Marinas have been shown to contribute elevated concentrations of copper (Cu) to marine waters. The Cu can come primarily from antifouling paints which are designed to discourage biofouling of boat hulls. Legislation in Washington State, USA is being developed to limit or regulate the amount and rate of diffusion of Cu from antifouling paints. This study provides baseline data for Cu in five marinas of different configuration and size within Puget Sound, a large fjord estuary. Samples were collected over a year from multiple environmental media. We find strong evidence that Cu accumulates inside marinas to higher concentrations than outside marinas. Marinas that are more enclosed accumulated higher concentrations of Cu than more open marinas. Using a power analysis, we assessed the adequacy of the baseline dataset to measure progress as a result of future legislation towards the reduction of Cu to Puget Sound from marinas.

The Black Sea receives increasing amounts of microplastics from rivers. In this study, we explore options to reduce future river export of microplastics to the Black Sea. We develop five scenarios with different reduction options and implement them to a Model to Assess River Inputs of pollutaNts to seA (MARINA-Global) for 107 sub-basins. Today, European rivers draining into the Black Sea export over half of the total microplastics. In 2050, Asian rivers draining into the sea will be responsible for 34–46% of microplastic pollution. Implemented advanced treatment will reduce point-source pollution. Reduced consumption or more collection of plastics will reduce 40% of microplastics in the sea by 2050. In the optimistic future, sea pollution is 84% lower than today when the abovementioned reduction options are combined. Reduction options affect the share of pollution sources. Our insights could support environmental policies for a zero pollution future of the Black Sea.

Microplastic (MP) pollution in the marine environment is a worldwide issue. There is growing concern of consuming MPs through fish, yet the contamination status of fish collected from deeper waters surrounding Japan remains limited. Here, we presented baseline data on MPs in commercially important fishes from the coastal and offshore waters near Kyushu, Japan (East China Sea). We examined the MPs in the digestive tracts of two pelagic (n = 150) and five demersal species (n = 235). The fish were caught by pole and line, and bottom trawl at different geographical positions. The MPs in pelagic fish (39.1%) were more than in demersal fish (10.3%) and were of larger sizes. Moreover, the MPs correlated with habitat depth and type and species variation in the shape and polymer composition of MPs was observed. The results increase our understanding of the heterogeneous uptake of MPs by fishes.

We investigated the occurrence, origin, and potential ecological risk of dissolved polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyl (PCBs) and organochlorine pesticides (OCPs) in 27 surface water samples collected from a highly anthropized and industrialized area in the Gulf of Gabès (Tunisia, Southern Mediterranean Sea) in October–November 2017. The results demonstrated a wide range of concentrations (ng L⁻¹) with the following decreasing order: Ʃ16 PAHs (17.6–71.2) > Ʃ20 PCBs (2.9–33.7) > Ʃ6 DDTs (1.1–12.1) > Ʃ4 HCHs (1.1–14.8). Selected diagnostic ratios indicated a mixture of both pyrolytic and petrogenic sources of PAHs, with a predominance of petrogenic sources. PCB compositions showed distinct contamination signatures for tetra- to hepta-chlorinated PCBs, characteristic of contamination by commercial (Aroclor) PCB mixtures. The dominant OCP congeners were γ-HCH, 2,4′-DDD and 2,4′-DDE, reflecting past use of Lindane and DDTs in the study area. Agricultural, industrial and domestic activities, as well as atmospheric transport are identified as potential sources of PAHs, PCBs and OCPs in surface waters of the Gulf of Gabès. Toxic equivalents (TEQs) suggested a low carcinogenic potential for PAHs in seawater samples (mean of 0.14 ng TEQ L⁻¹). Evaluation of risk coefficients revealed low risk for PAHs and PCBs, and moderate to severe risk for OCPs.

Rare earth elements (REEs) are increasingly used in various industries worldwide, resulting in their release into aquatic ecosystems. We evaluated the distribution and bioaccumulation of 14 REEs in marine sediments and biotas along the Chinese coasts. The total concentration of REEs (ΣREEs) in sediments was 41.65–170.94 mg/kg. The concentrations of ΣREEs were 1.97–4.77 and 0.62–4.96 mg/kg dry mass (DM) for oysters and mussels. The concentration of total light REEs (ΣLREEs) was higher than the concentration of total heavy REEs (ΣHREEs) at all samples. The bioaccumulation factor (BAF) of ΣLREEs was higher than ΣHREEs and BAF of ΣREE was 0.34–1.49 and 0.25–1.10 for oysters and mussels. The positive correlation between sediments and biotas was higher in mussels than oysters, showing a good potential for being environmental indicators for REEs. The risk of REEs to humans via oysters and mussels consumption could be negligible based on the estimated daily intake.

Global declines in elasmobranch populations resulting from several stressors raises conservation concern. Additionally, apex predators bioaccumulate high concentrations of total mercury (THg), due to biomagnification. Although South Africa is considered one of the top ten contributors of Hg emissions globally, information on Hg concentrations in elasmobranchs is limited. The aim of this study was to evaluate the THg concentrations in 22 species of elasmobranchs along the South African coastline. Concentrations ranged between 0.22 and 5.8 mg/kg in Haploblepharus pictus (dark shysharks) and Rostroraja alba (white skates) on the south coast, respectively. Along the east coast it ranged between 0.21 and 17.8 mg/kg in Mobula kuhlii (shortfin devil rays) and Sphyrna lewini (scalloped hammerheads), respectively. Mercury concentrations on the east coast were in the same range or higher compared to the same species sampled between 2005–10 from the same region, with generally higher concentrations compared to the same species sampled globally.

The objective of the research was to assess the spatio-temporal variation of plastic pellets dispersion in the coastline of Sri Lanka concerning the most tragic maritime accident of the cargo vessel; MV X-Press Pearl. Field sampling was carried in three intensive surveys during May and July 2021. A dry sieving procedure was employed to separate pellets followed by a chemical characterization using Fourier transform infrared spectroscopic analysis. A pellet pollution index (PPI) was determined to compare the degree of pellet pollution. The dispersion peaked two weeks after the spill, with severe pollution levels (PPI: Extreme) found in about 40 % of the coastal stretch from Matara to Kalpitiya. The occurrence of pellets was lower on the Northeast coast of the island compared to the South-west coast. No pellets were recorded from the Northern coast (PPI: Very low). The connection between pollution levels and upper ocean dynamics were explored, with the findings being utilized to track plastic pellets for future spills.

Mercury (Hg) is a global pollutant that is a major public health concern due to its mobility, stability and toxicity behavior in the environment. In this study Hg concentrations were determined in beach sediment samples (n = 43) collected from the South Durban Coast, South Africa. A human health risk assessment was also carried out to comprehend the potential health effects of incidental ingestion/direct contact with contaminated sediments in a recreational setting. Hg concentrations ranged between 0.62 and 4.88 mg kg⁻¹ dw., exceeding all background and regulatory limits. Numerical values of calculated exposure pathways represented dermal contact with the sediments as one of the potential paths in both adults and children. Hazard Index (HI) values were found to be less than unity signifying no adverse health effects. This study validates the critical need for long-term monitoring of Hg in various scenarios in order to incorporate better public health management strategies.

Discarded plastic bag is a main component of marine debris, posing potential threats to marine biota. This study was conducted to assess the potential effects of microplastics on juvenile Lates calcarifer. Fish were exposed via diet to two microplastic types from conventional polyethylene (PE) and biodegradable (Bio) plastic bags for 21 days. Antioxidative enzymes activity, intestinal microbiome and proteome were determined. PE and Bio microplastics were found to accumulate in gastrointestinal tracts, and no mortality was observed. Microplastics exposure did not induce significant antioxidant response except for the glutathione reductase (GR) modulation. Intestinal microbiome diversity decreased significantly in PE group based on Simpson index. Both types of microplastics induced proteome modulation by down-regulating proteins associated with immune homeostasis. Bio microplastics maintained higher intestinal microbial diversity and induced more proteins alteration than PE microplastics. This study provides toxicological insights into the impacts of conventional and biodegradable microplastics on juvenile L. calcarifer.

Abundance of buried microplastics in sand profiles and pellet pollution index at Sarakkuwa beach, at west-coast of Sri Lanka was studied as a case study due to the receival of plastic nurdles and debris from the MV X-Press Pearl ship disaster in May 2021. Sand collected at 7 locations to a depth of 2 m in different depths for a beach segment of 200 × 25 m² during October 2021 and sand samples obtained from beach surface during March 2020 from the same location were analyzed for microplastics. Beach was contaminated with 2–5 mm sized partially pyrolyzed LDPE fragments and nurdles demonstrating a peak abundance of 13.3702 g/kg and1 mm-500 μm sized LDPE fragments up to 2.0 m depth. High concentrations of Mo and Cr were observed in the sand collected in 2021. Sarakkuwa beach is critically polluted by nurdles, partially pyrolyzed microplastics, and toxic elements from ship disaster.