Question
Predicting Changes in Arctic Ecological
Communities
Part 1: Examining Data on Arctic Sea Ice Extent
Arctic sea ice, the layer of frozen seawater covering much of the
Arctic Ocean and neighboring seas, is often referred to as Earth’s
air conditioner: its white surface bounces solar energy back to
space, cooling the globe. The sea ice cap changes with the season,
growing in the autumn and winter and shrinking in the spring
and summer. Its minimum summertime extent (how much
surface area it covers), which typically occurs in September, has
been decreasing, overall, at a rapid pace since the late 1970s due
to warming temperatures.
3
4
5
6
7
8
1980 1985 1990 1995 2000 2005 2010 2015 2020
Sea ice minimum (million km2)
Year
Arctic sea ice minimum extent in September (1979−2019). (Text and graph adapted from “End-of-Summer
Arctic Sea Ice Extent Is Eighth Lowest on Record.” © 2019 by NASA.)
1. Calculate the percent change in the area of September Arctic sea ice extent
between 1980 and 2019.
2. Determine the average change in Arctic sea ice extent per decade.
BIO_U1_SR.indd 59 25/03/20 11:15 PM
Unit 1: Ecological Systems
Student Resource
© 2021 College Board
Pre-AP Biology 60
Lesson 1.11: Predicting Changes in Arctic Ecological Communities
HANDOUT
1.11.A
3. Predict which organisms may depend on Arctic sea ice.
Part 2: Making Predictions and Asking Scientific Questions
THE IMPORTANCE OF ARCTIC SEA ICE
You may remember from studying the carbon cycle that humans’ energy use has
contributed greatly to the amount of carbon dioxide found in the atmosphere.
According to NASA, “Humans have increased atmospheric CO2
concentration by more
than a third since the Industrial Revolution began. This is the most important longlived ‘forcing’ of climate change.” The warming of Earth’s global climate has negative
effects on Arctic sea ice extent and, consequently, on Arctic ecosystems.
Predators have a significant impact on the structure and stability of ecosystems. As
you previously learned, trophic cascades are ecological phenomena that occur when
predator populations affect the populations of species throughout their food webs,
controlling the size and behavior of prey populations. Trophic cascades significantly
impact resource availability, nutrient cycling, and, in turn, entire ecosystems. The area
of the Arctic that is seasonally covered with sea ice is rapidly changing. These changes
are having profound effects on predator populations, and the resulting trophic cascades
are changing the characteristics of life in the Arctic.
In the Arctic, sea ice provides critical habitat for numerous species. Predators such as
polar bears use sea ice as a platform for hunting seals and small whales. Polar bears
hunt by lying in wait at the edge of sea ice or near holes in sea ice until these marine
mammals risk exposing themselves to come up for air. Moreover, many seal species rely
on sea ice as a resting place and as a nursery for their young.
For some other species of marine mammal, sea ice serves as an obstacle, limiting
the amount of available habitat. Large whales that are too big to breathe through the
relatively small holes in sea ice, as well as whales with large dorsal fins that don’t fit
through the holes in sea ice, such as killer whales, cannot travel easily in an ocean
covered with ice. As sea ice decreases, the amount of habitat available to these predator
species increases, and can cause significant changes in trophic cascades.
BIO_U1_SR.indd 60 25/03/20 11:15 PM
Unit 1: Ecological Systems
Student Resource
© 2021 College Board
61 Pre-AP Biology
Lesson 1.11: Predicting Changes in Arctic Ecological Communities
SPECIES PREDICTIONS TABLE
Your teacher will give you and a partner a set of Arctic Species Informational Cards.
Read each card and work together to organize them so that you can refer back to them
to quickly get information. After you have organized your cards, use the information on
them to complete the table and questions about environmental change.
Species Sea Ice
Requirement
Change in
Sea Ice
Predicted Effect and Reasoning
Walrus Decrease Walrus populations will likely decline if the
area of sea ice decreases, due to the loss of
critical habitat.
Gray Whale Decrease
Ringed Seal Increase
Narwhal No change
Killer
Whale
Decrease
Polar Bear Increase
Polar Bear Decrease
Spotted Seal Decrease
HANDOUT
1.11.A
BIO_U1_SR.indd 61 25/03/20 11:15 PM
Unit 1: Ecological Systems
Student Resource
© 2021 College Board
Pre-AP Biology 62
Lesson 1.11: Predicting Changes in Arctic Ecological Communities
ASKING SCIENTIFIC QUESTIONS
1. Based on the change in sea ice area since 1980, make three predictions about how
the sea ice change has affected specific Arctic species.
2. Use data from the graph in Part 1 to predict the year in which ice-obligate species
were impacted the most?
3. State a scientific question, based on one of your predictions.
4. Identify the data that scientists would need to collect to answer your scientific
question.
5. What methods could scientists use to collect the data required to answer your
scientific question? Be specific.
6. Think about the city or state in which you live. If the area of your city or state
was substantially decreased, predict what would happen to you and your fellow
residents.
HANDOUT
1.11.A
BIO_U1_SR.indd 62 25/03/20 11:15 PM
Unit 1: Ecological Systems
Student Resource
© 2021 College Board
63 Pre-AP Biology
Lesson 1.11: Predicting Changes in Arctic Ecological Communities
HANDOUT Arctic Species Information Cards 1.11.B
Ice-obligate species rely on sea
ice as a platform for resting,
breeding, and/or hunting.
Ice-obligate species include polar
bear, walrus, bearded seal, and
ringed seal.
The capacity of ice-obligate
species to survive and reproduce
increases when the area and
thickness of sea ice increases.
Ice-associated species are
adapted to marine ecosystems
in which sea ice is a key part.
However, they rely less on sea ice
than do ice-obligate species.
Ice-associated species include
harp seal, hooded seal, ribbon
seal, spotted seal, beluga,
narwhal, and bowhead whale.
Populations of ice-associated
species are typically harmed
when the area and thickness of
sea ice decreases.
Seasonally migrant species come
across sea ice at some point
during the year due to their
seasonal movements. They do
not rely on sea ice for survival.
Seasonally migrant species
include fin whale, humpback
whale, minke whale, gray whale,
and killer whale.
Populations of seasonally
migrant species are likely to
benefit when the area and
thickness of sea ice decreases.
This is due to the resulting
increase in access to the openocean ecosystems in which the
Communities
Part 1: Examining Data on Arctic Sea Ice Extent
Arctic sea ice, the layer of frozen seawater covering much of the
Arctic Ocean and neighboring seas, is often referred to as Earth’s
air conditioner: its white surface bounces solar energy back to
space, cooling the globe. The sea ice cap changes with the season,
growing in the autumn and winter and shrinking in the spring
and summer. Its minimum summertime extent (how much
surface area it covers), which typically occurs in September, has
been decreasing, overall, at a rapid pace since the late 1970s due
to warming temperatures.
3
4
5
6
7
8
1980 1985 1990 1995 2000 2005 2010 2015 2020
Sea ice minimum (million km2)
Year
Arctic sea ice minimum extent in September (1979−2019). (Text and graph adapted from “End-of-Summer
Arctic Sea Ice Extent Is Eighth Lowest on Record.” © 2019 by NASA.)
1. Calculate the percent change in the area of September Arctic sea ice extent
between 1980 and 2019.
2. Determine the average change in Arctic sea ice extent per decade.
BIO_U1_SR.indd 59 25/03/20 11:15 PM
Unit 1: Ecological Systems
Student Resource
© 2021 College Board
Pre-AP Biology 60
Lesson 1.11: Predicting Changes in Arctic Ecological Communities
HANDOUT
1.11.A
3. Predict which organisms may depend on Arctic sea ice.
Part 2: Making Predictions and Asking Scientific Questions
THE IMPORTANCE OF ARCTIC SEA ICE
You may remember from studying the carbon cycle that humans’ energy use has
contributed greatly to the amount of carbon dioxide found in the atmosphere.
According to NASA, “Humans have increased atmospheric CO2
concentration by more
than a third since the Industrial Revolution began. This is the most important longlived ‘forcing’ of climate change.” The warming of Earth’s global climate has negative
effects on Arctic sea ice extent and, consequently, on Arctic ecosystems.
Predators have a significant impact on the structure and stability of ecosystems. As
you previously learned, trophic cascades are ecological phenomena that occur when
predator populations affect the populations of species throughout their food webs,
controlling the size and behavior of prey populations. Trophic cascades significantly
impact resource availability, nutrient cycling, and, in turn, entire ecosystems. The area
of the Arctic that is seasonally covered with sea ice is rapidly changing. These changes
are having profound effects on predator populations, and the resulting trophic cascades
are changing the characteristics of life in the Arctic.
In the Arctic, sea ice provides critical habitat for numerous species. Predators such as
polar bears use sea ice as a platform for hunting seals and small whales. Polar bears
hunt by lying in wait at the edge of sea ice or near holes in sea ice until these marine
mammals risk exposing themselves to come up for air. Moreover, many seal species rely
on sea ice as a resting place and as a nursery for their young.
For some other species of marine mammal, sea ice serves as an obstacle, limiting
the amount of available habitat. Large whales that are too big to breathe through the
relatively small holes in sea ice, as well as whales with large dorsal fins that don’t fit
through the holes in sea ice, such as killer whales, cannot travel easily in an ocean
covered with ice. As sea ice decreases, the amount of habitat available to these predator
species increases, and can cause significant changes in trophic cascades.
BIO_U1_SR.indd 60 25/03/20 11:15 PM
Unit 1: Ecological Systems
Student Resource
© 2021 College Board
61 Pre-AP Biology
Lesson 1.11: Predicting Changes in Arctic Ecological Communities
SPECIES PREDICTIONS TABLE
Your teacher will give you and a partner a set of Arctic Species Informational Cards.
Read each card and work together to organize them so that you can refer back to them
to quickly get information. After you have organized your cards, use the information on
them to complete the table and questions about environmental change.
Species Sea Ice
Requirement
Change in
Sea Ice
Predicted Effect and Reasoning
Walrus Decrease Walrus populations will likely decline if the
area of sea ice decreases, due to the loss of
critical habitat.
Gray Whale Decrease
Ringed Seal Increase
Narwhal No change
Killer
Whale
Decrease
Polar Bear Increase
Polar Bear Decrease
Spotted Seal Decrease
HANDOUT
1.11.A
BIO_U1_SR.indd 61 25/03/20 11:15 PM
Unit 1: Ecological Systems
Student Resource
© 2021 College Board
Pre-AP Biology 62
Lesson 1.11: Predicting Changes in Arctic Ecological Communities
ASKING SCIENTIFIC QUESTIONS
1. Based on the change in sea ice area since 1980, make three predictions about how
the sea ice change has affected specific Arctic species.
2. Use data from the graph in Part 1 to predict the year in which ice-obligate species
were impacted the most?
3. State a scientific question, based on one of your predictions.
4. Identify the data that scientists would need to collect to answer your scientific
question.
5. What methods could scientists use to collect the data required to answer your
scientific question? Be specific.
6. Think about the city or state in which you live. If the area of your city or state
was substantially decreased, predict what would happen to you and your fellow
residents.
HANDOUT
1.11.A
BIO_U1_SR.indd 62 25/03/20 11:15 PM
Unit 1: Ecological Systems
Student Resource
© 2021 College Board
63 Pre-AP Biology
Lesson 1.11: Predicting Changes in Arctic Ecological Communities
HANDOUT Arctic Species Information Cards 1.11.B
Ice-obligate species rely on sea
ice as a platform for resting,
breeding, and/or hunting.
Ice-obligate species include polar
bear, walrus, bearded seal, and
ringed seal.
The capacity of ice-obligate
species to survive and reproduce
increases when the area and
thickness of sea ice increases.
Ice-associated species are
adapted to marine ecosystems
in which sea ice is a key part.
However, they rely less on sea ice
than do ice-obligate species.
Ice-associated species include
harp seal, hooded seal, ribbon
seal, spotted seal, beluga,
narwhal, and bowhead whale.
Populations of ice-associated
species are typically harmed
when the area and thickness of
sea ice decreases.
Seasonally migrant species come
across sea ice at some point
during the year due to their
seasonal movements. They do
not rely on sea ice for survival.
Seasonally migrant species
include fin whale, humpback
whale, minke whale, gray whale,
and killer whale.
Populations of seasonally
migrant species are likely to
benefit when the area and
thickness of sea ice decreases.
This is due to the resulting
increase in access to the openocean ecosystems in which the
Answers
GPT-4o mini
### Part 1: Examining Data on Arctic Sea Ice Extent
#### 1. Calculate the percent change in the area of September Arctic sea ice extent between 1980 and 2019.
To calculate the percent change, you can use the formula:
\[
\text{Percent Change} = \left(\frac{\text{Final Value} - \text{Initial Value}}{\text{Initial Value}}\right) \times 100
\]
Assuming you have the values for the sea ice extent in 1980 and 2019 from the graph (let's say the extent in 1980 was 7.0 million km² and in 2019 it was 4.3 million km²), the calculation would look like:
\[
\text{Percent Change} = \left(\frac{4.3 - 7.0}{7.0}\right) \times 100 = \left(\frac{-2.7}{7.0}\right) \times 100 \approx -38.57\%
\]
This indicates a decrease of approximately **38.57%** in September Arctic sea ice extent between 1980 and 2019.
#### 2. Determine the average change in Arctic sea ice extent per decade.
To determine the average change per decade, first find the total change over the years before dividing by the number of decades.
If we assume the extent was 7.0 million km² in 1980 and 4.3 million km² in 2019:
\[
\text{Total Change} = 4.3 \text{ million km}^2 - 7.0 \text{ million km}^2 = -2.7 \text{ million km}^2
\]
There are **39 years** from 1980 to 2019, or roughly **3.9 decades**.
\[
\text{Average Change per Decade} = \frac{-2.7 \text{ million km}^2}{3.9} \approx -0.692 \text{ million km}^2 \text{ per decade}
\]
### Part 2: Making Predictions and Asking Scientific Questions
#### 1. Based on the change in sea ice area since 1980, make three predictions about how the sea ice change has affected specific Arctic species.
1. **Polar Bears**: With the decrease in sea ice, polar bear populations may decline because they rely on ice as a platform for hunting seals.
2. **Walruses**: Walrus populations might also decline, as less sea ice means less habitat for resting and breeding.
3. **Killer Whales**: The number of killer whales may increase, as the reduction of sea ice allows them greater access to hunting grounds previously obstructed by ice.
#### 2. Use data from the graph in Part 1 to predict the year in which ice-obligate species were impacted the most.
Ice-obligate species likely experience the most significant impacts during the years with the lowest September sea ice extent. Based on the data in the abstract, the year **2012** could be associated with one of the lowest sea ice extents, leading to the most significant impact on these species.
#### 3. State a scientific question, based on one of your predictions.
**Question**: How has the decline in Arctic sea ice extent since 1980 affected the population dynamics of polar bears in the Arctic?
#### 4. Identify the data that scientists would need to collect to answer your scientific question.
- Historical population data of polar bears from 1980 to present.
- Data on sea ice extent for the same time period.
- Data on seal populations, which serve as the primary food source for polar bears.
- Climate data indicating changes in temperature and ice thickness.
#### 5. What methods could scientists use to collect the data required to answer your scientific question? Be specific.
1. **Field Surveys**: Conduct surveys of polar bear populations and their movements using GPS collars and remote sensing technology.
2. **Satellite Imagery**: Use satellite data to track changes in sea ice extent and thickness over time.
3. **Ecological Modeling**: Develop ecological models to establish correlations between polar bear population dynamics and changes in sea ice and prey availability.
4. **Long-term Monitoring Programs**: Collaborate with established wildlife monitoring programs to gather continuous data on polar bear health, reproduction, and survival rates.
#### 6. Think about the city or state in which you live. If the area of your city or state was substantially decreased, predict what would happen to you and your fellow residents.
If the area of my city/state were to substantially decrease, residents might experience several consequences, including:
1. **Increased Population Density**: Overcrowding in the remaining area, leading to potential housing shortages and increased cost of living.
2. **Economic Strain**: Businesses may struggle to accommodate more customers, affecting employment opportunities and economic stability.
3. **Access to Resources**: Limited access to natural resources, parks, and recreational areas might lead to a decline in quality of life, affecting mental and physical health.
4. **Transport and Infrastructure Issues**: Strain on existing transportation and infrastructure systems due to increased demand could lead to traffic congestion and decreased quality of public services.
These predicted changes emphasize the interconnectedness of ecosystem health and human societal dynamics.
#### 1. Calculate the percent change in the area of September Arctic sea ice extent between 1980 and 2019.
To calculate the percent change, you can use the formula:
\[
\text{Percent Change} = \left(\frac{\text{Final Value} - \text{Initial Value}}{\text{Initial Value}}\right) \times 100
\]
Assuming you have the values for the sea ice extent in 1980 and 2019 from the graph (let's say the extent in 1980 was 7.0 million km² and in 2019 it was 4.3 million km²), the calculation would look like:
\[
\text{Percent Change} = \left(\frac{4.3 - 7.0}{7.0}\right) \times 100 = \left(\frac{-2.7}{7.0}\right) \times 100 \approx -38.57\%
\]
This indicates a decrease of approximately **38.57%** in September Arctic sea ice extent between 1980 and 2019.
#### 2. Determine the average change in Arctic sea ice extent per decade.
To determine the average change per decade, first find the total change over the years before dividing by the number of decades.
If we assume the extent was 7.0 million km² in 1980 and 4.3 million km² in 2019:
\[
\text{Total Change} = 4.3 \text{ million km}^2 - 7.0 \text{ million km}^2 = -2.7 \text{ million km}^2
\]
There are **39 years** from 1980 to 2019, or roughly **3.9 decades**.
\[
\text{Average Change per Decade} = \frac{-2.7 \text{ million km}^2}{3.9} \approx -0.692 \text{ million km}^2 \text{ per decade}
\]
### Part 2: Making Predictions and Asking Scientific Questions
#### 1. Based on the change in sea ice area since 1980, make three predictions about how the sea ice change has affected specific Arctic species.
1. **Polar Bears**: With the decrease in sea ice, polar bear populations may decline because they rely on ice as a platform for hunting seals.
2. **Walruses**: Walrus populations might also decline, as less sea ice means less habitat for resting and breeding.
3. **Killer Whales**: The number of killer whales may increase, as the reduction of sea ice allows them greater access to hunting grounds previously obstructed by ice.
#### 2. Use data from the graph in Part 1 to predict the year in which ice-obligate species were impacted the most.
Ice-obligate species likely experience the most significant impacts during the years with the lowest September sea ice extent. Based on the data in the abstract, the year **2012** could be associated with one of the lowest sea ice extents, leading to the most significant impact on these species.
#### 3. State a scientific question, based on one of your predictions.
**Question**: How has the decline in Arctic sea ice extent since 1980 affected the population dynamics of polar bears in the Arctic?
#### 4. Identify the data that scientists would need to collect to answer your scientific question.
- Historical population data of polar bears from 1980 to present.
- Data on sea ice extent for the same time period.
- Data on seal populations, which serve as the primary food source for polar bears.
- Climate data indicating changes in temperature and ice thickness.
#### 5. What methods could scientists use to collect the data required to answer your scientific question? Be specific.
1. **Field Surveys**: Conduct surveys of polar bear populations and their movements using GPS collars and remote sensing technology.
2. **Satellite Imagery**: Use satellite data to track changes in sea ice extent and thickness over time.
3. **Ecological Modeling**: Develop ecological models to establish correlations between polar bear population dynamics and changes in sea ice and prey availability.
4. **Long-term Monitoring Programs**: Collaborate with established wildlife monitoring programs to gather continuous data on polar bear health, reproduction, and survival rates.
#### 6. Think about the city or state in which you live. If the area of your city or state was substantially decreased, predict what would happen to you and your fellow residents.
If the area of my city/state were to substantially decrease, residents might experience several consequences, including:
1. **Increased Population Density**: Overcrowding in the remaining area, leading to potential housing shortages and increased cost of living.
2. **Economic Strain**: Businesses may struggle to accommodate more customers, affecting employment opportunities and economic stability.
3. **Access to Resources**: Limited access to natural resources, parks, and recreational areas might lead to a decline in quality of life, affecting mental and physical health.
4. **Transport and Infrastructure Issues**: Strain on existing transportation and infrastructure systems due to increased demand could lead to traffic congestion and decreased quality of public services.
These predicted changes emphasize the interconnectedness of ecosystem health and human societal dynamics.