The oil leak into the Colquitz River is probably from B.C. Hydro transmission cables, but only a small amount of insulation oil has reached the water, Hydro spokesman Ted Olynyk said Friday.
"It's highly likely it's coming from our cables. ... We are monitoring through the weekend and it has been contained. We'll do any repairs that are needed next week," he said.
About one or two litres a day has been leaking over the last two days during the monitoring period, Olynyk said.
The good news is the oil is unlikely to hurt wildlife, he said.
"It's a mineral oil with very, very, very low toxicity. There should be no impact on fish," he said.
Adriane Pollard, Saanich environmental services manager, said Saanich, as the first responder, will hand over cleanup responsibility to Hydro.
"They will need to get a plan in place because there are many options and they have to decide what's best in terms of long-term impact," she said.
No dead or sick fish have been seen, said volunteer Colquitz River steward Dorothy Chambers.
However, the large numbers of coho salmon gathering in Portage Inlet are acting oddly, she said.
For the last two weeks almost all the coho have chosen to go into Craigflower Creek instead of Colquitz, even though Colquitz usually has the much larger run, Chambers said.
It is a good year for coho on southern Vancouver Island and, so far, about 500 coho have swum through the Craigflower counting fence and 70 into Colquitz.
Usually those figures would be reversed, Chambers said.
"Salmon have an acute sense of smell and it seems our salmon are being turned away at the source," she said. "But I'm thankful they are surviving. They are the same genetic fish."
No one knows whether the fish are reacting to a slow leak from the Hydro cables or residual oil from the 1,000 litres of home heating oil that spilled into Swan Creek and then into the Colquitz River last year, Chambers said.
"My feeling is it is probably oil trapped in the vegetation and, now we have rain and faster running water, the oil in the tree roots and vegetation is being released," she said.
Last November's spill was followed by a February spill of 634 litres of home heating oil.
There were already worrying signs this spring that those spills have had a lasting effect, Chambers said.
"This year there were no smolts leaving Colquitz.
There are usually thousands and there were zero - none," she said.
There were also no scud shrimp this spring, indicating that creatures living in the bottom mud and under rocks, which provide food for fish and birds, were affected by the oil, she said.
