RESUMEN
The extent of organochlorine pesticides (OCPs) contamination in Manyas Lake (Bird Lake) and its tributary rivers and streams which is situated near the South-eastern coasts of the Marmara Sea in Turkey was investigated. Residues of OCPs in surface water and sediment samples were analysed by gas chromatography equipped with electron capture detector. The total OCPs concentration (SOCPs) in water and sediment samples ranged from 1.43 to 8.6 µg l-1 and from 17.05 to 39.14 ng g-1, respectively. According to the concentrations and detection frequencies, HCHs, DDTs, heptachlor and heptachlor epoxide were the most dominant compounds among the OCPs. The results showed that Manyas Lake was still contaminated by organochlorine pesticides and their residues despite bans on the production and usage over a long time.
RESUMEN
The accumulation of some heavy metals such as Pb, Cd, Cu and Ni was determined in water sediment and fish samples (Albumus escherichii, Cyprinus carpio and Silurus glanis) collected from Nallihan Bird Paradise (NBP) and its vicinity (Sariyar Dam). The results showed that these metals are found widespread throughout the study area, but metal concentrations in the water samples are below the detection limits (BDL). Pb, Cd, Cu and Ni contamination were determined in sediments and in fish tissues (muscle and liver) and it was seen that they were accumulated and biologically magnified in lish tissues. Metal concentration levels in sediment samples were higher than that of water and fish tissues. The highest amount of metal concentrations in sediment samples among seven stations were determined in Usakbuku (Pb: 0.49 ppm), Sakarya River (Cu: 1.12 ppm) and Sariyar (Ni: 0.77 ppm). Unlikely to the other stations, no metal residues were determined in the sediment samples ofAladag Creek Station.