Aynur Kontas

Trace metal and organochlorine residue levels in red mullet (Mullus barbatus) from the eastern Aegean, Turkey.

The levels of trace metals and organochlorine residue were determined in red mullet (Mullus barbatus) in the framework of a MED-POL II Project for the Aegean Sea during 1994-1998. Samples were analyzed seasonally from July 1994 to January 1998. The concentrations of trace metals found varied with Hg: 16-200 microg kg(-1), Cd: 0.57-4.5 microg kg(-1) and Pb: 40-207 microg kg(-1) wet weight. The order of trace metal concentrations found in Mullus barbatus was Pb > Hg > Cd. Correlation coefficients were calculated between Hg, Cd, and Pb concentrations and fork lengths to be Hg: 0.5852, Cd: -0.081, Pb: 0.5823, respectively. Cadmium levels are lower than the results in fish tissues reported from Mediterranean regions. The results of organochlorine residues measured varied between Aldrin: 0.10 and 0.61 microg kg(-1), t-DDD: 0.86 and 4.5 microg kg(-1) and t-DDE: 10 and 18 microg kg(-1) wet weight. Correlation coefficients for measured organochlorine residues and fork lengths are Aldrin: 0.6422, t-DDD: 0.2237 and t-DDE: 0.5484. The levels of mercury, lead and organochlorine residues are similar to the results in fish from Mediterranean countries.

Monitoring of eutrophication and nutrient limitation in the Izmir Bay (Turkey) before and after Wastewater Treatment Plant.

The distribution of inorganic nutrients and phytoplankton chlorophyll-a was investigated and N/P ratios were determined in Izmir Bay during 1996-2001. The average concentrations showed ranges of 0.01-0.19 and 0.01-10 microM for phosphate-phosphorus; 0.11-1.8 and 0.13-27 microM for (nitrate+nitrite)-nitrogen, 0.30-4.1 and 0.50-39 microM for silicate and 0.02-4.3 and 0.10-26 microg l(-1) for chlorophyll-a in the outer and middle-inner bays, respectively. The results are compared with the values obtained from the relatively unpolluted waters of the Aegean Sea. The N/P ratio is significantly lower than the assimilatory optimal (N/P=15:1) in conformity with Redfields ratio N/P=16:1. Nitrogen is the limiting element in the Izmir Bay. Phosphate, which originates from detergents, is an important source for eutrophication in the bay, especially in the inner bay. In early 2000, a Wastewater Treatment Plant (WTP) began to treat domestic and industrial wastes. This plant treats the wastes about 60% capacity between 2000 and 2001. The sampling periods cover before and after treatment plant. Although the capacity of wastewater plant is sufficient for removal of nitrogen from the wastes, it is inadequate for removal of phosphate. This is also in accordance with the decreasing N/P ratios observed during 2000-2001 (after WTP) in the middle-inner bays.

Sediment concentrations of heavy metals in the Homa Lagoon (Eastern Aegean Sea): assessment of contamination and ecological risks.

The concentrations of heavy metals and organic carbon in sediment of the Homa Lagoon which is one of the most productive lagoons and commercial important active fish trap in the Eastern Aegean Sea, were investigated in order to describe the temporal and spatial distributions of metals. These results were used to evaluate possible ecological risks that could be a problem for the environment of the lagoon in the future. Sediments were enriched with Cr, Ni and considered as heavily polluted per the SQG. The C(f) of Ni and Cr were presented moderate level of contamination in this area. The C(d) levels indicated moderate degree of contamination at station B, C, D and E due to agricultural drainage water, industrial and domestic wastewater, are transported by the Gediz River. Sediments from Homa Lagoon were most toxic for Ni due to exceedances of the TEL and PEL values.

Heavy metals contamination levels at the Coast of Aliağa (Turkey) ship recycling zone

Aliağa Bay is one of the most important maritime zones of Turkey where shipping activity, shipbreaking industry, steel works and petrochemical complexes exist together. Concentrations of heavy metals and organic carbon in sediment of the Aliağa Bay were investigated to evaluate an environmental risk assessment from metals contamination in 2009-2010. Comparison of the metal concentrations with average shale and Mediterranean background levels revealed that most of the samples from the Aliağa were polluted with Hg, Cd, Pb, Cr, Cu, Zn, Mn and Ni. It was found that Hg, Pb, Cu, Zn and Ni levels in Aliağa Bay exceeded the PEL values. Sediments, contaminated with Pb, Cr, Cu, Zn and Ni were considered as heavily polluted per the SQG.

Evaluations of heavy metal pollution in sediment and Mullus barbatus from the Izmir Bay (Eastern Aegean) during 1997-2009.

Izmir Bay is one of the great natural bays of the Mediterranean. The surface sediment and fish samples were collected during 1997-2009. The sediment concentrations of inner bay showed significant enrichments during sampling periods. Outer and middle bays exhibited low levels of metal enrichments except the estuary of Gediz River. The concentrations were generally higher than the background levels from the Mediterranean and Aegean except Cd and Pb levels gradually decreased. Metal EF is used as an index to evaluate anthropogenic influences of metals in sediments. Maximum metal enrichment was found for Hg in the outer bay, while Pb indicated maximum enrichment in the middle-inner bays. Metal levels were evaluated in sediments in accordance with the numerical SQG of the USEPA. The levels of fish tissues were lower than the results reported from polluted areas of the Mediterranean. The highest BAFs were detected for Hg and Cd in fish.

Polycyclic aromatic and aliphatic hydrocarbons pollution at the coast of Aliaga (Turkey) ship recycling zone.

Aliağa Bay is one of the most important maritime zones of Turkey where shipping activity, shipbreaking industry, steel works and petrochemical complexes exist together. Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons in sediment of the Aliağa Bay were investigated to evaluate an environmental risk assessment from PAHs contamination in 2009-2010. Aliphatic and PAHs diagnostic ratios were showed to be mainly petroleum-originated and pyrolitic contaminations, respectively. The TEL/PEL analysis suggests that Aliağa sediments were likely to be contaminated by acutely toxic PAH compounds.

Eutrophication in İzmir Bay, Eastern Aegean

The polluted waters of Izmir Bay were studied to measure the variations of biochemical and physical characteristics monthly or three‐monthly. The spatial and temporal changes of nutrients (nitrate, nitrite, and ortho phosphate) and chlorophyll‐a, temperature and salinity in the bay were monitored during the period of February 1990 ‐ December 1992. The evaluated results were compared with the results obtained from the relatively unpolluted waters of the Aegean Sea. Eutrophication of the inner bay has already started, spreading progressively to the rest of the bay. The degree of eutrophication in the bay was assessed. The concentration of nutrients ranged between 0.21–2.51 μg‐at l‐1 for PO4‐P; 0.44–4.20 μg‐at l‐1 for NO3‐N; 0.11–3.50 μg‐at l‐1 for NO2‐N. Chlorophyll‐a concentration is between 0.7–39.1 μg l‐1 and estimated primary productivity in the bay is 7–10 times higher than the offshore production in the region. The main reason for high primary production is the high terrestrial input. As expected tota...

Spatial variations in polycyclic aromatic hydrocarbons concentrations at surface sediments from the Cyprus (Eastern Mediterranean): relation to ecological risk assessment.

The objective of the present study was to evaluate the distribution, sources, origins, and environmental risk assessment of polycyclic aromatic hydrocarbons (16 US EPA priority pollutants) pollution in 23 surface sediments from Cyprus coast. The mean total polycyclic aromatic hydrocarbons (PAHs) concentrations in the sediments from Gemi Konagi, Girne and Gazi Magusa areas were found 47, 52 and 50 ng/g, respectively. Molecular ratios and principle component analysis indicated that PAH pollution originated mainly from fossil sources, with higher pyrolytic contributions. The 2-3 ring PAHs were dominant in Cyprus sediments. Concentrations of PAHs observed in this study were compared with available soil quality guidelines and the concentrations were lower than the guideline values. The guideline values suggested that the Cyprus sediments were likely to be not contaminated by toxic PAH compounds.

Dissolved and dispersed petroleum hydrocarbons in the Aegean Sea

The distribution and transportation of Dissolved and Dispersed Petroleum Hydrocarbon (DDPH) were investigated in the Aegean Sea with the hydrodynamics of the water masses of the region. It is clear that distribution of this pollutant is strongly affected by physical dynamics of environment. The data were collected during cruises in November 1994, in the framework of National Marine Measurement and Monitoring Programme in the Aegean Sea. In the present study additionally the Chlorophyll‐a was measured fluorometrically and there is good correlation between petroleum hydrocarbon and chlorophyll‐a in the Aegean Sea. DDPH data was used to search origin of hydrocarbons: biogenic or non biogenic.

Spatial Distribution Patterns, Sources of Heavy Metals, and Relation to Ecological Risk of Surface Sediments of the Cyprus Northern Shelf (Eastern Mediterranean)

In this study, the spatial distribution of metals and the sources of metal pollution were investigated along the Northern Shelf of Cyprus (Mediterranean Sea). The concentrations of heavy metals and organic matter were measured in sediments collected from the Gemi Konagi, Girne, and Gazi Magusa areas. Measured metal values were compared with Mediterranean background concentrations. Cu and Zn concentrations at the Gemi Konagi area and all of the Cr values were higher than Mediterranean backgrounds. The metal levels were evaluated by the enrichment factor (EF), contamination factor (Cf) and degree of contamination (Cd). EF results indicated that heavy metal sources were probably originated from natural processes and mining activities. The Cf values of Hg indicated low contamination. The Cd (degree of contamination) values for all heavy metals also showed a low degree of contamination at the study area. Metal levels were also compared with the numerical Sediment Quality Guidelines (SQG) for an environmental risk assessment. Results showed that sediments were classified as heavily polluted by Cu and moderately polluted by Zn at Gemi Konagi and heavily polluted by Cr and Ni contamination at all sampling areas per the SQG.