We investigated the environmental partitioning and particle characteristics of macro-, meso- and microplastics and their uptake into the mussel, Mytilus edulis. Sediment samples, overlying seawater and mussels from 9 intertidal locations in the South West of England were analysed for abundance and type of microplastic. Micro- and mesoplastic-like particles were found in 88.5% of the 269 mussels sampled, ranging from 1.43 to 7.64 items per mussel. Of these plastic particles, 70.9% were identified as semi-synthetic (mainly modified-cellulose). Mussel microplastic abundance, but not polymer type, was correlated with that of their surrounding sediment, but not with sea-surface microplastic concentration or mussel size for our study sites. We found significant differences in the relative abundance of polymer types and particle sizes between seawater, sediment, and mussels, with mussels over-representing modified-cellulose fibre abundance but under-representing polyvinyl. Mussels contained significantly smaller plastic fragments than their surrounding sediment and shorter fibres than their overlying seawater.

Silver (Ag) is a non-essential metal known to bioaccumulate in aquatic organisms. We determined Ag concentrations in five false killer whales stranded in South America. Silver concentrations (in dry weight basis) range as 6.62–10.78 μg g⁻¹ in liver, 0.008–7.41 μg g⁻¹ in spleen, 0.004–5.71 μg g⁻¹ in testis, 0.757–1.69 μg g⁻¹ in kidney, 0.011–0.078 μg g⁻¹ in lung and < 0.01–0.038 μg g⁻¹ in muscle, whereas in the single samples of uterus and ovary were 0.051 and 0.023 μg g⁻¹; respectively. Overall, Ag concentration in liver and kidney exceeded the cetacean toxic thresholds, proposed as “unhealthy concentrations” and “critically dangerous” in liver and kidney. These results warrant further eco-toxicological studies, to examine biological effects of elevated silver levels for individuals and to assess the species' conservation status with respect to marine pollution.

Following the Deepwater Horizon (DWH) spill, oil residues were found in all five Gulf states of the United States (Texas, Louisiana, Mississippi, Alabama and Florida). However, only a small amount was found in Texas, leading to speculation that it may have arrived there via ship through bilge water instead of naturally via currents. We report on a numerical modeling effort to simulate surface drifters during and after the DWH spill to demonstrate that surface water parcels – and therefore oil carried by those parcels – could reasonably have reached Texas waters at the appropriate time and location from known oiled locations without human interference. We additionally give context for the conditions in 2010 through a study of summer connectivity with the Galveston Bay coastline, which shows that in some years oil from the DWH pipe likely would not have reached Texas.

During 1960–94 tailings from an ilmenite mine in southwest Norway were placed in sea deposits in a sheltered fjord and a more exposed coastal basin. In 2015 both deposit sites were sampled to assess the state of metal contamination and macrobenthic communities 20–30 years after deposition was ended. The results showed that nickel and copper still exceeded environmental quality standards in sediment and pore water from the 0–1 cm layer, and fluxes of nickel, copper and cobalt to the overlying water was high compared to adjacent reference stations. Fauna communities were classified as good, but moderate disturbance was recorded along an environmental gradient defined by depth and tailings-induced parameters such as particle size and copper. The results were interpreted in terms of current discharges, biological sediment reworking and near-surface leaching of metal sulphides. No evidence was found for recycling of metals from tailings buried below the bioturbated surface layer.

The Eastern Arabian Sea (EAS) is affected by oil pollution, as often evidenced by the presence of tarballs along the West Coast of India (WCI). Tarball samples collected during May 2017 along the Goa coast were subject to biomarker fingerprints, and the results matched with Bombay High (BH) oil fingerprints. The present study primarily aims at identifying the potential minor spill areas using Sentinel-imagery. Interestingly, repeated occurrence of oil spills detected at two locations, perfectly matched with BH platforms. The simulated Lagrangian trajectories also depict that tarball particles have originated from those detected locations. In 2017 alone, the quantity of spilled oil was estimated to be 129,392 l. However, spills detected offshore regions of Kachchh and Mangalore were found to be caused by ships. This is the first comprehensive study, tracking the oil pollution sources in the EAS through multi-technique approach - chemical, remote sensing and numerical modeling.

Bryozoans are the major component of marine macro-fouling communities. In the study, the relations between bryozoan species and environmental variables were investigated at seven stations along the Aegean coast in August and December 2015. Constant bryozoan species in both sampling periods were Bugula neritina, Amathia verticillata, Shizoporella errata, Cryptosula pallasiana and Celleporaria brunnea. Their relationship with physico-chemical variables (Temperature, salinity, pH, dissolved oxygen, ammonium, nitrite and nitrate nitrogen, orthophosphate phosphorous, total phosphate, chlorophyll-a) were analysed by means of logistic regression analysis. The result showed that temperature with B. neritina; NH4-N, oPO4-P and TPO4-P with A verticillata; dissolved oxygen concentrations with S. errata and C. brunnea were positively related (p < 0.05).

In oil spill models, vertical mixing due to turbulence is commonly modelled by random walk. If the eddy diffusivity varies with depth, failing to take the derivative of the diffusivity into account in the random walk scheme will lead to incorrect results. Depending on the diffusivity profile, the result may be either over- or underprediction of the amount of surfaced oil. The importance of using consistent random walk schemes has been known for decades in, e.g., the plankton modelling community. However, it appears not to be common knowledge in the oil spill community, with inconsistent random walk schemes appearing even in recent publications. We demonstrate and quantify the error due to inconsistent random walk, using a simplified oil spill model, and two different diffusivity profiles. In the two cases considered, a commonly used inconsistent scheme predicts respectively 58% and 176% the amount of surface oil, compared to a consistent scheme.

This study investigated the removal of microplastics from different treatment stages in three WWTPs and examined the performance of tertiary treatment that was done by coagulation and different technologies such as ozone (WWTP-A), membrane disc-filter (WWTP-B), and rapid sand filtration (WWTP-C). The results showed that the primary and secondary treatment processes effectively remove microplastics from wastewater with efficiencies ranging between 75% and 91.9%. The removal efficiency increased further to >98% after tertiary treatment. Microbeads and fragments were the major types of microplastics found in all wastewater sampling points. Microbeads found in the wastewater samples were classified as primary microplastics, that mainly came from personal care products, whereas secondary microplastics consisted of fragments, fibers, and sheets that were generated mainly due to fragmentation of larger plastics. Microplastics were still found in a high concentration in the final effluent, especially from WWTP-B, which is discharged into the Geumho river.

This research attempted to investigate the plant/soil concentration ratios (CRs) of ¹³⁷Cs and ⁴⁰K in plants that grow on the Anzali Lagoon of the Caspian coast, Iran. The activity concentrations of ¹³⁷Cs and ⁴⁰K were measured in soil samples, annual plants (Echinochloa crus-galli, Digitaria sanguinalis, and Trifolium repens), and perennial plants (Phragmites australis, and Cynodon dactylon). The relationship of activity concentration with soil particle density, and pH of soil samples, CR, and ¹³⁷Cs/⁴⁰K discrimination factor (DF) were determined. The activity concentration of ¹³⁷Cs in the soil, annual plants, and perennial plants ranged between 12- and 124 (Bq/kg dry weight), 2- and 17 (Bq/kg dw), and 2 - and 14 (Bq/kg dw), respectively. The geometric mean (GM) values of DF in annual and perennial plants were 0.57 and 0.55, respectively. The CR for ¹³⁷Cs and ⁴⁰K varied as a non-linear relation in annual plants and perennial plants. This study showed that the CRs for ¹³⁷Cs in annual plants were higher than the CRs for perennial plants.

The effect of increasing ocean water temperature on morpho-functional traits of Antarctic marine species is under intense attention.In this work, we evaluated the effects of acute heat stress on the gills of the Antarctic haemoglobinless Chionodraco hamatus and the red blooded Trematomus bernacchii in terms of morphology, heat shock response, antioxidant defense and NOS/NO system. We showed in both species that the exposure to high temperature (4 °C) induced structural alterations, such as epithelial lifting and oedema of secondary lamellae. By immunolocalization we also observed that HSP-90, HSP-70, Xantine Oxidase, Heme Oxigenase and NOS are expressed in both species under control conditions. After heat stress the signals increase in C. hamatus being absent/or reduced in T. bernacchii. Our preliminary results suggest a specie-specific morpho-functional response of the gills of the two Antarctic teleosts to heat stress.