During the warmer seasons, freshwater areas can break out in toxic algae, viruses and bacteria.

Te Whatu Ora, medical officer of health, Dr Phil Shoemack shares some advice for those wanting to use freshwater areas such as lakes and rivers.

Dr Shoemack says that there is currently an issue in Okawa Bay at the western end of Lake Rotoiti in Rotorua.

A health warning was issued on January 5 by Toi Te Ora for Lake Rotoiti warning people to stay away.

The lake is being monitored and test results have shown that there is a bloom of potentially toxic blue-green algae.

“Given the weather pattern at the moment and the forecast for the next few days, it wouldn’t be surprising if we get more blooms,” says Dr Shoemack.

“Be observant. Have a look at the water, if it’s discoloured, wither brownie colour or a bright green.

“Sometimes with these blooms, it can look like pea green soup.

“The water can be discoloured by the bloom and sometimes you might see a globby mass sitting on the bottom, particularly in slower-flowing streams.

“They can be quite brown, gooey, sticky and messy.

“If swallowed, even inadvertently, it can lead to diarrhoea as well.

“Where there’s a bloom present you should avoid all contact with the water.

“You might get away with fishing so long as the fish looks healthy when you catch them, but you don’t want to get into the water or get any on yourself.

“The blue-green algae or cyanobacteria are capable of producing toxins which can be really harmful, particularly to animals.

“Dogs are amazingly susceptible to it but people as well.

“If the toxins are present it can cause rashes, it can lead to tingling around the mouth and tips of your fingers, it can also spark asthma attacks in people who get asthma.”

Dr Shoemack warns that this is serious and people need to be aware and be cautious.

He says that this is generally only a problem for freshwater.

“Generally speaking we don’t see this in harbours or beaches.

 “You certainly wouldn’t want to go [water] skiing and you wouldn’t want to go swimming.

“Even if there is no warning in place, these things can crop up within hours.

“We only do monitoring once a week and it takes 48 hours at least for the lab to do the necessary analysis.

“If the water looks like there’s an algae bloom pleasant, if it’s discoloured, if it smells, if there’s dead fish along the shoreline, go somewhere else.

“Over the summer months, we work with the local councils and the regional council and complete this regular monitoring and we do our best to keep the public informed.

“If the bloom goes away and we’re confident that it’s no longer a problem, we’ll lift the warning.”