Characterization and spatiotemporal dynamics of the ichthyofauna of two tidal containment zones on the Brazilian Amazon coast

This study aimed to characterize spatiotemporal variations in the ichthyofauna of two tidal containment zones in Maranhão state, Brazil. Monthly, collections were carried out in the containment zones of São Luís and São José de Ribamar, with samplings performed after the peak of the lowest tide (transition between low tide and high tide).Physicochemical parameters such as water salinity, temperature, transparency, and precipitation were measured monthly. A gill net (25-mm mesh) was used to capture fish. A total of 169 ichthyic individuals were captured and identified in the coastal containment areas of São Luís and São José de Ribamar. The orders Perciformes (41%) and Siluriformes (13.6%) were the most representative in terms of number of species. According to analysis of the t-test, there were significant seasonal and spatial variations in the number of organisms (p < 0.05), with the highest catches in rainy and transitional months. It was possible to identify a variation in niches in both study areas, the influence of physicochemical parameters on ichthyofaunal communities of São Luís and São José de Ribamar, and the effects of the containment structures on fish biomass and diversity, mainly in São Luís.