Macquarie Harbour is one of Tasmania's most extraordinary marine environments — vast, remote, deep and dark. It is also the home of Tasmania's Salmon farming industry, and for more than three decades the two have shared these waters. Unique harbour geography, with a natural layer boundary known as the halocline, limits the mixing of oxygen-rich surface water into the depths and also prevents oceanic waters flowing into the unique system.
The Australian Government in partnership with industry and scientists are taking on the active role of supplementing dissolved oxygen in those deep waters — and that commitment is now entering a major new phase.
The Macquarie Harbour Oxygenation Project (MHOP) proved that mechanical injection of oxygen into the Harbour's deep waters can improve conditions for seafloor ecosystems, including the habitat of the Maugean skate — an ancient species found on the West Coast of Tasmania.
Following the successful trial phase (MHOP), Salmon Tasmania and its members — Tassal Group, Huon Aquaculture and Petuna Aquaculture are playing a key role in the next step
The Oxygenation Offset Program in Macquarie Harbour (OOPMH) is an Australian Government funded, large-scale operation about to commence, backed by a project agreement with the Fisheries Research and Development Corporation (FRDC) and the Department of Climate Change, Energy, the Environment and Water (DCCEEW)..
The OOPMH has three goals. First, to offset the oxygen demand below the halocline attributable to salmon farming through mechanical oxygenation. Second, to develop a validated and scalable methodology for long-term oxygen delivery. Third, to actively support the health of benthic ecosystems and the habitat of species like the Maugean skate. At the completion of this program the hope is that it will transition full operational responsibility for oxygenation to the industry itself once the program has been validated.
The current design is for three purpose-built modular barges to be deployed across the Harbour, each self-contained with its own power and oxygen generation equipment. Oxygen is extracted from ambient air using proven industrial technology then pumped to targeted depths (15–50 metres) where fine-dispersion nozzles ensure efficient transfer into the water column. Harbour currents carry dissolved oxygen widely, making fixed-location systems energy efficient.
The operational base is the industry's THub facility near Strahan — providing fuel storage, vessel access, maintenance capability and remote monitoring infrastructure, well away from township and public wharf activity.
The combined workforce of the three partner companies exceeds 120 people with deep expertise in remote marine operations, engineering, and environmental management.
Salmon Tasmania's existing solar-powered sensor network continuously monitors dissolved oxygen, temperature, and salinity across the harbour in real time, with data shared with IMAS, CSIRO, and the EPA.
This feeds directly into an adaptive management framework - when natural ocean water brings oxygen-rich water into the harbour, systems can be throttled back; when deep water conditions require greater output, the response is immediate. A parallel FRDC science program (Project 2025-038) tracks ecological response and guides operational decisions.
The industry is responsible for the operational aspects of the program and the IMAS and CSIRO science directs it with regulatory (State and Federal) oversite.
The project carries an explicit commitment to reducing its carbon footprint. Current diesel-powered barges represent the reliable foundation, but the project team is already developing pathways for shore-based electricity generation and subsea oxygen delivery pipelines that if feasible could cut diesel consumption significantly.
At-depth injection systems thatfurther reduce pumping energy are also being evaluated. The goal is an oxygenation system that is not just effective, but efficient and sustainable for the long term.
While the competitive procurement processes were underway for the oxygenation program and science services, separate arrangements were established in July 2025 by the FRDC with Salmon Tasmania to ensure ongoing oxygenation in Macquarie Harbour throughout2025 and early 2026. The oxygenation barge, used during the MHOP, has been operating and delivering oxygen since July 2025 funded by OOPMH.
Salmon Tasmania recognises that Macquarie Harbour belongs to the broader West Coast community. Community engagement continues through the Strahan Community Forum, NRM Cradle Coast, ongoing collaboration with various Aboriginal Corporations, regulators and The Maugean Skate National Recovery Team.
By mid-late 2027 it is forecasted the OOPMH will have generated a full year of large-scale operational data, documented measurable improvements in deep water oxygen conditions, and established the systems, knowledge base and confidence for the industry to operate oxygenation as required in the Harbour.
Detailed reporting will capture everything from barge and system performance to innovation trials and operational learnings — a resource for aquaculture management well beyond Macquarie Harbour.
For the Maugean skate and the wider benthic ecosystem, the measure of success is straightforward: consistently improved dissolved oxygen in the deep waters they call home, maintained by an industry that has chosen to be part of the solution.
It is expected that as the oxygen drawdown from the Salmon industry is offset that other industries will be able to modify how they operate and use the Harbour to maximise the oxygen supply and habitat to this unique system.
Science is already looking at this and there are also a range of other research avenues being planned to look at other aspects like the role of metals from legacy mining pollution play, invasive species, shifting dynamics of potential predators and prey of the skate and the role that climate change might be playing in oxygen dynamics in the Harbour.
The Oxygenation Offset Program in Macquarie Harbour (OOPMH) — FRDC Project 2025-041 — is supported by funding from the FRDC on behalf of the Australian Government.
