JOURNAL OF PLANKTON RESEARCH | VOLUME 6 | NUMBER 3 | PAGES 385-397 | 1984
© Oxford University Press
research-article |
Physiological responses of phytoplankton to turbulent and stable environments in an upwelling region
Sea Fisheries Research Institute Cape Town, South Africa
Received on January 1, 1983; accepted on January 1, 1984 The assimilation of 14C into photosynthetic products was monitored in two phytoplankton blooms growing in turbulent environments during February and March, 1981. The March community appeared to store a large proportion of carbon in sugars, polysaccharides and lipids in the upper euphoric zone, but as the cells were mixed to deeper depths the flow of carbon was directed into organic acids, amino acids and protein near the bottom of the euphotic zone. In February, the winds that induced initial deep mixing moderated during the second half of the study allowing the water mass to stabilize. Total assimilation by the community was greater under mixing conditions than in the stable water, implying faster growth in a turbulent environment. When the community was growing in the stable water a greater percentage of carbon was incorporated into protein, however. Since algal growth is linked to protein synthesis it is suggested that growth in the stable environment was faster than in the turbulent environment.