Pollutants In Marine Organisms Research Articles

Bioaccumulation of polycyclic aromatic hydrocarbons and their human health risks depend on the characteristics of microplastics in marine organisms of Sanggou Bay, China

Microplastics pose a threat to marine environments through their physical presence and as vectors of chemical pollutants. However, the impact of microplastics on the accumulation and human health risk of chemical pollutants in marine organisms remains largely unknown. In this study, we investigated the microplastics and polycyclic aromatic hydrocarbons (PAHs) pollution in marine organisms from Sanggou Bay and analyzed their correlations. Results showed that microplastic and PAHs concentration ranged from 1.23 ± 0.23 to 5.77 ± 1.10 items/g, from 6.98 ± 0.45 to 15.07 ± 1.25 μg/kg, respectively. The microplastic abundance, particularly of fibers, transparent and color plastic debris, correlates strongly with PAH contents, indicating that microplastics increase the bioaccumulation of PAHs and microplastics with these characteristics have a significant vector effect on PAHs. Although consuming seafood from Sanggou Bay induce no carcinogenic risk from PAHs, the presence of microplastics in organisms can significantly increases incremental lifetime cancer risk of PAHs. Thus, microplastics can serve as transport vectors for PAHs with implications for the potential health risks to human through consumption. This study provides new insight into the risks of microplastics in marine environments.

Parabens and their metabolite in a marine benthic-dominated food web from the Beibu gulf, South China Sea: Occurrence, trophic transfer and health risk assessment

Parabens are of particular concern due to their ubiquity in aquatic environments and endocrine-disrupting effects. However, information on their bioaccumulation and trophic magnification is limited. In the present study, we performed a comprehensive survey to investigate the occurrence, bioaccumulation and trophic magnification of parabens and their metabolite 4-hydroxybenzoic acid (4-HB) in a marine food web from the Beibu Gulf, South China Sea. Results showed that methylparaben (MeP) and 4-HB were the predominant target pollutants in marine organisms, with their concentrations being in the range of 0.18–13.77 and 13.48–222.24 ng/g wet weight, respectively. The bioaccumulation factors (BAFs) for target analytes were all lower than 5000, suggesting negligible bioaccumulation. However, the biota-sediment accumulation factors (BSAFs) for MeP and 4-HB were 4.51 and 3.21, respectively, which indicates significant bioaccumulation from the sediment. Furthermore, the estimated trophic magnification factor (TMF) was 2.88 for MeP, suggesting its biomagnification along the food web. In contrast, a lower TMF of 0.45 was found for 4-HB, suggesting trophic dilution along the food web. The hazard quotients (HQs) for parabens were far less than 1 in all organisms, suggesting low risks for humans through consuming marine organisms from the Beibu Gulf. This study provides substantial data on the fate and trophic transfer of parabens in a subtropical marine ecosystem.

Seawater warming intensifies nickel toxicity to a marine copepod: a multigenerational perspective

Due to human activities, marine organisms are frequently co-stressed with nickel (Ni) pollution and seawater warming; nevertheless, very scarce information is known about their interaction in marine biota under a multigenerational scenario. Here, after verifying the interaction of Ni and warming via a 48-h acute test, we conducted a multigenerational experiment (F0-F2), in which the marine copepod Tigriopus japonicus was exposed to Ni at environmentally realistic concentrations (0, 2, and 20 µg/L) under ambient (22℃) and predicted seawater warming (26℃) conditions. Ni accumulation and the important life history traits were analyzed for each generation. Results showed that Ni exposure caused Ni bioaccumulation and thus compromised the survivorship and egg production of T. japonicus. In particular, seawater warming significantly increased Ni accumulation, thus intensifying the negative effects of Ni on its survivorship and development. Overall, this study suggests that Ni multigenerational exposure even at environmentally realistic concentrations could produce a significant impact on marine copepod's health, and this impact would be intensified under the projected seawater warming, providing a mechanistic understanding of the interaction between warming and Ni pollution in marine organisms from a multigenerational perspective.

Nano-TiO2 aggravates the adverse effect of pentachlorophenol on antioxidant and immune response in anti-predatory mussels

Nano-TiO2 can act as a vector to organic compounds, such as pentachlorophenol (PCP) posing a potential threat to the marine ecosystems. Studies showed that nano pollutant toxicity can be modulated by abiotic factors, but little is known about the potential influence of biotic stressors (such as predators) on the physiological responses to pollutants in marine organisms. We explored the effects of n-TiO2 and PCP on the mussel Mytilus coruscus in the presence of its natural predator, the swimming crab Portunus trituberculatus. Exposure to n-TiO2, PCP, and predation risk showed interactive effects on antioxidant and immune parameters of the mussels. Elevated activities of catalase (CAT), glutathione peroxidase (GPX), acid phosphatase (ACP) and alkaline phosphatase (AKP), suppressed activity of superoxide dismutase (SOD), lower levels of glutathione (GSH) and increased malondialdehyde (MDA) levels indicated dysregulation of the antioxidant system and immune stress induced by single PCP or n-TiO2 exposure. Integrated biomarker (IBR) response values showed the effect of PCP was concentration dependent. Of the two used n-TiO2 sizes (25 and 100 nm), larger particles induced higher antioxidant and immune disturbances indicating higher toxicity possibly due to higher bioavailability. Compared to single PCP exposure, the combination of n-TiO2 and PCP enhanced the imbalance of SOD/CAT and GSH/GPX and led to elevated oxidative lesions and activation of immune-related enzymes. Overall, the combined impacts of pollutants and biotic stress exhibited a greater magnitude of adverse effects on antioxidant defense and immune parameters in mussels. The toxicological effects of PCP were exacerbated in the presence of n-TiO2, and the deleterious impact of these stressors was further amplified under predator-induced risk after prolonged (28 days) exposure. However, the underlying physiological regulatory mechanisms governing the interplay of these stressors and predatory cues on mussels remain elusive, warranting further investigation.

Multi-dimensional visualization of ingestion, biological effects and interactions of microplastics and a representative POP in edible jellyfish

Due to their ubiquity and potential risks, microplastics (MPs) and nanoplastics (NPs) are concerning environmental issues. Yet there are still significant knowledge gaps in understanding the tissue-specific accumulation and dynamic change of MPs and NPs in the aquatic organism and how these micro/nano-scale emerging contaminants interact with other environmental pollutants such as persistent organic pollutants (POPs). Here, in vivo imaging systems (IVIS), radioisotope tracing, and histological staining were innovatively used to reveal the fate and toxicity of fluorescently-labeled MPs/NPs and 14C-labeled 2,4,4′-trichlorobiphenyl (PCB28) in edible jellyfish Rhopilema esculentum. These contaminants' ingestion, biological effects, and interactions were visualized at cellular, tissue, and whole-body multidimensional levels. Both MPs and NPs were shown to be preferentially accumulated in the mouthlets of oral arms, and most ingested MPs/NPs were present in the extracellular environment instead of being internalized into the mesoglea. Moreover, the presence of MPs or NPs in the seawater significantly inhibited the bioaccumulation of PCB28 in the jellyfish tissue, thus alleviating physiological alteration, gastric damage, and apoptosis caused by PCB28. This study provides a multi-dimensional visualization strategy to display the distribution and biological effects of typical pollutants in marine organisms and offers new insights for understanding the impacts of MPs/NPs and POPs on marine ecosystems.

Effects of polystyrene microplastics on dechlorane plus bioaccumulation in the thick-shell mussel

The combined pollution of microplastics (MPs) and persistent organic pollutants (POPs) have attracted increasing attention from the international community in recent years. MPs can affect the toxicity, bioenrichment rate and bioavailability of POPs through adsorption and other interactions. Dechlorane Plus (DP) is a chlorinated flame retardant and a typical. DPs used mainly in various polymer materials, such as electrical wire and cable coating. The pollutions of MPs and DPs (syn and anti isomers, syn-DP [s-DP] and anti-DP [a-DP]) are ubiquitously present in the environment. However, the effect of MPs on the bioaccumulation of DP has not been reported. In this study, thick-shell mussels (Mytilus coruscus) were exposed to DPs (10 ng/L, DP10), DPs and polystyrene microplastics (PS) (10 ng/L DP +10 μg/L PS, DP10/PS10; 10 ng/LDP+20 μg/L PS, DP10/PS20) for 28 days to investigate the effect of MPs on DPs enrichment. Thick-shell mussels accumulated DPs in the adductor muscle, gill, and gonad showed an increasing trend with time, but the concentration of DPs in the visceral mass does not show a time-dependent manner. The concentration of DPs in the gonads and gills was significantly affected by the concentration of PS (p < 0.05), but there was no significant correlation between the concentration of DPs and the concentration of PS in the adductor muscle and visceral mass (p > 0.05). Moreover, DPs showed selective enrichment of syn-DP in thick-shell mussel tissues, and there was no significant correlation between this result and PS concentration (p > 0.05). These findings provide a new entry point for studying the interaction between microplastics and persistent organic pollutants in marine organisms.

Characteristics, Source Analysis, and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) Pollution in Marine Organisms from Estuaries of Changhua River in Hainan Province

To assess the contamination by polycyclic aromatic hydrocarbons (PAHs) in organisms in the estuary of Changhua River in Hainan, we determined the content of 16 priority PAHs by gas chromatography and mass spectrometry (GC-MS). The composition, source, and potential edible risk of PAHs were studied. The results showed that the total PAHs of demersal fish (wet weight, same below), crustaceans, and pelagic fish were 5.52-787.98, 12.18-154.64, and 10.20-199.79 ng·g-1, respectively, and the average contents were 83.21, 64.72, and 89.48 ng·g-1, respectively. There were some differences in the content of PAHs in various organisms. The average content followed the order of pelagic fish > demersal fish > crustaceans. Compared with other areas in the country and abroad, the content of marine organisms'PAHs in the estuary of the Changhua River was above the medium level. The result of isomer characteristic ratio showed that the PAHs of 33 organisms mainly came from the combustion sources (petroleum combustion and biomass combustion) and petroleum sources. Moreover, demersal fish were greatly affected by combustion sources, while pelagic fish were greatly affected by petroleum sources. Human risk assessment indicated that the content of benzopyrene (BaP) was within the limits set by the European Union. Most of the organisms in the estuary of Changhua River were within the safe range of consumption, but the long-term consumption of these seafoods may pose a potential health risk (1.0×10-5≤ILCR<1.0×10-4).

Effects of microplastics and mercury on manila clam Ruditapes philippinarum: Feeding rate, immunomodulation, histopathology and oxidative stress

Plastic pollution, which is one of the most important environmental problems at the present time, has been understood recently, and the effects of this pollution on ecosystem and biota are becoming a growing problem, especially in the aquatic ecosystems. Direct or indirect exposure to those particles leads to adverse effects on marine organisms. In the marine environment, plastic materials interact with other pollutants such as metals, thereby affecting the uptake levels of those pollutants in marine organisms. In the present study, the Manila clam Ruditapes philippinarum was exposed to polyethylene microbeads and mercury chloride in single, combined and incubated form at environmentally relative concentrations for one week in controlled laboratory conditions. The uptake and tissue distribution of both stressors as well as the vector role of microplastics on mercury uptake in the organisms were investigated. Filtration rates, biomarkers for immunomodulation and oxidative stress, and histological alterations were also evaluated. Microplastics were ingested by the clams, and translocated to the various tissues. However, contaminated microplastics displayed a negligible vector role in terms of mercury bioaccumulation in the clams. The single and interactive exposure of the stressors reduced the filtration rate in the clams. Both pollutants affected the immune system of the organisms. Histological alterations were determined in the gill and digestive gland tissues of the clams among the treatment groups, although oxidative stress biomarkers remained unchanged. This study suggests that the vector role of polyethylene microplastics in mercury uptake is negligible and reveals that the single and interactive one-week exposure of two pollutants induce toxicity in the manila clams.

InVivo Accumulation of Plastic-Derived Chemicals into Seabird Tissues.

Plastic debris is ubiquitous and increasing in the marine environment [1]. A wide range of marine organisms ingest plastic, and its impacts are of growing concern [2]. Seabirds are particularly susceptible to plastic pollution because of high rates of ingestion [3]. Because marine plastics contain an array of hazardous compounds, the chemical impacts of ingestion are concerning. Several studies on wild seabirds suggested accumulation of plastic-derived chemicals in seabird tissues [4-7]. However, to date, the evidence has all been indirect [4-7], and it is unclear whether plastic debris is the source of these pollutants. To obtain direct evidence for the transfer and accumulation of plastic additives in the tissues of seabirds, we conducted an invivo plastic feeding experiment. Environmentally relevant exposure of plastics compounded with one flame retardant and four ultraviolet stabilizers to streaked shearwater (Calonectris leucomelas) chicks in semi-field conditions resulted in the accumulation of the additives in liver and adipose fat of 91 to 120,000 times the rate from the natural diet. Additional monitoring of six seabird species detected these chemical additives only in those species with high plastic ingestion rates, suggesting that plastic debris can be a major pathway of chemical pollutants into seabirds. These findings provide direct evidence of seabird exposure to plastic additives and emphasize the role of marine debris ingestion as a source of chemical pollution in marine organisms.

Aryl hydrocarbon receptor-mediated potencies in field-deployed plastics vary by type of polymer

Plastic is able to sorb environmental pollutants from ambient water and might act as a vector for these pollutants to marine organisms. The potential toxicological effects of plastic-sorbed pollutants in marine organisms have not been thoroughly assessed. In this study, organic extracts from four types of plastic deployed for 9 or 12 months in San Diego Bay, California, were examined for their potential to activate the aryl hydrocarbon receptor (AhR) pathway by use of the H4IIE-luc assay. Polycyclic aromatic hydrocarbons (PAH), including the 16 priority PAHs, were quantified. The AhR-mediated potency in the deployed plastic samples, calculated as bio-TEQ values, ranged from 2.7 pg/g in polyethylene terephthalate (PET) to 277 pg/g in low-density polyethylene (LDPE). Concentrations of the sum of 24 PAHs in the deployed samples ranged from 4.6 to 1068 ng/g. By use of relative potency factors (REP), a potency balance between the biological effect (bio-TEQs) and the targeted PAHs (chem-TEQs) was calculated to 24–170%. The study reports, for the first time, in vitro AhR-mediated potencies for different deployed plastics, of which LDPE elicited the greatest concentration of bio-TEQs followed by polypropylene (PP), PET, and polyvinylchloride (PVC).

Projected amplification of food web bioaccumulation of MeHg and PCBs under climate change in the Northeastern Pacific

Climate change increases exposure and bioaccumulation of pollutants in marine organisms, posing substantial ecophysiological and ecotoxicological risks. Here, we applied a trophodynamic ecosystem model to examine the bioaccumulation of organic mercury (MeHg) and polychlorinated biphenyls (PCBs) in a Northeastern Pacific marine food web under climate change. We found largely heterogeneous sensitivity in climate-pollution impacts between chemicals and trophic groups. Concentration of MeHg and PCBs in top predators, including resident killer whales, is projected to be amplified by 8 and 3%, respectively, by 2100 under a high carbon emission scenario (Representative Concentration Pathway 8.5) relative to a no-climate change control scenario. However, the level of amplification increases with higher carbon emission scenario for MeHg, but decreases for PCBs. Such idiosyncratic responses are shaped by the differences in bioaccumulation pathways between MeHg and PCBs, and the modifications of food web dynamics between different levels of climate change. Climate-induced pollutant amplification in mid-trophic level predators (Chinook salmon) are projected to be higher (~10%) than killer whales. Overall, the predicted trophic magnification factor is ten-fold higher in MeHg than in PCBs under high CO2 emissions. This contribution highlights the importance of understanding the interactions with anthropogenic organic pollutants in assessing climate risks on marine ecosystems.

Interspecific variation of essential and non-essential trace elements in sympatric seabirds

Chemical pollution is a growing issue for ocean ecosystems, threatening especially apex predators because they bioaccumulate persistent chemical pollutants such as non-essential trace elements. The trophic position is thus a key aspect when assessing the impacts of environmental pollution in marine organisms. Here we investigate the differences in the concentrations of essential (Cu, Cr, Se, and Zn) and non-essential elements (Hg, Al, As, Cd, and Sr), in muscular and hepatic tissues of four sympatric non-migratory seabirds (namely Sula leucogaster, Larus dominicanus, Fregata magnificens, and Thalasseus acuflavidus), which were found stranded along the Brazilian coast. The observed hepatic and muscular interspecific differences in elemental concentrations indicated that these sympatric seabirds are differently exposed to persistent contaminants circulating in the food web due to differences with respect to known feeding behaviours and prey preferences. Moreover, we found a consistent co-accumulative relationship between Se and Hg molar levels in liver tissues with mean Se:Hg molar ratio above 1. This relationship supports previous studies indicating that Se, via the formation of SeHg complexes, plays an essential biochemical role in the detoxification process of methyl mercury in seabirds. Our results suggest that feeding behaviour is an important factor associated to the interspecific differences of trace element concentrations in seabirds. However, traits other than feeding preferences (e.g. age) may also play an important role in the accumulation of these elements.

Heavy Metals and Persistent Organic Pollutants in Marine Organisms from Two Sicilian Protected Areas: Strait of Messina and Cape Peloro Lakes

This paper reviews several scientific articles regarding levels of organic and inorganic contaminants in a variety of marine species coming from two Sicilian protected areas: the Strait of Messina and Cape Peloro lakes (Ganzirri and Faro). Moreover, different analytical techniques for the determinations of organic and inorganic contaminants, and the procedures adopted for the analyses, are summarized. Quantitative and qualitative determination of organic pollutants was performed by High Resolution Gas Chromatography-Electron Capture Detection and confirmed by Gas Chromatography-Mass Spectrometry. The concentrations of inorganic elements were determined by Atomic Absorption Spectrophotometry, derivative Stripping Chronopotentiometry, Inductively Coupled Plasma-Optical Emission Spectrometry and Inductively Coupled Plasma -Mass Spectrometry. Results provide evidence that organic and inorganic residues found in some of the examined samples were mostly below the Maximum Residue Levels (MRLs). In conclusion, species analyzed in these studies were safe for human consumption and, consequently the investigated environments were estimated as free from toxicological risk. Keywords: Organic and inorganic pollutants, marine species, environmental biomarkers, strait of messina, cape peloro lakes.

Legacy and emerging halogenated organic pollutants in marine organisms from the Pearl River Estuary, South China

A suite of legacy and emerging halogenated organic pollutants (HOPs) were measured in marine organisms (coastal fish and invertebrates) from the Pearl River Estuary, South China, to investigate the current contamination status after the Stockholm Convention was implemented in China. Dichlorodiphenyltrichloroethane and its metabolites (DDTs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were detected in all samples at concentrations of 54–1500, 16–700, and 0.56–59ng/g lipid weight, respectively. Dechlorane Plus (DP), decabromodiphenyl ethane (DBDPE), 2,3,5,6-tetrabromo-p-xylene (pTBX), and pentabromotoluene (PBT) were also found at concentrations of ND (non-detectable) to 37ng/g lipid weight. The concentrations of these investigated contaminants in the present study were at moderate levels, as compared with those reported in other regions. Significant interspecies differences were found in the levels of DDTs, PCBs, PBDEs and the alternative halogenated flame retardants (AHFRs). DDTs were the predominant HOPs in those species and represented >50% of the total HOPs, followed by PCBs, PBDEs, and AHFRs. The total estimated daily intakes (EDIs) of DDTs, PCBs, PBDEs, and AHFRs were 28, 12, 1.0, and 0.18 (ng/kg)/d, respectively, via seafood consumption. These concentrations are not expected to pose health risks to humans.

Oxidative metabolism of chemical pollutants in marine organisms: molecular and biochemical biomarkers in environmental toxicology.

Oxidative stress biomarkers are widely used in marine ecotoxicology. Environmental pollutants enhance intracellular formation of oxyradicals through several mechanisms, but complex oxidative interactions occur in response to chemical mixtures. Metabolism of individual classes of pollutants can be influenced by a sophisticated network of prooxidant relationships, reciprocal and cascade effects, changes of redox-sensitive signaling proteins, and transcription factors. Chemically mediated pathways can affect antioxidant responses at different levels, including pretranscriptional, transcriptional, protein, and catalytic functions; such mechanisms remain largely unexplored in marine organisms. Molecular responses of antioxidants are frequently not paralleled by expected biochemical changes or cellular effects, and caution is needed when interpreting the effects of environmental pollutants. Results on antioxidant variations can be influenced by mRNA stability and protein turnover, different timing for transcriptional and translational mechanisms, metabolic capability of tissues, posttranscriptional modifications of proteins, biphasic responses of antioxidant enzymes, and adaptation mechanisms to chronic pollution.

Biochemical Response of the Cyclopoida Copepod Apocyclops Borneoensis Exposed to Nickel

The use of biomarkers to evaluate the biological effects of pollutants in marine organisms represents a recent tool in biomontoring programs. The cyclopoida copepod Apocyclops borneoensis was exposed to different Ni treatments [0 (control), 10, 100, 1000 μg l -1 Ni] for 1, 2, 4, 7, 14 days. At each exposure time, acetylchlinesterase (AChE), superoxide dismutase (SOD), glutathione-S-transferase (GST), glutathione (GSH) were analyzed. Additionally, lipid peroxidation (LPO) level was measured after a 14-day exposure. The results show that Ni treatment significantly stimulated copepod’s antioxidants SOD, GST and GSH at environmentally relevant concentrations after a certain exposure time. On the other hand, the exposure time significantly affected SOD and GSH. In contrast, Ni exposure significantly decreased LPO level, implying that the factor involved in LPO might not significantly depend on the operations and functions in the antioxidant defense system. In addition, Ni might also be a neurotoxic agent to copepods via changing AChE activity.

Effects of heavy metals on the expression of a zinc-inducible metallothionein-III gene and antioxidant enzyme activities in Crassostrea gigas

Sequestration by metallothioneins and antioxidant defense are two kinds of important defense mechanisms employed by mollusks to minimize adverse effects caused by heavy metal contaminants in marine environment. In the present study, a novel metallothionein gene, CgMT-III, was cloned from Crassostrea gigas, consisting of eighteen conserved cysteine residues and encoding a MT III-like protein with two tandem β domains. The expression level of CgMT-III transcript induced by zinc was much higher than that induced by cadmium exposure. It suggested that CgMT-III was perhaps mainly involved in homeostatic control of zinc metabolism, which was distinct from previously identified MTs in C. gigas. Among the tested antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), SOD and GPx showed varying up-regulations in a tissue-specific manner, while CAT activities were inhibited in both gill and hepatopancreas from C. gigas exposed to heavy metals. It can be inferred that CgMT-III was mainly involved in zinc homeostasis, and CgMT-III gene together with CAT enzyme could be potential biomarkers to indicate heavy metal, especially zinc pollution in marine organisms.

Seasonal and inter-annual variability of DNA integrity in mussels Mytilus galloprovincialis: A possible role for natural fluctuations of trace metal concentrations and oxidative biomarkers

The DNA strand fragmentation as analyzed by the Comet assay is a common biomarker widely used to assess the genotoxic potential of chemical pollutants in marine organisms. However, basal levels of DNA strand breaks can be influenced also by factors unrelated to chemical exposure, and a better knowledge on the natural variability of such response would thus be important to discriminate the effects of anthropogenic activities. In this respect, the aim of the present work was to characterize the fluctuations of DNA strand breaks in mussels, Mytilus galloprovincialis, seasonally sampled over a 3 year period from a reference site along the Adriatic coast. Parameters reflecting DNA integrity exhibited significant seasonal changes in mussels haemocytes, with considerable differences between various sampling years. Comparing such results with those previously obtained on the natural fluctuations of trace metal concentrations and oxidative stress biomarkers in mussels tissues, significant correlations were obtained between DNA strand breaks with levels of Ba, Cd, Cu, Hg, Ni, Se, activity of catalase and content of malondialdehyde. Although mechanisms remain to be demonstrated, the overall results of this work suggest the potential role of natural prooxidant factors in affecting the baseline levels of DNA integrity in mussels, and confirm that natural variability of such responses should be carefully considered when monitoring the impact of genotoxins in marine ecosystems.

Integrated use of biomarkers (superoxide dismutase, catalase and lipid peroxidation) in mussels Mytilus galloprovincialis for assessing heavy metals’ pollution in coastal areas from the Saronikos Gulf of Greece

Mussels are used as sentinel organisms and bioindicators to evaluate the toxic effects of chemical pollutants in marine organisms, especially heavy metals, representing an important tool for biomonitoring environmental pollution in coastal areas. Antioxidant defence enzymes play an important role in cellular antioxidant defence systems and protect from oxidative damage by reactive oxygen species (ROS). Indigenous mussels Mytilus galloprovincialis of the Saronikos Gulf of Greece were used for monitoring heavy metal pollution in three polluted sites in the area and in one unpolluted site. Seasonal variations of the activity of antioxidant defence enzymes, superoxide dismutase (SOD) and catalase (CAT), as well as lipid peroxidation (LP) were measured as biomarkers in a period of three years in relation to concentrations of trace metals in their gills and mantle and compared to mussels from an unpolluted sampling site. SOD activity increased at least 2 fold at the polluted sites when compared to the control site (the high activity was recorded in the spring time). CAT activity was increased 2–3 times at the polluted sites, with high activity in the winter and spring time, compared to the control site. LP concentration was twice higher at the polluted sites, following the same seasonal pattern. Trace metals contents in mussels collected at polluted sites were 3–4 fold higher compared to the control site and showed moderate variations along the months, with a winter maximum followed by a summer pre-spawning minimum matching the seasonal trends of temperature and salinity. Our results showed that metal pollution in the Elefsis Bay (the most polluted coastal area) causes relatively medium levels of oxidative stress in tissues of mussels due to cellular oxy-radical generation. This study, which is the first in the area, showed that seasonal variations of the activity of antioxidant defence enzymes and LP concentrations in mussels can be used as potential biomarkers of toxicity for long-term monitoring in marine coastal ecosystems.

Indices for the assessment of environmental pollution of the Baltic Sea coasts: Integrated assessment of a multi-biomarker approach

Two mathematical methods to assess the “health status” of flounder ( Platichthys flesus), eelpout ( Zoarces viviparus) and blue mussel ( Mytilus spp.) populations of the Baltic Sea were applied on selected biomarker data collected during the EU project “BEEP” (Biological Effects of Environmental Pollution on Marine Coastal Ecosystems). The Bioeffect Assessment Index (BAI) and the Integrated Biomarker Index (IBR) combine different biomarkers to single values, which can be used to describe the toxically-induced stress level of populations in different areas. Both indices determined here produced essentially similar results, which in most cases agreed with the known contamination levels in the different study areas. Advantages and limitations of index applications and interpretations are critically discussed. The use of indices provides comprehensive information about biological effects of pollution in marine organisms and may therefore serve as a useful tool for environmental management by ranking the pollution status of marine coastal areas.