RESEARCHERS working in one of Australia's marine reserves off the mid north coast of NSW have inadvertently captured an immense 'fever' of Australian cownose rays on film.
This extraordinary sight is seldom witnessed and rarely caught on film.
Southern Cross University marine biologist Associate Professor Brendan Kelaher was using a standard piece of surveying equipment known as a baited remote underwater video, or BRUV, to record species' diversity and abundance at Pimpernel Rock in the Solitary Islands Commonwealth Marine Reserve.
At first sight the video shows snapper, mado and yellowtail scad swimming around the BRUV before a sweep of rays moves into the background. Dozens of rays quickly turn into more than 100 as they fly through the water like a giant flock of underwater birds.
Associate Professor Kelaher, who is based at the University's National Marine Science Centre in Coffs Harbour, said little was known about this species and while he knew about huge fevers of rays it was the first time he'd ever seen anything like it.
"When we conduct these surveys we are fortunate to see the incredible diversity of marine life in our protected marine habitats," he said.
At Pimpernel Rock we are privileged to see critically endangered fish and dive with these marine animals. But to see a large fever of cow-nose rays is amazing, especially towards the southern limit of their distribution.
"It really shows the richness and abundance of life in Australian waters."
The Pimpernel Rock Sanctuary Zone is seven kilometres off the coast of Sandon Bluffs, NSW, inside the Solitary Islands Commonwealth Marine Reserve. BRUV surveys have been undertaken at Pimpernel Rock for several years to better understand the type and number of species that inhabit the reserve and to provide a basis for effective management of reserves.
Parks Australia's Jason Mundy oversees the management of Australia's marine reserve network.
"The video monitoring of our reserves showcase an astonishing amount of marine life," Mr Mundy said.
"This is the first time I've ever seen footage like this off the coast of NSW. You see the first few rays in the background flying into view and then they just keep on coming."
Pimpernel Rock is widely regarded as one of the finest scuba diving locations along the entire New South Wales coast and is home to the critically endangered grey nurse shark.