From the lab to the Bay

Another exciting milestone is underway for the Golden Kelp Restoration Project in Port Phillip Bay.

After successful trials last year, when over 50,000 baby kelp were outplanted onto rocky reefs, The Nature Conservancy Australia (TNC) and its partners, Deakin University, the University of Melbourne and Parks Victoria, are excited to add another few hundred thousand baby kelp to the Ricketts Point and Jawbone Marine Sanctuaries in Port Phillip Bay, Victoria.

For the next couple of weeks, baby kelp, grown from microscopic spores on spools of twine and on small rocks at the Deakin University Queenscliff Marine Science Centre, will be outplanted by TNC divers and attached to rocky reefs where they are expected to keep growing and support the recovery of Golden Kelp forests.

Scott Breschkin, TNC’s Seascapes Conservation Officer for Victoria, said that this was an important step in the restoration process.

“The first successful outplanting trials, conducted in July and December 2023, enabled us to pilot different techniques for growing and planting out kelp onto the reef.

“With many of the Golden Kelp forests now struggling to recover by themselves, we are delighted that the initial outplanting trials have shown signs of success. This means we have the information and techniques needed to start scaling up restoration efforts,” he said.

Golden Kelp forests in Port Phillip Bay have undergone significant decline in the last few decades, due to a combination of factors but primarily due to the increased abundance and overgrazing by native Purple Urchins (Heliocidaris erythrogramma).

 “Urchin barrens, which look like widespread areas of bare rock devoid of the abundance of life typically found in kelp forests, have replaced kelp forests and other macroalgae habitats in much of Port Phillip Bay,” Mr Breschkin said. “However, kelp forests are a really important ecosystem and form the backbone of the Great Southern Reef which extends along 8,000km of coastline from NSW to WA: they provide habitat, feeding and nursery grounds to countless species of fish, crustaceans, shellfish and other algae, many of which are unique to southern Australia, with over 70% of these species not found anywhere else in the world.”

Over the past year, researchers at Deakin University have developed techniques to grow local kelp in the laboratory, starting with microscopic spores from healthy adult kelp. Dr Jacqui Pocklington says, “our Technical Officer, Jasmine Bursic has spent around a year growing and bulking the kelp cultures to enable this upscale of planting to be possible”.

The baby kelp have been nurtured in specialised aquaria for about eight weeks before being ready to be out planted into the Bay. Deakin’s Dr Jacqui Pocklington says “by tweaking factors like temperature, light, and how much kelp we grow on the twine and rocks, our team has managed to grow over twice as much kelp compared to previous attempts. The kelp is looking better than ever, and we’re excited to get them into the Bay”.

This work is part of a project funded by the Victorian Government’s Department of Energy, Environment and Climate Action to trial and develop techniques to address the loss of Golden Kelp and other native macroalgae that form seaweed forest habitats in Port Phillip Bay.