BB’s First Mission

An ocean glider collects valuable data in the midst of a pandemic.

Gathering data from the comfort and safety of your home is the perfect way to do science in a pandemic. Out in Queen Charlotte Sound off British Columbia’s Central Coast, BB the SeaExplorer glider makes its steady way back to shore, while a team of researchers dispersed along the coast readies for its return, awaiting the valuable data and lessons it brings. Launched from Calvert Island, piloted from Nanaimo, and guided along its route by constant online communications, BB’s first open ocean mission is a collaborative long-distance effort.

Named after BB-8, the peppy orange-and-white ball of robotic energy from the newest Star Wars trilogy, this sea worthy robot is returning to Hakai’s Calvert Island Ecological Observatory from a three-week journey that took it past the edge of the continental shelf, about 130 kilometers from shore. This was a mission of firsts: BB’s first mission, the team’s first mission with this make of glider, and the first true glider mission deployed from the coastal waters off Calvert.

It was also the first mission launched from Calvert Island since the COVID-19 pandemic began and the surrounding Hakai Lúxvbálís Conservancy was closed. With an exemption from BC Parks to continue critical research, operations at the Calvert Island station have been pared down to the essentials needed to keep long-term monitoring programs running while also minimizing travel to the island. Luckily this mission fits the bill: while remote operation is a given with gliders, it’s this very feature that allows these researchers to safely continue to collect oceanographic data.

“You don’t have to worry about the pandemic on a glider. It just is out there autonomously collecting data, and you just need one or two pilots who are working remotely to control it,” says Hakai oceanographer Jennifer Jackson. She notes that on a research vessel, one case of COVID-19 could quickly spread. Not so with an autonomous, remote-operated glider: “It’s social distancing at its best.”

And so far, so good. “If things are going to go wrong, it’s usually in the first few days,” says Hakai research technician Chris O’Sullivan.

After its launch from the waters west of Hakai Pass on July 17, BB made its way westward through an underwater canyon known as Goose Trough, which connects the shallow coastal waters of Queen Charlotte Sound to the deep waters beyond the continental shelf. Over a series of dives that reached 1,000 meters deep and lasted for more than six hours, BB collected vital oceanographic measurements that will help researchers better understand the mechanisms driving coastal upwelling processes in the region.

“How upwelling works in Queen Charlotte Sound is still very much an active research question,” says Jackson. “We know that the waters offshore are really well-correlated with the waters in Rivers Inlet,” a 45-kilometer-long fjord on the Central Coast. “We know Point A and Point B are really similar—we just don’t really know what happens in between, and that’s almost 200 kilometers apart.”

Upwelling that occurs further south, in the “upwelling centers” along the coasts of Oregon and Northern California, is driven by summer’s northerly winds. These winds push warm surface waters offshore, across the narrow continental shelf. This offshore flow forces cold oxygen-poor, but nutrient-rich waters from the deep ocean to mix up into the surface layer. The nutrients and phytoplankton stirred up from the depths feed the base of the coastal marine food web.

But this process becomes more complicated and less predictable in the waters off the Central Coast. “As you head further north, what we think of as upwelling actually weakens,” says Jackson, referring to the typical wind-driven process.

In Queen Charlotte Sound, weaker upwelling winds and a wider shelf mean the outflow from streams and rivers along the Central Coast plays a greater role in upwelling: the mixing of fresh and salt waters, driven by their different densities, enhances the flow of warmer surface waters away from shore. But this rush of fresh water into the nearshore creates currents that move in a complex manner, making it difficult to accurately predict coastal conditions even in the near future.

“The physics of what happens there is not difficult, but it is actually difficult to get into a good predictive model,” says Jody Klymak, a professor of physical oceanography at the University of Victoria and the project’s principal investigator.

The continuous, repeated stream of fine-scale data collected by BB on this and future trips along the same route is key to improving this understanding. It will help researchers better understand the processes at work, refine their predictive models to be more accurate, and provide a clearer picture of what oceanographic conditions will look like in the waters of Rivers Inlet weeks and months in advance. And since conditions in these nearshore waters underpin so much of coastal life, gaining this foresight is invaluable. In a time when many research programs are constrained by the pandemic, that data collection is especially priceless.

While this is the first of hopefully many missions for BB, what the glider has already pinged back to shore has piqued the scientists’ interest. “I think we’ll see lots of cool things once we do [run repeats throughout the year], but even this first section is really neat. We’re quite excited by it,” says Klymak.

After its successful retrieval near Calvert Island, BB will get a check up and battery recharge, then be sent back out into Goose Trough for another autonomous run out to sea.

Acknowledgements

This ocean glider research is part of the Canadian-Pacific Robotic Ocean Observing Facility, or C-PROOF—a collaboration between the University of Victoria, the University of British Columbia, Fisheries and Oceans Canada, the Hakai Institute, and Ocean Networks Canada.