Kia tūpato, take care – Wairarapa Moana to get toxic algae checks

Toxic algae will be monitored in Wairarapa Moana this summer to ensure the water is safe for recreational activities. Greater Wellington’s summer monitoring programme tests the quality of waterways around the region and issues warnings when toxic algae levels are high.

A red level warning for Wairarapa Moana was issued in March this year says Greater Wellington’s senior advisor for integration and insights, Penny Fairbrother.

“Toxic algae in lakes looks very different to what we see in rivers. Rather than growing as velvety black mats on rocks in the riverbed, toxic algae in lakes is free floating and can make the water look bright green like pea soup,” says Fairbrother.

“If water with toxic algae in it is swallowed, it can make both people and animals very sick and potentially cause death. Inhaling water aerosols (for example through splashing) or direct contact with skin can also cause issues such as respiratory issues and skin irritations.”

Wairarapa Moana will be monitored weekly by student interns working with Greater Wellington, along with the usual river sites around the region.

The data will be available on the ‘Can I swim here?’ page on the Land Air Water Aotearoa (LAWA) website and ‘Kia tūpoto – Warning’ signs will be put out at the lake at several locations in case of a major bloom/high levels that make the water unsafe for human or animal contact.

Alerts will also be issued on Greater Wellington’s social media and website.

Lake algae

• Toxic algae is free floating in the water and can cause a murky or bright green ‘pea soup’ appearance
• Bright green or brown scum may accumulate at the lake edge, 
• Do not swim or let your dog into the water.
• Do not collect or eat shellfish from the lake.
• Fish caught from the lake are safe to eat, as long as they are cleaned well and gutted. (Dispose of the guts safely so that animals cannot scavenge them).

River algae

• Toxic algae grow on rocks in the riverbed and form leathery dark green or black mats.
• Mats can wash up on the riverbanks, where they dry out and turn light brown and crusty.   
• Toxic algae mats have a musty smell that’s particularly appealing to dogs.
• If an alert has been issued, dogs should be kept on a lead.  
• Don’t let dogs scavenge at the riverbanks or let them roll in algal mats.
• It only takes a mat the size of a 50c coin to kill a dog if eaten.

More information

• Toxic algae presents the greatest risk to children, pregnant people and the elderly.
• Symptoms can include a skin rash/irritation, nausea, stomach upset, tingling/numbness around the mouth and/or fingertips and breathing difficulties.
• Call Healthline on 0800 611 116 or see a doctor if you are concerned about exposure to algae and any symptoms.
• If you think your dog has swallowed toxic algae, or it is showing signs such as lethargy, excessive panting/drooling, tremors or seizures, take it to the nearest vet immediately.  

Always check it’s safe to swim before you visit a river, beach or lake at LAWA.

For more information on toxic algae, visit our toxic algae page.