Long‐ term effects of water quality on the freshwater bivalve Diplodon chilensis (Unionida: Hyriidae) caged at different sites in a North Patagonian river (Argentina)

YUSSEPPONE, MARÍA S.; BIANCHI, VIGINIA A.; CASTRO, JUAN M.; LUQUET, CARLOS M.; SABATINI, SEBASTIÁN E.; RÍOS DE MOLINA, MARÍA C.; ROCCHETTA, IARA

ECOHYDROLOGY

JOHN WILEY & SONS INC

Año: 2020 vol. 13

1936-0584

An in-situ experiment was performed to study metabolic responses of the freshwater mussel Diplodon chilensis towater contaminated by leachates from an open dump and cattle activity, in order to analyze both the effects ofthose contaminants on aquatic environments and the potential use of a native bivalve to evaluate the effects ofanthropic influence and eutrophication. Bivalves from a reference site were cage-transplanted to a control site(site A) and to a temporal water pond (site B) over 30 and 60 periods. Water quality analyses revealed that thesite B was affected by anthropogenic influence. Mussel's hemocytes from site B showed 50% lower reactiveoxygen species production and 130% higher lysosomal membrane stability in the site B mussels. In addition, nooxidative stress was evident in gills, despite the elevated copper and iron concentrations recorded in the site Bwater samples (CuB = 0.3350 ± 0.0636 mg. L−1 vs. CuA = 0.0045 ± 0.0007 mg. L−1;FeB = 3.8650 ± 0.4031 mg. L−1 vs. FeA = 0.0365 ± 0.0049 mg. L−1). In contrast, the adductor muscleaccumulated more Fe (~10?20-fold) than the gills and showed signs of oxidative stress, e.g. superoxide dismutaseactivity and TBARS levels were increased by 10% were 34%, respectively, in the site B compared withthe site A after 60 days of exposure. Additionally, the adductor muscle showed signs of anaerobic metabolismactivation. Cu is accumulated in gills from both sites? individuals, at 60 days, in concordance with the increase inthe activity of the cu-containing enzyme cytochrome-c-oxidase. There was a reduction in the overall conditionand digestive gland index in bivalves exposed at site B, associated with diminished levels of lipid and proteincontents. Metal-pollution and eutrophication affects D. chilensis metabolism and is associated to tissue-specificexposure, anaerobic metabolism and general energetic condition depletion.