Scurrying about the banks of Sydney’s Cooks River, an army of volunteers known as the ‘mudcrabs’ is working to bring one of the nation’s most toxic waterways back to life.
With gloves, wheelbarrows and pincer-like tools for picking up rubbish, the Cooks River Mudcrabs have been working for 20 years to restore bushland and clean up pollution around the river.
Those efforts are now gaining wider recognition, with local authorities hailing them as the “unsung heroes” in an ongoing fight to improve the river’s health following decades of abuse.
Reckoning with a toxic legacy
A car dumped in the Cooks River in the 1970s. (ABC News)
Winding its way through Sydney’s inner western suburbs, the 23-kilometre Cooks River was considered an industrial dump for much of the 20th century.
The river mouth was altered to accommodate Sydney Airport in the 1940s, and large sections upstream were converted into a concrete canal, depriving wildlife of a natural habitat.
By the 1970s, its waters were polluted with mercury, diesel and battery acid — and one infamous copper cyanide spill killed thousands of fish in the river.
Thousands of fish were killed in Cooks River. (ABC News)
Andrew Thomas from the Cooks River Alliance said the catchment was “ground zero for colonisation” and the city’s industrialisation.
“Basically it was just used as a dumping ground — cars, bikes, sewerage, you name it,”
Dr Thomas said.
“You’ve had tanneries, you’ve had clay pits, you’ve had a whole range of sugar mills, industrial activities that used it as a sewer.
“So, all their waste went straight into it and that legacy’s still with us today, locked into the sediments.”
Ms Gibbs says the river was polluted by large amounts of plastic. (ABC News: Gavin Coote)
It is because of this legacy that residents like Alison Gibbs avoided the river for many years.
“It was just filthy and incredibly polluted with plastic pollution,”
she said.
It was not until her children began riding their bicycles near the river that she began to see its potential and joined what would become the Cooks River Mudcrabs.
While there were only about a dozen volunteers in the early days, the Mudcrabs now have hundreds.
“We began to clean the banks, which meant 40 bags of rubbish,” Ms Gibbs said.
“The first clean up we didn’t even reach the mud. We were standing on bottles and rubbish, it was like an island of it. Layers and layers of shopping bags going down into the mud, but now I clean our site in two hours and it’s pristine.”
Piecing together the ecological ‘jigsaw’
Mr Benson says the mangroves are spreading along parts of the river. (ABC News: Gavin Coote)
Cleaning up rubbish is just one aspect of the Mudcrabs’ work — they have restored large tracts of bushland along the foreshore, providing a home to some species not seen there in decades.
A spin-off birdwatching group known as the Mudlarks does monthly surveys of the river, and retired botanist Doug Benson has also been monitoring the bush regeneration.
He said some species had acted as “missing jigsaw pieces” in the wider ecosystem.
“And of course, we have the mangroves, and they have spread remarkably along the river,”
he said.
“So the river now, instead of being just a series of grassy parks, there’s enough now in the mangrove component to support a whole lot of bird species. And our plantings, of course, are adding to that.
“It’s more than a corridor, it actually is now providing a major habitat in the local area.”
Dr Thomas says the catchment is “ground zero for colonisation” and the city’s industrialisation. (ABC News: Marcus Stimson)
Dr Thomas from the Cooks River Alliance, which represents local councils along the catchment, said the Mudcrabs were largely responsible for its transformation.
“I would suggest that they’ve done the lion’s share of much of the naturalisation work. They’re unsung heroes. They really have made a difference, and it’s something that we all benefit from,” he said.
Battle continues for river’s revival
The Cooks River catchment is home to about half a million — or about 10 per cent — of Sydney’s residents, and with more high-density housing being built in the area, its recreational value has only grown.
A landmark microplastics study by the NSW government last month found Cooks River remains the state’s most contaminated waterway, and locals said more funding is needed to deal with legacy problems.
Chief among those problems, both the Mudcrabs and Cooks River Alliance argue, are the aging sheet steel pilings that line sections of the river.
Ms Gibbs says the steel pilings are deterring wildlife. (ABC News: Gavin Coote)
Ms Gibbs said the structures, originally installed to help stabilise the river bank, continued to be a deterrent for plant and animal species.
“They’re breaking down, the banks are almost dangerous in parts and it’s just horrible. It makes the water run too fast, there’s no ecology able to develop along the river banks,”
she said.
But advocating for funding to have the steel pilings removed has been difficult, in part because of what Canterbury-Bankstown councillor Clare Raffan calls a “disconnect between levels of government”.
Cr Raffan, who chairs the Cooks River Alliance, said it had been “extremely difficult” to find out who was responsible for the maintenance of the pilings.
“It’s been left in the too-hard basket, because it’s going to cost a lot of money to remove and remediate that,” she said.
Cr Raffan says advocating for funding to remove the steel pilings has been “extremely difficult”. (ABC News: Marcus Stimson)
Investigations by the state government have found the sheet metal piling sits on land owned and managed by several different bodies — including Crown Lands, NSW Public Works, and local councils.
In a statement, a government spokesman said it has provided more than $1.5 million to develop a plan for the rehabilitation of the river.
“Cooks River is a much-loved place by the local community,” the statement said.
“We will continue working hand-in-hand with councils and community groups to prioritise the long-term naturalisation of the river, including looking at opportunities for further funding where necessary.”
The government said it acknowledged the “important work” of local organisations that had helped improve the health of the river “after generations of degradation”.