琵琶湖南湖におけるミクロキスチスの優占的発生と水質, 気象諸要因との関係 Relationship between the Dominant Occurrence of Microcystis aeruginosa and Water Quality or Meteorological Factors in the South Basin of Lake Biwa
In the south basin of Lake Biwa, <i>Microcystis aeruginosa</i> dominantly occurred and the water blooms were formed at the limit area in late summer of 1983, 1987, 1988, 1990, and 1994. The relationship between the dominant occurrence of <i>M. aeruginosa</i> and water quality and the meteorological condition in the south basin of Lake Biwa was examined, referring to data from Shiga Prefecture and the meteorological Agency.<br>The changes of water quality in the south basin in early September of 1980-1994 showed a remarkable fluctuation of TP (total phosphorus), DIN (dissolved inorganic nitrogen), DIP (dissolved inorganic phosphorus), DIN:DIP, TN (total nitrogen):DIN, and TP:DIP ratios, and <i>M. aeruginosa</i> usually occurred in the water with comparatively low DIN:DIP ratio.<br>The comparison of each average water quality with the dominant species of phytoplanktons in early September of 1980-1994 showed that <i>M. aeruginosa</i> dominantly occurred in the waters with low DIN, DIP, and DIN:DIP ratio and high TN: DIN and TP:DIP ratios. The species occurred in the years with the meteorological conditions of high air temperature, long sunshine time, and comparatively low rainfall (precipitation) during August. These features of <i>M. aeruginosa</i> were contrasted remarkably with those of <i>Rhodomonas</i> sp.
日本水産学会誌 63(4), 531-536, 1997-07-15