On and off for algal blooms

Results from busy blue-green algae-monitoring programs across the region continue to frustrate recreational water enthusiasts.

Despite conditions prompting authorities to lift algae warnings at some lakes and impoundments, they are generating new or persistent warnings at others.

Gwmwater has confirmed an outbreak of toxic blue-green algae is over for Lake Toolondo south of Horsham.

But Vic Emergency warnings are in place at Lake Charlegrark near Goroke and further west at Mullinger Swap Wildlife Reserve on the South Australian border and Lake Bolac, south of Ararat.

Gwmwater issued a statement late last week detailing how blue-green algae levels at Toolondo no longer posed a health risk to recreational activities such as boating, fishing and swimming.

Authorities have detected high levels at Lake Charlegrark since mid-january and expect the bloom to remain until significant rain flushes the lake or cool weather slows algal growth.

Warning signs at the lake outline how people should avoid direct contact with water from the lake or using the water for cooking, drinking, washing of showering. Boiling water does not make it safe to use.

The same message applies to Lake Bolac and Mullinger Swamp.

Blue-green algae, which is actually a microscopic bacteria called cyanobacteria and responsible for oxidising the planet millions of years ago, occurs naturally in many Australian waters.

Changes to environmental circumstances can generate population explosions or ‘blooms’ and a subsequent range of problems.

Primary health issues involving humans and other animals are related to cyanobacteria releasing potentially harmful cyanotoxin into water, often when the organism dies.