Once upon a time, salmon were so abundant in the river that old-timers say they could make the crossing on the backs of fish so thick they resembled stepping stones. The Cowichan River, which flows east on Canada’s Vancouver Island, was so famous that its fly-fishing conditions were featured in fishing clubs in London. John Wayne and Bing Crosby were regulars at Cowichan Bay.
So when hundreds of smolts and trout were found dead in the river last month as record fires raged across Canada, the news made the front page of the local newspaper. The death, the largest in living memory, quickly led to an investigation.
It remains a mystery. Government officials found partially treated sewage in the river a few weeks after the fish were found, but they have yet to draw any conclusions about its impact. Local scientists suspect the bigger culprit is climate change, which has contributed to the decline of British Columbia’s salmon populations due to increasing droughts and heat waves.
In a summer of global catastrophe for Canada, climate change is being felt across this vast country – from Cowichan Valley on the Pacific coast to Halifax on the Atlantic Ocean, from the long border with the United States to the remotest cities above the Arctic Circle. But while the world has been consumed by the fires raging in Canada’s forests and turned into tinderboxes by the effects of climate change, the river’s plight has hit close to home in Cowichan Valley.
A biologist, who swam in a wet suit miles downstream from where the young fish, or fry, had been found, discovered hundreds more dead in pools at the bottom of the river. Farther downstream, past eerie “arid zones” where there were no fish at all, he found dozens of dead adults in larger, deeper pools—deep rainbow trout and even larger brown trout.
“It was the first time, not just in my career, but the first time in my life, that I had seen anything like it,” said biologist Tim Kulchyski, 50, who said he “actually grew up in the river” a member of Cowichan Tribes, where he now works as a natural resources expert.
The mass death of the cold-water fish has occurred during another summer of extreme drought and heat on Vancouver Island, a region known for its temperate climate. Wildfires closed off access to some of the island’s western communities for more than two weeks during the tourist season, leading to losses estimated by a local chamber of commerce at about $30 million.
The country has had a summer full of extreme weather conditions and record temperatures. Inuit communities, some of which are above the Arctic Circle, have broken records with temperatures above 90 degrees Fahrenheit.
With the wildfire season still at least a month away, the fires have burned the equivalent of the area of the state of Georgia, about 38 million acres of forest, more than seven times the annual average. The fires have forced nearly 200,000 Canadians from their homes this year and have led to the mobilization of thousands of foreign firefighters to help. Experts have called for a fundamental rethink of Canadian forest management and firefighting.
In Cowichan Valley, the effects of the drought across the province are most visible in the river, which has sustained indigenous communities for centuries and helped grow local industry and tourism. The Cowichan ecosystem, recognized as a Canadian Heritage River, can no longer survive without direct human intervention, experts and local groups say.
“There’s a lot of talk about climate change, but if you live here there’s no denying it,” said Tom Rutherford, salmon biologist and executive director of the Cowichan Watershed Board.
“We have never had such a large fish kill in the Cowichan River, or at least in living memory,” said Mr. Rutherford. “The event is still under investigation. But if there had been more water in the river, if it hadn’t been so hot, the consequences would have been less. Salmon is a cold water species. Things may not have brought them over the edge in the past. Now they do.”
Government investigators found partially treated sewage from a local treatment plant in the river 14 days after the dead fry were first discovered, but have not yet reached any conclusions about its “toxicity” or “impact on fish,” an Environment spokeswoman said. and Climate Change Canada, a federal department.
In recent years, the government and other experts have warned that increasing droughts, heat waves and heavy rainfall, exacerbated by climate change, are leading to the sharp decline in British Columbia’s salmon population, especially of species that spend more time in rivers. Thousands of salmon have been found dead in rivers and creeks on the province’s Pacific coast amid severe drought over the past two years. The stress of a changing habitat also weakens the fish and makes them more likely to die from other causes, experts say.
From its source at Cowichan Lake, the river flows for 30 miles across southeastern Vancouver Island, in one of Canada’s most fertile areas, past forests once filled with towering cedars and Douglas firs before emptying into the Salish Sea . The Cowichan was the perfect habitat for chinook, chum, and coho salmon, which could feast on insects and swim in cool water under the shade of trees.
The local indigenous communities, according to their cosmology, are the people who descended from heaven to earth, where they found a river full of salmon. The river and the salmon were central to their way of life and spirituality, said Lydia Hwitsum, the chief of the Cowichan tribes.
“The river and everything within the river are considered part of our family,” said Chief Constable Hwitsum. “And it is our corresponding responsibility to watch and take care of it.”
Logging began in Cowichan Valley after the arrival of European settlers in the mid-1800s, and continues today. A weir was built at Cowichan Lake in the 1950s to provide water storage for a paper mill, storing and releasing water during the dry months.
Residents in their 60s and older remember seasons of steady rain that fed the Cowichan and its tributaries, and cool, often overcast summer months that kept the waters favorable for young salmon and trout. Some remember jumping off an old railroad bridge nicknamed “Black Bridge” into the river—where the water was now perhaps a foot deep.
The logging has cut down many ancient giant trees that kept the river and valley cool and helped absorb the rain that gradually drained into the river, experts say. Now the rains have become irregular, often releasing huge amounts of water that cannot be absorbed into the soil. Due to the warmer weather, the snow layers melt faster, leaving less water for the river in the summer.
Joe Saysell, 75, a fishing guide who has lived along the river all his life, said the shape of the Cowichan has changed over his lifetime, becoming wider and shallower, with the bottom increasingly covered with gravel and less with the medium-sized rocks under which fry can feast on insects and hide from predators.
When a heat wave in mid-August brought days of mid-80s temperatures to the region, Mr Saysell said: “The poor fish are just baking.”
Mr Saysell, a retired logger and founder of the Friends of the Cowichan, a private organization set up to protect the river, was one of the first to see the dead boy last month after being alerted by a friend who lived with his husband in the river swam. daughter.
“This river is in the emergency room, with a bunch of doctors doing everything they can to keep that patient alive,” he said.
To conserve water amid a severe drought, Lake Cowichan’s runoff was restricted to the lowest possible level this summer. About ten days before the dead cubs were found, the water flow in the river had been reduced by more than a third.
The decades-old weir is unable to provide enough water in the era of climate change, said Mr Rutherford of the Cowichan Watershed Board.
The Cowichan Watershed Board is pushing for a larger weir to be built that could store more water for the dry months, Mr Rutherford said. With local government climate projections predicting hotter, drier summers and warmer winters, more human intervention will be needed to keep the Cowichan alive, experts say.
In the past, the Cowichan River experienced periods of drought, but it always recovered. Today, that’s no longer possible, said David Anderson, who was federal environment secretary 20 years ago and serves on the board of directors.
“Nature corrects itself, but cannot correct itself if man puts himself in nature’s place and makes decisions that run counter to any possible recovery,” Anderson said. “We are in a different world. We simply take too much from the global environment.”
