Pursuit of a predator

Leighton De Barros filming the expedition vessel arriving back in port in Esperance.
Leighton De Barros filming the expedition vessel arriving back in port in Esperance.

The documentary, Search for the Ocean’s Greatest Predator, which airs on ABC1 on Sunday at 7.30pm, investigates how a three-metre great white shark, fitted with an electronic tracking tag in 2003, was suddenly eaten by an unknown predator.

Two weeks later, the tracking tag, believed to have been carried in the stomach of the predator, washed ashore, leading the shark’s tagger and wildlife cameraman David Riggs, from Esperance, on a 10-year search to find the identity of the predator.

During his search, Mr Riggs discovered an unknown deep-water food source in the Bremer Canyon, near Bremer Bay, in Australia’s Southern Ocean, where killer whales, giant squid and great white sharks feed for about two months each year.

Mr De Barros (pictured) spent three weeks at sea on a boat fitted with specialised camera equipment with Mr Riggs and some of the country’s leading scientists to help capture foot-age for the documentary, which attempts to answer questions surrounding the Bremer Canyon’s mysterious ecosystem.

‘I think what attracted us to Dave’s story is that it’s an interesting story about coincidence ” the shark being tagged and then getting eaten by something else and whatever it was regurgitated the tag back up, which came back to almost exactly where the shark was tagged,’ he said.

‘It’s a one in a million chance to get that tag back and all the data,’ Mr De Barros said.

‘It takes people on a journey to understand what could attack a shark like this.’

Mr De Barros said the documentary, which identifies Australia’s first residential killer whale pod and giant squid, wasn’t without its challenges.

‘Anything involving boats and is a long way offshore is a nightmare. The logistics of working on the Southern Ocean are very hard.’

While battling the conditions in an attempt to capture footage of the shark’s predators, Mr Riggs and the scientists tried to find out more about the Bremer Canyon phenomenon, which is attracting the abundance of marine life.

‘Dave became obsessed with finding out what had killed the shark. The whole story led him to the Bremer Canyon and this big profusion of life, which he found out was going to be mined for oil and gas.

‘Ultimately he wants to find out what is down there and protect it.’
Having worked on many films broadcast by Discovery Channel, Animal Planet and National Geographic,

Mr De Barros said the aim of any wildlife documentary was to create awareness and educate people about the environment.

Mr Riggs said now the aggregation of marine life at the Bremer Canyon has been uncovered, he hopes to find further funding for a citizen science project, which will allow members of the public to go out on the boat with scientists and assist with research.

‘What we need to know is if there is a link between this hydrocarbon system down in the Bremer Canyon and what we are seeing on the surface.

‘A few years back I participated in an expedition to the Antarctic. What we have off the coast of Bremer Bay rivals anything I saw down there.’

Visit www.riggsaustralia.com.