A Ukrainian teen enthralled by live images from an underwater camera off Vancouver Island has helped unravel the mystery of how deep-diving elephant seals eat a seemingly inedible fish.
At first, Kirill Dudko of Donetsk, Ukraine, didn’t know what he had seen.
The 14-year-old was watching live Internet video of a hagfish slide toward a camera in Barkley Canyon when a nose and whiskers appeared in the frame and something inhaled the hagfish.
“It was like a horror film,” the biology enthusiast wrote in an email to the University of Victoria, the dry-land home of the NEPTUNE Canada deep-sea camera network.
“This creature wasn’t like a fish and I realized it was a mammal because of the nose and moustache.”
In an email to the Times Colonist, Dudko said he was perplexed because he did not think any mammal except a whale could dive to such a depth — the camera is 894 metres under the sea.
“But it did not look like a whale,” he said.
Kim Juniper, NEPTUNE associate science director, said the encounter could easily have been missed without Dudko’s keen eye.
“He was clever enough to know he had seen something unusual,” said Juniper, adding that the NEPTUNE program encourages citizen scientists to help sift through massive amounts of data collected from the 800-kilometre undersea loop of fibre-optic cable.
“But we didn’t expect that a 14-year-old would be making a discovery like this on his own,” he said.
After looking at the video, Juniper consulted marine mammal experts at Fisheries and Oceans and Oregon State University and concluded that the mysterious diver was a female northern elephant seal.
“They are the only seals known to dive that deep,” he said. “They’re not so much a diving seal as a surfacing seal. They spend 90 per cent of their time under the water.”
Although GPS transmitters have recorded the deep dives, the video is the first visual evidence of how they spend their time underwater, Juniper said.
But what has caught scientists’ attention is how the seal ate the hagfish, an eel-like, eyeless, mucous-producing creature that even sharks and conger eels are unable to eat it because it clogs their gills.
“They secrete so much slime that it turns water in a five-gallon bucket into jelly,” Juniper said.
The slime-producing pores help the hagfish worm into the bodies of injured and dead whales and large fish, which it then eats from the inside out.
“It’s not a pretty sight,” Juniper said.
Hagfish have been found in the bellies of dead elephant seals before, but it was not known how the seals eat them without gagging on the slime — until now.
“Now we know she didn’t bite or chew, she inhaled it,” Juniper said. “She created a low-pressure vacuum around her mouth.”
The ocean at that depth is dark, and elephant seals would usually use their whiskers as sensors. But the one in the video had the sense to hang around when the lights were turned on briefly for the camera, Juniper said.
The area is lit up for only five minutes every two hours to avoid creating artificial conditions. “Otherwise it would be a bit like watching bears at the dump,” he said. …