Freshwater mussels of the family Unionidae in North America have been in decline for at least the past 150 years. Major causes behind the decline are thought to be related to alteration or loss of habitat. Recent efforts by researchers have focused on understanding habitat associations of mussels so that more effective conservation efforts can be applied. Recent studies have identified variables that limit mussel community distributions. These variables are a combination of substrate and hydraulic variables that are associated with substrate stability. Furthermore, recent studies have suggested mussel studies are most informative at larger spatial scales and at high flow conditions. In this study, I set out to identify the preferred habitats of both an unsculptured mussel and a sculptured mussel at high flow to determine if species-specific differences such as shell morphology were important in habitat preference. I also examined this question at three different spatial scales to determine what spatial scale was the best at providing the most information about the habitat selection of these two species. Of the three spatial scales, the geomorphologically derived transect level exhibited the highest correlations between the sculptured mussel abundance and density and variables associated with substrate stability. Particularly, variables such as shear stress, Reynolds number, and mean particle size were among the strongest correlations with abundance and density. The analyses also suggested that the unsculptured mussel was more of a habitat generalist. The results of this study suggest that examining habitat associations at the species level may be more appropriate than at the community level. Studying only overall mussel communities can present issues in applied conservation as the focus is often on individual species rather than communities in general. Furthermore, the results suggest that grouping mussels by shell morphology may be an appropriate starting point for conservation applications.
Date of publication
Goodding, Daniel, "Influence of Substrate and Hydraulic Variables on Habitat Preferences of a Sculptured and an Unsculptured Freshwater Mussel" (2012). Biology Theses. Paper 14.