"Aoko", the water-bloom of blue-green algae, of Lake Biwa in summer of 1990

Abstract

The water-bloom of blue-green algae (so-called "Aoko" in Japanese) occurred in late August of 1990 on the littoral zone of Otsu City, the southernmost shore of Lake Biwa. The water-bloom was composed of the following blue-green algae: Microcystis wesenbergii (63.5%), Anabaena spiroides var. crassa (14.4%), Oscillatoria tenuis (12.0%), Microcystis aeruginosa (6.6%), Anabaena affinis (3.5%). Oscillatoria kawamurae was found for the first time from Lake Biwa.