Abstract

Red snapper from the northem Gulf of Mexico off Louisiana were found to differ significantly in age and fork length distribution between fishery dependent and fishery independent sources. Commercially harvested red snapper ranged from 320 to 880 mm fork length and from 2 to 48 yr; those from among the mortalities subsequent to the explosive removal of an obsolete oil and gas platform varied from 220 to 730 mm and from 1 to 9 yr. The truncated age distribution of the fishery independent sample supports the hypothesis that red snapper recruit to structures such as oil platforms at age 2 yr and then emigrate to other habitats after several years of residency. Fork length was also found to be a competent predictor of age for red snapper < 500 mm. Due to the virtual absence of age 2 red snapper both in the commercial and recreational harvests and in fishery independent trawl collections, sampling of red snapper populations at explosive removal sites is the lone method of tracking cohort strength at age two.

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