Pyrethroids are increasingly receiving attention as aqueous micropollutants, but their presence has been reported only in a few small coastal areas. In this study, we investigated the distribution, sources, and risks of nine pyrethroids in large marine zones. The 40 seawater samples were collected from the South Yellow Sea (SYS) and East China Sea (ECS) in China, during the spring of 2020, using a high-volume, solid-phase extraction method. The total pyrethroid concentrations ranged from 0.72 to 1.82 ng L⁻¹ in the SYS and from 0.02 to 11.0 ng L⁻¹ in the ECS. We used cluster analysis to classify pollutant sources into five categories, and discussed the influence of sources on the transport and distribution of pyrethroids in each group. Ecological risk assessment indicated that pyrethroids pose a high risk to crustaceans and a negligible risk to others. These results are important for understanding the behavior of pyrethroids in marine environments.

Historical ⁹⁰Sr activity in seawater was established in the China seas from 1963 to 2018. Based on the exponential decrease in ⁹⁰Sr activity in seawater, the effective half-life (EHL) of ⁹⁰Sr was quantified to be 11.5 ± 1.6 a, 16.5 ± 2.4 a, 27.2 ± 6.2 a, and 26.7 ± 4.3 a in the Bohai Sea, Yellow Sea, East China Sea, and South China Sea, respectively. We found contrasting patterns in the EHL of ⁹⁰Sr and ¹³⁷Cs in the marginal seas and open oceans that were closely related to the subtly different pathways of ⁹⁰Sr and ¹³⁷Cs in marine environment. Additionally, we demonstrated that Fukushima-derived ⁹⁰Sr (<0.01 Bq/m³) would be difficult to identify in the China seas. Our study not only provided the key parameter of the EHL in marine models for predicting the ⁹⁰Sr activity in the China seas in the post-Fukushima era but also enhanced our understanding of ⁹⁰Sr behavior and its fate in marine environments.

Crassostrea virginica was exposed to different light crude oil levels to assess the effect on transcriptomic response and metabolic rate. The exposure time was 21 days, and levels of 100 and 200 μg/L were used, including a control. The most significant difference among treatments was the overexpression of several genes associated with energy production, reactive oxygen species (ROS) regulation, immune system response, and inflammatory response. Also, a hydrocarbon concentration-related pattern was identified in ROS regulation, with a gene expression ratio near 1.8:1 between 200 and 100 μg/L treatments. Statistical analysis showed no interaction effect for metabolic rate; however, significant differences were found for oil concentration and time factors, with a higher oxygen consumption at 200 μg/L. Our findings provide novel information about the metabolic response of C. virginica during hydrocarbons exposure. In addition, our results point out which biological processes should be investigated as targets for searching bioindicators.

This paper presents a tightly coupled experimental and kinetic approach for efficient remediation of oil spill from contaminated marine intertidal zone surface through a methodical strategy that deals with biosurfactant mediated washing strategy. The study deals with production, optimization and characterization of lipopeptide biosurfactant from Bacillus subtilis T1 and its application in remediation of oil contaminants from mimic model system of various marine intertidal zone i.e. woodland-Group1, saltmarsh-Group2, mangrove-Group3 and mudflats-Group4. Results demonstrates enhanced washing performance with oil desorption rate of 35 % in Group 4, 17.22 %, 15.6 % and 11 % in Group 3, 2 and 1 along with bio surfactant recovery rate of 41 %, 48.7 %, 51.71 % and 50.3 % respectively. Further, the washing strategy was efficient in soil detoxification with highest rate in Group 4. The kinetic validation depicts good match among experimental data and Lagergren pseudo second order data.

Excessive discharge of N and P pollutants results in deterioration of marine environment quality and reduction of sustainability and safety of marine ecology. Spatiotemporal variations characteristics and sources of N and P pollutants were determined based on the long-term monitoring data in Liaodong Bay. Results indicated that an evident spatiotemporal variation was investigated for nutrients. The highest concentrations of NH₃-N, NO₂-N, NO₃-N and PO₄-P were in spring (25.32 μg/L), summer (20.67 μg/L) and autumn (222.07 μg/L, 11.08 μg/L), respectively. The hot-spots of pollutants were mainly concentrated in estuarine and aquaculture areas. The hot spot of PO₄-P gradually extended to the middle of Liaodong Bay in autumn. In addition, pollution sources in each marine functional zone were different, the main pollution source was aquaculture wastewater, river input, domestic sewage. This study provided reasonable suggestions for effectively reducing N and P pollution in Liaodong Bay, and elsewhere.

The ‘taxonomic sufficiency’ (TS) approach has been applied to algae, protists, invertebrates, and vertebrates, generally by aggregating species-level abundance data to a higher taxonomic level, where genus-level data are often highly correlated with species-level data and are a valid proxy level. The TS approach offers the possibility of a comparison of data from different geographical areas and highlights the effects of contaminants. The TS approach is stable in the face of different researchers and in the comparison of long-term biological survey data. The effectiveness of the TS approach may increase with increasing environmental gradients or spatial area. The TS approach should be avoided when the spatial area is small and small differences in species-level data are considered important, so as not to cancel out the distribution patterns specific to the local environment of the biological taxa.

Titanium (Ti) is considered a contaminant of emerging interest, as it displays toxic potential and has been increasingly employed in everyday products, pharmaceuticals, and food additives, mainly in nanoparticle form. However, several knowledge gaps are still noted, especially concerning its dynamics in the water. In this context, this study aimed to quantify total Ti concentrations in highly consumed swimming crabs, squid, and shrimp from an important estuary located in southeastern Brazil. Ti concentrations were higher than those reported in most studies carried out worldwide. Animal length and weight, as well as, depth, transparency, dissolved oxygen, and salinity, significantly influence Ti concentrations in the animals. Human health risks were also noted after calculating a simulated exposure to titanium dioxide, especially considering the uncertainties regarding the effects of this element and the absence of regulatory limits.

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.