Massive Restored Reef Aims to bring South Ӱֱ’s Oysters Back
Researchers from theӰֱ of Adelaide have undertaken thelargest oyster reef restoration project outside the United States in the coastal waters of Gulf St Vincent, near Ardrossan in South Ӱֱ. Construction began earlier this month with some 18,000 tonnes of limestone and 7 million baby oysters set to provide the initial foundations for a 20-hectare reef.
The project is worthA$4.2-million and will be built in two phase. It will be completed by December 2018, with the first phase of the 4-hectare trial currently being built by; the second phase will see the reef expand to 20 hectares, led byThe Nature Conservancy.
200 years ago the native mud oyster,Ostrea angasi, formed extensive reefs in the Gulf, along more than 1,500km of South Ӱֱ’s coastline. Today there are no substantial accumulations of mud oysters anywhere around mainland Ӱֱ, with justone healthy reef remaining in Tasmania.
This restoration project aims to pull our native mud oyster back from the brink of extinction in the wild, and restore a forgotten ecosystem that once teemed with marine life.
Oysters played a large role in Ӱֱ’s colonial history. When European settlers first arrived they had to navigate a patchwork of oyster reefs (also calledshellfish reefs) that filled the shallow waters of the temperate bays. These enormous Ӱֱ could cover 10 hectares in a single patch, providing an easily exploited food resource for the struggling early settlers. Oyster shell was burned to produce lime, and the colony’s first buildings were built with the help of oyster cement.
Collectively, pre-colonial oyster reefs rivalled the geographic extent of the Great Barrier Reef, covering thousands of kilometres of Ӱֱ’s eastern and southern coastlines. For thousands of years oyster reefs fed and fuelled trade among Aboriginal communities. Shell middensdating back 2,000 yearsattest to the cultural importance of oysters for coastal communities, who ate them in abundance and used their shells to fashion fishhooks and cutting tools.
The appetite of the newly settled Europeans devastated live oysters for food and dead shell foundations were scraped from the seabed for lime burning, which was critical for the settlement of new oysters. The combination of lost hard shell bed and increased sediment runoff from the rapidly altered coastal landscape, saw oyster populations crash within a century of colonisation.
Today, oyster populations are atless than 1% of their pre-colonial extentin Ӱֱ. Globally it is estimated that85% of oyster habitat has been lostin the past few centuries, making it one of the most exploited marine habitats in the world.
A solitary oyster canfilter about 100 litres of water a day, which means thaten massethey can function as the “kidneys” of ocean bays, filtering excess nutrients from the water and depositing them on the seafloor. In doing so, they encourage seagrass growth, while their physical Ӱֱ help todissipate wave energyand thus reduce the impact of storm surges.
As a carbon sink, oysters build calcium carbonate shells that are buried in the seafloor after death and eventually compacted to rock, thus helping to prevent carbon dioxide from cycling back into the atmosphere.
Restoring oyster reefs has the potential to return these ecosystem services and increase the productivity of coastal ecosystems. The Gulf of St Vincent project is a collaborative partnership between the , ,, whilst the Ӱֱ of Adelaide is working to ensure that the restored oysters survive and thrive, and that the reef continues to grow.
Original story from
How has it been done? Watch the video
Adelaide Ӱֱ Researchers - @ and
The project is worthA$4.2-million and will be built in two phase. It will be completed by December 2018, with the first phase of the 4-hectare trial currently being built by; the second phase will see the reef expand to 20 hectares, led byThe Nature Conservancy.
200 years ago the native mud oyster,Ostrea angasi, formed extensive reefs in the Gulf, along more than 1,500km of South Ӱֱ’s coastline. Today there are no substantial accumulations of mud oysters anywhere around mainland Ӱֱ, with justone healthy reef remaining in Tasmania.
This restoration project aims to pull our native mud oyster back from the brink of extinction in the wild, and restore a forgotten ecosystem that once teemed with marine life.
Oysters played a large role in Ӱֱ’s colonial history. When European settlers first arrived they had to navigate a patchwork of oyster reefs (also calledshellfish reefs) that filled the shallow waters of the temperate bays. These enormous Ӱֱ could cover 10 hectares in a single patch, providing an easily exploited food resource for the struggling early settlers. Oyster shell was burned to produce lime, and the colony’s first buildings were built with the help of oyster cement.
Collectively, pre-colonial oyster reefs rivalled the geographic extent of the Great Barrier Reef, covering thousands of kilometres of Ӱֱ’s eastern and southern coastlines. For thousands of years oyster reefs fed and fuelled trade among Aboriginal communities. Shell middensdating back 2,000 yearsattest to the cultural importance of oysters for coastal communities, who ate them in abundance and used their shells to fashion fishhooks and cutting tools.
The appetite of the newly settled Europeans devastated live oysters for food and dead shell foundations were scraped from the seabed for lime burning, which was critical for the settlement of new oysters. The combination of lost hard shell bed and increased sediment runoff from the rapidly altered coastal landscape, saw oyster populations crash within a century of colonisation.
Today, oyster populations are atless than 1% of their pre-colonial extentin Ӱֱ. Globally it is estimated that85% of oyster habitat has been lostin the past few centuries, making it one of the most exploited marine habitats in the world.
A solitary oyster canfilter about 100 litres of water a day, which means thaten massethey can function as the “kidneys” of ocean bays, filtering excess nutrients from the water and depositing them on the seafloor. In doing so, they encourage seagrass growth, while their physical Ӱֱ help todissipate wave energyand thus reduce the impact of storm surges.
As a carbon sink, oysters build calcium carbonate shells that are buried in the seafloor after death and eventually compacted to rock, thus helping to prevent carbon dioxide from cycling back into the atmosphere.
Restoring oyster reefs has the potential to return these ecosystem services and increase the productivity of coastal ecosystems. The Gulf of St Vincent project is a collaborative partnership between the , ,, whilst the Ӱֱ of Adelaide is working to ensure that the restored oysters survive and thrive, and that the reef continues to grow.
Original story from
How has it been done? Watch the video
Adelaide Ӱֱ Researchers - @ and
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