Dr Alistair Humphrey, Canterbury Medical Officer of Health

Algal bloom warning

by Laurie Willetts

The Community and Public Health division of Canterbury District Health Board has issued a health warning after potentially toxic blue-green algae (planktonic cyanobacteria) was found in Lake Forsyth/Te Roto o Wairewa.

People and animals, particularly dogs, should avoid the water until the health warning has been lifted.

Canterbury Medical Officer of Health, Dr Alistair Humphrey, says the bloom can produce toxins harmful to humans and animals.

“Exposure may cause skin rashes, nausea, stomach cramps, tingling and numbness around the mouth and fingertips — if you experience any of these symptoms visit your doctor immediately. No one should drink the water from the lake at any time. Boiling the water does not remove the toxin.

“Animals that show signs of illness after coming into contact with algal mats should be taken to a vet immediately.

“Fish and shellfish can concentrate toxins, and their consumption should be avoided. If fish are eaten, remove the gut and liver and wash in clean water.”

Environment Canterbury monitors the lake, and the public will be advised of any changes in water quality that are of public health significance.

For further information visit ecan.govt.nz/your-region/your-environment/water/swimming-water-quality/.