Spatial and temporal analysis of the risks posed by metal contamination in coastal and marine sediments of Bahrain.

Nine metals including Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were analysed from sediment samples collected from 29 stations since 2007 from Bahraini waters. Within this study, it was investigated whether concentrations of these determinants are at concentrations above internationally established Assessment Criteria (AC). The majority of sites were considered not to pose a toxicological risk in terms of metal contamination. Where breaches occurred, they were mainly from historic samples related to Cr, Cu and Ni contamination. A trend assessment revealed that out of 59 significant trends, 36 were downwards and 23 upwards, indicating that some determinants like Al, Zn and Ni are improving strongly across some sites, whilst areas associated with industrial activity still see some increasing trends for Al, Cd, Pb and Zn.

A seafood risk tool for assessing and mitigating chemical and pathogen hazards in the aquaculture supply chain.

Intricate links between aquatic animals and their environment expose them to chemical and pathogenic hazards, which can disrupt seafood supply. Here we outline a risk schema for assessing potential impacts of chemical and microbial hazards on discrete subsectors of aquaculture-and control measures that may protect supply. As national governments develop strategies to achieve volumetric expansion in seafood production from aquaculture to meet increasing demand, we propose an urgent need for simultaneous focus on controlling those hazards that limit its production, harvesting, processing, trade and safe consumption. Policies aligning national and international water quality control measures for minimizing interaction with, and impact of, hazards on seafood supply will be critical as consumers increasingly rely on the aquaculture sector to supply safe, nutritious and healthy diets.

Aquatic contaminants in Solomon Islands and Vanuatu: Evidence from passive samplers and Microtox toxicity assessment.

Water Quality issues in many Pacific countries are rising, with the increase in coastal populations and associated urban runoff but management requires contamination issues in the aquatic environment to be identified and prioritised. In Vanuatu and Solomon Islands there are few laboratories and resources to assess for the presence or impact of complex chemical contaminants. The extent and impact of chemical contamination of the marine and coastal environment is poorly described. Passive chemical samplers were used to measure a range of aquatic pollutants around the capital cities, Honiara (Solomon Islands) and Port Vila (Vanuatu). We detected a range of chemicals indicative of agricultural and industrial contamination and a few sites had concerning concentrations of specific hydrocarbons and pesticides. The rapid ecotoxicology test, Microtox, indicated toxic impacts in rivers, coastal sites and urban drains This work provides new data on chemical contamination and possible impacts of that contamination for both countries. The techniques could be applied widely across the region to generate critical data for environmental management, guide monitoring efforts and measure the impact of policy or land-use changes.

Kuwait's marine biodiversity: Qualitative assessment of indicator habitats and species.

The tropical waters of the Northern Arabian Gulf have a long history of maritime resource richness. High levels of biodiversity result from the complex matrix of coastal habitats, coral reefs and sea grass beds that characterise the region. Insight into the ongoing health of such habitats and the broader Kuwait maritime environment can be gauged by the status of indicator species found within these habitats. Here we review information on the occurrence, distribution and threats to key marine habitats and associated indicator species to provide an updated assessment of the state of the Kuwait's marine biodiversity. Critical evaluation of historic data highlights knowledge gaps needed inform the focus of future monitoring and conservation efforts. This assessment is designed to evaluate performance against environmental policy commitments, while providing a solid foundation for the design of comprehensive marine ecosystem management strategies.

Baseline survey of marine sediments collected from the Kingdom of Bahrain: PAHs, PCBs, organochlorine pesticides, perfluoroalkyl substances, dioxins, brominated flame retardants and metal contamination.

A baseline survey of sediment contamination was undertaken at 14 locations around the coastline of Bahrain in May 2017, followed by a focused survey of 20 sites, in November 2019. Samples were assessed for industrial pollutants, including metals, PAHs and a suite of organohalogen compounds. The data generated indicated that levels of chemical contaminants were generally low and did not pose a toxicological risk when assessed against commonly applied sediment quality guidelines (SQG). The highest concentrations of PAHs and PCBs were identified in samples collected at coastal sites adjacent to a refinery area known to contain a diverse mix of industry. Tubli Bay, a heavily stressed small bay receiving high loads of sewage effluent, was also identified as an area warranting further investigation with elevated concentrations of BDE209, PFOS and metal contamination. Such data provides a useful baseline assessment of sediment contamination, against which management control measures can be assessed.

Marine plastic litter in the ROPME Sea Area: Current knowledge and recommendations.

The impact of marine litter, particularly plastic waste, is widely acknowledged as a growing global concern. Marine litter is an understudied issue in the Regional Organisation for Protection of the Marine Environment (ROPME) Sea Area where rapid economic growth has already placed considerable stress on infrastructure and coastal ecosystems. This paper outlines some of the drivers for waste generation in region and reviews the available literature to summarise the current state of knowledge on the environmental fate, behaviour and impact of marine litter within the ROPME Sea Area. While data is limited, those studies conducted demonstrate marine litter is posing a clear and growing threat to the environmental and socioeconomic prosperity of the ROPME Sea Area. The development of regional and national marine litter reduction plans are clearly a priority to focus and coordinate activity across multiple stakeholders. Discussion of the potential environmental impacts arising as a result of marine litter are presented together with a roadmap for establishing and implementing a ROPME Sea Area Marine Litter and Single-Use Plastic Action Plan.

Spatial and temporal variation of three biomarkers in Mytilus edulis.

Environmental conditions and xenobiotic exposure can be sources of stress to living organisms. Biological markers are measurable indicator of changes which may happen at any biological level and which can be considered an early warning signal of some biological or environmental state or condition. A structured field study was undertaken to investigate the relationship between three biomarker assays and the spatial and temporal variation of each biomarker in samples of Mytilus edulis. The three biomarkers were the neutral red retention assay, micronucleus assay and comet assay, which indicate damage at different cellular/molecular levels. Three sites in Poole Harbour, an area on the South coast of the UK were sampled on six separate occasions at least three weeks apart. The results for the comet assay showed a significant difference between sites and between sampling dates whereas the results for the other two assays did not show a significant difference for either factor. There was no significant correlation between the results of any pair of the three biomarkers. The results of the micronucleus assay showed a significant correlation with water temperature. This temperature effect, as well as induced repair, may contribute to explain the lack of a strict correspondence between pollution gradients and biomarkers responses.

Below the surface: Twenty-five years of seafloor litter monitoring in coastal seas of North West Europe (1992-2017).

Marine litter presents a global problem, with increasing quantities documented in recent decades. The distribution and abundance of marine litter on the seafloor off the United Kingdom's (UK) coasts were quantified during 39 independent scientific surveys conducted between 1992 and 2017. Widespread distribution of litter items, especially plastics, were found on the seabed of the North Sea, English Channel, Celtic Sea and Irish Sea. High variation in abundance of litter items, ranging from 0 to 1835 pieces km-2 of seafloor, was observed. Plastic tems such as bags, bottles and fishing related debris were commonly observed across all areas. Over the entire 25-year period (1992-2017), 63% of the 2461 trawls contained at least one plastic litter item. There was no significant temporal trend in the percentage of trawls containing any or total plastic litter items across the long-term datasets. Statistically significant trends, however, were observed in specific plastic litter categories only. These trends were all positive except for a negative trend in plastic bags in the Greater North Sea - suggesting that behavioural and legislative changes could reduce the problem of marine litter within decades.

Spatial and temporal analysis of the risks posed by total petroleum hydrocarbon and trace element contaminants in coastal waters of Kuwait.

Nine trace elements including As, Cd, Cu, Fe, Hg, Ni, Pb, V and Zn, and total petroleum hydrocarbons were analysed from water samples collected from 23 stations since 1984 from Kuwaiti coastal waters. Here it was investigated whether concentrations of these determinants are at levels above Kuwaiti and internationally established assessment criteria (AC). The results indicate that Cu and Cd had the most Kuwaiti AC breaches over time. Comparing the data of the last sampled year to the least stringent international AC, then Cu and Cd showed breaches at all stations. The trends for trace metals are significantly downwards, especially for Cd and Hg. No determinant measured showed a significant upward trend, indicating that water pollution for these contaminants is not a worsening situation. However, further sampling should be carried out to confirm these findings, especially at shoreline locations, where routine monitoring ceased in 2011 to investigate any recent changes.

Determining Good Environmental Status under the Marine Strategy Framework Directive: Case study for descriptor 8 (chemical contaminants).

The European Union Marine Strategy Framework Directive (MSFD) requires individual member states to develop a robust set of tools for defining eleven qualitative descriptors of Good Environmental Status (GES), such as demonstrating that "Concentrations of contaminants are at levels not giving rise to pollution effects" (GES descriptor 8). Adopting the recommendations of the ICES/OSPAR Study Group for the Integrated Monitoring of Contaminants and Biological Effects (SGIMC), we present a case study demonstrating how the proposed approach, using chemical contaminant (metals and polycyclic aromatic hydrocarbons and polychlorinated biphenyls) and biological effects (EROD, bile metabolites and pathology) data in different matrices (sediment and biota), could be used to contribute to the determination of GES in a region of the North Sea region off the east coast of the UK.

Geographical and temporal variation of E. coli and norovirus in mussels.

Bivalve shellfish may accumulate contaminants of public health concern including pathogenic bacteria and viruses. Microbiological monitoring of production areas is based on faecal coliforms in water in the USA and Escherichia coli in bivalve molluscs in the European Union. E. coli is known to reflect contamination with Salmonella enterica but not necessarily with other human pathogens such as enteric viruses. A structured field study was undertaken at three locations in order to investigate the geographical and temporal variability of E. coli and norovirus (NoV). Total norovirus concentration differed significantly by both sampling site and sampling date. A significant correlation was found between total NoV concentration and E. coli concentration by sample, but not with E. coli in seawater. The results have implications for the establishment of sampling plans for NoV in harvesting areas and potentially also for the approach taken to classification based on faecal indicator bacteria.

Changes in the water quality conditions of Kuwait's marine waters: Long term impacts of nutrient enrichment.

This work analyses a 30 year water quality data set collated from chemical analyses of Kuwait's marine waters. Spatial patterns across six sites in Kuwait Bay and seven sites located in the Arabian Gulf are explored and discussed in terms of the changing influences associated with point and diffuse sources. Statistical modelling demonstrated significant increases for dissolved nutrients over the time period. Kuwait marine waters have been subject to inputs from urban development, untreated sewage discharges and decreasing river flow from the Shatt al-Arab River. Chlorophyll biomass showed a small but significant reduction; the high sewage content of the coastal waters from sewage discharges likely favouring the presence of smaller phytoplankton taxa. This detailed assessment of temporal data of the impacts of sewage inputs into Kuwait's coastal waters establishes an important baseline permitting future assessments to be made as sewage is upgraded, and the river continues to be extracted upstream.

Screening for contaminant hotspots in the marine environment of Kuwait using ecotoxicological and chemical screening techniques.

Kuwait is a country with low rainfall and highly concentrated industrial and domestic effluents entering its coastal waters. These can be both treated and untreated. In this study we sampled a series of coastal and open-sea sites and used a variety of analyses to identify those sites requiring the most attention. We used a high throughput GC-MS screen to look for over 1000 chemicals in the samples. Estrogen and androgen screens assessed the potential to disrupt endocrine activity. An oyster embryo development screen was used to assess biological effect potential. The chemical screen identified sites which had high numbers of identified industrial and domestic chemicals. The oyster screen showed that these sites had also caused high levels of developmental abnormalities with 100% of embryos affected at some sites. The yeast screen showed that estrogenic chemicals were present in outfalls at 2-3 ng/l E2 equivalent, and detectable even in some open water sites.

Baseline survey of marine sediments collected from the State of Kuwait: PAHs, PCBs, brominated flame retardants and metal contamination.

A geographically extensive baseline survey of sediment contamination was undertaken at twenty nine locations around Kuwait. Samples were assessed in relation to a wide range of industrial pollutants, including metals, PAHs, PCBs, PBDEs and HBCDs. The data generated indicated that levels of pollutants were generally low and below commonly applied sediment quality guidelines (SQGs). However, naturally high background concentrations of certain metals present in sediment from the region may prohibit the direct assessment against some of the routinely applied SQGs. Hot spots of contamination were identified for PAHs, PCBs and PBDEs, that were mainly associated with the Shuaiba Industrial Area, located south of the city, and known to contain a diverse mix of both light and heavy industry.

Microbial water quality and sedimentary faecal sterols as markers of sewage contamination in Kuwait.

Microbial water quality and concentrations of faecal sterols in sediment have been used to assess the degree of sewage contamination in Kuwait's marine environment. A review of microbial (faecal coliform, faecal streptococci and Escherichia coli) water quality data identified temporal and spatial sources of pollution around the coastline. Results indicated that bacterial counts regularly breach regional water quality guidelines. Sediments collected from a total of 29 sites contained detectable levels of coprostanol with values ranging from 29 to 2420 ng g(-1) (dry weight). Hot spots based on faecal sterol sediment contamination were identified in Doha Bay and Sulaibikhat Bay, which are both smaller embayments of Kuwait Bay. The ratio of epicoprostanol/coprostanol indicates that a proportion of the contamination was from raw or partially treated sewage. Sewage pollution in these areas are thought to result from illegal connections and discharges from storm drains, such as that sited at Al-Ghazali.

Histopathology and contaminant concentrations in fish from Kuwait's marine environment.

Kuwait has witnessed major socioeconomic and industrial development in recent decades. Consequently, a variety of contaminants related to these activities have been discharged directly into the marine environment. This paper describes the application of a histopathology baseline survey in two potential sentinel species, the Giant sea catfish (Arius thalassinus) and the Fourlined terapon (Pelates quadrilineatus) to assess the health of biota inhabiting Kuwait's marine environment. Histological analysis revealed several lesion types in both species, although the prevalence was generally considered low with no discernible differences between sampling locations. The analysis of contaminant burdens (metals, PCBs, PBDEs, HBCDD) in A. thalassinus, along with the analysis of bile for PAH metabolites in both species, indicated that levels of contaminant exposure was low. Overall the data show that both species appear to be susceptible to pathologies associated with environmental contaminants and therefore suitable for further investigation as sentinel organisms for biological effects monitoring.

Histopathological survey of potential biomarkers for the assessment of contaminant related biological effects in species of fish and shellfish collected from Kuwait Bay, Arabian Gulf.

The marine environment in Kuwait is dominated by Kuwait Bay, a shallow, depositional habitat vital for the breeding and propagation of marine organisms. The bay receives effluent inputs from industrial centres, ports, sewage outflows along with discharges from power and desalination plants. The major classes of pollutant discharged into the bay include petroleum hydrocarbons, metals, nutrients, cooling water and hyper-saline water. Further, the bay has been historically impacted by a deliberate release of oil and contamination with ordnance and shipwrecks during the 1991 Gulf war. With an aim to establish an integrated pollution effects monitoring programme in Kuwait, this paper describes the application of a quality assured approach to conduct a histopathology baseline survey in oriental sole (Synaptura orientalis) and the large-toothed flounder (Pseudorhombus arsius), which are two potential sentinel flatfish species present in the Arabian Gulf. Liver and gonadal histopathology revealed a range of pathologies similar to those previously observed in European and American pollution effects surveys that utilise flatfish (including pathology markers indicative of possible carcinogenesis and endocrine disruption). Further, we extended these studies to invertebrates (Jinga prawn, Metapenaeus affinis and the grooved tiger prawn, Penaeus semisulcatus) found within the Arabian Gulf. Such baseline data is essential before attempts are made to develop integrated monitoring programmes that aim to assess the health of fish and shellfish in relation to chemical contamination.

Do UK coastal and estuarine water samples pose a phototoxic threat?

Many studies have investigated phototoxicity under controlled laboratory conditions, however, few have actually demonstrated it occurring in environmental samples. Here we report on the potential for UK marine coastal waters to demonstrate phototoxicity when tested using the oyster embryo (Crassostrea gigas) bioassay in the presence UV light. Subsurface water, sea surface microlayer samples and subsurface water samples that had been extracted through solid phase extraction (SPE) columns were analysed. Results demonstrated that the majority of samples failed to display any phototoxic potential. However, those collected from Belfast Lough did display an increase in toxicity when bioassays were performed in the presence of UV light when compared to identical samples assayed in the absence of UV light. Analysis of water samples at this location identified known phototoxic PAHs, pyrene and fluoranthene. These findings suggest the need to consider the potential UV light has when determining the toxicity of environmental samples.

Histopathology of mussels (Mytilus sp.) from the Tamar estuary, UK.

This study assessed numerous histological parameters as markers of health status in mussels (Mytilus spp.) collected from several locations along a contamination gradient on the River Tamar and two coastal sites on the north and south coast of Cornwall, UK. Twenty-seven health parameters were assessed including the presence of pathogens, inflammatory lesions, non-specific pathologies and reproductive condition. Logistic regression showed that reproductive condition and inflammatory lesions showed changes indicative of a contamination gradient response. Mussel populations further upstream within the Tamar were relatively less developed compared to mussels situated downstream in the estuary. Compared to coastal locations, mussels sampled within the Tamar also exhibited a higher prevalence of inflammatory lesions that increased at locations situated furthest upstream. Similarly, levels of lipofuscin within the kidney epithelium were highest in mussels sampled within the estuary and Whitsand Bay compared to Trebarwith Strand. The most prevalent pathogens observed during this survey included Rickettsia/Chlamydia-like organisms (R/CLO), gill ciliates including Ancistrum mytili, the copepod Mytilicola intestinalis, Ciliophora-like organisms and Marteilia sp. Marteilia sp. was observed in 31% of the mussels sampled from the Cremyll Ferry site. Generally, the range and prevalence of pathogens was highest from the two estuarine locations at Cremyll Ferry and Wilcove. No significant differences were observed between estuarine sampling sites and Whitsand Bay with respect to median epithelial cell height of digestive tubules, however mussels from Trebarwith Strand did exhibit a reduced median epithelial cell height compared to mussels sampled from other sampling sites. Species genotyping was also undertaken during this study in order to consider any histological differences in relation to species. Results are discussed in relation to histopathology health parameters and biological effects monitoring.

Using biological effects tools to define Good Environmental Status under the European Union Marine Strategy Framework Directive.

The use of biological effects tools offer enormous potential to meet the challenges outlined by the European Union Marine Strategy Framework Directive (MSFD) whereby Member States are required to develop a robust set of tools for defining 11 qualitative descriptors of Good Environmental Status (GES), such as demonstrating that "Concentrations of contaminants are at levels not giving rise to pollution effects" (GES Descriptor 8). This paper discusses the combined approach of monitoring chemical contaminant levels, along side biological effect measurements relating to the effect of pollutants, for undertaking assessments of GES across European marine regions. We outline the minimum standards that biological effects tools should meet if they are to be used for defining GES in relation to Descriptor 8 and describe the current international initiatives underway to develop assessment criteria for these biological effects techniques.