Artes de pesca artesanal nos reservatórios de barra bonita e bariri: Monitoramento pesqueiro na bacia do médio rio tietê

Abstract

The fishing gears used in Barra Bonita and Bariri reservoirs, Middle Tietê River, were evaluated in order to provide objective information to assess the need for a revision of the legal framework governing this activity. Monitoring of the fishery production was carried out in the main fishing nuclei, collecting data about the catch composition (number and biomass), selectivity of fishing gear and the by-catch. Information about the predominant fishing arts, catch per effort unit and seasonality of fish production, as well as environmental information, were also obtained. Monthly field campaigns for sampling were done, when the researchers followed the fishing activity, making a detailed record of the catches and the employed fishing gears. It was found that gill net is the least selective among the four modalities practiced, but it is the only one which has legal support. Higher selective fishing gears, such as trawls, cast nets and fishing beat, act mainly on tilapia, a non-native species whose exploitation could be considered beneficial to the conservation of the native fish populations through the reduction of the interspecific competition for resources. Thus it is suggested the restriction of the use of less selective fishing equipment and the liberation of fishing gear that targets the non-native species of cichlids, aiming to reduce the fishing pressure on indigenous species.