DNA Zip‐coding: identifying the source populations supplying the international trade of a critically endangered coastal shark

Abstract

There is an urgent need for population-specific trade information for overexploited sharks, as international trade regulations are becoming an important tool for their conservation [i.e., listings on the Convention on International Trade in Endangered Species (CITES)]. We tested a genetic stock identification (GSI) workflow to quantify the relative contributions of different source populations of the CITES-listed scalloped hammerhead shark Sphyrna lewini to international trade hubs for products such as dried fins. We grouped published mitochondrial control region sequences from wild-captured sharks sampled in 15 locations into 9 differentiated populations that provide broad coverage of the species global distribution. GSI simulations established that these populations are highly identifiable and we trialed this approach to assess the provenance of processed fin trimmings collected randomly from the retail market of Hong Kong, one of the world's largest shark fin trade hubs in 2014-2015 (N = 72). In this pilot survey, we found over 75% of scalloped hammerhead fin trimmings came from two Pacific Ocean populations, but mostly from the Eastern Pacific (61.4%, of all trimmings; SE 7.1%) where this species is listed as 'Endangered' under the United States Endangered Species Act. Six of the nine populations were found in this sample of the market, indicating near global sourcing of scalloped hammerhead fins in Hong Kong. We suggest technical and sampling considerations for employing GSI at fin trade hubs in the future to investigate regional sourcing of scalloped hammerheads and other coastal sharks in international trade. Random GSI in trade hubs could revolutionize our understanding of global shark trade dynamics and provide critical information required to effectively implement shark fisheries management and trade restrictions.

Genetic connectivity of the scalloped hammerhead shark Sphyrna lewini across Indonesia and the Western Indian Ocean

“…Shark fin product, including from scalloped hammerhead are very popular in Hong Kong [20], where trade regulations for endangered species and effective regulations are promoted [16,20,21]. The population structure of S. lewini, which is important for fisheries stock management, has been widely investigated in different coastal areas and ocean basins on a global and regional scale [17-19, 22, 23].…”

“…Shark fin product, including from scalloped hammerhead are very popular in Hong Kong [ 20 ], where trade regulations for endangered species and effective regulations are promoted [ 16 , 20 , 21 ]. The population structure of S .…”

Phylogenomics and species delimitation for effective conservation of manta and devil rays

“…For example, diagnostic markers with the power to discriminate between populations could be employed for determining the geographic origin of devil ray samples. Such traceability tools could be used to understand the impact of fisheries on individual populations or to identify geographic regions that may be routinely supplying the gill plate trade (Fields et al., 2020; O'Malley et al., 2017). The extent of population structuring described within M. alfredi , M. kuhlii and M. mobular indicates that future traceability studies will be feasible in these species.…”

Mitochondrial DNA Profiling to Combat the Illegal Trade in Tortoiseshell Products

“…The illegal trade in endangered wildlife is having devastating impacts on many of the world's species and is broadly considered a global threat to biodiversity (Veríssimo and Wan, 2019). Among the best known cases are elephant ivory (Gao and Clark, 2014), rhino horn (Milliken and Shaw, 2012), tiger skin and bones (Nowell and Ling, 2007), shark fins (Fields et al, 2020), and bear gall bladder (Jabin et al, 2019) to name a few. Rapid globalization, increased connectivity, complex trade networks, and a continued cultural and social demand for wildlife products will continue to drive populations toward extinction (Miller et al, 2019;Hitchens and Blakeslee, 2020).…”

“…Molecular techniques have been successfully applied to illegal poaching of elephants, tigers, rhinoceros, birds, sharks, etc. (Nishant et al, 2018;Fields et al, 2020). For example, DNA extracted from ivory has been used to identify the location of the poaching hotspots for African elephants by matching the genetic signature of confiscated ivory to geographic or population specific genetic signatures (Wasser et al, 2015).…”