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Ocean stories

Reversing the threat

Restoring Australia's lost shellfish reefs

Australian Flat Oysters The Nature Conservancy's Simon Branigan shows off some Australian Flat Oysters growing at Margaret's Reef, Port Phillip Bay, Victoria © Jarrod Boord / Streamline Media

Each hectare of oyster reef built will return many benefits to the local marine environment and communities
Shellfish reef infographic Each hectare of oyster reef built will return many benefits to the local marine environment and communities © TNC

Shellfish reefs – vitally important ecosystem engineers

Shellfish reefs are natural solutions to some of our greatest conservation challenges. They have vast water filtering capacity, boost fish stocks, provide homes for abundant sea life and safeguard Australia’s coastal communities and shorelines from erosion.

They also work in tandem with other coastal habitats, such as seagrass beds and kelp, generating vital ecological connections that strengthen natural coastal resilience. Shellfish reefs are created when millions of oysters and mussels settle onto each other forming hard reef structures or beds in Australia’s bays and estuaries.

These vibrant reefs function just like their more colourful cousins, coral reefs, providing food and habitat for fish and other marine life.

of Australia's natural shellfish reefs remain
Less than 10% of Australia's natural shellfish reefs remain © The Nature Conservancy Australia

The tragic decline of shellfish reefs

Until the start of the 20th century, Australia was home to vast shellfish reefs, stretching across the southern half of the country, and as far north to at least the southern tip of the Great Barrier Reef and up to the mid-west coast of Western Australia

These reefs have been largely decimated by wild commercial harvest, sedimentation, water pollution, introduced species and disease, our natural shellfish reefs have virtually disappeared.

The disappearance of these reefs from much of Australia’s coastline has changed how our coastal ecosystems function, with a host of negative flow-on effects such as reduced water quality, fish abundance, natural shoreline protection, livelihoods and socio-cultural connection to our waterways.

The Nature Conservancy is rebuilding Australia’s lost shellfish reef ecosystems

Shellfish reefs are natural solutions to some of our greatest conservation challenges. Thankfully, shellfish reefs are one ecosystem that we can save from extinction and fully recover.

The Nature Conservancy’s (TNC’s) shellfish reef building program is Australia’s largest marine habitat restoration initiative. It aims to rebuild 60 shellfish reef ecosystems across Australia by 2030. This will see 30% of the geographic locations this habitat once existed restored, bringing back an entire ecosystem from the brink of extinction and bolstering the resilience of our bays and estuaries for people and nature.

 

TNC leading the journey towards restoration

Timeline The Great Southern Seascapes Program © The Nature Conservancy Australia

The Great Southern Seascapes program

To reverse decline and scale-up the restoration of other coastal habitats, TNC established the Great Southern Seascapes program in 2015 through an initial $3 million grant from The Thomas Foundation.

Port Phillip Bay in Victoria was the first restoration project location established in Australia, followed by Windara in the Gulf St Vincent in South Australia, then Oyster Harbour in Albany, Western Australia.

In Queensland, The Barbara Thomas Fellowship funded a historical ecology study in the Noosa River. This was instrumental in establishing the ‘Bring Back the Fish’ shellfish reef restoration trial funded by The Thomas Foundation and a precursor to the Noosa Reef Builder project.

Crucially, these projects demonstrated that shellfish reefs can be restored at scale and their social, economic and ecological benefits returned to coastal communities.

Thumbnail_2024 Reef Builder Front cover of 2024 Reef Builder Final Summary Report © TNC / Australian Govertment

Reef Builder: Australia’s largest marine restoration initiative

Reef Builder was a partnership between TNC and the Australian Government and has supported Australia’s largest marine restoration initiative to date. This $20 million Program sought not only to restore near-extinct shellfish reefs at 13 project geographies across southern Australia, but also to provide much needed economic stimulus to regional and metropolitan economies impacted by the COVID-19 pandemic, and those devastated by the 2019 bushfires.

Delivered between 2021 and 2023 in collaboration with government, natural resource management organisations, industry, First Nations groups, community groups, recreational fishers and universities, Reef Builder has restored over 40 hectares of lost shellfish reefs across 13 projects spanning Western Australia, South Australia, Victoria, Tasmania, New South Wales and Queensland

Read more on the amazing national and local impact of Reef Builder.

Success in rebuilding the reefs

Combined with the shellfish reef restoration initiatives delivered by TNC and partners since 2015, a total of 21 shellfish reefs covering a restoration area of 62 hectares have now been restored across southern Australia. This is a considerable advancement towards TNC’s broader goal of rebuilding 60 reefs across Australia by 2030 and recovering 30% of original geographic locations where these habitats once existed.