Public asked to be aware of algae in rivers

	Mat forming blue green algae in Hutt river

Recent dry weather over the region has Greater Wellington and health agencies warning river users to be wary of exposed algal mats on riverbanks and ‘floating' on the surface in shallow areas.

Current monitoring by staff from Greater Wellington and Local Councils has identified growth of potentially toxic blue-green algae in some areas of the Hutt and Waikanae rivers. Growth of algal mats is common in rivers throughout the Wellington region during periods of low river flow and warm temperatures.

However, continuing warm and dry weather combined with low river flows may mean that algal mats become exposed or easily accessible to dogs, stock and recreational users.

Dogs are particularly susceptible to the toxins because they love to scavenge near water. Contact with blue-green algae toxins may also cause vomiting, diarrhoea and skin irritations in humans.

Rivers users - particularly those with dogs, those swimming, or drawing water from the river for stock/human consumption - should be on the look out for exposed or easily accessible algal mats and avoid any contact with them or water in the area.

Dog owners are advised not to let their dogs scavenge on the river's edge. Blue-green algae mats are usually dark green/brown in colour or light brown/white when dry and often have a strong musty odour. Blue-green algae mats should not be confused with the harmless bright green algae which grow in fluffy patches or long strands.

A staged response protocol developed between agencies after similar conditions in summer 2005 allows for Territorial Local Authorities to respond should local river conditions require signage.

If any person or animal in your care exhibits signs of illness after being near the river/s, contact your doctor or vet immediately.

If you see any exposed or easily accessible algal mats that wouldn't normally be in the area, please contact the environmental health officer at your local Council.

More information about toxic algae can be obtained from Greater Wellington at www.gw.govt.nz/on-the-beaches, or from the environmental health officer at your local council.