著者

川嶋 宗継 小西 吉治郎 奥田 久男 黄瀬 金司 板坂 修 堀 太郎

出版者

滋賀大学

雑誌

滋賀大学教育学部紀要. 自然科学 (ISSN:04886291)

巻号頁・発行日

vol.26, pp.18-25, 1976

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We have investigated at regular intervals about the water qualities of Lake Biwa-ko for the purpose of appreciating the present state of eutrophication. In this year 1976, the water qualities at the eight to nine specific stations were studied on February 25, May 8 and July 19, and the following results were obtained;1) The concentrations of total nitrogen are high at the three periods and over the boundary line for eutrophic lake.2)Total phosphorus is abundant in May, but low in February, which is about 50% of the results in May.3)A significant relationship is found to exist between the concentrations ofchlorophyll a, COD and nutrients, wherever the horizontal or vertical (St.4) of the lake water. This marked correlation seems to be due to the production of phytoplankton occurs regularly in Lake Biwa-ko. In addition, the above finding in this lake as probably in many other lakes supported to the esults reported in the previous paper.