Assessing the changes in international trade of marine fishes under CITES regulations – A case study of seahorses

Trade regulations may be useful for conserving marine species that are suffering from overexploitation. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) has emerged as an instrument to help tighten fisheries management. However, the impacts of CITES regulations have not been examined for the trade in fully marine fishes. This study used seahorses ( Hippocampus spp.), the first fully marine fishes listed in CITES Appendix II since treaty inception, as a case study. Drawing on Customs data from Taiwan and Hong Kong SAR (which cover pre-CITES periods), iterative-segmented regressions were applied to investigate changes in seahorse trade corresponding to CITES interventions. Principal component analyses were conducted to understand characteristics of seahorse source countries, and a gravity model of trade was applied to identify predictors of seahorse trade volumes. This study found that the total weight of seahorses in documented trade decreased significantly after CITES implementation, recorded trade became concentrated in fewer countries, and prices increased. Seahorse source countries were found having more fishers, demersal fish catch and general trade with China, compared to other range states. However, countries that reported no exports, unchanged export volumes or declining volumes after CITES were similar. In addition, volumes traded between two countries were found significantly higher when the two countries were closer together or when the source country had a lower per capita GDP or higher demersal catch. This study can help guide targeted actions to maximize CITES effectiveness for marine species.