Ecotoxicological effects of chemical contaminants adsorbed to microplastics in the clam Scrobicularia plana

Although microplastics (MPs) are distributed globally in the marine environment, a great deal of unknowns relating to their ecotoxicological effects on the marine biota remains. Due to their lipophilic nature, microplastics have the potential to adsorb persistent organic pollutants present in contaminated regions, which may increase their detrimental impact once assimilated by organisms. This study investigates the ecotoxicological effects of exposure to low-density polyethylene (LDPE) microplastics (11-13 beta m), with and without adsorbed contaminants (benzo[a]pyrene- BaP and perfluorooctane sulfonic acid-PFOS), in the peppery furrow shell clam, Scrobicularia plana. Environmentally relevant concentrations of contaminants (BaP-16.87 +/- 0.22 mu g g(-1) and PFOS-70.22 +/- 12.41 mu g g(-1)) were adsorbed to microplastics to evaluate the potential role of plastic particles as a source of chemical contamination once ingested. S. plana were exposed to microplastics, at a concentration of 1 mg L-1, in a water-sediment exposure setup for 14 days. Clams were sampled at the beginning of the experiment (day 0) and after 3, 7, and 14 days. BaP accumulation, in whole clam tissues, was analyzed. A multi-biomarker assessment was conducted in the gills, digestive gland, and haemolymph of clams to clarify the effects of exposure. This included the quantification of antioxidant (superoxide dismutase, catalase, glutathione peroxidase) and biotransformation (glutathione-Stransferases) enzyme activities, oxidative damage (lipid peroxidation levels), genotoxicity (single and double strand DNA breaks), and neurotoxicity (acetylcholinesterase activity). Results suggest a potential mechanical injury of gills caused by ingestion of microplastics that may also affect the analyzed biomarkers. The digestive gland seems less affected by mechanical damage caused by virgin microplastic exposure, with the MPs-adsorbed BaP and PFOS exerting a negative influence over the assessed biomarkers in this tissue.JPI Oceans FCT JPIOCEANS/0005/2015 JPI Oceans (BELSPO) JPI Oceans (FWO) JPI Oceans (FORMAS) JPI Oceans (SwAM) FCT UID/MAR/00350/2013info:eu-repo/semantics/publishedVersio

Development and validation of an experimental life support system for assessing the effects of global climate change and environmental contamination on estuarine and coastal marine benthic communities

An experimental life support system (ELSS) was constructed to study the interactive effects of multiple stressors on coastal and estuarine benthic communities, specifically perturbations driven by global climate change and anthropogenic environmental contamination. The ELSS allows researchers to control salinity, pH, temperature, ultraviolet radiation (UVR), tidal rhythms and exposure to selected contaminants. Unlike most microcosms previously described, our system enables true independent replication (including randomization). In addition to this, it can be assembled using commercially available materials and equipment, thereby facilitating the replication of identical experimental setups in different geographical locations. Here, we validate the reproducibility and environmental quality of the system by comparing chemical and biological parameters recorded in our ELSS with those prevalent in the natural environment. Water, sediment microbial community and ragworm (the polychaete Hediste diversicolor) samples were obtained from four microcosms after 57 days of operation. In general, average concentrations of dissolved inorganic nutrients (NO3 ; NH4 + and PO4 3) in the water column of the ELSS experimental control units were within the range of concentrations recorded in the natural environment. While some shifts in bacterial community composition were observed between in situ and ELSS sediment samples, the relative abundance of most metabolically active bacterial taxa appeared to be stable. In addition, ELSS operation did not significantly affect survival, oxidative stress and neurological biomarkers of the model organism Hediste diversicolor. The validation data indicate that this system can be used to assess independent or interactive effects of climate change and environmental contamination on benthic communities. Researchers will be able to simulate the effects of these stressors on processes driven by microbial communities, sediment and seawater chemistry and to evaluate potential consequences to sediment toxicity using model organisms such as Hediste diversicolor.This study was supported by the Centre for Environmental and Marine Studies (CESAM), the Foundation for Science and Technology (FCT, Portugal) PTDC/AAC-CLI/107916/2008 (http://alfa.fct.mctes.pt) and the European Regional Development Fund (ERDF) through COMPETE-(FCOMP-01-0124- FEDER-008657). Francisco J.R.C. Coelho and Rui J. M. Rocha were supported by a PhD scholarship (SFRH/BD/46322/2008 and SFRH/BD/46675/2008, respectively) funded by FCT (QREN-POPH – Type 4.1 – Advanced Training, subsidized by the European Social Fund and national funds MCTES). We thank Jos e Ferreira from EpArq, Aveiro University for graphical design of the ELSS

The ‘Coral Bulker’ Fuel Oil Spill on the North Coast of Portugal: Spatial and Temporal Biomarker Responses in Mytilus galloprovincialis

In December 2000, the ship ‘Coral Bulker’ ran aground at the entrance of the port of Viana do Castelo (North–west coast of Portugal). A large amount of fuel oil was spilled and part of it reached the shore. To evaluate the spatial and temporal impact of this oil spill, a field study, and several laboratory toxicity tests were performed using Mytilus galloprovincialis as biological indicator of environmental contamination and the biomarkers glutathione S-transferases (GSTs) and acetylcholinesterase (AChE) as indicative criteria. Fifteen days after the oil spill, mussels collected at stations located near the ship presented higher and lower values of GSTs and AChE activity, respectively. These results, and those obtained in the laboratory toxicity tests, evidence that these biomarkers were sensitive indicators of exposure to this kind of pollution and were able to monitor a spatial impact of the oil spill of at least 10 km, confirming the higher level of contamination near the ship and a contamination gradient along the sampling stations. One year after the accident, such a contamination gradient was no longer evident. This study highlight the potential suitability of a biomarker approach for assessing spatial and temporal impacts of marine pollution accidents, such as fuel oil spills, suggesting the inclusion of these biomarkers in risk assessment studies, as cost-effective and early warning recognized tools. Major advantages and limitations of the biomarker approach used in this study are further discussed