Dr. Bemis has over 15 years of experience in the study of aquatic ecosystems. He has participated extensively in many AMS efforts monitoring pollutants in water, sediment, and bivalve tissue. He currently serves as Project Manager for an investigation of mercury methylation processes at Dredged Material Placement sites in the California Delta on behalf of Ross Island Dredging and the US Army Corps of Engineers. He previously served as Assistant Project Manager for a California Bay-Delta Authority effort to investigate the causes of feminization of salmonid fish in California Delta rivers and a project for East Bay Municipal Utility District to conduct monitoring of wastewater blending discharges into San Francisco Bay during storm events. Additionally, he has assisted in culturing Corbicula clams for deployment in biosentinel studies to investigate possible wastewater sources of mercury in the Sacramento River.

Dr. Bemis has specialized expertise in investigating environmental problems using biogeochemical tracers, particularly stable isotopes. He previously helped to develop an isotopic 'fingerprint' approach to identify the source of carcinogenic disinfection byproducts (DBP) in drinking water supplied by the California Bay Delta. This method is being used by the USGS with the goal of reducing the source of DBP precursor compounds in the dissolved organic carbon pool delivered to water treatment plants. Also while at the USGS, Dr. Bemis investigated how the distribution of mercury in the ecosystem relates to spatial and temporal variations in food web structure and the production of bioavailable methylmercury. He also used biogeochemical measurements to test and help refine a model that describes seasonal ecosystem changes in the Everglades.