Small scale fisheries operative units in the west central region of the Gulf of California, Mexico

The multispecific and multigear character of small scale fisheries is complex and often difficult to understand, especially when basic data necessary for evaluation are scarce. In this study the distribution of spatial and temporal fishing pressure of operative fishery units OU was analysed. Each unit was integrated per vessel which, through similar forms of operation, takes advantage of the same species in the central region of the Gulf of California. The identification of the OU is based on a survey about the forms of operation and they were complemented with the catch data per species collected by the National Commission of Aquaculture and Fishing from 1998 to 2010. A hierarchical cluster analysis was applied and nine OUs were determined, which included: jig-caught jumbo squid; amberjacks with surface fishing nets; octopus with diving gear; groupers with hooks; shark with surface fishing nets; stingrays with bottom-set net; triggerfishes, mojarras, ocean whitefish and hogfish with hooks; weakfish, snappers, parrotfishes and grunts with bottom-set nets; Pacific sierra with surface fishing nets. The interaction processes between OUs are described through thematic maps in relation to the use of fishing areas and pressure by overlapping activities. It is proposed that when the fishermen have more than one fishing permit, they should choose what OU to work. Furthermore, if the permit is for finfish fishing they need to decide in what operative unit it is best to participate, accounting for factors such as abundance, price and distance to the fishing location. All of the OUs are relevant for the economy of the fishermen of the region and their interaction is necessary for maintaining fishery production.