Meeting Abstract

68.7  Jan. 7  THE EFFECT OF BODY TEMPERATURE ON THE GROWTH AND MORTALITY OF GEUKENSIA DEMISSA JOST, JA*; HELMUTH, B; University of South Carolina jostj@biol.sc.edu

The ability to predict the effects of climate change on intertidal communities requires the ability to measure both the physiological limits of organisms in the laboratory and the actual body temperatures of these organisms in the field. Recent technology has allowed for great advances in the ability to measure body temperatures of organisms under field conditions, and using a physical model, I have documented spatial and temporal patterns in the body temperature of the Atlantic ribbed mussel, Geukensia demissa in a South Carolina estuary for a period of three years. Based on previous laboratory data, I suggested a lethal temperature for this species between 45 and 50°C. In order to examine the upper lethal temperature limit more closely, I exposed this species to temperatures of either 44, 46, 48, or 50°C in an incubator for 6 hours, followed by a 24 hour recovery period in a seawater holding tank. Preliminary results suggest the lethal temperature for 50% of the population is 47°C. In addition, I conducted a laboratory study to examine the potential effects of sublethal temperatures on mussel growth. Preliminary results suggest that an increase in daily maximum temperature results in a decrease in growth rate. These data imply that Geukensia demissa is negatively affected by temperatures that are currently occurring at a site within in its geographical range. Therefore, with the current predictions in climate change, there is the potential for mussel populations to experience an increase in mortality over time, ultimately leading to changes in salt marsh community structure.