The critically endangered Maugean skate is talked about more often than seen.
A quadrangular ray-like species, it has survived in brackish water on the bottom of Macquarie harbour – an immense body of water on Tasmania’s sparsely populated west coast – for tens of thousands of years. It is not found anywhere else.
The number of surviving skate is not clear, but a monitoring report estimated the population slumped by 47% between 2014 and 2021 after a sharp drop in dissolved oxygen levels in the harbour due to human activity and a heavy storm. Scientists say it means the species could be one extreme weather event from extinction.
After receiving scientific advice that aquaculture was having a “catastrophic” impact on the species, the Australian environment minister, Tanya Plibersek, agreed with an environment group request that she should formally reconsider salmon farm licences in the harbour.
A governmental scientific committee on threatened species recommended action before summer, including reducing the number of salmon, but that didn’t happen. Nearly six months later, the reconsideration process is ongoing.
Environmentalists and salmon industry leaders don’t agree on much, but both are asking the same question: when will it be resolved?
A political bomb
Plibersek last week told Guardian Australia that the government had received more than 2,500 submissions and was carefully considering all information to ensure a “proper, legally robust decision” was made. Meanwhile, the skate and the future of salmon farming in the harbour is the focus of increased attention on multiple fronts.
The UN Educational, Scientific and Cultural Organisation (Unesco) has written to the Albanese government asking it to respond to concerns raised by scientists and environment groups about the impact of fish farms on Tasmania’s world heritage wilderness area, which covers about a third of Macquarie harbour.
At this stage, it is an information collection exercise. Once the government responds, bodies that advise the World Heritage Committee will be asked to review the evidence and see if there is an issue to be addressed.
In Tasmania, where both major parties argue the $1.3bn salmon industry is vital to the state, the reconsideration process has set off a political bomb.
The scale of political support for the state’s three foreign-owned salmon companies – Tassal, Huon Aquaculture and Petuna – was underlined on Saturday, when the Liberal premier, Jeremy Rockliff, and the Labor opposition leader, Dean Winter, both signed an open letter urging the prime minister, Anthony Albanese, to “end the uncertainty” and deliver a “positive decision” for the industry.
The letter, published as an ad in local newspapers, was organised by the industry lobby group Salmon Tasmania. It pointed to comments Albanese made during a visit to Tasmania in January, including that he believed salmon farming in Macquarie harbour had a future and he supported “maintaining your jobs”.
The Maugean skate wasn’t mentioned. The closest the signatories – including Liberals Jonno Duniam and Eric Abetz, state Labor MP Janie Findlay, independent senator Tammy Tyrrell and local mayors – came to addressing the extinction risk was to say the federal government had started the reconsideration process “in response to pressure from environmental activists”. They said the delay in having it resolved was “affecting people’s mental health, community morale and investment decisions by businesses right across Tasmania”.
The letter was an amplification, but is consistent with previously held positions. Rockliff has declared the Liberals will protect salmon jobs “at all costs”, while Winter spent his first day as Labor leader in April visiting the town of Strahan, on the banks of Macquarie harbour, arguing that “jobs in industries like aquaculture” were critical to the state and his party “won’t stop standing up for them”.
An ‘insurance policy’
Amid the jobs-focused political pressure, the skate had some cautious good news. The University of Tasmania’s Institute of Marine and Antarctic Studies (Imas) last year began a government-funded captive breeding program, moving four adults and 50 eggs from the harbour to a facility in Hobart.
Two adults – one female and one male – died, but the remaining female has since laid 54 eggs, and 19 baby skates have hatched from the eggs brought from the wild.
The head of the program, Prof Jayson Semmens, says it has been a stressful, hazardous process – “there’s a lot of weight on our shoulders” – but some babies are now beyond the three-month age that suggests they have a good chance to survive.
“If nothing else it’s an insurance population,” Seemens says. “The species has been around as long as the dinosaurs, but in a very short time we’ve put it at risk, so the onus is on us to do everything we can.”
The ultimate goal is to release captive bred skates into the wild, but that is some way off. Semmens says it is too early to say when it might be possible, or where it might happen. “We’re not ready yet. You need to remediate … oxygen levels in Macquarie harbour before you would introduce any animals there, and that’s a big job that needs thought and planning,” he says.
Reoxygenating water
No one suggests the captive-breeding program solves the problems facing the species, which are caused not only by fish farms, but also hydroelectricity generation altering upstream river flows and rising temperatures due to the climate crisis.
Scientists have also been trialling improving oxygen levels in the harbour by using a modified barge to pump reoxygenated water 30 metres below the harbour surface.
Jeff Ross, a senior researcher at Imas who oversees the project, says that will be scaled up from a current level of 2 tonnes a day as the industry and government-funded $7.2m trial continues. He says he is hopeful about what it could achieve, and that saving the skate is going to take “a whole of different stakeholders and different angles”.
“I’m probably more optimistic than I was six months ago, when we didn’t even know whether we could captive breed and we didn’t know whether oxygenation was even feasible,” Ross says. “The trial is looking promising quite quickly, but we are aware that questions on fuel usage and sustainability will be raised and this is a key focus for the project.”
Plibersek gave her view on the oxygenation trial in a letter to Rockliff in November. She described it as a “positive step forward”, but suggested that “on its own, it will not be enough to solve the problem”.
The minister, who has set a national target of zero new extinctions, used the letter to set out her starting position: a skate recovery team had found there would need to be better regulation and monitoring of what she called “lower salmon farming industry loads”. She suggested if action was not taken now, the people working in the industry could ultimately suffer through more drastic change later.
Salmon industry ‘denying science’
The industry says 395 positions directly or indirectly rely on the Macquarie harbour salmon industry.
A freedom of information request by the Australia Institute, asking for submissions relating to the reconsideration process, revealed a more specific number from the three salmon companies. Combined, they said they had 109 full-time equivalent jobs in the Strahan area, though not all lived locally.
Macquarie harbour is a relatively small part of the state’s salmon industry, compromising just 13% of production. The industry and its political backers argue that doesn’t reflect the role the industry plays on the state’s small west coast community.
The Tasmanian director of the Australia Institute, Eloise Carr, who lodged the information request, argues leaders need to act based on evidence, not politics, and that governments should step in to support workers affected by necessary change.
She says it is “completely inexplicable” that Plibersek has not yet made a decision, “shocking” that Rockliff and Winter signed an industry letter that dismissed science-based concerns as activism, and that the-oxygenation trial is about justifying the salmon industry, not rehabilitating the harbour.
“The salmon industry is behaving in the same way as the fossil fuel industry in denying the science. Unfortunately the major political parties appear to be jumping on board with that,” Carr says.
Salmon Tasmania’s chief executive, Luke Martin, argues “no one is denying the science”. He says the organisations that prompted the reconsideration, including the Bob Brown Foundation and the Environmental Defenders’ Office, have an anti-salmon farming agenda.
“The reality is we’re doing this [reconsideration] process due to their activism,” Martin says. “We fundamentally disagree with them, and think the issues facing the skate are much deeper than salmon.”
At a press conference in Launceston on Saturday, Albanese was asked when a decision on the Macquarie harbour salmon farms would be made.
He began by saying: “Tassie salmon is the world’s best, I like eating it and I like the fact that jobs are created by growing it.”
But he also said there were environmental processes that the government to go through, and the law needed to be applied. “That will be happening in this case,” he said.
• This article was amended on 15 May 2023 to clarify that the oxygenation trial was jointly funded by industry and government.
