Deakin University has joined The Nature Conservancy (TNC), the University of Melbourne and Parks Victoria to announce a plan to trial and develop techniques to address the loss of Golden Kelp in Port Phillip Bay.
Bringing together Victoria’s leading organisations working with kelp and urchin research, management and restoration, this project will support the recovery of kelp forest habitats in Victoria.
Kelp forests support a wide range of marine animals and plants, many of which are unique to southern Australia. Kelp forests are also responsible for supporting Australia’s high value abalone and crayfish fisheries, coastal tourism and recreational industries.
With funding from the Victorian Government’s Department of Energy, Environment and Climate Action, the Port Phillip Bay Golden Kelp restoration project will include the first trials in Victoria to cultivate Golden Kelp at the microscopic level for planting onto reefs.
“This involves growing microscopic kelp in the laboratory at the Queenscliff Marine Science Centre,” said Dr Prue Francis, a Senior Lecturer in Marine Science at Deakin University and co-leader of the kelp cultivation program.
“Juvenile kelps will be grown on twine or gravel and planted out onto targeted areas, ready to mature. These trials will research and develop the best methods for Golden Kelp cultivation and restoration in Port Phillip Bay to guide future restoration efforts at a larger scale,” Dr Francis said.
Scott Breschkin, TNC’s Oceans Project Coordinator for Victoria, said that kelp forests in Port Phillip Bay have undergone significant decline in the last two decades, predominantly because of the increased abundance and overgrazing by native Purple Urchins, Heliocidaris erythrogramma.
This has led to kelp forest and macroalgae habitats being replaced by urchin barrens, which appear as areas of bare rock, devoid of much marine life except a high abundance of urchins.
“With 60 per cent of all rocky reefs in Port Phillip Bay impacted by overgrazing of urchins and substantial declines of kelp forest and macroalgae habitats in northern Port Phillip Bay, we’re trialling how best to recover this important ecosystem,” Mr Breschkin said. “Without intervention, further loss of kelp forest habitat will likely continue in the bay.”
The project will focus on restoration of Golden Kelp forests on rocky reefs within and outside of marine protected areas and will also involve the management of overabundant herbivore urchin populations.
“Over the two-year project, in situ culling of urchins will be conducted within at least four hectares across Jawbone Marine Sanctuary in Williamstown and Ricketts Point Marine Sanctuary in Beaumaris to allow for passive and active recovery of kelp forest and macroalgae habitats,” said Dr Michael Sams, the manager of the marine and coastal science program at Parks Victoria, who is leading the urchin management program in partnership with the University of Melbourne. “Culling is the best practical action to reduce urchin numbers and is a proven first step to facilitate recovery.”
Once urchin numbers have been reduced to within healthy limits to promote the recovery of kelp and other macroalgae (~2 urchins/m2), the project will trial planting juvenile kelp on twine and gravel to restore Golden Kelp in up to one hectare, primarily across Jawbone and Ricketts Point marine sanctuaries, where widespread loss of kelp forest habitats have occurred.
“Close monitoring will allow us to assess the success of urchin culling and kelp restoration activities to inform future restoration and urchin management efforts,” said Professor Stephen Swearer, Director of the National Centre for Coasts and Climate at the University of Melbourne, who is leading the monitoring program.
“The Port Phillip Bay Golden Kelp restoration project is expected to benefit all Victorians and current and future visitors, by contributing to the recovery of one of Victoria’s most important marine ecosystems and supporting marine biodiversity in Port Phillip Bay,” Mr Breschkin said.