Reef Builder — Restoring Australia's Shellfish Reefs at Gippsland Lakes and Beyond

Australia lost more than 95% of its native shellfish reefs to over-harvesting, dredging and disease over the past two centuries. Reef Builder, a AU$20 million, 2021-2023 partnership between The Nature Conservancy and the Australian Government (with state agencies, First Nations groups, universities and community groups), set out to rebuild them.

Restore shellfish reef habitat nationally while creating jobs and engaging community volunteers, using recycled shell material and native oyster/mussel seeding.

Reefs were rebuilt at 13 project sites across WA, SA, Victoria, Tasmania, NSW and Queensland, seeding around 30 million native oysters/mussels onto 98 tonnes of recycled shell base material. At Gippsland Lakes (Nyerimilang, Victoria), 2.5 hectares across 17 patches were restored in 2022.

The national programme restored more than 40 hectares of reef (since expanded to over 60 hectares), created 425 jobs (2.5x the target), and engaged over 5,200 community members and 305 volunteers. A 2025 survey at Gippsland Lakes, three years on, recorded mature mussel beds, flat oysters, fish, sea stars, crabs and nudibranchs, with reefs filtering millions of litres of water daily. In December 2025 the UN designated Reef Builder a World Restoration Flagship, the first Australian project so recognised.

Independent ecological monitoring beyond citizen-science surveys is limited to a subset of sites, and the programme's AU$14 million/year benefit estimate is explicitly a projected economic figure from delivery partners rather than an independently audited valuation.