South Australia’s coastal waters have witnessed a remarkable transformation of a lost reef ecosystem off the shores of Glenelg.
In just a few short years, what was once a desolate expanse of sand has become a thriving marine haven teeming with life. This extraordinary accomplishment is a testament to the power of innovation and environmental stewardship.
The restoration was a joint effort and collaboration between the South Australian Government, NPOs and the University of Adelaide.
The construction of the reef was made possible by the Government and The Nature Conservancy. Once the reef was built (limestone boulders were put down) an environmental not-for-profit organisation called The Australian Ocean Laboratory (AusOcean) got involved to run a 5 month long experiment using underwater speakers to attract oysters to the reef.
At the helm of this project was Catherine Larkin, a Marine Ecologist and leader of science and operations at AusOcean. As an advocate for the improvement of ocean resources through technology, Larkin and her team have pioneered the development of low-cost, open-source ocean technology, with a particular focus on ocean data collection and communication.
The process was no easy feat, requiring careful planning and collaboration.
“Prior to European settlement, Australia’s coastline was adorned with vibrant oyster reefs, which provided vital habitats for marine life. However, destructive fishing practices brought by European settlers decimated these reefs, leaving behind a barren landscape. Our mission at AusOcean was to support restoration efforts by developing novel technologies that have the potential to accelerate reef regeneration,” Larkin explains.
Working alongside researchers from the University of Adelaide, led by Prof. Sean Connell and Dr. Dom McAfee, AusOcean implemented a unique strategy.
The first step involved the placement of thousands of tonnes of limestone boulders, which served as the initial substrate for reef regrowth. Then, utilising their low-cost speaker technology made from PVC pipe and commercial off-the-shelf electronics, the team played the sounds of a healthy reef system to attract baby oysters to settle on the newly restored reef.
“Although oysters don’t have ears, they possess the ability to sense and respond to their environmental surroundings through vibrations. By manipulating the soundscape, we can guide oyster larvae to optimal settlement sites, encouraging the formation of reef habitats,” Larkin explains.
“This complex habitat is critical for the resilience of marine systems and the long-term health of our coastal ecosystems.”
The Glenelg reef restoration project was initiated in the summer of 2020, where thousands of tonnes of limestone reef was deployed just 1 kilometer off the coast. Since then, the reef has undergone a spectacular metamorphosis. Once a barren expanse, it is now a thriving marine ecosystem, brimming with diverse and vibrant life forms.
The reef’s intricate structures provide refuge to delicate oysters and scallops, while sponges and ascidians create a stunning tapestry of colours on its surface. The gentle sway of red and green algae in the currents adds to the biodiversity of the reef, painting a mesmerising picture of nature’s resilience.
Looking ahead, Larkin emphasises the long-term sustainability of the restored reef, stating, “Now that the initial foundations have been established, the reef will continue to grow and evolve as oysters and other shellfish settle and contribute to the building of this complex three-dimensional habitat.”
Oyster reef restoration is important, as they act as unsung ecological superheroes, cementing together to create complex habitats that support a wide range of invertebrates.
These reefs enhance the density and diversity of smaller organisms, which in turn nourish the broader coastal food web. Furthermore, oysters are natural water filters, with a single oyster filtering up to 150 litres of water per day. The cumulative filtration capacity of an entire reef is an awe-inspiring feat, improving water quality and promoting the growth of neighbouring seagrass.
AusOcean’s success in helping revive the lost reef ecosystem off Glenelg stands as a testament to the transformative power of innovative approaches and collaborative efforts.
By harnessing technology and scientific expertise, they have not only helped restore a vital marine habitat but also provided a blueprint for future restoration projects. Their achievement serves as a shining example of how human intervention can heal and protect our precious oceans, ensuring a sustainable future for generations to come.
For more information about AusOcean, head here. You can also read about combining ecology and technology to kick-start oyster reef restoration here.
More News
