How does sea ice loss affect polar bear diets?

Karyn Rode, a wildlife biologist with the USGS, discusses sampling Arctic polar bears to learn more about the effects of sea ice loss on different populations.

Vocabulary: adaptation, sea ice, nutrition, population, climate change, ecological conditions, capture and recapture, isotopes

Next Generation Science Standards: LS2.C: Ecosystem Dynamics, Functioning, and Resilience, LS4.D: Biodiversity and Humans, ESS3.D: Global Climate Change, CC7: Stability and Change, CC2: Cause and Effect: Mechanism and Explanation. Can be used to build towards MS-LS2–1, MS-LS2–4, HS-LS2–1, HS-LS2–2, HS-LS2–6, and HS-ESS3–6.

Common Core State Standards: CCSS.ELA-LITERACY.RST.6–8.4, CCSS.ELA-LITERACY.RST.9–10.4, CCSS.ELA-LITERACY.RST.11–12.4

Polar bear with young, Arctic NWR. Credit: U.S. Fish and Wildlife Service Headquarters ( Public domain)

For USGS wildlife biologist Karyn Rode, tracking and tranquilizing polar bears from a helicopter are just the first thrilling steps in her research. After acquiring various samples from sleeping bears, Dr. Rode’s unique understanding of what they eat and how quickly they metabolize nutrients allows her to determine the condition of each bear. Working with a team of scientists from the US Fish and Wildlife Service for nearly a decade, Dr. Rode’s monitoring of polar bear health has helped reveal how well populations are adapting to the rapidly warming Arctic.

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Print video transcript.


  • These polar bears are the same species, Ursus maritimus. Why are there 19 different populations? Define the word population based on your idea.
  • Based on Dr. Rode’s information on the Chukchi Sea and the Beaufort Sea, why are the health conditions of the two populations so different? How is that connected to environmental conditions in the different areas?
  • Based on the video, what is catch and release? Why is this an important method of wildlife study?
  • Why do you think Dr. Rode compares wild polar bears to captive polar bears in zoos? How does that enrich her study of the wild polar bear populations?
  • Why do you think Dr. Rode assumes that cub survival in the Chukchi Sea indicates that richer food resources are available there? Explain why the two might be connected.
  • Draw a diagram that illustrated the differences in diet between the polar bears in the Chukchi Sea population and those in the Beaufort Sea population.

Activity Suggestions

  • This is just one of many stories that can be used to frame our discussion of climate change in the classroom while having students connect stories with data. Using this activity on illustrated graphs, have students use climate change data and art to promote awareness and understanding of issue, like sea ice loss and their connection to climate change. Share your students’ work and view the work of others on Instagram and Twitter with the hashtag #illustratedgraph.
  • In this data exploration activity from, have students dive into USGS ground tracking of polar bears and NASA satellite data on sea ice coverage in the South Beaufort Sea, Alaska.

Additional Resources

Listen to Dr. Karyn Rode and Luke Groskin talk more about Dr. Rode’s research and their recent trip to track and study polar bears.

Check out this video shot from the point-of-view (POV) of a polar bear.

Spring on the sea ice, polar bear point of view video on southern Beaufort Sea, USGS.