Before dawn on Macquarie Harbour, a workboat idles out from Strahan toward the salmon pens on Franklin and Long Reach, its deckhands checking feed lines before the wind picks up. A few hundred metres away, on the same tannin-stained water, an Institute for Marine and Antarctic Studies (IMAS) research vessel hauls a gillnet it set the evening before, counting whatever Maugean skate — a flat, leathery ray relative that has survived in this one harbour since before Tasmania split from the mainland — happen to be in it. Both boats depend on the same finite resource: the oxygen dissolved in the harbour's dark, layered water. The salmon need enough to grow to market weight; the skate, found nowhere else on the planet, needs enough simply to keep breeding. For a decade the oxygen has been trending the wrong way for the skate, and the two governments that regulate the harbour — federal Labor in Canberra, the Liberal minority in Hobart — have spent that decade managing not the oxygen problem, but the political problem of managing it.
The skate (Zearaja maugeana) has been listed endangered under the federal Environment Protection and Biodiversity Conservation (EPBC) Act since 4 March 2004, and under Tasmania's Threatened Species Protection Act 1995 (Department of Climate Change, Energy, the Environment and Water [DCCEEW], Species Profile and Threats Database). It once lived in two south-west harbours, but a 2022 environmental-DNA survey by UTAS and IMAS found no trace left in Bathurst Harbour/Port Davey, leaving Macquarie Harbour its sole known population on Earth (UTAS/IMAS, eDNA survey, 2022). This topic sets out what the two governments did about that decline, states the industry's strongest case, weighs it against the primary record, and asks what is risked when a government protects an industry from scrutiny rather than resolving the problem the scrutiny exists to catch.
What the two governments did
The story starts in December 2012, when the then federal environment minister approved an expansion of salmon farming in Macquarie Harbour as a "controlled action" under the EPBC Act, but in a "particular manner" that left detailed environmental conditions to Tasmania's own regulatory system rather than imposing federal limits directly (Commonwealth EPBC Act referral decision, Macquarie Harbour Marine Farming Expansion, Dec-2012). That decision — made under a federal Labor government, a decade before Jeremy Rockliff became Premier — is the legal foundation everything since has turned on: the approval environmental groups later asked to have reconsidered, and the approval the current Rockliff and Albanese/Watt governments have each worked to keep in force.
On the state side, EPA Tasmania (the finfish regulator since 2016) tightened its controls as the skate's decline became harder to ignore. From 1 September 2022 it replaced the harbour's standing biomass caps — which farmers could sidestep by timing harvests — with a Total Permissible Dissolved Nitrogen Output (TPDNO) determination, tied directly to the nutrient load salmon farming puts into the water (EPA Tasmania, Macquarie Harbour determination, Sep-2022). On 30 November 2023 it renewed the environmental licences for all ten marine finfish leases in the harbour, held by the three companies operating there — Tassal, Huon Aquaculture and Petuna — for a further two years (EPA Tasmania, licence determination, 30-Nov-2023).
Federally, the Environmental Defenders Office, acting for the Bob Brown Foundation and others, lodged three requests in 2023 asking then Environment Minister Tanya Plibersek to reconsider the 2012 approval under section 78 of the EPBC Act. Plibersek ran a public consultation from 4 December 2023 to 2 February 2024, and by January 2025 her department had reportedly advised her to revoke the approval — forcing a fresh assessment and likely an interim reduction in farming (department advice, reported Jan-2025; The Examiner, "Government 'ignored' advice to halt salmon farming"). She did not act; the decision was deferred repeatedly. Then, on 25 March 2025 — Budget day — the government introduced the Environment Protection and Biodiversity Conservation Amendment (Reconsiderations) Bill 2025, barring reconsideration of a "particular manner" decision once an action had run five years or more under state management. It passed both houses the next day, with Coalition support, in the 47th Parliament's final sitting week before the election was called (Parliament of Australia, Hansard, 25–26 Mar-2025; Environmental Defenders Office, briefing note, Mar-2025). In August 2025, new minister Murray Watt used that law to close out all three requests, confirming the 2012 approval would stand — days before a Federal Court hearing the Bob Brown Foundation had brought was due to begin — paired with an $18.3 million "Oxygenation Offset Program" for the harbour (Minister for the Environment and Water and Minister for Agriculture, Fisheries and Forestry, joint media release, Aug-2025).
Tasmania's government moved the opposite way days later, though not by choice. Rockliff had written to Salmon Tasmania on 2 July 2025 promising the Liberals would "not trade the salmon industry in any way, shape or form" to hold government. Six weeks on, a 5 June 2025 no-confidence motion cost him office and forced a snap election on 19 July 2025, leaving the Liberals largest party but still a minority, with eleven crossbench seats split between the Greens, independents and the Shooters, Fishers and Farmers Party (Tasmanian Electoral Commission, 2025 results). Needing crossbench support to survive, Rockliff announced on 17 August 2025 an immediate moratorium on salmon-industry expansion, a "root and branch" review of its regulation, a commitment to a fully independent EPA, and a new Marine Environment Tasmania Act (Premier of Tasmania, statement, 17-Aug-2025). Salmon Tasmania called it a betrayal; the Australian Workers' Union called it blue-collar jobs sacrificed for a parliamentary majority.
The strongest case
A remote regional economy with few alternatives, and science that is not settled
Strahan and the wider West Coast do not have many other large employers. Mining at Queenstown has shrunk for decades, tourism is seasonal, and salmon farming — pioneered in Macquarie Harbour in the 1980s — is one of the few industries paying skilled, year-round regional wages where the rest of the state's growth has passed by. Statewide, the industry was worth an estimated $1.36 billion in 2024 and says it directly employs around 2,200 full-time-equivalent workers (approx.) (Tasmanian Salmon Industry Plan 2023; industry figures, 2024). Tasmania supplies most of Australia's farmed Atlantic salmon, and frames itself as a food-security asset, not just a jobs one. On the science, it makes a genuine point: Macquarie Harbour was already naturally low in oxygen before any farm existed — a strong halocline, limited flushing, a century of Mount Lyell mining pollution and altered Hydro Tasmania river flows — so untangling how much stress farming itself adds is genuinely difficult, and industry-aligned commentary argues campaigners need only assert a risk, not prove one, to trigger years of limbo (IPA, "Skating Over Thin Evidence," 2025). On that view the industry has not stood still — it co-funded the original oxygenation trial, and has operated under the EPA's tightened nitrogen cap since 2022 — and reopening a twice-reviewed approval indefinitely offers it no certainty to invest and keep its workforce employed.
The evidence
The skate's own numbers are the place to start, since every other decision here turns on them. IMAS's Maugean Skate Monitoring Project — the primary scientific record — found relative abundance fell by roughly 47 per cent between 2014 and 2021 (approx.), and the federal Threatened Species Scientific Committee's 2023 conservation advice concluded the species faces a high risk of extinction, driven overwhelmingly by degraded water quality and specifically reduced dissolved oxygen (IMAS, Maugean Skate Monitoring Project; Threatened Species Scientific Committee, Conservation Advice for Zearaja maugeana, 2023–24). The advice names salmonid aquaculture's oxygen demand, on top of the harbour's older mining and hydro-flow disturbances, as the threat most within reach of a fast fix — and names reducing farmed biomass as the fastest route to it. That is the scientific case the 2012 approval never had to answer to directly, since it deferred conditions to a state system that took another decade to introduce a nutrient-based cap.
The employment numbers, by contrast, are genuinely contested, and the gap matters because it sits at the centre of the "regional jobs" case. Industry figures put direct statewide employment at roughly 2,200 full-time-equivalent positions (approx.), but a November 2023 analysis of ABS census data by the Australia Institute — a secondary, left-of-centre source whose figures industry disputes — found closer to 1,722 people employed statewide, and calculated aquaculture at about 4.2 per cent of West Coast employment, against the roughly 17 per cent industry has claimed for that region (Australia Institute, "Small fish, big pond," Nov-2023). Both figures can be roughly true depending on what is counted, direct against flow-on, statewide against West Coast-only, but the spread is wide enough that neither government has settled on one audited number before legislating to protect the jobs it describes.
A regulatory approval eleven years old was never reopened on the science. It was closed off, in a single day, on the parliamentary calendar.
The critique
The clearest problem with the federal government's handling is the sequence, not any single decision alone. A minister's own department reportedly recommended revoking the 2012 approval in January 2025. Rather than accept or reject that advice on its merits — a decision the EPBC Act's reconsideration power exists precisely to allow — the government rewrote the power itself, on Budget day, and passed the rewrite through both houses in roughly a day, cutting off the pending requests before they could be decided rather than deciding them. That is a materially different act to weighing the evidence and choosing the industry: it is choosing not to weigh the evidence at all, on a law that exists to protect species with no other advocate in the room. The Environmental Defenders Office's finding that the Bill received "minimal parliamentary scrutiny" is not a partisan characterisation; a bill introduced and passed within about 24 hours, affecting a live Federal Court dispute, is objectively rushed by any ordinary legislative standard (Environmental Defenders Office, briefing note, Mar-2025; Parliament of Australia, Hansard, 25–26 Mar-2025).
Tasmania's handling compounds rather than offsets that problem. Having spent years defending the 2012 approval's downstream state licensing as adequate — including a two-year licence renewal in November 2023, weeks after the federal reconsideration requests were lodged — the Rockliff government reversed itself within six weeks of an explicit written promise not to, and did so as the price of political survival rather than any new scientific finding. Whatever the merits of the resulting moratorium, review and promised Marine Environment Tasmania Act, the sequence tells West Coast workers and the salmon companies that state policy currently turns less on the EPA's monitoring data than on which crossbench votes a Premier needs that week. An industry told for years it would never be "traded" cannot reasonably be told the review that followed was planned rather than extracted.
What both governments got right
A fair audit credits what the record shows, not the harshest reading of it. Both governments can fairly say the skate has not gone extinct on their watch: the industry has cut its nitrogen footprint under the EPA's tightened cap since 2022, and IMAS's latest monitoring, as at 2026, shows relative abundance rising for a second consecutive year alongside measured gains in dissolved oxygen (IMAS, Maugean Skate Monitoring Project, third report, 2026). Tasmania's August 2025 commitments — a moratorium, a genuinely independent EPA, a dedicated Marine Environment Tasmania Act — are substantive if delivered in full, going further than the state offered the skate in the previous decade. But an early recovery sign in a population that fell by roughly half over seven years is not proof the pressure has gone, and it sits alongside a federal government that answered a still-live legal question by making it unaskable. A species with one population, in a harbour where oxygen can shift sharply after a single still, warm summer, has little margin for a government to get its sequencing wrong twice.
The risk to the future
An extinction that cannot be undone, and a legal shortcut that may not hold
Two risks sit on top of each other here, both irreversible. The first is biological: the skate has no other wild population, and no captive-bred release program mature enough yet to be a safety net at scale — a genuine, world-first captive hatching at IMAS's Taroona facility in 2024 remains an early-stage insurance policy, not a substitute for a healthy harbour. The Conservation Advice's own language, that the species is close to "one extreme hypoxic event from extinction," is the Commonwealth's own scientific committee, not campaign rhetoric. A bad summer, a mining discharge or a run of still weather dropping oxygen sharply in a high-biomass year leaves no second population to fall back on, and no funding can reverse an extinction after the fact. The second risk is institutional and outlasts this industry: a national environment law amended on Budget day, in about a day, specifically to stop a minister answering a live question about one company's approval, is a precedent other industries will now expect too. The Bob Brown Foundation has flagged a fresh Federal Court challenge arguing the new law does not validly cover this case, and conservation groups have separately lobbied UNESCO, warning salmon farming threatens values within the adjoining Tasmanian Wilderness World Heritage Area — a listing worth far more to Tasmania's economy, in tourism terms, than the industry the government moved to protect (UNESCO World Heritage Centre correspondence, 2024–26, as reported by the Australia Institute and Environmental Defenders Office). If either challenge succeeds, the certainty both governments bought at the cost of scrutiny will turn out not to have existed at all — leaving the skate, the workforce and Tasmania's wilderness brand all still exposed, with a year or more of legal and reputational cost on top.