PHOTOPERIODIC CONTROL OF DIATOM SPORE GROWTH - A THEORY TO EXPLAIN THE ONSET OF PHYTOPLANKTON BLOOMS

Photoperiod influences the timing of several growth processes in higher plants and macroalgae. Results from our experiments indicate photoperiodic control of germination and/or growth of diatom resting spores. We suggest that the onset of phytoplankton blooms in northerly areas, and possibly also further south, may be photoperiod dependent and linked to entrainment of phytoplankton resting spores from bottom sediments.