South Australia rolls up its sleeves to make reefs for recovery

Last week in Port Adelaide, more than 50 volunteers turned out and got straight to work, recycling 12 tonnes of clean oyster shell into 600 Robust Oyster Baskets (ROBs)—brand new homes for oysters and fish, that will help kickstart the recovery of the local ecosystem.

It was meant to be enough shell for a few workshops. Instead, the crew smashed it out in one go. That’s 600 new oyster reef modules ready to hit the water and start doing what oysters do best—filtering water, improving water quality, and creating vital habitat for fish.

Why now?

Since March, South Australia’s coastline has been hit hard by a harmful algal bloom (HAB). It’s left a trail of dead fish, from large sharks and rays, through to popular rec fishing species like snapper, garfish and whiting. Even the smallest creatures on the food web that our fish depend on have felt the impact.

Oysters, however, can help turn the tide of destruction. They’re surviving the bloom—and that resilience could make them a critical puzzle piece in the state’s marine recovery.

Shellfish reefs once covered more than 800 square kilometres along South Australia’s coast. Today, they’re almost completely gone. Restoring them will help bring fish back, improve water quality, and build resilience against future bloom events.

As OzFish SA Project Manager Brad Martin explains:

“Shellfish reef restoration will be really important moving forward, as we look towards recovery from this harmful algal bloom. Oysters are filter feeders—every day they take algae and nutrients out of the water, which not only helps improve water quality, but also creates the perfect foundation of habitat for fish to return.”

A community-wide effort

The Port Adelaide workshop is just one part of a bigger movement to give South Australia’s fish a fighting chance. Since March, the SA OzFish community has been gathering data to monitor the bloom, bringing awareness to citizen science efforts, and preparing recovery projects in seagrass, mangroves, and saltmarsh—critical nurseries for juvenile fish.

The next big step will be scaling up shellfish reef restoration across the state. A new shell recycling centre is being established in Adelaide, modelled on OzFish’s OysterWorld in Brisbane where volunteers recently hit the milestone of recycling one million kilograms of shell.

Brad says seeing the community turn out in record numbers has been a boost for the whole program:

“It’s really heartening to see so many people roll up their sleeves and get stuck in for the fish and habitats here in South Australia. We can’t do this alone—and the energy we’ve seen from our members gives me confidence we can build something lasting.”

Brad Martin, OzFish SA Project Manager

Oyster reefs are just the start. OzFishers and locals will soon be out cleaning up saltmarsh and mangroves, making sure these vital nurseries are thriving, litter-free and ready to support new life as soon as waters recover. And come summer, the Seagrass for Snapper program will be back—to monitor and restore seagrass meadows that are key to many of South Australia’s fisheries.

How you can help

Whether you’re based in South Australia or watching on from elsewhere, there are ways to make a difference:

• If you’re local, join OzFish as a member and roll up your sleeves at reef-building or clean-up events, or help collect oyster shell for recycling.
• If you’re further afield, you can still back the recovery by donating online or through any BCF store. Every dollar fuels habitat restoration—restoring reefs, seagrass, mangroves and saltmarsh to bring back more fish.