This layer represents fundamentally suitable and unsuitable habitat for freshwater mussels in the Meramec Basin as modeled by these authors on May 17, 2017 based on spatial data ranging from 1990 to 2014. Identification of habitat characteristics associated with the presence of freshwater mussels is challenging but crucial for the conservation of this declining fauna. Most mussel species are found in multi-species assemblages suggesting that physical factors influence presence similarly across species. In lotic environments, geomorphic and hydraulic characteristics appear to be important factors for predicting mussel presence. We used maximum entropy (MaxEnt) modeling to evaluate hydrogeomorphic variables associated with mussel presence at a riverscape-scale along 530 river km of the Meramec River basin, USA. Mussel locations were obtained from an existing multi-year dataset, and hydrogeographic variables were derived using high-resolution, open-source datasets of aerial imagery and topography. The following hydrogeomorphic variables were associated with mussel presence: lateral channel stability, low-flow surface water availability, presence of gravel bars, and stream power, but presence of gravel bars appeared to be the most important variable. Identification of suitable habitat was strongly influenced by the distance to gravel bars, suggesting mussels are found near gravel bars. A subset of the data not used in model development was used to validate the final model. The validation locations fell almost exclusively and disproportionately in habitats that the model identified as suitable, suggesting that we identified common habitat requirements for multiple mussel species. These findings can inform how resource managers allocate survey, monitoring, and conservation efforts.
