Operation Crayweed is an ambitious and pioneering research project aimed at restoring crayweed forests to Sydney’s reefs, where they once flourished.

These underwater ecosystems are critical for supporting marine biodiversity, providing habitat, food, and shelter for species like crayfish, abalone, and numerous fish.

Beyond restoration, the project also seeks to raise much-needed public awareness about the vital role seaweed forests play in maintaining coastal ecosystems and combating climate change.

Coffin Bay is renowned for its world-class oysters, but few realise that long before aquaculture took hold, the region was home to vast native oyster reefs.

The flat oyster (Ostrea angasi) formed extensive reef structures that supported marine life, stabilised the seafloor, and filtered coastal waters across thousands of kilometers of coastline, and Coffin Bay had some of the biggest reefs.

Native flat oysters were once abundant in the waters surrounding Kangaroo Island. These oysters, known as angasi oysters were once an important food source for the Indigenous people, who harvested them using traditional methods for thousands of years.

However, with the arrival of European settlers in the 19th century, the oyster populations began to decline rapidly due to overfishing, habitat destruction, and the introduction of non-native species.

Seagrass meadows, particularly those formed by Posidonia australis, are highly productive and biodiverse habitats. They play a crucial role in protecting shorelines from erosion and capturing carbon from the atmosphere.

However, coastal development, pollution, and traditional fixed-block-and-chain boat moorings have led to significant declines in Posidonia meadows, creating 'scars' that are unlikely to recover naturally due to the slow growth of the seagrass.

Operation Posidonia calls upon the local community, known as the 'Storm Squad,' to collect dislodged fragments of Posidonia after storms or large tides. These fragments, often viable for re-planting, provide a source of donor material for restoration without harming existing meadows. Anyone using the waterway can contribute to this restoration effort, with drop-off points established for easy collection. 

The initiative serves as a model for how community involvement can make a tangible difference in the fight against environmental degradation, reflecting a broader commitment to ecosystem restoration and conservation.

Seagrasses are vital to the Great Southern Reef, providing essential habitat and storing more blue carbon per hectare than tropical forests. To restore these critical ecosystems, the Seeds for Snapper program—led by SARDI, UWA, OzFish, and volunteers—reintroduces seagrass meadows in degraded areas.

Community members help by collecting and processing seagrass fruits, packing seeds into biodegradable sandbags, and planting them at selected sites. This collaborative model has proven effective in reversing habitat loss and offers a scalable approach to restoration across Australia.

Launched in 2018 in Western Australia's Cockburn Sound and expanding to South Australia in 2020, Seeds for Snapper has grown to include a new partnership between OzFish and the University of Tasmania’s IMAS. Together, they’re conducting Tasmania’s first seagrass restoration trial, testing methods like broadcast and direct seeding, seed bags, and transplanting clumps across varied sediment conditions. These efforts are helping to revive seagrass ecosystems and protect marine biodiversity for future generations.