Reviving the Shark Bay ecosystem

Shark Bay in Western Australia is home to some of the largest and most diverse seagrass meadows on the planet. But the future of the meadows is under threat, due to human pressure and climate change.

85% of the seagrass cover in the region is Amphibolis antarctica. Amphibolis antarctica reproduces by releasing seedlings with a specialised barb, similar to a squid jig. These seedlings drift in currents and tides until they catch onto substrates, such as reef and existing seagrass, before establishing roots in sediment. 

OzFish and project partner, Perfect Nature Cruises, are deploying thousands of biodegradable sandbags to provide settlement sites for these drifting seedlings. By assisting in the rate of seedling settlement and subsequent survival to maturity, the project will help restore what has been lost and improve the resilience of the ecosystem.

Monkey Mia WA seagrass for snapper project 2025. Seagrass growing from deployed sandbags underwater.
Monkey Mia WA seagrass for snapper project 2025. Diver installing seagrass sand bags underwater.

Seagrass restoration collaboration

OzFish became involved in the project after being contacted by the Ridgley family. The local family, who operate Perfect Nature Cruises in Shark Bay, had seen firsthand the damage to seagrass meadows in Monkey Mia, and how this was negatively impacting the ecosystem.

Vital role of seagrass

The ecosystem services provided by seagrass meadows are numerous and integral to the value of the Shark Bay World Heritage Area.

Seagrass meadows provide habitat and a food source for many marine creatures, particularly those with a high social and economic value. Namely, pink and grass snapper, blue-swimmer crabs, cephalopods, and dugongs. 

Dolphin swimming along boat in Mokney Mia WA
Monkey Mia WA seagrass for snapper project 2025. Boat crew deploying seagrass sandbags.

Preparing for major restoration

So far, the team has deployed 2,000 sandbags back into the Shark Bay Heritage Area, with early results already visible.

In 2025, a further 10,000 bags will be deployed into the area. The restored area will provide a direct ecological benefit to the diverse and unique wildlife that rely on the seagrass meadows for survival, while bolstering the resilience of the ecosystem to stressors, including future marine heatwaves.