Freshwater Mussel Inventory at Ozark National Scenic Riverways

Westhoff JT , Laszlo AM , Huggins BJ . Freshwater Mussel Inventory at Ozark National Scenic Riverways. 2023-2026. National Park Service

Freshwater mussels are among the most imperiled faunal groups in Missouri and North America, yet their distribution and population status within Ozark National Scenic Riverways (OZAR) remain poorly characterized. Although earlier surveys documented portions of mussel communities in the Current River and Jacks Fork, much of the park has never been systematically sampled. These gaps limit the ability of park resource managers to make informed decisions regarding rare species protection, river access planning, habitat conservation, and mitigation of emerging threats. This project provides OZAR with the first park‑wide, repeatable inventory of freshwater mussels based on a statistically robust survey design. The objectives were to (1) update occurrence information for all unionid mussels within OZAR, including Species of Conservation Concern and federally listed species; (2) estimate occupancy, detection probability, catch per unit effort, and species richness; and (3) evaluate historical fish distribution records to better understand linkages between mussels and their host fishes. By addressing major uncertainties in mussel distribution and community composition, the project delivers foundational data critical to science‑based management. Results directly support park needs by identifying mussel aggregation areas, informing evaluation of proposed river use actions, guiding placement of river access sites, and supporting endangered species management and future restoration efforts. The resulting dataset also establishes a baseline for long‑term monitoring and contributes to broader conservation planning by state and federal partners. Overall, this project enhances OZAR’s capacity to protect sensitive aquatic resources and maintain the ecological integrity of its river systems.

Type
Project
Authors
Westhoff, Jacob; Laszlo, Ava; Huggins, Billy
Publisher
National Park Service
Units
OZAR
Keywords
aquatic habitat, aquatic resources, biodiversity, conservation planning, detection probability, ecological integrity, endangered species, freshwater mussels, habitat assessment, host fishes, hydrologic processes, IMD, mussel inventory, National Park Service, NPS, NPS Inventory and Assessment Program, NPS Inventory and Monitoring Division, occupancy modeling, park management, rare species management, recreational use, resource protection, restoration planning, river access planning, sediment stability, species of conservation concern, species richness, unionids, water management

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