Heavy metal pollution in sediments and mussels: assessment by using pollution indices and metallothionein levels.

In the present work, the concentration of eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) was determined in the sediments and transplanted and native mussels (Mytilus galloprovincialis). The study was conducted in Turkish marinas, shipyards, and shipbreaking yards. The effect of metal pollution was evaluated by determining the levels of metallothionein (MT) in the mussels. The extent of contamination for each single metal was assessed by using the geoaccumulation index (I geo) and enrichment factor (EF). Whereas, to evaluate the overall metal pollution and effect, the pollution load index (PLI), modified contamination degree (mC d), potential toxicity response index (RI), mean effects range median (ERM) quotient (m-ERM-Q), and mean PEL quotient (m-PEL-Q) were calculated. The influence of different background values on the calculations was discussed. The results indicated a significant metal pollution caused by Cu, Pb, and Zn especially in shipyard and shipbreaking sites. Higher concentrations of MT were observed in the ship/breaking yard samples after the transplantation.

Determination of selected antibiotics in the Istanbul strait sediments by solid-phase extraction and high performance liquid chromatography.

Surface sediments from 12 different locations of the Istanbul Strait and Marmara Sea, Turkey were analysed for five antibiotics belonging to two different groups of widely used pharmaceuticals, tetracyclines (TCs) and fluoroquinolones (FQs), by solid-phase extraction and high performance liquid chromatography. These two groups of antibiotics, mainly used to prevent or treat illness for humans as well as for animals, are frequently detected in the effluent of municipal sewage plants, in the aquatic environments and in soils after being spread by liquid manure. The results of analysis revealed that measured concentrations of individual antibiotics were significantly different depending on sampling location. Chlortetracycline (CTC) was not detected in any of the samples. High concentrations were mainly found in urbanized regions of the Strait. The concentrations of the two tetracyclines ranged from not detectable to 27.3 µg kg(-1) in freeze-dried marine sediments. Comparable results were obtained for the two fluoroquinolones with concentration levels from 1.3 µg kg(-1) up 34.1 µg kg(-1). This study is the first attempt to show the contamination degree of the Istanbul Strait sediments by emerging contaminants. Particular concern should be given concerning their potential side effects caused by the frequent consumption of mussels and fishes captured in the Istanbul Strait.

Distribution of organochlorine pesticides in sediments and mussels from the Istanbul Strait.

This study was conducted to determine the status and trends of organochlorine pesticide (OCP) compounds in the sediment and mussel samples collected along the Istanbul Strait and from the coasts of an island in the Marmara Sea. The total concentrations of OCPs were found in the range of 40-13,852 pg g(-1) dry weight for sediments and 5,195-12,322 pg g(-1) wet weight for mussels. The levels of OCPs in both sediments and mussels were dominated by DDTs and HCHs; ß-HCH, 4,4(')-DDD and 4,4(')-DDE were the major pollutants. The degree of sediment pesticide contamination was more severe in the inner part of the strait. OCP concentrations in sediments and mussels were compared with the sediment guideline values and legal limits for human health, respectively. The results showed that OC pesticide contamination in the strait might not pose a serious threat to the health of the marine inhabitants at most of the stations.

Monitoring of organic pollutants in marine environment by semipermeable membrane devices and mussels: accumulation and biochemical responses.

This study involves the monitoring of organic pollutants using transplanted mussels (Mytilus galloprovincialis) as bioindicator organisms and semipermeable membrane devices (SPMDs) as passive samplers. Mussels and SPMDs were deployed to marinas, shipyards and shipbreaking yards on the coastal area of Turkey and retrieved after 60 days. Polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and organochlorine pesticide (OCP) compounds were analysed with high-resolution GC-MS. Total PAH concentrations in SPMDs and mussels ranged from 200 to 4740 ng g sampler-1 and from 7.0 to 1130 ng g-1 in wet weight (ww). PCB and OCP concentrations in SPMDs changed between 0.04-200 and 4.0-26 ng g sampler-1, respectively. The highest PCB (190 ng g-1 ww) and OCP (200 ng g-1 ww) concentrations in mussels were measured at shipyard stations. A strong correlation was observed between the PAH and PCB concentrations in SPMDs and mussels. Enzyme assays (acetylcholinesterase, ethoxyresorufin-O-deethylase, glutathione S-transferase, glutathion reductase and carboxylesterase activities) were performed as biomarkers to reveal the effects of pollution on the mussels. There was no clear relationship found between the enzyme levels and the pollutant concentrations in mussels. Integrated biomarker responses were calculated to interpret the overall effect of pollutants.

Evaluation of butyl rubber as sorbent material for the removal of oil and polycyclic aromatic hydrocarbons from seawater.

Ecological disasters resulting from oil spills have created a great need to find more efficient materials for oil spill cleanup. This research highlights the use of a novel macroporous polymeric material based on butyl rubber (BR) as a sorbent in an oil spill cleanup. The sorption capacity of BR for crude oil and petroleum products is 15-23 g g(-1) as compared to the value of 10-16 g g(-1) obtained using a nonwoven polypropylene (PP), a widely used commercial oil sorbent. BR sorbent is reusable after simple squeezing and its continuous sorption capacity for crude oil is 7.6 g g(-1) in each cycle, about 3 times the capacity of the PP sorbent BR sorbents also remove efficiently polycyclic aromatic hydrocarbons (PAHs) such as acenaphthene and pyrene from seawaters. The results suggest that the rubber sorbents are a better alternative to the widely used PP sorbents by improving the efficiency of oil sorption and the reusability of the sorbent.

Bioconcentration and phototoxicity of selected PAHs to marine mussel Mytilus galloprovincialis.

This study assessed the sensitivity of Mytilus galloprovincialis (Mediterranean mussel) to UV-induced toxicity of pyrene, phenanthrene, fluoranthene and chrysene. Mussels were exposed to two different polyaromatic hydrocarbon (PAH) concentrations within the solubility limits for 7 days, after which the filtration rate and the blood cell stability of the mussels were determined to quantify the effects of PAHs. Mussel tissues were analysed at the end of the experiments to determine the degree of bioaccumulation of PAHs and in order to make quantitative body-burden/effect links. The differences between the tissue residue based effective concentration (TEC(20)/TEC(50)) values before and after ultraviolet (UV) exposure provided a measure of phototoxicity of the bioaccumulated PAHs. Out off the biomarkers applied, Neutral Red Retention (NRR) results showed that the most toxic compound is chrysene in the absence of UV. The NRR technique was found more sensitive compared to Fitration Rate (FR) technique. The toxicities of chrysene, phenanthrene and pyrene were enhanced by UV, while fluoranthene was toxic in the absence of UV lighting and its toxicity did not change by UV application.

Photoinduced toxicity of selected PAHs to the marine microalga Phaeodactylum tricornutum.

In this study, the effects of different concentrations of pyrene, phenanthrene, fluoranthene, and chrysene within the solubility limits of the chemicals on marine microalgal species of Phaeodactylum tricornutum were examined under UV-A and UV-B lights by application of batch toxicity tests. The algal species were also exposed to the individual PAHs under cool-white fluorescent bulbs in the same laboratory conditions in order to compare the results with the responses of UV-exposed organisms. EC50 values calculated with the trimmed Spearman Karber method demonstrate that the UV light dramatically enhances the toxicity of the selected model PAHs. In most cases, the magnitude of increase in PAH toxicity was directly related to the concentration of individual PAHs and the duration of UV-lighting.

Comparison of several toxicity tests applied to complex wastewaters and mussel biomarkers in receiving waters.

In this study, the complex wastewaters/effluents discharged to coastal regions of Turkey and Greece were sampled, and various toxicity tests were applied. The bioassays used included the assessment of the luminescence inhibition of the bacterium Vibrio fisheri, the photosynthesis inhibition (14C uptake rate) and growth inhibition of the algal species Phaeodactylum tricornutum, and the mortality of the crustacean Artemia franciscana and rotifer Brachionus plicatilis. Additionally, "neutral red retention" and "filtration rate" sublethal biomarker techniques were performed by utilizing the mussel species Mytilus galloproviancialis, inhabiting the points of discharges in Turkey. All discharges tested were found to be acutely toxic to P. tricornutum and slightly toxic to V. fisheri, A. franciscana, and B. plicatilis. Test results showed that the 14C uptake rate toxicity test was the most sensitive one among the other bioassays. The biomarker results showed that the health status of mussels in the coastal areas decreased significantly, indicating the pollution of the receiving waters in Turkey. The conclusions drawn highlight the necessity for an intesive ecotoxicological monitoring scheme that will incorporate the most suitable bioassays and biomarkers to adequately contribute to the upgrading and maintenance of the ecological quality of the coastal waters in Greece and in Turkey.