Conservation and ecology of the yellow-blotched sawback (Graptemys flavimaculata)

William Winsyl Selman II

Abstract

The role of species conservation is becoming increasingly important due to the mounting pressures from humans on habitats and populations of organisms. This is particularly evident in riverine ecosystems throughout the world where the human demand for freshwater resources is increasing, and consequently, the number of imperiled aquatic organisms is also growing. The seven chapters of this dissertation primarily focus on the Yellow-blotched Sawback, Graptemys flavimaculata, an endangered riverine turtle that is endemic to the Pascagoula River system of southeast Mississippi, USA. At the population level, we aimed to study the impacts of Hurricane Katrina on two study populations within the Pascagoula River system, while also determining likely causes of population decline related to the storm. On a larger scale, we sought to determine the current distribution and abundance of G. flavimaculata, as well as another similar species (Pascagoula Map turtle, Graptemys gibbonsi ), throughout the Pascagoula River system. At the individual/population level, we wanted to better understand the basking ecology of the species by analyzing basking behavior throughout the active season. In addition, the role of human recreation on the species was studied by measuring behavioral (basking) and physiological (stress hormone levels and shell