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Abstract: Understanding the spatial distribution of a species is an important precondition to successfully managing marine populations. For reef fishes, this is of particular importance due to the patchy nature of reef communities. This study estimated the spatial distribution of five reef fish species on the West Florida Shelf: gag grouper (Mycteroperca microlepis), mutton snapper (Lutjanus analis), red grouper (Epinephelus morio), red snapper (Lutjanus campechanus), and vermilion snapper (Rhomboplites aurorubens). Estimation was done by combining large-scale fishery-dependent catch per unit of fishing effort with small scale fishery-independent video survey observation. Catch per unit of fishing effort was obtained from vessel logbook data while video observations of reef fish presence–absence and relative abundance were made by stratified random sampling on known reef and hard-bottom habitat in the Gulf of Mexico. Relative abundance estimates showed different abundance patterns for the five species depending on depth and geographical area. Variogram modeling suggested that gag grouper, mutton snapper, and red grouper were spatially autocorrelated on reef or hard-bottom habitats at short ranges of between 0.87 and 0.95km, while red and vermilion snapper were found to be randomly distributed. Range estimates for gag grouper, mutton snapper and red grouper were supported by variograms of depth soundings in the Gulf which produced range estimates of between 1.56 and 6.34km. Combining the relative estimates of abundance from catch per unit of effort with the spatial autocorrelation parameters from video surveys allowed us to provide stochastic fish abundance estimates at scales of about 2km2. [Copyright &y& Elsevier]

The article examines the survival of red grouper and red snapper caught on circle and J-hooks by recreational fisheries in Florida. It mentions the difference of delayed hook mortality of both species from blood loss of J-hook nicked internal organs. It notes that the survival rates of the fish correlate with feeding behavior, jaw morphology, and prey residence time. It also emphasizes the higher tag recapture rates for tagged red grouper caught on circle hooks than on J-hooks.

The article discusses a study which analyzed the spatial-seasonal variation in catchability of the red grouper Epinephelus morio fishery in the Campeche Bank, northern coast of the Yucatan Peninsula using data from 1973 to 1977. It reveals that the adult catchability was higher during the reproductive period in the eastern part of the region. The researchers recommend that coastal areas near Celestún, Dzilam de Bravo, Rio Lagartos, and El Cuyo, be considered as fishing restricted areas to limit fishing mortality and promote stock recovery.

Epinephelus morio (Red Grouper) is an important component of commercial fisheries for the United States and Mexico. Fishery-independent long-line surveys that utilized standardized sampling designs were conducted along the west Florida shelf, Florida and Campeche Bank, Mexico (2001-2002). Detecting true differences in abundance and sizes are difficult, but by using standard collection and aging methodologies, the level of bias was kept at a minimum. Relative abundance was higher in the Campeche Bank compared to the west Florida shelf (1.74 and 0.63 Red Grouper/100 hook hr, respectively). Fish from the Campeche Bank were also significantly smaller at length and weight. Differences in length, weight, and relative abundance of Red Grouper may be because of historical fishing pressure and management regulations, or the available carrying capacity of each area for Red Grouper. These differences have a substantial impact on how an overfished population can recover and be sustained. [ABSTRACT FROM AUTHOR]

Abstract: Red grouper (Epinephelus morio) were collected from the west coast of Florida, the central area of fishery harvest in U.S. waters, by fishery-dependent sources during 2000–2005. The west Florida shelf was divided into two regions: north (capture locations ≥28°N latitude) and south (capture locations <28°N latitude). Significant differences were found for age, length, and size-at-age by region and by gear; red grouper from the north were significantly younger and smaller on average than those from the south. Regional differences were also noted with respect to age progression; year class trends were only detected in the north. The 1996 year class dominated the landings in 2000–2001 (ages 4 and 5) and the 1999 year class dominated in 2004–2005 (ages 5 and 6). Regional data were fit to a size-modified von Bertalanffy growth model indicating smaller asymptotic length (L ∞) and faster growth rate (k) in the north (north: L ∞ =800mm, k =0.23mmyear−1, t 0 =1.12; south: L ∞ =863mm, k =0.15mmyear−1, t 0 =0.05). Mortality estimates derived from catch curves resulted in higher total and fishing mortality in the north for both gears. Alternative explanations of regional differences likely depend on nursery delineation and correlation to periodic environmental events such as red tides and hurricanes; all possibly important factors based upon anecdotal information. Nevertheless, our finding of regional demographic differences in red grouper from the west coast of Florida suggests a more complex population spatial structure for red grouper. [Copyright &y& Elsevier]

Statistical analysis of the red grouper (Epinephelus morio) fishery in the Yucatan continental shelf indicates that this species follows a constant pattern of spatial distribution through time. Using time series of relative abundance from 1984 to 2001 (commercial CPUE) by month and fishing area, red grouper distribution was addressed by means of serial correlation and ANOVA parametric tests. These methods showed that during each year, red grouper spatial distribution is significantly different in January and February. This period is characterized by the highest abundance, particularly in the fishing areas located at the eastern part of the continental shelf. The implementation of time or area closures to rebuild the stock should involve these findings in the analysis in order to determine the impact on the fishery. [Copyright &y& Elsevier]