Enrichment of heavy metals was assessed in the Thi Vai Estuary and in the Can Gio Mangrove Forest (SE, Vietnam). Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn contents in water and in sediments were measured. Total organic carbon, nitrogen, phosphorus and C/N ratios were determined. Cu and Cr values were higher than threshold effect level of toxicity, while Ni exceeded probable effect level, indicating the risk of probable toxicity effects. Enrichment factors (EF), contamination factor (CF) and Geo-accumulation index (I-geo) were determined. CF reveals moderate to considerable pollution with Cr and Ni. EF suggests anthropogenic sources of Cr, Cu and Ni. I-geo indicates low contamination with Co, Cu and Zn and moderate contamination with Cr and Ni. Overall metal contents were lower than expected for this highly industrialized region, probably due to dilution, suggesting that erosion rates and hydrodynamics may also play a role in metal contents distribution.

An oil plume model to simulate the behavior of oil from spills located at any given depth below the sea surface is presented, following major modifications to a plume model developed earlier by Malačič (2001) and drawing on ideas in a paper by Yapa and Zheng (1997). The paper presents improvements in those models and numerical testing of the various parameters in the plume model. The plume model described in this paper is one of the numerous modules of the well-established MEDSLIK oil spill model. The deep blowout scenario of the MEDEXPOL 2013 oil spill modelling exercise, organized by REMPEC, has been applied using the improved oil plume module of the MEDSLIK model and inter-comparison with results having the oil spill source at the sea surface are discussed.

Fifty-one surface sediment samples were collected from eleven sea areas along the Guangdong coast in southern China. Biogenic elements, metals and dinoflagellate cysts were analyzed. Twenty-one cyst taxa in 12 genera were identified. The cyst concentrations ranged between 14 and 250 cysts/g, with an average of 69 cysts/g. The low cyst production was caused by coarse sediments, high sedimentation rates, and high anthropogenic disturbances. Biogenic elements were comparable with those reported. However, the metal concentrations were far lower than the sediment quality guidelines. Both biogenic elements and metals were higher in the Mid Coast and lower in the Western Coast. Eutrophication slightly enhanced the productivity of autotrophic dinocysts, and cysts of Scrippsiella indicated eutrophication. Cd had inhibitory effects on cyst production. Alexandrium and Diplopsalis cysts were sensitive to metal contamination; however, Gyrodinium, Pheopolykrikos, and Lingulodinium cysts had high resistance to metal contamination.

Ongoing bioremediation research seeks to promote naturally occurring microbial polycyclic aromatic hydrocarbon (PAH) degradation during and after oil spill events. However, complex relationships among functionally different microbial groups, nutrients and PAHs remain unconstrained. We conducted a surface water survey and corresponding nutrient amendment bioassays following the Texas City “Y” oil spill in Galveston Bay, Texas. Resident microbial groups, defined as either heterotrophic or autotrophic were enumerated by flow cytometry. Heterotrophic abundance was increased by oil regardless of nutrient concentrations. Contrastingly, autotrophic abundance was inhibited by oil, but this reaction was less severe when nutrient concentrations were higher. Several PAH compounds were reduced in nutrient amended treatments relative to controls suggesting nutrient enhanced microbial PAH processing. These findings provide a first-look at nutrient limitation during microbial oil processing in Galveston Bay, an important step in understanding if nutrient additions would be a useful bioremediation strategy in this and other estuarine systems.

We investigated the origin and distribution of aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs) and organic matter (OM) in surficial sediments of the Sfax-Kerkennah channel in the Gulf of Gabès (Tunisia, Southern Mediterranean Sea). TOC, AH and PAH concentrations ranged 2.3–11.7%, 8–174μgg−1sed.dw and 175–10,769ngg−1sed.dw, respectively. The lowest concentrations were recorded in the channel (medium sand sediment) and the highest ones in the Sfax harbor (very fine sand sediment). AHs, PAHs and TOC were not correlated for most of the stations. TOC/N and δ13C values revealed a mixed origin of OM with both marine and terrestrial sources. Hydrocarbon molecular composition highlighted the dominance of petrogenic AHs and the presence of both petrogenic and pyrogenic PAHs, associated with petroleum products and combustion processes. This work underscores the complex distribution patterns and the multiple sources of OM and hydrocarbons in this highly anthropogenized coastal environment.

Polycyclic aromatic hydrocarbons are very important components of oil pollution. These pollutants tend to sorb to cell surfaces, exerting toxic effects on organisms. Our study developed a flow cytometric method for the detection of PAHs sorbed to phytoplankton by exploiting their spectral characteristics. We discriminated between cells with PAHs from cells free of PAHs. Clear discrimination was observed with flow cytometer provided with 375 or 405nm lasers in addition to the standard 488nm laser necessary to identify phytoplankton. Using this method, we measured the relationship between the percentages of phytoplankton organisms with PAHs, with the decrease in the growth rate. Moreover, the development of this method could be extended to facilitate the study of PAHs impact on cell cultures from a large variety of organisms.

The Straits of Malacca is one of the world's busiest shipping routes where frequent oil spills occur. Rapid development in the west coast of Peninsular Malaysia is the other major source of petroleum pollution in this narrow waterway. In order to identify occurrence and origin of hydrocarbons in the Straits, mangrove oysters (Crassostrea belcheri) were collected from five sampling locations and analysed for n-alkanes and biomarkers. Soxhlet apparatus and two step column chromatography were used for extraction, purification and fractionation of the oysters. Petroleum origin n-alkanes were detected in majority of the sampling locations which is indicative of anthropogenic activities in this region. Using source and maturity diagnostic ratios for hopanes revealed used crankcase oil as the main source of petroleum hydrocarbons in oysters from all sampling locations except for the Pulau Merambong where signature of South East Asia crude oil (SEACO) was detected.

Dinoflagellate community structure from two semi-enclosed areas along the South Andaman region, India, was investigated to assess the anthropogenic impact on coastal water quality. At the densely inhabited Port Blair Bay, the dominance of mixotrophs in water and Protoperidinoids in sediments was attributed to anthropogenic nutrient enrichment and prey availability. A significant decrease in dinoflagellate abundance from inner to outer bay emphasize the variation in nutrient availability. The dominance of autotrophs and Gonyaulacoid cysts at the North Bay highlight low nutrient conditions with less anthropogenic pressure. The occurrence of oceanic Ornithocercus steinii and Diplopsalis sp. could evince the oceanic water intrusion into the North Bay. Nine potentially harmful and red-tide-forming species including Alexandrium tamarense complex, A. minutum were identified in this study. Although there are no harmful algal bloom (HABs) incidences in this region so far, increasing coastal pollution could support their candidature towards the future HABs initiation and development.

South Atlantic studies referring to non-native taxa are mostly restricted to Argentinean, Brazilian, and South African coasts. In this study we examined the literature to provide a list of sessile marine invertebrates along the Angolan coast, to infer its introduction status according to their biogeographical distribution and natural history. We reported 29 non-native and 7 cryptogenic species, a small number when compared to other South Atlantic regions of similar extension. Half of the non-native species were reported for Luanda. The majority of the introduced species had a northern hemisphere origin, a consequence of the main introduction route being from the North Atlantic/Mediterranean Sea during the Portuguese colonization. This is the first comprehensive assessment of this kind for the Angolan coast and the diversity of introduced species is certainly underestimated. Regular and rigorous assessments and monitoring of introduced marine species will help to understand the vectors, routes and time of introductions.

The Magellanic penguin (Spheniscus magellanicus) is a marine sentinel for the southern Atlantic Ocean that is a proxy of environmental quality. The presence of marine debris (macro-debris) in the stomach contents of emaciated juvenile penguins stranded from 21°S to 23°S was compared at different times (2000 and 2008), and the debris ingestion pathway was determined. The frequency of marine debris in the stomachs doubled in less than a decade, and flexible plastics remained the main ingested item over time (68–70%). The pelagic octopus, Argonauta nodosa, which inhabits the sea surface, was the most important prey species recovered in the stomach contents. The poor physical condition of the penguins that reach the northern migration limit (study area) reduces the diving capacity of the animals and increases their vulnerability to debris ingestion. Considering their preferred prey and physical condition, we conclude that the penguins likely ingested the marine debris in surface waters.