Accumulation and distribution of essential and toxic metals in fish and sediment samples from Tekirdağ coastal region, the Marmara sea

The aim of this thesis is to determine the accumulation and distribution of some essential elements and toxic metals (Fe, Cu, Zn, Cr, Mn, Cd, As, Pb, Hg and Ni), which disrupt the endocrine system, in sediment and muscle tissue of the fish from four determined stations of the sea off Tekirdağ province that has the longest coast in the Marmara Sea. Discharge of untreated domestic and industrial wastes into the Marmara Sea through the rivers as a result of rapid population increase around the Marmara Sea, and atmospheric transport and subsequent deposition of heavy metals-containing pesticides that are used in an unconscious, irregular and uncontrolled manner to the Marmara Sea deteriorate the water quality of this sea. The Marmara Sea had 127 species of commercially important fish in the year of 1975, and the decrease of this number to 4-5 today indicates the degree of marine pollution. Fish samples that were caught from four determined stations were brought to the laboratory in ice containers. After washing the samples with distilled water, their length and weight were measured, and they and sediment samples were stored at -30 ° C until analysis. For analysis, samples were defrosted at room temperature, muscle (edible fish part) samples were chopped up with a disposable plastic knife and dried in the oven, and then homogenized in the blender. After the homogenates and sediment samples were dried in the oven and burned in the microwave oven, concentrations of essential and toxic metals were determined with the ICP-OES equipment. Except Cu, the concentrations of Fe, Zn, Cr, Mn, Cd, As and Ni in fish were found to be above the limits imposed by FAO, WHO and TGK (Turkish Food Codex). Pb and Hg could not be determined because they were substantially below the measurement limits. Sediment samples differed in each region in terms of elements analyzed, in that according to EPA sediment quality criteria sediment of Şarköy was classified as moderately contaminated with Fe, sediments of Şarköy and Marmara Ereğlisi were classified as slightly contaminated with Mn, sediment of central district was classified as slightly contaminated with Cr, sediments of Şarköy and central district were classified as moderately contaminated with Ni, and sediment of Şarköy was classified as extremely contaminated with As and Cd. Hg was not detected in any sediment sample. Sediments of four stations were uncontaminated with Pb, Cu, and Zn. Key words: Sediment, Fish, Essential Elements and Toxic Metals, ICP-OES, 2019, 64 Pages