South Australia’s Glenelg shellfish reef doubles in size

South Australia’s first project under the Reef Builder program is now complete in Glenelg.  

The existing shellfish reef off the coast of Glenelg has been expanded from 2 ha to 5 ha, providing a boost for local marine environments as well as new jobs, tourism and recreational opportunities. 

The Nature Conservancy Australia (TNC) led the expansion work, in partnership with the Australian Government and the South Australian Government’s Department for Environment and Water.

TNC Australia’s Oceans Coordinator Anita Nedosyko said that the shellfish reef was constructed using a limestone reef base, sourced from a local quarry. The base will soon be seeded with hatchery-raised Australian Flat Oyster spat to re-create a living shellfish reef over the next few years.

“This is a promising sign for shellfish reef recovery in South Australia and we're thrilled to expand the reef to this scale at a site that is easily accessible to scuba divers,” Ms Nedosyko said. “Oysters are excellent water filters, with one oyster filtering up to 100 litres of water a day. This helps improve local water conditions and support the return of other ecosystems like seagrass.”

Minister for the Environment Sussan Ley said the project is part of the Australian Government’s $20 million commitment to rebuild 13 native shellfish reefs and the first of three reefs in South Australia. 

“Shellfish reefs once thrived around Australia’s coasts but were victim to overharvesting and dredging in the late 1800s,” Minister Ley said.

“Our $20 million Reef Builder Program through The Nature Conservancy is helping to reverse some of that damage with each reef capable of boosting fish stocks by thousands of kilograms each year.”

South Australian Minister for the Environment and Water David Speirs said the existing reef at Glenelg was now larger than two Adelaide Ovals. 

“Shellfish reefs provide significant environmental benefits like habitat for fish and improved water quality, but they also provide new recreational and economic opportunities,” Minister Speirs said. 

“We want to bring people closer to our wonderful natural environment, particularly after the impacts of COVID-19 and we want to help them be a part of protecting and preserving our environment for generations to come.” 

Completed a year ago by TNC with the support of the SA Department for Water and Environment and local philanthropists, the first restored shellfish reef at Glenelg has already shown fantastic early results. Ms Nedosyko said thousands of oysters had already established on and around the reef, largely exceeding expectations.

"Some of the oysters growing here are already the size of the palm of your hand. Glenelg has excellent conditions for shellfish reef restoration which is why it makes sense to invest in expanding this reef,” Ms Nedosyko said.

“These shellfish reefs provide homes for many marine species - thereby boosting biodiversity and fish stocks. We have seen schools of Cowfish, Leatherjackets, Southern Goatfish, Blue Swimmer Crabs and squid make a home on the reef.”

Glenelg is one of 13 sites identified for reef restoration under the Australian Government’s $20 million investment in Reef Builder. A partnership between the Australian Government and TNC Australia, Reef Builder aims to bring shellfish reefs back from the brink of extinction and support the economic recovery of communities impacted by bushfires and COVID-19 restrictions. 

All projects under Reef Builder are part of TNC Australia's National Reef Building Project that aims to rebuild 60 reefs alongside communities who need them most. If achieved, it will make Australia the world’s first nation to recover a critically endangered marine ecosystem.