Metal and metallothionein concentrations in Paracentrotus lividus from Amvrakikos gulf (Ionian Sea-Greece)

Concentrations of Cd, Cu, Cr, Ni, Zn, Fe and metallothioneins (MTs) were measured in the gonads of Paracentrotus lividus from Amvrakikos gulf (Ionian Sea, Greece). Three natural populations were selected; two of them, growing inside the gulf (Agios Thomas and Koronisia), presented higher density and smaller body size than the population living in a coastal area just outside the gulf (Mytikas). Metal and MT levels were not elevated, with the exception of Zn, showing high values related to the reproduction stage of the sea urchins. Significant geographical variations were recorded in the concentrations of Cu, Zn, Cd, Cr and MTs. The highest mean and maximum values of Cu, Zn and MTs were recorded in Agios Thomas while Cd and Cr were higher in Mytikas population. Copper, Zn, Fe and MT concentrations were negatively correlated to the sea urchin body size, while a positive concentration-size relationship was observed for Cd. Although all studied populations grow in a low metal level marine environment, urchins with smaller body size living in a food limited marine environment showed higher gonadosomatic index, metal concentrations and MT levels in their gonads (Agios Thomas and Koronisia) than larger specimens growing in a food unlimited area (Mytikas).     

Retrospective monitoring of persistent organic pollutants,including PCBs,PBDEs, and polycyclic musks in blue mussels (Mytilus edulis) and sediments from New Bedford Harbor,Massachusetts, USA: 1991–2005

Blue mussels (Mytilus edulis) and sediments collected from 1991 to 2005 from New Bedford Harbor (NBH), MA, were analyzed for two polycyclic musks (HHCB or Galaxolide® and AHTN or Tonalide®), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs). HHCB and AHTN were found in mussel tissues at mean concentrations of 836 and 376 ng/g lipid weight (lw), respectively, which were two- to seven-fold higher than those found at a reference site. Mean concentrations of HHCB and AHTN in NBH sediments were 12 and 6.3 ng/g dry weight (dw), respectively. Four- and five-ringed PAHs, such as phenanthrene, anthracene, fluoranthene, and pyrene, collectively accounted for 61 % of the ∑PAHs concentrations in mussels from NBH. Mean ΣPCB concentrations in mussels from upper and lower NBH were 942 and 182 μg/g lw, respectively, and were dominated by tetra- and penta-chlorobiphenyl congeners, collectively accounting for 61 % of the ΣPCB concentrations. The mean concentration of ∑PBDEs in mussels from NBH was 277 ng/g lw, and no significant difference existed in the concentrations between upper and lower NBH. DDTs were the major OCP found in mussels, found at a mean concentration of 778 ng/g lw. The concentrations of HHCB, AHTN, ΣPBDEs, ΣPAHs, and DDTs in mussels decreased significantly (r ²?≥?0.56, p?≤?0.052) from 1991 to 2005. The concentrations of PCBs and chlordanes did not exhibit a decreasing trend in mussel tissues (r ²?<?0.50; p?>?0.076) from 1991 to 2005. Based on the temporal trends in the concentrations of HHCB, AHTN, ∑PAHs, and ∑PBDEs found in mussels from NBH, it was estimated that between 5.5 and 12 years were required for the concentrations of these compounds to decrease by half (i.e., environmental halving time) of the levels found in 1991.     

Trends of total cadmium, copper, and zinc in the zebra mussel (Dreissena polymorpha) along the upper reach of the St. Lawrence River: 1994—2005

This study examines spatial and temporal variability of bioaccumulation of cadmium, copper, and zinc in tissues of zebra mussels in the upper reach of the St. Lawrence River which originates at the outflow of Lake Ontario. It was hypothesized that concentrations of these metals in mussel tissues would decline over time and decrease with increasing distance from the outlet of Lake Ontario as a result of on-going efforts to reduce contaminant discharges into the lake. Size of mussels was also evaluated as a factor influencing bioaccumulation. Mussels were collected annually in October from six sites from 1994 to 2005, including one site near a local industry. Individuals were grouped into five or more size classes per site in each year. Soft tissues were analyzed for total cadmium, copper and zinc. Concentrations of cadmium and copper in tissues varied significantly both spatially and temporally. Cadmium concentrations were elevated at most sites; copper concentrations were moderately elevated compared with other studies in the Lake Ontario basin and St. Lawrence River. Zinc showed the most uniformity in mussels possibly due to internal regulation and to low levels of environmental exposure. Animal size correlated with copper concentrations of tissues in approximately 30% of samples but infrequently for cadmium and zinc. Cadmium and copper levels were found to decline downstream over time. Inter-annual variability of metal concentrations in mussel tissues suggests utilization in long-term monitoring programs to discern significant trends.     

The Influence of the Biometric Parameters on Metallothionein and Metal Level in the Heat-Treated Cytosol of the Whole Soft Tissue of Transplanted Mussels

The influence of the biometric parameters (shell mass, whole soft tissue mass, condition index) on MT and metal levels in the heat-treated cytosol of the whole soft tissue of transplanted mussels was studied over the period of one year. The positive correlation of three metals (Cd, Fe, Zn) with the shell mass indicated to time-dependent increase of their contents. Strong correlation of Mn content with the whole soft tissue mass (r = 0.74, p < 0.0001), and almost identical changes of these two parameters over the year make Mn a good indicator of mussel's condition. As opposed to the other metals, Cu content does not exhibit connection with biometry. On the other hand, MTs are highly influenced by biometry. As much as 65% of their variability could be explained by the changes of the shell mass and the whole soft tissue mass. Consequently, it is difficult to distinguish if the obtained positive correlation between Cd and MTs (r = 0.48, p < 0.05) reflects MT induction by Cd, or Cd accumulation as a result of age-dependent increase of MTs. Due to the strong influence of the biometry on MT level, the whole soft tissue is not considered as the best choice for measuring MTs as a biomarker. Better option would be to isolate a specific tissue that shows indisputable connection between MT induction and metal accumulation.     

Monitoring water quality in Sydney Harbour using blue mussels during remediation of the Sydney Tar Ponds,Nova Scotia,Canada

Using mussels as monitoring tools we measured water quality in Sydney Harbour during a large scale, multi-year remediation project of the Sydney Tar Ponds (STPs); one of Canada's most contaminated sites. Chemical contaminants were measured in blue mussels (Mytilus edulis) in Sydney Harbour, which were used as monitoring tools to assess the spatio-temporal distribution of polycyclic aromatic hydrocarbons (PAHs); polychlorinated biphenyls (PCBs); metals (As, Cd, Cu, Hg, Pb, Zn) and lipid content during baseline and 3 years of remediation. The overall spatio-temporal distribution of chemicals in mussels was also compared to contaminants in other marine indicators (e.g., sediment, water and crab tissue). Measured metal concentrations in mussels showed some minor temporal variability (4 years), but these did not appear to be directly related to remediation activities, with the highest concentrations of As, Hg and Zn measured at reference stations. Most measured contaminants showed stable or potentially decreasing concentrations during the study, except Pb and Zn. Individual PAH compounds were mostly undetected during baseline and remediation, except for fluoranthene and pyrene. Concentrations of fluoranthene in mussels and deep water samples were moderately related. Generally, PCBs were undetected (<0.05 μg g^?1), except during year 2 remediation at some near-field stations. Contaminants measured during this study were at much lower concentrations than previously reported in other studies of mussels in Sydney Harbour and eastern Canada. This is likely due to the ongoing natural recovery of Sydney Harbour and to a lesser extent because of the environmental mitigation protection measures implemented during remediation activities at the STPs. The lack of detection of most individual PAHs and PCBs, plus relatively low bio-accumulation of metals observed during baseline and remediation attest to the effectiveness of using mussels as monitoring tools for environmental quality.     

Dispersion and bioaccumulation of elements from an open-pit olivine mine in Southwest Greenland assessed using lichens, seaweeds, mussels and fish

This study investigated dispersion and bioaccumulation of mining-related elements from an open-pit olivine mine at Seqi in Southwest Greenland (64°?N) using lichens (Flavocetraria nivalis), seaweeds (Fucus vesiculosus), mussels (Mytilus edulis) and fish (Myoxocephalus scorpius). The mine operated between 2005 and 2009, and samples were taken every year within a monitoring area 0–17 km from the mine during the period 2004–2011. A total of 46 elements were analysed in the samples. After mining began, highly elevated metal concentrations, especially nickel (Ni), chromium (Cr), iron (Fe) and cobalt (Co), were observed in lichens relative to pre-mining levels (up to a factor of 130) caused by dust dispersion from the mining activity. Elevated metal concentrations could be measured in lichens in distances up to ~5 km from the mine/ore treatment facility. Moderately elevated concentrations of Ni and Cr (up to a factor of 7) were also observed in seaweeds and mussels but only in close vicinity (<1 km) to the mine. Analyses of fish showed no significant changes in element composition. After mine closure, the elevated metal concentrations in lichens, seaweeds and mussels decreased markedly, and in 2011, significantly elevated metal concentrations could only be measured in lichens and only within a distance of 1 km from the mine.     

Bioaccumulation of PAHs in the Zebra Mussel at Times Beach, Buffalo, New York

The zebra mussel, Dreissena polymorpha, was utilized in an in situ study in the Times Beach Confined Disposal Facility (CDF) located in Buffalo, New York, Mussels, placed both in the water column (upper position) and at the sediment surface (lower position), survived a 34-day exposure to the CDF. At the CDF, total polycyclic aromatic hydrocarbon (PAH) concentrations in the water column were below detection limits (<0.010 mg 1-1), mean total PAH concentrations in the sediment were 164.41 mg kg-1, and mean total PAH concentrations in mussel tissues after the 34-day exposure were 6.58 mg kg-1. PAH concentrations in mussels exposed for 34 days at the CDP were compared to a baseline PAH concentrations in mussel tissue prior to study initiation (Day 0), and mussel tissue from the reference site (Black Rock Channel Lock). There was a significant increase in total PAHs in mussel tissues over the 34 Day period at the CDF. No significant accumulation occurred at the reference site. PAHs which increased significantly in mussel tissue at the CDF were fluoranthene, pyrene, chrysene, and benzo(a)anthracene. Benzo(a)anthracene concentrations increased significantly in mussels at the upper position overall at Times Beach. Concentrations of Total PAHs, fluoranthene, pyrene, and chrysene were not related to position.     

Heavy Metal Levels in Biota and Sediments in the Northern Coast of the Marmara Sea

Concentration of Cd, Co, Cr, Ni, Zn, Fe, Mn, Pb and Cu were determinedin biota and sediment samples collected from the Marmara Sea in Turkey. The levels of Zn, Fe, Mn, Pb and Cu in the macroalgae are higher than previous studies in the Marmara Sea. Moreover, Cu and Zn concentrations at the present study are significantly high than Bosphorus and Black Sea algae. The order heavy metal concentrations in the mussel samples was: Fe > Zn > Ni > Mn > Cu > Pb > Cr > Cd > Co. The metal concentrations are generally lower when compared with the Black Sea mussels except Pb. At the same time, concentrations of Pb, Cu and Zn in the mussel species are lower when compared with the results in the Aegean Sea. The ranges of Mn and Cu in the tested fish samples are higher than Black Sea fish. On the other hand, Cd, Co, Cr, Zn and Pb concentrations are lower. The northern coast of the Marmara Sea having the highest metal concentrations in sediments as follows: Co, Cr, Ni, Fe at ?arköy ; Pb, Cu at M. Ere?li; Cd, Zn, Mn at Menek?e. The heavy metal levels in the sediment samples are lower than other areas in the Marmara Sea.     

Culturable heterotrophic bacteria in seawater and Mytilus galloprovincialis from a Mediterranean area (Northern Ionian Sea – Italy)

Although Mar Piccolo of Taranto (Ionian Sea, Italy) is one of the most important Mytilus galloprovincialis farming areas, data concerning the natural bacterial microbiota of these mussels and their surrounding environment are still scant. This study was carried out seasonally, throughout a year, to determine culturable heterotrophic bacteria both in the water and mussels samples collected at three sampling sites in the Northern Ionian Sea: S. Vito, Lido Gandoli and Lido Silvana. Culturable heterotrophic bacteria abundance was determined by spread plate on Marine Agar. Heterotrophic bacteria were identified by several morphological, culture and biochemical methods. Bacterial concentrations were higher in the mussel samples compared to the corresponding seawater throughout the year. Among Gram negative heterotrophic bacteria, Aeromonas prevailed both in the water (18%) and mussel samples (40%). Other genera such as Moraxella, Pseudomonas, Alcaligenes, Acinetobacter, Flavobacterium, Chromobacterium, Photobacterium and Flexibacter were present with different percentages of isolation. Bacilli were predominant among Gram positive bacteria. Some genera (Lucibacterium and Vibrio) were present only in mussel samples. The results obtained contribute to improve the knowledge on both the bacterial abundance and diversity in mussels and the surrounding seawater in the Northern Ionian Sea.     

Organotin Compounds and Selected Metals in the Marine Environment of Northern Adriatic Sea

The extent of pollution with organotin compounds and Cd, Pb, Ni, Cu, Zn, Cr, Mn, V, Co and Al was investigated in sediments and mussels (Mytilus galloprovincialis) from the Slovenian costal area of the Northern Adriatic Sea. Sampling was performed in Marina Portorož, Dockyard Izola, non exposed area of the Bay of Mesečev zaliv and in Mariculture Sečovlje. Mussels were taken in the summer and winter time, while sediments were collected during the winter sampling. Organotin compounds were determined by gas chromatography—mass spectrometry and metals by flame or electrothermal atomic absorption spectrometry. The accuracies of the analytical procedures were checked by the analysis of standard reference materials CRM 477 mussel tissue and PACS 2 marine sediment (organotin compounds) and SRM 2976 mussel tissue and CRM 320 river sediment (metals). Good agreements between certified and determined values were obtained. Normalization procedure to Al was applied to estimate the anthropogenic inputs of metals in sediments. The analyses of sediments demonstrated moderate pollution with organotin compounds in Marina Portorož and in Dockyard Izola. Concentrations of tributyltin species were higher than those of dibutyltin and monobutyltin. In mussels substantial contamination with tributyltin was observed in Marina Porotrož and Dockyard Izola. The extent of pollution was higher in the winter time. The analysis of metals in sediments exhibited elevated concentrations in Marina Portorož and Dockyard Izola. Data from the normalization procedure indicated the anthropogenic inputs of Cu, Zn and Cr in Marina Portorož and Mn in Bay of Mesečev zaliv and Dockyard Izola. Mussels, as accumulators of pollutants, in general contained higher metal concentrations during winter time in Dockyard Izola.     

A large scale survey of trace metal levels in coastal waters of the Western Mediterranean basin using caged mussels (Mytilus galloprovincialis)

A large scale study of trace metal contamination (Hg, Cd, Pb and Ni) by means of caged mussels Mytilus galloprovincialis was undertaken along the coastal waters of the Western Mediterranean Sea within the context of the MYTILOS project. Individual mussels from an homogeneous population (shell size 50 ± 5 mm) obtained from an aquaculture farm were consecutively caged and deployed at 123 sites located in the Alborán, North-Western, South-Western and Tyrrhenian sub-basins for 12 weeks (April-July) in 2004, 2005 and 2006. After cage recoveries, both the metal content in the whole mussel tissue and the allometric parameters were measured. Statistical analysis of the datasets showed significant differences in concentrations between sub-basins for some metals and mussel condition index (CI). Linear regression models coupled to the CI were revisited for the data adjustment of certain trace metals (Hg, Cd and Ni), and four level categories were statistically derived to facilitate interregional comparison. Seawater masses surrounding coastal areas impacted by run-off from land mineralised coasts and industrial activities displayed the highest concentration ranges (Hg: 0.15-0.31 mg kg(-1) dw; Cd: 1.97-2.11; Ni: 2.18-3.20 and Pb: 3.1-3.8), although the levels obtained in most of the sites fitted within moderate or low categories, and they could be considered as baseline concentrations. However, few sites considered little-influenced by human activities, at present, showed high concentrations of Cd, Ni and Pb, which constitute new areas of concern. Overall, the use of active biomonitoring (ABM) approach allowed to investigate trace metal contamination in order to support policy makers in establishing regional strategies (particularly, with regard to the European Marine Strategy Directive).     

Statistical analysis of heavy metals in Cerastoderma edule glaucum and Venerupis aurea laeta from Ganzirri Lake, Messina (Italy)

Our study was carried out on two species of clams, Venerupis aurea laeta and Cerastoderma edule glaucum, from Ganzirri Lake considered as “environmental biomarkers” for their changes in physiology, morphology or distribution under the influence of substances in the environment. The aim of the present study was to conduct a statistical analysis on Venerupis and Cerastoderma to investigate the difference between the two autochthonous clams according to the presence of metals, and to link metal concentrations to the reproductive cycle of clam during 2009–2010. Metal analysis was carried out with inductively coupled plasma mass spectrometry (ICP-MS). Accuracy and precision were assessed by analyzing the certified standard matrix: mussel tissue NIST SRM 2976. The multivariate analysis was made using the SPSS 13.0 software package for Windows (SPSS Inc., Chicago, IL). In this study, the concentrations of some metals found in clam tissues showed seasonal cycles with higher values in summer than in winter. The significances of metal concentrations differences between Venerupis and Cerastoderma samples were estimated with Mann–Whitney U-test. The concentrations of Ag, As, Cd, Mn, Se and Zn show a significant p-level that suggests a difference between the two group samples. Statistical analysis showed that the link of metal concentrations to the reproductive cycles of Venerupis and Cerastoderma was not evident.     

Mussel isotope signature as indicator of nutrient pollution in a freshwater eutrophic lake: species, spatial, and seasonal variability

Stable nitrogen isotope ratios of five mussel species from littoral and pelagic areas were investigated with different trophic states in the eutrophic Lake Taihu, the third largest lake in China. Interpopulation variability for these mussels was relatively small in foot tissues because of the slow turnover time. Seasonal and spatial variations among the δ ¹⁵N values of mussels might be due in part to the natural variation in δ ¹⁵N values of potential food sources and the variation in the amount of human pollutions discharged into various locations of the lake. Although the increase of mussel δ ¹⁵N values was accompanied by the increase of nutrient concentrations in most situations in this study, statistically significant correlations were only 22% of the total correlations in this survey, which might be attributed to the different time-scale variations in nutrient concentrations and isotope signatures and the unknown details of the trophic pathways and metabolism for incorporation of these nutrients.     

Use of metallothioneins as biomarkers for environmental quality assessment in the Gulf of Gabès (Tunisia)

Detection and assessment of the impact of pollution on biological resources imply increasing research on early-warning markers such as metallothioneins (MTs) in metal exposure. In this paper, we have collated published information on the use of metallothioneins and metallothionein-like proteins (MTLPs) as biomarkers for environmental quality assessment in the Gulf of Gabès. In this area, some species of fish and bivalve were used as bioindicators of pollution. In these species, an induction of MTs/MTLPs by the essential metals such as Cu and Zn and the non-essential metals such as Cd was observed by different authors who suggest the potential use of these proteins as biomarkers. However, MT concentrations can be influenced by many biotic (sex, maturity stages, and tissues) and abiotic factors (temperature, salinity, and pH). This is essentially the case in field studies where many parameters can randomly affect MT levels, so the endogeneous regulation of MTs must be considered before using MTs as an indicator of heavy metal exposure. Moreover, the use of biomarker cannot be examined independently of the evaluation of techniques that enable its quantification. Therefore, the approach to the use of MTs/MTLP as biomarkers of exposure for an assessment of the physiological status of aquatic organisms is discussed in this paper.     

Geochemistry of the suspended sediment in the estuaries of the Mandovi and Zuari rivers, central west coast of India

The geochemistry of the suspended particulate matter (SPM) collected during the monsoon was determined to identify the sources of SPM and to understand the physicochemical processes in the Mandovi and Zuari river estuaries. The concentrations of SPM decrease seaward in both estuaries, but are relatively high at bay stations. Kaolinite is the most dominant clay mineral in the upstream of both rivers. Smectite increases seaward in both estuaries and is abundant in the bay. Upstream stations of Mandovi, where ore deposits are stored on the shore, exhibit high Fe, Mn, total rare earth elements (∑REE), and middle REE- and heavy REE-enriched patterns. Channel stations of both estuaries exhibit middle REE- and light REE-enriched patterns, which gradually changed seaward to middle REE- and heavy REE-enriched patterns. Canal stations exhibit the highest concentrations of major and trace metals. High metal/Al ratios occur at stations in the upstream of Zuari and at the confluence of canals in the Mandovi estuary. Enrichment factors of metals indicate that Mn is significantly polluted while other metals are moderately polluted. The δ ¹³C and δ ¹⁵N of organic matter indicate that the terrigenous organic matter at the upstream is diluted seaward by marine organic matter. Organic matter at bay stations is largely marine and altered-type. The compositions of SPM are controlled by the particulates from ore dust, the geology of the drainage basins, and the physicochemical processes in the estuaries. Particulates resuspended from the bay are dominated by ore dust, which are advected into the channels of both estuaries during the lull periods of the monsoon.     

Preliminary investigation of sensitive biomarkers of trace metal pollution in mussel (Mytilus galloprovincialis) from Izmir Bay (Turkey)

The aim of this study was to identify possible relationships between biochemical- superoxide dismutase (SOD), glutathione peroxidase (GPx), thiobarbituric acid reactive substances (TBARS) of mussels (Mytilus galloprovincialis) and chemical (Hg, Cd, Pb, Cr, Cu, Zn, Mn and Fe) contaminants from relatively clean area (Middle Bay) and heavily polluted area (Inner Bay) of the Izmir Bay. Sampling of mussels was performed in the beginning of May 2004. Mussel digestive glands have been used for biochemical assays. Trace metal content was determined by atomic absorption spectrophotometer using standard procedures. Metal contents in mussels collected at polluted site increased compared to the middle part of the bay. While there was a positive correlation between metals and SOD enzyme activity, there was a negative correlation between metals and GPx enzyme activity. An increase was observed in SOD enzyme activity and a decrease of GPx enzyme activity at the inner part of the bay.     

Accumulation and biological effects of metals in wild rats in mining areas of Zambia

The lead–zinc (Pb–Zn) mine in Kabwe City and the copper–cobalt (Cu–Co) mine in the Copperbelt Province are major mining areas in Zambia. To examine the effects of metal pollution on wildlife, wild black rats (Rattus rattus and Rattus tanezumi) were captured in Kabwe and Chingola (in the Copperbelt Province), and in Lusaka (a noncontaminated site). Wild black rats in Kabwe accumulated significantly higher concentrations of Pb and Cd in various organs than rats from Lusaka. In Chingola, significantly higher concentrations of Cu, Co, Pb, and Cd were accumulated in wild black rats than in rats from Lusaka. These results were in accordance with metal accumulation patterns in soil. From toxicological aspects, concentrations of Pb and Cd in rats were generally low. However, metallothionein-1 (MT-1) and metallothionein-2 (MT-2) mRNA expression levels in wild black rats from Kabwe were significantly higher than those in rats from Lusaka. A generalized linear model (GLM) showed that concentrations of Zn and Cu had positive effects on the MT-1 and MT-2 mRNA expression. These results suggest that wild black rats in Zambian mining sites were exposed to metals that accumulated in their organs, causing biological responses such as MT mRNA induction. GLM indicated that heme oxygenase-1 (HO-1) mRNA expression could be a marker for Cr exposure.     

Biomonitoring study of heavy metals in biota and sediments in the South Eastern coast of Mediterranean sea, Egypt

Concentrations of Cd, Cu, Co, Zn, Mn and Fe were determined in biota and sediment samples collected from the Eastern Harbour and El-Mex Bay in the Mediterranean Sea, Egypt. The levels of Cu, Co, Zn, Mn and Fe in the macroalgae, Ulva lactuca, Enteromorpha compressa (green algae) and Jania rubens (red algae), recorded high concentrations except for Cd. Moreover, Fe was the most predominant metal in the seaweed. The two species of bivalves, Donax trunculus and Paphia textile, showed different amounts of metals in their tissue. The abundance of heavy metal concentrations in the mussel samples was found in the order Fe> Zn> Mn> Cu> Co> Cd and Fe> Zn> Mn> Cu> Cd> Co, respectively for the two species. The metals concentrations were generally higher compared with the previous studies in mussels from the same area. The levels of metals accumulated in the investigated fish samples, Saurida undosquamis, Siganus rivulatus, Lithognathus mormyrus and Sphyraena sphyraena, were higher than those of Marmara Sea (Turkey), for Co and Cd and lower for Cu, Zn, Mn and Fe. El-Mex Bay having the highest metals concentration in sediments as their order of abundance were Fe> Zn> Mn> Cu> Cd> Co. Nevertheless, a high variability in the metal levels occurs among the studied algae and biota and also between the investigated Harbour. A significant correlations (p < 0.05) were found for each of Zn and Fe in P. textile and of Co in D. trunculus relative to their concentrations in surficial sediments.     

One-year monitoring survey of organic compounds (PAHs, PCBs, TBT), heavy metals and biomarkers in blue mussels from the Arcachon Bay, France

Marine mussels Mytilus sp. were transplanted on a monthly basis in cages over one year to oyster farms and harbours in the Arcachon Bay (France) in order to assess the water quality of the bay. Contaminant levels (organotin compounds, trace metals, PCBs and PAHs) were measured in tissues of transplanted mussels and mussels from a reference station, along with physiological parameters of the mussels (condition indexes, lipid content and dry weight). Four biomarkers (AChE: acetylcholinesterase activity, GST: gluthathione S-transferase activity, CAT: catalase activity and TBARS: thiobarbituric acid-reactive substance content) were also monitored. The remote stations monitored (oyster parks) exhibited no accumulation pattern of pollutants. Their respective concentrations therefore constitute a background level of the contamination in the bay ([TBT]= 30 ng Sn g(-1) dw, [SigmaHAPs]= 100 ng g(-1) dw, [SigmaPCBs]= 35 ng g(-1) dw). The elevated chemical contamination of the largest harbour of the bay, the Arcachon harbour, can be interpreted in terms of persistence of organotin compounds ([SigmaOTs]= 1500-2000 ng Sn g(-1) dw) and PAHs ([SigmaHAPs]= 4500-5000 ng g(-1) dw) in sediments and, to a lesser extent, of direct inputs of copper ([Cu]= 20 microg g(-1) dw in harbours versus 7 in oyster parks) and petrogenic PAHs ([methylphenanthrenes]= 1600 ng g(-1) dw in the dockyard versus 170 at the gas stations), related to the use of copper-based antifouling paints and to dockyard activity, respectively. However, the Arcachon Bay presents a low contamination level by PCBs and metals, including harbour stations. Furthermore, higher levels of other PAHs (particularly alkyl PAHs such as methylphenanthrenes/1600 ng g(-1) dw) not included in the 16 PAHs from the EPA priority list (usually studied in biomonitoring programmes/1500 ng g(-1) dw) in the Arcachon harbour underline the need to integrate these compounds in biomonitoring of highly PAH-polluted areas such as harbours in order to avoid misinterpretation of the biological responses observed. Biomarker responses were not able to discriminate the different chemical contamination levels recorded in the Arcachon Bay and rather reflected changes in environmental factors. Furthermore, the strong intraspecies variability of biological responses could be due to genetic differences of mussels from the Arcachon Bay. It is the first time that such an integrated monitoring is performed in the Arcachon Bay, also taking into account seasonal variations of chemical contents and biomarkers levels in mussel tissues.     

Investigation of heavy metals in sediments and Manila clams Ruditapes philippinarum from Jiaozhou Bay, China

Manila clams (Ruditapes philippinarum) and sediments were collected bimonthly during 2007 at five locations in Jiaozhou Bay near Qingdao, China, to determine heavy metal concentrations and to assess the validation of R. philippinarum as a metal biomonitor. Concentrations of heavy metals in clam soft tissues ranged between 0.75 and 3.31, 0.89 and 15.20, 5.70 and 26.03, 52.12 and 110.33, 10.30 and 72.34, 9.64 and 28.60, and 3.15 and 52.75 μg g^???1 dry weight for Cd, Pb, Cu, Zn, Mn, Cr, and Ni, respectively. Most of the highest values occurred at the northeast bay and the lowest values occurred at the western part. Regarding seasonal variation, relatively high tissue metal concentrations were observed during October or December. A similar pattern was also found in habitat sediments. There was a strong correlation between the concentrations of Cd, Pb, Zn, Mn, Cr, and Ni in soft tissues and surrounding sediments. It is indicated that R. philippinarum could be used as a biomonitor for heavy metal contamination in Jiaozhou Bay.