Invasive species are a growing global concern because of their negative impacts on ecosystem functions and biodiversity. American shad are an andaromous (ascend rivers from the ocean to spawn) fish native to the Atlantic coast of North America that were deliberately introduced to the Sacramento River, CA, in 1871. The species has now spread to additional Pacific coastal rivers, and have dramatically increased in abundance in the some systems like the Columbia River.

Despite their prevelance in the Pacific northwest, basic information about the ecological effects of shad on native species remain unknown. A first step towards gaining an understanding of the species impacts requires knowing where they continue to be found.