The phytoplankton community of Yenicaga Lake (Bolu, Turkey)
The composition and succession of phytoplankton community of a lake are described over an approximate two-year period. Eighty-one species were recorded. Diatoms dominated during early spring and autumn, chlorophytes during late spring, and cyanobacteria in summer months. Dinoflagellates had their greatest numbers in mid summer. Euglenoids and chrysophytes were present but in low numbers. The ratio of different groups showed that the lake is highly eutrophic. Copepods were abundant and examination of samples revealed that the cell volume of phytoplankton and length of filamentous algae affected zooplankton grazing on phytoplankton, consequently giving way to domination of Chlorophyta members larger than 60 mm in late spring and filamentous cyanobacteria species in summer months. Greatest community similarity index was found in November-December (37.5%) in 1997-1998, while the lowest values (6.25%) appeared in April-May in 1998-1999.