THE RESPONSE OF FRESHWATER MUSSELS TO BEDLOAD TRANSPORT: EXPERIMENTAL STREAM STUDIES
Habitat modification is believed to be one of the major causes of freshwater mussel decline. Mussel abundance and distribution is inherently linked with their habitat through sediment transport processes in moving waters (i.e. suspended sediment or bed stability). We examined bedload transport impacts on mussels through a series of four experiments at the University of Minnesota Outdoor StreamLab. The experiments included: 1. Comparing mussel movement between 3 species of mussel under quasi-equilibrium bedload conditions. 2. Comparing impact of mussel density on substrate stability 3. Comparing bed topography impact on mussel movement, and 4. Comparing burrowing under aggrading and degrading bedloads. We found that all species moved little under flooding conditions, but relocate to deeper water after a flood. At modest levels of mussel density there was little impact of mussels on substrate stability. When bottom topography is flat mussel movement is non-directional. With sloped bottoms, mussels move to deeper locations. Mussels exposed to an aggrading flood emerge from the sediment within one day. Those exposed to a degrading flood burrow into the bottom especially if the sediment is fine.
Dan Hornbach (Primary Presenter/Author), Macalester College, firstname.lastname@example.org;
Mark Hove ( Co-Presenter/Co-Author), University of Minnesota, email@example.com;
Kelly MacGregor ( Co-Presenter/Co-Author), Macalester College, firstname.lastname@example.org;
Jessica Kozarek ( Co-Presenter/Co-Author), St. Anthony Falls Laboratory, University of Minnesota, email@example.com;