Researchers get closer to Sharks with REMUS SharkCam

 

Dramatic footage of great white sharks attacking an underwater camera has recently gone viral across the internet. Filmed in 2013, the videos give a glimpse into the underwater  hunting techniques employed by great white sharks. Much of the previous footage of great white attacks centred around the spectacular breaching of the sharks as they tackle sea lions near the surface, this new footage gives us a closer view than ever of how this magnificent creatures stalk and hunt their prey.

The REMUS AUV (autonomous underwater  vehicle) has allowed researchers to successfully track and image sharks autonomously in what is a first for a marine species. “We wanted to test the REMUS SharkCam technology to prove that is was a viable tool for observing marine animals, sharks in this case, and to collect substantial data about the animals’s behaviour and habitat,” said principle investigator  Amy Kukulya.

The team tracked three females and one male great white in the waters off Mexico’s Guadalupe Island. They collected over 13 hours of video data, giving a new insight into the animals behaviour and hunting strategies. The results of the research were published in the Journal of Fish Biology.

“Most of what we know about white shark predatory behaviour comes from surface observations. We have all seen pictures or footage of sharks surging out of the water to capture a seal,” said Greg Skomal, the papers lead author. “But we wanted to find out what was happening at depth, when the sharks swam into the deep, how were these animals behaving? Were they hunting? The REMUS AUV was the perfect tool to do this.”

 

In addition the the four sharks that the team tracked, the REMUS SharkCam also captured numerous encounters with other sharks that were not being tracked. Several behaviours were documented, including displays of territoriality and hunting.

“Predation events are rarely witnessed,” wrote the authors. “Virtually all of the published observations of predatory behaviour are based on surface interactions.”

The hunting behaviour that was observed gave a good insight into the stalking and approach strategies used by these sharks, demonstrating how they attack from deep, darker waters in order to take their prey by surprise.

The team is hoping to use a deeper diving REMUS in the future, allowing them to track sharks for longer periods, giving even more insight into the fascinating world of the great white shark.