Associate Professor University of Michigan, Michigan, United States
Global wildlife trade threatens a wide diversity of species that are common in both pet and consumption trades. The Convention on International Trade of Endangered Species (CITES) is the primary mechanism for controlling international wildlife trade and preventing overexploitation. However, measuring the efficacy of CITES is difficult, possibly leading to uninformed or even counterproductive interdiction efforts. We use 20 years of legal, commercial exports of live, freshwater turtles from the US—a group of species at high risk of overexploitation—as a case study to examine the effects of CITES listings on trade dynamics and compare spatiotemporal trends and dynamics of trade across all native genera. For each listed genus, we analyzed changes in export volumes and spatial networks in 3 ways: (1) average change and (2) change in trend in the years before and after CITES listing, and (3) immediate change following listing. We further triangulated our findings with qualitative data to better discern direct and indirect drivers of trade patterns. Our study revealed overall and individual boom-and-bust trends of exports for different taxa likely driven by several factors, including CITES listings. We also found that CITES had mixed effects on export volumes for both Appendix II and III species, including a slower rate of exports of Graptemys and Clemmys spp. post-listing and higher on-average export volumes of Malaclemys and Macrochelys spp. post-listing. The diversity of spatial trade networks, on the other hand, consistently declined for CITES and non-CITES listed genera. These results likely point to differences in demand and species’ availability from captive breeders, farms, or wild harvest which are important to consider in future listing decisions given the implementation and permitting capacity of agencies. However, a lack of reliable data on the source of turtles, as with many other species traded internationally, limits our ability to understand these drivers as well as the efficacy of CITES listings in preventing overexploitation.
