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

PAHs and hopanes in the surface sediments of Qatar coast and their ecological risks: Comparison with regional and global coastal regions

The distribution, characteristics, sources and ecological risks of polycyclic aromatic hydrocarbons (PAHs) and hopanes in the surface sediments collected along the Qatar coast were investigated. Concentration of ∑14PAHs and hopanes ranged between 0.076 and 7.04 ng g-1 (mean: 2.60 ng g-1), 100 and 700 ng g-1 (mean: 205 ng g-1), respectively. Sediment samples were dominated by high molecular weight PAHs composition (4-6 rings). Diagnostic ratios of PAH concentrations showed both petrogenic and pyrogenic origins of PAHs, with a higher percentage of pyrogenic sources. The ecological risk levels of PAHs were estimated using sediment quality guidelines (SQG), mean probable effect level quotient values (PEL-Q), carcinogenic toxic equivalent quantity (TEQ), and risk quotient (RQ) evaluation methods. The calculated TEQ values (0.00012-0.85 ng g-1) were lesser than those in other locations around the globe, and were also within the safe level (600 ng g-1) suggested by the Canadian soil quality guidelines.

A preliminary study on benthic nutrient exchange across sediment-water interfaces in a shallow marine protected area of the Northwestern Arabian Gulf

Sedimentary processes are expected to play a crucial role in macronutrient cycling of the shallow Arabian Gulf. To investigate this aspect, sediment cores were collected from the shallow intertidal and subtidal expanses of the first Marine Protected Area (MPA) of Kuwait in the Northwestern Arabian Gulf (NAG). Porewater nutrient profiling and whole core incubation experiments were conducted to measure the nutrient fluxes, both with and without the addition of the nitrification inhibitor allylthiourea (ATU). The porewater data confirmed the potential of sediments to host multiple aerobic and anaerobic pathways of nutrient regeneration. The average (±SD) of net nutrient fluxes from several incubation experiments indicated that ammonium (NH4+) predominantly fluxed out of the sediment (3.81 ± 2.53 mmol m-2 d-1), followed by SiO44- (3.07 ± 1.21 mmol m-2 d-1). In contrast, the average PO43- flux was minimal, at only 0.06 ± 0.05 mmol m-2 d-1. Fluxes of NO3- (ranged from 0.07 ± 0.005 to 1.16 ± 0.35 mmol m-2 d-1) and NO2- (0.03 ± 0.003 to 0.71 ± 0.21 mmol m-2 d-1) were moderate, which either reduced or reversed in the presence of ATU (-0.001 ± 0.0001 to 0.01 ± 0.0001 mmol m-2 d-1 and -0.001 ± 0.0003 to 0.006 ± 0.001 mmol m-2 d-1 for NO3- and NO2- respectively). Thus, this study provides preliminary experimental evidence that nitrification can act as a source of NO3- and NO2- as well as contribute towards the relatively high concentrations of NO2- (>1 in the gulf waters.

Deciphering the impact of decabromodiphenyl ether (BDE-209) on benthic foraminiferal communities: Insights from Cell-Tracker Green staining and eDNA metabarcoding

This study investigates the ecotoxicological effects of BDE-209, a persistent organic pollutant (POP) prevalent in Kuwait's coastal-industrial areas, on benthic foraminiferal communities. We conducted a mesocosm experiment in which we exposed benthic foraminiferal communities sampled from the coastal-industrial areas of Kuwait to a gradient of BDE-209 concentrations (0.01 to 20 mg/kg). The impact of exposure was assessed using live-staining and metabarcoding techniques. Despite the significantly different taxonomic compositions detected by the two techniques, our results show that BDE-209 significantly affects foraminiferal communities, with moderately high concentrations leading to reduced α-diversity and considerable taxonomic shifts in both molecular and morphological assemblages. At concentrations of 10 and 20 mg/kg, no living foraminifera were detected after 8 weeks, suggesting a threshold for their survival under BDE-209 exposure. The parallel responses of molecular and morphological communities confirm the reliability of both assessment methods. This study is the first to investigate the reaction of eukaryotic communities, specifically foraminifera, to POPs such as BDE-209, generating valuable insights that have the potential to enhance field studies and aid the refinement of sediment quality guidelines.

Antibiotic Resistance Mediated by Escherichia coli in Kuwait Marine Environment as Revealed through Genomic Analysis

Antibiotic-resistance gene elements (ARGEs) such as antibiotic-resistance genes (ARGs), integrons, and plasmids are key to the spread of antimicrobial resistance (AMR) in marine environments. Kuwait's marine area is vulnerable to sewage contaminants introduced by numerous storm outlets and indiscriminate waste disposal near recreational beaches. Therefore, it has become a significant public health issue and warrants immediate investigation. Coliforms, especially Gram-negative Escherichia coli, have been regarded as significant indicators of recent fecal pollution and carriers of ARGEs. In this study, we applied a genome-based approach to identify ARGs' prevalence in E. coli isolated from mollusks and coastal water samples collected in a previous study. In addition, we investigated the plasmids and intl1 (class 1 integron) genes coupled with the ARGs, mediating their spread within the Kuwait marine area. Whole-genome sequencing (WGS) identified genes resistant to the drug classes of beta-lactams (blaCMY-150, blaCMY-42, blaCTX-M-15, blaDHA-1, blaMIR-1, blaOKP-B-15, blaOXA-1, blaOXA-48, blaTEM-1B, blaTEM-35), trimethoprim (dfrA14, dfrA15, dfrA16, dfrA1, dfrA5, dfrA7), fluroquinolone (oqxA, oqxB, qnrB38, qnrB4, qnrS1), aminoglycoside (aadA2, ant(3'')-Ia, aph(3'')-Ib, aph(3')-Ia, aph(6)-Id), fosfomycin (fosA7, fosA_6, fosA, fosB1), sulfonamide (sul1, sul2, sul3), tetracycline (tet-A, tet-B), and macrolide (mph-A). The MFS-type drug efflux gene mdf-A is also quite common in E. coli isolates (80%). The plasmid ColRNAI was also found to be prevalent in E. coli. The integron gene intI1 and gene cassettes (GC) were reported to be in 36% and 33%, respectively, of total E. coli isolates. A positive and significant (p < 0.001) correlation was observed between phenotypic AMR-intl1 (r = 0.311) and phenotypic AMR-GC (r = 0.188). These findings are useful for the surveillance of horizontal gene transfer of AMR in the marine environments of Kuwait.

Trace metal and TBT pollution in the Gulf and Oman: spatial variation and hot spots

This review assesses trace metal concentrations in nearshore and offshore bottom sediments in the Arabian Gulf and Oman focusing particularly on targeted monitoring studies of point sources of contamination near industrial zones (sometimes with ports) and desalination and power plants (often co-located). Concerns have been raised about harmful impacts from accumulation of metals in the semi-enclosed Gulf. The sediment trace metal contaminants of the greatest concern are highlighted with maximum levels of toxic trace metals such as As, Cd, Cu, Pb, Hg, Ni, Zn, and TBT recorded near port and ship repair yards/dry docks as well as industrial and power/desalination plant discharge outfalls. The levels of metals such as Cd, Pb, and Hg exceeding sediment quality guidelines at identified hot spots are of concern. Efforts to mitigate future impacts are recommended.

Baseline distribution of petroleum hydrocarbon contamination in the marine environment around the coastline of Qatar

Levels of organic contaminants (TPHs, PAHs) were simultaneously determined in both abiotic (sediments, seawater) and biotic (Pinctada radiata oysters) samples at four sites along the coastline of Qatar (Arabian Gulf) in 2017-2018. TPHs and PAHs were more frequently detected in oyster tissues than sediment and seawater samples collected from the same areas. While levels of TPHs and PAHs in seawater and sediments were lower than previous local studies and worldwide studies, PAHs levels observed in pearl oyster tissue (25.9-2240 μg/kg) were relatively higher than in previous studies in Qatar. In general, eight PAHs compounds were detected in oyster tissue, with benzo(a)pyrene displaying the highest concentration. The coast of Qatar could be affected by seasonal patterns of pollutants, where TPHs and PAHs levels increased in winter compared to summer. These results provide key information on the use of the pearl oyster as a bioindicator species and Qatar's marine environment.

Past, present and future trends of selected pesticidal and industrial POPs in Kuwait

Given the background of current global initiatives for controlling persistent organic pollutants (POPs), an overview of the scientific knowledge about the POPs issues in Kuwait is presented in this study. Both acute and chronic exposure to POPs can be associated with a wide range of deleterious health effects, including illness and death. POPs have drawn significant political and scientific interest in their fate and actions, particularly where local releases have resulted in dispersed contamination far from the source regions. These concerns inevitably led to the establishment of the Stockholm Convention (SC) on POPs. In recent years, Kuwait has carried out a wide variety of environmental research, in particular, on the monitoring of POPs in different matrices. The technological development facilitated to achieve the opposite monitoring of pesticidal and industrial POPs. The majority of these POPs are from a point source. Kuwait does not have pesticide manufacturing facilities and has not produced pesticides for POPs in the past. In the agriculture sector, Kuwait primarily imports pesticides for pest and disease control. This review encompasses the historical presence and current status of (pesticidal) organochlorine pesticides (OCPs) and (industrial POPs) PCBs and PBDEs in Kuwait based on the export, import, consumption and usage. This research also contrasts pesticide and industrial POP data from various Kuwaiti environmental matrices with data from other parts of Asia, the EU, the USA and Africa.

Benthic foraminifera as proxies for the environmental quality assessment of the Kuwait Bay (Kuwait, Arabian Gulf): Morphological and metabarcoding approaches

The rapid urbanization and industrialization of Kuwait and the consequent effluent discharges into marine environments have resulted in a degradation of water and sediment quality in the coastal marine ecosystems such as in the Kuwait Bay. This study investigates the ecological response of benthic foraminifera (protists) to environmental stress in the Kuwait Bay. The traditional morphological approach was compared to the innovative environmental DNA (eDNA) metabarcoding to evaluate the ecological quality status (EcoQS). Forty-six surface sediment samples were collected from selected stations in the Kuwait Bay. To detect the pollution gradient, environmental parameters from water (e.g., salinity, pH, dissolved oxygen) and sediment (e.g., grain-size, trace metals, total organic carbon, total petroleum hydrocarbons) were measured at each station. Although the foraminiferal assemblages were different in the morphological and molecular datasets, the species turnover was congruent and statistically significant. Diversity-based biotic indices derived from both morphological and metabarcoding approaches, reflect the environmental stress gradient (i.e., organic and metal contaminations) in the Kuwait Bay. The lowest values of EcoQS (i.e., bad to poor) are found in the innermost part (i.e., Sulaibikhat Bay and Ras Kazmah), while higher EcoQS values occur in the outer part of the bay. This study constitutes the first attempt to apply the foraminiferal metabarcoding to assess the EcoQS within the Arabian Gulf and presents its advantages compared to the conventional morphological approach.

Antibiotic Resistance Genes Associated with Marine Surface Sediments: A Baseline from the Shores of Kuwait

Marine sediments are a sink for antibiotic resistance genes (ARGs) and antibiotic-resistant microbes (ARMs). Wastewater discharge into the aquatic environment is the dominant pathway for pharmaceuticals reaching aquatic organisms. Hence, the characterization of ARGs is a priority research area. This baseline study reports the presence of ARGs in 12 coastal sediment samples covering the urban coastline of Kuwait through whole-genome metagenomic sequencing. The presence of 402 antibiotic resistance genes (ARGs) were recorded in these samples; the most prevalent were patA, adeF, ErmE, ErmF, TaeA, tetX, mphD, bcrC, srmB, mtrD, baeS, Erm30, vanTE, VIM-7, AcrF, ANT4-1a, tet33, adeB, efmA, and rpsL, which showed resistance against 34 drug classes. Maximum resistance was detected against the beta-lactams (cephalosporins and penam), and 46% of genes originated from the phylum Proteobacteria. Low abundances of ESKAPEE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumonia, Acinetobacter baumanii, Pseudomonas aeruginosa, Enterobacter sps., and Escherichia coli) were also recorded. Approximately 42% of ARGs exhibited multiple drug resistance. All the ARGs exhibited spatial variations. The major mode of action was antibiotic efflux, followed by antibiotic inactivation, antibiotic target alteration, antibiotic target protection, and antibiotic target replacement. Our findings supported the occurrence of ARGs in coastal marine sediments and the possibility of their dissemination to surrounding ecosystems.

Methylmercury, Trace Metals, Organotins and Their Effects on the Qatari Mangrove Shrimp, Palaemon khori

The Qatari mangroves of Al-Khor are being increasingly exposed to a wide variety of anthropogenic pollutants due to land reclamation and urban expansion. In this study, we evaluated the lethal and genotoxic effects of methylmercury, trace metals, and organotins, assessing mortality and aneuploidy levels (abnormal number of chromosomes) in the endemic shrimp Palaemon khori under laboratory conditions. In the experimental design, two different concentrations were used for each family of contaminant (single or combined): an environmental concentration equivalent to the maximum value reported in the environment and a value ten times higher, for a period of eight weeks. Survival decreased significantly when pollutants were administrated in combination, even at environmental concentrations (as shown by Cox proportional hazards ratios): similar levels of mortality would be reached by individual type of pollutants only at ten times the environmental concentration. This critical result, under controlled lab conditions, highlights the importance of monitoring mixtures of contaminant types over single ones in the marine environment. Aneuploidy was reported in all treatments and control ranging from 5% to 19% at week four and from 7% to 21% at week eight. All treatments presented significantly higher aneuploidy levels when compared to the control. However, no significant difference was observed between the two time periods, even though 30% of the treatments could not be assessed at week eight, as not enough animals were still alive. In conclusion, the use of endemic species should be considered a valuable tool to determine local perturbations, representing a regional bioindicator of multiple environmental stressors from the initial stages of contamination.

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.

Temporal trend of polychlorinated biphenyls contamination in the northwestern Arabian Gulf - Evidence from sediment records

This study provides an insight into the polychlorinated biphenyls (PCBs) inventories in the sediments of the northwestern Arabian/Persian Gulf. PCBs can be used as chemical markers that correlate with historical events in the region, to estimate the sedimentation rates in the northern Gulf, and to determine the sources of pollutants in the study area. The concentrations of PCBs were generally patchy in sediments. At Station 1 the ΣPCB concentrations generally fluctuated between 0.100 and 0.400 ng g^-1 dw throughout the depositional history measured in a sediment core. There were four peaks in the ΣPCB profile corresponding to 1969, 1979, 1983 and 1991. Station 2 showed a prominent peak at depth of 25 cm. The concentrations of the ΣPCBs and ΣICE congeners at this depth were 28 and 12 ng g^-1 dw respectively. Concentrations then dropped dramatically thereafter by a factor of 4. The ΣPCB concentrations at Station 3 were very low compared to the concentrations measured at Stations 1 and 2. The PCB concentration in Core 4 which was taken from open waters was 2-3 orders of magnitude lower than those in the other coastal cores. However, a 1990-91 peak was omnipresent in these cores. There is no record of PCB production within the Gulf region, and PCB releases into the Kuwait marine environment are likely to originate from their use in products. These maxima in early-1990s can be correlated to inputs from war-related activities, including the reported destruction of PCB-containing transformers and military equipment during the occupation of Kuwait. None of the recent sediment core sections at the four stations had a ΣPCB concentration near the effects range-median (ERM) concentration of 180 ng g^-1, or permissible exposure limits (PEL) of 189 ng g^-1, or were above the effect range-low (ERL) values of 22.7 ng g^-1.

Petroleum hydrocarbon pollution in sediments from the Gulf and Omani waters: Status and review

This review presents the spatio-temporal distribution of petroleum hydrocarbons including total petroleum hydrocarbon (TPH), total organic carbon (TOC), total aliphatics, unresolved complex mixture (UCM), polycyclic aromatic hydrocarbons (PAHs), and total aromatic hydrocarbons in marine sediments of the Gulf (Iraq, Iran, Kuwait, Saudi Arabia, Bahrain, Qatar, United Arab Emirates and Oman). The TPH ranged between 0.134 and 48,018 μg g^-1 dw where 10-15 μg g^-1 dw was considered as a background concentration. The TOC levels were between 0.04 and 14.96% with a mean concentration of 1.154 ± 0.523%. Total aliphatic hydrocarbon levels were reported between 0.1 and 76 μg g^-1, the 2005 levels that had the largest spatial coverage were between 0.1 and 4.4 μg g^-1. The unresolved complex mixture was very variable post Gulf War but by 2005 most of the Gulf War artifacts had decreased and the levels were between 1.5 and 73.5 μg g^-1. The ƩPAHs in bottom sediments by 2005 were between 0.3 and 3450 ng g^-1. The total aromatics were limited in spatial extent and varied between 1.0 and 14,000 μg g^-1. Most of the locations with elevated contamination levels were near point sources, e.g. oil facilities and ports, and these sites could be categorized as chronically contaminated by oil. This review highlights the paucity of the data both in terms of the spatial extent and temporal coverage, and with several Gulf states undergoing large-scale coastal developments and offshore oil exploration, it will be prudent to undertake regular monitoring of the petroleum hydrocarbons to ensure effective ecosystem functioning as well as seafood and drinking water safety in the Gulf region. The spatial distribution also highlights the lack of uniformity in assessments and the need to support marine pollution assessments in the Gulf countries.

Multi-matrix distribution and contamination profiles of HBCDD isomers in a man-made saltwater lake near industrial complexes with high flame retardant consumption in Korea

South Korea is one of the largest consumers of flame-retardants worldwide. In this study, water, sediment, and biota samples were collected from a highly industrialized lake to investigate contamination, isomeric profiles, source, and the bioaccumulation potential of hexabromocyclododecanes (HBCDDs). Almost all of the sediments were severely contaminated by HBCDDs, which were some of the highest global levels compared to those found in previous studies. The highest concentrations and similar profiles to those of technical mixtures of HBCDDs were observed in creeks passing through industrial complexes, indicating on-going contamination by high consumption of HBCDDs from industrial activities. γ-HBCDD was dominant in water and sediment, whereas α-HBCDD was dominant in fish and shellfish. The diastereoisomeric profiles of HBCDDs in multiple matrices were influenced by proximity to industry and chemical properties. In-situ biota-sediment accumulation factors of α-HBCDDs were > 1 in benthic species, implying that HBCDDs are of great concern in sedimentary environments.

Depositional time trends of phosphorous accumulation in a dated sediment core from the northwestern Arabian Gulf: Can phosphorous be used to support 210Pb chronologies in coastal aquatic sediments?

The use of ²¹⁰Pb dating for the reconstruction of contaminant profiles in undisturbed sediments is the most widely acceptable technique historically. Due to the uncertainties associated with the technique, dating of sediments have often been supported by ancillary evidence such as an alternative historical marker in the catchment that is preserved in the sedimentary records. The most widely used verification marker is ¹³⁷Cs, which is attributed to global fallout from past nuclear weapons testing, and the Chernobyl accident. In the southern hemisphere, and the mid-latitudes, the ¹³⁷Cs signal from Chernobyl fallout is often absent from the sedimentary records making it very difficult to verify the ²¹⁰Pb chronologies in these natural archives. This study reports the spatial and temporal variability of total phosphorus (TP) and its forms in sediments from Kuwait Bay and provides evidence of the possibility of using Phosphorous as a potential marker to support dates derived from ²¹⁰Pb dating. In the current study we report the spatial and temporal variations in the concentrations of Phosphorus from near-shore sediments from Kuwait. The mean (and range) of TP concentration in surficial sediments is 19.4 (12.2 to 24) μmol-P g^-1 dry weight. The highest concentrations were measured in the deepest portions of the Bay which is characterized by fine grained sediments. The vertical profile of TP in the sediments was characterized by a gradual increase in concentration from lower layers to a subsurface maximum (at approximately 4-5 cm) followed by an exponential decrease to the sediment-water interface. The sedimentary TP profile correlated remarkably well with changes in the population of Kuwait over the last three decades, suggesting that wastewater inputs into the Bay from treatment plants are an important source of phosphorus in the coastal waters. The decrease in concentration in sediment deposited over the last five years of the core is explained by the commissioning of an improved wastewater treatment plant with higher phosphorus removal efficiency. These fluctuations preserved in the sedimentary records linked to identifiable historical events provides powerful evidence that this nutrient associated with wastewater inputs in coastal aquatic environments can be used as ancillary information to support ²¹⁰Pb dating.

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.

Occurrence of polychlorinated biphenyl congeners in marine sediment of Makran region, Chabahr bay, Iran

In this study, selected PCB congeners (IUPAC numbers 28, 52, 101, 138, 153, and 180) were quantified in 34 stations of Chabahr bay and around it in the Makran region of Iran. The sum of total PCB concentrations varied from below the detection limit to 485 ng kg^-1 dry weight of sediment. Based on the Canadian Sediment Quality Guidelines, the effect of detected PCBs was negligible for aquatic organisms. According to the dominance of PCB 28 and 52 with average range of 62 to 100% of total PCBs, maritime transportation and atmospheric deposition appear to be the important source of PCBs in this region. Further, the presence of components of commercial products such as ClophenA50 appears to be one of the probable sources.

Grimontia sedimenti sp. nov., isolated from benthic sediments near coral reefs south of Kuwait

A Gram-stain-negative, rod and rod-curved shaped motile bacterium designated strain S25^T was obtained from benthic sediment collected near the Kubbar Island coral reefs south of Kuwait. Phenotypic analysis revealed that strain S25^T was slightly halophilic, mesophilic and facultative anaerobic, fermenting d-glucose, d-ribose, d-mannose, d-mannitol, maltose, fructose, gentiobiose, cellobiose, melibiose, trehalose and sucrose. It was positive for oxidase and indole production and negative for arginine dihydrolase and lysine and ornithine decarboxylases. It contained C_16 : 1  ω7c/C_16 : 1  ω6c (summed feature 3), C_18 : 1 ω7c (summed feature 8) and C_16 : 0 as the major fatty acids. Strain S25^T grew optimally at 30 °C and pH 8 in the presence of 3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA sequences revealed that strain S25^T is related to species of the genus Grimontia, having 99.15 % similarity to 'Grimontia indica' AK16^T, 99.08 % to Grimontia celer 96-237^T and 98.66 % to Grimontia marina IMCC 5001^T. The DNA G+C content was 48.8 mol% and the full genome analysis for the strain S25^T showed that the bacterium has a genome size of 5 158 621 bp and contains 4730 predicted protein-encoding genes. The average nucleotide identity values between the S25^T genome and the genomes of its nearest matches ranged between 81.39 and 94.16 %. The strain was distinguishable from the phylogenetically related genera through differences in several phenotypic properties. On the basis of the phenotypic, phylogenetic and genetic data, strain S25^T represents a novel species in the genus Grimontia, for which the name Grimontia sedimenti sp. nov. is proposed. The type strain of Grimontia sedimenti is S25^T (=DSM 28878^T=LMG 28315^T).

An overview of persistent organic pollutants along the coastal environment of Kuwait

The oil discovery in the Arab Gulf, and particularly in Kuwait, has led to rapid urbanization, population development, industrialization, and, with it, many problems of oil and nonoil pollution. The rapid growth of the manufacturing sector in Kuwait occurred mainly along its coastal margins. Natural oil sequestration areas have been established and are deemed as critical point pollution sources at different locations along the coast. This has allowed the release of a variety of toxins directly into the marine ecosystem, including petroleum hydrocarbons. The ecotoxicological effects of persistent organic pollutants (POPs) in the aquatic environment have been causing a significant concern. Much work concentrated primarily on hydrocarbon emissions from petroleum/combustion, with few papers authenticating other target POPs (PCBs, PBDEs, and dioxins). This study aims to reflect past ideas on the production and sources of POPs in the marine environment in Kuwait and their comparison with worldwide outcomes. Much of the literature reviewed reported that while Kuwait’s aquatic ecosystem has been exposed to a wide variety of incidents of pollution, overall emission rates remain relatively low. Nonetheless, soil pollution hotspots are also associated with point sources of chemical waste, such as those from the Shuaiba industrial area, in a variety of areas along the coast.

Insights into the development of hepatocellular fibrillar inclusions in European flounder (Platichthys flesus) from UK estuaries

Hepatocellular fibrillar inclusions (HFI) are an unusual pathology of unknown aetiology affecting European flounder (Platichthys flesus), particularly from estuaries historically impacted by pollution. This study demonstrated that the HFI prevalence range was 6-77% at several UK estuaries, with Spearman rank correlation analysis showing a correlation between HFI prevalence and sediment concentrations of ∑PBDEs and ∑HBCDs. The data showed that males exhibit higher HFI prevalence than females, with severity being more pronounced in estuaries exhibiting higher prevalence. HFI were not age associated indicating a subacute condition. Electron microscopy confirmed that HFI were modified proliferating rough endoplasmic reticulum (RER), whilst immunohistochemistry provided evidence of VTG production in HFI of male P. flesus. Despite positive labelling of aberrant VTG production, we could not provide additional evidence of xenoestrogen exposure. Gene transcripts (VTG/CHR) and plasma VTG concentrations (>1 μg ml^-1), were only considered elevated in four male fish showing no correlation with HFI severity. Further analysis revealed that reproductively mature female P. flesus i.e. >3-year-old, did not exhibit HFI, whereas males of all ages were affected. This, combined with previous reports that estradiol (E2) can impair mixed function oxygenase activity, supports a hypothesis that harmful chemical metabolites (following phase 1 metabolism of their parent compounds) are potentially responsible for HFIs observed in male and ≤ 3-year-old female fish. Consequently, HFI and xenoestrogenic induced VTG production could be independent of each other resulting from different concurrent toxicopathic mechanisms, although laboratory exposures will likely be the only way to determine the true aetiology of HFI.

An assessment of microplastics threat to the marine environment: A short review in context of the Arabian/Persian Gulf

Microplastics are recognised as a (persistent) pollutant and are believed to be ubiquitous in the marine environment. The importance of this issue is evident from the large number of technical publications and research efforts within the past decade. However, the Arabian (Persian) Gulf region has few reported datasets in spite of being an area with excessive plastic use and a hefty generation rate of plastic solid waste. This communication aims at stimulating a discussion on this topic focusing on the available regional and international datasets, along with the environmental conditions that are likely to contribute to the disintegration and transport of the plastic debris rendering it as microplastic. This work also highlights some of the constraints in sampling techniques, identification methods, and the reported units of microplastics. Most studies employ neuston nets of variable dimensions that samples different thicknesses of surface water, which also posses a major constraint in standardising field sample collection. Extrapolation of a trawl to units such as particles.km^-2 without considering the fact that neuston nets collect three-dimensional samples, is also another aspect discussed in this communication. This study also intends to initiate a discussion on standardising the practices across the region to enable an intercomparison of the reported data. In addition, it calls for a comprehensive assessment using the standardized methodology for putting a mitigation plan for microplastics as a potential threat detected in environmental sinks.

Heavy metals and persistent organic pollutants contamination in river, estuary, and marine sediments from Atlantic Coast of Democratic Republic of the Congo

The pollution assessment and the evaluation of potential risks in the Atlantic Coastal Region of the Democratic Republic of the Congo are still very limited. Consequently, the present study investigates for the first time the concentrations of heavy metals and persistent organic pollutants (organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs)) in river, estuary, and marine sediments from this area. The results highlighted high concentrations of Cr, Zn, As, and Pb exceeding the probable effect level (PEL) on aquatic life. Zn was the most dominant element detected at a range of 180-480 mg kg^-1 in marine sediment, 132-382 mg kg^-1 in estuary sediment, and 121-687 mg kg^-1 in river sediment. Total PCBs (∑7 × 4.3) ranged from 1995 to 20,156 μg kg^-1, 2013-12,058 μg kg^-1, and 1861-36,417 μg kg^-1 in marine, estuary, and river sediments, respectively. Total PCBs (∑7 × 4.3) were above PEL for all sediments, suggesting potential adverse effects on benthic organisms. The OCP, PBDE, and PAH levels were low to moderate for all sediments. Taking into consideration, the concentrations of Zn, Pb, PCBs, and DDTs, probable environmental risks, are present.

A new perspective on marine assessment of metals and organic pollutants: A case study from Bay of Santander

Pollution assessment is worldwide generally performed based on 'Trend assessment' or 'Status assessment´, and usually requires monitoring programs that should be designed in terms of pollutants to be studied, frequency and locations. Five groups of pollutants: polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and trace metals, were selected to evaluate how actual monitoring programs are coping with the evaluation of anthropogenic activities affect the environment and whether use restrictions and laws that ban certain pollutants are being effective. Santander Bay, in Northern Spain, is an industrial area with 250,000 inhabitants and with several rivers discharging into the Bay; those characteristics made the area an adequate location to perform the study. Marine sediment was selected as the study matrix since it gives comprehensive information regarding the human activities in coastal areas. The study clearly shows that there can be some potential biological impacts on the marine environment due to PAHs (mainly BghiP), PCBs (mainly congener CB118) and metals. On the other hand all analysed OCPs and PBDEs presented values below the applicable guidelines and will therefore, in principle, not give rise to environmental problems. Consequently, even after decades of banning and use restrictions, the studied pollutants are still a main issue in coastal areas. Moreover, the present study helps in the definition of future monitoring programs providing a complete description about the current situation of the listed pollutants.

Size Scaling of Contaminant Trace Metal Accumulation in the Infaunal Marine Clam Amiantis umbonella

Size scaling of the accumulation of four trace metals was examined in the infaunal clam Amiantis umbonella in Kuwait Bay. In clams of varying shell length (2.5-5 cm), soft tissue growth in A. umbonella from a contaminated site was inhibited compared with clams from a less contaminated reference site. Body burdens of all four metals were positively correlated with clam soft tissue wet weight, but for Cd, Cu, and Pb, correlations were stronger in clams from the contaminated site (r² = 0.6-0.9, p < 0.001) than the reference site (r² = 0.2-0.3, p < 0.002). Scaling factors for the accumulation of Cd, Cu, and Pb in the soft tissues of A. umbonella from both sites were not significantly different than 1, indicating that clams accumulated these metals in proportion to growth with little regulation. The scaling factor of Hg in clams from the contaminated site also was 1 but was 0.5 and 2.4 for high and low Hg accumulating subpopulations of clams from the reference site, respectively. The greater retention of Hg with respect to growth in clams from the reference site than from the contaminated site requires further investigation to determine differences in Hg bioavailability at the two sites and the form of Hg these clams accumulate.

A baseline investigation of benthic foraminifera in relation to marine sediments parameters in western parts of the Arabian Gulf

This baseline paper discusses the distribution and abundance of living benthic foraminifera in relation to Potentially Toxic Elements (PTEs) such as As, Al, Fe Cd, Co, Cr, Cu, V, Ni, Hg, Pb, and Zn in marine sediments collected from 30 stations in the offshore Arabian Gulf to define baseline environmental conditions for the implementation of future biomonitoring programs. A total of 271 living benthic foraminiferal species were identified belonging to 66 genera, 37 families and 6 orders. Data from this work suggest that PTEs are within the range of background values, and the sediments support highly diversified and stable benthic foraminiferal communities adapted to the unique environmental conditions in the Gulf. Thus, the effect of anthropogenic activities is deemed negligible. This study is expected to provide a baseline dataset for PTE levels in sediment, benthic foraminiferal communities, and identify endemic species adapted to extremes of temperature and saline conditions typical of the Gulf.

Occurrence and bioaccumulation of persistent toxic substances in sediments and biota from intertidal zone of Abu Ali Island, Arabian Gulf

North Abu Ali Island is contaminated by crude oil from exogenous sources with a variety of persistent toxic substances (PTSs) being input into intertidal sediments. We detected an array of PTSs in sediments and benthic biota off north Abu Ali Island (Arabian Gulf), including 35 polycyclic aromatic hydrocarbons (PAHs), 6 alkylphenols (APEOs), 10 styrene oligomers (SOs), and tributyltin. The PTS concentrations were generally greater than those reported in other areas of Arabian Gulf. PAHs mainly originated from petrogenic sources, and APEOs and SOs seem to be of recent origin. Field-based biota-sediment accumulation factors (BSAF) varied by taxa and compounds, but clearly depended on the log K_ow values of individual compounds. Some PTSs exceeded the established guidelines for sediments and biota; we found particularly great BSAFs for alkyl-naphthalenes (C1- and C2-), nonylphenol monoethoxylates, and 2,4,6-triphenyl-1-hexene. Remediation will require on-site clean-up of toxic chemicals together with immediate efforts on preventing input of current pollution sources in the given area.

Source apportionment and seasonal cancer risk of polycyclic aromatic hydrocarbons of sediments in a multi-use coastal environment containing a Ramsar wetland, for a Caribbean island

Although polycyclic aromatic hydrocarbons (PAHs) are toxic pollutants for which some are known carcinogens, there is limited information on the cancer risk such substances pose to the population via marine sediments, despite a significant part of the world's food supply being derived from the coastal environment. This study was conducted in a heavily industrialized and urbanized coastal area, in Trinidad. PAHs were quantified in sediments during the dry and wet seasons and were observed to be significantly higher in the wet season compared to the dry season. Also emerging from this study is that PAH levels were lower, in the areas where natural gas is the dominant energy source for industries, compared with those areas where crude oil-based fossil fuel is predominantly used. Perylene levels were demonstrated to be of biogenic origin near the protected wetland area. It was observed that nearshore sediment PAHs concentrations were higher than offshore levels. The sources of PAHs, identified by Positive Matrix Factorization (PMF) in the marine sediments, were vehicular combustion of gasoline and diesel, biomass burning, industrial combustion and oil spills. The mean Incremental Lifetime Cancer Risks (ILCR) due to fish consumption from this region during the dry and wet seasons was >1 × 10^-4, indicating a high cancer risk to the human population. The annual non-cancer risk (HQ) was high >1 at the 90th percentile level with an adverse risk to about 14% of the population. These results can be utilized for developing an effective environmental management policy for coastal areas in Trinidad and the wider Caribbean region, given that much of the islands' populations depend on the coastal regions for seafood. In addition, these results may assist in boosting current efforts of policymakers, towards phasing out crude oil-based fossil fuels for cleaner energy sources, such as compressed natural gas.

Cytotoxicity of organic and inorganic compounds to primary cell cultures established from internal tissues of Chelonia mydas

Chemical contaminants have been found in the tissues of sea turtles from all over the world; however, very little is known about the effects. Recently, in vitro alternatives to live animal testing have been applied to sea turtles due to their ethical and practical benefits. While primary skin fibroblasts have been established for several species of sea turtle, cells from internal organs are lacking, though they may be more relevant due to the well documented accumulation of contaminants within internal tissues. This study established primary cell cultures from the small intestine, heart, liver, ovary and skin of green turtles (Chelonia mydas). Cells were exposed to ten contaminants typically found in sea turtles to examine potential variations in sensitivity among cells established from different organs. Differences between cells established from different animals were also examined, including a comparison of cells established from a turtle with fibropapillomatosis (FP) and healthy turtles. Loggerhead (Caretta caretta) primary skin cells were also included for species comparisons. Significant differences were found between the organ types, with liver and heart being the least sensitive, and skin being the most sensitive. Overall, variation between the organ types was low. Primary skin fibroblasts may be a suitable and representative cell type for in vitro turtle toxicology research, as it is relatively easy to obtain from healthy live animals. Skin cultures provide a more sensitive indication of effect, and could be used as an early warning of the potential effects of chemical contamination. Some species differences were found but no differences were found between cell cultures from an FP turtle and healthy turtles. When EC₅₀ values were compared to accumulation values from the literature, inorganic contaminants, such as Zn, Cd, Cr, Hg, and Cu were identified as posing a potential risk to sea turtle populations around the world.

Antimicrobial resistance in the Gulf Cooperation Council region: A proposed framework to assess threats, impacts and mitigation measures associated with AMR in the marine and aquatic environment

It is becoming increasingly clear that the genetic diversity and abundance of antimicrobial resistance (AMR) in non-clinical settings has been underestimated and that the environment plays an integral role in enabling the development of AMR. Due to specific demographic and environmental factors the Gulf Cooperation Council (GCC) region may be particularly susceptible to the threat of AMR, with the marine and aquatic environment potentially playing a specific role in its development and propagation. The demographic factors include rapid population growth, significant international population movements, heavy antibiotic use and insufficient antibiotic stewardship. Environmental factors leading to susceptibility include notable inputs of untreated sewage effluent, high ambient water temperatures, elevated concentrations of heavy metals, and poorly regulated use of antimicrobials in veterinary settings. However, to date there is only a limited understanding of the role that this environment plays in enabling the emergence and propagation AMR in this region. This article provides an overview of the risk associated with AMR in the marine and aquatic environment in the GCC region and proposes a framework for understanding how such environments interact with the wider development and propagation of resistance. It identifies priority actions aligned with the World Health Organisation AMR Global Action Plan and associated national action plans to evaluate the role of marine and aquatic systems relative to the wider factors driving AMR emergence and propagation. The proposed framework and actions to evaluate the role of marine and aquatic environments in driving propagation and emergence of AMR are equally applicable at the regional and national level beyond the GCC.

Brominated Flame Retardants in Sediments of Four Coastal Lagoons of Yucatan, Mexico

We examined the sediments of four coastal lagoons (Ria Lagartos, Bocas de Dzilam, Laguna de Chelem and Ria Celestun) from the state of Yucatan, Mexico, for three widely used commercial polybrominated diphenyl ethers formulations (penta-, octa- and deca-BDE). The most commonly found congeners in all four lagoons were BDEs 47, 99 and 100 (all in the penta-BDE formulation) and BDE209 (deca-BDE formulation). The greatest variety and highest concentrations of brominated flame retardants were found in Ria Lagartos, which also showed the highest BDE 100 concentration (24.129 ng/g). Hexabromocyclododecane was found in all lagoons, but at lower concentrations than those of the various polybrominated diphenyl ethers. Dispersal routes of these compounds are discussed, such as a ring of sinkholes (cenotes) adjacent to the lagoons. Moreover, electronic waste is a serious problem because municipal landfills have been the primary disposal method for these wastes and therefore represent a reservoir of brominated fire retardants.

Biomarkers in fish as a measure of the state of marine environment of Kuwait

The health of a marine ecosystem can effectively be monitored by studying the levels of biomarkers in a representative species. A change in background level of a biomarker indicates exposure to a specific type of pollutants. It also identifies bioavailability and the organism response to the causative agent among the compounds present in the surrounding water body. Yellowfin seabream (Acanthopagrus latus), a local variety of fish, was examined for parent PAHs in the liver, its metabolites in bile by the GC-MS method as exposure biomarkers and cytochrome P4501A1 by assay of ethoxyresorufin-o-deethylase (EROD) in the liver as an effect biomarker. A comparison was made between fish collected in 2015 with the fish collected in 2005-2006 and stored at - 80 °C in the fish bank. The objective was to examine the extent of changes in the environmental quality of the Kuwait marine area and the status of fish health concerning oil-related pollutants since Arabian Gulf is surrounded by oil-producing countries. Interestingly, insignificant differences between the liver PAH content and EROD activity were observed in fish over the sampling periods. The fish efficiently metabolized PAHs and excreted hydroxy-metabolites in bile. The study suggested that environmental quality of the Kuwait marine area was not deteriorated to any serious extent in the last decade and biomarkers can be used effectively in assessing the thrust of sub-optimal levels of various contaminants present in the marine area on the resident biota.

Environmental characterization of a semiarid hyper saline system based on dissolved trace metal-macronutrient synergy: A multivariate spatio-temporal approach

Trace metals and macronutrients play key roles in marine biogeochemical processes. Despite their higher availability, no reliable information is available on their ecological role in the hypersaline waters of NW Arabian Gulf. The present study identifies their synergistic effect on environmental characteristics and autotrophic biomass in the shallow coastal and offshore waters, off Kuwait on a seasonal basis. Surface water samples collected along four predefined transects were analyzed for physico-chemical and biological variables during summer (n=27) and winter (n=27) seasons. Multivariate analyses revealed clear spatial and seasonal trends, and identified the best suit of environmental variables responsible for the seasonal variability in phytoplankton biomass. Using statistically derived supply to demand ratios, carbon-trace metal stoichiometry, and bioavailability of trace metals, we propose possible growth regulating factors for phytoplankton on a seasonal basis in the NW Arabian Gulf, off Kuwait. This is the first report on trace metals from the entire Arabian Gulf, using clean techniques and multivariate statistical approach.

Pollutants in Plastics within the North Pacific Subtropical Gyre

Here we report concentrations of pollutants in floating plastics from the North Pacific accumulation zone (NPAC). We compared chemical concentrations in plastics of different types and sizes, assessed ocean plastic potential risks using sediment quality criteria, and discussed the implications of our findings for bioaccumulation. Our results suggest that at least a fraction of the NPAC plastics is not in equilibrium with the surrounding seawater. For instance, "hard plastic" samples had significantly higher PBDE concentrations than "nets and ropes" samples, and 29% of them had PBDE composition similar to a widely used flame-retardant mixture. Our findings indicate that NPAC plastics may pose a chemical risk to organisms as 84% of the samples had at least one chemical exceeding sediment threshold effect levels. Furthermore, our surface trawls collected more plastic than biomass (180 times on average), indicating that some NPAC organisms feeding upon floating particles may have plastic as a major component of their diets. If gradients for pollutant transfer from NPAC plastic to predators exist (as indicated by our fugacity ratio calculations), plastics may play a role in transferring chemicals to certain marine organisms.

Baseline concentrations and distributions of Polycyclic Aromatic Hydrocarbons in surface sediments from the Qatar marine environment

Coastal sediments in marine waters of Qatar have the potential of being contaminated by Polycyclic Aromatic Hydrocarbons (PAHs) due to extensive petroleum exploration and transportation activities within Qatar's Marine Exclusive Economic Zone. In this study, the concentration and distribution of sixteen PAHs classed as USEPA priority pollutants were measured in sediments from the eastern Qatari coast. PAHs were recovered from sediments via accelerated solvent extraction and then analyzed using Gas Chromatography-Mass Spectrometry. Total concentrations of the PAHs were in the range of 3.15-14.35μg/kg, and the spatial distribution of PAHs is evaluated in the context of sediment total organic content, depth and the grain size together with and the proximity of petroleum exploration and transportation activities. The data show that the concentrations of PAHs within the study area were in the low-range, suggesting a low risk to marine organisms and limited transfer of PAHs into the food web.

Brominated flame retardants in marine environment focused on aquaculture area: Occurrence, source and bioaccumulation

Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA), and hexabromocyclododecanes (HBCDs), were investigated in bivalve (i.e., oyster (Crassostrea gigas) and mussel (Mytilus coruscus)), sediment, and seawater samples collected from aquaculture areas in South Korea to identify their occurrence, sources, and bioaccumulation. Among the studied chemicals, HBCDs predominated in bivalves and sediment, with concentrations of ND-67.52ng/g lipid weight and 3.47-168ng/g dry weight, respectively, while TBBPA was the highest contributor in seawater (ND-2.79ng/L). Compared with a non-aquaculture area, HBCD and PBDE concentrations were significantly higher in all matrices in the aquaculture area (Mann-Whitney U test, p<0.05), suggesting that sources may be located near or associated with the aquaculture areas, such as industrial complexes and expanded polystyrene buoys. Finally, the bioconcentration factor (BCF) and biota-sediment accumulation factor (BSAF) were estimated. Among the studied BFRs, BDE-47 (BCF: 1.70×10⁶L/kg; BSAF: 20.92) and α-HBCD (BCF: 1.05×10⁶L/kg; BSAF: 0.13) showed the highest accumulation potentials in bivalves.

Assessment of heavy metal and petroleum hydrocarbon contamination in the Sultanate of Oman with emphasis on harbours, marinas, terminals and ports

The assessment here includes data on levels of contaminants (petroleum hydrocarbons and heavy metals) in sediments and biomonitor organisms, including the eulittoral rock oyster Saccostrea cucullata and subtidal biomonitors, the barnacle Balanus trigonus and the antipatharian coral Antipathes sp., at harbours, marinas, terminals and large ports along the coastline of Oman. TBT levels in harbour and port sediments up to a maximum of 100ppb TBT dry weight are highlighted. Oysters contained concentrations up to 367ppm mg TPH/kg dry weight. The maximum levels of Cd, Cu, Pb and Zn were found in the subtidal sediments and barnacles at the oil tanker loading Single Buoy Mooring stations in Mina Al Fahal. In general, the levels of most of the contaminants analysed are at low to moderate concentrations compared to those in highly contaminated sites such as shipyards and dry docks, but continued monitoring is recommended especially during any dredging campaigns.

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.

Sources and levels of endocrine disrupting compounds (EDCs) in Kuwait's coastal areas

The sources and levels of endocrine disrupting compounds in Kuwait's coastal areas were investigated. Phthalates, alkylphenols and estrogens were measured in the inflows and outflows of three sewage treatment plants as well as in the seawater and sediments from the sewage impacted coastal areas. Phthalate levels in the inflow of the treatment plants ranged from 8.9 to 78.3μg/l; alkylphenols from 0.7 to 279ng/l and estrogens from 30 to 368ng/l. On average, the treatment plants removed about 80% of these compounds. The outflows, however, contained significant levels of all three classes of compounds. The seawater from the sewage impacted area also contained detectable levels of these compounds. Sediment samples from these locations contained elevated levels of phthalates (ranging from 2145 to 15,722μg/kg) and lower levels of alkylphenols (ranging from 2.49 to 15.14μg/kg) and estrogens (ranging from 4.1 to 214μg/kg, dry wt.).

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.

Tracking polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in sediments and soils from the southwest of Buenos Aires Province, Argentina (South eastern part of the GRULAC region)

PCBs and PBDEs (7 and 10 congeners, respectively) were analyzed in four coastal surface sediments collected from the northern shore of Bahía Blanca estuary and in nine soils from different locations of Bahía Blanca city and the surrounding region (Southwest of Buenos Aires Province, Argentina). Sediment samples showed PCBs_(Σ7) concentrations ranged from 0.61 to 17.6ngg^-1 (dry weight=dw) and PBDEs_(Σ10) from 0.16 to 2.02ngg^-1 dw, whereas in soil samples ranged from 0.04 to 1.67ngg^-1 dw for PCBs_(Σ7) and 0.04 to 10.7ngg^-1 dw for PBDEs_(Σ10). The highest concentrations of both chemicals were detected in the urban and industrial/port areas showing a dominance of the higher chlorinated PCB congeners: in sediments for PCB-180 (56±33%) and PCB-153 (11±6%); and in soils for PCB-138 (23±3%), PCB-153 (22±2%) and PCB-180 (18±7%). In contrast, lower chlorinated PCB congeners were predominant at more distant sites; in sediments for congeners PCB-28 (33±4%) and PCB-52 (14.5±0.2%); and in soils PCB-28 (56±14%) and PCB-52 (33±19%). PBDE-209 (high brominated PBDE) showed the highest relative abundance in both sample types i.e., sediment (94±7%) and soil (80±12%). These findings can be considered lower or similar when compared with other sites of the world, and are likely associated with anthropogenic activities in their surrounding area, which has experienced a fast industrial growth in the last decade. This is the first investigation of PBDEs levels in the whole study area and of PCBs in soils from the Bahía Blanca city and surrounding region. This article provides new and useful information on POP levels in the South eastern part of the GRULAC region.

Spatial and temporal analysis of the risks posed by polychlorinated biphenyl and metal contaminants in dab (Limanda limanda) collected from waters around England and Wales

The metals cadmium, mercury and lead, and the ICES7 CB levels were analysed in the common dab Limanda limanda to investigate whether concentrations of these determinants are at levels above established OSPAR assessment criteria around England and Wales. The results indicate that CB118 is above the OSPAR derived EAC at 22 out of 29 sampled stations, with 15 showing significant reductions. Cadmium is increasing significantly at six stations with two sites in the North Sea breaching corresponding OSPAR EAC. Mean results for all other PCBs and metals stayed below the EAC thresholds, with Hg concentrations even falling below BAC levels at South Eddystone located in the western English Channel. This study shows that PCBs banned over 20years ago are still found at concentrations in fish liver tissues which may pose a health risk to both the individual fish and their predators.

Molecular phylogeny and community fingerprinting of coral-associated Symbiodinium north of the Arabian Gulf

Understanding coral-Symbiodinium relationships including changes in the genotypes and the numbers of Symbiodinium can explain the ability of Kuwait coral to survive high fluctuations in water temperature. In the current study, the diversity of Symbiodinium associated with fourteen coral species from six reef systems south of Kuwait was investigated. The results proved the predominance of clade C members in all corals tested, which reflects the importance of this type in helping corals thrive in the Gulf's harsh conditions. Platygyra daedalea was the only coral found that harbored clades A, B and C in their tissue but it is the most vulnerable coral for bleaching. The total number of Symbiodinium-like cells in the seawater was 10(4) cell ml(-1) while in coral tissue and mucus 10(7) cell g(-1) and 10(7) cell ml(-1) were found, respectively, and a strong positive correlation with the seawater temperature, salinity and conductivity was found.