Intensive Commercialization of Endangered Sharks and Rays (Elasmobranchii) Along the Coastal Amazon as Revealed by DNA Barcode

Abstract

Elasmobranchs represent a well-defined group, composed of about 1,150 species inhabiting diverse aquatic environments. Currently, several of these species have been classified as threaten due to overexploitation. Therefore, we used DNA barcode to identify traded species of sharks and stingrays in the municipality of Bragança (Amazon coastal region), a major fishery landing site in northern Brazil. We collected a total of 127 samples labeled into 24 commercial nomenclatures over 1-year period. Twenty species were discriminated and 13 of them are recognized under some threatening status. In relation to sharks, Carcharhinidae showed the highest number of species, half of them classified as endangered, followed by hammerhead sharks (Sphyrnidae), with four species also regarded as threatened with extinction. The Rhinopteridae and Dasyatidae rays were the most abundant groups, with trade records of the following threatened species: Rhinoptera brasiliensis, Rhinoptera bonasus, Hypanus berthalutzae, and Fontitrygon geijskesi. It is noteworthy that threatened species of elasmobranchs have been frequently and regularly exploited because of inefficient fishery management policies. Therefore, effective inspection practices need to be incorporated in fisheries, including the use of DNA barcode to enable a reliable method of species authentication and to assure the proper commercialization.

The first report of DNA barcoding of commercially important fish in Nias Islands, Indonesia

“…This shark is the most frequently exploited among the Sphyrnidae family and ranks fourth most commonly found and sampled species (Feitosa et al 2018). Genus Sphyrna identified in the present study are threatened with extinction (Martins et al 2021). According to fishermen's information, the waters of Faekhuna'a served as a habitat for hammerhead sharks and was a primary catch zone.…”

Shark bycatch of the acoupa weakfish, Cynoscion acoupa (Lacèpede, 1801), fisheries of the Amazon Shelf

“…In an analysis of sharks sold in the fish market in Braganca, an important fishing port in Parástate, Martins et al (2021) identified 11 taxa of the orders Orectolobiformes and Carcharhiniformes, of which, eight are classified as endangered. Clearly, then, the generic classification of catches by their vernacular names does not reflect the true diversity of the impacted fauna, and limit the more effective analysis of the dynamics of existing stocks and their response to fishing pressure, whether targeted specifically or indirectly, as bycatch (Davidson et al, 2016).…”

Quality analysis of genomic DNA and authentication of fisheries products based on distinct methods of DNA extraction

“…The use of molecular genetics as a tool in forensics and for the certification of commercial products has proven to be highly efficient in solving fraud cases or substituting seafood products [ 7 , 53 ]. For instance, several reports based on genetic data of commercialized fish products have identified endangered species [ 7 , 54 ], providing helpful information about the illegal trade of species threatened with extinction [ 55 ].…”