The Distribution of mercury (Hg) in İzmir Bay

The aim of this thesis is to assess mercury pollution in İzmir Bay. Total mercury concentrations were determined in seawater, particulate matter, sediment, plankton and in tissues of the organisms. The range of reactive and total mercury in seawater were 5-40 ng/1 and 5-43 ng/1, respectively. The mercury content of particulate matter in İzmir Bay ranged between 1.24-5.76 ug/g in winter, 0.14-2.48 ug/g in summer. Mercury concentrations in particulate matter were higher due to pluvial inputs in winter. The concentrations of total mercury in surface sediments of Izmir Bay ranged between 0.04 and 0.63 ug/g (dry weight). The highest mercury levels were observed in the Inner Bay. Slightly lower values of mercury were found in the Outer Bay. Lowest mercury levels were obtained in the Middle Bay. Sediment results show that mercury concentrations in sediments are enriched as compared to seawater by a factor of 4000 to 63000. Plankton serves as food for the higher trophic levels and therefore mercury concentrations in plankton were also studied. The total mercury contents in planktons were found 0.14-0.59 ug/g (dry weight). The highest mercury levels in plankton were measured in the Inner Bay. The concentrations in the Middle Bay was considerably lower than the values in the Outer Bay. The concentration factors in plankton ranged between 14000-59000 relative to seawater of the bay. The study offish muscle tissue is one of the means for investigating the amount of mercury entering the human body by food chain enrichment and therefore has beeninvestigated in this study. The correlation coefficients show a positive relationship between the mercury levels in the Mullus barbatus, Merluccius merluccius with total length and total weight. The distribution of mercury in tissues of red mullet (Mullus barbatus), european pilchard (Sardina pilchardus), hake (Merluccius merluccius), sole (Solea vulgaris vulgaris), annular sea bream (Diplodus annularis), red pandora (Pagellus eryihrinus), prawn shrimp (Penaeus kerathurus) and long-finned squid (Loligo vulgaris) were determined (0.03-0.54), (0.02-0.03), (0.03-0.10), (0.01-0.26), (0.10-0.56), (0.32- 0.91), (0.01-0.64), (0.14-0.34) ug/g (wet weight), respectively. The concentration factors in fish ranged between 1000-91000 relative to seawater of the bay. The highest concentration factors were observed in the fish muscle. Gediz River and inactive mercury mining sites at Karaburun were the most important inputs of mercury to the outer bay. The biggest mercury load in particulate matter was carrying to the Izmir Bay by Gediz River. In the "Dökü Sahası" areas, higher mercury concentrations were observed in the particulate matter, sediment and plankton. From the results, it was showed that mercury concentrations should be measured in all fishes catched from the small bay and gulf near the city.in a monitoring programme. Türkiye also must be necessary to determined the maximum permissible mercury concentrations for fishes in the seas.