Ever increasing fragmentation and habitat loss poses significant threats to the connectivity of aquatic organisms across the biodiversity hotspot of the southeastern united states

The Department of the Interior Fish and Wildlife Service awarded a $201,905 Project Grant to The University of Southern Mississippi under the Fish and Wildlife Management Assistance program (CFDA 15.608). This funding supports efforts to conserve and restore aquatic connectivity in the Southeast U.S. biodiversity hotspot by assessing barriers to aquatic species movement and utilizing genetic tools to prioritize barrier removal. The work enhances an ongoing recovery project for the federally threatened Louisiana pearlshell mussel, aiming to validate the use of conservation genomics to measure stream network connectivity and identify host fish species. This research will inform future management and restoration efforts for the mussel species.

Conserving and restoring connectivity within riverscapes by removing barriers to aquatic species movement is one of the most cost-efficient ways to restore proper ecological function. Restoring aquatic connectivity over small stream reaches or river segments has limited value in most instances, so managers and scientists have invested more resources in recent decades to build spatial tools that evaluate benefits of restoring connectivity across entire watersheds. Barrier assessment tools have improved planning, design, and the scale of effectiveness of restoration. However, as we prioritize restoration of larger watershed areas IT becomes increasingly important to improve our understanding of the relative influence of barriers by incorporating better biological ranking metrics. Static measures can miss the influence of temporal variation in hydrology that may provide temporary connectivity across some barriers. Genetic indicators can capture longer-term isolation across barriers and help to decrease uncertainty in prioritizing barriers for removal. In addition to vetting a new approach in barrier assessments, this work enhances ongoing work that is currently addressing multiple recommended recovery actions for the federally threatened louisiana pearlshell mussel (LPM margaritifera hembeli). The current recovery project for this species is jointly funded by FAC and ES and assessing the impact of barriers on host fish species and river network connectivity by monitoring fish movement across previously identified barriers in the LPM management area. By integrating with that work, we can validate the use of recent advances in conservation genomic tools as a measure of stream network connectivity. The work will inform future management and restoration efforts for LPM, evaluate the efficacy of genetic tools to assess restoration success, as well as aid in the improvement of a strategic barrier prioritization framework. Additionally, as substantial uncertainty remains around potential host species of LPM, we propose to utilize genetic metabarcoding to determine the identity of glochidia encysted on wild caught fish. Recognition of host species will support and focus future recovery efforts and allow for a more holistic approach to LPM restoration and recovery efforts.