Will Climate Change Help New York Hard Clams Fight Disease?

Warming trends will progress along with increased precipitation, particularly during winter and spring, in projections of climate change for the Northeastern US. Hard clams suffered significantly from QPX disease under cool water (13°C) laboratory treatments compared to warm water treatments (21°C and 27°C). Coastal New York (NY) waters are expected to experience more days of temperatures above 21°C. QPX related hard clam mortalities in the lab were greater under high (30ppt) vs low (17ppt) salinity treatments and in vitro studies have shown QPX growth to be inhibited by low salinities. Increased precipitation to watersheds and heavier river flow will alter estuarine salinity regimes that could restrict the distribution of QPX in hard clam habitats. Analysis of over ten years of infection and environmental monitoring data from Raritan Bay, a QPX enzootic estuary, reveals areas of lower salinity and higher summer temperatures have limited QPX infections. Climate change is often considered a source of potential stressors to marine organisms that increases their susceptibility to physiological ailments and opportunistic disease. In this particular scenario of QPX disease in NY coastal waters, climate change may become more detrimental to this specific opportunistic pathogen and could benefit the health of hard clam populations.