This story was originally published in the Fall 2011 UW SRP eBulletin.
Understanding how the environment can impact regional salmon survival is central to Dr. Evan Gallagher's research. One goal of his Superfund Research Program - Biotransformation Gene-environment Interactions in Salmon Neurotoxicity - is to understand how Superfund-identified chemicals interfere with the olfactory behavior of Coho salmon, an ecologically important species in the Pacific Northwest. Previous studies by NOAA researchers have shown that chemical 'injuries' to the olfactory system of salmon can impact key neurologically-controlled behaviors such as the ability to detect predators and prey as well as homing to native streams. Based on these observations, Dr. Gallagher's laboratory is investigating the mechanisms of how chemical exposures affect olfactory processes at the cellular level. His work is also generating molecular "biomarkers" of olfactory injury that can ultimately be used to evaluate areas of concern in the remediation of Superfund sites and also to assess the effects of cleanup processes.In addition to addressing the mechanisms of olfactory toxicity, another segment of Dr. Gallagher's research explores the ability of salmon to mount a protective olfactory system detoxification response during chemical exposures, and also trying to better understand the ramifications of exposures to mixtures of olfactory toxicants. Zebrafish, a well-defined genetic small fish laboratory model, are being used to better understand the mechanisms of olfactory injury of relevance to Pacific salmon. In the past year, new collaborations with salmon disease experts at the United States Geological Survey (USGS) are investigating the interplay between olfactory injury and immune suppression by cadmium, a model Superfund chemical of interest. Collectively, these studies in an ecologically relevant species (i.e. Coho salmon) while also using a small laboratory model (i.e. zebrafish) are uncovering how chemical exposures relevant to Superfund sites may affect the fitness and survival of Pacific salmon. The results of this research can help answer questions for agencies, fish managers, and scientists by providing a better grasp of how low-level chemical exposures may affect salmon survival.