Fishers' resource mapping and goliath grouper Epinephelus itajara (Serranidae) conservation in Brazil

Abstract

Goliath grouper (Epinephelus itajara) aggregations and relative abundances were described and mapped through the use of fishermen's local ecological knowledge in Babitonga Bay in southern Brazil. Six well-experienced informants were asked to individually provide information about goliath grouper abundance and distribution, drawn over a satellite image of the study area, which was later overlaid and gathered into a final map. According to our informants, the goliath grouper occurs along a broad salinity and depth range, from shallow estuarine areas (less than 5 m deep) with high freshwater input (smaller individuals, up to 150 kg) to coastal marine-dominated environments (at least 35 m deep); (larger individuals more common, frequently reaching more than 300 kg). Fishermen referred to goliath groupers inhabiting hard substrates such as rocky reefs around islands and continental shores, submerged rocky outcrops and shipwrecks (juveniles and adults). At least two aggregation sites mapped (ranging from 2 to 60 individuals) could be concluded as spawning aggregation sites through evidence of high abundance and spawning activity. Priority research and conservation targets were identified and discussed for Babitonga Bay (e.g., design of a tagging experimental program and establishment of a marine protected area). Fishers' resource mapping provided a means of exchanging information among various disciplines while maintaining methodological rigor in a clear and straightforward way of presenting fishers' knowledge. The use of fishers' sketch maps is a promising tool for marine conservation in Brazil, with special regard to adaptive co-management regimes, where frequent environmental re-evaluations are needed.A abundância relativa e agregações de meros Epinephelus itajara foram descritas e mapeadas através do conhecimento ecológico local de pescadores da baía Babitonga, sul do Brasil. Seis informantes muito experientes desenharam individualmente sobre uma imagem de satélite da área de estudo informações sobre abundância e distribuição de meros, seguindo-se de uma sobreposição das imagens em um mapa final. O mero ocorre ao longo de uma larga faixa de salinidade e profundidade (principalmente juvenis), de áreas estuarinas rasas (menos que 5 m de profundidade) com alta incidência de água doce, até ambientes costeiros marinhos (ao menos até 35 m de profundidade); (indivíduos maiores são mais comuns, alcançando mais de 300 kg). A espécie é também encontrada habitando substratos consolidados como recifes rochosos ao redor de ilhas e continente, parcéis submersos e emersos e naufrágios. Ao menos duas das agregações mapeadas (variando de dois a 60 indivíduos observados) puderam ser consideradas agregações reprodutivas através de evidências de alta abundância e atividade reprodutiva. Ações de pesquisa e conservação foram identificadas e discutidas para a baía Babitonga. O mapeamento de recursos possibilitou uma forma de trocar informações entre várias disciplinas, mantendo rigor metodológico e apresentando o conhecimento dos pescad...

Fishermen's local ecological knowledge on Southeastern Brazilian coastal fishes: contributions to research, conservation, and management

“…However, the coastal fish in this region have been exploited by several fishing communities, an uncontrolled and unrecorded recreational fishery, plus a large scale commercial fishery. Fisheries management measures in Brazil have been reactive and even delayed regarding the vulnerability of large reef fishes to overexploitation: fishing of E. itajara was only forbidden when populations of this fish declined to critical levels (Gerhardinger et al, 2009). Our data and those from other survey indicate that other reef fishes, such as E. marginatus, may be also in need of urgent management measures.…”

“…We analyzed fishermen's LEK to improve fish and fisheries related research and management, according to the data less approach to fisheries management (Johannes, 1998). Since the classical study by Morril (1967), several other studies have recorded that small-scale fishermen have a detailed LEK about fish (Johannes, 1981;Johannes et al, 2000;Poizat & Baran, 1997;Aswani & Hamilton, 2004;Silvano & Begossi, 2005;Gerhardinger et al, 2009). Notwithstanding the methodological improvements on data collection, two recent issues on LEK research deserve consideration: reliability and accuracy (Maurstad et al, 2007).…”

“…These spawning aggregations have been observed in the Caribbean (Coleman et al, 1996;Sadovy, 1996), Pacific (Johannes, 1981) and Mediterranean (Louisy, 1996), but such behavior has not yet been recorded for E. marginatus in Brazil (Bertoncini et al, 2003). Spawning aggregations have been recorded in the southern Brazilian coast for a closely related species, the mero (Epinephelus itajara), based on fishermen's LEK (Gerhardinger et al, 2009). Although Búzios Island fishermen's LEK indicates that schooling and migration of E. marginatus may be related to spawning aggregations, fishermen did not mention such behavior.…”

“…Such situation is typical of coastal fisheries in tropical developing countries (Ruddle & Hickey, 2008). The data-less approach to fisheries management (Johannes, 1998) may be thus appropriate to the Brazilian coast too, where fishermen usually have a detailed knowledge about fish (Marques, 1991;Silvano & Begossi, 2005;Gerhardinger et al, 2009).…”

“…Previous studies have analyzed relevant topics related to fishers' LEK in the Brazilian coast, such as fish reproduction , migration (Silvano & Begossi, 2005), and ecology of endangered reef fish (Gerhardinger et al, 2009). Some of these surveys addressed both fishers' LEK and biological studies of coastal fishes Silvano & Begossi, 2010).…”