This project explores the consequences of nutrient pollution in San Francisco Bay on two mud snails. One is an invasive species, Ilyanassa obsoleta; the other is the bay’s only native mud snail, Cerithidea californica. Findings to date suggest that nutrients, at low levels, are a resource to the snails because the nutrients feed microalgae upon which the snails graze. At higher levels, a transition occurs and nutrients become harmful to the animals. That at least is the theory being tested. In a separate but related study, the fellow observed a sudden rise in the number of Batillaria attramentaria (a relatively new invasive mud snail) and is now studying the causes and impacts of its population explosion; the effectiveness of different eradication methods and their environmental safety will be tested.