Abstract
There is little information regarding the presence of methylmercury in the sea water, while the total mercury levels in the sea water have been determined by many investigators. Therefore, the origin of methylmercury in the marine ecology still remains obscure. Thus, in order to clarify if there exists appreciable amount of methylmercury in the sea water, we have developed a method for concentrating and measuring trace amount of methylmercury and determined the methylmercury levels in both offshore and inshore area around Japan archiperago.
When the sea water was filtered through the membrane filter (pore size 0.45, m), methylmercury concentration was about 0.2ng/L with certain variances depending on an area at which the water was sampled. On the other hand, methylmercury concentration in the suspended substances (SS) (mostly phyto-plankton) remaining on the filter showed approximately constant value of 0.2-0.3 ng/SS /L. Methylmercury concentration per unit mass of SS was 104-105 times more than of the filtered sea water.
