Motions

Shellfish Reef Restoration

The Hon. T.A. FRANKS (12:13): I move:

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.

I move this motion in the wake of the algal bloom, an extraordinary event and challenge facing our state and our environment, so I rise today to speak about a really critical and timely matter: the restoration of our shellfish and oyster reef ecosystems and how investing in this natural solution directly supports our state response to the devastating and harmful algal bloom that we are currently seeing in our waters.

Members in this place and the other place who attended the forum I hosted recently called 'Pearls of Wisdom' or the oyster forum, as it was commonly known, which featured ecologist Faith Coleman, marine biologist Anita Thomas, and marine ecologist Dr Dominic McAfee, will be aware of The Nature Conservancy—I can never say it; I always get it wrong so we will call it TNC to save my stumbling over the words—that has done some extraordinary work over recent years, leading national-scale efforts to rebuild shellfish reefs in our littoral zones.

Since 2015, TNC has partnered with the Australian government and state agencies to restore what was once a 'near extinct reef habitat', including more than 40 hectares across 13 projects between 2021 and 2023, under what is called the national Reef Builder program. We know that the government more recently, with the federal partnership, has announced further reef restoration programs, but when you discover that we pretty much have 1 per cent of the reefs that we had precolonisation, you realise that we have a significant challenge ahead of us to restore those reefs.

The goal that has been stated to me is if we could do somewhere between 30 per cent to 40 per cent of what we once had we would be a long way to not just cleaning our seas but cooling our planet, creating a habitat that will keep sand on our shores, restore the seagrasses and filter the seas. In South Australia we do have a challenge before us but we also have a really good reason to be optimistic.

That partnership between The Nature Conservancy (TNC) and the South Australian Department for Environment and Water has already delivered low-profile reef modules at Glenelg, covering 2.1 hectares of shore from our metro coast. Anyone who has seen the underwater photography of what that has done to restore our marine environment will be inspired and hopeful in the face of what is an ecological crisis.

Why is this ecosystem restoration so important? It hardly needs asking, but I will answer it. Oyster and shellfish reefs provide multiple benefits. Firstly, they function as living filtration systems. Oysters and their reef communities remove particles and excess nutrients, and improve water clarity. Secondly, they create a three-dimensional structure on the sea floor offering habitat for fish, invertebrates, and supporting fisheries. Thirdly, they contribute to coastal resilience and help stabilise our shorelines. It is here that we can really clearly see the link to our present emergency.

Many, of course, are really horrified—not just in this parliament but in our community—about the unfolding environmental crisis. A large-scale, harmful algal bloom, dominated by the dinoflagellate Karenia mikimotoi, has been affecting South Australia's coastline since March 2025. The bloom has been attributed to a complex set of drivers but I particularly want to point to the marine heatwave in South Australian waters since September 2024, rising sea surface temperatures and elevated nutrient loads in our coastal waters.

The impacts are severe. Marine wildlife across many species, including fish, rays and invertebrates, have suffered mass mortalities. Water quality has degraded and our fisheries and coastal communities are facing major disruption. In this context, restoring our reefs offers more than just a conservation project; it has to become part of our blueprint for marine recovery and climate resilience.

These reefs can offer us much in regard to harmful algal blooms. By filtering the water and removing the nutrients from the water column and sediments, they will reduce the local nutrient availability that helps fuel algal proliferation. By improving water clarity and depth penetration of light, they support adjacent ecosystems such as seagrass beds, which are themselves critical to ecosystem health.

By enhancing biodiversity and ecosystem complexity, they build resistance into our coastal marine systems so that when events such as the harmful algal bloom do occur, our system has stronger recovery capacity. This is not to suggest that this is the sole solution. Of course, it is not. The primary drivers—nutrient runoff from catchments, warming ocean temperatures and altered hydrology—must also be addressed in parallel, but restoration of oyster reefs is a strategic, tangible and proven part of the solution mix.

Therefore, I have moved a motion today that I hope this parliament will see fit to support. I am certainly open to amendments from opposition, government or crossbenchers that they think might make it more effective, but I think this is one area of addressing the harmful algal bloom that I would hope we could all agree on. At that 'Pearls of Wisdom' forum, we certainly enjoyed eating the oysters, which were incredibly fat and juicy because of the nutrients that they had been consuming, and then put them into a little basket in a bucket which literally will go off to be sanitised, dried out for six months or so, and then, usually with the support of community in particular, end up back on our seabeds, restoring our reefs, providing that habitat, and eventually cleaning and filtering our seas.

I cannot think of a more positive way for the community to come together and for parliament to show leadership than to actually commit to this five-year plan and for all sides of parliament, regardless of their position on the harmful algal bloom causes, to see that this is indeed one of the key solutions. With that, I commend the motion to the council.

Debate adjourned on motion of Hon. I.K. Hunter.