ABSTRACT

The size distribution and the aggregation state of particulate organic matter and particulate iron were microscopically observed by the application of histological dyeing method. They were seriously affected by the seasonal water circulation in Lake Haruna. From the results, the formation and the change of particulate iron were suggested. Iron-organic aggregates were observed both in the lake and in the sea, and the significance of their distribution was discussed in relation to the sedimentation of iron and the formation of organic aggregates.