A Sensory System at the Interface Between Stormwater Runoff and Salmon Survival
Nat Scholz, Research Zoologist, NOAA Fisheries, Northwest Fisheries Science Center, Seattle, WA
10 Feb 2006
Urbanization and other forms of human population growth are increasingly threatening aquatic species in coastal environments. Motor vehicles are a source of toxic contaminants such as copper, a metal that originates from vehicle exhaust and brake pad wear. Copper and other pollutants are deposited on roads and other impervious surfaces and then transported to aquatic habitats via Stormwater runoff. In the western United States, exposure to dissolved-phase copper is a particular concern for many populations of threatened and endangered Pacific salmon (Oncorhynchus spp.) that spawn and rear in coastal watersheds and estuaries. This presentation will explore the neurobehavioral effects of dissolved copper on the olfactory and lateral line systems of fish, including juvenile coho salmon (O. kisutch). More specifically, we show that copper is cytotoxic to sensory neurons following low, environmentally-realistic exposures. Moreover, dissolved copper interferes with the propagation of sensory information from receptor neurons to central brain networks. Finally, copper renders juvenile salmon insensitive to environmental signals (predation cues) that ultimately influence the predator-prey dynamics of wild populations. As the example of copper indicates, it will be necessary to link multiple scales of biological organization to address the impacts of non-point source pollution on threatened or endangered species. [This research is sponsored by the NOAA Coastal Storms Program.]