Mussel Inventory at Ozark National Scenic Riverways 2023-2024 - Open Format Dataset

National Park Service Inventory and Monitoring Division. 2026. Mussel Inventory at Ozark National Scenic Riverways 2023-2024 - Open Format Dataset. National Park Service. Fort Collins CO https://doi.org/10.57830/2318480

The Ozark National Scenic Riverways (OZAR) is a national park unit located in the Ozarks region of Missouri and encompasses much of the mainstem Jacks Fork and Current River. Past surveys of freshwater mussel populations indicated potential declines for many species in OZAR. We conducted occupancy-based surveys at 60 randomly selected sites during 2023–2024 to update species inventories and establish a repeatable baseline. We also examined fish and mussel records to determine if the absence of host fish should be further investigated as a potential cause of mussel decline. Visual searches detected 13 mussel species, with catch-per-unit-effort (CPUE) and species richness lower than previous surveys, suggesting continued decline. Mean species-level occupancy across the mussel community (i.e., all species detected) was low (<25%), and detection probability for observing a freshwater mussel during a 45-minute person-survey averaged 29%. Mussel occurrence decreased in spring-influenced reaches and riffle habitats but increased in off-channel and glide/race habitats. A host fish linkage index indicated that most mussel species have viable hosts present, though species dependent on few or lentic-associated hosts may face reproductive limitations. These results provide managers with actionable data for conservation planning and outline potential future survey methods, including targeted habitat sampling to sustain mussel diversity in OZAR.

Type
Data Package
Authors
National Park Service Inventory and Monitoring Division
Date of Issue
2026-05-28
Publisher
National Park Service
DOI
10.57830/2318480
Units
OZAR
Keywords
Bivalves, Freshwater mussels, IMD, Mussels, National Park Service, NPS, NPS Inventory and Monitoring Division, NPS Species Inventory Program, Open-format, OZAR, Ozark National Scenic Riverways
License
Public Domain

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