Pescando funções: atributos funcionais explorados pela pesca através do tempo

Abstract

As human civilizations developed and invested in technology, fishing became one of the greatest threats to marine ecosystems, impacting the ecological functions mediated by trait species. However, the exploitation of functional traits over time have never been assessed. Here we investigated the functional spectrum of marine vertebrate taxa exploited in south-southeast Brazilian coast in three different periods: the Shellmounds (8,720 – 230 years BP), the Colonial (1500 – 1966) and the Current period (1967 – 2015). A functional trait space analysis together with kernel density estimates revealed that the full spectrum of functional traits was fished over time. We identified 423 exploited taxa, of which 56 were exploited in all periods. Over time, fisheries have been functionally selective by targeting habitat specialists, invertivorous and macrocarnivorous taxa, with medium and large body size, benthopelagic and pelagic habits. Currently, fishing technology has boosted the capture of new traits far from the coast, such as planktivorous, sedentary, benthic, solitary, and small-bodied taxa. Fishing the entire functional trait spectrum clearly shows that fishing is an activity unsustainable over the centuries, and may be unfeasible in the future for two reasons: depletion of stocks and ecosystem functioning weakened by the poverty of traits.