Algal Bloom in Lyttelton Harbour

Friday 21 September 2012, 2:08PM

By Environment Canterbury



Environment Canterbury’s Marine Oil Pollution Response Team has received reports of large oil spills over the past few days in Lyttelton Harbour.

Regional On Scene Commander for Environment Canterbury Jim Dilley would like to re-assure the public that this has been investigated and samples taken have discovered it’s algal bloom, not oil.

“The algal bloom looks just like an oil spill when viewed from a distance but once you get closer you can see that the coloured particles are under the surface of the water, rather on the top where oil would float,” he says.

Environment Canterbury’s Senior Water Quality Scientist Coastal Dr. Lesley Bolton-Ritchie says that the algal bloom, Mesodinium rubrum, is a very common ciliate.

“The discolouration of the water, which looks like oil, is due to the large amount of bloom that can change the seawater colour to brick red, brown or rusty red which it is known for.

“The reason for this outbreak of algal bloom could be a combination of sunny days and the water warming up mixed with recent rainfall causing the addition of nutrients into the water from rivers and streams.

“The bloom is non-toxic so the public has nothing to worry about,” says Dr. Bolton-Ritchie.

The algal bloom was discovered in the outer part of the harbour last week and it appears to have been further pushed up the harbour by the wind.

If you see an oil spill you can report this to the Pollution Hotline on 0800 76 55 88.