Diversidade taxonômica e funcional de assembleias de peixes em lagos de várzea estabelecidos pelo acesso livre e restrito à pesca na Amazônia Central

Abstract

Understanding the impact of fishing activity on fish assemblages is an important condition for preventing its effects on biodiversity and the functioning of ecosystems. In the Amazon, fishing is the main extractive activity, with a history of overexploitation of fish stocks and conflicts between the different users of the resource. As a result, co-management initiatives have emerged in the region, aimed at zoning and restricting areas to commercial fishing. Here, we assess the effects of fishing on fish diversity, covering multidimensional elements (taxonomic and functional) that can provide complementary answers to the ecological consequences that the activity can have on the environment. To do this, we compared time series in two floodplain lakes, one with free access and the other with restricted access to fishing in two nearby areas in the Central Amazon. Our results show that over the years there has been a decline in taxonomic diversity indices in the open-access lake and an increase in the fishing-restricted lake; a difference in functional composition between the two types of lakes; and an increase in divergence, equitability and functional redundancy indices over the years, which is more pronounced in the open lake. A negative impact of fishing on the functional composition and taxonomic structure of fish assemblages was demonstrated at a local level. On the other hand, there is a recovery in the restricted access environment as the years of restriction go by, which may have been more pronounced in the open lake.