Influência de áreas protegidas sobre o tamanho corpóreo de peixes de lagos de várzea na Amazônia

Abstract

Floodplain areas in the Amazon directly influence the life cycle of fish. Fishing in the region is essential, both nutritionally and economically, and is the main source of protein and income for riverside populations. However, overfishing has led to a decline in the body size of species, compromising the sustainability of fish stocks and local food security. In view of this, studies have shown that fishing agreements have generated economic and environmental benefits for local populations as well as for the species. This work analyzes the impact of different levels of protection and fishing regulation on fish size in floodplain lakes in the Amazon, comparing areas with full protection, fishing agreements, and non-protected areas. We used five years of seasonal sampling, including fish species of commercial and subsistence interest. Our initial hypothesis (H1) is that larger sizes occur in protected areas. The general objective was to estimate L50 and L100 and to evaluate the impact of protection and fishing agreements on the body size of six fish species. Fish samples collected in four different locations were analyzed: Ponta do Catalão, Ilha da Paciência, Piagaçu-Purus Sustainable Development Reserve and Abufari Biological Reserve. The L50 and L100 values were higher in locations with greater protection. For Mylossoma albiscopum, the L50 and L100 were higher in protected areas, and species such as Potamorhina altamazonica and Potamorhina latior showed larger average and maximum sizes in protected areas. The results for adult size from L100 indicated that, in general, fish in protected areas (RDS Piagaçu-Purus and REBio Abufari) are larger compared to non-protected areas, such as Ponta do Catalão and areas with a fishing agreement, such as Ilha da Paciência. These results confirm hypothesis H1, demonstrating that protected areas preserve larger adult fish, which suggests benefits of conservation strategies for the sustainable management of fishery resources. The study highlights the importance of protected areas in maintaining fish stocks, contributing to a better understanding of the relationship between conservation and management of fish resources.