Overfishing of Threatened Bycatch Species in a Marine Protected Area: The Elasmobranchs of Banc d'Arguin, Mauritania

Elasmobranch (rays and sharks) populations are vulnerable to overexploitation due to their slow growth, late maturity, and low fecundity. Industrial fishery impacts on sharks and rays are known, whereas impacts of artisanal fisheries are less understood. We quantified catches of sharks and rays in artisanal fisheries at the Parc National du Banc d'Arguin (Banc d'Arguin), Mauritania (West Africa) during 1998–2020, a period when fishing effort increased around 2006, catches increased, but catch-per-unit-effort declined substantially. Shark nets and meagre fixed gill nets were used to catch elasmobranchs, with catches comprising over 60% of elasmobranch species. Therefore, elasmobranchs were not bycatch, but rather, the target of fisheries. Of 33 elasmobranch species captured, 94% of shark species and 76% of ray species are threatened with extinction. We recommend that management approaches should focus on fishing locations with the highest occurrence of threatened elasmobranch species in catches, through new regulations on fishing gear types and discouragement of trade in elasmobranch products from Banc d'Arguin.