The shark meat market threatens elasmobranchs in Brazil

Biodiversity on sale: The shark meat market threatens elasmobranchs in Brazil

Marcelo Merten Cruz, Bruna Elenara Szynwelski, Thales R. Ochotorena de Freitas

ABSTRACT:

1. Elasmobranchs are apex predators that play a crucial role in marine ecosystems by regulating the dynamics of food webs, as well as connecting different trophic levels across habitats.
2. The large-scale removal of elasmobranchs impacts the energy transfer in trophic interactions. The pressure of unsustainable fisheries is considerable, as most elasmobranchs have reproductive strategies that render them unable to recover their demographic status after depletion.
3. In Brazil, elasmobranchs are broadly commercialized under the generalist common name of ‘cação’ (namely, shark meat). This allows threatened species to be commercialized and makes the tracking of different species difficult.
4. DNA barcoding of the Cytochrome c oxidase subunit 1 (COI) gene was applied to identify the different species sold as ‘cação’ along the coastline of Brazil. Fifty-seven samples from 33 cities in 15 coastal states of Brazil were purchased and analysed.
5. Bioinformatic analyses revealed the presence of 17 species that were sold as ‘cação’. Among them, Prionace glauca (blue shark) was the most abundant. Other species, listed as Endangered under the IUCN Red List of Threatened Species, were also uncovered as being in the shark meat trade, such as Sphyrna lewini (scalloped hammerhead), Isurus paucus (longfin mako shark), and Squatina guggenheim (angular angel shark).
6. These findings have reinforced the necessity to correctly label the commercialized species. Public actions towards species-specific management plans must be applied, as well as monitoring the supervised allied educational programmes.

Aquatic Conservation, Early View, DOI: 10.1002/aqc.3710

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