Lincoln – A health warning has been issued after potentially toxic blue-green algae, or planktonic cyanobacteria, was found in Te Roto o Wairewa – Lake Forsyth near Banks Peninsula, Te Whatu Ora Health NZ says.
People should avoid the lake and animals, particularly dogs, should not be allowed near the water until the health warning has been lifted.
Dr Cheryl Brunton, Waitaha Canterbury’s medical officer of health, says the algal bloom can produce toxins harmful to humans and animals.
People should avoid contact with the water until further notice. Exposure may cause skin rashes, nausea, stomach cramps, tingling and numbness around the mouth and fingertips.
If people experience any of these symptoms they should visit their doctor immediately and tell the doctor if they have had contact with the lake water.
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 or scums 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 weekly and the public will be advised of any changes in water quality that are of public health significance.
The cyanobacteria occur naturally but can increase rapidly during warmer months. Algal blooms are caused by a combination of nutrients in the water such as nitrogen and phosphorus and favourable weather conditions like increased temperature and calm days.
If the water is cloudy, discoloured, or has small globules suspended in it, avoid all contact.
Not all cyanobacterial blooms are visible to the naked eye and toxins can persist after the blooms disappear.
Cyanobacterial concentrations can change quickly with changing environmental conditions such as wind. If a health warning is in place avoid contact with the water.
For further details visit: https://www.lawa.org.nz/explore-data/canterbury-region/
Or https://www.cph.co.nz/your-health/recreational-water/
For information about mahinga kai:
