Date of Award

Spring 5-11-2024

Document Type

Thesis

Degree Name

Master of Science in Fisheries and Wildlife Science

Department

Biological Sciences

College

College of Science, Technology, Engineering, & Mathematics

Committee Chair

Thomas Nupp

Second Committee Member

Kyler Hecke

Third Committee Member

Kendall Moles

Program Director

Thomas Nupp

Dean of Graduate College

Sarah Gordon

Abstract

Freshwater mussels are one of the most imperiled taxonomic groups in the world, consequently, much effort is being expended to document the distribution of many mussel species. One tool that can aid in characterizing mussel distributions are species distribution models (SDM). I conducted two studies pertaining to freshwater mussel distributions: (1) utilize Maximum Entropy (MAXENT) modeling to predict potential areas of suitable habitat for the threatened Ouachita Fanshell (Cyprogenia sp cf aberti), and (2) survey small tributaries of the Ouachita River watershed to fill a portion of the information gap surrounding mussel communities in under-surveyed streams. Through changing spatial scale and incorporating biological information (fish host habitat suitability), I was able to assess the impacts of methodological processes on habitat suitability predictions for Ouachita Fanshell. My results revealed that altering spatial scales (whole watershed versus sub-watersheds) and incorporating fish host information changed the amount and location of predicted suitable habitat for Ouachita Fanshell. Steam segments that were categorized as suitable habitat were defined by measures of hydrology, such as low frequency of winter floods, and were characteristic of larger drainage areas (km2). These results indicated that Ouachita Fanshell could potentially inhabit larger tributaries within the watershed. During mussel surveys, I documented mussels in seven of ten streams, some of which were intermittent or heavily degraded. Louisiana Fatmucket (Lampsilis hydiana) was the most abundant species and showed significant differences in length frequency distributions among two spatially disjunct streams. These differences in length distributions were likely a result of hydrological differences. The results of this study provide insights into the distribution of mussels within the Ouachita River watershed and highlight the importance of methodological considerations in predicting habitat suitability. This information can be used to expand current survey efforts to describe and document mussel communities.

Available for download on Thursday, October 10, 2024

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