A Buoy’s Winter Tune-Up

Before resuming its role as a vital data collector, this buoy needs a thorough cleaning.

Even the most resilient environmental sensors need an occasional tune-up. The Kwakshua Channel (KC) buoy, located on the Central Coast of British Columbia, is no exception. The last 20 months have kept the hardworking buoy busy; in an area where year-round data hadn’t been previously available, it was charged with taking daily oceanographic measurements that scientists around the world use to track ocean acidification. So when it came due for maintenance, scientists had to act quickly, lest they miss an important change in the environment.

“There’s never a great time to pull out a buoy,” says Hakai oceanographer Wiley Evans. Ocean conditions vary in the fall and spring, and finding a spare moment during the busy summer season can be tricky. “So, winter it is.”

That time of year has its own challenges, though.

“It’s hard enough working on the water, but when it is that cold your hands freeze up,” says Hakai technician Katie Pocock.

In early January, a small crew gathered around the buoy and put their plan into motion. Simply pulling the buoy out of the water was not going to work; old train wheels anchored it to the seafloor with four tonnes of metal. So, the team used the buoy’s built-in mechanism for retrieval: a special acoustic release. Dispatching a unique sound code detaches the buoy from its anchor. After that, the team waited for the “hard hat” floats—glass balls with a hard canary-yellow casing—to reach the surface to indicate the buoy successfully detached from the anchor.

“It was this suspenseful moment,” Pocock says. “Is the acoustic release going to work or not? It took a bit longer than expected, but we all breathed a sigh of relief when it finally came up.”

With their main worry out of the way, the buoy was transported ten kilometers down Kwakshua Channel to the dock at Hakai’s Calvert Island ecological observatory. There, the buoy got picked up and brought to Port Hardy by the barge the M/V Central Coaster. Technicians checked the hardware, replaced parts, and gave the buoy a fresh coat of paint. The special CO₂ sensors traveled farther to Quadra Island for a system check and refurbishment before the whole system heads back to sea, where it will continue to measure the ocean’s vitals.

All that data it collects will be put to good use. In January, it contributed to a package of submissions from the Hakai Institute totaling more than 750,000 oceanographic measurements to the Surface Ocean CO₂ Atlas (SOCAT), a global dataset used in the annual assessment of global carbon budgets that informs Intergovernmental Panel on Climate Change (IPCC) reports.

“It’s really getting to the highest level,” Evans says. “The fact that we’re able to contribute to these global projects—that makes me proud.”

Acknowledgements

The KC Buoy retrieval and maintenance would not have been possible without the logistics planning and hard work of Shawn Hateley, Katie Pocock, Chris Mackenzie, Jessy Barrette, Nick Sinclair and Wayne Jacob.