Beginning to Study the Prevalence of Pathogens of the Blue Crab in the Northern Limit of Its Range

The world’s changing climate is expected to raise the temperature of southern New England waters by up to 4.5 ˚C in this century, to temperatures similar to the current mid-Atlantic region. This is expected to result in northward expansion of blue crab and other fishery species as well as of their pathogens. Using sensitive quantitative molecular methods, a coalition of academic, state and federal partners is beginning to assess the prevalence of two fatal pathogens of blue crab, a reovirus and a protozoan parasite, from Delaware Bay to the south shore of Massachusetts. After a successful first year, we have extended disease monitoring an additional year, in order to establish a 2 year timeline. Initial data has shown that both pathogens are at low prevalence in the northern limit of the blue crab range. However, separate research has shown that localized high prevalence events or “outbreaks” are also associated with warm waters. We would like to establish additional partnerships and funding to allow this survey to continue for an additional 3 years. This project can serve as a template for long-term studies of the effects of climate change and latitude on the prevalence of blue crab or other fishery species in the Northeast.