Three mangroves species with differential propagule size, Avicennia marina (2.5±0.3cm), Bruguiera gymnorrhiza (16±2cm) and Rhizophora mucronata (36±3cm), were subjected to oil contamination. In a series of glasshouse and field experiments, the sediment, propagules, leaves and stems were oiled and growth monitored. Oiling of the propagules, leaves, internodes or sediment reduced plant height, leaf number, leaf chlorophyll content index and induced growth abnormalities, leaf abscission and mortality, with effects being greatest in A. marina, intermediate in R. mucronata and least in B. gymnorrhiza. The results suggest that the greater susceptibility of A. marina to oil is due to early shedding of the protective pericarp and rapid root and shoot development after detachment from the parent tree and not to propagule size. After seedling emergence, micromorphological factors such as presence of trichomes, salt glands and thickness of protective barriers influence oil tolerance.

We utilize N and C species concentration data along with δ15N values of NO3− and δ13C values of dissolved inorganic C to evaluate the stoichiometry of biogeochemical reactions (mineralization, nitrification, anammox, and denitrification) occurring within a subsurface wastewater plume that originates as treated wastewater injection and enters the coastal waters of Maui as submarine groundwater discharge. Additionally, we compare wastewater effluent time-series data, injection rates, and treatment history with submarine spring discharge time-series data. We find that heterotrophic denitrification is the primary mechanism of N loss within the groundwater plume and that chlorination for pathogen disinfection suppresses microbial activity in the aquifer responsible for N loss, resulting in increased coastal ocean N loading. Replacement of chlorination with UV disinfection may restore biogeochemical reactions responsible for N loss within the aquifer and return N-attenuating conditions in the effluent plume, reducing N loading to coastal waters.

The crude oil drilling and extraction operations are aimed to maximize the production may be counterbalanced by the huge production of contaminated produced water (PW). PW is conventionally treated through different physical, chemical, and biological technologies. The efficiency of suggested hybrid electrobiochemical (EBC) methods for the simultaneous removal of total petroleum hydrocarbon (TPH) and sulfate from PW generated by petroleum industry is studied. Also, the factors that affect the stability of PW quality are investigated. The results indicated that the effect of biological treatment is very important to keep control of the electrochemical by-products and more TPH removal in the EBC system. The maximum TPH and sulfate removal efficiency was achieved 75% and 25.3%, respectively when the detention time was about 5.1min and the energy consumption was 32.6mA/cm2. However, a slight increasing in total bacterial count was observed when the EBC compact unit worked at a flow rate of average 20L/h. Pseudo steady state was achieved after 30min of current application in the solution. Also, the results of the study indicate that when the current intensity was increased above optimum level, no significant results occurred due to the release of gases.

This paper presents a model of oil weathering and transport in sea ice. It contains a model formulation and scenario simulation to test the proposed model. The model formulation is based on state-of-the-art models for individual weathering and transport processes. The approach incorporates the dependency of weathering and transport processes on each other, as well as their simultaneous occurrence after an oil spill in sea ice. The model is calibrated with available experimental data. The experimental data and model prediction show close agreement. A sensitivity analysis is conducted to determine the most sensitive parameters in the model. The model is useful for contingency planning of a potential oil spill in sea ice. It is suitable for coupling with a level IV fugacity model, to estimate the concentration and persistence of hydrocarbons in air, ice, water and sediments for risk assessment purposes.

The objective of this study was to assess the environmental conditions of a heavily polluted marine habitat using descriptors of fish parasites. Epinephelus coioides from Jakarta Bay as well as off Jakarta Bay was studied for metazoan parasites. Based on 70 fish and considering previous studies (230 fish), an environmental indicator system was designed. Including the recent study, a total of 51 parasite species have been recorded for E. coioides in Indonesian waters. Seven of them combined with five parasitological indices are useful descriptors for the environmental status of marine ecosystems. The results are visualized in a star graph. A significant different parasite infection between nine analyzed localities demonstrates the negative influence of the megacity Jakarta onto the coastal environment. We herewith complete a parasite based indicator system for Indonesian coastal waters, and suggest that it can be used in other marine habitats as well as for further epinephelids.

Recent at sea surveys of floating macro-debris in the southeast Atlantic Ocean found that debris increases in size with distance from shore, suggesting that many smaller items, which dominate litter close to urban source areas, sink before dispersing far into the ocean. We test whether this pattern is evident in beach litter in the same region. Freshly stranded beach litter was collected at increasing distances (0km, 100km, 200km and 2800km) from Cape Town, a major urban litter source. Mean size and buoyancy of litter items increased significantly with distance from Cape Town. Size-specific sedimentation due to the ballasting effect of biofouling is a plausible explanation for the disappearance of smaller, less buoyant items. Our results provide further evidence that many low buoyancy items sink and support the hypothesis that size and buoyancy are strong predictors of dispersal distance for floating debris.

As part of risk assessment of fuel oil spills in Antarctic and subantarctic waters, this study describes partitioning of hydrocarbons from three fuels (Special Antarctic Blend diesel, SAB; marine gas oil, MGO; and intermediate grade fuel oil, IFO 180) into seawater at 0 and 5°C and subsequent depletion over 7days. Initial total hydrocarbon content (THC) of water accommodated fraction (WAF) in seawater was highest for SAB. Rates of THC loss and proportions in equivalent carbon number fractions differed between fuels and over time. THC was most persistent in IFO 180 WAFs and most rapidly depleted in MGO WAF, with depletion for SAB WAF strongly affected by temperature. Concentration and composition remained proportionate in dilution series over time. This study significantly enhances our understanding of fuel behaviour in Antarctic and subantarctic waters, enabling improved predictions for estimates of sensitivities of marine organisms to toxic contaminants from fuels in the region.

A Lagrangian model which simulates the dispersion of 137Cs in the North Atlantic has been developed. The model includes water/sediment interactions. It has been tested comparing calculated and measured 137Cs concentrations in water and sediments of the European Shelf resulting after the releases from the nuclear fuel reprocessing plants of Sellafield and La Hague. Some additional numerical experiments have been carried out. First, the redissolution of 137Cs from contaminated sediments after the reduction in releases from the reprocessing plants has been studied. This allowed to calculate effective half-lives of 137Cs in several sub-basins. Later, potential leakage of 137Cs from dumped nuclear wastes in several locations of the Atlantic has been investigated. Even in worst-case scenarios, these leakages should not lead to any radiological implications.

Polybrominated diphenyl ethers (PBDEs) are widely dispersed persistent organic pollutants in the marine ecosystem. However, their toxic mechanisms in marine organisms, especially invertebrates, remain poorly understood. Two common congeners of PBDEs, tetrabrominated diphenyl ether-47 (BDE-47) and decabrominated diphenyl ether-209 (BDE-209), were investigated. Their toxic mechanisms, with a focus on oxidative stress, were examined in rotifer Brachionus plicatilis. Overproduction of reactive oxygen species (ROS) was induced by two PBDEs. The expression of superoxide dismutase (SOD) mRNA was increased, suggesting SOD play a main role in ROS-scavenging. The intercellular concentrations of calcium ([Ca2+]in) and the expression of calmodulin (CaM) mRNA were increased. This indicates the calcium ion (Ca2+) signaling channel is involved in PBDEs stress. Further analysis showed that the reproductive system might be the target site for toxicity of PBDEs. Moreover, high value of detection indexes in BDE-47 experimental groups suggested BDE-47 might cause higher oxidative damage than BDE-209 in rotifers.

A need exists for appropriate tools to evaluate risk and monitor potential effects of contaminants in tropical marine environments, as currently impact assessments are conducted by non-representative approaches. Here, a novel bioassay is presented that allows for the estimation of the chronic toxicity of contaminants in receiving tropical marine environments. The bioassay is conducted using planktonic larvae of the barnacle Amphibalanus amphitrite and is targeted at generating environmentally relevant, chronic toxicity data for water quality guideline derivation or compliance testing. The developmental endpoint demonstrated a consistently high control performance, validated through the use of copper as a reference toxicant. In addition, the biological effects of aluminium, gallium and molybdenum were assessed. The endpoint expressed high sensitivity to copper and moderate sensitivity to aluminium, whereas gallium and molybdenum exhibited no discernible effects, even at high concentrations, providing valuable information on the toxicity of these elements in tropical marine waters.