DNA-based identification reveals illegal trade of threatened shark species in a global elasmobranch conservation hotspot

Leonardo Manir Feitosa,Wagner Macedo,Ana Paula Barbosa Martins,João Bráullio Sales,Horácio Schneider,Luís Fernando Rodrigues-Filho,Jorge Luiz Silva Nunes,Lígia Tchaicka,Rosália Souza,Iracilda Sampaio,Iann Leonardo Monteiro,Tommaso Giarrizzo,Luís Fernando Carvalho-Costa,Fernanda Gomes,Romário Gemaque

doi:10.1038/s41598-018-21683-5

Abstract

Here, we report trading of endangered shark species in a world hotspot for elasmobranch conservation in Brazil. Data on shark fisheries are scarce in Brazil, although the northern and northeastern regions have the highest indices of shark bycatch. Harvest is made primarily with processed carcasses lacking head and fins, which hampers reliable species identification and law enforcement on illegal catches. We used partial sequences of two mitochondrial genes (COI and/or NADH2) to identify 17 shark species from 427 samples being harvested and marketed on the northern coast of Brazil. Nine species (53%) are listed under some extinction threat category according to Brazilian law and international authorities (IUCN – International Union for Conservation of Nature; CITES – Convention on International Trade of Endangered Species of Wild Fauna and Flora). The number increases to 13 (76%) if we also consider the Near Threatened category. Hammerhead sharks are under threat worldwide, and composed 18.7% of samples, with Sphyrna mokarran being the fourth most common species among samples. As illegal trade of threatened shark species is a worldwide conservation problem, molecular identification of processed meat or specimens lacking diagnostic body parts is a highly effective tool for species identification and law enforcement.

Highlights

We report trading of endangered shark species in a world hotspot for elasmobranch conservation in Brazil
None of the species was recorded at all localities, and only one (R. lalandii) was landed in a unique site (Raposa)
DNA-based identification revealed seventeen species, nine (53%) of which are listed in some category of threat (IUCN, CITES or Ordinance 445)

Summary

Introduction

We report trading of endangered shark species in a world hotspot for elasmobranch conservation in Brazil. The impact of artisanal fisheries tends to be overlooked in fishery statistics due to the difficulty in obtaining reliable catch data, combined with the belief that these operations have a low impact on fishery stocks[13,14]. The inclusion of these data source would increase the official catches by up to 50%13, especially in developing countries such as Brazil[11], where artisanal fishing fleets are large, the regulation agencies are inefficient and poorly equipped for law enforcement activities, and fisheries data are inadequate or imprecise[4]. Most of the catch produced by artisanal fisheries is consumed locally[15], the more valuable species and byproducts are typically marketed in major cities or even exported

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Conclusion