Increasing offshore oil and gas exploration and development in harsh/Arctic environments require more effective offshore produced water management, as these environments are much more sensitive to changes in water quality than more temperate climates. However, the number and scope of studies of offshore produced water management in harsh/Arctic environments are limited. This paper reviews the current state of offshore produced water management, impacts, and policies, as well as the vulnerability, implications and operational challenges in harsh/Arctic environments. The findings show that the primary contaminant(s) of concern are contained in both the dissolved oil and the dispersed oil. The application of emerging technologies that can tackle this issue is significantly limited by the challenges of offshore operations in harsh/Arctic environments. Therefore, there is a need to develop more efficient and suitable management systems since more stringent policies are being implemented due to the increased vulnerability of harsh/Arctic environments.

Several statistical methods are performed in this study to evaluate the effect of emission control measures on particulate matter (PM) concentrations during the 2014 Asia–Pacific Economic Cooperation (APEC) Summit held in Beijing. The concentration of PM2.5 is reduced by 30%, 38% on a year-on-year and month-on-month basis during the APEC emission control period while PM10 reducing by 41% and 26% respectively. Considering from the impacts of the weather circulation types, PM2.5 and PM10 are both reduced by 34%.ANN model is considered to be appropriate with the ability of characterising non-linear phenomena. In this work an ANN model is built to predict the daily averaged PM concentrations. Comparing the observed PM concentrations and the predicted value which are forecasted by ANN model on condition that no emission control measures were carried out during the APEC, the reductions for PM2.5 and PM10 are 24%, 28% respectively. All these results suggest that strict emission control measures push down the pollution level effectively, and more observed data with long time could improve the accuracy of evaluation results. More stringent controls of regional emissions should be lasted for the continuous improvements of air quality in Beijing-Tianjin-Hebei region.

The occurrence and distribution of nine selected compounds were investigated in surface water, suspended particulate matter (SPM), and sediment in Taihu Lake and its tributaries. With the exception of 4-Butylphenol, all compounds were detected in at least two phases, and nonylphenol (NP) and 4-tert-Octylphenol (4-OP) were the predominant alkylphenols (APs) in the lake. A significant correlation was observed between NP and 4-OP, indicating that they may share the same source. Moreover, surface water phase was the dominant sink of Bisphenol A (BPA) in the aquatic environment. The concentrations of BPA between the surface water and SPM phases were closely related to each other. In addition, Tetrabromobisphenol A (TBBPA) exhibited relatively higher concentrations and detection frequencies in the SPM. Risk assessment revealed greater risk associated with the surface water than the sediment, indicating that the discharge of industrial wastewater and domestic sewage poses a serious threat to aquatic ecosystems.

The management of dredged marine sediment is an issue for many harbours, particularly when contaminant concentrations prevent disposal at sea. The stabilisation/solidification of the sediments with hydraulic binders for a use in road subgrade layer is a potential alternative solution. However, the environmental acceptability is not yet fully established. This paper presents the results of a case study to comprehensively determine the stabilisation of As, Cd, Cr, Cu, Ni, Pb and Zn. After demonstrating that stabilisation/solidification affects the microstructure of the sediment, a mobility study is realised (single, sequential and kinetic extractions). According to the regulatory/technical guidelines the studied elements do not pose a risk to the environment. However, results from more complex mobility studies reveal that stabilisation in the short term is only effective for Ni while other elements are mobilised after treatment by at least one type of extraction. Stabilisation in the long term is not universally effective.

Magdalena Bay is an important habitat for marine organisms, some of which have been the subject of metal bioaccumulation studies. Cannery waste is discharged into the bay providing a plausible source of contamination but this study finds that some metals occur geogenically. Bay sediments and rocks (n=59) were analyzed for total metals and clustered (HCA) into two distinct groups with PCA indicating concentrations of Cr, Cu, Mn, and Ni influenced samples near ophiolite outcrops, which reported some metal concentrations exceeding averages in the crust by an order of magnitude (up to 4450ppm Cr and 1269ppm Ni). Metals at the cannery are rarely elevated above crustal averages except Zn (max. 160ppm), however, acid-extracted Zn was below recommended sediment quality guidelines in contrast to 80% of ophiolitic samples reporting Ni extractability exceeding such guidelines. This study raises awareness of geogenic metals when considering sources of contamination in marine environments.

Once non-biodegradable, microplastics remain on the environment absorbing toxic hydrophobic compounds making them a risk to biodiversity when ingested or filtered by organisms and entering in the food chain. To evaluate the potential of the contamination by microplastics in mussels cultivated in Jurujuba Cove, Niterói, RJ, waters of three stations were collected during a rain and dry seasons using a plankton net and later filtered. Microplastics were quantified and characterized morphologically and chemically. The results showed a high concentration of microplastics in both seasons with diversity of colors, types and sizes. Synthetic polymers were present in all samples. The presence of microplastics was probably due to a high and constant load of effluent that this area receives and to the mussel farming activity that use many plastic materials. Areas with high concentrations of microplastics could not be used for mussel cultivation due to the risk of contamination to consumers.

Seasonal dynamics of coral reef fish assemblages were assessed along a gradient of potential anthropogenic disturbance in the Northern Persian Gulf. Overall, the attributes of coral reef fish assemblages showed seasonality at two different levels: seasonal changes irrespective of the magnitude of disturbance level (e.g. species richness), and seasonal changes in response to disturbance level (e.g. total abundance and assemblage composition). The examined parameters mostly belonged to the second group, but the interpretation of the relationship between patterns of seasonal changes and the disturbance level was not straightforward. The abundance of carnivorous fishes did not vary among seasons. SIMPER identified the family Nemipteridae as the major contributor to the observed spatiotemporal variations in the composition of coral reef fish assemblages in the study area.

Levels, sources, and potential ecological risks of polycyclic aromatic hydrocarbons (PAHs) in surface seawater and sediments from the northern Liaodong Bay of China were seasonally investigated. Total concentrations of 16 PAHs varied from 145.96ng/L to 896.58ng/L in seawater, and from 191.99ng/g to 624.44ng/g in sediments. PAH concentrations in seawater differed significantly, whereas those in sediments exhibited a relatively stable pattern across seasons. PAHs with low molecular weight were predominant in seawater, but PAHs with high molecular weight were abundant in sediments. Crop straw and coal combustion were the main PAH pollution sources. The current levels of PAHs in the northern Liaodong Bay are relatively moderate compared with those in other bays and estuaries. Sediment from all sampling sites is characterized by low to medium ecotoxicological risk. No highly negative toxic effect could occur on the organisms and ecosystems in the northern Liaodong Bay.

Sediments from Shantou Bay, China, were analyzed for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) for the first time. The concentrations of PCBs and OCPs were 0.54–55.5ngg−1 and 2.19–16.9ngg−1 (dry weight), respectively. Source identification showed that tri-CBs and penta-CBs were manufactured and used in the last century, while usage of antifouling paint might still serve as a significant source of sediment DDT. Concentrations of PCBs and HCHs significantly (p<0.05) increased after wet season, suggesting that atmospheric deposition and surface runoff played an important role in distribution of historical pollutants. Additionally, the adverse biological effects could occasionally occur for DDT in sediments. The mass inventories were preliminarily calculated for PCBs (90.1ngcm−2 and 0.09tons) and OCPs (61.8ngcm−2 and 0.062tons) in Shantou Bay, while as part of the “reservoir” of organochlorine compounds to the global ocean, its role cannot be neglected.

This study examined the variation of macrofaunal communities in sea grass beds along a pollution gradient in Bolinao, northwestern Philippines. We established four stations and compared the diversity and abundance of macrofauna between them. The Shannon diversity index in the least polluted station was more than twice higher than that in the most polluted one. Abundance was more than thrice higher in the most polluted station. The species composition generally varied, with community difference explained largely by the predominance of the filter-feeding bivalve Gafrarium pectinatum and polychaete Capitella capitata. Species heterogeneity was reduced along the pollution gradient by approximately 19% from the least polluted to the most polluted station. This reduction indicates biodiversity alteration, which has a significant impact on ecosystem functioning. Aspects of species heterogeneity should be considered in environmental impact assessments and the management of coastal areas encountered with anthropogenic disturbances.