中海本庄工区における植物プランクトンの種類組成と現存量の季節変化

We studied seasonal changes in species composition and abundance of phytoplankton at Honjou area of the brackish Lake Nakaumi from November 1996 to December 1998. Samples were monthly collected from six study sites. Phytoplankton identified in the present study were 26 taxa in total, 12 of Bacillariophyceae, five of Chlorophyceae, four of Dinophyceae, three of Cyanophyceae, one of Cryptophyceae and one of Euglenophyceae. The phytoplankton community of Honjo area was mainly composed of brackish species or species of inner bay, which were similar to those at the central part of Lake Nakaumi. Prorocentrum minimum and Cyclotella spp. dominated in Honjo area. P. minimum bloomed in April 1997, May and December 1998. Cyclotella spp. bloomed in October 1997. Freshwater species of green and blue-green algae were very rare throughout this study, and species number of them was less than that in the central part of Lake Nakaumi.