Incorporating Ecology into Survey Design: Monitoring the Recruitment of Age-0 Gags in the Eastern Gulf of Mexico

We developed a multiple-gear survey (183-m haul seine and 6.1-m otter trawl) that was designed to supplement long-term, fishery-independent survey data on age-0 Gags Mycteroperca microlepis in Apalachicola Bay, Tampa Bay, and Charlotte Harbor, Florida. The supplemental survey design specifically considered juvenile Gag recruitment ecology and thus targeted the deep, polyhaline seagrass habitats that are utilized by age-0 Gags yet infrequently sampled. It also expanded the spatial coverage of ongoing surveys to include two unsampled estuaries (St. Andrew Bay and Big Bend [Apalachee Bay]) where Gag recruitment had been documented. Analyses of data collected in long-term and supplemental surveys (2008-2012) demonstrated the effectiveness of this sampling approach. The size ranges of Gags collected in long-term and supplemental surveys were similar, but age-0 individuals were captured more frequently and CPUE was significantly higher in the supplemental surveys. Interannual patterns of variability in Gag recruitment were similar between gear types and among sampling designs, although the coefficient of variation was lowest for the combined data from long-term and supplemental seine surveys. Data from these complementary surveys will improve our ability to characterize age-0 Gag recruitment. Nevertheless, additional information on habitat availability-combined with a better understanding of the estuarine systems' relative contributions to nearshore Gag populations-will be required to maximize the utility of these data in predicting fisheries productivity.