YP’s Windara Reef is at the forefront of providing new “blue economy” jobs and boosting ecotourism through marine habitat restoration.
Construction of Australia’s biggest reef restoration project, south of Ardrossan in Gulf St Vincent, has now been complete. The second phase has added an additional 11,000 square metres of reef over a further 16 hectares. More than seven million juvenile Australian Flat Oysters have now been laid on top of the reef base.
The reef will enhance YP’s reputation as a great place for recreational fishing, boosting tourism and creating more local jobs. Read the full release here.
Whilst recreational fishers can continue to enjoy the reef, a reminder that commercial fishing, anchoring, spearfishing, taking of bottom dwelling organisms (shellfish including crabs, oysters, sea urchins, seaweed, etc) are not allowed on the reef.
YPC partnered with The Nature Conservancy, SA and Federal Govt, RecFishSA and UofA to build Stage I of the reef in 2017. (Photos by The Nature Conservancy).
Stage II Construction
Construction of YP’s 20 hectare Windara Reef near Ardrossan is now complete. The Reef is already attracting new fish colonies and is expected to host millions of native oysters. Media courtesy of The Lead.
Giant man-made reef ready to revive Australia’s native oyster
The final construction stage of the largest man-made oyster reef system outside the United States has been completed in South Australia.
The 20-hectare (50 acre) reef in the waters of Gulf St Vincent in South Australia is the first of what is hoped to be five major reef projects in the state to revive wild populations of the almost extinct Ostrea angasi native mud oyster.
The 4ha Stage 1 of the project was completed in June 2017 and 30,000 adult native oysters were embedded across the 15 limestone structures in January this year.
Work on Stage 2 began in late August and was completed [in September 2018]. It involved placing almost 10,000 tonnes of limestone boulders, each about the size of a soccer ball, to form 144 reefs across the remaining 16ha area.
The final part of the project included seeding the Stage 2 section with seven million one-month-old native oyster spat in November.
The project, about 1km off the coast of Ardrossan on South Australia’s Yorke Peninsula, aims to increase fish stocks for recreational anglers, improve water quality and biodiversity and revive the oyster in the Gulf.
The South Australian Department of Primary Industries and Regions (PIRSA) delivered the first 4ha of reef last year while the remainder of the project is the result of collaboration between the Australian Government, The Nature Conservancy, Yorke Peninsula Council, the University of Adelaide and the South Australian Department for Environment and Water.
Oyster reefs are considered the temperate water equivalent to coral reefs in tropical waters. Australia’s southern coastline was home to thousands of kilometres of oyster reefs before European settlement but dredging to remove substrate for lime production and the harvesting of oysters for food wiped out all the reefs except for one off the coast of Tasmania.
The Nature Conservancy (TNC) has been involved in dozens of shellfish reef restoration projects, chiefly in the United States and is considered a global expert on their establishment.
TNC Project Manager Anita Nedosyko said the first dives to measure the environmental benefits on water quality, fish production and biodiversity of stage one were conducted in May and June as part of a six-year study into the success of the project. She said while the reef system was dominated by turfing algae, the adult oysters placed on the reef were surviving and a number of wild oyster spat had also found its way to the reef, which was an unexpected bonus.
“You always get some opportunistic species and those will often be the first colonisers but then as that turfing algae is eaten by abalone or other shellfish then that will create space for other competing organisms,” Nedosyko said. “We’ve already seen abalone, scallops, sea urchins, schools of leatherjackets, snapper, magpie perch and a cuttlefish.
“Before we put any rock out we did a biodiversity survey and certain fish like the magpie perch, which is a rocky reef species, we didn’t see before and now we’re starting to see in the area and that’s the sort of shift that we’ll see as time goes on.”
The seven million one-month-old native oyster larvae will be attached at a hatchery near Port Lincoln to 12 tonnes of oyster shells that will be used to host the spat so it can be easily seeded onto the reef, which is in 8-10 metres of water.
The 144 limestone boulder reefs in Stage 2 are roughly 4m wide and 700mm high with lengths varying from 10m to 35m and are distributed evenly across the remaining 16ha area to form one large reef system.
Nedosyko said the individual reef clumps were designed to be close enough together so that native oyster larvae could move across the reef system through tidal flow.
“A successful reef for us will be one where oysters are surviving, spawning and producing new recruits and we’re also starting to see some additional biodiversity.”
Adult native oysters can filter more than 100 litres of water a day and excrete a mucus-like substance that is rich in nutrients and provides food for small shellfish that in turn provide food for larger fish.
Nedosyko said the ability to provide to clean water and provide a food source for small organisms gave native oyster reefs the ability to drive greater fish production than artificial reefs alone.
She said it was hoped the Windara Reef would eventually lead to increased fish production of 5 tonnes per hectare a year including recreational fishing favourites such as snapper and King George whiting. “It’s like a well-stocked fridge – it’s really attractive to fish coming in because they can stop, get fed and move on or decide to be residents. This is definitely an important site for us to be able to test the success of the ecological progression of the reef and also to test and trial the construction and deployment methods,” Nedosyko said. “We’re confident that by building native oyster reefs we’re going to achieve oyster survival but also greater biodiversity and therefore higher fish numbers at these sites.”
The first of its kind in South Australia and the largest in Australia, Windara Reef is a shellfish restoration reef in Gulf St Vincent. Windara Reef offers great fishing for recreational fishers with fish species including King George Whiting & Snapper.
The reef is named Windara Reef after the Narungga name for the eastern section of Yorke Peninsula, which is one of the 4 clans making up Narungga. It is located 1km off the Rogues Point coast, 7km south of Ardrossan and is at a water depth of 8-10 metres.
(Story by Andrew Spence, The Lead, 09/10/2018)
The 4-hectare site is the first construction phase of Windara Reef and is made of 60 custom-made concrete structures and over 800 tones of Yorke Peninsula limestone, covered with Pacific Oyster shells & juvenile native oysters. 12 months after Stage I’s construction, a video of the reef can be viewed here. The Windara Reef was seeded with 28,000 juvenile native oysters in January 2018 which will further assist in restoring Gulf St Vincent’s marine habitat. Stage II of the reef is scheduled to commence in early July 2018 with a further 16 hectares constructed.