Shark breeding grounds and seasons in the Gulf of California: Fishery management and conservation strategy

Abstract

Sharks show high biological fragility and, given the intense fishing regimes to which they are exposed in the Gulf of California, it is necessary to establish a conservation and management strategy providing for the protection of their nursery areas. We reviewed the literature concerning shark reproductive biology to determine priority management areas in the Gulf of California by complementarity analysis and different selection criteria. Four levels of management and conservation priority were determined for six quadrants: level 1 corresponded to the area off Mazatlán (Sinaloa) and the area of El Sargento, La Ventana, and Punta Arenas (Baja California Sur); level 2 to the areas of Teacapán (Sinaloa) and Seri (Sonora); level 3 to the areas of San Francisquito-El Barril (Baja California) and Kino Bay (Sonora); and level 4 to the area of La Manga (Sonora). Analysis of space-time variables in a geographic information system indicated that 71% of the commercially important shark species concentrate in coastal zones, mainly in bays, coastal lagoons, estuaries, and wetlands (central and southern Gulf of California) during spring and summer (May–August), except for Prionace glauca, Isurus oxyrinchus, Alopias pelagicus, and Squatina californica that reproduce in winter and spring. The protection of recruitment areas (critical habitats) during peak breeding periods should be an essential part of any resource management plan.