Aidan Curtis
PICCANINNIE Ponds Conservation Park is still closed to divers and snorkelers as National Parks and Wildlife South Australia (NPW) continues to monitor the after-effects of a massive algae outbreak.
The pond was closed in late February after a significant outbreak of filamentous algae covered most of the water’s surface, with NPW staff and contractors working for weeks to remove it.
Over 10 tonnes of algae was removed, but water testing undertaken at the pond on Wednesday, April 27 showed the pond was not yet ready to be reopened to divers and snorkelers.
NPW regional manager for the Limestone Coast Nick McIntyre, along with conservation ecologist Claire Harding and district ranger Ross Anderson, took a look below the surface and found there was still plenty of algae causing problems.
Mr McIntyre said getting in the water was all a part of their routine monitoring of the site.
“We just wanted to check the water clarity and to look for the window of opportunity for when we might open the site,” he said.
“Compared to what you would have seen three, four weeks ago at the height of the algal outbreak, it looks really good from the top.
“However, as we immersed ourselves in the water, we discovered suspended algae in the water.”
He said there was also a lot of algae collecting on and around plant life in the water, which could potentially cause a lot of damage to the ecosystem.
“It’s reducing that sunlight effect and damaging the plants,” he said.
“Our concern is that will either drop down to the base of the pond or it might aggregate and be sitting there ready to grow when the weather conditions and the seasonality ripen in late 2023, early 2024.”
Ms Harding said they would continue taking samples to better inform their choices in mitigating the effects of future algae outbreaks.
“Part of those investigations we’ve got going forward is looking at nutrients in the water and where those nutrients might be coming from,” she said.
“We’re continuing to monitor the site, and then looking at, in winter time, perhaps operating the weir to flush that algae out of the system.
“We fully expect that we will be having to remove algae again in summer and maybe for quite some time.”
NPW can not yet say when Piccaninnie Ponds will be reopened to divers and snorkelers.
