GM of Surf Life Saving NZ Northern region Zac Franich gives us his top tips and tricks for staying safe this summer in and around the water. Video / Carson Bluck
New signs warning lake users of toxic algal blooms have been put up around 40 lakeside locations in the Rotorua district as rising outdoor temperatures increase the likelihood of cyanobacteria breakouts.
More common in the warmer months, algal blooms can affect lakes and rivers and are potentially toxic for humans and pets.
In a statement, Rotorua Lakes Council, in partnership with Te Arawa Lakes Trust, Te Whatu Ora Health New Zealand and Bay of Plenty Regional Council, announced the new signs to proactively warn lake users about the risk of toxic algal blooms.
“The blooms can happen suddenly, so it’s important to always check the water before entering or letting dogs play,” the statement said.
The new signs provide information about what algal blooms look like, and the symptoms to watch out for if humans or pets come into contact with toxic algae.
While toxic algae may not be present, the signs would remain in place as permanent education at more than 40 lakeside locations around the district.
Should toxic algae be identified through testing, an official warning would be issued by Toi Te Ora Public Health and would be shared online by Toi Te Ora and Rotorua Lakes Council.
Toi Te Ora had health warnings in place due to algal blooms for Lake Ōkaro, Lake Maraetai and Lake Ohakuri.
New signs proactively warn lake users about the risk of toxic algal blooms.
Check the water for algal blooms before using lakes and rivers this summer
During the warmer months, there can be potentially toxic blue-green algae present in lakes and rivers.
In a statement, Toi Te Ora Public Health medical officer Dr Gregory Evans said there was reduced capacity to monitor for algal blooms over the Christmas and New Year period.
“So it’s important to know the signs of algal bloom to reduce your chances of becoming unwell.
“Algal blooms can develop rapidly and unpredictably and can sometimes produce toxins that are harmful to people and animals.”
Evans said contact with the water should be avoided if it looked discoloured, had an unusual smell, had green or brown particles suspended in it, or if scum or leathery mats of algae were on the surface or the bottom of the waterway.
“These blooms have the capacity to release toxins into the water which can cause skin rashes, stomach upsets and visual problems for anyone who has contact with the water. They can also affect the nervous system causing numbness, difficulty with breathing, and asthma attacks.”
Lakes were typically dominated by free-floating algal blooms, while rivers were more prone to algal blooms that grew in mats attached to rocks at the bottom. They could also build up at the shoreline.
“Algal mats and scum can build up along the edges of lakes or rivers. It’s important parents ensure children avoid contact with these as they may be toxic.”
Evans said anyone who thought they had been in contact with algal blooms needed to shower and change clothes as soon as possible even if no symptoms were present.
“You should seek medical advice from your GP if you become unwell after having contact with recreational water,” Evans said.
“Dogs are also at risk of serious illness if they consume or have contact with toxic algae or algal mats that accumulate in and around rivers. They should be kept away from the water if it looks like there may be a bloom.”
