Groupers (Pisces : Serranidae) in fished and protected areas of the Florida Keys, Bahamas and northern Caribbean

Groupers (Pisces: Serranidae) of littoral environments of warm-temperate an d tropical regions have experienced intense fishery exploitation. Indicator s of intense fishing include declines or change in abundance, size, spawnin g aggregations, and species composition. Surveys of grouper were carried ou t from 1995 to 1997 in the Florida Keys, central Bahamas, southeastern Cuba , and the southeastern Dominican Republic to illuminate patterns in species composition, abundance, and size, along a gradient of relative fishing pre ssure. We assumed that the diversity, composition, density, and size would serve as indicators of fishing pressure in these areas. The study locations included 2 national parks and a national marine sanctuary, and were catego rized as: (1) intensively fished with little or no management for groupers (southeastern Cuba, southeastern Dominican Republic), (2) intensively fishe d with numerous gear and effort regulations (Florida Keys), (3) lightly fis hed with some gear and effort regulations (northern and southern Exuma Gays , Bahamas), and (4) a no-take marine fishery reserve closed to fishing (Exu ma Gays Land and Sea Park, Bahamas). On each site 10 to 20 strip transects (20 m x 5 m) were surveyed in water of 1 to 20 m depth over rocky hard-bott om habitats for density and size of grouper. Nine grouper species (2 Cephal opholis spp., 4 Epinephelus spp., and 3 Mycteroperca spp.) were documented among all areas. Results show that areas where grouper fishing was relative ly light had greater numbers of species, density, and biomass, particularly for larger species such as Nassau grouper E. striatus. Classification of g roupers by 3 life history categories or growth strategies (small, intermedi ate, and large) indicated significant differences in density and biomass am ong study areas. The density and biomass of larger grouper species were sig nificantly greater in the no-take marine reserve and lightly fished areas t han in the more intensively fished areas. In 3 of the areas characterized a s intensively fished, one of which has several grouper fishery regulations, grouper density and biomass were dominated by small, non-targeted species such as the graysby C. cruentatus and the coney C. fulva. This pattern may indicate a second-order effect of fishing, indicative of potential changes in competition or predation. No-take marine fishery reserves represent a vi able means to protect grouper resources, simplifying enforcement relative t o complex catch and effort regulation, but also potentially alleviating the need to gather fisheries-dependent data.