This study reports the occurrence and distribution of synthetic musks (SMs) and organic UV filters (UVFs) in sediment samples collected in 8 riverine runoffs from the Pearl River and Pearl River estuary (PRE). Here, 6 of the 8 target compounds were detected in all sediments with concentrations ranging from 0.35ngg−1 to 456ngg−1. Higher concentrations of SMs and UVFs were evident in the eastern outlets compared to the western suggesting greater input of these contaminants from the Pearl River Delta (PRD) region. All the compounds showed a decreasing trend toward the seaward side which confirming that riverine runoff was the most important source of SMs and UVFs to the coastal environment. Notably, high levels of SMs and UVFs were detected in two fishing harbors in the PRE area. In comparison to UVFs, the SM compounds exhibited a significant correlation with TOC content in the sediments.

The effects of gold (ionic form and nanoparticles — AuNPs) and pharmaceuticals (carbamazepine and fluoxetine) on enzymes involved in neurotransmission (acetylcholinesterase — AChE) and biotransformation (glutathione S-transferases — GST) were assessed by their incubation with Mytilus galloprovincialis' hemolymph and subcellular fraction of gills, respectively. AuNPs did not alter enzymatic activities unlike ionic gold that inhibited AChE and GST activities at 2.5 and 0.42mg·L−1, respectively. Carbamazepine inhibited AChE activity at 500mg·L−1 and fluoxetine at 1000mg·L−1. GST was inhibited by carbamazepine at 250mg·L−1 and by fluoxetine at 125mg·L−1. Increased AChE activity was found in simultaneous exposures to fluoxetine and bovine serum albumin coated AuNPs (BSA-AuNPs). Concerning GST, in the simultaneous exposures, AuNPs revealed protective effects against carbamazepine (citrate and polyvinylpyrrolidone coated) and fluoxetine (citrate and BSA coated) induced inhibition. However, BSA-AuNPs increased the inhibition caused by carbamazepine. AuNPs demonstrated ability to interfere with other chemicals toxicity justifying further studies.

Microplastic pollution (particles <5mm) is a widespread marine threat and a trigger for biological effects, especially if ingested. The mussel Perna perna, an important food resource, was used as bioindicator to investigate the presence of microplastic pollution on Santos estuary, the most urbanized area of the coast of São Paulo State, Brazil. A simple and rapid assessment showed that 75% of sampled mussels had ingested microplastics, an issue of human and environmental concern. All sampling points had contaminated mussels and this contamination had no clear pattern of distribution along the estuary. This was the first time that microplastic bioavailability was assessed in nature for the southern hemisphere and that wild P. perna was found contaminated with this pollutant. This is an important issue that should be better assessed due to an increase in seafood consumption and culture in Brazil and worldwide.

We investigated the nine heavy metal contents in the sediments and macrobenthos of the Yellow River Delta Wetlands using three experimental areas that received freshwater releases and one reference area that did not. Heavy metal contents, the single-factor contamination index (SFCI), the metal contamination index (MCI), and the biota-sediment accumulation factor (BSAF) were used to evaluate the potential ecological risk and bioaccumulation. We found that As exceeded the national standard value by more than 50%, and that the ranges of SFCI for each metal were generally larger in autumn than in spring. MCI showed no clear pattern, but the BSAF results suggest that Cd bioaccumulates from sediments to macrobenthos. Pollution-resistant species such as Corophium sinense, Chironomus sp., and Einfeldia sp. became dominant in the areas receiving freshwater releases, and provide direct evidence of ecological risk in the wetlands. Our results provide preliminary information to guide managers for ecological risk assessments.

We examined the variation of pelagic larval durations (PLDs) among three damselfishes, Dascyllus aruanus, D. marginatus, and D. trimaculatus, which live under the influence of an environmental gradient in the Red Sea. PLDs were significantly correlated with latitude, sea surface temperature (SST), and primary production (CHLA; chlorophyll a concentrations). We find a consistent decrease in PLDs with increasing SST and primary production (CHLA) towards the southern Red Sea among all species. This trend is likely related to higher food availability and increased metabolic rates in that region. We suggest that food availability is a potentially stronger driver of variation in PLD than temperature, especially in highly oligotrophic regions. Additionally, variations in PLDs were particularly high among specimens of D. marginatus, suggesting a stronger response to local environmental differences for endemic species. We also report the first average PLD for this species over a broad geographic range (19.82±2.92days).

The effects of linear alpha olefin (LAO) nonaqueous drilling fluid on benthic macrofauna were assessed over a six year period at a southern Caspian Sea petroleum exploration site. A wide-ranging, pre-drilling survey identified a relatively diverse shelf-depth macrofauna numerically dominated by amphipods, cumaceans, and gastropods that transitioned to a less diverse assemblage dominated by hypoxia-tolerant annelid worms and motile ostracods with increasing depth. After drilling, a similar transition in macrofauna assemblage was observed with increasing concentration of LAO proximate to the shelf-depth well site. Post-drilling results were consistent with a hypothesis of hypoxia from microbial degradation of LAO, supported by the presence of bacterial mats and lack of oxygen penetration in surface sediment. Chemical and biological recoveries at ≥200m distance from the well site were evident 33months after drilling ceased. Our findings show the importance of monitoring recovery over time and understanding macrofauna community structure prior to drilling.

Extended use of GC–FID and GC–MS in oil spill fingerprinting and matching is significantly important for oil classification from the oil spill sources collected from various areas of Peninsular Malaysia and Sabah (East Malaysia). Oil spill fingerprinting from GC–FID and GC–MS coupled with chemometric techniques (discriminant analysis and principal component analysis) is used as a diagnostic tool to classify the types of oil polluting the water. Clustering and discrimination of oil spill compounds in the water from the actual site of oil spill events are divided into four groups viz. diesel, Heavy Fuel Oil (HFO), Mixture Oil containing Light Fuel Oil (MOLFO) and Waste Oil (WO) according to the similarity of their intrinsic chemical properties. Principal component analysis (PCA) demonstrates that diesel, HFO, MOLFO and WO are types of oil or oil products from complex oil mixtures with a total variance of 85.34% and are identified with various anthropogenic activities related to either intentional releasing of oil or accidental discharge of oil into the environment. Our results show that the use of chemometric techniques is significant in providing independent validation for classifying the types of spilled oil in the investigation of oil spill pollution in Malaysia. This, in consequence would result in cost and time saving in identification of the oil spill sources.

In this study, seawater quality measurements, including salinity, sea surface temperature (SST), chlorophyll-a (Chl-a), Secchi disk depth (SDD), pH, and dissolved oxygen (DO), were made from June 2013 to November 2014 at 52 stations in the southeastern Arabian Gulf. Significant variability was noticed for all collected parameters. Salinity showed a decreasing trend, and Chl-a, DO, pH, and SDD demonstrated increasing trends from shallow onshore stations to deep offshore ones, which could be attributed to variations of ocean circulation and meteorological conditions from onshore to offshore waters, and the likely effects of desalination plants along the coast. Salinity and temperature were high in summer and low in winter while Chl-a, SDD, pH, and DO indicated an opposite trend. The CTD profiles showed vertically well-mixed structures. Qualitative analysis of phytoplankton showed a high diversity of species without anomalous species found except in Ras Al Khaimah stations where diatoms were the dominating ones.

The spatial variation, possible sources and ecological risk of polychlorinated biphenyls (PCBs) in the sediment from the Songhua River, China were investigated and evaluated in this paper. The total concentration of PCBs ranged from 0.59 to 12.38ng/gdw, with a mean value of 3.82ng/gdw. The seven indicators of PCB concentrations are significantly correlated with the total PCB concentrations (R=0.950, p=0.000). The temporal trend of PCBs in sediments showed that the total PCBs in the Songhua River have decreased since 2008. Point source pollution, discharge of historical usage and industrial sewage, and emissions of unintentionally produced PCBs were the predominant sources in sediment. A risk assessment indicated that most of the sampling sites in the sediment were at low potential ecological risk. The apparent decrease of PCBs in the sediment appeared after the China National Coordination Group for Implementation of the Stockholm Convention was established. A conceptual reverse management framework for PCBs and other organic pollutants was established in this study.

Secondary pollutant impacts from emissions of single sources may need to be assessed to satisfy a variety of regulatory requirements including the Clean Air Act New Source Review and Prevention of Significant Deterioration programs and the National Environmental Policy Act. In this work, single source impacts on O3 and secondary PM2.5 are estimated with annual 2011 photochemical grid model simulations where new hypothetical sources are added to the central and eastern United States with varying precursor emission rates and emission release heights. Impacts from these hypothetical sources are tracked with photochemical grid model source apportionment. Single source impacts on downwind 8-hr maximum O3 tend to increase as emissions of NOX or VOC increase. Downwind impacts on PM2.5 sulfate and nitrate also tend to increase as emissions of SO2 and NOX increase. For all secondary pollutants, impacts from these hypothetical sources tend to decrease as distance from the source increases. However, peak impacts on O3 and secondary PM2.5 are not at the facility fence-line but typically within 50–100 km depending on the emissions rate, precursor pollutant, and emissions release point. Downwind impacts are not uniform directionally from these sources due to varying downwind availability of chemical reactants and prevailing meteorology. Peak impacts for O3 (∼15 ppb) and PM2.5 sulfate (∼8 μg/m3) were within 50 km of these hypothetical sources and peak impacts for PM2.5 nitrate (∼1 μg/m3) were within 125 km. The daily maximum 8-hr O3 and maximum daily average PM2.5 sulfate and nitrate ion impacts for the new hypothetical sources modeled here are generally consistent with those reported in literature. Additional assessments of single source impacts on secondary pollutants are still needed to provide a more comprehensive assessment of different source types and source environments.