Influência da pesca e de um predador de topo de cadeia sobre a diversidade funcional das assembleias de peixes em lagos de várzea manejados

Abstract

Several factors can compromise the functioning of an aquatic ecosystem, including highly exploitative fishing practices and predation by carnivorous species. Studies estimating the effect of these factors on fish assemblages in floodplain areas focus on taxonomic biodiversity, which loses community level information and leaves gaps in the understanding of the aquatic ecosystem as a whole. The objective of this work was to evaluate the seasonal effect of fishing and apex predation on the functional structure of fish assemblages in floodplain lakes managed on the island of Paciência - Iranduba-AM using three complementary functional indexes (Richness, Evenness, and Divergence). We found that the pre-defined lake categories in the fishing agreements (management lakes ≠ commercial use lakes) and the flood pulse (flood ≠ low water season) exert influence on functional richness and functional equitability, respectively. The increase in the abundance of a top-chain predator did not influence the functional structure of fish assemblages. Therefore, the results support the efficacy of the fishing agreement implemented on the island of Paciência as a strategy to maintain biodiversity in the floodplain areas.