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

Abstract

Groupers (Pisces: Serranidae) of littoral environments of warm-temperate and tropical regions have expenenced intense fishery exploitation. Indicators of intense fishing include declines or change in abundance, size, spawning aggregations, and species composition. Surveys of grouper were carned out from 1995 to 1997 in the Flonda Keys, central Bahamas, southeastern Cuba, and the southeastern Dorninican Republic to iüuminate Patterns in species composition, abundance, and size, along a gradient of relative fishing pressure. 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 manne sanctuary, and were categonzed as: (1) intensively fished with little or no management for groupers (southeastern Cuba, southeastern Dorninican Republic), (2) intensively fished with numerous gear and effort regulations (Florida Keys), (3) lightiy fished with some gear and effort regulations (northern and southern Exuma Cays, Bahamas), and (4) a no-take marine fishery reserve closed to fishing (Exuma Cays Land and Sea Park, Bahamas). On each site 10 to 20 stnp transects (20 m X 5 m) were surveyed in water of 1 to 20 m depth over rocky hard-bottom habitats for density and size of grouper. Nine grouper species (2 Cephalophoiis spp., 4 Epinephelus spp., and 3 Mycteroperca spp.) were documented among aii areas. Results show that areas where grouper fishing was relatively light had greater numbers of species, density, and biomass, particularly for larger species such as Nassau grouper E. striatus. Classification of groupers by 3 life history categories or growth strategies (small, intermediate, and large) indicated significant differences in density and biomass among study areas. The density and biomass of larger grouper species were significantiy greater in the no-take m a~e reserve and iightly fished areas than in the more intensively fished areas. In 3 of the areas charactenzed as intensively fished, one of which has several grouper fishery regulations, grouper density and biomass were dominated by smail, 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 viable means to protect grouper resources, sirnphfying enforcement relative to complex catch and effort regulation, but also potentiaiiy aileviating the need to gather fishenes-dependent data.

Assessment of the effectiveness of two marine reserves in the Canary Islands (eastern Atlantic)

“…In the case of D. cervinus cervinus, for which a minimum catch size has not been established, we used the same size as that for D. sargus cadenati. Despite the simplicity of this approximation, its effectiveness has been shown in other similar studies (Kelly et al 2000, Chiappone et al 2000, Guidetti et al 2005.…”

“…En el caso de D. cervinus cervinus, para el que dicha talla mínima no está regulada, establecimos la misma que para D. sargus cadenati. A pesar de la simplicidad de esta aproximación, su eficacia se ha mostrado en otros estudios de índole similar (Kelly et al 2000, Chiappone et al 2000, Guidetti et al 2005.…”

“…Las ventajas potenciales proporcionadas por un área libre de explotación extractiva han sido consideradas en numerosas ocasiones (e.g., García-Rubies y Zabala 1990; Roberts y Polunin 1991Dugan y Davis 1993;Agardy 1994;Harmelin-Vivien et al 1995;Russ y Alcalá 1996;Chiappone et al 2000;Galzin et al 2004;Guidetti et al 2005;Micheli et al 2005). Si bien son numerosos los estudios teóricos y los basados en técnicas de meta-análisis que sugieren el beneficio potencial de las AMPs para conservar y reestablecer los stocks pesqueros, son todavía escasos los trabajos que demuestren de forma empírica la efectividad de estas AMPs, especialmente en aguas templadas (Kelly et al 2000, Willis et al 2003.…”

“…Más concretamente, estudiamos cómo la abundancia y biomasa (MRs) in order to promote the sustainable management of coastal fishery resources and preserve the marine biodiversity (Gell and Roberts 2003, Micheli et al 2005, Sale et al 2005. The potential advantages of an area free from fishing activities have been widely discussed (e.g., García-Rubies and Zabala 1990; Roberts andPolunin 1991, 1993;Dugan and Davis 1993;Agardy 1994;Harmelin-Vivien et al 1995;Russ and Alcalá 1996;Chiappone et al 2000;Galzin et al 2004;Guidetti et al 2005;Micheli et al 2005). Nevertheless, despite the numerous meta-analysis and theoretical studies showing the potential benefits of MPAs for re-establishing and conserving fish stocks, data that empirically demonstrate their effectiveness, especially in temperate waters, are scarce (Kelly et al 2000, Willis et al 2003.…”

Ocean surgeonfish Acanthurus bahianus. II. Fishing effects on longevity, size and abundance?

“…Jamaica) where human densities are high and there are intensive and uncontrolled subsistence and commercial trap-fisheries (e.g. see Munro 1983, Roberts 1995, Chiappone et al 2000, Jackson et al 2001, Rogers & Beets 2001. However, there is considerable variation in the intensity, methods and targets of reef-fish fisheries across the large range of the ocean surgeonfish.…”