摘要：Lake Koetoi-Onuma is a low-lying brackish lake in the northernmost part of Hokkaido, Japan. There are few limnological or biological studies done on this lake because it lies in an inconvenient location. The authors investigated the diatom flora of the lake and compared the results with those of Tanaka (1992). The variation found supports that the salinity of the lake is on an upward trend in these past 40 years.
