A mass fish death has occurred in the ornamental lake at Malmsbury Botanic Gardens, prompting an investigation by local authorities.
Macedon Ranges Shire Council parks staff became aware of the incident on March 20 after the Friends of Malmsbury Botanic Gardens and Environs reported about 20 dead carp floating on the lake.
Council chief executive Bernie O’Sullivan said a range of factors could have caused the event, but stressed there was no immediate risk to public safety.
“Incidents of this nature are concerning,” he said.
Council staff reported the matter to the council’s environmental health team and Environment Protection Authority Victoria, the lead agency for fish deaths and water health.
They also installed signage around the lake to warn the public and discourage contact with the water, and added a new pump and fountain to improve water quality and increase aeration.
Mr O’Sullivan said conditions worsened in the days after the initial report, with a strong odour and additional fish deaths, but had since improved.
“There have been minimal fish deaths reports since and the odour has dissipated,” he said.
“Water samples have been taken from the lake, and council is continuing to work closely with EPA Victoria on their investigations and potential future measures to support the lake’s ongoing health.”
Mr O’Sullivan also noted that carp were an invasive freshwater pest in Australia.
“Their habitation of the lake is a matter council is aware of and continues to actively manage, however this does not take away from concerns regarding the lake’s overall health or the recent unfortunate fish death,” he said.
