Recent declines in freshwater mussels highlight the need to have up-to-date information on the status ofpopulations

Anecdotal accounts from local landowners in the wind bighorn drainage suggest thatfatmucket populations may be declining as landowners report seeing fewer shells in their streams. Thisproject proposes to survey streams on BLM lands in the bighorn wind river drainage to assess theabundance and distribution of these mussels. Such surveys have not been done on BLM lands previously. We will survey for fatmucket by searching for shells on stream banks and snorkeling in streams to lookfor live individuals. We will retain shells of deceased individuals to assess age and measure growth. Wewill measure the size of live individuals to assess the age structure of the population and look for evidenceof recruitment. Results from this study will provide information on the only native mussel species in thewind bighorn river drainage. We will deliver a report to the BLM that details the locations andinformation gathered at all sites. We will also publish a manuscript with the results. This information isuseful for making management decisions to ensure that these mussels have healthy populations. Theintended beneficiaries are the BLM (information for making management decisions), other agencies andresearchers (broader understanding of native mussels in the western US) and the public (mussels supporthealthy aquatic ecosystems and recreational opportunities). There are no subrecipients involved in theproposed project.