Priority areas for the conservation of the fish fauna of the Amazon Estuary in Brazil: A multicriteria approach

The definition of priority areas for the conservation of fish faunas is still relatively incipient in comparison with efforts for the protection of terrestrial systems, despite the fact that fishes are the group of organisms most affected by anthropogenic impacts. Given the lack of adequate management in the most important sectors of the Amazon Estuary, the objectives of the present study were to identify priority areas for conservation, based on the analysis of ecological and economic criteria, and indices referencing the fish fauna, integrated in a GIS environment. This was the first application of a methodological approach of this kind to the Amazon Estuary. Fish specimens were collected in the main channel and tidal creeks of the southern Amazon Estuary – Guajará and Marajó Bays and the mouth of the Guamá River and associated islands – between 2004 and 2011, during both the dry (July to December) and rainy seasons (January to June), using gillnets and trawls. A total of 14 ecological and fishery criteria were grouped in five indices – environmental quality and diversity, habitat use, fishery index, and relative abundance (CPUE). Maps were produced, based on different scenarios for the conservation of the fish fauna of the study area. Medium to high conservation priorities were defined by all the indices throughout the study area. The scenarios indicated that the northern portion of Marajó Bay and all sectors during the dry season present medium to very high priorities for conservation.