Public health risk: algae confirmed
• A close-up of the algae at Blackmans Lagoon.
• The new signage which has been installed at Blackmans Lagoon. Photo supplied.
November 27, 2019
Water quality samples from Blackmans Lagoon in the Waterhouse Conservation Area have returned positive results for blue-green algae.
The Tasmania Parks and Wildlife Service Field Centre staff first investigated the issue two weeks ago, following public concerns about the health of Blackmans Lagoon.
Dorset Council is now responsible for managing the issue and providing advice as it is a matter of public health and safety.
Precautionary signage located at public access points and recreational areas of Blackmans Lagoon was updated on Friday morning to notify the fishing community, residents and other users about the outbreak.
Dorset Council’s Environmental Health officer (EHO) Robert Masterman said the Department of State Health, Inland Fisheries Service and Parks and Wildlife have also been notified of the sampling results.
“The dominant species of blue-green algae identified are potentially toxic and may cause harm to people and animals,” he said.
“Contact with the affected water may cause skin and eye irritation as well as hayfever-like symptoms, and people undertaking activities where they may be coming into direct contact with the water (swimming, showering or washing) do so at their own risk.
“In addition, ingesting the affected water may cause gastroenteritis symptoms such as diarrhoea, fever, headache and vomiting.”
He said Council will continue to monitor the water quality and will update or remove signage should the blue-green algae levels dissipate.
Waterhouse farmer Roger Bignell has been drawing water out of Blackmans Lagoon for stock for the past 40 years.
He said water rights are attached to their title which was put in place via soldier settlement back in 1956.
Another Waterhouse resident Jennifer Reid said her main source of water comes from Blackmans Lagoon and they have been using that for the past six years.
She said while they had not been informed of the positive result, there were noticeable changes to the water quality.
“The water is extremely smelly and unfortunately we have no choice but to continue using it as our drinking water tank is too small to sustain or keep the house running,” she said.
“We have to wash clothes and bath in that water – it’s our main water supply.”
She said when the Scottsdale Irrigation Scheme is completed they will draw water from that.
Mr Masterman concluded: “As the presence of blue-green algae has been confirmed, coming into contact with the affected water may cause illness in humans and animals including live-stock.”
At the time of printing, residents drawing from the supply had not been directly informed by Dorset Council or Parks and Wildlife.
Parks and Wildlife were asked how they plan to address the low water levels in Blackmans Lagoon in the future, but they did not respond.
Possibilities that have been floated include flushing the Lagoon with water from the Scottsdale Irrigation Scheme.