Bags away! Monkey Mia seagrass restoration launched in Shark Bay World Heritage Area
OzFish Unlimited has begun an ambitious new seagrass restoration project working with local partners Perfect Nature Cruises in Shark Bay, Western Australia.
Shark Bay is home to some of the largest and most diverse seagrass meadows on the planet and they have come under increasing threat from anthropogenic forces, particularly the changing climate.
A marine heatwave and extreme rainfall event in the summer of 2010-2011 caused significant stress resulting in a decrease in the resilience of the Amphibolis antarctica meadows which account for 85% of the seagrass cover in the region.
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.
By assisting in the rate of seedling settlement and subsequent survival to maturity, the project will help restore what has been lost and to improve the resilience of the ecosystem to future disruption. 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.
The project will seek to enhance the survival of A. antarctica seedlings by providing a biodegradable substrate upon which they can settle and grow. The stable substrate provided by hessian bags has been shown to increase seagrass density and growth rates in a multi-year study on the same species in South Australian waters (Tanner, 2015).
OzFish became involved in the project after being contacted the Ridgley family who operate Perfect Nature Cruises in Shark Bay. The long-time local family had seen firsthand the damage to seagrass meadows in Monkey Mia and how this was impacting the ecosystem.
“I was confident that Shark Bay’s seagrass required action, but we needed the right support to make it happen.” said Greg Ridgley. “We know OzFish has a track record in similar projects, so together we’ve been able to turn our vision into reality and make a real difference.”
OzFish Program Manager for WA, Steve Pursell, has been coordinating the efforts and believes the project is another great example of OzFish working with local partners and stakeholders.
“Shark Bay is almost as far west as you can reach on the Australian mainland- it’s a stunning and beautiful location but it is very isolated. This is why we are lucky to partner with passionate locals who know these waters so well and have networks in place to get the job done, they also have the perfect vessel for the work”.
Skipper Liam Ridgley has dedicated the past year to preparing the Norwest Lady, a 12m diesel jet boat with a shallow draught of 30cm, for seagrass restoration and scientific monitoring in Shark Bay. This meticulous outfitting ensures minimal impact on both new and established seagrass meadows.
In the initial trial phase of the project, the team is in the process of deploying 2,000 sandbags back into the Shark Bay Heritage Area, with early results already visible.
“It’s exciting to see our sandbags already gathering seedlings and making progress in restoring the seagrass meadows,” said Liam Ridgley. “The enthusiasm from our volunteers and project partners has been incredible. Their support is a testament to the community’s commitment to protecting Shark Bay’s unique ecosystem.”
The trial will be used to evaluate different project variables and refine plans for a major expansion in 2025, where it’s planned for a further 10,000 bags to be deployed in 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.
If you would like to know more about the project or get involved become a member of OzFish online at www.ozfish.org.au or contact 1800 431 308.
