Millions of people visit the Twelve Apostles every year, but it is the diversity of marine life under the Great Ocean Road icon that has scientists most excited.
Six months of underwater biological survey work has revealed the oceans off Victoria’s south-west coast are teeming with marine life including thriving reefs, rare sharks and a high density of fish and other underwater creatures.
A team of researchers from Parks Victoria, Deakin University and Museum Victoria surveyed 20 kilometres of coast from the Twelve Apostles Marine National Park to the Arches Marine Sanctuary.
Knowledge of the underwater world in the two marine parks had been limited until now because of the region’s wild ocean conditions. But recent improvements in underwater cameras allowed the researchers to unlock the area’s secrets.
Museum Victoria’s head of science, Dr Mark Norman, said the survey had found the health of the marine life in the two parks was in really good condition.
“We were really pleased by not seeing introduced pests and seaweed species which can be a problem in other regions,” Dr Norman said.
He said through the surveys the group had managed to capture some of the only footage in existence of rare shark species in their natural habitat.
Shark species recorded in the parks included shy threshers, prehistoric sevengills, and the Port Jackson shark. All up nine shark species were recorded.
Dr Norman said the healthy density of fish and other marine species showed the parks were playing the protection role that was intended when they were declared. He said the parks also gave researchers a healthy environment to compare with more impacted oceans.
In areas too deep to dive, the researchers dropped baited video cameras into the ocean, which along with sharks, recorded large numbers of snapper, leatherjackets, squid and giant stingrays.
Sonar technology was also used to map the area’s seabed in high detail, which will be matched with the camera and dive data to determine the relationship between fish and habitat.
Parks Victoria ranger project co-ordinator for Port Campbell, Natasha Johnson, said the reef’s under the Twelve Apostles also included a huge diversity of invertebrates such as moss animals known as bryozoans, sac-like ascidians and sponges.
“The reef is just basically covered in invertebrates. Every section where something can grow it grows. The marine life down there is just thriving, it is really good to see,” she said.
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