A coccolithophorid bloom in Jervis Bay, Australia

A massive algal bloom of the coccolithophorid Gephyrocapsa oceanica Kamptner (Prymnesiophyceae) developed in Jervis Bay, a coastal embayment at 34ºs on the New South Wales coast, in mid December 1992. The bloom coloured the entire bay a dramatic milky blue-green, which was clearly visible from aircraft and detectable in the visible band by the US satellite NOAA-11. The bloom, which reached cell densities of 1.8 x 107 cells L-1, persisted for a month. Such high densities of coccolithophorids have not been recorded before in Australian waters. Furthermore, it is the first record, world-wide, of a large-scale mono-specific bloom of G. oceanica. The bloom is suggested to have been driven by an intrusion of continental-slope water that continuously entered into the bottom of the bay.