SEAFWA 2018

AUTHORS: Luke Pearson, Gabrielle Berry, Carl Qualls – Department of Biological Sciences, University of Southern Mississippi

ABSTRACT: The alligator snapping turtle (Macrochelys temminckii) is currently under review by the US Fish and Wildlife Service and other regulatory and management agencies to determine if populations have declined sufficiently to warrant federal listing as a threatened species. Despite having a presumed near statewide distribution, there is a paucity of records for M. temminckii in Mississippi, thus leaving a void of knowledge at the core of this species’ geographic range. Therefore, our goal was to assess the status of M. temminckii throughout the state, beginning in south Mississippi. We systematically trapped 17 locations within the Pascagoula River drainage in 2017, capturing 126 M. temminckii (17 males; 34 females; 75 juveniles) in 878 trap nights, averaging 0.16 turtles per trap night (0 – 0.33 TTN). In river sites, no large males (> 50 cm CL) were captured, and the catch rate of juveniles was higher than in the lakes. Because of this size discrepancy, M. temminckii captured in lakes were larger ( > 4 cm CL and > 4 kg heavier) than those in rivers. The differences in adult capture rates may be caused by inherent habitat and microhabitat differences between the two systems, or increased fishing pressures in rivers. However, the abundance of juveniles at both site types, spanning a range of size classes, is a good sign of recruitment in these populations. Currently, systematic trapping is being conducted in the Pearl River drainage to assess population sizes and distributions in a significantly more altered system.