Dead fish in creek near Eagle mine likely killed by cyanide, Yukon officials say

Officials with the Yukon government say dozens of dead fish found earlier this week in a creek near Victoria Gold's Eagle mine were likely killed by a discharge of contaminated water from the mine site.

At a briefing on Friday morning, government officials and scientists said Victoria Gold personnel discovered at least 68 dead Arctic grayling and slimy sculpin in Haggart Creek on Aug. 2.

Officials said contaminated water discharged by Victoria Gold between July 31 to Aug. 2 is the most likely culprit. The company has been responding to a major failure that happened in June at its heap leach facility at the Eagle mine, releasing cyanide into the environment.    

Over the weekend, the company was ordered to construct a series of barriers to protect fish, and voluntarily stopped discharging water from the mine treatment plant.

"The death of a large group of fish like that, of multiple species, in a really short period of time is completely consistent with what we would expect from cyanide toxicity," said Dr. Mary Vanderkop, Yukon's chief veterinary officer, at Friday's briefing. 

It's unclear whether the water discharged from the mine site was released deliberately, or whether it had been treated at all. CBC News requested a comment from Victoria Gold but did not receive a response by deadline.

In a July 30 news release, the company said it had "augmented water treatment capacity on site."

Asked by a reporter on Friday whether the discharge of contaminated water was unintentional or unexpected, a government spokesperson said that was "outside the scope" of the briefing. 

Following reports of dead fish, Fisheries and Oceans Canada issued a legal order for Victoria Gold to construct seven fish barriers throughout Haggart Creek. 

They were also ordered to "salvage as many fish as possible" downstream, said Yukon Government fisheries biologist Cameron Sinclair on Friday.

Officials hope to establish a "no-go-zone" to help fish to avoid the areas most affected by the discharge event. Sinclair acknowledged that this may disrupt fish migration patterns.

The First Nation of Na-Cho Nyäk Dun has requested a long-term monitoring plan to understand impacts on fish as well as the spread of heavy metals in the environment through other animals such as moose and caribou.

Vanderkop said on Friday the government will be collaborating with the First Nation to put those plans in place.  

"In order to support the testing for these metals, we have put out a request to those that will be harvesting north of Mayo," she said.