A three dimensional rectangular grid model is applied to resolve the temperature–salinity dynamics of Ruwais, a segment of the UAE coast which is well known as dense water formation zone. The model employs a heat flux module and a turbulence closure scheme that facilitate realistic calculation of temperature–salinity dynamics. A field survey campaign is carried out to support the modeling study, involving measurements of tide, currents, temperature, and salinity. Investigation is done for two meteorologically extreme conditions, i.e. summer and winter. The model study showed that the western flux develops an anticlockwise circulation in the study area. The water industrial discharges elevated the temperature and salinity of the water near the southeastern shoreline. This water mass propagated towards north under the influence of gravity.

Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) were measured in 32 species inhabiting the Yellow Sea to assess their bioaccumulation potentials. The concentrations in these samples were lower than those reported for other countries or locations. Relatively high levels of BDE 209 in biota suggest an ongoing source of deca-BDE technical mixing within the Yellow Sea. The accumulation profiles of PCBs were uniform between species, but the concentrations of OCPs and PBDEs varied widely. Pelagic and benthic food-chain components were separated by their δ13C values. Significant positive correlations between δ15N and PCB 153, PCB 138, p,p′-DDE, oxy-chlordane, and trans-nonachlordane were found only for pelagic consumers, indicating that the pelagic food chain is an important bioaccumulation pathway for selected PCB and OCP compounds. The other compounds did not show any biomagnification through benthic and pelagic food chains, suggesting the lower bioaccumulation potentials of these contaminants.

Tibouchina pulchra (Cham.) Cogn. (Melastomataceae) is a native tree species from the southeast region of Brazil. This early successional species significantly contributes to the characteristic physiognomy and structure of the Atlantic Rain Forest. Saplings were exposed to carbon filtered air (CF), ambient non–filtered air (NF), and ambient non–filtered air +40 ppb ozone (NF+O3), 8 h per day during two months, using open top chambers (OTC). The AOT40 values at the end of the experiment were 48, 910 and 12 895 ppb h–1, respectively for each treatment. After 25 days of exposure, interveinal red stippling appeared in plants in the NF+O3 chamber (AOT40=3 871 ppb h–1). In the NF chamber, symptoms were observed only after 60 days of exposure (AOT40=910 ppb h–1). No changes were observed for total phenolic contents when comparing ozone treatments. However, amounts of tannins and flavonoids were different among treatments. NF+O3 and NF treatment showed enhanced contents of flavonoids, when tannins seem to be reduced after ozone fumigation (p<0.01). Results suggest alteration on phenolic metabolism when saplings are ozone fumigated; those responses, considered T. pulchra, seem to occur before leaf injury appeared, once contents of flavonoids and tannins are also altered by NF treatment (AOT40=910 ppb h–1). This study demonstrates that total phenolic and tannins contents of saplings of T. pulchra also decreased when exposed to ozone. The same alterations were observed for T. pulchra after industrial air pollution, suggesting the reduction on total phenolic and tannins probably is a characteristic response of T. pulchra to presence of any kind of pollutant.

This paper seeks to enhance understanding of the data distribution of ground–level ozone time series by analysing their multifractal spectra. Emphasis is placed on the suitability of the box–counting and moments methods for characterizing scaling properties of ozone concentration, enabling us to describe similarities and differences inferred from the multifractal spectra by analysing various types of monitoring stations (urban, suburban and rural monitoring sites) under identical atmospheric conditions. It is herein demonstrated that that multifractal features are to a considerable extent similar for each type of monitoring station under warm atmospheric conditions and high solar radiation, owing to the fact that these weather characteristics homogenize the scaling behaviour of ozone. On the contrary, location and chemical precursors play a more prominent role under low temperatures and solar radiation, highlighting differences among multifractal features of ozone concentrations in the monitoring sites. At rural stations, the absence of anthropogenic emissions promotes less variability in ozone data and homogenization of multifractal behaviour throughout the year. Furthermore, a data shuffling procedure was performed in order to analyse changes occurring in multifractal spectra as time series are subjected to varying degrees of data position disturbance. Results indicate that multifractal analysis is a useful tool for describing the temporal scaling behaviour of ozone time series at different monitoring sites which refines results that have been traditionally provided by statistical analyses on ozone pollution.

In an attempt to analyze the chemical characterization of oil residues and examine the suitability of chemical fingerprinting methods in oil spill investigations, multiple parameters sensitive to both sources and degree of weathering were used to characterize oil residues from “7–16” Dalian oil spill, China. Oil residues collected 90days to 120days after the spill showed a weathering pattern where significant amounts of light to middle molecular weight normal alkanes were depleted with pristane and phytane as dominant peaks. Diagnostic ratios developed from n-alkane and selected isoprenoids (e.g. Pr/Ph, n-C17/Pr, n-C18/Ph, carbon preference index, LMW/HMW-alkanes ratio), all display obvious changes over weathering time, indicating that these ratios are not valid for oil source identification. Furthermore, the biomarker ratios of hopanes and steranes with relative standard deviations (RSDs) of 0.88–4.08% were useful for source identification even for severely weathered oil residues. In addition, RSD of δ13C values of individual n-alkanes in oil residue varied from 0.07% to 0.20%, which suggest that stable carbon isotope profile of n-alkanes can also be a useful tool for tracing the source of an oil spill.

Test facilities such as lab basins and wave tanks are essential when evaluating the use of chemical dispersants to treat oil spills at sea. However, these test facilities have boundaries (walls) that provide an ideal environment for surface (interfacial) film formation on seawater. Surface films may form from surfactants naturally present in crude oil as well as dispersant drift/overspray when applied to an oil spill. The objective of this study was to examine the impact of surface film formation on oil spreading rates in a small scale lab basin and on dispersant effectiveness conducted in a large scale wave tank. The process of crude oil spreading on the surface of the basin seawater was influenced in the presence of a surface film as shown using a 1st order kinetic model. In addition, interfacial film formation can greatly influence chemically dispersed crude oil in a large scale dynamic wave tank.

Organic matter removal by cultured Sesuvium portulacastrum in constructed floating beds was studied during a 20day greenhouse experiment and an 8month field campaign in the polluted Yundang Lagoon (southeastern China). Experiments were traced via dissolved organic carbon (DOC) concentration, fluorescence excitation–emission matrix and absorption spectroscopy. Two ‘terrestrial’ humic-like, one ‘marine’ humic-like and one protein-like components were identified by parallel factor analysis. The ‘terrestrial’ humic-like and protein-like components, DOC and absorption coefficient (a280) decreased during the greenhouse experiment. The intensities of four fluorescence components were all reduced during the field experiment. These results demonstrate the clear potential of floating bed phytoremediation techniques for reducing organic pollution degree in brackish environments. The rhizosphere may play an important role during phytoremediation. Our results show that spectrophotometric measurements such as fluorescence provide a useful tool for examining the removal of different organic moieties during various bioremediation processes.

Sources and transport processes of As, Cu, Cd and Pb were studied in different environmental compartments of Deception Island, an active volcano in the South Shetland Islands, Antarctica. Element concentrations in fresh water samples are consistent with the lowest values reported elsewhere in Antarctica. Interestingly, higher concentration values of As were found in samples collected in or near spring water courses and its transport may be related with processes of lixiviation in underground waters. While in saline waters Cu and Pb had important punctual sources, concentration values for Cd were consistently high pointing to the existence of a natural and diffuse source possibly related with the hydrothermal activity. The high Si/Al ratio, low carbon content, and a non-significant anthropogenic heavy metal input may explain the surprisingly homogeneous heavy metal content found in sediment samples.

We investigated the distribution patterns of the benthic foraminiferal assemblages outside the Pearl River Estuary in relation to trace metals, organic carbon and sedimentary particle fractions. The study area is unpolluted to moderately polluted by Cr, Cu, Pb and Zn and is completely polluted by Ni. The highest levels are found in the western coastal zone. Spatial distributions of the measured elements are strongly related to the behavior of the sedimentary clay fraction. The analyses of species abundance and community diversity as well as subsequent canonical correspondence analysis were used to reveal the relationship between foraminifera data and environmental parameters. Four sampling site groups established by factor analysis were distributed from the coastal area to the inner shelf. Their distribution patterns have a strong correlation with Cu, Pb and Ba. This research shows that benthic foraminifera can be used as bioindicators of trace metal pollutants outside the Pearl River Estuary.

The Deepwater Horizon Oil Spill resulted in the release of a large quantity of oil and gas into the northern Gulf of Mexico from a bathypelagic source. Due to a lack of pre-spill quantitative data the baseline condition of the communities near the spill site is unknown. This makes it difficult to determine the impact of the spill on deepwater megafauna. Remotely operated vehicles were used to quantify megafauna at five study sites during August and September 2010:2000m north, west, south, and east, and 500m north of the Macondo well. Comparisons of animal abundances indicated that 2000m-N and 2000m-W had the greatest taxonomic richness and highest abundances while 2000m-E had slightly lower values. In contrast 500m-N and 2000m-S had the lowest taxonomic richness and abundances. Our study also suggests that certain taxa were potentially more resistant or sensitive to the spill.