Community-led marine restoration project to address algae bloom

A reef restoration project led by University of Adelaide researchers is to be expanded across South Australia to learn how we can address the ongoing algal bloom, with new funding announced by the South Australian Government. 

The pilot restoration project at Coffin Bay in South Australia is set to be rolled out at 25 sites along the State’s coastlines.  

The University of Adelaide’s Dr Dominic McAfee, who is a Future Making Fellow from the Environment Institute and School of Biological Sciences, conducts research into restoring lost marine ecosystems, specifically shellfish reefs. 

“With the help of local school students and conservation volunteers our project has been able to restore native oysters by constructing shell reefs around Coffin Bay,” said Dr McAfee. 

“Native oysters are very important for the marine environment. Oysters are filter feeders that consume phytoplankton and other small algae suspended in the water, and this includes some types of algae blooms.” 

The SA Government has announced a project to support community-led reef restorations on Kangaroo Island and at sites across the Eyre and Yorke Peninsula over the next three years. 

"In South Australia, native oyster communities have been brought back within three years of reefs being constructed, after more than a century of functional extinction,” said Dr McAfee. 

“Oysters open their shells and draw water across their gills, filtering out microscopic algae and other particles for food. 

“The current algal blooms has been lethal to many filtering bivalves, but the native oysters appear to have a level of resilience to the bloom.” 

The algal bloom in South Australia was first noticed in mid-March this year when surfers and beachgoers on the Fleurieu Peninsula reported falling ill after exposure to seawater. The bloom was later identified as being caused by various species of  Karenia algae, among other harmful algal species.  

“Harmful algal blooms (HABs) can produce toxins that can accumulate in shellfish, including oysters. The oysters can purge the toxins once the algae reduces, and the oyster industry monitors farmed oysters closely to ensure they are safe to sell,” said Dr McAfee. 

“The native oysters that would grow on the new reef restorations are being restored for their ecological benefits like water filtration. They are not to be harvested for food.” 

In recognition of its on-the-ground impact, Dr McAfee and conservation group EyreLab were recently awarded a $20,000 grant from the Australian Geographic Society to support his project.