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Applying underwater released exhaust gas as ‘air lubrication’ along the ship’s hull to reduce the energy consumption is under development. However, this direct emission to the water could pose a risk to the local marine environment, especially in shipping-dense areas. Specifically, CO2, a dominant component in the exhaust gas, has the potency to enhance algal blooms and cause acidification. This study provides the first relative risk assessment of ships with underwater release exhaust gas systems on a global scale, taking into account local water conditions and shipping intensity. Risk was characterized for 262 marine ecoregions by plotting the expected CO2 emission from ships to water against the estimated vulnerability to acidification and algal blooms. The vulnerability of each ecoregion was assessed based on background dissolved inorganic carbon (DIC) level, chlorophyll-a concentrations and total alkalinity. The results reveal that areas with relatively high vulnerability are mainly located above 30° N latitude. The Yellow Sea, Southern China Sea, and North Sea come out as relatively high risk areas. Looking in more detail to European high-risk ecoregions, the highest risk levels are found in areas with dense shipping lanes and maritime chokepoints, e.g. the Strait of Dover and the Strait of Gibraltar. This was the first attempt to make such a risk assessment and the outcome is only indicative. In a next phase additional parameters, such as water currents and biological composition of the ecosystem should be included.Key PointsThe first global environmental risk assessment was made for innovative ships that apply underwater released exhaust gas as ‘air lubrication’Ecoregions with relatively high vulnerability to acidification and algal blooms are mainly located above 30° N latitudeThe risk for the marine ecosystem of the underwater released exhaust CO2 from ships is limited to specific shipping-dense areas

Marine filter feeders are exposed to microplastic because of their selection of small particles as food source. Baleen whales feed by filtering small particles from large water volumes. Macroplastic was found in baleen whales before. This study is the first to show the presence of microplastic in intestines of a baleen whale (Megaptera novaeangliae). Contents of its gastrointestinal tract were sieved, dissolved in 10% potassium hydroxide and washed. From the remaining dried material, potential synthetic polymer particles were selected based on density and appearance, and analysed by Fourier transform infrared (FTIR) spectroscopy. Several polymer types (polyethylene, polypropylene, polyvinylchloride, polyethylene terephthalate, nylon) were found, in varying particle shapes: sheets, fragments and threads with a size of 1 mm to 17 cm. This diversity in polymer types and particle shapes, can be interpreted as a representation of the varying characteristics of marine plastic and the unselective way of ingestion by M. novaeangliae.

During the development of an embryo into a juvenile, the physiology and behavior of a fish change greatly, affecting exposure to and uptake of environmental pollutants. Based on experimental data with sole (Solea solea), an existing bioaccumulation model was adapted and validated to calculate the development of concentrations of persistent organic pollutants in the tissue of developing fish. Simulation revealed that toxic tissue concentrations of pollutants with log octanol–water partition ratio (KOW) > 5 peak at the moment when the larvae become free-feeding, when the lipid reserves are depleted. This may explain the delayed effects observed in fish early-life-stage experiments with exposed eggs. In the field, eggs can be exposed through maternal transfer to adult pollutant tissue concentrations, which will increase in the larva to peak tissue concentrations, exceeding those of the adult fish. The results demonstrate the risk of underestimating the effects of lipophilic persistent organic pollutants with log KOW > 5 in short-term, early-life-stage fish tests and underscore the importance of maternal transfer as an exposure route in the field situation. Environ. Toxicol. Chem. 2012;31:1381–1390. © 2012 SETAC

Highlights: • We review research since 2005 on potential impacts of leakage from CO2 storage. • We consider near surface onshore and offshore impacts and those on potable groundwaters. • Low level leakage through faults or wells is likely to be limited and recovery rapid. • Effects are reduced by mixing, dispersion and buffering. • Larger leaks are possible but less likely and should be easier to detect and remedy. Abstract: This paper reviews research into the potential environmental impacts of leakage from geological storage of CO2 since the publication of the IPCC Special Report on Carbon Dioxide Capture and Storage in 2005. Possible impacts are considered on onshore (including drinking water aquifers) and offshore ecosystems. The review does not consider direct impacts on man or other land animals from elevated atmospheric CO2 levels. Improvements in our understanding of the potential impacts have come directly from CO2 storage research but have also benefitted from studies of ocean acidification and other impacts on aquifers and onshore near surface ecosystems. Research has included observations at natural CO2 sites, laboratory and field experiments and modelling. Studies to date suggest that the impacts from many lower level fault- or well-related leakage scenarios are likely to be limited spatially and temporarily and recovery may be rapid. The effects are often ameliorated by mixing and dispersion of the leakage and by buffering and other reactions; potentially harmful elements have rarely breached drinking water guidelines. Larger releases, with potentially higher impact, would be possible from open wells or major pipeline leaks but these are of lower probability and should be easier and quicker to detect and remediate.

To quantify the occurrence of ingested plastic in fish species caught at different geographical positions in the North Sea, and to test whether the fish condition is affected by ingestion of plastics, 1203 individual fish of seven common North Sea species were investigated: herring, gray gurnard, whiting, horse mackerel, haddock, atlantic mackerel, and cod. Plastic particles were found in 2.6% of the examined fish and in five of the seven species. No plastics were found in gray gurnard and mackerel. In most cases, only one particle was found per fish, ranging in size from 0.04 to 4.8 mm. Only particles larger than 0.2 mm, being the diameter of the sieve used, were considered for the data analyses, resulting in a median particle size of 0.8 mm. The frequency of fish with plastic was significantly higher (5.4%) in the southern North Sea, than in the northern North Sea above 55°N (1.2%). The highest frequency (>33%) was found in cod from the English Channel. In addition, small fibers were initially detected in most of the samples, but their abundance sharply decreased when working under special clean air conditions. Therefore, these fibers were considered to be artifacts related to air born contamination and were excluded from the analyses. No relationship was found between the condition factor (size–weight relationship) of the fish and the presence of ingested plastic particles.

The RISCS (Research into Impacts and Safety in CO2 Storage) project is studying potential impacts of leakage from CO2 storage on marine and terrestrial ecosystems. Although storage sites will be designed for zero leakage it is important to consider the po

Dichlofluanid (N-dichlorofluoromethylthio-N′-dimethyl-N- phenylsulphamide) is used as booster biocide in antifouling paints. The occurrence of dichlofluanid and its metabolite DMSA (N′-dimethyl-N-phenyl- sulphamide) was monitored in seawater and marine sediment from three Greek marinas. Seawater and sediment samples were collected at three representative positions and one suspected hotspot in each marina and shipped to the laboratory for chemical analysis. As part of the project, an analytical method had been developed and validated. Furthermore, some additional experiments were carried out to investigate the potential contribution of paint particle bound dichlofluanid on the total concentration in the sediment. As expected, given its known high hydrolytic degradation rate, no detectable concentrations of dichlofluanid were measured in any of the seawater samples. DMSA was detected in seawater samples at very low concentrations varying from

The Predicted No Effect Concentration (PNEC) for dissolved copper based on the species sensitivity distribution (SSD) of 24 marine single species tests was validated in marine mesocosms. To achieve this, the impact of actively maintained concentrations of dissolved copper on a marine benthic and planktonic community was studied in 18 outdoor 4.6m3 mesocosms. Five treatment levels, ranging from 2.9 to 31μg dissolved Cu/L, were created in triplicate and maintained for 82days. Clear effects were observed on gastropod and bivalve molluscs, phytoplankton, zooplankton, sponges and sessile algae. The most sensitive biological endpoints; reproduction success of the bivalve Cerastoderma edule, copepod population development and periphyton growth were significantly affected at concentrations of 9.9μg Cu/L and higher. The No Observed Effect Concentration (NOEC) derived from this study was 5.7μg dissolved Cu/L. Taking into account the DOC concentration of the mesocosm water this NOEC is comparable to the PNEC derived from the SSD.

This PhD project assessed the potential environmental impact of innovative GasDrive ships with more efficient and cleaner engines that release exhaust gas underwater to reduce water resistance by air lubrication. CO2 in the exhausted gas was identified as the major impactor and caused acidification. This had a significant community impact via direct effects on invertebrate species and indirect influence on the less sensitive species via the food chain. Especially less sensitive microalgae will profit from CO2 as micronutrient, potentially inducing an algal bloom especially with reduced grazer presence. Based on these findings a preliminary risk assessment of underwater released exhaust CO2 was carried out from a global marine perspective. In the worst-case scenario, adverse environmental effects are to be expected in the busiest shipping lanes only. Further attention should be given to the occupational risk for the crew, the potential antifouling effect and the generation of underwater noise.

Chemicals may affect the ecological quality of environmental compartments such as surface waters. In order to assess the environmental risks, the effects of these chemicals are tested in laboratories with specific organisms exposed to a range of concentrations. Information generated with such tests is often stored in large databases. When environmental risk is assessed, such databases are consulted before new tests are performed. This is to prevent unnecessary experiments that cost animals, time and money. Of course, existing data should be of sufficient quality for the intended purpose, certain, accurate, reliable and relevant. In this thesis, approaches to judge and apply these aspects are evaluated and improvements suggested. The data selection needs to be explicitly motivated, and should be iteratively adjusted when the assessment based on the selection does not meet with the intended requirements for risk assessment.

Although plastic has unquestionable benefits to modern society, its current use leads to pollution of the environment. Via direct disposal and degradation of larger plastic items, microplastic and nanoplastic particles reach the environment. Potential negative effects include ecological harm to species due to particle effects of plastic and effects of plastic on the transfer of chemicals between organisms and the environment. The particle characteristics as well as many environmentally relevant processes affect the fate of micro- and nanoplastic particles, the exposure, effects and consecutive risk to organisms. This thesis addresses a great number of these characteristics and processes in depth from the riverine towards the marine environment and combines these with other fate and effect studies from the literature to derive a provisional quantitative analysis of the ecological risk of micro- and nanoplastic in the aquatic environment.

The Deepwater Horizon (DWH) oil spill in the Gulf of Mexico in 2010 was one of the largest oil spills in history. For three months, oil leaked from the Macondo well at 1,500 m depth into the Gulf. As one of the spill responses, an unprecedented amount of dispersants were applied, both at the sea surface and, for the first time ever, directly injected into the wellhead. During the spill, unusually large amounts of marine snow, including Extracellular Polymeric Substances (EPS), were formed. Oil-contaminated marine snow aggregates were formed by aggregation of EPS with suspended solids, phytoplankton cells due to the spring bloom, and the dispersed oil droplets. The marine snow sank through the water column and settled on the ocean floor. This process was named MOSSFA: Marine Oil Snow Sedimentation and Flocculent Accumulation. MOSSFA was an important pathway of transferring oil to the deep-sea, and 14-21% of the total discharged oil is estimated to have settled on the sediment, where it impacted the benthic ecosystem. This thesis focused first on the mechanism of EPS snow formation, and then more in depth on the additional ecotoxicological consequences of marine snow formation during oil spills for the benthic ecosystem. Chapter 2 describes the role of chemical dispersants in the presence of phytoplankton in the formation of EPS, one of the main ingredients of marine snow. Results show that phytoplankton-associated bacteria were responsible for the EPS formation, and the symbiosis between the phytoplankton and its associated bacterial community provided the bacteria with energy to produce the EPS. The microcosm experiment in Chapter 3 investigated the effect of marine snow on oil biodegradation in microcosms without benthic macroinvertebrates. Results showed that marine snow hampers oil biodegradation: the presence of marine snow reduced the depletion of oil alkanes by 40%, most likely due to the high biodegradability of marine snow organics compared to the oil. Biodegradation of marine snow resulted in anaerobic conditions in the top of the sediment layer. This reduced the oil biodegradation. Marine snow thus prolongs the residence time of oil in the benthic ecosystem. The next microcosm experiment, described in Chapter 4, investigated the effects of oil-contaminated marine snow on benthic macroinvertebrates, and the effect of macroinvertebrates on oil biodegradation. Bioturbation by the invertebrates increased the oxygenated top layer of the sediment and partly counterbalanced the inhibition of oil biodegradation due to oxygen consumption by marine snow. Survival of three benthic invertebrate species was reduced by (oil-contaminated) marine snow. Oxygen depletion near the sediment surface seemed to be the main reason for the observed adverse effects of the marine snow. In addition, indications were found that some species used the marine snow as food source, even when it was oil-contaminated. In the last microcosm experiment, described in Chapter 5, two benthic invertebrate species were monitored over a period of 42 days after which new animals were introduced and observed for an additional period of 22 days. Marine snow degradation again resulted in lower dissolved oxygen concentrations in the water column, which inhibited oil biodegradation on the sediment compared to oil in combination with clay. The oxygenated top layer of the sediment disappeared, and recovered after ~20 days. At the end of the experiment, mudsnails from the treatments with oiled marine snow had higher PAH concentrations in their tissues than the animals from the treatments with the same amount of oil in clay only, confirming the use of marine snow as food source. Overall, oil-contaminated marine snow on the ocean sediment can negatively affect benthic ecosystems, and can hamper oil biodegradation and ecosystem recovery. The additional consequences of MOSSFA during oil spills and spill responses should be taken into account in oil spill response planning.