Motions

Shellfish Reef Restoration

Adjourned debate on motion of Hon. T.A. Franks:

That this council—

1. Acknowledges the urgent and ongoing threats to South Australia's marine environment and economy;

2. Recognises the critical role of large-scale shellfish reef restoration in improving water quality and system resilience;

3. Commits the state government to the development of a five-year 'South Australian shellfish reef acceleration plan', focused on expanding reef restoration to priority geographies—particularly the Gulf St Vincent region, Spencer Gulf and metropolitan coastal waters—and linked with localised monitoring, nutrient-reduction strategies and stakeholder partnerships;

4. Tasks the relevant minister to report back to the council within six months on the progress of reef restoration efforts, including area restored, intended to be restored, partners engaged, budget profile and measurable ecosystem outcomes; and

5. Actively encourages collaborative investment from the commonwealth, philanthropic and private sectors to scale reef restoration in South Australia, leveraging the national Reef Builder model and local partnerships.

(Continued from 29 October 2025.)

The Hon. N.J. CENTOFANTI (Leader of the Opposition) (12:47): I rise to speak in support of the motion from the Hon. Tammy Franks. It is a timely and constructive contribution to the parliament's work on restoring the health of South Australia's marine ecosystems, a work that is essential not only for our environment but for the long term prosperity of coastal communities and the sustainability of our state's fisheries.

This motion is consistent with the opposition's long-term environmental and economic priorities. It reflects the principles contained in our evidence-based Save Our Seas policy platform, with marine restoration recovery that is grounded in science, supported with transparent reporting, and delivered through partnerships that combine public and private investment. South Australian waters are among our state's greatest natural assets, and we believe that future generations deserve a marine environment healthier than the one we inherited.

When shellfish reefs are re-established in biologically suitable locations the ecological benefits are extraordinary. These restored reefs filter and clean vast volumes of water, remove excess nitrogen, build richer and more complex food webs, and support recovery of fish stocks that our recreational and commercial fishers depend on. They are nature's own water treatment systems and fisheries recovery mechanism rolled into one.

However, as this motion notes, success requires ecological care. We must avoid monocultures and instead ensure, quite simply, that the right shellfish are placed in the right locations. This means species-appropriate and site-appropriate restorations that rebuild functioning biodiverse ecosystems, not just structures on the seabed. This approach reflects the national Reef Builder principles and is fully aligned with the scientific recommendations of the federal Algal Blooms in South Australia report.

Importantly, the intent of this motion aligns closely with existing Liberal commitments. A future Liberal government has already outlined a $30 million Save Our Seas initiative to accelerate reef restoration and deliver a further 50 hectares of limestone shellfish reefs across the state. Our long-term vision is ambitious but achievable: to restore South Australia's shellfish reef systems to something approaching their pre-20^th century extent. To scale this work we have called for an 80:20 co-investment partnership with the commonwealth government to enable an additional 200 hectares of reef restoration.

With the state and federal governments' withdrawal from hosting COP, we reiterate our call for the redirection of that funding towards an immediate and substantial commonwealth investment in the order of $500 million to accelerate reef restoration nationally and particularly in South Australia. This would deliver enduring environmental outcomes, genuine economic stimulus and a legacy of national significance.

I also want to acknowledge the many citizen scientists, coastal groups, local volunteers and community organisations who have been central to marine monitoring and habitat recovery for decades. Their contribution is a cornerstone of this state's environmental stewardship. Strengthening their role through localised monitoring, transparent reporting and nutrient reduction strategies is not only appropriate; it is essential. The opposition has been consistent in its belief that rebuilding marine health requires ongoing, independently verified science and long-term investment, not piecemeal or politically reactive measures.

Finally, the motion's requirement for the minister to report on progress, area restored, partnerships established, measurable ecosystem outcomes and budget trajectory is both sensible and strongly supported. Accountability is essential for the parliament, good for communities and good for the environment. Clear, regular performance reporting is entirely consistent with the opposition's longstanding calls for improved transparency in marine management and the operation of government in general.

For all those reasons—the environmental necessity, the economic opportunity, the community support, the scientific foundation and the demand for accountability—the opposition is pleased to support this motion. By doing so we help ensure that South Australia leads the nation in the restoration of shellfish reefs and the recovery of our precious marine ecosystem. I commend the motion to the chamber.

The Hon. R.A. SIMMS (12:51): I rise to support the motion, and I thank the honourable member for putting it forward. This is certainly timely, particularly when one considers the toxic algal bloom that has devastated our marine ecosystems, causing over 90,000 recorded marine deaths across more than 700 species since February 2025. There can be no question that we are facing the biggest ecological catastrophe in our state's modern history. The government needs to do more to restore biodiversity and the ecosystems that have been devastated by the toxic algal bloom.

The impacts have rippled through the fishing, aquaculture and tourism industries and have impacted on our coastal communities, and the effects have been absolutely devastating. The government must commit to a longer term plan to restore shellfish reefs across our coastal waters. In terms of its establishment, an artificial shellfish reef can take three to five years to reach maturity. Oysters can filter up to 100 litres of water each per day, helping keep our oceans' waters cleaner. This is a practical and tangible project that could improve the health of our oceans.

I therefore call on the government to urgently expand the artificial reef restoration projects to increase the resilience of our oceans and coastal waters. This is needed now more than ever, as the effects of climate change will increase the severity and frequency of these events. I commend the motion.

The Hon. R.B. MARTIN (12:53): I rise today to speak on behalf of the government in support of this motion and thank the Hon. Tammy Franks for providing this opportunity. The honourable member is right when she says that the ongoing threat to our marine environment is an issue that goes to the heart of one of the most pressing environmental challenges facing South Australia.

As this motion states, these challenges are urgent. The threats they pose to our marine ecosystems must be resolved. South Australia's oceans are among our most valuable natural assets. They sustain our fisheries, aquaculture, tourism and recreation industries in metropolitan communities as well as our regional and remote coastal towns. They also underpin the health of the Gulf St Vincent, Spencer Gulf, the Coorong and our entire marine environment.

The Nature Conservancy (TNC) along with the Department for Environment and Water have already delivered low-profile reef modules at Glenelg. Kangaroo Island and O'Sullivan Beach are part of this Reef Builder project. We know that these waters have faced many accelerating pressures. These threats are visible in the diminished resilience of our gulfs and other key coastal zones. It is within this context that shellfish reef restoration becomes essential.

The Malinauskas government knows that coordinated, targeted and ambitious action is essential. Central to the honourable member's motion is a clear commitment to the development of a five-year shellfish reef acceleration plan for South Australia, a plan that this government supports and is committed to.

The state and federal governments have invested $2.6 million in total for community-based shellfish restoration. This includes an initial $800,000, followed by a further $1.8 million of funding from the state and federal government's Algal Bloom Summer Plan, which includes the building of 25 community shellfish reefs. Such coordinated planning ensures we scale up restoration to the level required to make a long-term difference.

This government wants to ensure progress is measurable, transparent and accountable. We have committed to real action and are working toward solutions. By accelerating shellfish reef restoration, we are investing in cleaner water, more resilient gulfs, stronger fisheries, improved biodiversity, and a healthier future for generations of South Australians. The government supports this motion because it charts a clear and responsible path forward.

The Hon. T.A. FRANKS (12:55): I rise to thank those speakers who have made a contribution to this motion: the Hon. Nicola Centofanti, the Hon. Robert Simms and the Hon. Reggie Martin. Indeed, shellfish reefs—hard to say, good to do. I am glad it is not just me who decided not only that The Nature Conservancy (TNC) needs to be congratulated, but perhaps it is better to use the acronym.

The concept of shellfish reefs is hardly a new concept. In fact, Aboriginal people had successfully looked after and lived from native shellfish reefs for 80,000 years before white colonisation. Within decades, however, the reefs were declining after colonisation, and by the 1890s, here in South Australia, they were collapsing. Globally, there remain now less than 1 per cent of the oyster reefs that this globe once had. That is extraordinary: just less than 1 per cent.

The Murray Basin was once a shallow inland sea or estuary, which reached well over 100 kilometres inland, and here, too, oysters and other shellfish thrived. Indeed, fossilised reefs survive in the Murray Basin to this day. Some of them are 75 to 100 metres long and six to eight metres thick. By destroying our native oyster reefs through a combination of overharvesting, damaging them through mechanical dredging, and removing shells to be burned for lime in the production of mortar and cement—and it has been pontificated that perhaps some of that mortar and cement might hold this building together—we have destroyed the incredibly complex ecosystems that depended upon them as the foundation species.

No doubt some of the oyster shells removed from along our own coastline have indeed ended up in this building, and while they hold Parliament House together, oysters cannot spawn on the seafloor without them. Indeed, it might not sound like much, but the damage from the removal of those shells plays a key part in the collapse of our naturally occurring reef. Oysters, in particular, need to colonise, and need the shells of their ancestors. They cannot simply settle on the floor, but build it and they will come. We have seen it at Glenelg and on the Windara Reef where local restoration projects are doing really well.

Globally, reef restoration projects have been successful right across the world: here in Australia of course, New Zealand, Chesapeake Bay in the US, and the North Sea. Indeed, we have also seen really successful projects off the German and Dutch coasts. This is having an impact. They are cleaning the water, they are increasing biodiversity, they are capturing carbon and protecting our coastlines from the impact of climate change.

The combination of critically important services that they provide includes baffling. I have a note here 'or absorbing' if the use of the term 'baffled' has you feeling slightly baffled. They are baffling wave energy, protecting shorelines from sea level rise and erosion, cleaning the water, removing nutrients that can contribute to toxic algal blooms, and reducing the impacts of sea level rise and increasingly frequent storms.

They provide both habitat and food, they increase fish production, they grow vertically and densely, and cram a huge amount into a small footprint. Stable coastlines, of course, are better able to support coastal wetlands and mangroves which are 50 times more effective than sequestering CO₂ than forests are. Of course, this is of increasing importance as our land-based carbon stores are vulnerable to being wiped out, and are releasing more carbon into the atmosphere via bushfires. Without taking into account carbon sequestration services, a 2012 study valued the ecosystem services provided by oyster reefs—if money is your thing—at $US99,000 per hectare per year. Finally, a recent Insurance Council of Australia report found that resilience spending returns $9.60 for every dollar spent.

If we are serious about supporting our coastal communities, tackling climate change and valuing the waters that, in addition, contribute so much to our mental and physical health, we must continue to be the strongest possible advocates we can be for critically important work such as this. I welcome the approach that has been taken here today. There has truly been cross-party support, and that is the support we need if we are to have a future. With that, I commend the motion.

Motion carried.

Sitting suspended from 13:00 to 14:16.