The local Medical Officer of Health is reminding the public to exercise caution when looking to cool off in Lake Taupō.
Last week, Waikato Regional Council confirmed the presence of potentially toxic algal species, including Phormidium, had been found at five sites around Lake Taupō. As testing continues, today Waikato Regional Council staff confirmed a toxin-producing species of algae bloom, similar to that found at the previous five sites had also been identified at Halletts Bay. The Medical Officer of Health, Dr Jim Miller, has now extended the health warning to include Halletts Bay.
“People are advised not to paddle, wade, swim, or participate in any recreational activity that might involve any direct contact with the algae or swallowing of the affected lake water at Five Mile Bay, Acacia Bay, the main lake front in Taupō, Whakaipo Bay, Kinloch Beach, and Halletts Bay,” says Dr Miller.
Toxic algal species often multiply to high levels during periods of warm, sunny weather. In lakes they can form extensive green to black-coloured mats that settle on rocks and the lake floor. Significant clumps sometimes break off and float free, collecting on the water's edge. “The algae that form algal mats can release toxins that are potentially harmful to people and animals,” says Jim.
As toxic algae can occur in other areas of the lake at any time, Dr Miller advises people to make their own visual assessment of areas of the lakes which are not included in the health warning. “The algal mats can come free and accumulate on the shoreline or float on the surface,” says Dr Miller. “While there are six areas currently known to be affected, due to the weather conditions the blooms could disperse or occur in other areas of the lake, so the community should be vigilant and check for signs of algal mats before entering the water in other areas,” he adds.
“Lake Taupō is a big body of water, and the sampling points are limited. Algal blooms can occur quite quickly, and the current warm conditions are perfect for toxic algae growth, so it is always safest to check the water before you get in. Look before you leap; if the water looks discoloured, smells unusual, or if there is scum on the surface, swim or play somewhere else.”
Contact with algal mats can cause skin rashes, stomach upsets and respiratory symptoms such as triggering of asthmatic attacks. If material from algal mats is swallowed it can cause neurological symptoms such as numbness and weakness, visual symptoms and, in severe cases, affect the ability to breathe.
Waikato Regional Council staff will be carrying out further sampling at the sites tomorrow, with the testing to be carried out by NIWA. The results are expected later this week.
Taupō District Council and Tūwharetoa Māori Trust Board are working in partnership to get drone footage of the affected areas today and tomorrow. This is to give the team monitoring the situation, including the Medical Officer of Health, the most up-to-date information.
Members of the public who notice algal blooms in other areas can report them to the Waikato Regional Council on 0800 800 401.
For health advice, people should call the Healthline on 0800 611 116. For advice on drinking water and beach access call the Taupō District Council on 0800 ASK TDC (0800 275 832).
Signage has been erected by Taupō District Council at six affected beaches.