Midwest Fish & Wildlife Conference 2018

AUTHORS. Megan C. Malish, Daelyn A. Woolnough - Central Michigan University Department of Biology and Institute for Great Lakes Research

ABSTRACT. Freshwater mussels (Bivalvia: Unionoida) serve vital roles in riverine communities but are made vulnerable by rising stream temperatures. We have examined the impact of mussel density and species richness on the thermal tolerance of two species of freshwater mussels, Lampsilis cardium and Amblema plicata. These species were chosen because they are ubiquitous, common, and have been found to vary in their thermal tolerance. Mussels were collected from the Grand River, Lyons, Michigan USA and were arranged in tanks in a 3 x 3 factorial design with varying densities and species combinations in 35L tanks within an environmental chamber. We measured clearance rate, respiration rate, and excretion of mussels at incrementally increasing temperatures relevant to the Great Lakes region and predictions made by the Intergovernmental Panel on Climate Change over 5 week periods. Water quality data (ammonia and total phosphorus) were collected for each tank at the beginning and end of the experiments to determine overall changes in water quality over the experimental periods. We will present our data that will aid in an improved understanding of how entire riverine ecosystems will change based on changes in ecosystem services provided by mussel communities. We can better focus conservation efforts of imperiled aquatic organisms by understanding how mussel communities respond to rising temperatures.