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Rains and floods overflow bringing fragile Murray Mouth back towards natural best

11 June 2022

Third generation professional fisherman Gary Hera-Singh at the Coorong, South Australia. Picture: Roy VanDerVegt
Third generation professional fisherman Gary Hera-Singh at the Coorong, South Australia. Picture: Roy VanDerVegt

Six decades on, he has watched in dismay as the Murray has been treated like an infinite resource, and the meddling of man with the interplay of fresh and salt water has imperilled this delicate estuarine system.

But now, thanks to sustained local rainfall and the overflow from the eastern states floods, there are signs that South Australia’s Lower Lakes and the Coorong are heading back towards their natural best.

The excitement is at its highest among the environmental scientists who monitor the lives of the plants, insects and invertebrates that underpin the local fish and bird population.

SA’s Environment and Water Department has several officers dedicated to the task around Goolwa, the southern Fleurieu port where the Murray Mouth closed over for the first time in 1981, prompting the desperate measure of dredging to create trenches to keep the river viable.

These officers also work with the local Ngarrindjeri people, for whom the Lower Lakes and Coorong has been their home and food source for tens of thousands of years, and who have the best read on how the system is faring since the modern interference began.

Adrienne Rumbelow has spent the past 10 years as the department’s program leader for the Coorong, Lower Lakes and Murray Mouth, and is heartened by the turnaround.

The lakes are managed via a system of barrages which control the release of fresh water into Lake Albert, Lake Alexandrina and the Coorong, the 100km long saline lake stretching south of the Murray from Meningie.

This financial year, an extra 6000 gigalitres of fresh water will be returned from the Murray to the lake system.

“In previous years when we get big floods or a solid rain it has been all over in a short and sharp way,” Ms Rumbelow told The Weekend Australian.

“Over the past 12 months we have had a lot of beautiful, steady rain, and as the water has made its way down we are really seeing the difference now with the ecological responses by birds, fish, aquatic vegetation and invertebrates.”

The biggest signs of success are the re-emergence in large numbers of the Coorong black bream, feasting on increased numbers of barnacles, mussels and tube worms, and the explosion in black swan numbers, fuelled by the growth of the sea grasses that make up their diet.

“There were at least 2500 more black swans here than last year,” Ms Rumbelow said.

Professional fisherman Gary Hera-Singh at work at the Coorong, South Australia. Picture: Roy VanDerVegt
Professional fisherman Gary Hera-Singh at work at the Coorong, South Australia. Picture: Roy VanDerVegt

For Mr Hera-Singh, these gains are bittersweet and serve only to remind him of the abundance of wildlife that had free rein in the area before the installation of the barrages and the pillaging of the Murray for water supply.

He says that whatever gains are being made in the Lower Lakes are less evident in the Coorong, which he says has been “kept on life support” via the purchase of water by the commonwealth.

The 66-year-old is a loyal son of the Coorong. Apart from four years working as a ski instructor in Austria in his 20s, the realness and rawness of the place has kept him in Meningie, where in addition to fishing he also owns the local bakery which is famous in SA for its excellent Cornish pasties.

“Both my grandfathers were commercial fishermen here, one of them for more than 50 years. I was destined to become a fisherman,” Mr Hera-Singh said.

“I know people are excited about the black swans being here but as a kid 60 years ago we used to measure swans by the acre and fish by the tonne. My grandfather used to talk about waterfowl blacking out the sky.”

Despite being passionately South Australian, Mr Hera-Singh refuses to point the finger solely at the eastern states for the degradation of the river and lakes.

“We are all playing our part in stuffing this up,” he said. “We take water in SA too, plenty of it. We take it for the Barossa Valley, we take it for our country towns.”

“The natural productivity is driven by flows from the Murray. If there is no fresh water there is no life, and the area now has about 10 per cent of its natural productivity. That means there is less resilience in the system at those times when we don’t have floods and rains. It will never be the way it was before the arrival of the white man.”

The Australian 

David Penberthy is a columnist with The Advertiser and Sunday Mail, and also co-hosts the FIVEaa Breakfast show. He's a former editor of the Daily Telegraph, Sunday Mail and