Habitat use of juvenile goliath grouper Epinephelus itajara in the Florida Keys, USA

Abstract

This study reports the distribution, abundance and habitat use of juvenile goliath grouper Epinephelus itajara along fringing red mangrove Rhizophora mangle shorelines of the Florida Keys, USA. The species has been protected from fishing in US waters since 1992, after reaching commercial extinction, yet juvenile habitat use remains poorly studied. The aim of this study was to evaluate the importance of underwater mangrove habitat structure and complexity in determining distribution of juvenile goliath grouper in the Florida Keys. Visual underwater surveys were used to record juvenile presence, abundance and size. Habitat characteristics as continuous variables (depth, canopy, overhang and prop root width) and nominal variables (bottom type, sun exposure, shoreline shape and shoreline type) were also recorded. Juveniles aggregated in sites with high structural complexity, soft sediment and eroded shorelines. Well-developed fringing red mangrove shorelines were the preferred juvenile goliath grouper habitat.