Intense bloom off coast of Devon and Cornwall, July 2000
At the start of July 2000 very high concentration of chlorophyll were seen from SeaWiFS off the south coast of Devon and Cornwall. This was distinct from a bloom in July 1999 that was highly reflecting and instead was strongly absorbing. Field measurements undertaken on the 25th July on the PML research vessel showed that the bloom was comprised of the 'red tide' dinoflagellate Gyrodinium aureolum . This species absorbs strongly in the blue and green regions of the optical spectrum and hence appears red on the false-colour composites comprising the SeaWiFS bands at 555, 510 and 443nm.
Also found within the bloom was a second plankton species, Noctiluca scintillans, which grazes on the G. aureolum. Noctiluca are visible to the naked eye (~1 mm in diameter), and in calm conditions float near to the surface. By virtue of the high numbers they appear as red patches, or streaks caused by the wind. Noctiluca are bioluminescent; that is, they glow in the dark, which is particularly noticeable if you sail through a patch at night.
You may view articles or hear reports about the bloom by clicking on the images below.