It saw service in the Gulf War and East Timor and helped in the rescue of round-the-world solo yachtsmen Tony Bullimore and Thierry Dubois from the Southern Ocean. Sunk off the NSW Central Coast in 2011, ex-HMAS Adelaide today teems with marine life and has become a hugely popular scuba diving site.
Divers used to describe the seabed where the ship was scuttled as a virtual marine desert. Thanks to the ship, the area is now home to schools of Kingfish, Mulloway, Yellowtail, Sweep and cuttlefish, among others, and the ship is covered in algae, sponges, barnacles and tube worms.
It’s been a boost for local tourism, says Terrigal Dive Centre owner, Les Graham, with thousands of divers visiting the site every year to swim through the ship which retained its steering gear, wheelhouse, toilets and sinks.
“I reckon what you are seeing there now on the wreck is like what you might have seen about 150 years ago before we began fishing in the area,” says Graham.
“We have seen some fish move onto the ship that we didn’t expect to see at all,” says Professor Gladstone, who is supervising UTS research student Guy Graham’s investigation of the effects of the ship on fish that live on nearby natural reefs.
Professor Gladstone says many species of fish spend their adult life permanently occupying small territories on a reef so it was a surprise to see them arrive at the ship as adults.
“That means they would have swam across 400 metres of open sand, with nowhere to hide from predators, to get to the ship from the nearest reef,” he says.
“Guy’s research is trying to determine if scuttling a big ship like the HMAS Adelaide in an area surrounded by natural reefs would affect those reefs. We are also interested in how the environment of the scuttled ship changes over time and whether it will ever resemble a natural reef.
“There has been a definite change in the fish life. The ship was first colonised by schooling Yellowtail, followed by Sweep and Kingfish over several months. Although not actually living on or within the ship these species of fish encircle the ship in large schools. After several more months the ship had been colonized by fish that live on and within it, such as wrasse and damselfishes.
“Our research is suggesting that, even though some fish appear to have migrated to the ship from nearby reefs, the numbers have been so small that for most species there has been no noticeable change to their populations on these reefs.”
This story written and produced by the University of Technology, Sydney, for Brink, a publication distributed monthly in The Sydney Morning Herald.
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