L. Tolga Gonul

Aliphatic and polycyclic aromatic hydrocarbons in the surface sediments from the Eastern Aegean: assessment and source recognition of petroleum hydrocarbons

Materials and methodsAliphatic and polycyclic aromatic hydrocarbons (PAHs) were determined in surficial sediments from the Aegean Sea in the Eastern Mediterranean in 2008.ResultsTotal aliphatic hydrocarbons (n-C12 to n-C35) ranged from 330 to 2,660 ng g-1 dry weight (dwt), while aromatics (19 PAHs) varied between 73.5 and 2,170 ng g-1 dwt. Total concentrations of both aliphatic hydrocarbons and PAHs ranged from a relatively low to a moderate PAHs pollution compared to other urbanized coastal areas worldwide. PAH consisted mainly of pyrolytic four- to five-ring compounds. Both pyrolytic and petrogenic PAHs are present in most samples, although petroleum-derived PAH are dominant at Izmir Inner Bay (IIB) and Dardanelles Strait, and pyrolytic sources are prevalent in other sampling sites. A high contribution of perylene, a diagenetic originated PAH, to the total penta PAHs was found greater than 70% in Meric River Estuary, Dikili Bay, Candarli Bay, and Gokova Bay sites.ConclusionThe spatial distributions of aliphatic hydrocarbons and PAHs indicated that urban runoff and transport from the continental shelf is the major input pathway of anthropogenic and biogenic hydrocarbons from terrestrial sources in the near-shore area. PAH levels at all sites were below the effects range-low (ERL) and effects range-median (ERM) values except fluorene. The average and maximum fluorene concentrations exceeded ERL, but below ERM, in the IIB. Meanwhile, the concentration levels of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, benzo[a]anthracene, and chrysene were higher than threshold effect level values at the same site, but all these compounds were significantly lower than the probable effect level values. The results indicated that the sediments should have potential biological impact.

Marine organic pollutants of the Eastern Aegean: aliphatic and polycyclic aromatic hydrocarbons in Candarli Gulf surficial sediments.

Aliphatics and PAHs were determined in sediments from the Candarli Gulf in 2009. Aliphatics ranged from 3.88 to 24.7 μg g(-1) while aromatics varied between <4.15 and 405 ng g(-1) (dw). PAHs ranged from a relatively low to a moderate PAHs pollution compared to other urbanized coastal areas worldwide. 3-ring PAHs were most abundant in the sampling area. Both pyrolytic and petrogenic PAHs were present in most samples, although petroleum derived PAHs were dominant at the stations situated near the refinery and petrochemical, metal industry and pyrolytic sources were mainly prevalent in the estuary of Bakircay River. The ratio of UCM to n-alkanes and CPI values in station 6 indicate that the main contribution to petroleum hydrocarbon contamination is via oil and its products. PAH levels at all sites were below the ERL and ERM except fluorene. The results indicated that the sediments should have no potential biological impact except stations 6 and 14.

Occurrence and distribution of organochlorine residues in surface sediments of the Candarli Gulf (Eastern Aegean)

The residual levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in surface sediments collected from Candarli Gulf. Total concentrations of OCPs and PCBs in sediments ranged from 10.2 to 57.3 and 2.8 to 205 ng g⁻¹ dwt, respectively. DDTs in sediments were derived from the aged and weathered agricultural soils in 61% of the sampling stations while 39% of the sites originated from the recent DDT inputs. Their concentrations appeared to be relatively low by global standards and only sediments receiving the impact from the Bakircay River and petrochemical industry approached the sediment quality guidelines for PCBs and DDTs. Based on ERL/ERM guidelines, DDT and PCBs posed ecological risk to the bottom-dwelling consumers.

Heavy Metal Concentrations in Surficial and Core Sediments from Izmir Bay: An Assessment of Contamination and Comparison Against Sediment Quality Benchmarks

The levels of heavy metals were determined in surface and core sediments from the Izmir Bay in 2009. The highest concentrations of As, Cr, Cu, Ni, Pb and Zn were found in the inner bay due to industrial activities. In contrast, maximum levels of Mn, Co, Fe and Al were observed in the outer bay, due to geochemical structure. Cu, Pb, Zn, Ni, As, Cr and Co levels in the upper layer of core sediments were higher than the mean background values of bottom sediments. The enrichment of Cr, Mn, Pb, Zn, Cu and As in the bay seems to be driven by anthropogenic sources. It was found that the sediments in Izmir Inner Bay were generally polluted heavily with Cu, As, Ni, Cr, Pb and moderately with Zn according to the numerical Sediment quality guidelines of the USEPA.

Distribution and sources of polycyclic aromatic hydrocarbons in Cilician Basin shelf sediments (NE Mediterranean)

This study corresponds to preliminary work representing an initial assessment for spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in the Cilician Basin coastal sediments. The concentrations of PAHs in shelf sediments were determined from the three different regions of Cilician Basin (Eastern Mediterranean) in 2011. Concentrations of PAHs were low 5.43-271 ng g(-1) with respect to other coastal sediments in the Mediterranean and these results could be compared with concentrations found in open sea areas. PAH composed mainly of pyrolytic four and five-ring compounds. An abundance of high molecular weight PAHs indicated that atmospheric particles and urban aerosols are the major input route of hydrocarbons in the Cilician and Lattakia Basins. PAH levels were assessed in accordance with numerical Sediment Quality Guideline (SQG) of the USEPA. The results showed that no samples exceeded biological thresholds to pose biological impairments.

Assessment of the effect of environmental pollution in a marina on caged mussels using chemical and genotoxic analysis

ABSTRACT An integrated approach using the contamination levels and DNA damage in mussels (Mytilus galloprovincialis) was applied in order to assess the chemical contamination in a marina (Eastern coastline of Aegean Sea). Mussels, which were harvested from a reference site (Foca), were transplanted into a marina situated along the coast of Izmir Bay. The transplanted mussels were collected at the 14th, 30th and 60th day of the experimental period. Polycyclic aromatic hydrocarbon (PAH) levels (27–51 ng g−1 wet weight) detected in the mussels were similar to the levels detected in other coastal areas of the Mediterranean Sea. The marina’s sediment was found to be contaminated with PAHs (∑PAH = 25 µg g−1) of pyrolytic origin and may become a source of pollution and a threat to the marine environment. In order to assess the DNA damage, the haemolymph and gill cells of the mussels were used for the comet analysis and considered as an indicator of exposure to genotoxic chemicals including 16 PAH compounds and metals. The highest levels of DNA damage expressed as %Tail-DNA (%T-DNA) were observed at the end of the experiment (21.5% T-DNA). The correlation analyses conducted between 2-, 3-, 4-ring PAHs in mussels and %T-DNA in haemolymph and gill cells showed a significant positive correlation. This investigation confirmed that transplanted mussel can be a useful tool to determine PAH contamination in marinas.

Evaluation of the relationship of picoplankton and viruses to environmental variables in a lagoon system (Çakalburnu Lagoon, Turkey)

ABSTRACT Lagoons are defined as wetlands separated from the sea coasts on which they are located and sit between continental and marine aquatic ecosystems. Çakalburnu Lagoon is a coastal wetland on the southern side of the Bay of İzmir. Microorganisms, which are quite sensitive to changes occurring in environmental factors, are commonly used to determine the impact of environmental effects on the functioning of the ecosystem. In this study, variations in the abundance and biomass of picoplankton (Synechococcus spp. and bacteria) and the abundance of viruses, which identify the ecological productivity of the food chain, were seasonally examined by epifluorescence microscopy. Moreover, the microbial abundance and biomass relation over time between the physical and chemical parameters was evaluated. According to our results, the maximum abundance of Synechococcus spp. and viruses was 6.7 × 104 cell/ml and 9.9 × 108 cell/ml in the summer, respectively. Otherwise, the highest level of bacteria was measured at 3.6 × 107 cell/ml in the spring. Based on the principal component analysis and Pearson correlation analysis results, we concluded that total suspended solids, Chl-a, particulate organic carbon and particulate organic nitrogen were the major parameters influencing the observed variability of the lagoon system. Overall, to protect and improve the ecological and microbiological quality of aquatic systems such as lagoons, the necessary monitoring and measurement studies should be conducted in these sensitive areas.

Potential risk assessment of metals in edible fish species for human consumption from the Eastern Aegean Sea

The levels of Hg, Cd, Pb, Cr, Cu and Zn were measured in the tissues of four edible fish species namely: Diplodus annularis, Pagellus erythrinus, Merluccius merluccius and Mullus barbatus, collected from the Turkish Coast of the Aegean Sea. Except for D. annularis, the levels of Cd and Pb in all fish tissues sampled in Aliaga Bay in 2009 were above the tolerable limits according to the Food and Agriculture Organization of the United Nations (FAO). Hg in P. erythrinus and M. barbatus were higher than the maximum permitted limits (FAO), while D. annularis and M. merluccius were lower than the limit for biota in the district of Aliaga. Although the Target Hazard Quotient (THQ) values for Cd, Pb, Cu, Cr, Zn in all fish samples were lower than 1.0, the THQ for Hg levels were higher than 1.0 for most of the samples. According to the THQ values, M. merluccius may be consumed in moderation from Aliaga Bay, while the consumption of M. barbatus and P. erythrinus collected from Aliaga Bay are potentially hazardous to human health due to the Hg concentrations. Fish collected from Izmir Bay can be consumed safely.