Its pilots say it flies, but actually, it swims.
“The wings flop up and down as the waves go,” said Richard Davis, a Dalhousie University researcher, trying to simplify the contraption for his audience as they prepared to head out into the Atlantic.
The G5 wave glider is about the same height and weight as a very tall man — at least the part that floats. Underneath that, there is a seven-metre “umbilical cord” that attaches to a submerged glider, which does all the work.
It can move almost 40 kilometres a day, by remote control, propelled only by wave action. The wings are spring-loaded, turning the up and down of being tossed in the waves into forward motion.
Since June 19, Dalhousie has sent the G5 swimming from the Newfoundland and Labrador coast, through the Gulf of St. Lawrence, around the Cape Breton coast and then out closer to Sable Island. Then they told it to come home, fishing it out of the ocean near Sambro on Wednesday morning.
While it was away, it caught up with a salmon kelt in the Gulf of St. Lawrence, and some cod off Cape Breton, telling Dalhousie staff all about the water environment at the time. The researchers were hooked.
“We’re going to buy one, maybe two,” said Davis, as the small yellow glider dripped onto the ship’s deck.
The technology will provide data about fisheries and other aspects of ocean life in a way that hasn’t been possible, he said.
On the journey, sensors attached to the bottom of the glider collected information about salinity, temperature, ocean currents, weather patterns and more, as well as — crucially — the motions of passing sea animals, within several hundred metres, that are acoustically tagged.
It reported those findings by email or text message. The electronics are powered with solar energy.
Since 2008, Dalhousie’s Ocean Tracking Network has installed sea-floor data receivers in a line as far as 185 kilometres from Halifax, along the continental shelf.
“Those are listening for tagged animals,” said Davis.
But until now, to get that data, staff had to go out to the receivers by boat, haul them up or otherwise collect the information themselves, spending thousands on salaries and rented boats. Now the glider can fetch it.
The G5 costs about $250,000, but it will pay for itself relatively quickly, said Davis.
The oceans are home to tens of thousands of tagged fish, crustaceans and other sea creatures, said Ocean Tracking Network director Fred Whoriskey. Tracking their whereabouts is the best way to know where and when they spawn, where they migrate, and how to manage them.
“If you’re going to have an oil-drilling operation that’s going in to this part of the ocean there, but (which) also happens to be used by fish, and if we can figure out when the fish use it, and figure out a time of year when they don’t, then maybe you can drill for oil there, and have no impact on your fisheries,” Whoriskey said.
Away from the East Coast, the Ocean Tracking Network uses data receivers in spots where waters are warming quickly, including off Australia, South Africa and the Strait of Gibraltar. That worldwide data is also a way to learn more about the effects of global warming on sea life.
The wave glider was developed by California- and Hawaii-based company Liquid Robotics Inc., and there have been 140 sent into the world’s oceans in the past two years, said senior sales manager C. Eben Franks, who was on board to watch the G5 lifted out.
Others were sent to Puerto Rico to report on hurricanes or to the Arctic to report on carbon dioxide levels.
A group of four was sent to Hawaii to follow some great white sharks, and then it was split into two groups: two are now making for Japan, and two for Australia.