Occurrence and capture of elasmobranchs by artisanal fisheries off the State of Ceara, Brazil, with emphasis on landings at the Mucuripe Inlet in Fortaleza

Abstract

Elasmobranchs (sharks and rays) play crucial roles in marine ecosystems by acting as regulators of the trophic chain. However, their populations are in decline due to several factors, including intrinsic biological traits such as late reproduction and low fecundity, compounded by overfishing and habitat degradation. Brazil is responsible for the capture and trade of several elasmobranch species, making it one of the leading consumers of elasmobranchs globally. Additionally, issues with the accurate identification of captured species contribute to illegal, unreported, and unregulated (IUU) fishing of endangered species. This problem is exacerbated when most captures are conducted by small-scale fleets, as the artisanal nature of these activities hinders access to reliable fishery data. Ceará is one of the states where artisanal fishing predominates and has a history of elasmobranch captures. However, the scattered nature of the available information complicates an overall assessment of the fishing status of this group in the state. For this reason, the present study undertook: (a) an initial chapter evaluating the feasibility of alternative methodologies for identifying elasmobranch species captured in Ceará, using an alternative data collection method based on video analysis from a social network (YouTube); (b) a review of the history of elasmobranch catches and landings in Ceará and at the Mucuripe Embayment in Fortaleza—one of the state's main landing sites for sharks and rays — through literature review and field sampling; and (c) a species identification study of a lamniform specimen landed by artisanal fishing at Mucuripe through DNA sequencing. The specimen was identified as Isurus oxyrinchus, and the importance of correct species identification was discussed, along with historical records of another lamniform shark species occurring in the region, the white shark (Carcharodon carcharias). Co-management and the use of alternative data sources can help develop a more sustainable fisheries sector, and conservation actions along the coast of Ceará are urgently needed.