Shell Disease in American Lobster: Identification of Infection-Promoting Environmental Factors and Projections for an Expanding Epizootic

The American lobster (Homarus americanus) fishery is increasingly being degraded by the advancement of epizootic shell disease (ESD). Host susceptibility has been hypothesized to be related to increases in environmentally-induced physiological stress. Our research uses generalized additive models informed by more than three decades of biotic and environmental data to determine the relative importance of a variety of putative stressors on ESD prevalence. Preliminary results indicate several variables linked to climate change (e.g., bottom temperature and salinity) may significantly influence ESD distribution. Once completed, our model will be used in conjunction with climate projections to examine the likelihood of continued disease expansion into the Gulf of Maine, which contains the region’s most lucrative lobster fishery. Project findings will be published using a user-configurable, web-based mapping application that allows resource stakeholders to explore the historic and contemporary data related to ESD. By identifying the likely drivers of ESD prevalence and presenting that information in a user-accessible format, this research will provide an outlet for monitoring current and project future ESD distribution. We will present detailed model results along with a prototype web-based application to engage researchers and research managers in discussions on ESD in American lobster.