Estimating the Tag-Reporting Rate and Length-Based Selectivity of Red Drum (Sciaenops ocellatus) in South Carolina Using a Long-Term Tag-Recapture Study
|Tag-recapture studies are often utilized to generate precise, externally derived, estimates of stock assessment parameters such as tag-reporting rate and selectivity. These estimates can be used to increase the accuracy of recent stock assessments for red drum (<i>Sciaenops ocellatus</i>), which have exhibited significant uncertainty and largely leave the population status in question. Using more than forty years of red drum tag-recapture data available from the South Carolina Department of Natural Resources (SCDNR) including a high-reward tagging study, we estimated the tag-reporting rate of red drum, as well as the length-based selectivity of fishery-independent sampling gears (trammel net, electrofishing, stop net, and longline) and recreational hook-and-line. Tag-reporting rate in South Carolina is high overall, approaching maximal reporting (100%) in St. Helena Sound, Charleston Harbor, and Winyah Bay, while Port Royal Sound displayed 58.9% reporting rate. The shape of fishery-independent selectivity curves depended on gear type, with each gear selecting for a different size class. A dome-shaped pattern of recreational hook-and-line selectivity was observed for harvested and released fish in nearly all management periods, though the size of maximum selectivity in South Carolina recreational fisheries varied based on fate of the fish after capture. The results of this study provide essential information to be used in future red drum stock assessments and will subsequently influence management of the species.
|Estimating the Tag-Reporting Rate and Length-Based Selectivity of Red Drum (Sciaenops ocellatus) in South Carolina Using a Long-Term Tag-Recapture Study