DNA Barcode Reveals the Bycatch of Endangered Batoids Species in the Southwest Atlantic: Implications for Sustainable Fisheries Management and Conservation Efforts.

Claudio Oliveira,Juliana Beltramin De Biasi,Bruno Lopes Da Silva Ferrette,Fausto Foresti,Fernando Fernandes Mendonça,Ingrid Vasconcellos Bunholi,Marina Provetti Miranda,Matheus Marcos Rotundo,Rodrigo Rodrigues Domingues

doi:10.3390/genes10040304

Abstract

Today, elasmobranchs are one the most threatened vertebrate groups worldwide. In fact, at least 90% of elasmobranch species are listed in the International Union for Conservation of Nature (IUCN) Red List, while more than 40% are data-deficient. Although these vertebrates are mainly affected by unsustainable fishery activities, bycatch is also one of the major threats to sharks and batoids worldwide, and represents a challenge for both sustainable fishery management and for biodiversity and conservational efforts. Thus, in this study, DNA barcode methodology was used to identify the bycatch composition of batoid species from small-scale industrial fisheries in the southwest Atlantic and artisanal fisheries from southeast Brazil. A total of 228 individuals belonging to four Chondrichthyes orders, seven families, and at least 17 distinct batoid species were sequenced; among these individuals, 131 belonged to species protected in Brazil, 101 to globally threatened species, and some to species with trade restrictions provided by Appendix II of the Convention on International Trade in Endangered Species (CITES). These results highlight the impacts on marine biodiversity of bycatch by small-scale industrial and unmanaged artisanal fisheries from the southwest Atlantic, and support the implementation of DNA-based methodologies for species-specific identification in data-poor fisheries as a powerful tool for improving the quality of fisheries’ catch statistics and for keeping precise bycatch records.

Highlights

Batoidea is a superorder of cartilaginous fish commonly known as rays, stingrays, or skates
A total of 652 base pairs of c oxidase subunit ®I Tissue gene (COI) barcode from 228 individuals were successfully sequenced and identified to the species level, and the results showed a high similarity (98.0–100.0%)
44.3% belonged to species listed on the threat categories of the International Union for Conservation of Nature (IUCN) Red List, while 57.47% were protected in Brazil under Ordinance No 445, dated 17 December 2014, issued by the Department of the Environment (MMA)

Summary

Introduction

Batoidea is a superorder of cartilaginous fish commonly known as rays, stingrays, or skates (hereafter “batoids”). They are currently the largest subgroup of the Chondrichthyes class and include. Batoids are caught as bycatch in different fishing equipment worldwide [3]. As a consequence of the high exposure to fishing activity on the continental shelf, some batoid species are on the brink of extinction. Five of the seven most endangered Chondrichthyes families worldwide are from the Batoidea superorder [4]. In 2018, the International Union for Conservation of Nature (IUCN) assessed a total of 573 batoids, of which ~21% are in the threatened categories, and 41.7% are data deficient [5]

Methods

Results

Conclusion