4 things you might not know about South Australia’s new shellfish reef

Have you heard about the new shellfish reef being built off Ardrossan’s coast?

When it’s established, it will improve the habitat for fish and will help attract fish species that are popular with anglers.

In the longer-term, the reef will act as a breeding ground for these and other fish.

While the first reef segments were laid a couple of years ago, there’s recently been some exciting updates to this project, including these four things you might know about:

1. Oysters have been introduced to restore the marine reef ecosystem

In the latest stage of the project, more than 50,000 native oysters were introduced to the restored reef in late-April as part of what has become Australia’s biggest reef restoration project – led by The Nature Conservancy.

This was the first of two oyster deployments for 2019, which together will seed the new reefs with more than 7 million juvenile Australian flat oysters (Ostrea angasi) grown in our very own South Australian hatcheries.

The oysters, which were about eight months old at the time of seeding, are roughly the size of a 50- cent piece.

Oysters can filter up to 100 litres of water each per day, while the reefs provide a nursery area for young fish, and their empty shells are used by some species of fish to lay their eggs.

The now at-home baby oysters will start producing spat (offspring) when they are about three years old, which will help create a self-sustaining reef.

Keen to see how it happened? Watch this video:

2. Windara Reef is the first shellfish restoration reef of its kind in SA

While the reef in north-western Gulf St Vincent will take about seven years to fully establish, it will hopefully mean more species of fish will make their home in the reef habitat – which means a better chance of hooking a decent haul.

‘Windara’ is the Narungga name that was chosen for the reef in recognition of the local Aboriginal peoples’ connection with sea country and refers to the eastern area of the Yorke Peninsula region where the reef is located.

3. Right now, there are no known native oyster reefs left in SA

Shellfish reefs dominated by Australian flat oysters were common in SA gulfs and bays in the 1800s. In fact, researchers estimate that they once spread across 1500 kilometres of coastline.

Today, no native oyster reefs remain – mainly because of the impact of overfishing, dredging, water pollution and disease.

4. The reef is getting bigger and better

Construction of Windara Reef began in 2017 with 150 limestone reef segments laid across the bare, sandy seafloor area just off the coast of Ardrossan on the Yorke Peninsula.

The reef itself is now being expanded to 20 hectares, and the seeding of these oysters is an important step in the process.

Once fully established, the reef will boost fish productivity and improve water quality in the region.

This project is a partnership funded by The Nature Conservancy, the Australian Government, the South Australian Government, the Yorke Peninsula Council, The University of Adelaide and the Ian Potter Foundation. The oysters were donated by Primary Industries and Regions SA’s research division, SARDI (the South Australian Research and Development Institute).

Interested in science? You might like to learn about how baited remote underwater video systems are helping scientists measure marine life abundance.

Main image: oysters being introduced to the reef (image courtesy of The Nature Conservancy)