Ocean stories

Reef Builder: Rebuilding Australia's lost shellfish reefs

A clean ocean, safe coastline, more fish and jobs for regional Australia

Underwater view of Dromana Reef, Victoria
Dromana Reef, VIC Dromana Reef, VIC © TNC Australia

You can help us build 60 reefs

Help us be the first nation to restore the world’s most endangered marine ecosystem

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A bold commitment to build 60 reefs alongside communities who need them most.

We're leading Australia's largest marine restoration initiative, to bring shellfish reef ecosystems back from the brink of extinction - for the benefit of people and nature.

We've demonstrated that shellfish reefs can be restored at scale and their benefits returned. Our bold initiative is rapidly expanding the restoration and protection of the valuable shellfish reef ecosystems. It is allowing communities across Australia to join us in practical conservation efforts where real, local results can be seen.

Together with governments, businesses, and the community, we aim to restore 60 shellfish reefs at 60 locations across Australia, making Australia the first nation in the world to recover a critically endangered marine ecosystem.

Read more on Rebuilding Australia's lost shellfish reef ecosystems.

Reef builder location map
Reef builder locations map Reef builder locations map © TNC

This map shows the current and potential locations for shellfish reef restoration. We aim to rebuild 60 shellfish reef ecosystems across Australia by 2030.  This will see 30% of this lost habitat restored. We are well on our way to achieving that target. We've restored reefs at 23 locations from Perth to Noosa and are now looking at our next phase of work to achieve our 2030 target. 

Quote: Fiona Valesini

We're leading Australia’s largest marine restoration initiative, bringing shellfish reef ecosystems back from the brink of extinction.

Program Director, Oceans

What we’ve achieved since 2021

  • waves


    Hectares of reef restored

  • shells


    Tonnes of recycled shells used

  • fish


    Million shellfish seeded on reefs

  • diver


    Hours of diving for restoration

  • hands


    Volunteers involved

  • clock


    Hours volunteered

  • people


    Jobs created by Reef Builder

  • hand shake


    Small to medium enterprises engaged

You can save shellfish reefs from extinction

Help restore the world's most critically endangered marine ecosystem.

Donate now >

Reefs all over the word are in rapid decline. They’re threatened by global forces such as climate change and local influences like pollution. Our oceans are rapidly changing and it’s hard to not feel in despair about the loss of marine life.

Shellfish reefs are one of Australia’s most critically endangered marine ecosystem. These reefs, made from billions of oysters and mussels, once thrived in over 200 locations in Australia’s bays and estuaries from Noosa in Queensland right around Australia’s southern coastline to Perth in Western Australia. Now less than 10% remain.

Thankfully, shellfish reefs are one ecosystem that we can save from extinction and fully recover. In the process, we can help create hundreds of jobs, opportunities for volunteering, and help sustain our nature-based coastal communities and industries.

at Georges Bay, Tasmania - the last surviving healthy reef of its kind!
Australian Flat Oyster Reef at Georges Bay, Tasmania - the last surviving healthy reef of its kind! © Chris Gillies/TNC

The decline of shellfish reefs

Decades of commercial dredging, pollution and overfishing decimated these vital reef habitats, once home to hundreds of marine species. One shellfish reef type—created by the Australian Flat Oyster—is reduced to just one functioning reef system—at Georges Bay, St Helens in Tasmania.

The loss of shellfish reefs results in the loss of the social and economic benefits they provide to people and nature. Fish stocks decline because fish have fewer places to breed, hide and feed whilst other marine life have no reef areas to colonise. Water quality also declines.

Shellfish such as oysters are excellent natural water filters. One adult oyster can filter up to a bathtub of water a day!

The removal of millions of shellfish caused the loss of a natural process that kept our coastal waters clean and clear. This also put our coastal communities at increased risk. As these reefs provide an important line of natural defence for our coastline—reducing coastal erosion and damage from storms.

Reef Builder funding boost to aid in bushfire and COVID-19 economic recovery

In 2020, an exciting partnership was formed with the Australian Government to continue our work to bring shellfish reefs back from the brink of extinction. 

The economic shocks of COVID-19 and 2019/2020 bushfires were felt by many communities. The Government’s $20 million investment expanded our successful program to rebuild shellfish reefs at 13 locations around the Australian coastline. 

The initiative is set to create up to 170 jobs and engage up to 120 subcontractors, many in regional areas. It will support coastal towns and urban areas in need of recovery from COVID-19 and devastating bushfires.

Rebuilding shellfish reefs can create more jobs than traditional infrastructure investments across a diverse group of industries including maritime construction, aquaculture and natural resource management. 

Jobs range from barge operators, to truck drivers, to shellfish growers and divers. After construction, the reefs will provide public benefits such as more marine life, cleaner waters, more fish and protection from erosion. These environmental benefits help to draw in more visitors supporting eco-tourism, hospitality and fishing sectors in particular.

Reef Builder Reports

  • 2024 Reef Builder Final Summary Report June 2024

    2024 Reef Builder Final Summary Report


  • 2024 Reef Builder Monitoring and Evaluation Report

    2024 Reef Builder Monitoring and Evaluation Report



Benefits of shellfish reefs

Community benefits of shellfish reefs

Shellfish reefs are natural solutions to some of our greatest conservation challebges. Building 60 Shellfish reefs  across 60 locations in Australia can also provide many benefits to people and communities, including:

  • Producing 2.700 direct jobs in maritime construction, aquaculture and science producing ongoing economic benefits for fishing and ecotourism industries.
  • Diverting 7,000m3 of shell waste will be diverted from landfill, to be recycled into new reefs via TNC Australia's Shuck Don't Chuck shell collection program with local restaurants and seafood wholesalers.
  • Partnering with local traditional owner groups and other local delivery partners in the design, construction and monitoring of reef projects.
  • Empowering and directly engaging 2,500 community volunteers in active reef restoration and monitoring activities such as shell cleaning, shellfish gardening and monitoring.

How reefs are built

  1. First, we identify suitable sites for restoration using a combination of science, field surveys, and historical and contemporary knowledge provided by fishers, divers, boaties and scientists.
  2. Next, we create the reef base. We lay natural materials on the seafloor. We often use a combination of limestone rubble and recycled shells, which mimic the foundations of a natural reef. This provides elevation and hard surfaces that attracts marine life. The recycled seafood shells (oysters, mussels and scallop shells) are collected from local restaurants as part of our Shuck Don’t Chuck shell recycling project.
  3. Lastly, when there aren’t enough oysters to allow natural repopulation, we scatter the reef base with millions of baby oysters and mussels grown in nearby hatcheries in partnership with shellfish farmers. These shellfish grow and attach to the reef base and each other. Over time, they create a living reef which further attracts a diversity of fish and aquatic life.

Scientists monitor reefs for several years after construction for threats such as predators and disease. We make adjustments to how the reef is constructed to ensure the reef grows and thrives into a natural, self-sustaining reef. This innovative approach is revitalising reefs from Noosa to Melbourne, from Adelaide to Perth.

The result is less waste to landfill, rejuvenated habitats for native species and improved economic outcomes for local communities. 

Watch the reef builder story

Reefs of Resilience Reef Builder, a unique partnership between the Australian Government and The Nature Conservancy, supported the rapid expansion of restored shellfish reef ecosystems around Australia from 2021 to 2023, building on TNC's previous efforts since 2015.

Download the technical manual

Building better networks for change

The shellfish reefs are designed, built and seeded with baby shellfish in partnership with:

  • Recreational and commercial fishers, diving and fishing clubs
  • Oyster and mussel growers, seafood wholesalers and restaurants
  • Maritime construction labourers and engineers
  • Local communities, schools and Traditional Owners
  • Corporate businesses
  • Natural Resource Management groups

We’ve helped create the Australian Shellfish Reef Restoration Network to bring together restoration practitioners, researchers and the community to help drive the national agenda on shellfish reef research.

Current and past reef-building locations

The Reef Builder project has restored, and is currently restoring reefs in the following 14 sites. More reefs will be added to this list over the next few years:

  1. Noosa River Estuary, QLD
  2. Port Stephens, NSW
  3. Botany Bay, NSW
  4. Wagonga Inlet, NSW
  5. Gippsland Lakes, VIC
  6. Port Phillip Bay, VIC
  7. Derwent Estuary, TAS
  8. Gulf St Vincent, SA
  9. Kangaroo Island, SA
  10. Glenelg, SA
  11. O'Sullivan Beach, SA
  12. Oyster Harbour, WA
  13. Swan-Canning Estuary, WA

Current reef restoration projects across Australia

Click on the points on the map for more information.

Oyster Harbour.
Oyster Harbour
Restoring Albany’s lost shellfish reefs
Port Phillip Bay.
Port Phillip Bay
We are turning the tide on habitat loss in Port Phillip Bay and reinstating our most threatened marine habitat the shellfish reef.
Underwater reef.
Windara Reef
We're rebuilding a shellfish reef across 20 hectares in the Gulf St Vincent. Restoring this reef is critical to improve marine biodiversity, fish production and water quality.
Peel Harvey Estuary
Helping deliver on-ground and in-water environmental actions in consultation with the community, to improve the health of the Peel-Harvey Catchment
Black Swan
Swan-Canning Estuary
Keeping Perth's Swan and Canning rivers healthy and clean by rebuilding the lost shellfish reefs.
Noosa River
Noosa River
The first project of its kind in Queensland to rebuild oyster reefs in the Noosa River.
Adelaide Shellfish Reef
We're bringing shellfish reefs back to the coast of Adelaide where more than a third of the South Australian coastline was once teeming with these reefs and marine life.

Learn more about our shellfish reef restoration projects