The Sooke Harbour and Basin has been looking decidedly “tropical” the last several weeks, with turquoise waters reminiscent of the Bahamas!
The creation of these blooms require the right combination of light/food/temperature for that particular species of algae. One theory is that recent rain events have moved nutrients into our waters, which have warmed up during the last few sunny days.
Algae blooms are natural and are not necessarily an indicator of water quality concerns.
The water has been tested and the results show no risk to humans. The organism most likely responsible for the brightly colored water are ‘coccolithophores’ as they are highly concentrated in the samples taken by CRD staff, according to a release.
Members of this group are noted to bloom in areas where there is a combination of a period of low wind speeds, stratified water with a shallow top layer that has been exposed to intense sunlight. They are reported to bloom in waters that are both low and high in nutrients such as phosphorus and nitrogen. The characteristic bright green colour imparted to the water during a bloom is not caused by the colour of the organisms themselves but by excess scattering of light which increases reflectance.
Blooms are sometimes so vast and colourful that in some cases they are visible from outer space.