the Humane Society of the United States, based in Washington DC, and others
filed a lawsuit to stop the practice and their legal challenges have continued. A US district court
in Portland, Oregon, is expected to hear full arguments for a final ruling in the next few weeks. In
the meantime, more than 40 California sea lions have been killed and 11 transferred to aquaria
and zoos.
Survey data collected by the US Army Corps of Engineers during the years of the cull show that
numbers of California sea lions (Zalophus californianus) are decreasing at the dam, along with
the amount of salmon they eat. The corps and others attribute this to the removal programme.
Muscling in
But the cull may have been too successful. Last year, the larger Steller sea lions (Eumetopias
jubatus), which arrived in earnest at the dam in 2005 and have returned in greater numbers
each year, outnumbered California sea lions for the first time and ate fully half of the predated
salmon.
“Part of this switch toward the Steller sea lion abundance may be due in part to success of the
removal programme,” said Doug Hatch of the Columbia River Inter-Tribal Fish Commission in
Portland, Oregon, speaking at a meeting of the American Fisheries Society in St Paul,
Minnesota this week.
The problem with this shift is that Steller sea lions are themselves listed as a threatened
species, meaning that 'hazing' — disturbing them with, for example, rubber bullets — is the only
option for dealing with them. But the eastern stock of Steller sea lions, which includes those at
Bonneville, is under review for delisting as threatened, so that protection may not last.
Counting the damage
A key issue is exactly how much the sea lions are affecting the salmon, particularly the species
that are listed as threatened. This is a difficult question to answer. Accurate numbers are
available from near the dam, where sea lions and the prey in their mouths can be counted
directly, but the dam is 235 kilometres from the mouth of the Columbia River and sea lions are
present patchily throughout this length.
Hatch’s best estimate is that sea lions take on average a little over 10% of the listed populations
annually between the dam and the ocean. He and his colleagues are tagging sea lions to
improve understanding of where the mammals go within the river and beyond.
The Humane Society says that the cull focuses on the wrong problem — sea lions — instead of
reducing the allowable fishing catch, improving habitat, and reducing losses from hydropower,
which it maintains are greater threats to the fish.
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Archaeological records suggest that sea lions are recent arrivals in the Columbia River, but
researchers are finding that the smorgasbord of oily fish is expanding more than their range.
“We have captured and handled the largest California sea lions anyone has ever touched,” says
Robin Brown, a marine mammal specialist at Oregon Fish and Wildlife in Corvallis. The biggest
weighed 658 kilograms, compared to a typical weight for a male of 200–400 kilograms. “This
Columbia river salmon seems to fatten them up bigger and better than anything we’ve ever
seen.”
Scaffold Questions
1. Which threatened species need protection from the sea lions?
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2. What is a solution to the problem?
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3. Which term best describes the sea lions migration? Emigration or Immigration? Explain.
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4. Salmon are carnivores and eat squid, zooplankton, and adult invertebrates. How will the
population of salmon’s prey be affected?
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Assessment - Literacy in the Content Area
Have each student respond to the question below on a half a sheet of paper and ensure they
turn it in to you before they leave:
“Complete this statement. Ecosystems change because…”
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ANTI-DISCRIMINATION POLICY
Federal and State Laws
The School Board of Miami-Dade County, Florida adheres to a policy of nondiscrimination in
employment and educational programs/activities and strives affirmatively to provide equal
opportunity for all as required by law:
Title VI of the Civil Rights Act of 1964 - prohibits discrimination on the basis of race, color,
religion, or national origin.
Title VII of the Civil Rights Act of 1964, as amended - prohibits discrimination in employment
on the basis of race, color, religion, gender, or national origin.
Title IX of the Educational Amendments of 1972 - prohibits discrimination on the basis of
gender.
Age Discrimination in Employment Act of 1967 (ADEA), as amended - prohibits
discrimination on the basis of age with respect to individuals who are at least 40.
The Equal Pay Act of 1963, as amended - prohibits gender discrimination in payment of wages
to women and men performing substantially equal work in the same establishment.
Section 504 of the Rehabilitation Act of 1973 - prohibits discrimination against the disabled.
Americans with Disabilities Act of 1990 (ADA) - prohibits discrimination against individuals
with disabilities in employment, public service, public accommodations and telecommunications.
The Family and Medical Leave Act of 1993 (FMLA) - requires covered employers to provide
up to 12 weeks of unpaid, job-protected leave to “eligible” employees for certain family and
medical reasons.
The Pregnancy Discrimination Act of 1978 - prohibits discrimination in employment on the
basis of pregnancy, childbirth, or related medical conditions.
Florida Educational Equity Act (FEEA) - prohibits discrimination on the basis of race, gender,
national origin, marital status, or handicap against a student or employee.
Florida Civil Rights Act of 1992 - secures for all individuals within the state freedom from
discrimination because of race, color, religion, sex, national origin, age, handicap, or marital
status.
Veterans are provided re-employment rights in accordance with P.L. 93-508 (Federal Law) and
Section 295.07 (Florida Statutes), which stipulates categorical preferences for employment.
Revised 9/2008