Immunotoxicity and oxidative stress in the Arctic scallop Chlamys islandica: Effects of acute oil exposure
ABSTRACT With increasing oil exploration in Arctic regions, the risk of an accidental oil spill into the environment is inevitably elevated. As a result, concerns have been raised over the potential impact of oil exposure on Arctic organisms. This study assessed the effects of an acute oil exposure (mimicking an accidental spill) on the immune function and oxidative stress status of the Arctic scallop Chlamys islandica. Scallops were exposed to the water accommodated fraction of crude oil over 21 d (maximum SigmaPAH 163 microg l(-1)) and immune endpoints and oxidative stress parameters were measured. Mortalities were recorded during the exposure and reductions in immunocompetence were observed, with significant impairment of phagocytosis and cell membrane stability. Scallops were also subjected to oxidative stress, with a significant reduction in glutathione levels and induction of lipid peroxidation. After the acute oil exposure had subsided, no recovery of immune function was observed indicating potential for prolonged sublethal effects.
SourceAvailable from: Renato Carreira[Show abstract] [Hide abstract]
ABSTRACT: We evaluated the effects of diesel oil on the bivalve Mytella guyanensis using biomarkers of oxidative stress (glutathione S-transferase, glutathione peroxidase, and reduced glutathione) after an experimental in situ spill in a mangrove area in southern Brazil. A linear model was developed for the Multiple Before-After Control-Impact (MBACI) experimental design to assess the significance of biological responses. Control and impacted sites were sampled seven and two days before as well as two and seven days after the spill. With the exception of a late response of reduced glutathione (GSH) levels on day seven, none of the biomarkers were significantly altered by the impact. This result was attributed to the high environmental variability of the experimental sites combined with a low sensitivity of Mytella guyanensis to diesel oil at short time-scales. The high resistance of M. guyanensis suggests that its antioxidant response is triggered only after a medium- to long-term exposure to contaminants.Ecotoxicology and Environmental Safety 07/2014; 107C:269-275. DOI:10.1016/j.ecoenv.2014.06.001 · 2.48 Impact Factor
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ABSTRACT: Although the variegated scallop Mimachlamys varia seems to be a suitable sentinel species for contaminant monitoring, no study has identified biomarkers in this species. In order to fill this gap, this study conducted an in situ biomarker approach. M. varia were collected in contaminated and uncontaminated areas and responsiveness of oxidative stress and immunological biomarkers was evaluated in the digestive gland. In parallel, 14 trace element concentrations were evaluated in the same organ. Superoxide dismutase activity and malondialdehyde content responded efficiently to in situ contamination when a certain degree of contamination was reached. Laccase-type phenoloxidase showed a high sensitivity but saturation of the response was highlighted for the highest contaminations. Additionally, correlations were found between biomarkers and trace element concentrations. Taken together, results showed that biomarker approach conducted in the digestive gland of M. varia represents a sensitive analytical tool to highlight ecotoxicological issues in coastal marine ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.Aquatic Toxicology 02/2015; 161C. DOI:10.1016/j.aquatox.2015.02.003 · 3.51 Impact Factor
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ABSTRACT: A study on the effect oil pollution under normal and reduced salinity had on blue mussels Mytilus edulis L. from the White Sea in an aquarium-based experiment and in the natural habitat revealed a change in gill total lipids as a compensatory response. The cholesterol concentration and the cholesterol/phospholipids ratio in gills were found to reflect the impact of the environmental factors (oil pollution and desalination), and evidence adaptive changes in the cell membrane structure. An elevated content of storage lipids (chiefly triacylglycerols) in the mussels in the aquarium experiment indicates, first of all, the uptake and accumulation of oil products in gill cells under both normal and reduced seawater salinity, while high triacylglycerols level in gill littoral mussels from 'control' biotope in the Gulf of Kandalaksha is primarily associated with the mussel׳s pre-spawning period.Ecotoxicology and Environmental Safety 09/2014; 110C:103-109. DOI:10.1016/j.ecoenv.2014.08.010 · 2.48 Impact Factor