Meeting Abstract

P2.133  Jan. 5  The Effect of Food Availability and Intertidal Body Temperature on Blue Mussels VAN THIEL, L.E.*; SCHNEIDER, K.R.; HELMUTH, B.; University of South Carolina, Columbia; University of South Carolina, Columbia; University of South Carolina, Columbia vanthiel@mailbox.sc.edu

The interactive effects of temperature and food availability can greatly affect the survival and physiological performance of organisms, and predicting the effects of these variables of species distributions is essential in the face of global climate change. The rocky intertidal zone is ideal to study these interactive effects because organisms are cyclically exposed to both marine and terrestrial conditions. In this study we examined the synergistic effects of intertidal thermal stress (aerial body temperature) and food availability on the life history of two species of blue mussel of the Mytilus edulis complex, M. trossulus and M. galloprovincialis. These two species form a hybrid zone along the west coast of the United States where M. galloprovincialis is an invasive species, displacing or replacing M. trossulus. Mussels of both species were exposed to tidal regimes with varying aerial body temperatures (20°, 25°, 30° and subtidal) and 2 feeding regimes (low and high). Growth and survival were monitored for nine weeks on a regular basis. Results show warmer aerial body temperatures have a greater effect on the fitness of both species, regardless of food availability. However, mortality with low food was greater and happened more rapidly than in the high food treatment. There were statistically significant differences in survival among the thermal treatments in both tanks however; differences in species specific mortality were only significant within the tank with high food availability. By studying the effect of thermal stress as well as food availability, our goal is to form a more complete forecast of the effects that global climate change may have on the distributions of native and invasive species.