The death of potentially thousands of pink salmon in the Cheakamus River has prompted questions about how BC Hydro manages water levels in some of its reservoirs.
It happened Thursday night and into Friday morning, when the Crown corporation reduced the spill release from the Daisy Lake Reservoir into the river, stranding fish who had moved closer to the banks.
“I was taken aback, I couldn’t believe what I saw,” professional angling guide Clint Goyette told Global News.
“The amount of dead and dying fish was something I’d never seen before in the adult phase of life of these pink salmon.”
BC Hydro says it had increased outflow from the reservoir into the river earlier in the week, as the South Coast was battered by a heavy rainstorm.
Once the storm let up, it says it began to “slowly reduce flows” on the river, a “ramp down” process completed on Saturday.
“Our ramp down plan follows the protocols discussed with First Nations, stakeholders and agencies developed through the Cheakamus Adaptive Stranding Protocol (CASP) over the past few years,” a spokesperson said in an email.
“The plan is consistent with the Department of Fisheries and Oceans guidelines. It applies ramping rates with smaller changes over longer periods of time to allow fish movement from potential stranding sites.”
The power company added that crews were on site to try and move fish from any areas likely to be “dewatered,” and to save as many stranded fish as possible.
It said there was not a firm estimate yet on the number of fish stranded, but that there would be a debrief with local First Nations and stakeholders to improve future ramp downs.
Goyette, who along with a number of other local volunteers spent hours on Friday trying to save as many fish as possible, said he only saw two BC Hydro employees on the river.
He said the company needs to do better, particularly given a similar mass-stranding on the Cheakamus two years ago, brought about by the same type of post-storm river draw down.
“I think they need to take a good hard look at how they deal with these rain events — they’re nothing new,” he said.
“Here we are two years after the last adult kill, and we’re in the same boat, the same scenario has occurred … what do we need to do to prevent this from happening in the future?”
Jonathan Moore, an SFU professor and head of the school’s Salmon Watersheds Lab, said the incident highlights the tricky balance a company like BC Hydro faces as it tries to manage a watershed.
“This event though does showcase that there’s continued need to work on this in order to avoid events like this — and there is a history of this type of event in this watershed,” he said.
“Hopefully this will be given a hard look at, but I imagine if the water was ramped down more slowly, at a rate that wasn’t as fast, then this might not have happened.”
Moore said it was too early to assess what potential impact the die-off could have on the local pink salmon population’s viability, but that both adult and juvenile fish from this year’s run could have been affected.
“Fish could have gotten killed, but also their nests or their ‘reds’ could have gotten dewatered. This is an important time for salmon,” he said.
Moore said the incident raises several questions, including whether protocols were properly followed in reducing water levels, whether those protocols need to be reviewed given the higher frequency of storms amid climate change, and what the cumulative impact of repeated strandings has on the salmon population.
It’s a question Goyette also raised, noting that the salmon populating the Cheakamus are also a crucial contributor of food and fertilizer to the entire region.
“If you interrupt this lifecycle, we’re going to lose nutrients, we’re going to lose the ecosystem essentially,” he said.
“They’re a critical species here — this is ridiculous.”