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The Shifty Salmon of Auke Creek


David A. Tallmon
Department of Biology and Marine Biology
University of Alaska Southeast


Pacific salmon are culturally, ecologically, and economically important throughout their geographic range. They are also increasingly depleted and threatened with extinction. This interrupted case study in three parts focuses on issues surrounding migration of this keystone species and how its ecology appears to be impacted by climate change. The storyline follows a young Alaskan who takes a summer job working at a Pacific salmon weir (a fish counting facility) and learns about observed shifts in the migration timing of several species of Pacific salmon, trout, and char (all in the Salmonid family). A selection of recommended videos provides context (approximately 15 minutes total viewing time), and the questions at the end of each section can be addressed with different levels of sophistication depending on the background of students. Simple calculations provide students an opportunity to think about the effects of climate change on the development, physiology, ecological interactions and evolution of Pacific salmon. Students also consider experimental design and influences of human harvest on natural populations. The case is suitable for students in an AP high school or lower-level college general biology, ecology, or environmental science course.


  • Read, interpret, and convert into different units data from graphs.
  • Consider important differences between observational and experimental studies and the types of inferences (correlation vs. causation) that come from observational and experimental studies.
  • Describe some of the physiological effects of increased temperatures on ectotherms.
  • Describe some of the potential ecological, social, and economic impacts of changes in the timing of ecological events such as salmon migration.


Pacific salmon; migration timing; ecology; evolution; ecological interactions; experimental design; salmon

Topical Areas

Social issues

Educational Level

High school, Undergraduate lower division



Type / Methods




Subject Headings

Ecology  |   Evolutionary Biology  |   Natural Resource Management  |   Science (General)  |   Zoology  |  

Date Posted


Teaching Notes

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Answer Key

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The following video(s) are recommended for use in association with this case study.

  • Hinterland’s Who’s Who: Pacific Salmon
    Salmon life history is described, as well as their relationship to First Nations and declines in recent decades. Running time: 4:35 min. Produced by Canadian Wildlife Federation, 2017.
  • Salmon Sex and Death Sustains This Forest
    This video is Episode 11 of the series Wildlife with Bertie Gregory and explores how salmon and their mating cycles are integral to the ecosystem of Vancouver Island. Running time: 4:21 min. Produced by National Geographic Wild, 2016.
  • There’s Something Very Fishy About These Trees
    This episode of Deep Look, a short video series created by KQED San Francisco and presented by PBS Digital Studios, shows the perilous voyage of salmon upstream and how their deaths fertilize the soil and play an important role in a complex food web. Running time: 4:37 min. Produced by PBS, 2017.