Freshwater Turtles as a Renewable Resource: Using the Red-Eared Slider (Trachemys scripta elegans) as a Model Species
Freshwater turtles have a long history of being utilized by humans. For centuries, turtles have been used as a protein resource and in traditional medicine, playing an important role in cultures across the globe. Wild turtle harvests have historically and currently been unsustainable. While some regulatory regimes have been implemented in different regions, many taxa remain unprotected and there is a need for improving the current regimes. The objectives of this dissertation is to assess the problem of freshwater turtle harvest and trade in the United States of America (US), focusing first on the entire southeast region and then specifically on the Texas harvest paradigm. This dissertation also examines turtle farming as an alternative to wild population harvest. The first study reported the evidence of large, unsustainable exports of freshwater turtles out of the US, despite recently implemented restrictions on turtle harvest in several states of the Southeast US. Moreover, I provided evidence for negative consequences of non-uniform harvest regulations across the Southeast US. For example, harvest can continue illegally in the states that provide protection, with these turtles being exported from the states that provide no legal protection. This study suggests necessity of establishing guidelines mandating the labeling of sources for all exported turtles. Better control and law enforcement during shipping operations can be attained by requiring legal certification and documentation of turtles exported from unregulated states by the shipping agent. In my second study, I examined patterns of overland movements across the landscape by adult red-eared sliders (Trachemys scripta elegans). I also developed a novel method of monitoring the movement at a higher resolution than previously reported. This study is directly related to establishing buffer zones as well as establishing potential harvest seasons. It also allowed me to test the source-sink harvest paradigm applied to Texas freshwater turtle populations. The study provided the evidence of different seasonal patterns between male and female red-eared sliders. It also provided evidence for flaws in the current management regime in Texas, but also gave a direction for future studies that might improve this management. Finally, I tested alternative options for harvesting adults from wild populations, such as freshwater turtle farming. Specifically, I developed a biological and economic model for farming red-eared sliders in Louisiana. This model demonstrated the economic challenges of farming red-eared sliders for meat markets. However, it gives a perspective on what the future market may develop. Future studies should focus on modifying this model to fit more desirable and rare taxa.
Mali, I. (2014). <i>Freshwater turtles as a renewable resource: Using the red-eared slider (Trachemys scripta elegans) as a model species</i> (Unpublished dissertation). Texas State University, San Marcos, Texas.