In order to study the pollution levels and spatiotemporal trend of Dichlorodiphenyltrichloroethanes (DDTs) in the Southern Yellow Sea (SYS), thirty-two surface sediment samples and a sediment core have been analyzed, and our results have been compared with previous reports. DDTs contents in our samples ranged from below detection limit to 5.1ng/gdry weight (d.w.), which presented lower ecological risks in the SYS. Surface sediment results show a seaward increasing trend with high values in the northern region of the central basin of the SYS. Our reconstructed core record and historical data from previous reports reveal an increasing trend from 1905 to 1955 but a decline trend since 1985 for DDTs, which is consistent of the production, usage and banning of DDTs in China. The source identification, based on (DDE+DDD)/DDTs, suggested that aged DDTs were the major contributor, though there were some inputs of fresh DDTs from the usage of 1,1-bis(p-Chlorophenyl)-2,2,2-trichloroethanol (dicofol).

The role of soil carbon (C) in coastal wetlands as a net sink is related to the relative abundance of autochthonous versus allochthonous C. We aimed to investigate soil C sources and the pathways by which mangrove vegetation enhances soil C accumulation. We sampled soil to 1 m depth in seven oceanic mangrove forests and an adjacent un-vegetated mudflat at Dongzhai Bay, China. Stable C isotope technique was used to separate autochthonous and allochthonous C sources. Autochthonous C accounted for 27–97% of soil C stock in the top meter. Soil C density was 1.1–3.6 times higher in mangroves than in the mudflat. Among the increased soil C in mangroves relative to mudflat, autochthonous C accounted for 65–100% of the increments. The results suggest that mangrove vegetation enhances soil C storage primarily through in situ inputs, therefore the substantial soil C stocks commonly found in mangroves play an important role in sequestering atmospheric CO2.

Blooms of Ostreopsis cf. ovata, causing health incidence and mass human intoxications in the Mediterranean, gained special attention over the past decades. To study the potential effects of temperature and nutrient enrichment on this benthic dinoflagellate and other associated microalgae in situ, a multifactorial experiment was set up along a temperature gradient of a heat pump system in Monaco. Microalgae were quantified in experimental units, in the natural biofilm and in the water column. No significant interaction was observed between temperature and nutrients. A species- and bloom phase-dependent effect of the increased temperature was recorded, while the nutrient enrichment had a significant effect only at the end of the experiment (when cell abundances were low). Temperature effects were also visible in the biofilm and the surrounding water. The observed assemblages were mainly driven by changes in abundances of Ostreopsis cf. ovata and Actinocyclus sp., affected in different ways.

Here we report on the distribution of microplastic contamination in two developed estuaries in the Southeastern United States. Average concentration in intertidal sediments of Charleston Harbor and Winyah Bay, both located in South Carolina, U.S.A., was 413.8 ± 76.7 and 221.0 ± 25.6 particles/m2, respectively. Average concentration in the sea surface microlayer of Charleston Harbor and Winyah Bay was 6.6 ± 1.3 and 30.8 ± 12.1 particles/L, respectively. Concentration in intertidal sediments of the two estuaries was not significantly different (p = 0.58), however, Winyah Bay contained significantly more microplastics in the sea surface microlayer (p = 0.02). While microplastic concentration in these estuaries was comparable to that reported for other estuaries worldwide, Charleston Harbor contained a high abundance of black microplastic fragments believed to be tire wear particles. Our research is the first to survey microplastic contamination in Southeastern U.S. estuaries and to provide insight on the nature and extent of contamination in these habitats.

In order to investigate the sources of plutonium in seawaters of Liaodong Bay and Bohai Strait, China, surface seawater samples were collected and analyzed for 239+240Pu and 137Cs by radiochemical separation combined with ICP-MS and γ-spectrometry, respectively. A large variation of 239+240Pu activities was observed, ranging from 1.993 to 29.677 mBq/m3 in the Liaodong Bay and from 0.932 to 10.183 mBq/m3 in the Bohai Strait. 137Cs activities showed little variation between the investigated locations, which was attributed to the different behavior characteristics of 239+240Pu and 137Cs in seawaters. The 240Pu/239Pu atom ratios showed a significant variation between the Liaodong Bay (0.185) and Bohai Strait (0.225), indicating that Pu derived from the Pacific Proving Grounds might have been transported to the Bohai Strait but not yet to the Liaodong Bay, which could further provide valuable reference for evaluating the seawater exchange cycle between the Bohai Sea and Yellow Sea.

Lagoon Burullus is located in the North West quadrant of the Nile Delta. It receives drainage water through several drains around the lagoon. Understanding the mobility and bioavailability of zinc metal in bottom sediments of Lagoon Burullus is essential for the design of remediation processes and the institution of environmental recommendation for zinc pollution.Single extractions used to fractionate zinc into five fractions. The chemical analyses preceded using atomic absorption spectrometry after using the digestion technique. Zinc concentrates in the residual fraction (167.5μg/g) followed by the organic (14.6μg/g), exchangeable (3.2μg/g), carbonate (2.4μg/g) and then the Fe-Mn hydroxides (1μg/g) fractions. The average content of zinc (189μg/g) is about three fold the average earth's crust.Ecological pollution index show that the metal has a low-risk assessment to surrounding ecosystem. The anthropogenic activities considered as the main source of pollution.

Present work aims to document the distribution and metal contamination in the coastal sediments of the Dammam Al-Jubail area, Saudi Arabian Gulf. Twenty-six samples were collected for Al, V, Cr, Mn, Cu, Zn, Cd, Pb, Hg, Sr, As, Fe, Co and Ni analysis. Results of enrichment factor indicated that Sr, Cd, Cu, Hg, V, As, Ni, Cr and Zn gave enrichment factors higher than 2 (98.87, 40.28, 33.20, 27.87, 26.11, 14.10, 6.15, 3.72 and 2.62 respectively) implying anthropogenic sources, while Pb, Mn and Al have very low background level (1.37, 0.71, 0.124 respectively), probably originated from natural sources. Average concentrations of Sr, V, Hg, Cd and As were mostly higher than those from the background shale and the earth crust, the Caspian Sea, the Mediterranean Sea, the sediment quality guidelines, the Red Sea, the Gulf of Aqaba and the Gulf of Oman. The higher levels of the studied metals are mostly related samples with high Al and TOM content, as well as the visible anthropogenic pollutants along the studied coastline. The most recorded anthropogenic pollutants were sewage effluent, landfilling due to coastal infrastructure development, oil spills, petrochemical industries and desalination plants in Al-Jubail industrial city.

The Bohai Sea is characterized as a semi-closed sea with limited water exchange ability, which has been regarded as one of the most contaminated regions in China and has attracted public attention over the past decades. In recent years, the rapid industrialization and urbanization around the coastal region has resulted in a severe pollution pressure in the Bohai Sea. Although efforts from official government and scientific experts have been made to protect and restore the marine ecosystem, satisfactory achievements were not gained. Moreover, partial coastal areas in the Bohai Sea seemingly remain heavily polluted. In this study, we focused on five coastal regions around the Bohai Sea to study the spatial distribution pattern of trace elements in the sediments and their ecological risk. A total of 108 sediment samples were analyzed to determine the contamination degree of trace elements (Cu, Cd, As, Pb, Zn, Cr, and Hg). Contamination factor (CF), pollution load index (PLI), geoaccumulation index (Igeo), and potential ecological risk index (PERI) were utilized to assess the pollution extent of these metals. Spatial distribution patterns revealed that the sedimentary environments of coastal Bohai were in good condition, except Jinzhou Bay, according to the Marine Sediment Quality of China. The concentrations of Hg and Cd were considerably higher than the average upper crust value and presented high potential ecological risk and considerable potential ecological risk, respectively. The overall environment quality of the coastal Bohai Sea does not seem to pose an extremely serious threat in terms of metal pollution. Thus, the government should continue implementing pollution control programs in the Bohai Sea.

Diuron is an alternative biocide suggested to replace organotin in formulating antifouling paints to be applied on water-going vessels hull. However, it is potentially harmful to various non-targeted marine organisms due to its toxic properties. Present study aimed to isolate, screen and identify the potential of Diuron-degrading bacteria collected from the marine sediments of Port Klang, Malaysia. Preliminary screening was conducted by exposing isolated bacteria to 430ng/L (background level), followed by 600ng/L and 1000ng/L of Diuron concentrations. Nine bacteria colonies survived the exposure of the above concentrations. However, only two strains can tolerate to survive up to 1000μg/L, which were then characterised and identified using phenotypic tests and the standard 16S rRNA molecular identification. The strains were identified as Comamonas jiangduensis SZZ 10 and Bacillus aerius SZZ 19 (GenBank accession numbers: KU942479 and KU942480, respectively). Both strains have the potential of Diuron biodegradation for future use.