Experts are raising concerns that the destruction of Kamloops’ historic Red Bridge, which collapsed into the South Thompson River during a fire, could have an impact on fish populations.
Jason Hwang, vice-president of salmon programs at the Vancouver-based Pacific Salmon Foundation, said debris from the wooden truss bridge, which fell into the river on Thursday, could disrupt fish migration, particularly salmon returning to spawn in the fall.
“It’s a time of year when they’re coming through and using that spot in big numbers,” Hwang told CBC News. “Fish and the whole aquatic ecosystem are sensitive, especially to things that come off of fires with all kinds of chemicals like creosote.”
This year, concerns about salmon have intensified, given reports of declining sockeye populations in the region. The Pacific Salmon Commission recently noted that higher than average water temperatures and obstructions from the July 31 landslide in the Chilcotin River have already complicated salmon migration this season.
“These fish have been put through a lot,” Hwang said. “They’re now dealing with the effects of climate change and these localized issues can sometimes be that extra straw on the back of the camel that breaks things.”
British Columbia’s Ministry of Environment confirmed the bridge collapse released debris into the river, which is now being monitored by officials. In an update Saturday, the province said debris is still floating downstream, and log booms are being placed along the river to contain them. It said a company has been hired to oversee the removal of the bridge and plans to take down the unstable parts. A barge will be used to remove what’s left of the bridge.
Despite concerns, young fish have been spotted in the river and appear unaffected so far, according to the statement. Officials say water, air, and fish are being monitored, with no impacts detected at this time.
The federal Department of Fisheries and Oceans (DFO) said the historic bridge likely contained preservatives, which could increase the risk of harmful substances entering the water.
“We’re working to ensure that measures are in place to minimize the impact on fish and fish habitat,” DFO said in a statement to CBC News.
The federal institution says removal of debris will be handled carefully to ensure fish can migrate through the area during cleanup.
Firefighters refrain from using firefighting foams to protect salmon
Kamloops Fire Rescue Chief Ken Uzeloc told CBC News that crews are exercising caution while working to suppress the fire in the bridge’s wooden pilings, which were still burning in the river as of Friday afternoon.
“There are salmon right now in the salmon run, so we’re reluctant and very careful about using firefighting foam in that area,” Uzeloc said.
He noted that the wooden structure may be coated with creosote, an oil-based preservative that makes wood water-resistant.
Video taken by Kamloops, B.C., resident Nevada Woods shows the Red Bridge in flames collapsing into the South Thompson River around 4 a.m.. on Sept. 19, 2024.
“The wooden pilings are soaked in a creosote-type substance, so they’re going to be burning for a while and…it’s very difficult to get water on them.”
He added that he does not have an estimate for how long it will take to fully extinguish the blaze.
In June, a similar incident occurred in Richmond, B.C., when a decommissioned wooden trestle bridge caught fire after a warehouse blaze spread along the docks of the Fraser River.
Hwang was on site at the time to observe the impact of the burned bridge on the surrounding water.
“We didn’t see any obvious effects,” Hwang said. “Like, there weren’t fish turning over belly-up or obvious death of organisms.”
He noted the significant size of Fraser River likely helped dilute any harmful chemicals released from the creosote-treated wood.
The salmon biologist said he hopes the South Thompson River would experience minimal impact from the current fire.
The Red Bridge, built in 1936, connected Kamloops to the Tk’emlúps te Secwépemc reserve.
Kamloops RCMP say they are investigating the fire that destroyed the bridge as an arson.