The concentrations and distribution of monoaromatic hydrocarbons (benzene, toluene, ethyl benzene and the sum of m-, p- and o-, xylenes) were determined in the sediments of coastal lagoons of the Gulf of Saros, using a static headspace GC–MS. The total concentrations of BTEX compounds ranged from 368.5 to below detection limit 0.6μgkg−1 dw, with a mean value of 61.5μgkg−1 dw. The light aromatic fraction of m-, p-xylene was the most abundant compound (57.1% in average), and followed by toluene (38.1%)>ethylbenzene (4.1%)>o-xylene (2.5%)>benzene (1.1%). The factor analysis indicated that the levels and distribution of BTEX compounds depend on the type of contaminant source (mobile/point), absorbance of compounds in sediment, and mobility of benzene compound and degradation processes. Point sources are mainly related to agricultural facilities and port activities while the dispersion of compounds are related with their solubility, volatility and effect of sea/saline waters on lagoons.

Sharks, rays, skates and chimaeras play an important role as predators in the ecosystems. These species could serve as potential sentinels for the presence of xenobiotics in marine ecosystems. In this study, liver carboxylesterase (CbE) activity was determined for 20 species of chondrichthyans. Carboxylesterase activity, a known esterase involved in the metabolism of pesticides, lipids and certain drugs, was measured using two substrates: 4-nitrophenyl acetate (pNPA) and α-naphthyl acetate (αNA). Rajiformes (rays and skates) showed higher CbE activity than sharks, and the order Chimaeriformes showed the lowest values. In vitro sensitivity to CbE inhibitors was assessed in the shark Scyliorhinus canicula. The substrate αNA was found to be the most adequate as it displayed the highest activity and was more sensitive to the organophosphate dichlorvos in the liver (IC50=2.37μM) and plasma (IC50=0.051μM). The high interspecific variation of CbE activity and its sensitivity to inhibition by fenofibrate suggest that this enzyme could contribute to species-specific differences in drug detoxification.

Eight new seagrass beds were discovered along the coastline of Hainan Island in South China Sea with an area of 203.64ha. The leaf N content of all seagrasses was above the median value, indicative of N limitation, with their C:N ratio recorded significantly lower than the limiting criteria. This suggested that N is not limiting but in replete status. Further, the lower C content observed in the seagrass leaves was accompanied by higher nutrient concentration. The mean seagrass biomass C was 0.23±0.16MgCha−1, while the average sediment organic carbon (SOC) stock was 7.02±3.57MgCha−1. The entire SOC stock of the newly discovered seagrass beds was 1306.45 Mg C, and the overall SOC stock of seagrass bed at Hainan Island was 40858.5 Mg C. These seagrass beds are under constant threats from sea reclamation, nutrient input, aquaculture activities for oyster and snail farming, and fishing activities.

The environmental risk analysis of aquatic systems includes the evaluation of the likelihood that adverse ecological effects may occur as a result of exposure to one or more stressors. In harbor areas, pollution is provided by a complex mixture of substances with different levels of toxicity, persistence and bioaccumulation, which complicates the hazards characterization and their multiple effects. A study of the relationship between the environmental impact and the environmental risk assessment at a specific isolated oil handling facility was undertaken. The environmental risk of the oil handling facility, considering the consequences of specific pollutants, was estimated and the associated environmental impact was quantified based on a ‘weights of evidence’ approach. The contamination quantified at the potentially affected area around the monobuoy of Tarragona has proved to be related with environmental risk estimations but the lines of evidence obtained do not allow us to assert that the activity developed at this facility has an associated environmental impact.

Heavy metals are a hazard to marine fauna and human health. In this study we assess stable isotopes and metal content in Prionace glauca and Isurus oxyrinchus and analyse these results within and among other species and across regions and geographical areas. Also, we evaluate their suitability, together with Raja clavata and Galeorhinus galeus, as Mid-Atlantic bioindicators. Prionace glauca and I. oxyrinchus shared the same trophic level in a pelagic food web and did not present significant differences between genders or metals, except for As. Arsenic and Hg accumulated while Cd and Pb were not detected. One I. oxyrinchus presented Hg values above regulatory limits. A high Hg exposure was associated with I. oxyrinchus since its maximum weekly intake was exceeded. Elasmobranchs can be used as metal sentinels, each presenting different key features which defines a good marine bioindicator, allowing long-term monitoring at different temporal and spatial scales.

As part of an investigation of the effects of water quality from dredging/natural resuspension on reefs, the effects of suspended sediment concentrations (SSCs) (0, 30, 100mgL−1) and light (~0, 1.1, 8.6molphotonsm−2d−1) were examined alone and in combination, on the corals Acropora millepora, Montipora capricornis and Porites spp. over an extended (28d) period. No effects were observed at any sediment concentrations when applied alone. All corals in the lowest light treatments lost chlorophyll a and discoloured (bleached) after a week. Coral mortality only occurred in the two lowest light treatments and was higher when simultaneously exposed to elevated SSCs. Compared to water quality data collected during large dredging programs and natural resuspension events (and in the absence of sediment deposition as a cause-effect pathway) these data suggest the light reduction associated with turbidity poses a proportionally greater risk than effects of elevated SSCs alone.

In this paper three well known Gaussian dispersion models have been evaluated for a case study of a steel plant using complete and incomplete upper air meteorological data.In developing countries, the availability of surface and upper air meteorological data is limited. AMS/EPA Regulatory Model (AERMOD), Advanced Dispersion Modeling System (ADMS) and Industrial Source Complex Model (ISC3) have been evaluated for both real and estimated upper meteorological data and the results have been compared with field measurements both in the horizontal and vertical directions.The results show significant differences in predicted concentrations when modeling with real (actual) and estimated upper meteorological data. The differences ranged from 100% to 450%. Comparison of model performance suggests that AERMOD and ADMS with real meteorological data produce consistent results in the horizontal direction while ISC3 output over-predicts in general. In AERMOD and ISC3 the predicted concentrations have a similar trend of variation in the vertical direction but in ADMS the concentration variation in the vertical direction exhibited different trends. In general, the ADMS predicted concentrations under-estimated field observations.The paper suggests that upper data must be used for modeling and the default values must be used with care. In absence of upper meteorological data, users could estimate upper meteorological data by different available algorithm rather than only default option of models.

Pb/Ca profiles were measured on ten live collected Ostrea edulis from three sites characterized by different levels of lead content. Intra-shell and inter-shell reproducibility were tested comparing several Pb/Ca profiles measured by LA-ICP-MS within a specimen, and within specimens from the same site. Results indicate that signals recorded are reproducible and mean shell Pb/Ca values are site-dependent. Second order variability is explained either by smoothing effects, biological effects or micro-environmental heterogeneities in lead distribution. Mean Pb contents measured in marine bivalve shells are reviewed here. Ranging from 0 to 50ppm, they show a strong relationship with the environmental level of local lead contamination, and do not appear species-dependent. Our measurements show a linear relationship between mean shell Pb/Ca and surface sediment Pb concentrations, making marine bivalves and particularly O. edulis a potential accurate bio-monitoring tool able to monitor bioavailable lead along European coasts since Mesolithic, with an annual resolution.

Phthalates are an emerging class of environmental pollutants whose distribution and effects in aquatic environments are not well characterized. We analyzed intertidal and emerged beach sediments from the Abruzzo coastline, along the Adriatic Sea, finding significant phthalate concentrations in marine sediments. Phthalate baseline levels in the intertidal environment, marked by substantial interplay of sediment, water and air, were determined. We used statistical rank methods to select representative phthalate compositions, for which we derived risk levels for ingestion, dermal absorption and inhalation. Our study shows that phthalates are a major cause of pollution along the Abruzzo coast, with river transport of sediments a continuous source of replenishment. Phthalate concentrations in two specific sites were determined to be of the same order of magnitude as the safety, remediation-warranting, threshold set by Italian law. Phthalates, heavy metals, PAHs appear to be correlated. We discuss possible intervention and mitigation strategies.

Macrobenthic communities in 2001 and 2012 were compared across the marine environment of Hong Kong based on sediment grab samples collected from 28 stations. CLUSTER analysis showed in both surveys that the stations could be divided into four groups at 20% faunal similarity. However, there were notable changes in the macrobenthic community structure between 2001 and 2012 in three focal areas of pollution control (i.e., Victoria Harbour, Deep Bay and Tolo Harbour). The potential link between macrobenthos and pollution abatement measures, and the contributions of environmental conditions to the differential responsiveness of macrobenthos were explored. Notably, a reduction in nutrient input to the eastern part of Victoria Harbour might have led to recovery of benthic communities therein.