The nuts and bolts of studying Nunavut waters

The ocean observatory perches on top of an Adlair Aviation pick-up truck. (SUBMITTED PHOTO)

Two University of Victoria divers prepare to raise the ocean observatory. (SUBMITTED PHOTO)

Raising an awkward shaped, 250-pound device connected to hundreds of feet of fluorescent ethernet cable from the icy Arctic waters is no simple task.

But a team of divers and young researchers with the University of Victoria did just that Sept. 16, when they retrieved their ocean observatory from the seabed near the dock in Cambridge Bay.

The water temperature that day was 1.9 C — and would, in fact, start freezing up the next day.

But, protected by drysuits, two divers managed to bring the pyramid-shaped mechanical device up to the surface and then hoist it onto the dock, with assistance from Jorgan Aitaok of Nunavut Tunngavik Inc. and several others in the community.

By then, the September sun was setting over the Cam-Main Distant Early Warning line site to the west, leaving little time to take apart the observatory for storage overnight as planned.

With volunteer logistical support from an Adlair Aviation pilot, the team managed to lift the platform into the air charter company’s pickup truck and transport it to the airport hangar for safe storage.

When underwater, the observatory measures such things such as water temperature, sound, salinity and ice thickness. It’s also equipped with a camera to keep an eye on the seabed.

Similar observatories have been installed off the coast of British Columbia as part of Ocean Networks Canada, a University of Victoria-based project which, according to its website, “operates world-leading cabled ocean observatories for the advancement of science and the benefit of Canada.”

Cambridge Bay’s observatory could be the first in a series of devices to monitor changes in the Arctic, the website says.

Launched in September 2012 — and visited by Prime Minister Stephen Harper last month when he was in Cambridge Bay, the observatory is expected to contribute to a baseline of environmental data such as the rate of ice growth and the timing of algae blooms.

This year, among other things, the team plans to service and reinstall:

• an underwater high definition video camera;

• an acoustic ice profiler; and,

• a fish tag receiver from the Ocean Tracking Network.

They also plan to install new instrumentation, including a sensor which will measure underwater light levels.

On shore, a video camera will continue to monitor surface ice formation and a weather station will provide real-time atmospheric conditions.

An antenna positioned on top of a nearby building will continue to identify signals from nearby ships and capture their location, a project website says.

Divers with the team plan to sample fauna on the seafloor and determine a new observatory location for 2015.

They expect to position the underwater sensors further from vessels and winter road traffic near the busy Cambridge Bay dock.

Among interesting tidbits learned so far from studying data collected by the observatory: while winter air temperatures in Cambridge Bay frequently dip below -30 C, water beneath the ice remains near 0 C.

Then, during the summer, prolonged sunshine raises air temperatures and melts the ice, causing seawater temperatures to approach 10 C.

And in November 2013, the observatory recorded the sound of ice cracking as a snowmobile travelled over the ice near the Cambridge Bay hydrophone. The snowmobile broke through the ice a short time later.

Before the team leaves Cambridge Bay, its members plan to meet with students and teachers at Kiilinik High School, invite locals to see them relaunch the observatory into the water from the dock and hold a public meeting to tell people in the community more about their work and the observatory.

(with files from Cambridge Bay)