AGE, GROWTH AND AGE AT MATURITY OF GAG, MYCTEROPERCA MICROLEPIS, FROM THE SOUTHEASTERN UNITED STATES DURING l994--l995

摘要

The gag, Mycteroperca microlepis, is one of the most important snapper/grouper com- plex species hareested commercially in the southeastern United States. We investigated the age, growth, and age at maturity of gag in the South Atlantic Bight (SAB) during l994 and l995. Otoliths were collected from l964 gag, of which ages were obtained for l783 specimens with a mean length of 820 mm TL and a median age of 5 yrs old. Data collected dndng l994--95 were compared to data collected from the SAB during l976-- 82. Observed mean lengths at ages l through l0 and age-l8 were significantly larger during l994--95 than l976--82 (P < 0.05). The age at first maturity decreased by one year from 3.8 yrs old in l976--82 to 2.8 yrs old in l994--95. The maturity-at-age curves were significantly different (P < 0.0l, probit analysis). Our study shows significant changes in some life history parameters that may have resulted from increases in fishing mortality Given the limitations of other potential management strategies, a system of "marine re- serves" may be the most practical method of stabilizing the population of gag in the SAB.