UPWARDS of 100 dead and dying coho salmon were found in Mackay Creek July 8, but just what killed them may never be known.
Ron Den Daas, a member of the Pacific Streamkeepers Federation, discovered the fish when he took some kids down to the creek to show them the young salmon, only to happen upon the much more grisly scene. He described salmon gasping, unable to swim and floating to the top, with several still dying in front of him.
"It was horrible," he said. He walked up and down the banks with staff from Environment Canada, the provincial Ministry of Environment and Fisheries and Oceans Canada, counting in total about 100 dead fish. The die-off in a small ecosystem will have a huge impact, he said.
"Because Mackay Creek is a very impacted urban creek, the salmon population that lives in Mackay Creek is really struggling to survive," he said. "It will impact the return, who knows how much, but when it's already struggling this doesn't help, for sure."
Environment Canada is investigating the deaths and conducting tests on fish samples at their West Vancouver facility, but by the time Nick Russo, acting manager of environmental emergencies, reached the site, water tests came back within normal limits.
It's often difficult to pinpoint an exact source of what killed the fish, he said, because of how many different storm drains feed into creeks like Mackay.
"Whatever that material was that caused the fish kill could have come from anywhere," he said.
Poisoning via storm drains is not uncommon. In July 2010, an unknown amount of fire-retardant foam was flushed down a storm drain at North Vancouver District's No. 3 fire hall on Montroyal Boulevard and wound up in Mosquito Creek. The chemical, called Hi-Combat A, coated the surface of the creek in bubbles, but wasn't blamed for any fish deaths in the creek.
"Urban creaks are hit hard every year. It's not just Mackay Creek. I've worked extensively with the city of Burnaby over a couple of years to resolve issues on Byrne Creek, and it's just one of those ongoing things," said Rucco, adding it's a frustrating job at times to respond to these fish kills year after year.
If there's a moral to the story, he said, it's that people need to watch more carefully what they do with their household products. Even products that say "environmentally friendly" or "biodegradable" on them can be dangerous to fish in certain concentrations, as can prolonged exposure to the chlorine in tap water.
"Any sort of waste should be disposed into the sanitary line: your sink, your toilet, that sort of thing," he said.
It's a message Den Daas couldn't agree with more, adding people often think storm drains enter the sewer system when they actually dump into streams.
Still, he hopes to see Mackay Creek bounce back, describing it as an invaluable resource for the North Shore.
"I bring a lot of kids to the creek to do programming with local schools about salmon and protecting the creek, so for me it was a total disaster and a very troubling event."
