The Role of Maturity in Artificial Habitat Selection by Female Red Snapper

The Red Snapper Lutjanus campechanus is a reef-associated species found throughout the Gulf of Mexico that relies on artificial structures for habitat. In this study, we used Bayesian models to determine habitat selection by different sizes and ages of female Red Snapper and to identify whether there was a difference in habitat selection between immature and mature fish. Red Snapper (n = 693) were sampled using vertical longlines from March or April through November of 2016-2018 off the coast of Mississippi at different artificial structure types (platforms, artificial reefs, and rigs-to-reef structures [hereafter, rigs-to-reefs]) and depths (shallow, <20 m; mid-depth, 20-49 m; and deep, 50-100 m). To adjust for the traditional occurrence of mature fish being larger and older than immature fish, only fish within the intersection of the FL (n = 616) and age (n = 622) ranges of immature and mature classes were used in these analyses. Fork length and age of immature and mature fish increased with increasing depth, but immature fish had a larger increase in FL per unit depth than mature fish. Immature fish on artificial reefs were found to be older than immature fish at platforms, while there was no age difference between the two structures for mature fish. There was no difference in FL or age between rigs-to-reefs and platforms or artificial reefs for immature fish, but FL and age of mature fish were greater at rigs-to-reefs than at platforms and artificial reefs. However, maturity did not play a role in how age increased with depth or with differences in FL between artificial reefs and platforms for mature fish. These differences in habitat use based on maturity should be considered along with FL and age to inform management regulations for Red Snapper.

Automated summary

This study used Bayesian models to determine habitat selection by different sizes and ages of female Red Snapper, finding significant differences in habitat selection between immature and mature fish. These differences in habitat use based on maturity should be considered along with size and age to inform management regulations for Red Snapper.