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Updated: Jul 6, 2026
07:41
Modeling the Size Spectrum for Macroinvertebrates and Fishes in Stream Ecosystems
Published on: July 30, 2019
Habitat saturation drives thresholds in stream subsidies
Jonathan W Moore1, Daniel E Schindler, Casey P Ruff
1School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington 98195, USA. jonathan.moore@noaa.gov
Ecology
|April 16, 2008
Summary
Salmon nest-digging behavior creates nonlinear subsidies to stream food webs. Increased salmon abundance disproportionately boosts egg availability, enhancing growth for resident fishes like trout.
Area of Science:
- Ecology
- Aquatic Ecosystems
- Trophic Dynamics
Background:
- Understanding how organism abundance affects ecosystems is key for nutrient transfer.
- Anadromous salmon play a crucial role in stream ecosystems.
Purpose of the Study:
- To examine how salmon territoriality and nest-digging influence trophic subsidies to stream fishes.
- To investigate the relationship between salmon density and egg availability for predators.
Main Methods:
- Developed an individual-based model of spawning salmon behavior.
- Conducted field studies in Alaskan streams to assess egg availability and fish diets.
- Utilized bioenergetics models to simulate trout growth rates.
Main Results:
- Salmon territoriality and habitat saturation led to nonlinear increases in available eggs with higher salmon densities.
- Increased salmon densities resulted in disproportionately more eggs in stream drift and in the diets of Arctic grayling and rainbow trout.
- Simulations showed significantly enhanced growth rates for trout due to salmon subsidies.
Conclusions:
- Small changes in salmon abundance can cause substantial shifts in stream food web subsidies.
- Behavioral impacts, like nonlinear subsidy generation, can exacerbate ecological consequences of keystone species population declines.
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