Conservation and sustainable use of turtle populations worldwide: Past, present, and future strategies

Background/Question/Methods

Turtles have been utilized by people for centuries (e.g., as a food source, in traditional medicine, and in the pet trade). Due to overexploitation without regard for sustainability, many living chelonians of the world are in perilous decline. Overexploitation of green turtles as food resources in the Greater Caribbean resulted in drastic population declines. In the United States, Diamondback terrapin populations declined after intense harvest and today, incidental crab pot mortalities are a continuing impact. Worldwide the current status of poorly known softshell turtle species need investigation due to their popularity in the bushmeat trade. The most striking examples come from Asia, where increasing demand for turtles in food markets has led to the collapse of a continental turtle fauna. With unregulated harvest in this region, nearly 50 species are now at risk of extinction each having seen range-wide population collapses. By contrast, legal, regulated harvest of green sea turtle eggs in Costa Rica provides an example of sustainable use within a successful, community-based conservation program.

Results/Conclusions

We review how anthropogenic uses and approaches have influenced the future sustainability of turtle populations across the world. We compare two major sustainability approaches and conclude that "bottom-up" approach and community-based conservation has been more successful strategy toward sustainable use of chelonians. We examine how freshwater turtle populations respond to drastically increased turtle harvest using an example from the southern USA. In this study, we find overall desrease in turtle abundance when compared to the 30 year old data. We also detect differences in sizes of adult turtles in protected vs. unprotected sites. We discuss the life history characteristics that influence the sustainability of turtles as a renewable natural resource. We use modern examples to depict the capacity for turtle populations to compensate for the increase of additive mortality from direct harvest alongside indirect anthropogenic impacts. By understanding the response of turtle populations to overexploitation, compensatory or additive mortality models can be applied globally to better inform management strategies and better understand the framework necessary for achieving sustainable use of turtles as a natural resource.