April 28 – Seminar: Biotic and Abiotic Influences on Common and Imperiled Freshwater Mussels at Multiple Spatial and Temporal Scales with Inferences to Global Change

Presenter: Tamara Jane Pandolfo, Doctoral Dissertation Defense Seminar, Ph.D. in Zoology
Title: Biotic and Abiotic Influences on Common and Imperiled Freshwater Mussels at Multiple Spatial and Temporal Scales with Inferences to Global Change
Date/Time: Monday, April 28, at 1:00 PM
Location:  2213 Gardner Hall
Abstract:
Freshwater mussels are among the most imperiled faunal groups globally, and relevant ecological information is urgently needed to guide their management and conservation. We explored the influence of abiotic and biotic factors on the detection and occupancy of freshwater mussels in the Tar River basin, North Carolina. Detection probability for all species was 0.42 (95% CI, 0.36 –0.47) with no species- or site-specific detection effects identified. Mean occupancy probability among species ranged from 0.04 (95% CI, 0.01 – 0.16) for Alasmidonta undulata, an undescribed Lampsilis sp., and Strophitus undulatus to 0.67 (95% CI, 0.42 – 0.86) for Elliptio icterina. Catchment-scale variables and mussel species traits influenced the occupancy of mussels. We also integrated existing survey records from 1986 to 2011 in a dynamic occupancy model. Results indicated that occupancy probability for 14 species decreased over the study period. Mean survival for all species was high (0.97, 95% CI = 0.95 – 0.99). However, the mean colonization probability was very low (< 0.01, 95% CI = < 0.01 – 0.01). Further, we combined extensive field measurements of temperature and biotic integrity with mussel and fish thermal tolerance limits to generate a comprehensive assessment of potential threats mussels face as temperatures continue to rise with global change. Average summer temperatures at mussel-occupied sites in the upper Tar River basin ranged 16.2 – 34.7 °C. Temperature threshold exceedance durations indicated that both acute and chronic freshwater mussel thermal tolerance thresholds were met or exceeded. These findings will enhance the understanding of freshwater mussel ecology and guide conservation strategies in the face of global change.