Effective conservation of a taxonomic group requires the identification of the fundamental requirements that allow it to persist and factors best suited to predict its distribution. Freshwater mussels are among the most imperiled taxa in the United States. The unique life history and habitat requirements of unionid mussels complicate efforts to model their distributions, an obstacle to mussel conservation. Given limited resources, a strategic approach including these factors to describe mussel requirements and spatially-explicit identification of threats will improve effectiveness and lower cost of mussel conservation and monitoring programs.

In this dissertation, I review existing knowledge regarding mussel ecology, how this information has influenced modeling successes and failures in the past, a consensus of the importance of physical stream characteristics and their impacts on mussel distributions, and limitations to mussel monitoring and modeling, concluding with an approach to mussel conservation to address limitations and complications.

Finally, I outline a two-part study that follows this approach and is part of a long-term mussel monitoring and conservation program in Missouri. The overarching goal of this study is to spatially describe the status and risks to mussel communities in the species-rich Meramec River Drainage. Elucidating relationships between community metrics (e.g., species richness) within otherwise fundamentally suitable habitats helps to inform management and pinpoint threats to mussel communities. Information on threats to mussels gained through this process is used to categorize reaches suitable for mussel communities, with conservation prioritization as the focus. Monitoring suggestions tailored to these categories are provided, and areas of potential reintroduction and restoration are identified. The results of this project provide information for managers on where mussel strongholds occur, why mussels are not present in areas that are otherwise fundamentally suitable, what threats affect mussel communities, and what monitoring strategies will efficiently track mussel communities through time.