2024 Volume 80 Issue 25 Article ID: 24-25032
Lake Barato is an oxbow lake isolated from the Ishikari River. It is used for fishing and recreation, and there is much interest in its water quality. The water quality of the Lake Barato has improved compared to the period when eutrophication was severe. However, the water quality of Lake Barato has not been studied in detail in recent years. There has also been no assessment of phosphorus release from lake sediments and related metal elements in lake sediments. In this study, lake water and sediment core samples were collected at high frequency to investigate phosphorus release from lake sediments in the Lake Barato. As a result, lake stratification was observed during the summers of 2022 and 2023, and phosphorus release from lake sediments have been enhanced during these periods. During summer, the phosphorus release rate from lake sediments was 7.89 mg-P/m2/d. The lake sediments were rich in iron, which is characteristic of lakes in peatlands. Iron-bound phosphorus was abundant in lake sediments and might contributes to phosphorus release from lake sediments.