An Assessment of the Diverse Freshwater Turtle Fauna of Mississippi

Nestled within the Southeastern United States Turtle Priority Area, Mississippi boasts impressive freshwater turtle diversity and is home to 8.6% of extant turtle species. Despite this impressive richness, few studies have assessed freshwater turtle assemblages in this hotspot of aquatic diversity. This research aimed to elucidate the distributions and abundances of freshwater turtle species through a statewide investigation of all major river drainages of the state. Using baited hoop nets (90 cm and 120 cm diameter), turtles were collected, identified to species and sex, and measured, before being released. Turtle assemblages were assessed in both lotic and lentic environments from the Pascagoula, Pearl, Tombigbee, and Mississippi River drainages and were shown to vary among habitat types and between drainages. In addition to the statewide assessment of distributions and abundances, the Indicators of Hydrologic Alteration software was employed to detect drainage-wide hydrological alterations in the free-flowing Pascagoula River, the moderately altered Pearl River, and the heavily channelized and impounded Tombigbee River. The severely modified Tombigbee drainage showed significantly distinct hydrological alteration scores to the relatively pristine Pascagoula drainage after the construction of the Tennessee-Tombigbee Waterway, which connected two historically disjunct drainages through a series of 10 locks and dams in the Tombigbee River. The loss of intra-annual variation in streamflow and homogenization of this environment has allowed for lentic species, notably Trachemys scripta elegans, to attain extremely high abundances in the Tombigbee when compared to the Pascagoula