Results from the latest monitoring of the restored shellfish reefs in the Swan-Canning Estuary show underwater life is thriving, with the reefs significantly boosting the health and biodiversity of the iconic waterway.
Tony Jupp, Director of Conservation for The Nature Conservancy Australia said, "This landmark project is the largest of its kind in WA, and involved constructing 24 individual shellfish reefs in the lower Swan-Canning Estuary, at 4 locations. These reefs have been in place for about 18 months now, and the latest monitoring results from mid-year highlight significant biodiversity improvements at our local reef sites compared to the bare sediments they were previously, marking a major success in the project."
"We are seeing very promising signs and increased marine life, including Leatherjackets, resident Tarwhine, Pink Snapper, Western Striped Grunter and Western Gobbleguts. We're also seeing natural settlement of a range of shellfish species onto the reefs, including scallops and oysters."
WA Oceans Manager Brett Dal Pozzo added, "We use the Reef Life Survey method for monitoring, which is a visual census carried out by scientific divers. This allows an accurate count of fish and other mobile, cryptic or sessile marine life, and provides an excellent snapshot of how the reefs are developing. What we've seen here is that the reefs are developing well - even better than projected in many ways - and are teeming with life. What we learn from monitoring also directly informs our approach for future restorations across Western Australia and the rest of the country, as we get closer to achieving our target of restoring 60 shellfish reefs nationally by 2030."
It is expected that over time, the reefs will continue to mature and provide rich habitat for a range of marine and estuarine species.
The positive outcomes of this project underscore the importance of native shellfish reefs, Australia's most threatened marine ecosystem, as critical to increased marine biodiversity - but more work is still to be done. Next steps include reef enhancement trials which will see treatments to bolster natural shellfish recruitment; exploring the potential for seeding existing reefs with more Australian Flat Oysters or other shellfish species; ongoing reef monitoring to guide future management; the continuation of Ozfish citizen science fish monitoring program and a final Reef Life Survey in May next year. A reef management and monitoring plan will be developed, with DBCA, for for beyond July 2025.
Delivering this project has been the result of a tremendous collaboration across government, industry, academia, Derbarl Yerrigan Knowledge Holders and the broader community, with generous funding support provided by Lotterywest, the Minderoo Foundation, Western Australia's Department of Biodiversity, Conservation and Attractions (DBCA), the Australian Government's Reef Builder initiative, as well as Jock Clough, Adrian & Michela Fini, Austral Fisheries, Gavin Bunning, Major Holdings Pty Ltd, the Ungar Family and Michael & Margrete Chaney.
