Site fidelity, residence time and movements of red snapper Lutjanus campechanus estimated with long-term acoustic monitoring

Abstract

Residence time, site fidelity and movements for red snapper Lutjanus campechanus (Lutjanidae) were estimated from long-term telemetry monitoring (December 2005 to June 2010) at 6 sites (1 natural and 5 artificial reefs) in the northeastern Gulf of Mexico. Each site consisted of an array of 5 receivers, with 1 at the center reef site and 4 receivers placed 1100 m north, south, east and west of center (2 km radius detection area). Throughout the study, a stationary control transmitter was located 400 m south of the center receiver at each site to estimate changes in detection rates from environmental factors. These receiver arrays enabled fishery independent estimations of fishing mortality, natural mortality and emigration. Event analysis was used to estimate site fidelity and residence, based on right-censoring fishing and natural mortality. Median residence time was 542 d, ranging from 1 to 1099 d, with 72% of fish staying at least 1 yr at the site. Some fish (n = 12) showed seasonal and directed movements to other sites (up to 8 km away) and returned to original sites up to 7 mo later. Diel movements away from the structure tended to occur at night. Site fidelity and residence times of red snapper in the present study were greater than in any previous study and show the importance of artificial reefs for this species.