It’s Pick-up Time for HAK1-A

Fisheries and Oceans Canada retrieves its oceanography instruments from nine kilometers off Calvert Island.

Submerged beneath the waves off the Central Coast of British Columbia, a specialized piece of equipment resembles a sort of scientific Christmas tree. The topper star is a round buoy, which is suspended in the water beneath the ocean’s surface. Scientific instruments hang like ornaments along the heavy line down to a depth of 140 meters. One day in early July, scientists will finally get to open a year’s worth of data presents.

Last year, Fisheries and Oceans Canada researchers from the Institute of Ocean Sciences dropped this particular mooring—a line of oceanography instruments and sensors attached to an anchor—nine kilometers northwest of the Hakai Institute’s ecological observatory on Calvert Island. Unlike other ocean sensors that stream data back to scientists in real time, this mooring, dubbed HAK1-A, needs to be picked up to access the information.

On July 8, the Canadian Coast Guard vessel John P. Tully returned to pick up the mooring and download the oceanography data collected by the instruments over the past year.

The coast guard vessel sent a specific sound frequency down the water column to the acoustic release mechanism and the mooring’s instrument line floated to the surface. They grabbed the pick-up line and hauled it up.

“Examining these datasets will be interesting,” says Hakai scientist Jennifer Jackson. The instruments on the mooring measure a whole suite of variables including three-dimensional ocean currents, pH, temperature, salinity, and sounds produced both by humans and marine creatures.

Diagram by Josh Silberg

The relative proximity of the mooring to the Hakai Institute was no accident. As part of their regular rounds every three to six weeks, Hakai researchers collect zooplankton and other oceanographic data at a station less than a kilometer away, as well as at dozens of other sites dotted throughout coastal waters in the area.

This year, oceanographers are especially interested in cracking open the vault. “2016 was a strong upwelling year,” says Jackson, referring to the rise of cold, often nutrient-rich water from the deep ocean to shallower waters. Upwelling systems in California and Oregon have been studied for decades.

Watch the HAK1-A mooring as it gets dropped to the ocean floor in 2016. Video by Meigan Henry, Grant Callegari, Keith Holmes, Will McInnes, and Josh Silberg

“There are similar oceanographic moorings dotted throughout the British Columbia coast, but there were none in this area before this one,” says Jackson.

“We don’t know as much about how upwelling affects BC’s coast. This [mooring] allows us fill that gap, so we can better understand the complexities of this part of the BC coast rather than just estimate using information from elsewhere.”

After retrieving the mooring, the coast guard will drop another mooring with similar instruments to take its place. Next year, they’ll return and the process will repeat itself. Presents from HAKA-1 happen but once per year.