Spring bloom in a hypereutrophic lake, lake Kasumigaura, Japan—I Succession of phytoplankters with different accessory pigments

Abstract

Phytoplankters appearing during the spring bloom of 1980 in Lake Kasumigaura were classified into three groups characterized by different accessory pigments. Phytoplankters of the first group possess phycocyanin, those of the second group possess chlorophyll b, and those of the third group possess chlorophyll c. Only eucaryotic phytoplankters, belonging to the second or third group, were predominantly present during the bloom. Predominance of the second and third groups alternated during the bloom as individual phytoplankton pulses. The relationship between the population density of all phytoplankters and the abundance of phytoplankters possessing chlorophyll c could be expressed as a highly significant regression curve ( r = 0.7997) throughout the spring bloom in Tsuchiura Harbor: Y = 102.9 e −0.03138 X + 29.04, where X is the concentration of chlorophyll a in all phytoplankters in lake water, and Y is the percentage of chlorophyll a possessed by phytoplankters possessing also chlorophyll c.