Underwater footage captured of shark feeding frenzy
MARINE scientists in French Polynesia have captured high-resolution underwater footage of a swarm of sharks feasting on schools of tropical fish.
The scientists and their camera crew were perfectly positioned to witness tens of grey reef sharks ferociously attacking a school of spawning marbled grouper.
Once a year up to 10,000 of the fish gather in a narrow channel to mate - and attract hundreds of sharks that hunt the grouper while they are distracted and exposed.
The footage wasn't just an awesome sight to behold - it also contained startling new discoveries about shark behaviour.
One of those was that sharks are intensely competitive between each other, and can be seen fending off their catch from other rivals in a visceral tug of war, often ripping their large prey to pieces in the process.
No wonder sharks are such top-line predators - they have to work hard for their meal. During their "feeding frenzy" they caught as little as one in 20 of the fish they targeted, making it hungry work.
The cinematographers also captured shark feeding behaviours never seen before, including sharks pulling prey off the coral reef in broad daylight.
"Grey reef sharks are an adaptable predators," said Dr William Robbins of Wildlife Marine and lead author of the study,
"This research shows sharks modify their hunting strategy based on the type of fish they are targeting-slow and steady for agile fish like fusilier, fast and furious for large fish like grouper."
The scientists are part of the Global Reef Expedition - circumnavigating the globe studying the health of remote coral reefs - working under the Khaled bin Sultan Living Oceans Foundation, and were joined by a film crew shooting footage for a US documentary called Mysteries of the Coral Canyon.
Their research, published in the journal Coral Reefs, is the first to document natural predatory behaviour of grey reef sharks.