The increase of seawater desalination plants may affect seagrasses as a result of its hypersaline effluents. There are some studies on the salinity tolerance of seagrasses under controlled laboratory conditions, but few have been done in situ. To this end, Cymodocea nodosa shoots were placed during one month at four localities: two close to a brine discharge; and the other two not affected by the discharge, and this experiment was repeated four times. The results obtained showed a decrease in growth and an increased mortality at the localities affected by the brine discharge. An increase was detected in the percentage of horizontal shoots in respect to vertical shoots at the impacted localities. It is probably that not only the average salinity, but also the constant salinity fluctuations and slightly higher temperatures associated with the brine that may have caused physiological stress thus reducing C. nodosa growth and survival.

This study investigated the concentrations and distribution of Perfluoroalkyl and polyfluoroalkyl substances (PFAS) in sediments of 12 rivers from South Bohai coastal watersheds. The highest concentrations of ΣPFAS (31.920ngg−1dw) and PFOA (29.021ngg−1dw) were found in sediments from the Xiaoqing River, which was indicative of local point sources in this region. As for other rivers, concentrations of ΣPFAS ranged from 0.218 to 1.583ngg−1dw were found in the coastal sediments and from 0.167 to 1.953ngg−1dw in the riverine sediments. Predominant PFAS from coastal and riverine areas were PFOA and PFBS, with percentages of 30% and 35%, respectively. Partitioning analysis showed the concentrations of PFNA, PFDA and PFHxS were significantly correlated with organic carbon. The results of a preliminary environmental hazard assessment showed that PFOS posed the highest hazard in the Mi River, while PFOA posed a relative higher hazard in the Xiaoqing River.

Ability of Achromobacter xylosoxidans, a chrysene degrading marine halotolerant bacterium to degrade polycyclic aromatic hydrocarbons (PAHs) using a cost effective laboratory microcosm approach, was investigated. Effect of variables as chrysene, glucose as a co-substrate, Triton X-100 as a non-ionic surfactant and β-cyclodextrin as a PAHs solubilizer was examined on degradation of low molecular weight (LMW) and high molecular weight (HMW) PAHs. A total of eleven PAHs detected from polluted saline soil were found to be degraded. Glucose, in combination with Triton X-100 and β-cyclodextrin resulted in 2.8 and 1.4-fold increase in degradation of LMW PAHs and 7.59 and 2.23-fold increase in degradation of HMW PAHs, respectively. Enhanced biodegradation of total PAHs (TPAHs) by amendments with Triton X-100 and β-cyclodextrin using Achromobacter xylosoxidans can prove to be promising approach for in situ bioremediation of marine sites contaminated with PAHs.

We document the abundance, composition and distribution of microplastics in sub-surface seawaters of the northeastern Pacific Ocean and coastal British Columbia. Samples were acid-digested and plastics were characterized using light microscopy by type (fibres or fragments) and size (<100, 100–500, 500–100 and >1000μm). Microplastics concentrations ranged from 8 to 9200particles/m3; lowest concentrations were in offshore Pacific waters, and increased 6, 12 and 27-fold in west coast Vancouver Island, Strait of Georgia, and Queen Charlotte Sound, respectively. Fibres accounted for ∼75% of particles on average, although nearshore samples had more fibre content than offshore (p<0.05). While elevated microplastic concentrations near urban areas are consistent with land-based sources, the high levels in Queen Charlotte Sound appeared to be the result of oceanographic conditions that trap and concentrate debris. This assessment of microplastics in the NE Pacific is of interest in light of the on-coming debris from the 2011 Tohoku Tsunami.

Five marine fish species were collected from the Natuna Island, South China Sea to investigate the occurrence of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PBDEs, PCBs, and DDTs in marine fish ranged from 2.85 to 7.82, 14.3 to 48.1, and 7.99 to 40.3ng/g lipid weight, respectively. Higher concentrations of PBDEs, PCBs, and DDTs were observed in Snakefish (Trachinocephalus myops), which might be attributed to their different feeding and living habits. PCBs were the predominant POPs in all marine fish, followed by DDTs and PBDEs. BDE 47 and PCB 153 were the predominant congener of PBDEs and PCBs, respectively. Compositional distribution of DDTs indicated the possible presence of fresh input sources around the Natuna Island. The ratios of o,p′-DDT/p,p′-DDT being less than 1 in fish samples suggested that DDT contributions from dicofol seemed considerably low. New input sources of DDT in South China Sea are worth further research.

The continuing degradation of coral reefs has serious consequences for the provision of ecosystem goods and services to local and regional communities. While climate change is considered the most serious risk to coral reefs, agricultural pollution threatens approximately 25% of the total global reef area with further increases in sediment and nutrient fluxes projected over the next 50years. Here, we aim to inform coral reef management using insights learned from management examples that were successful in reducing agricultural pollution to coastal ecosystems. We identify multiple examples reporting reduced fluxes of sediment and nutrients at end-of-river, and associated declines in nutrient concentrations and algal biomass in receiving coastal waters. Based on the insights obtained, we recommend that future protection of coral reef ecosystems demands policy focused on desired ecosystem outcomes, targeted regulatory approaches, up-scaling of watershed management, and long-term maintenance of scientifically robust monitoring programs linked with adaptive management.

Although numerous studies have shown that hypoxia affects cortisol and aldosterone production in vivo, the underlying molecular mechanisms regulating the steroidogenic genes of these steroid hormones are still poorly known. MicroRNAs are post-transcriptional regulators that control diverse biological processes and this study describes the identification and validation of the hypoxia-inducible microRNA, miR-10b, as a negative regulator of the CYP11B1 and CYP11B2 steroidogenic genes in H295R human adrenocortical cells. Using the human TaqMan Low Density miRNA Arrays, we determined the miRNA expression patterns in H295R cells under normoxic and hypoxic conditions, and in cells overexpressing the human HIF-1α. Computer analysis using three in silico algorithms predicted that the hypoxia-inducible miR-10b molecule targets CYP11B1 and CYP11B2 mRNAs. Gene transfection studies of luciferase constructs containing the 3′-untranslated region of CYP11B1 or CYP11B2, combined with miRNA overexpression and knockdown experiments provide compelling evidence that CYP11B1 and CYP11B2 mRNAs are likely targets of miR-10b.

Contaminations in sediments by polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs were investigated at 44 sites in Osaka Bay, Japan. Concentrations of total PAHs and alkylated PAHs were in the range 6.40–7800ng/g dry weights and 13.7–1700ng/g dry weights, respectively. The PAH concentrations tended to be higher along the shoreline in the vicinities of big ports, industrialized areas, and densely populated regions such as the cities of Osaka and Kobe. The major sources appeared to be pyrogenic or both pyrogenic and petrogenic at most of the sites. PAH concentrations were remarkably high at a site near Kobe, where the concentrations of dibenzo(a,h)anthracene and benzo(g,h,i)perylene exceeded the effects-range-medium concentration and eight PAHs were above the corresponding effects-range-low concentrations. Those PAHs may have been derived from the great fire associated with the large earthquake in 1995.

Recently in the Sultanate of Oman, there has been a rapid surge of coastal developments. These developments cause metal contamination, which may affect the habitats and communities at and near the coastal region. As a result, a study was conducted to assess the level of metal contamination and its impact on the marine sediments in the vicinity of the Single Buoy Moorings 3 (SBM3) at Mina Al Fahal in the Sultanate of Oman. Marine subtidal sediment samples were collected from six different stations of the SBM3 for the period ranging from June 2009 to April 2010. These samples were then analyzed for their level and distribution of the heavy metals of cadmium (Cd), copper (Cu), lead (Pb) and vanadium (V). Overall, low concentrations of all four heavy metals were measured from the marine sediments, indicating that the marine at SBM3 is of good quality.

Modeling oil biodegradation is an important step in predicting the long term fate of oil on beaches. Unfortunately, existing models do not account mechanistically for environmental factors, such as pore water nutrient concentration, affecting oil biodegradation, rather in an empirical way. We present herein a numerical model, BIOB, to simulate the biodegradation of insoluble attached hydrocarbon. The model was used to simulate an experimental oil spill on a sand beach. The biodegradation kinetic parameters were estimated by fitting the model to the experimental data of alkanes and aromatics. It was found that parameter values are comparable to their counterparts for the biodegradation of dissolved organic matter. The biodegradation of aromatics was highly affected by the decay of aromatic biomass, probably due to its low growth rate. Numerical simulations revealed that the biodegradation rate increases by 3–4 folds when the nutrient concentration is increased from 0.2 to 2.0mgN/L.