A kill of fish in Bear Creek Park may have been the unintended result of Surrey firefighters' battle to extinguish a blaze at a nearby industrial plant.

Residents around the circuit manufacturing plant at 88 Avenue and 132 Street were evacuated Saturday evening amid fears they could be exposed to toxic smoke from burning chemicals and acids.

But trout and coho salmon that live in Bear Creek were less fortunate.

Large amounts of water used to fight the three-alarm fire ran off into the park, where dead fish were soon spotted floating in the creek.

"There was a massive fish kill," said local resident Gordon Scott, who on Sunday saw "hundreds of dead fry and yearlings."

Surrey Fire Chief Len Garis said he can't definitively connect the fire to the fish kill, but says it's likely beyond coincidence.

"There was a fair amount of runoff that took place," he said. "Whether or not it was some of the products that were stored in that building or whether it was turbidity or chlorine concentrations of the water that was used, I couldn't tell you."

Garis said the fire department notified the Department of Fisheries and Oceans and the provincial and federal environment ministries.

"It's one of the unintended consequences of these types of situations," he said, adding it's unclear what more could be done.

"We're pouring thousands of gallons of water on a fire and there's going to be runoff. I can't for the life of me tell you how we're going to contain that."

He had no estimate of the number of dead fish but City of Surrey utilities, drainage and environment manager Carrie Baron said "a lot" of dead juvenile fish were found in different pools of the park.

She said skimmers can be used to pick up spilled oil and in some situations water used in the mopping up phase can be rerouted through the sanitary sewers, instead of storm drains.

But Baron said it's difficult to control water runoff while a fire is raging.

Blocking storm drains leading to Bear Creek would likely have caused the water to back up and find a different route to the park, she said.

Scott argues the city should do more, noting street drains near the park had recently been plastered with fish habitat warnings imploring residents not to contaminate the sewers.

He says the city and fire department were negligent not to take better steps to protect fish when a fire occurs near a salmon stream.

"It's all about the optics – nice pretty plaques while our fish bob upside down in our showpiece park," he said.