Mussel Sampling and Habitat

Development of a flexible mid-sized river mussel sampling protocol and investigation of statewide multi-scale mussel habitat relationships

Principle Investigator: Dr. Jacob Westhoff

Students and Staff: PhD student Ava Laszlo



Freshwater mussels are one of the most imperiled faunal groups in Missouri and in North America. The latest estimate indicates that 70% of the North American fauna has been accorded some level of conservation status (Stein et al. 2000). In Missouri, nearly 50% of the mussel fauna is considered a species of conservation concern (SOCC; S1-S3), ranking them second only to crayfish (by percentage) as the most threatened fauna in the state. Most of the mussel SOCC, 14 species, are S1 or Critically Imperiled. Fifteen species are recognized under The Wildlife Code as State Endangered, and eleven are listed as Federally Threatened or Endangered (MDC 2022).  Approximately 65 species of freshwater mussels occur in Missouri, with species richness and diversity higher in Ozark rivers.

The Missouri Mussel Conservation and Management Plan (MDC 2008) guides MDC’s mussel conservation efforts and identifies high priority objectives to “Establish standardized quantitative and qualitative mussel sampling protocols to facilitate resource management evaluations, status assessments, presence/absence determinations, and relocations” and “Determine suitable physical and chemical habitat requirements for all life stages to identify factors limiting populations”. This proposed project will address both of those information needs and will advance our knowledge to the point where we can develop regional or statewide predictive models of mussel distribution and create a long-term standardized sampling program capable of tracking the status of mussel communities at priority locations.

The first objective will involve conducting mussel surveys at multiple sites throughout the Current River in an occupancy modeling framework whereby we use spatially replicated surveys to estimate occupancy and detection probability for mussel species.  For the second objective, we plan to oversample select river reaches around the state of Missouri using multiple mussel sampling methods to determine which methods are most efficient and what level of effort is required to meet sampling goals.  For the third objective, we will use data collected from Objective 2 and combine it with detailed habitat mapping from a companion project to assess habitat associations.  The forth objective will take advantage of an existing dataset of fish data to compare to the mussel data for any insights into fish-host relationships.


Steve McMurray (MO Dept. Conservation Project Lead), Victoria Grant (US National Park Service), Andy Roberts (U.S. Fish and Wildlife Service Missouri Ecological Services Field Office), MO Department of Conservation Staff (Travis Moore, Annie Hentschke, Kelly Rezac, Blake Stephens, Paul Cielewicz, Brian McKeage, Jason Persinger, Dyan Pursell, Sherry Gao), Brandon Sansom (USGS Columbia Environmental Research Center)


National Park Service and Missouri Department of Conservation


Winter 2023 - Winter 2027 (4+ years)