Impactos ambientais das hidrelétricas de Santo Antônio e Jirau sobre a estrutura da pesca artesanal no Rio Madeira

Abstract

The Amazon Basin harbors the greatest freshwater biodiversity on the planet, with the Madeira River sub-basin standing out due to its vast hydrological expansion and over 1,300 recorded fish species. As the population grows, renewable energy sources such as hydroelectric power have expanded, particularly in the Amazon region. Fishing in the Madeira River is a crucial activity for the subsistence and economy of local communities. However, the construction of the Santo Antônio and Jirau hydroelectric plants has led to significant environmental impacts, affecting the diversity and abundance of native fish species. This study aimed to analyze the effects of these hydroelectric plants on the ichthyofauna of the Madeira River Basin, based on fish landing data collected at the ports of Humaitá (downstream) and Guajará-Mirim (upstream) between 2000 and 2019. The data were organized according to three predominant taxonomic orders in the regional fishery, Siluriformes, Characiformes, and Cichliformes, and analyzed across pre- and post-dam construction periods. Results showed a greater biomass reduction in Guajará-Mirim (56,62%) compared to Humaitá (48,9%). Among the taxonomic orders, Characiformes were the most affected, with declines exceeding 72% upstream and 56% downstream. The findings are expected to support socio-environmental management strategies that address the ecological and economic impacts on artisanal fishing, recognizing it as a vital source of food and income for Amazonian communities.