Trophodynamics of arsenic in Nahuel Huapi Lake: Effect of Puyehue-Cordon Caulle volcanic eruption

摘要

Volcanic eruptions are important natural sources of arsenic (As) to the ecosystems. The Nahuel Huapi Lake, in northern Patagonia, was impacted by the eruption of the Puyehue-Cordon Caulle volcanic complex on June 4th, 2011. We investigated food web transfer patterns of As in the most affected shore of the lake (Brazo Rincon) and the effect of volcanic deposition on the As concentrations of the biota. Food web As biodilution was observed, with the highest As concentrations in littoral snail Chilina sp. After the volcanic eruption, significant differences in As concentrations were found only for a few species, including two decapods, a snail and a small fish. The impact of volcanic deposition is associated with increased As in most benthic organisms, reflecting the importance of sediments as a key pathway of; As to the food web.