Microplastics (MPs) were characterized in surficial marine sediment (n = 36) and mussel (n = 29) samples collected along the British Columbia (BC) coast, Canada, using visual identification and Fourier Transform Infrared Spectrometry. MPs counts averaged 32.6 ± 5.3 particles per kg in sediment and 0.38 ± 0.04 particles per individual mussel (0.24 ± 0.04 /g of tissue). Victoria Harbour and the North Coast (Prince Rupert area) were MP hotspots, likely resulting from a combination of local sources and oceanographic conditions. Microfibers <1000 μm dominated the pattern in both matrices (61.1 % in sediment; 65.4 % mussels) highlighting the suspected role of textiles in the widespread distribution of MPs in the marine environment. Overall, polyester was dominant in sediment and mussels (54.1 % and 63.5 %, respectively), followed by polyethylene (16.2 % and 11.5 %, respectively). This is the first report of MPs in sediment and mussels along the coast of BC using standardized methods.

peer reviewed | Contaminated land burdens the economy of many countries and must be dealt with. Researchers have published thousands of documents studying and developing soil and sediment remediation treatments. Amongst the targeted pollutants are the polycyclic aromatic hydrocarbons (PAHs), described as a class of persistent organic compounds, potentially harmful to ecosystems and living organisms. The present paper reviews and discusses three scientific trends that are leading current PAH-contaminated soil/sediment remediation studies and management. First, the choice of compounds that are being studied and targeted in the scientific literature is discussed, and we suggest that the classical 16 US-EPA PAH compounds might no longer be sufficient to meet current environmental challenges. Second, we discuss the choice of experimental material in remediation studies. Using bibliometric measures, we show the lack of PAH remediation trials based on co-contaminated or aged-contaminated material. Finally, the systematic use of the recently validated bioavailability measurement protocol (ISO/TS 16751) in remediation trials is discussed, and we suggest it should be implemented as a tool to improve remediation processes and management strategies.

Surfactants, after use, enter the environment through diffuse and point sources such as irrigation with treated and non-treated waste water and urban and industrial wastewater discharges. For the group of non-ionic synthetic surfactant alcohol ethoxylates (AEOs), most of the available information is restricted to the levels and fate in aquatic systems, whereas current knowledge of their behavior in soils is very limited. Here we characterize the behavior of different homologs (C12-C18) and ethoxymers (E03, E06, and E08) of the AEOs through batch experiments and under unsaturated flow conditions during infiltration experiments. Experiments used two different agricultural soils from a region irrigated with reclaimed water (Guadalete River basin, SW Spain). In parallel, water flow and chemical transport were modelled using the HYDRUS-1D software package, calibrated using the infiltration experimental data. Estimates of water flow and reactive transport of all surfactants were in good agreement between infiltration experiments and simulations. The sorption process followed a Freundlich isotherm for most of the target compounds. A systematic comparison between sorption data obtained from batch and infiltration experiments revealed that the sorption coefficient (K-d) was generally lower in infiltration experiments, performed under environmental flow conditions, than in batch experiments in the absence of flow, whereas the exponent (beta) did not show significant differences. For the low clay and organic carbon content of the soils used, no clear dependence of K-d on them was observed. Our work thus highlights the need to use reactive transport parameterization inferred under realistic conditions to assess the risk associated with alcohol ethoxylates in subsurface environments. (C) 2020 The Authors. Published by Elsevier Ltd.

Anti-sea lice pesticides, used in the salmonid aquaculture industry, are a growing environmental concern due to their potential to adversely affect non-target crustaceans. Azamethiphos and deltamethrin are two bath treatment pesticides used on salmon farms in Norway, however, limited information is available on their impact on European lobster (Homarus gammarus) larvae in the Norwegian marine environment. Here, we firstly report the lethal (LC50) and effective (EC50) concentrations of azamethiphos and deltamethrin for stage I and stage II larvae, following 1-h exposures. Using a hydrodynamic model, we also modelled the dispersal of both compounds into the marine environment around selected Norwegian farms and mapped the potential impact zones (areas that experience LC50 and EC50 concentrations) around each farm. Our data shows that azamethiphos and deltamethrin are acutely toxic to both larval stages, with LC50 and EC50 values below the recommended treatment concentrations. We also show that the azamethiphos impact zones around farms were relatively small (mean area of 0.04–0.2 km2), however deltamethrin impact zones covered much larger areas (mean area of 21.1–39.0 km2). These findings suggest that deltamethrin poses a significant risk to European lobster in the Norwegian marine environment while the impact of azamethiphos may be less severe. | publishedVersion

Embargo until 01 March 2022 | Microplastics were sampled in open surface waters by using a manta trawl and an in-situ filtering pump. A total of 24 trawl samples and 11 pump samples were taken at 12 locations around Sweden. Overall, the concentration of microplastic particles was higher in pump samples compared to trawl samples. The median microplastic particle concentration was 0.04 particles per m−3 for manta trawl samples and 0.10 particles per m−3 in pump samples taken with a mesh size of 0.3 mm. The highest concentrations were recorded on the west coast of Sweden. Fibers were found in all samples and were also more frequent in the pump samples. Even higher concentrations of fibers and particles were found on the 0.05 mm pump filters. Using near-infrared hyperspectral imaging the majority of the particles were identified as polyethylene followed by polypropylene. | acceptedVersion

Chlordecone, applied on soils until 1993 to control banana weevil, has polluted water resources in the French West Indies for more than 40 years. At the watershed scale, chlordecone applications were not homogenous, generating a spatial heterogeneity of the pollution. The roles of climate, hydrology, soil, agronomy, and geology on watershed functioning generate a temporal heterogeneity of the pollution. This study questions the interactions between practices and the environment that induce such variability. We analyzed hydrological and water pollution datasets from a 2-year monitoring program on the Galion watershed in Martinique (French West Indies). We conjointly analyzed (i) weekly chlordecone (CLD) concentration monitored on 3 river sampling sites, (ii) aquifer piezometric dynamics and pollutions, and (iii) agricultural practices on polluted soils. Our results showed that chlordecone pollution in surface waters are characterized by annual trends and infra-annual variations. Aquifers showed CLD concentration 10 times higher than surface water, with CLD concentration peaks during recharge events. We showed strong interactions between rainfall events and practices on CLD pollution requiring a systemic management approach, in particular during post-cyclonic periods. Small sub-watershed with high CLD pollution appeared to be a substantial contributor to CLD mass transfers to the marine environment via rivers and should therefore receive priority management. We suggest increasing stable organic matter return to soil as well as external input of organic matter to reduce CLD transfers to water. We identified hydrological conditions—notably drying periods—and tillage as the most influential factors on CLD leaching. In particular, tillage acts on 3 processes that increases CLD leaching: organic matter degradation, modification of water paths in soil, and allophane clay degradation.

Increased knowledge about the fate and behaviour of weathered oil in different sea ice conditions is essential for our ability to model oil spill trajectories in ice more precisely and for oil spill response decision making in northern and Arctic areas. As part of the 3-year project: “Fate, Behaviour and Response to Oil Drifting into Scattered Ice and Ice Edge in the Marginal Ice Zone”, a novel wave and current flume was built to simulate these processes in the laboratory. This paper discusses some of the findings from this project, which included Marine Gas Oil and four Norwegian crude oils. All crude oils were weathered prior to testing, simulating having drifted on the sea surface for a period (tentatively 1–3 days) before encountering ice. The build-up of oil drifting against an ice barrier and horizontal and vertical migration of oil droplets under solid ice and in frazil ice was studied. | publishedVersion

Embargo until 09 October 2020 | The ubiquity and high bioavailability of microplastics have an unknown risk on the marine environment. Biomonitoring should be used to investigate biotic impacts of microplastic exposure. While many studies have used mussels as indicators for marine microplastic pollution, a robust and clear justification for their selection as indicator species is still lacking. Here, we review published literature from field investigations and laboratory experiments on microplastics in mussels and critically discuss the suitability and challenges of mussels as bioindicator for microplastic pollution. Mussels are suitable bioindicator for microplastic pollution because of their wide distribution, vital ecological niches, susceptibility to microplastic uptake and close connection with marine predators and human health. Field investigations highlight a wide occurrence of microplastics in mussels from all over the world, yet their abundance varies enormously. Problematically, these studies are not comparable due to the lack of a standardized approach, as well as temporal and spatial variability. Interestingly, microplastic abundance in field-collected mussels is closely related to human activity, and there is evidence for a positive and quantitative correlation between microplastics in mussels and surrounding waters. Laboratory studies collectively demonstrate that mussels may be good model organisms in revealing microplastic uptake, accumulation and toxicity. Consequently, we propose the use of mussels as target species to monitor microplastics and call for a uniform, efficient and economical approach that is suitable for a future large-scale monitoring program. | acceptedVersion