Influence of Circle Hook Size on Catch Rate and Size of Red Grouper in Shallow Waters of the Southern Gulf of Mexico

Abstract

AbstractHigh rates of undersized catch and discard mortality are common in fisheries for Red Grouper Epinephelus morio in the Gulf of Mexico and Atlantic Ocean. Reducing undersized catch rate in these fisheries requires more effective regulation of the minimum size limit (MSL). One potential method is to regulate hook selectivity for target species. Three circle hook sizes (11/0, 12/0, and 13/0) were tested to assess the effect of hook size on Red Grouper catch rate and size in the shallow waters of the Yucatan Peninsula coast, which is the primary fishing zone for the region's small‐scale grouper (family Epinephelidae) fishery. Red Grouper was always the numerically dominant species in catches (76–81%) for all hook sizes. Hook size did not affect mean catch rate. Significantly longer fish were caught in the 13/0 hook size treatment than in the 11/0 and 12/0 treatments, which did not differ. Nonetheless, when considering the MSL regulation applicable in Mexico's Red Grouper fishery (36.3 cm TL), high percentages of undersized Red Grouper were still caught, regardless of hook size. The hook sizes required in the Yucatan small‐scale fishery (10/0–12/0) provide little if any improvement in Red Grouper MSL regulation. Real improvement would require the effective release of undersized fish as well as a reduction in the number of undersized specimens caught and in potential cryptic sources of fish release mortality (e.g., barometric trauma). Furthermore, the current applicable Red Grouper MSL only really attempts to control growth overfishing and ignores recruitment overfishing.Received December 22, 2014; accepted September 3, 2015