Abstract

Other than recreational and commercial catch data, there is little information on groupers from the Gulf of Mexico (GoM) off Louisiana. The economic value and lack of information about members the family Epinephelidae make them a priority for stock assessments. The purpose of this research is to gain much needed information about these data-poor spe-cies, which includes data on age and growth and nutritional condition. Grouper species are being sampled from six natural banks and at several oil and gas platforms in the northern GoM. Growth increments, or annuli, are being counted on sec-tioned sagittal otoliths to determine length at age for several species. This will be used to derive von Bertalanffy growth curves that will provide information concerning L? and W?. Nutritional condition will be derived from a BIA (Biological Impedance Analysis) device. The BIA has been field tested by taking measurements on red snapper, which we catch more consistently in the GoM, and tissue samples taken from the same fish were processed in the laboratory using a bomb calo-rimeter. A predictive model of nutritional condition was constructed from impedance values and the caloric density estimated in the laboratory using bomb calorimetry. The BIA may be a useful tool in quickly understanding the nutritional condi-tion of the groupers we collect. One advantage of using BIA is that it is non-destructive, making it possible to release the fish alive if necessary. Nutritional information combined with growth rate will yield important information on GoM group-ers off the coast of Louisiana

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