Cosecha comercial del alga roja Gelidium robustum en Baja California Sur, Mexico

In Mexico Gelidium robustum is the only species that is commercially exploited to produce agar, generating a high annual income from agar exports. In spite of its economic importance there are few studies regarding the biomass of the beds that are being exploited. This work analyzes the fishery of G. robustum in Baja California Sur, Mexico from 1980 to 1994. It takes into consideration the volume of harvest, the fishing effort, and the catch per unit effort (CPUE), and the latter (CPUE) is analyzed to see if it may be used as an index of relative abundance of the resource. The total production was 7872 dry tons with variations throughout the years. The fishery was in a phase of intensive exploitation (1980-1987). During this period, fishing effort was large and the CPUE was low. Afterwards the fishing effort was reduced and the abundance of the resource recovered. There were seasonal variations of the relative abundance with greater abundance in summer and autumn than in winter. Of the different zones of exploitation, the largest harvest volumes and CPUE were from punta Eugenia to bahia Tortugas contributing in 63% of the total production, therefore this zone sustains in good measure the fishery of G. robustum in Baja California Sur. Taking account of the fishery's characteristics, the use of CPUE as an indicator of the relative abundance of Gelidium could be a good alternative to evaluate changes in beds under exploitation.