ABSTRACT: A review of natural bloom and mesocosm data for Emiliania huxleyi suggests a connection between bloom formation, shallow mixed layers and high light intensities. But how does E. huxleyi differ from other algae in its response to light, and what is the cause of the competitive advantage at high light intensities? In this article, P-I curves for calcified, naked and de-calcified cultures of E. huxleyi are presented. The experimental results show that a lack of photoinhibition in E. huxleyi up to at least 1000 uEin m^-2 s^-1 may contribute to the dominance of this species at high light intensities, and that this lack of photoinhibition is not due to the presence of reflective coccoliths around the cell.

KEY WORDS: Emiliania huxleyi . Photosynthesis . P-I curves . Photoinhibition . Stratification . Phytoplankton ecology

Published in MEPS Vol. 136 (1996) on June 6
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 1996