ABSTRACT

Mercury and organic nitrogen were determined in sediment cores taken from the Okhotsk Sea and Funka Bay in northern Japan. The concentrations of mercury and organic nitrogen in the cores decrease from the surface to a nearly constant value below 20-50cm depth. Mercury is strongly correlated with organic nitrogen in each core, showing association of mercury with organic matter. Copper, zinc, iron and lead were also determined in some cores but showed no systematic variation with depth. Methylmercury both in interstitial waters and in solid phases was determined for some Funka Bay cores. The profiles appear to suggest that the mercury is lost from the sediments during early diagenesis by forming methylmercury or its sulfur derivatives.