O uso da paisagem Amazônica pela pesca comercial

Abstract

The commercial fishing is an activity of great importance at the Amazon basin. It is subject to seasonal climatic, cultural and economic influences, which could be different by region into this huge basin. In recent years several studies have been carried out applying geoprocessing techniques to better evaluate the fisheries. These studies consider the effect of landscape variables on several spatial scales on fisheries, but for the better management of fishing activity in the Amazon region it is necessary to evaluate these effects in local units. The commercial fisheries of Benjamin Constant and Iranduba were studied, aiming to evaluate the regional differences of the fisheries and their spatial dynamics in the Amazonas. The data were collected in 2012 at the main landing sites of both municipalities. The common name of the fish landed, catch per species (kg), fishing effort, fishing grounds, fishing gear and vessels used were registered. The largest variety of fish caught was recorded in Benjamin Constant, but Iranduba obtained the highest total landing. The pacús (Mylossoma spp.; Metynnis spp.; Myleus spp.) and acarí-bodó (Pterygoplichthys pardalis) were the most landed at Benjamin Constant. The aracú (Schizodon fasciatus) and curimatã (Prochilodus nigricans) were the most important species in the landings of Iranduba. In general, the production was higher during the falling-water period. The rivers, lakes and coast were the most exploited environments and the gillnet was most used equipment. Twenty-six fishing sites were identified in Benjamin Constant and thirty-two sites in Iranduba. In Benjamin Constant the fishermen explored fishing sites within a radius of up to 280 km from the municipal seat, and in Iranduba were explored distant sites up to 70 km from the municipality. The largest catches were recorded on the Solimões river in the high and low waters in Benjamin Constant. While in Iranduba, the highest catch in the period of high water was observed in the lake of the Janauacá, and in low waters in the beach of the Manaquiri. The Catch per Unit Effort (CPUE) varied from 10.2 to 288.6 kg/man.day. The highest yields were observed in locations far from the municipal seat in the low water period and in locations close to the municipal seat during the high water period. The motorized canoe was the most used vessel in the fisheries of both municipalities. Variations were observed in the fisheries and in the spatial dynamics of the activity in each region. These variations need to be taken into account when developing fisheries management strategies, to avoid the development of generalist policies that are ineffective to reach the sustainability of fish stocks.