A relação entre a variação hidrológica e os recursos pesqueiros no baixo Amazonas, Santarém, Pará (The Relationship between Hydrologic Variation and Fishery Resources at the Lower Amazon, Santarém, Pará)

Na Amazonia, as grandes flutuacoes do nivel dos rios modulam a pesca e influenciam no quantitativo capturado pelos pescadores. Nesse sentido, objetivou-se caracterizar e avaliar o efeito da variacao hidrologica sobre os recursos pesqueiros no municipio de Santarem, Para. As informacoes sobre as especies do pescado desembarcado foram obtidas por entrevistas realizadas com os pescadores no periodo de 2014 a 2015. Fases hidrologicas foram caracterizadas com base nos dados da estacao hidrometeorologica de Santarem, disponibilizados pela ANA (2000 a 2015). A relacao entre as especies registradas e as variaveis ambientais (cota, precipitacao e temperatura da agua) foi verificada pela Analise de Correspondencia Canonica (CCA). Observou-se que a flutuacao sazonal do rio Tapajos e definida por quatro fases (enchente, cheia, vazante, seca), sendo que a cheia (7,77 m) e seca (2,28 m) sao periodos extremos. Os menores volumes de producao de pescado ocorreram de dezembro a fevereiro, enquanto que os meses de abril e setembro apresentaram os maiores volumes. Nos meses de marco a junho, prevalecem especies das familias Anostomidae, Prochilodontidae, Characidae e Pimelodidae, em novembro e dezembro (seca) a familia Pimelodidae. Os dois primeiros eixos da CCA explicaram 52,4% da relacao entre as especies e variaveis, indicando que o periodo hidrologico e determinante na variacao sazonal do pescado. Assim, o entendimento das variaveis hidrologicas junto aos recursos pesqueiros, sao subsidios para auxiliar a gestao e o ordenamento da atividade. A B S T R A C T In the Amazon, large fluctuations in rivers’ level modulate fishing and influence the quantity captured by fishermen. The objective of this study was to characterize and evaluate the effect of hydrological variation on fishery resources in the municipality of Santarem, Para. Information on the fish species landed was obtained by interviews with fishermen from December 2013 to January 2015. Hydrological phases were characterized based on data from the Santarem hydrometeorological station (2000 to 2015). The relationship between the recorded species and environmental variables (water height, rainfall, water temperature) was verified by Canonical Correspondence Analysis (CCA). It was observed that the seasonal fluctuation of the Tapajos River is defined by four phases (rising, flood, lowing, dry), and the flood (7.77 m) and dry (2.28 m) are extreme periods. The lower volumes of production occurred from December to February, while the months of April and September presented the highest volumes. From March to June, species of the families Anostomidae, Prochilodontidae, Characidae and Pimelodidae prevail, in November and December (dry), only the family Pimelodidae. The first two axes of the CCA explained 52.4% of the relation between species and environmental variables, indicating that the hydrological period is determinant in the seasonal variation of the fish. Thus, the understanding of the hydrological variables along with the fishing resources, are subsidies for the better management of the activity. Keywords: Hydrology, Tapajos River, Fishery.