During Australia’s first decades as a British colony, oysters were so cheap and plentiful that settlers used their ground-up shells to pave roads. Today the country’s shellfish reefs are nearly gone. Overexploited to the point of collapse, they are now Australia's most threatened marine ecosystem.
It’s a similar story across the world. Globally, 85 percent of shellfish reefs have either disappeared or been severely degraded.
That’s why TNC Australia is embarking on the country’s largest-ever marine restoration initiative. Our goal is to build 60 shellfish reefs across the country, each several hectares in size, that will restore 30 percent of this lost habitat and return it from the brink of extinction.
Construction is already underway at 13 locations, supported by the Australian Government’s Reef Builder initiative and by state and local governments, businesses, philanthropists, and local communities.
So how exactly do we build a shellfish reef?
First, we create the reef base by installing limestone rubble on the seafloor. In some areas, we add oyster, mussel and scallop shells recycled from local seafood restaurants and wholesalers. Then we seed the base with millions of shellfish grown at nearby hatcheries or aquaculture leases.
TNC pioneered this reef-building technique more than 15 years ago in the United States. Our Australian team is expanding on that knowledge to create a restoration framework that can be used in other temperate ecosystems, including Hong Kong and New Zealand.
Healthy new reefs will help filter and clean water in our bays and estuaries, provide habitat for fishery species and other marine life, and create jobs in regional communities. The Australian government invested AUD$20 million in the project as part of their COVID-19 pandemic recovery efforts.
Protecting and restoring shellfish reefs will make Australia the first nation in the world to recover a critically endangered marine ecosystem.
To learn more about reef restoration in Australia, visit natureaustralia.org.au.
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Restoring shellfish reefs
Shellfish reefs are Australia’s most critically endangered marine ecosystem. Made up of billions of oysters and mussels, they once thrived 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.