Mapping goliath grouper aggregations in the southwestern Atlantic

Abstract

(Lichtenstein, 1822), is the largest reef fish in the western Atlantic Ocean, reaching up to 2.5 meters long and > 400 kg (BULLOCK et al., 1992). The species matures at 5-8 years with a maximum age of 37 years (BULLOCK et al., 1992). Some characteristics of goliath grouper that make them particularly vulnerable to overfishing include their large body size, slow growth, high longevity, late maturity, and the formation of predictable seasonal spawning aggregations (SADOVY; EKLUND, 1999). Consequently, the species has suffered sharp population declines across its entire distribution range (CRAIG et al., 2009; McCLENACHAN, 2009; GIGLIO et al., 2015) and currently is classified as Critically Endangered by the International Union for the Conservation of Nature (CRAIG, 2011). In Brazil, the species have been fully protected by a federal law since 2002, however, illegal fisheries threaten the population’s recovery (GIGLIO et al., 2014a).During the reproductive season, goliath grouper form relatively small (10 to 100 individuals) spawning aggregations (SADOVY; EKLUND, 1999) with individuals migrating distances up to 300 km to specific spawning areas (PINA-AMARGOS; GONZALEZ-SANSON, 2009). Data on the spatial and temporal distributions of spawning aggregations are mostly available for the northern hemisphere (SADOVY; EKLUND, 1999; MANN et al., 2009; KOENIG et al., 2011; 2016). In Brazil, anecdotal reports of aggregation sites have been described using fishers’ knowledge (GERHARDINGER et al., 2009; FERREIRA et al., 2014) and