Projections of the future occurrence, distribution, and seasonality of three species in the Chesapeake Bay under a high-emission climate change scenario.

Illness caused by pathogenic strains of bacteria incurs significant economic and health care costs in many areas around the world. In the Chesapeake Bay, the two most problematic species are . and . , which cause infection both from exposure to contaminated water and consumption of contaminated seafood. We used existing habitat models, four global climate models, and a recently developed statistical downscaling framework to project the spatiotemporal probability of occurrence of . and . in the estuarine environment, and the mean concentration of . in oysters in the Chesapeake Bay by the end of the 21st century. Results showed substantial future increases in season length and spatial habitat for . and . , while projected increase in . habitat was less marked and more spatially heterogeneous. Our findings underscore the need for spatially variable inputs into models of climate impacts on in estuarine environments. Overall, economic costs associated with in the Chesapeake Bay, such as incidence of illness and management measures on the shellfish industry, may increase under climate change, with implications for recreational and commercial uses of the ecosystem.