Nat is a marine biologist and zoologist by training. He has managed the multidisciplinary Ecotoxicology Program at the Nortwest Fisheries Science Center since 2004. He joined the Center in 1998 as a Postdoctoral Associate with the National Academies of Science and Engineering (National Research Council) after completing a doctorate in zoology from the University of Washington. Prior to that he did masters and undergraduate research in Boston University's Marine Program in Woods Hole. He has published widely on the ecological impacts of freshwater and marine pollution, at scales ranging from gene expression to the dynamics of wild fish populations.