A “vigil” has been held at Parliament House in South Australia for 10 hectares of mangroves that died due to a salt mining mishap north of Adelaide.

Key points:

  • About 150 people attended at vigil for mangroves that died at St Kilda
  • Community leaders and the Opposition have questioned the Government’s handling of the situation
  • There are warnings that many more mangroves remain at risk, with hypersaline water still leaking into the area

The aquatic trees surrounding the popular St Kilda Mangrove Walk, along with 35ha of salt marsh, are believed to have been killed by leaking salt brine from nearby gypsum ponds.

About 190ha of mangroves in the area are thought to remain at risk.

Last year the ponds were refilled for the first time since 2014, but the gypsum lining had dried out and cracked, enabling hypersaline brine and acid to leak into the adjacent mangrove forest.

Environmentalist and consultant Peri Coleman, who was among those working to raise the alarm since September, said she was not surprised to see a turnout of about 150 people at today’s event.

“Forty years’ worth of schoolchildren have come through that mangrove trail and Adelaideans love it intensely,” she said.

Dead trees surround the popular St Kilda Mangrove Trail in Adelaide’s north.(Supplied: Alex Mausolf)

Ms Coleman said despite the miner, Buckland Dry Creek, being told by the Department for Energy and Mining (DEM) in November to cease operations – and ordered on December 24 to pump water out of the ponds – the acidic water “was still there and it was still leaking out”.

“The impact goes well and truly beyond that area and into the area where the very old trees are,” she said.

Today’s vigil included speeches by several community group leaders, Opposition Leader Peter Malinauskas, Labor MP Susan Close and Greens MLC Mark Parnell.

Environmental consultant Peri Coleman has been studying the cause of mangrove deaths.(ABC Radio Adelaide: Malcolm Sutton)

Questions of direction

Mr Parnell took aim at the Government for making DEM the lead agency in the investigation and incident response, which the Government said was being undertaken in collaboration with the SA Environment Protection Authority and the Department for Environment and Water (DEW).

“One of the problems is the mining department doesn’t take environmental protection as seriously as other departments,” he said.

“Most of their clients are, by definition, harming the environment all of the time, clearing great swathes of vegetation and digging big holes in the ground.

Mr Parnell also claimed the DEM had not pushed Buckland Dry Creek to mitigate the issue within a reasonable timeframe.

“For me, a reasonable response would have been, ‘You get down there straight away and if you need extra pumps, put more infrastructure in, because it is a matter of upmost environmental importance that you get this water out of the location right now,'” he said.

“But the idea they can give them notice on Christmas Eve, and tell them to take their time if they need a few days off to have a holiday with the kids … it’s a problem.”

Greens MLC Mark Parnell questioned the DEM’s decisions.(ABC Radio Adelaide: Malcolm Sutton)

‘Technical’ responsibility

DEW Minister David Speirs said the DEM had responsibility for the regulation of the incident in a “purely technical sense”, but it was an “environmental problem” that he would be working on at the “forefront with the Energy Minister and the Premier”.

“I think we need to get on top of the problem and work through the solution in the first instance,” he said.

“There will be time to work out who’s at fault down the track.

“There’s been a lot of flushing happening there out of the salt pans since January 11.

Mr Speirs said he did not want to see any mangroves die, but the dead mangroves represented about two per cent of the area.

“Peri has rightly said there are other areas under stress, but I do think – and the scientist tell me – that we can get in front of that with the flushing that’s occurring,” he said.

“We have to be very careful we don’t just move water from one area to another as it’s hypersaline water and could cause another problem.”

Mark Pierson and Peri Coleman’s daughter, Faith, were among those who spoke at the vigil.(ABC Radio Adelaide: Malcolm Sutton)

But Friends of Gulf of Saint Vincent secretary Mark Pierson said the Government had been caught with its “head in the sand and feet stuck in the mud”.

“I think there’s a lot of people pointing the finger at each other in Government, but no one’s actually stepping up to take responsibility,” he said.