Abstract

Traditionally, the capture of fish in Cuba has exhibited seasonal patterns in landing volumes, mainly associated with the reproductive season of the most important resources, among them several species of snapper (Lutjanidae) and grouper (Serranidae). This seasonality is determined by several factors, but particularly by the concentration of fishing effort, and the vulnerability of the species during the reproduction period, and is particularly marked in species that aggregate predictably at specific times and places to spawn. Analysis of a long series of time data on landings since the 1960s on six fish species of key commercial importance in Cuba revealed that fishing activity and responses to fishing appear to be quite specific according to the biological characteristics of each species. These species range from those that gather at very few and quite specific locations for very brief periods each year, such as the Nassau grouper, Epinephelus striatus, through species that exhibit varying degrees of concentration in time and space in aggregation formation, such as the lane snapper, Lutjanus synagris, mutton snapper, Lutjanus analis, cubera and gray snappers, Lutjanus cyanopterus and L. griseus, to those with a very low degree of concentration and predictability while spawning, as in the yellowtail snapper, Ocyurus chrysurus. Monthly catch data from the whole Cuban platform from 1962 to 2005 for the five snapper species and the Nassau grouper were obtained from several sources of statistical information at the Ministry of the Fishing Industry. Total annual catches and monthly average catches were estimated for each species. In addition, experienced fishers and fish biologists were interviewed to obtain additional information and anecdotes, and published literature was reviewed. The results indicated that responses to targeted fishing during the spawning season, usually on aggregations or during migrations to aggregations sites, varied between the different species studied. Those species that were more concentred in timing and more predictable in their location of spawning showed the most marked declines in landings, the most extreme being the Nassau grouper which collapsed in the 1980s. The mutton snapper, on the other hand, which exhibits less concentrated aggregations than the lane snapper and has many more known aggregation sites, although considerably reduced over the last few decades, did not show as much decline as the lane snapper. The yellowtail snapper does not aggregate markedly and showed the least indication of decline of all the species studied. Independently of the above factors in relation to overfishing of these species, there is also evidence that certain environmental factors may contribute to declines in snapper populations in Cuba, particularly the reduction of seagrass areas, refuge and feeding areas for these species in some regions, such as the inner waters of the Archipelago Sabana-Camagüey and the northern part of the Gulf of Batabanó. Coral bleaching and disease, possibly the result of the increase in water temperature during ENSO events, and other kinds of habitat degradation, could also be involved

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