Abstract
AbstractThe Rio Doce estuary was critically impacted in 2015 by the world’s largest mining tailing spill, with still unclear long-term effects. Here we present a long-term (2015 to 2020) assessment of estuarine benthic assemblages, where Annelida and Mollusca were dominant (52.6% and 26.3%, respectively). Our results demonstrated that the density and richness of benthic taxa decreased in response to an increase in potentially toxic elements concentrations, suggesting a chronic pollution effect that lasted for at least 4.2 years in the estuary. Our data demonstrated that despite the decline in sediment potentially toxic elements concentration over time, there was a continued low habitat quality for the benthic fauna characterized by a reduction of 96% on macroinvertebrate density and 48% on species richness. The long-term impacts on benthic macrofauna highlight that water quality levels can misguide impact assessment programs, and reveal that mine tailings impacts persist for many years in estuarine ecosystems.
Publisher
Cold Spring Harbor Laboratory
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