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The death of hundreds of thousands of fish in the Murray-Darling Basin was unprecedented, but it was not without warning. By Karen Middleton.

Fish kill: What led to the Murray disaster

From the witness box at South Australia’s Murray-Darling Basin Royal Commission last year, Alan Whyte predicted the coming summer would have a terrible impact on the Lower Darling, just below the Menindee Lakes.

“Once the weather warms up … it’s going to stink like a septic tank,” the Sunraysia citrus grower said of the river system, in evidence to the commission in Adelaide on July 17, 2018.

“We have already had red alert warnings for blue-green algae outbreaks and as soon as we get into the warm weather, that is what’s going to happen. I refer to it as ‘muck’, and that’s the simplest description I can come up with. I don’t think you would let your dog swim in it.”

Whyte’s farm, Jamesville, is 65 kilometres north of the town of Wentworth on the stretch of the Darling River just below where only six months later hundreds of thousands of fish – locals say possibly a million – died suddenly on January 7.

This week, Whyte told The Saturday Paper he based his prediction on the volume of water left in Lake Menindee.

“We knew we were headed for trouble,” he says of his fellow farmers. “We were getting ready for trouble that we thought would be coming in December.”

That trouble came with sluggish flows and high temperatures. Then an algal bloom and a fish kill in December in the Lower Darling and another, bigger one in the same area in January.

A preliminary New South Wales government investigation identified several immediate causes of massive loss of fish in the Murray, publishing its findings on Thursday.

According to investigators, low water flows, including less-than-anticipated amounts of water being released from a lake upstream, encouraged the growth of blue-green algae.

Then a cool snap between January 4 and 5, combined with high winds, caused usually separate layers of cold and warm water to mix.

The cold water carried less oxygen than the warm, lowering oxygen levels overall. The cold water also killed parts of the algal bloom, further robbing the water of oxygen. The fish that died were mostly golden and silver perch, Murray cod – some decades old and under threat – and bony herring.

NSW Water Minister Niall Blair told The Saturday Paper: “You could prevent fish kills – if you had more water.”

But he and Alan Whyte believe a number of broader factors played a role, including how water was released from Menindee over the preceding two years to boost the environment further downstream – leaving too little for the dry period.

Whyte says temporary weirs known as block banks, built to help conserve water, were also constructed too late.

“We wanted the banks in place, so we could shift the water into deeper columns in cooler weather,” he says. “Shifting low flows of shallow water in warmer weather will end in tears.”

By tears, he means evaporation, stagnation, toxic algae and dead fish.

Niall Blair says the block banks required regulatory approval and were installed as quickly as possible.

But the farmer’s warning, six months ago, couldn’t have surprised officials trying to manage the distribution of water up and down the massive river system.

Their own maps of likely algal hotspots were dotted with red markers identifying sites at high risk.

The question now being asked is whether more could have been done to prevent what happened in the Darling River and whether the damage done by decades of jurisdictional squabbling and overuse of a mighty river system can ever be repaired.

In the wake of the January incident, the NSW government installed aerators in the river to provide oxygen refuges for fish, each one only about the size of a tennis court.

The NSW minister defends not having installed them sooner. “We certainly didn’t have any indication that we would see something as big as the one that we saw in January,” says Blair.

At a media briefing eight days after the January kill, Phillip Glyde and other officials from the Murray-Darling Basin Authority (MDBA), the Commonwealth Environmental Water Holder and the federal Department of Agriculture and Water Resources denied it was unprecedented, citing 40 such events across NSW every year.

But they then conceded that in terms of the number of fish affected – and in repeat events – “unprecedented” was a fair description.

While federal ministers attributed the deaths primarily to the drought, Glyde identified the major underlying problem.

“This is a river that has been overused over the last 100 years,” he said.

Greens senator Sarah Hanson-Young insists it’s still overused, accusing the cotton industry of running the river dry – something the industry strenuously denies.

Alan Whyte says another factor was the timing of releasing water out of the Menindee Lakes.

The release was designed to aid the Murray River further downstream – without which, the MDBA insists, things could have been worse.

Whyte argues the authority ended up helping areas that are home to a clutch of marginal SA seats – but hurting the Lower Darling.

“They’re doing it at times when they wouldn’t normally have done it and that’s one of the reasons – I stress only one of the reasons – there’s a fish kill.”

Under the Murray-Darling Basin Agreement, Lake Menindee is under the control of federal authorities – who can take water allocated to the environment and release it – until its total water storage falls to 480 gigalitres.

When it drops to that level, NSW takes over, prioritising the water to supply Broken Hill and communities and industries nearby instead. It remains under state control until the level rises once again to 640 gigalitres.

Niall Blair also attributes blame to the timing of water releases. “How much has been taken by the MDBA?” he asks. “How much has been sent to South Australia and how much is being released for the environment?”

He says after a 2016 deluge, the agencies released too much water too soon.

“They are operating under the rules, but those rules were also drawn up on assumptions that water would come back into the system,” he says.

But because evaporation claims hundreds more gigalitres, Phillip Glyde insists that “if you don’t use it, you lose it”.

Blair criticises the federal agencies – the MDBA and the Commonwealth Environmental Water Holder – and his own government’s Office of Environment and Heritage over their handling of the releases.

“I don’t want any more water coming out of NSW to flow through to SA, whether it’s [from] the Murrumbidgee, the Lower Darling or the Murray, unless it has a socio-economic benefit to the source area,” he says.

Asked if the outcome would have been better if the water had been held back, Glyde said: “We really can’t tell. We would say we did as good a job as we can, under those uncertain circumstances.”

Alan Whyte says the MDBA was operating legally.

“All Phil Glyde and his mob have done is follow the rules,” Whyte says. “Trouble is, they’re not thinking about the consequences in the real world. And the consequences two weeks ago were a million dead fish.”

Investigators estimate the number was closer to 300,000.

Basin plan critics fear changes that passed through federal parliament in May last year could increase the risk of repeats.

Resulting from a northern basin review, the changes the MDBA recommended will reduce the amount of water recovered from users in favour of the environment by 70 gigalitres.

In the senate last February, Labor sided with the Greens and the then Nick Xenophon Team, now the Centre Alliance, to disallow the regulation introducing the change, after bipartisan talks collapsed.

Agriculture Minister David Littleproud approached Labor’s shadow minister, Tony Burke, again and a deal was struck.

In May, when legislation was introduced to recover 605 gigalitres more for the environment in the southern basin – not through reducing irrigators’ allocations but through what are called “efficiency” measures that some scientists question – Labor agreed to back both the legislation and the northern basin changes.

The Greens and the Centre Alliance call that capitulation. Niall Blair calls it collaboration and praises the parties involved for achieving it. He says the meeting of state, territory and federal water ministers in Melbourne in December that finalised negotiations on a way forward in the Murray-Darling Basin proves co-operation is possible.

But the interstate politicking may resume.

“I think the harder stuff is to implement: no doubt,” Blair says.

He accuses the former SA Labor government of playing politics in establishing its own Murray–Darling royal commission last year – an inquiry with which other states and the federal government refused to co-operate fully.

South Australian royal commissioner Bret Walker is due to hand his report to the state governor next week.

The now South Australian Liberal government has promised to release it but won’t say when.

Centre Alliance senator Rex Patrick, who made several trips up the Murray–Darling Basin in recent months, believes the only way to address the issues long term is to scrutinise water entitlements.

“We have to go back to the allocations of water – how much water they’re diverting from the river,” Patrick says. He points to the fact that irrigators and other water users can save or bring forward their allocations over a three-year period.

“That’s not something the environment gets to do. It just misses out.”

He blames internal federal Coalition politics, at least in part.

“There’s nothing the Coalition can do because the National Party won’t let them.”

Despite the compromise reached between government and opposition, partisan politics is also re-emerging.

Opposition Leader Bill Shorten wrote to Prime Minister Scott Morrison on January 13, calling for an urgent inquiry into what he called “an ecological disaster and unfolding emergency”.

Morrison replied, sharing his concern but without an initial commitment to an inquiry– something minister David Littleproud later made.

Duelling scientific reports are now being prepared – one commissioned by Labor through the Australian Academy of Science and the other a government-appointed taskforce.

Both are due next month.

Hydrologist Professor John Williams, of the Australian National University, agreed to join the academy taskforce before the second one was established. He says water management – and climate change policy – are key.

“You can’t have a water management plan that allows you to kill fish every time we have a dry period,” Williams says. “We mustn’t avoid dealing with the fundamentals and that is: how do you manage the river system through climate change and keep the ecological system functioning?”

Meanwhile, the MDBA can’t promise there won’t be more fish deaths.

“We’d like to think not of that size, but there’s certainly going to be a risk,” Glyde concedes.

Alan Whyte remains cynical about both the promises and priorities.

“For 40 years, no one’s thought about the river,” he says. “And even in the basin plan, the Darling River doesn’t rate a mention.”

This article was first published in the print edition of The Saturday Paper on Jan 26, 2019 as "Fish kill: What led to the Murray disaster ". Subscribe here.

Karen Middleton
is The Saturday Paper’s chief political correspondent.