A new autonomous underwater vehicle (AUV) will allow researchers to explore Canadian waters in previously unimaginable detail, offering up a deeper understanding of everything from conservation efforts to animal habitats to the impacts of climate change.
“This vehicle will allow us to collect data we otherwise wouldn’t have. It was unattainable,” Biology professor Brian Branfireun explained.
In partnership with Wilfrid Laurier University, University of Waterloo and the Toronto-based environmental charity Georgian Bay Forever, the approximately $350,000 AUV will revolutionize water-quality monitoring through more efficient measurements of lake chemistry and mapping of underwater physical characterizations of bodies of water as far as the Northwest Territories.
The compact AUV is not only sophisticated in terms of the type of data it can collect, but also in the fact it requires little human support. The vehicle can be launched from a dock, run night or day underwater for 8-10 hours, up to depth of 100 metres (328 feet) and return to a programmed location for retrieval.
“We’re now able to study areas where access had been limited for a boat,” said Branfireun, Canada Research Chair in Environment and Sustainability. “You can bring this vehicle in by float plane or ATV or carry it in somewhere if you needed to. You can hike with it right to the lake.”
Branfireun admitted to some nerves when he took the AUV out for its maiden voyage last month at Fanshawe Lake. “It’s quite disconcerting to effectively press go and just let it go,” he laughed.
But some flashy options, like a hydrophone pinger detector built for an emergency location and an iridium transmitter to send location signals when it surfaces, put Branfireun’s mind at ease.
“It’s a fully autonomous vehicle once you program it. You tell it take this pattern, take these measurements, and it will run for up to 10 hours to do what it has to do, and then return to wherever you tell it. It’s great.”
Branfireun said millions of lakes in Canada remain completely uncharacterized simply because of the ability to get accurate data. With the AUV, that will be a thing of the past. “I don’t think there’s probably more than a thousandth of a per cent of surface waters in Canada for which we actually have an accurate map of the bottom,” he said. “We don’t even know how deep most small lakes are in Canada.”
Using sonar, the AUV can measure water depth and bottom topography, while simultaneously using water-quality sensors in the nose cone to measure everything from PH levels and water temperature to the conductivity levels in dissolved oxygen.
“That’s information you can’t get just from the surface. It’s all about getting data we couldn’t get without an autonomous instrument like this,” Branfireun said.
“There’s a richness to obtaining this type of data. It removes a level of inference we would have to make otherwise. Where we would go to the middle of the lake, measure all these things, it’s just up and down in two dimensions. Now being able to capture this is 3D is something that will give us a better sense of things.
“It’s probably fair to say, in most lakes, we don’t have any idea what the distribution of water chemistry is. We make assumptions about them being pretty uniform – but they are not, of course.”
Think about fish habitats, Branfireun offer as an example. The most important data involves the bottom topography of the lake, including details like depth, and temperature. These vary widely from lake to lake and are the difference between the water being able to continue support certain fish.
“From a fisheries perspective, there’s a lot of important information there,” Branfireun said citing an example of lake temperature in the Northwest Territories (NWT) already climbing to 16-18 degrees C near the surface.
“These are sub-arctic, high-altitude lakes. For things like lake trout, that’s starting to get close to the thermal tolerance. There are going to be many lakes in the northern Canada that don’t support the fish populations they currently do. It would be nice to be able to have a sense of what the trajectory is going to be.”
The data collected, he explained, will allow for climate change adaptations for fisheries and those relying on traditional foods in the north.
For the AUV’s first research mission, Georgian Bay Forever volunteers will take detailed measurements throughout the bay to look at the efficacy of their restoration efforts. The vehicle then heads to Waterloo researcher Heidi Swanson before Branfireun will employ it for research within the grassy narrows of lakes in northern Ontario, as well as additional work in NWT and the Yukon.