Call for Investment Opportunity for Oxygenation Offset Program in Macquarie Harbour (OOPMH) – Science Program |
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| Need |
Macquarie Harbour on Tasmania’s west coast has been a site for Salmonid aquaculture (both Atlantic Salmon, Salmo salar, and Rainbow Trout, (Onchorynchus mykiss)) since the 1980s, however it wasn’t until the early 2000s that standing biomass in the Harbour increased beyond 1000 Tonnes. Across the following decade biomass increased, peaking at just over 20,000 Tonnes in 2014/15 before further increases were halted due to progressive signs of environmental stress in the Harbour. In late 2013 a decline in oxygen levels in the bottom waters of the Harbour was confirmed (Macquarie Harbour Dissolved Oxygen Working Group 2015), and in spring 2016 a major deterioration in sediment conditions was observed (Ross et al., 2017, FRDC 2016-067 ). To reduce the pressure on the Harbour and allow for environmental recovery, the maximum permissible biomass has progressively been lowered by the Tasmanian EPA since early 2017. In May 2020, the biomass limit for salmonids in Macquarie Harbour was set at 9,500 Tonnes, and in September 2022 a Total Permissible Dissolved Nitrogen Output (TPDNO) limit was put in place to replace the standing biomass limit on production. The new determination reduced dissolved nitrogen outputs by approximately 10% compared with 2021 levels. Across this period there has been significant investment in understanding the population status and ecology of the endangered Maugean Skate (Zearaja maugeana) (Bell et al., 2016; Moreno et al., 2020, FRDC 2013-008, FRDC 2016-068). More recently, follow up surveys have indicated potential drops in the relative Maugean Skate abundance, potential Skate mortality events, and the complex relationship with environmental conditions in Macquarie Harbour and oxygen depleted waters (Moreno et al., 2020; Moreno & Semmens 2023) generated substantial concern for the species. This included updating of the current Conservation Advice for the species (DCCEEW 2023), and formation of the National Recovery Team for the Maugean Skate. In late 2023, the Macquarie Harbour Oxygenation Project (MHOP) (FRDC 2023-087) started to trial technological solutions and help address the priority to increase oxygen levels to support the conservation efforts for the Skate and consequently offset the oxygen drawdown from Salmonid aquaculture in the Harbour. Since inception of the MHOP trial, the scientific evaluation program led by the Institute for Marine and Antarctic Studies (IMAS) has made significant progress in assessing the efficacy and environmental response to oxygenation. After demonstrating that the oxygen is delivered and retained at depth, with no adverse ecological effects, the MHOP trial has progressed from initially delivering 500–700 kg of oxygen a day to now delivering close to 4 Tonnes a day (IMAS 2025). This is significant in the context of offsetting the estimated demands of Salmonid aquaculture on bottom water oxygen concentrations, with estimates of oxygen demand in bottom water at current stocking levels ranging from 5 – 18 Tonnes a day (in review). At the broader scale, CSIRO’s hydrodynamic modelling of the main current and mixing patterns in Macquarie Harbour has been used to further assess the feasibility of scaling the MHOP trial and importantly the suitability of mechanically injecting oxygen at multiple locations in the Harbour to offset Salmonid oxygen drawdown. Work with this model demonstrates the likelihood for significant horizontal spread and dilution of oxygen throughout the Harbour and minimal vertical migration throughout the water column when using the same technology and equipment of the MHOP trial. The model has also been used to test multiple release points, again demonstrating the significant horizontal spread, the ideal scenario for gradually increasing oxygen levels, while minimising the likelihood of disturbance to the sediments, considering the stratification of the water column and ensuring a gradual increase. The interim results of the MHOP trial have been presented to government agencies, industry, the community and to the National Recovery Team for the Maugean Skate. These results support the application at scale and the potential to improve oxygen levels in the Harbour. Further innovation in the methodology and implementation of oxygenation have a wide range of other applications for environmental enhancement and remediation. The Australian government through the Department of Climate Change, Energy, the Environment and Water (DCCEEW) have committed funding to offset the oxygen drawdown of Salmonid aquaculture in Macquarie Harbour and help support the conservation efforts for the Skate ( Boosting water quality in Macquarie Harbour | Prime Minister of Australia) . The Fisheries Research and Development Corporation (FRDC) has been contracted by DCCEEW to facilitate the scaling up of oxygenation efforts in Macquarie Harbour and develop a replicable methodology for offsetting oxygen demand from Salmonid aquaculture in the Harbour (the Oxygenation Offset Program in Macquarie Harbour – OOPMH). OOPMH will be delivered in two parts: Supply and Delivery of Oxygenation, and this Science Program, which will deliver on the additional research needed to:
The output of OOPMH will be a ready to adopt methodology that can be replicated to fully offset oxygen demand from Salmonid farming, that has been scientifically demonstrated and ensures no adverse ecological impacts. |
| Deliverables |
The interim results from the MHOP trial demonstrate the efficacy of mechanical oxygenation as a tool to inject oxygen at depth and its potential application at scale. Scaling up of oxygenation is planned under the OOPMH Supply and Delivery of Oxygenation. The successful applicant for this OOPMH Science Program will be required to work with the successful tenderer for the OOPMH Supply and Delivery of Oxygenation to investigate further innovation in the methodology and implementation of oxygenation. This will be underpinned by the following: Guiding, monitoring and evaluating the activities of OOPMH Supply and Delivery of Oxygenation, including oxygen delivery, retention and spatial extent, ecosystem response; Developing a monitoring and assessment framework; and Developing a forecasting and operational decision support tool (DST) that aquaculture managers in the Harbour can use to respond to oxygenation needs in real time. The efficiency and effectiveness of oxygen delivery and environmental response will be assessed and evaluated through the development of a wireless sensor network and sampling program. The DST will utilise the real-time hydrodynamic model of the Harbour developed by CSIRO and sensor network (deployed as part of this Science Program) to optimise the operational requirements of oxygenation in time (when to have it on) and space (where to have it on) based on natural Harbour dynamics (e.g. oceanic recharge, river flows). This information will also be used to guide the delivery of OOPMH Supply and Delivery of Oxygenation. Collectively, the proposed work will support the delivery of a turnkey solution for future operational requirements for oxygenation in Macquarie Harbour, detailed initially in a: 1. Macquarie Harbour Oxygenation Methodology Report, to support commercial salmon farming businesses in Macquarie Harbour to continue offsetting oxygen demand beyond this project’s term. This will include a discussion of engagement with commercial salmon farming businesses in Macquarie Harbour and an update on their readiness to take over supply and delivery of oxygenation. The Macquarie Harbour Oxygenation Methodology Report will be subject to expert review, which will guide the OOPMH Program Board in establishing the scope of a 2. Macquarie Harbour Future Oxygenation Strategy, to be developed as a key outcome of this project Over the last decade and through the MHOP trial, sediments from the Harbour were collected and analysed for different purposes. The Science Program will expand the current understanding of oxygen demand from sediments to develop a 3. Sediment Impact Review and provide Recommendations to the Program Board on the need to develop a 3a. Sediment Impact Mitigation Strategy This aligns with the management strategy and regulation employed for finfish aquaculture in Tasmania. Additional deliverables for this work should also include development of a: 4. Digital System that establishes a central platform or hub that houses relevant data and information pertaining to:
The Salmonid farming industry, such as that intended to be on the Salmon Portal (Home | Salmon Farming Data Portal) 5. Review of social and economic data that informs an independent economic assessment, including but not limited to:
Note – Deliverables 1, 2, 3 and 3a must be presented as standalone reports (please see below for expected timing of these deliverables). |
| Timeline of workplan |
October 2025 – May 2027
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| End User |
Key end-users of the outputs of this work are:
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| Jurisdictions | Tasmania |
| FRDC Themes | Alignment with the Theme(s) from the FRDC RD&E Plan 2025-30 |
| Other |
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All applications MUST be completed via FishNet by 5pm AEST Thursday 9 October.
Applications not submitted by this date may not be accepted unless prior approval for a later submission date is provided by FRDC.
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