Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico

Site Fidelity, Movement, and Growth of Red Snapper: Implications for Artificial Reef Management

Andrew J. Strelcheck, James H. Cowan, Jr., and William F. Patterson, III

doi: https://doi.org/10.47886/9781888569971.ch10

Abstract.—Red snapper, Lutjanus campechanus, (n = 4,317) were captured and tagged at 14 experimental artificial reefs of two designs during quarterly research cruises (n = 17) off coastal Alabama between January 1999 and October 2002. Six-hundred and twenty nine recaptures were reported, representing 578 tagged red snapper. Sixty-five percent of recaptures (n = 412) were made at the site of release on subsequent research cruises, while 217 recaptures were reported by fishers. Eighty-six percent of individuals with known recapture locations moved 2 km or less from the site of release; mean and maximum distances moved were 2.1 km and 201 km, respectively. Nine red snapper moved greater than 80 km. Mean dispersion rate from release sites was 8.6 m d^⁻1. Annual site fidelity of tagged fish was estimated using nonlinear decay models. Estimated annual site fidelity ranged from 48% to 52% year^⁻1 and was not significantly affected by artificial reef design, reef fish biomass at the site of release, or artificial reef densities surrounding each tagging site. Growth rates were estimated by regressing the change in red snapper total length versus the days a fish was at liberty. Mean growth rate for all recaptured fish was 0.206 mm d^⁻1. Growth rates were significantly affected by reef size (faster at larger experimental reefs) and reef fish biomass (slower at tagging sites supporting low reef fish biomass), but were not affected by artificial reef density. Moderate site fidelity and low dispersion rates during our study provide support for the hypothesis that artificial reefs off Alabama are suitable habitat for adult red snapper. However, characteristics of artificial reefs, such as reef size and standing stock biomass, may affect red snapper growth. Furthermore, ratios of instantaneous growth in weight to total mortality (G/Z) suggest artificial reefs off Alabama serve as net sinks (i.e., G/Z < 1) of red snapper biomass under current fishing mortality rates.