April 14, 2024

Deep in the hostile waters off Canada’s west coast, in a narrow channel surrounded by fjords, lies a coral reef that scientists believe “shouldn’t exist”. The reef is the northernmost ever discovered in the Pacific Ocean and offers researchers a new glimpse into the resilience – and unpredictability – of the deep-sea ecosystems.

For generations, members of the Kitasoo Xai’xais and Heiltsuk First Nations, two communities off the Central Coast region of British Columbia, had noticed large groups of rockfish congregating in a fjord system.

In 2021, researchers and the First Nations, in collaboration with the Canadian government, deployed a remote-controlled submersible to probe the depths of the Finlayson Channel, about 300 miles north-west of Vancouver.

On the last of nearly 20 dives, the team made a startling discovery – one that has only recently been made public.

“When we started to see the living corals, everyone was in doubt,” says Cherisse Du Preez, head of the deep-sea ecology program at Fisheries and Oceans Canada. “Then, when we saw the expansive fields of coral in front of us, everybody just let loose. There were a lot of pure human emotions.”

Despite existing in absolute darkness, the lights of the submersible captured the rich pinks, yellows and purples of the corals and sponges.

The following year, the team mapped Lophelia Reef, or q̓áuc̓íwísuxv, as it has been named by the Kitasoo Xai’xais and Heiltsuk First Nations. It is the country’s only known living coral reef.

The discovery marks the latest in a string of instances in which Indigenous knowledge has directed researchers to areas of scientific or historic importance. More than a decade ago, Inuk oral historian Louie Kamookak compared Inuit stories with explorers’ logbooks and journals to help locate Sir John Franklin’s lost ships, HMS Erebus and HMS Terror. In 2014, divers located the wreck of the Erebus in a spot Kamookak suggested they search, and using his directions found the Terror two years later.

The remote-controlled submersible is lowered into the Finlayson Channel, British Columbia, Canada. Photograph: Cherisse Du Preez/Fisheries and Oceans Canada

The lophelia corals that make up the reef are typical of those found deep in the Atlantic and swaths of the Pacific south of California. The largest reefs can span several miles, and take tens of thousands of years to mature. In the case of q̓áuc̓íwísuxv, the reef spans 10 hectares (25 acres) of “thriving” corals.

“The Pacific has some of the oldest water in the world, meaning it has low levels of oxygen, which makes it hard for coral to survive,” says Du Preez.

The north Pacific also has high levels of acidity, which dissolves the calcium carbonate structures of coral. “So for the longest time, we didn’t think the components necessary to support a reef existed here,” she adds.

The team suspects the unique location of the reef, in a fjord with abnormally cold water, helps explain its ability to thrive. The ridge where the coral is found is also in an area of water column mixing, where highly oxygenated water is pushed down to the coral.

“At first you think a reef like this must be one of a kind. But it can’t be. That’s not how nature works. So now we’re going to find the other ones that must be out there,” says Du Preez.

Last week, Canada’s federal fisheries department announced all commercial and recreational bottom-contact fisheries, including mid-water trawl, could no longer fish in the area surrounding the reef.

Despite efforts to protect the area, dead coral found along the periphery of the reef highlights how lophelia coral is uniquely vulnerable to warming waters and increased acidification – hallmarks of a changing climate.

“These reefs are cemented to the rock and if you dissolve the base, it will literally slide off and crumble into the depths,” says Du Preez. “But if we can control all the activities that happen in the area, then we give this reef the best chance at surviving climate change – and maybe even colonising new areas.”

Beside the lophelia coral, researchers also found a large glass sponge reef. It is unlikely that the two species have met anywhere else in the world.

“In the deep ocean, there are no rules,” says Du Preez. “So you can get these two species living together, arguing or cooperating. Few things are more exciting for scientists than seeing things that seemed impossible happening right in front of us.”

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