The purposes of this study were to measure the concentrations of arsenic speciation in shellfish from South China Sea and evaluate the health risk by local residents through shellfish consumption. The median concentrations (in wet weight) of arsenic speciation in shellfish samples were in the following order: AsB (16.0 mg·kg⁻¹) > DMA (1.30 mg·kg⁻¹) > AsV (0.23 mg·kg⁻¹) > AsC (0.08 mg·kg⁻¹) > AsIII (0.05 mg·kg⁻¹) > MMA (0.01 mg·kg⁻¹). Among shellfish species, Mactra mera and Babylonia areolata were found to accumulate iAs and AsB, respectively. The target hazard quotient values of iAs (THQᵢAₛ) in all shellfish samples were lower than 1. However, the carcinogenic risk values of iAs (CRᵢAₛ) in the Mactra mera, Mytilus galloprovincialis and Pinctada margaritifera were beyond the acceptable range, implying that continuous exposure to iAs pollution via the consumption of these shellfish would pose a potential cancer risk to local consumers.

Sandy beaches are part of an integral social-ecological system whose management has to encompass the natural and societal features of the catchment and the adjacent marine area, as well as the beach itself. Using a multi-use and complex beach system in Uruguay, the La Coronilla and Barra del Chuy resort, we interrogate those natural and societal features by employing the DAPSI(W)R(M) cause-consequence-response cycle and pathways. This identifies the Drivers, Activities, Pressures, State change on the natural system, Impacts (on the Welfare of the human system), and the Responses (requiring management Measures). We contend that this approach is needed for the sustainable development and use of this ecosystem and its biodiversity protection. This also indicates the importance of a holistic and systems approach, which is necessary, valid and valuable for sandy beaches worldwide.

Litter surveys were carried out in August and September 2020 to determine the contribution of Sabaki River and estuary in modifying the quantities of litter entering the oceans. The river discharged 0.035 items m⁻³s ⁻¹ translating to an estimated annual litter flux of between 6,622,560 and 614,952,000. The surveys in the estuary revealed that plastics contributed 90.8% of the total litter. Wet and dry zones had mean litter accumulation rates of 2.7 ± 1.1 and 4.4 ± 3.5 items m⁻¹ day⁻¹ respectively. 69.8% and 77.4% of branded litter were of Kenyan origin and food packaging material respectively. The litter turnover was slightly higher in the dry beach zone compared to the wet zone with a Whitakker Beta diversity of 0.36 and 0.33 respectively. Sabaki estuary acted as a sink for litter during flooding (through burial) and as a source (through exposure of buried litter due to wind and rain action).

Industrial and commercial port activities are widely recognized worldwide as an important source of pollution to proximal estuaries. In this study, we analysed geochemical and sedimentological parameters including major and trace elements, organic matter and sediment texture in surface sediments from the estuarine environment of Southampton Water, U.K. Using these data, and multivariate statistical tools [correlation, factor and cluster analysis and pollution indices such as Enrichment Factor (EF), Pollution Load Index (PLI) and the Adverse Effect Index (AEI)], we examine sedimentary trace metal and metalloid contamination, contamination sources, and potential biological impacts of the contamination present. The geochemical data, multivariate statistical analysis and pollution indices indicate that the spatial distribution of trace metals and metalloids is influenced by both sediment composition (and mixing) and anthropogenic activities. Most trace metal and metalloid concentrations are close to local geological background levels, except for Cu, Zn and Pb. The spatial distribution of these elements indicates that the Exxon oil refinery, Southampton port, local marinas and runoff from domestic and industrial activities act effectively as point sources of these elements. Pollution indices calculations highlight a degraded environment as a result of these pollutants, and further work is needed to assess the current impact of trace metals and metalloids on local ecology.

Although banned for years, organochlorine pesticides and PCBs continue to affect aquatic life, dolphins being particularly exposed. The concentrations of 31 PCB congeners, and 15 banned pesticides or metabolites were measured in 5 tissues of 68 striped dolphins stranded in the Northwestern Mediterranean coast in 2010–16. The results were compared to historical data (1988–2009) and, even though there is a slow decreasing trend, the levels in the 2010–2016 samples were still elevated based on common cetacean toxicological thresholds. A transition period in 2007–08, probably caused by a morbillivirus epizootic amplified the stranding, espacially of highly contaminated specimens. From 2010, higher proportions in parent compounds towards metabolites were observed yet again. These changing patterns were likely reflect the exposure of dolphins to the remobilization of pollutants from contaminated soils and sediments, with a prominent role of rivers. This should lead to an even slower decline of these contaminants that could last for decades, requiring new efforts to reduce their dispersal to aquatic ecosystems.

Ingestion of marine debris by ocean sunfishes is not very well documented. As the feeding behaviour of these giants of the seas is very similar to marine turtles, it is expected that the accidental ingestion of plastics could be registered in these species of fish. With this work it is noticed for the first time the presence of a blue plastic fragment, classified by its size as a mesoplastic, in the digestive system of Mola mola (L.) (Molidae) from western Mediterranean Sea.

During the COVID-19 pandemic, disposable surgical masks were generally disinfected and reused due to mask shortages. Herein, the role of disinfected masks as a source of microplastics (MPs) and nanoplastics (NPs) was investigated. The amount of MPs and NPs released from masks disinfected by UV ranged from 1054 ± 106 to 2472 ± 70 and from 2.55 ± 0.22 × 10⁹ to 6.72 ± 0.27 × 10⁹ particles/piece, respectively, comparable to that of the undisinfected masks, and the MPs were changed to small-sized particles. The amount of MPs and NPs released after alcohol and steam treatment were respectively lower and higher than those from undisinfected masks, and MPs were shifted to small-sized particles. The amount of MPs and NPs released in water after autoclaving was lower than for undisinfected masks. In all, the amount of fibers released after disinfection decreased greatly, and certain disinfection processes were found to increase the amount of small-sized NPs released from masks into aqueous environments.

The annually recurring Yellow Sea green tide causes significant economic, social, and ecological impacts in China. Currently, the magnitude of Yellow Sea green tide is usually evaluated according to the snap shot maximum algal coverage area or artificially removed algal biomass. However, this method ignores growth of the alga Ulva prolifera and thus needs improvement. We build a model to predict algal growth in drifting from upstream and the potential muaximum biomass of green tide. The results suggest that the potential maximum biomass is significantly higher than those estimated merely from maximum algal coverage area, particularly for years with extended period of algal loading in the upstream. Our method improves the evaluation of the magnitude of green tide and provides a scientific basis for developing effective countermeasures to reduce the persistent disaster.

There is scarce information on the current importance of oyster beds as fishing grounds in the United Arab Emirates (UAE). This study aims to understand the socio-economic value of oyster bed fisheries through questionnaire-based surveys with fishers. Of 106 Emirati fishers interviewed, 67 % use oyster beds due to the proximity to shore, better catch quality, and species abundance. Oyster bed fisheries are recreational and commercial, with handline and fish traps the most common used gears. They provide food for local consumption and cash income. All respondents noticed a fish abundance and size decrease throughout the last decade. Fishers suggest establishing marine protected areas and updating fishing regulations to improve fishing stock status. During the Covid-19 pandemic, oyster fisheries increased, highlighting the value of these fishing grounds for food availability. These fisheries support the local economy and heritage, and urgently need management to ensure the protection of these often-overlooked habitats.

When encountering adverse environmental conditions, some holothurians can eject their internal organs in a process called evisceration. As global warming intensified, eviscerated and intact sea cucumbers both experience heat stress, but how they performed was uncertain. We constructed 24 metabolomics profiles to reveal the metabolite changes of eviscerated and intact sea cucumbers under normal and high temperature conditions, respectively. Carboxylic acids and fatty acyls were the most abundant metabolic categories in evisceration and heat stress treatments, respectively. Neural transduction was involved in sea cucumber evisceration and stress response, and the commonly enriched pathway was “neuroactive ligand-receptor interaction”. Lipid metabolism in eviscerated sea cucumbers differed from those of intact individuals and was more seriously affected by heat stress. Choline is a key metabolite for revealing the evisceration mechanism. Our results contribute to understanding the mechanisms of evisceration in sea cucumbers, and how sea cucumbers might respond to increasingly warming ocean conditions.