Release Mortality of Undersized Fish from the Snapper–Grouper Complex off the North Carolina Coast

Abstract

Red porgy Pagrus pagrus, scamps Mycteroperca phenax, and gags M. microlepis support valuable recreational and commercial fisheries in North Carolina. Fish in the snapper–grouper complex are managed to prevent overfishing and maintain a stable spawning stock. We investigated postrelease mortality of 263 undersized red porgy, scamps, and gags that were captured by angling and subjected to short-term (2 h) and long-term (48 h) holding experiments. Fish were caught at depths ranging from 15 to 45 m using traditional bottom-fishing hook-and-line gear. Catch per unit effort ranged from 0.11 to 1.80 fish/rod-hour (FRH) for sublegal-sized fish and from 0.06 to 0.50 FRH for legal-sized fish. Nontarget species predominated in the catch (N = 1,135), but the red porgy was the most frequently caught individual species (N = 196). The effects of short-term (2-h) holding within species were similar between fish held in different locations (oxygenated live well or cage anchored to the seafloor); mortality did not differ between the two holding location groups. Mortality of fish subjected to short-term holding in the live well was 6.1%; mortality of fish in the submerged cage was 10.5% for the 2-h holding period and 12.3% for the 48-h holding period. There was no significant effect of anatomical hook location on mortality of gags or scamps. However, hook location significantly affected survival of red porgy; individuals hooked in the lip were 11.34 times more likely to survive than fish hooked in other locations. The results of this study suggest that short-term holding is appropriate for assessing mortality of undersized fish caught offshore in a hook-and-line fishery.