Toxic algae alert continues for Wellington region
The summer holidays are fast approaching for many of us – and although recent rain has seen a reduction in the extent of
waterways affected by toxic algae – warnings remain unchanged. Expected warm weather and low river flows are likely to
cause current conditions to persist into the new year.
The public is asked to be on the lookout for thick green-black slimy algae in the water, and also stranded dead brown
algae alongside rivers and streams. It is thought the dead or dry algae may pose an even greater risk than that in the
water.
Howard Markland, Pollution Control Co-ordinator for Greater Wellington says people should be aware that any freshwaters
in the Wellington region have the potential to be affected. To date toxic algae has been detected in the Hutt and
Mangaroa Rivers, Wainuiomata River and tributaries of the Otaki and Waikanae Rivers. He says slow flowing rivers and
streams where the water is shallow and warm are most likely to be affected. Unfortunately these are also the most
attractive to swimmers and dogs.
Consuming or contact with algal toxins may be harmful to people. Regional Public Health Medical Officer of Health, Dr
Margot McLean, advises everyone to avoid contact with algae in rivers or on their banks. It is important Margot says,
“that people don’t swim with their heads under the water. In particular, parents or caregivers should supervise young
children playing close to the river to ensure they do not touch or eat any algal material, or drink the water. Dogs in
particular are vulnerable to toxins and should be kept on a leash near rivers and streams. They should be restrained
from eating algal mats in, or near water.”
Possible algal toxin symptoms include an irritation or allergic type rash. Ingestion can lead to gastro or respiratory
symptoms, and potentially affects the liver or nervous system. If you experience any of these symptoms get out of the
water and wash yourself with clean water. Contact your doctor if you’re concerned about symptoms. If your dog is
affected get to your vet immediately. The vet will notify the council to arrange investigation.
Local councils are continuing to monitor the extent of algae in our rivers, but are unable to monitor the entire length
of all rivers in the region. People must use commonsense, look out for, and avoid algae mats. If anyone sees unusual
algal growth they’re asked to contact their local council. It is unusual to find toxic algae in rivers, and there is
little information on its risks and effective controls. Local councils are relying on public support to provide
additional information, and exercising caution when near affected waters.
ENDS