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Offshore oil spills often result in severe environmental and socio-economic consequences. This work focuses on a busy, yet poorly studied part of NW Europe, the Irish Sea, to assess the impact of future oil spills on the nearby coast. By integrating numerical models and shoreline sensitivity analyses for two confined areas, Liverpool Bay and Milford Haven, this work acknowledges wind direction and speed as principal controls on the movement of oil under winter/storm conditions and in shallow waters. Ocean currents play a secondary role, but are significant in deeper waters and in low-wind summer conditions. The temporal elements used in the modelling thus stress that when the spill occurs is just as important as where. As a corollary, the fate of spilled oil is determined in this work for distinct scenarios and types. Response strategies are recommended to minimise the impact of future spills on coastal populations. • Numerical models and shoreline sensitivity are analysed for two key areas of the Irish Sea. • Results stress the fact that when an oil spill occurs is just as important as where. • Wind influence is most important in winter/storm conditions and in shallow waters. • Ocean currents play a secondary role but are key in deep waters and with low winds. • Estuaries, bays and their associated habitats are very susceptible to the presence of oil. [ABSTRACT FROM AUTHOR]

Abstract Microplastics, an emerging pollutant, are recognised as having a ubiquitous distribution in the environment. Currently several benthic sampling tools are being employed to collect subtidal marine sediment, however, there are no comparative studies on the efficiency of these tools to sample for microplastics or the subsequent extraction methods of microplastics from these marine sediments. This study addresses these knowledge gaps by comparing commonly applied benthic sampling tools (Van Veen grab, box corer, gravity corer) and a variety of density separation methods (elutriation column, sodium chloride solution, sodium tungstate dihydrate solution) for microplastic collection and processing. Each sampling tool was tested at the same station and the collected sediment was used to assess the extraction performance for the different density separation techniques. No statistically significant differences were found between the concentrations of microplastics extracted for any of the sampling tools. However, there were significant differences between the density separation methods using sodium tungstate dihydrate and sodium chloride solution and the elutriation method. This preliminary study provides evidence that the sampling tools tested are both suitable and proficient at determining the abundance of microplastics in sediments. Sodium tungstate dihydrate proved to be a novel and feasible option for dense liquid separation of microplastics in subtidal marine sediments. These results will allow for more confidence in data quality when comparing future surveys applying different benthic sampling tools. Highlights • A new and efficient option for heavy liquid separation of MPs from marine sediments is Sodium tungstate dihydrate • Sodium chloride is the most feasible option for large scale monitoring purposes • All commonly used benthic grabs may be used for sampling microplastics in subtidal sediments • Elutriation design can hinder the efficiency and introduce contamination of sediment samples • Preliminary results show the sediment station sampled in Galway Bay had an average 104 microplastics per kg of dry sediment. [ABSTRACT FROM AUTHOR]

Ecosystem uptake and transfer processes of Sellafield-derived radiocarbon ( 14 C) within the Irish Sea were examined. Highly variable activities in sediment, seawater and biota indicate complex 14 C dispersal and uptake dynamics. All east basin biota exhibited 14 C enrichments above ambient background while most west basin biota had 14 C activities close to background, although four organisms including two slow-moving species were significantly enriched. The western Irish Sea gyre is a suggested pathway for transfer of 14 C to the west basin and retention therein. Despite ongoing Sellafield 14 C discharges, organic sediments near Sellafield were significantly less enriched than associated benthic organisms. Rapid scavenging of labile, 14 C-enriched organic material by organisms and mixing to depth of 14 C-enriched detritus arriving at the sediment/water interface are proposed mechanisms to explain this. All commercially important fish, crustaceans and molluscs showed 14 C enrichments above background; however, the radiation dose from their consumption is extremely low and radiologically insignificant. [ABSTRACT FROM AUTHOR]

Abstract: Beaufort’s Dyke is a disused ordnance disposal ground within the North Channel of the Irish Sea. Over 1 million tonnes of ordnance were disposed of in the dyke over a 40year period representing a substantial volume of trace metal pollutants introduced to the seabed. Utilising particle transport modelling software we simulated the potential transport of metal particles from Beaufort’s Dyke over a 3month period. This demonstrated that Beaufort’s Dyke has the potential to act as a source for trace metal contamination to areas beyond the submarine valley. Trace metal analysis of sediments from the Dyke and surrounding National Marine Monitoring Programme areas demonstrate that the Dyke is not the most contaminated site in the region. Particle transport modelling enables the transport pathways of trace metal contaminants to be predicted. Implementation of the technique in other munitions disposal grounds will provide valuable information for the selection of monitoring stations. [Copyright &y& Elsevier]

Abstract: We applied a three-dimensional general ocean and coastal circulation model to the Irish Sea in order to determine water renewal time scales in the region. The model was forced with meteorological data for 1995, a year with relatively warm summer and when extensive hydrographic surveys were conducted in the Irish Sea. We investigated intra-annual variability in the rates of net flow through the Irish Sea and carried out several flushing simulations based on conservative tracer transport. The results indicate that the net northward flow of 2.50km3/d is seasonally highly variable and under certain conditions is reversed to southward. The variability in obtained residence times is high; baroclinic effects are significant. Obtained results point at the importance of spatial and temporal consideration for transport of pollutants in the shelf seas. Implications for management are numerous and involve activities such as transport, fishing, use of resources, nature conservation, monitoring, tourism and recreation. [Copyright &y& Elsevier]

The amphipod crustacean Talitrus saltator is an established, easily accessible, biomonitor of trace metal bioavailabilities in coastal waters. We have carried out a geographically widespread collection of T. saltator from European shores, stretching from the north-west Atlantic through the Baltic to the Mediterranean. A primary aim of the work was to establish a database of accumulated trace metal concentrations (Cd, Cr, Cu, Fe, Mn and Zn) in this biomonitor. Statistical analysis has shown significant geographical differences in the bioavailabilities of all the metals, the most distinct being copper, iron and manganese. It has proved possible to identify unusually high accumulated concentrations of Cd, Cr, Cu, Fe, Mn and Zn in this biomonitor, indicative of high metal bioavailability at a particular site. These may serve as reference points for future biomonitoring programmes seeking to identify metal contamination in coastal waters. [Copyright &y& Elsevier]

The Irish Sea, which lies between 51°N–56°N and 2°50′W–7°W, provides a sheltered environment to exploit valuable fisheries resource. Anthropogenic activity is a real threat to its water quality. The majority of freshwater input down rivers flows into the eastern Irish Sea. The structure of the water circulation was not well understood during the planning of Sellafield nuclear plant outfall site in the eastern Irish Sea. A three-dimensional primitive equation numerical model was applied to the Irish Sea to simulate both barotropic and baroclinic circulation within the region. High accuracy was achieved with regard to the prediction of both tidal circulation and surface and nearbed water temperatures across the region. The model properly represented the Western Irish Sea Gyre, induced by thermal stratification and not known during planning Sellafield. Passive tracer simulations based on the developed hydrodynamic model were used to deliver residence times of the eastern Irish Sea region for various times of the year as well as travel times from the Sellafield outfall site to various locations within the Irish Sea. The results indicate a strong seasonal variability of travel times from Sellafield to the examined locations. Travel time to the Clyde Sea is the shortest for the autumnal tracer release (90 days); it takes almost a year for the tracer to arrive at the same location if it is released in January. Travel times from Sellafield to Dublin Bay fall within the range of 180–360 days. The average residence time of the entire eastern Irish Sea is around 7 months. The areas surrounding the Isle of Man are initially flushed due to a predominant northward flow; a backwater is formed in Liverpool Bay. Thus, elevated tracer concentrations are predicted in Liverpool Bay in the case of accidental spills at the Sellafield outfall site. [Copyright &y& Elsevier]

Surface seawater samples were collected in the Irish Sea and Liverpool Bay area from the R.V. Prince Madog during the period of 25–31 of March 2006. VOCs were purged with nitrogen, pre-concentrated on a SPME fibre and analysed immediately on a GC–MS. Target compounds quantified were halogenated (0.2–1400ngL−1), BTEXs and mono-aromatics (1.5–2900ngL−1), aliphatic hydrocarbons and others (0.6–15,800ngL−1). Day and night sampling was performed at a single station and suggested that factors such as sunlight and tide affect the presence of many of these compounds. Sample variability was high due to the variable weather conditions at the station. Poor correlations were found between marine phytopigments and selected VOCs. Principal component analysis (PCA) analysis showed that chlorinated compounds such as 1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethene, tetrachloroethene and carbon tetrachloride, predominantly from anthropogenic sources, originated from the River Mersey. Other brominated and iodinated compounds quantified were more likely to be from biogenic sources including novel marine compounds such as 2-chloropropane, 1-bromoethane and 1-chlorobutane. [Copyright &y& Elsevier]

Abstract: The isotopic composition and concentration of Pb was measured in suspended particulate matter of the Irish Sea. Aerosol, surficial and pre-industrial sediment was also analysed to provide information on sources terms. Concentrations of Pb in suspended sediments were lower than previously reported which presumably reflects the international effort to reduce Pb inputs to the environment. Lead concentrations were highest in Liverpool Bay and lowest in the western Irish Sea. A significant negative relationship between Pb and salinity suggests that present inputs and the resuspension of relict lead associated with particles in areas significantly affected by freshwater discharges are the predominant sources of Pb to the Irish Sea. The isotopic composition of Pb in the stratified region of the western Irish Sea demonstrates that atmospheric sources are also significant to this region, which is consistent with current knowledge on the hydrography. Pb isotopic ratios show that water entering the Irish Sea through St George’s Channel is significantly influenced by anthropogenic inputs prior to additional contamination by direct inputs to the Irish Sea. [Copyright &y& Elsevier]

Concentrations of the sum of 15 PAHs in 22 surficial sediment samples from the western Irish Sea ranged from below 100 ng g−1 in sandy sediments to a maximum of 1422 ng g−1 in the centre of the mud basin. The concentrations are typical of coastal shelf sediments, but greater than those observed for aquatic sediments remote from known anthropogenic sources. Organic C and the % sediment <15 μm were positively correlated with ΣPAH. ΣPAH was normalised to organic C and particle size (i.e. expressed as ΣPAH/Corg and ΣPAH/%<15 μm) and significant relationships were still observed with organic C and %<15 μm. The results are discussed in the context of using organic C to normalise concentrations of PAHs to assess contamination levels in sediments. [Copyright &y& Elsevier]

Focuses on sources and geochemical constraints of polycyclic aromatic hydrocarbons (PAH) in sediments and mussels of Northern Irish Sea-loughs. Role of geochemistry on PAH distribution; Indication of sources of PAH in sea-loughs; Reason for variations in concentrations of PAH in mussel population.

Focuses on the significance of imposex levels and tributyltin contamination in the red whelk Neptunea antiqua L. from the offshore Irish Sea. Presence of imposex in female whelks; Detection of low concentrations of butyltins in the soft tissues of the whelks; Correlation between the documented imposex stages and total butyltin contamination.

Ecosystem uptake and transfer processes of Sellafield-derived radiocarbon ( 14 C) within the Irish Sea were examined. Highly variable activities in sediment, seawater and biota indicate complex 14 C dispersal and uptake dynamics. All east basin biota exhibited 14 C enrichments above ambient background while most west basin biota had 14 C activities close to background, although four organisms including two slow-moving species were significantly enriched. The western Irish Sea gyre is a suggested pathway for transfer of 14 C to the west basin and retention therein. Despite ongoing Sellafield 14 C discharges, organic sediments near Sellafield were significantly less enriched than associated benthic organisms. Rapid scavenging of labile, 14 C-enriched organic material by organisms and mixing to depth of 14 C-enriched detritus arriving at the sediment/water interface are proposed mechanisms to explain this. All commercially important fish, crustaceans and molluscs showed 14 C enrichments above background; however, the radiation dose from their consumption is extremely low and radiologically insignificant., (Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Reports on planned increases in nuclear discharges into the Irish Sea from the Sellafield nuclear plant in Cumbria. Operation of the plant by British Nuclear Fuel Ltd. (BNFL); Allegations that BNFL plans to breach international commitments to reduce the discharges; Radioactivity found in seawater, sediments and marine life.

Mean concentrations of 137Cs and 40K in harbour porpoise are presented. Concentrations of 137Cs in porpoises originating from the Irish Sea were elevated relative to those from the Celtic Sea, Atlantic seaboard and the North Sea. Concentrations of 40K were comparable between samples from all locations and similar to those reported elsewhere. Concentration factors (CF) determined for Irish Sea porpoise did not differ significantly fromthose measured for other regions. The dose arising from 137Cs and 40K was dominated by the internal component. As most of the total dose was attributable to the naturally occurring 40K, it is unlikely that the increased dose due to the anthropogenic input of radionuclides has a detrimental effect on the healthof Irish Sea porpoise. Elevated concentrations of 137Cs in porpoises from the Irish Sea suggest they may be resident in the area. [ABSTRACT FROM AUTHOR]

Preceding the commissioning of EARP, concentrations of 99Tc in a large proportion of the Irish Sea were reasonably uniform (1-4 mBq 1-1). Increased levels from most recent discharges were observed along the Cumbrian and southern Scottish coastline. However, 99Tc concentrations decreased rapidly away from the coastline and were dispersed in a parallel direction to the shore, consistent with residual surface currents. Following elevated discharge periods, a significant pulse of 99Tc was rapidly transported northwards parallel to the shore. Post-EARP surveys indicate that the most rapid migration of 99Tc from the outfall to the North Channel was less than 3 months and the mean transit time is estimated to be in the order of 6 months. Comparison of UK coastal surveys, prior to and post EARP, suggest that 99Tc had migrated to the northern North Sea within some 9 months following the initial elevated discharge. [ABSTRACT FROM AUTHOR]