Mercury in the Environs of Kagoshima Bay.

Abstract

Mercury contents of samples of sea water and fish from Kagoshima Bay, sediments in rivers, and the surface soil from the area surrounding a waste incinerator in the city of Kagoshima were measured to search for the source of mercury in Kagoshima Bay. The results obtained were as follows: 1) Mercury contents of sea water samples at 26 stations in Kagoshima Bay ranged from 6.3 to 19.7 ng/l. When the 26 stations were classified into four areas, the entrance, the middle and the interior of the Bay, and the water around the Sakurajima area, mercury contents of the samples from the last area were significantly higher than either at the entrance or in the interior of the Bay. 2) Mercury contents in the cardinal fish, Apogon notatus, were significantly higher than those in either the dragonet, Callionymus lunatus, or the sillaginoid, Sillago japonica. Mercury contents of fish from the Ushine coast station, the innermost part of the Bay, were significantly higher than those from the other collecting stations. Moreover, significantly interactions between the species of fish and the sampling stations were detected, and mercury contents of cardinal fish from Ushine coast station were 6.7-fold higher than those from the sampling station at the mouth of the Shinkawa river. 3) River sediments obtained 1 km from the mouth of each river contained from 4 to 96 micrograms/kg of mercury. Mercury contents of the river sediments from the Wada river were higher than those from the other rivers examined.(ABSTRACT TRUNCATED AT 250 WORDS)