Eleven organophosphate esters (OPEs) in air and seawater were investigated from the Northwestern Pacific to the Arctic Ocean. The concentration of Σ₁₁OPEs in air and seawater ranged from 231.56 to 1884.25 pg/m³ and from 8.47 to 143.45 ng/L, respectively. Halogenated OPEs dominated in both two media. The slight decreasing trend was observed for OPEs in gaseous air, no obvious trend for particle-bound OPEs and in seawater. The net air-seawater exchange flux ranged from −792.68 to 590.29 pg/m²/day. The dry deposition flux ranged from 16.4 to 185 ng/m²/day with high value observed at the Bering Strait (64.70 ng/m²/day). The relationship between temperature and OPEs particle-bound fractions suggests that temperature might be a driving factor of OPEs long-range atmospheric transport (LRAT). This research highlighted that OPEs are subject to LRAT from the Asian continent to the northwestern Pacific and Arctic Oceans and demonstrated the “sink” in polar regions of OPEs atmospheric transportation.

Core sediment samples were collected from five mangrove ecosystems along northern Kerala coast (Kunjimangalam: S1, Pazhayangadi: S2, Pappinissery: S3, Thalassery: S4, and Kadalundi: S5) to assess the status of heavy metal pollution. S1 recorded comparatively lower metal concentration at surface (except Pb) due to low organic content and sandy texture, while the reverse was true for S3. Higher metal contents were recorded at S5 (0–5 cm), which was attributed to its unique biogeochemical behavior. Enrichment factor and geoaccumulation index indicated moderate enrichment for Cd, and the pollution load index revealed progressive deterioration of sediment quality at S5 (0–5 cm). There was no harmful effect of trace metals on biological community (except Ni) according to Sediment Quality Guidelines. Major processes controlling trace metal accumulation in these systems are diagenetic processes, precipitation of heavy metals as sulfides, and the presence of Fe, Mn-oxy hydroxides, which act as adsorption sites for other metals.

This paper increases knowledge on litter transfer from sediments towards the trophic web throughout sea cucumbers, key protected benthic species. In October, sediment and holothurian samples from seventeen sampling sites from Croatian Islands characterized by different levels of protection (Silba n = 7; Telašćica MPA n = 10) were collected. Collected particles ranged in sediments within 113.4–377.8 items/kg d.w., and in holothurians within 0.6–9.4 items/animal, showing sizes within 1.4–10,493 μm. In holothurians, cellulose and cellulose acetate (non-synthetic materials) mean percentages were within 5.0–12.7% of the total amount of particles. Nylon fibres ranged within 0–26.7%; while PP, PE, PA, and PS% were more abundant than in sediments. Among factors of variability tested, “island group” and “level of protection” resulted to affect plastic composition in sediments. Otherwise, other environmental factors (i.e. orientation, morphology of sampling site, P. oceanica) were significantly related to chemical composition of microplastic ingested by holothurians.

Diluted bitumens are produced by adding lower viscosity diluent to highly viscous bitumen to enable it to flow through pipelines and thus may behave differently than conventional oils when spilled into coastal seawater. Simulated surface spills using three different diluted bitumen products were carried out in May, July and November and water column hydrocarbons were monitored over a 14 day period. Volatile and total petroleum hydrocarbons varied in the water column depending on season and type of diluent. In summer, products diluted with synthetic crude or a mixture of condensate and crude released droplets into the water column. Diluted bitumen did not sink to the bottom of the enclosures with surface slicks showing a range of weathering after 14 d. With most of the diluted bitumen product remaining on the surface for 14 d, a rapid conventional clean up response may be effective in low energy, coastal waters.

Complementary microbial and geochemical assessment techniques investigated the biodegradation of PAHs and alkanes in salt marshes impacted by crude oil following the Macondo spill. Contamination was observed in the top 10 cm of the marsh profile based on PAH analysis and measurement of the δ¹³C signature of impacted marsh soils. Measurement of evolution of ¹³C depleted CO₂ indicated mineralization of crude oil ranging from 2.7–12.1 mg CO₂-C/m²-hr. Changes in weathering ratios of alkylated phenanthrenes and dibenzothiophenes indicated loss of these 3-ring PAHs consistent with biodegradation. A diverse microbial population was observed at both locations dominated by Gammaproteobacteria and including known hydrocarbon degraders such as Marinobacter and Alcanivorax. There was shared richness between sites and across seasons but results suggested substantial turnover of phylotypes in space and time. Biodegradation of alkanes and alkylated PAHs occurred when oxygen was provided in laboratory reactors but not in the absence of oxygen.

We investigated the growth and nutrient uptake of Myriophyllum spicatum under different nutrient conditions and evaluated its implications for ecosystem services in an enclosed area of Jinshan. The specific growth rate ranged from 1.29%–4.37%/day, and the dissolved inorganic carbon and nitrogen, and phosphorus uptake rates were 1.30–1.62, 0.040–0.453, and 0.003–0.027 mg/(g∙day), respectively, under different nutrient conditions. The O₂-production and carbon-sequestration efficiencies in the field were 154.30 and 1.25 mg/(g DW∙h), respectively. The average removal efficiencies of NH₄⁺-N, NO₃⁻-N, NO₂⁻-N, and PO₄³⁻-P were 43.05%, 97.03%, 64.26%, and 59.24%, respectively, in M. spicatum-cultivated areas compared with in the open sea. Harvesting of M. spicatum removed 12,936.87, 1289.97 and 114.81 kg of carbon, nitrogen, and phosphorus, respectively, from seawater in Jinshan in Nov, 2018. In conclusion, M. spicatum is a good candidate for integrated macrophyte/animal multi-trophic aquaculture in terms of nutrient extraction and economic diversification in low-salinity environments.

In vitro methods have gained rising importance in ecotoxicology due to ethical concerns. The aim of this study was to assess the single and combined in vitro effects of gold, as nanoparticle (AuNPs) and ionic (Au⁺) form, and the pharmaceutical gemfibrozil (GEM). Sparus aurata liver organ culture was exposed to gold (4 to 7200 μg·L⁻¹), GEM (1.5 to 15,000 μg·L⁻¹) and combination 80 μg·L⁻¹ gold +150 μg·L⁻¹ GEM for 24 h. Endpoints related with antioxidant status, peroxidative/genetic damage were assessed. AuNPs caused more effects than Au⁺, increasing catalase and glutathione reductase activities and damaging DNA and cellular membranes. Effects were dependent on AuNPs size, coating and concentration. GEM damaged DNA at an environmentally relevant concentration, 1.5 μg·L⁻¹. Overall, the effects of the combined exposures were higher than the predicted, based on single exposures. This study showed that liver culture can be a useful model to study contaminants effects.

Seabirds are used as bioindicators of marine ecosystems, especially for quantifying and tracking pollution sources. The objective of this study was to evaluate the contamination in feathers of young kelp gulls by lead (Pb), chromium (Cr), mercury (Hg) and zinc (Zn) on three islands of southern Brazil. The highest values for Pb (2.1310 μg g⁻¹) and Hg (0.0010 μg g⁻¹) were observed in Lobos. Zn was common in all samples with a median around 41.7487 μg g⁻¹ and Cr values were below the quantification limit (0.0300 μg g⁻¹). The Kruskal-Wallis test indicated significant differences in Pb (H = 21.84; p < 0.05) and Zn (H = 958.80; p < 0.05), but no differences were observed in Cr (H = 3.08; p < 0.05) and Hg (H = 3.0; p < 0.05). This study was important to show the impact of trace element pollutants on the seabird communities and oceans.

Plastic pollution has a detrimental effect on marine environments, and there is limited information regarding its ingestion by biota, which is the primary consumer. Therefore, this research aims to assess microplastic ingestion by blue panchax fish (Aplocheilus sp.). To achieve this, microplastics were extracted and identified from Ciliwung estuary, coastal waters in North Jakarta, and the Aplocheilus sp. Its various forms and sizes were found in river flow (9.37 ± 1.37 particles/m³), coastal waters (8.48 ± 9.43 particles/m³), and in 75% samples of Aplocheilus sp. (1.97 particles/individual). The microplastic size which was of highest concentration in Aplocheilus sp. was relatively small, ranging from 300 to 500 μm. This small size indicates that the fish has difficulty in distinguishing between their food and the microplastics. Further, there was a possibility of the absorption of other pollutants by the plastics. Therefore, an in-depth study on the effects of plastic ingestion on aquatic life, biomagnification, exposure, chemical toxicity, and socio-economy is recommended.

Twenty-five offshore sediment samples were collected after the Gaja cyclone to evaluate the sediment quality in terms of its metal concentration. The samples were examined for organic matter, textural characteristics, calcium carbonate, and trace metals (Fe, Mn, Ni, Co, Cu, and Cr). The geo-accumulation index, enrichment factor, contamination factor, and pollution load index revealed that the study area was highly contaminated with Cu, Zn, and Co. Reasonable to extensive contamination was observed for Fe, Cr, and Ni, whereas Mn was under the uncontaminated category. Statistical analyses revealed that the contamination of Cu, Zn, and Ni are mainly originated from human activities such as boat navigation, fuel combustion, and tourism. Cyclones such as Gaja cause ecological disturbances of the terrestrial and transitional environments and also increase the level of offshore contamination by flooding the contaminated coastal landforms and transporting the contaminants to the sea.