Journal Article

Landscape Ecotoxicology of Coho Salmon Spawner Mortality in Urban Streams

Feist, Blake E., Davis, Jay W., Scholz, Nathaniel L., Buhle, Eric R., Arnold, Paul

2011

Overview

In the Pacific Northwest of the United States, adult coho salmon (Oncorhynchus kisutch) returning from the ocean to spawn in urban basins of the Puget Sound region have been prematurely dying at high rates (up to 90% of the total runs) for more than a decade. The current weight of evidence indicates that coho deaths are caused by toxic chemical contaminants in land-based runoff to urban streams during the fall spawning season. Non-point source pollution in urban landscapes typically originates from discrete urban and residential land use activities. In the present study we conducted a series of spatial analyses to identify correlations between land use and land cover (roadways, impervious surfaces, forests, etc.) and the magnitude of coho mortality in six streams with different drainage basin characteristics. We found that spawner mortality was most closely and positively correlated with the relative proportion of local roads, impervious surfaces, and commercial property within a basin. These and other correlated variables were used to identify unmonitored basins in the greater Seattle metropolitan area where recurrent coho spawner die-offs may be likely. This predictive map indicates a substantial geographic area of vulnerability for the Puget Sound coho population segment, a species of concern under the U.S. Endangered Species Act. Our spatial risk representation has numerous applications for urban growth management, coho conservation, and basin restoration (e.g., avoiding the unintentional creation of ecological traps). Moreover, the approach and tools are transferable to areas supporting coho throughout western North America.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Analysis / Animals / Basins / Biology / Chemical contaminants / Chemical pollution / Cities / Commercial real estate / Computer Science / Conservation / Conservation of Natural Resources - methods / Conservation of Natural Resources - statistics & numerical data / Contaminants / Correlation analysis / Creeks & streams / Deaths / Drainage / Drainage basins / Earth Sciences / Ecotoxicology / Ecotoxicology - methods / Endangered / Endangered Species / Environmental Monitoring - methods / Environmental Monitoring - statistics & numerical data / Environmental toxicology / Female / Fish / Fish Diseases - chemically induced / Fish Diseases - mortality / Fishes / Forests / Geography / Geospatial data / Habitats / Health aspects / Land cover / Land pollution / Land use / Landscape / Male / Metropolitan areas / Models, Biological / Mortality / Nonpoint source pollution / Northwestern United States / Ocean basins / Oncorhynchus kisutch / Oncorhynchus kisutch - physiology / Oncorhynchus mykiss / Point source pollution / Pollution / Recurrent / Reproduction - drug effects / Restoration / Risk management / Rivers - chemistry / Roads / Roads & highways / Runoff / Salmon / Salmonidae / Solea solea / Spatial analysis / Spawning / Streams / Survival Rate - trends / Urban areas / Urban development / Urban environments / Urban growth / Urban planning / Urban population / Urban runoff / Urban sprawl / Washington / Water Pollutants, Chemical - toxicity / Water pollution / Wildlife conservation