There was a flicker of hope last week that salmon had finally returned to spawn in Bowker Creek after more than a century.
Two coho salmon were mysteriously found dead in the shallows of the urban waterway, which has been painstakingly restored at its lower reaches near Oak Bay Marina and restocked with incubated fish over the past three years.
But a director with the Friends of Bowker Creek Society said the appearance of the near pristine, silvery coho was either a good-natured, well-placed prank or just a couple of fish who got the wrong spawning address.
Gerald Harris said it could also be that the two coho — if they did get their evolutionary wires crossed on their home streams — died from lethal chemicals from a tire preservative that’s been known to kill salmon in streams near roadways.
“It’s a puzzlement, but we’re hopeful about salmon returning,” said Harris.
The dead coho have been sent to 91原创 Island University for analysis to see they they were killed by 6PPD, a rubber preservative that is toxic to fish and linked to previous mass coho kills.
The Friends of Bowker Creek also have the water from the creek regularly tested by University of Victoria grad students for quality and pollutants.
Bowker Creek has been populated the past three years with incubated chum salmon, not coho, so the appearance of dead coho came as a surprise to conservationists who have been keenly watching the creek for weeks now, hoping for the first chum to return and spawn.
“My thought is that even though salmon have this amazing homing instinct, there are always some who get it wrong and end up in the wrong place,” said Harris, a former DFO employee and fisheries consultant.
“And really that’s an evolutionary advantage. They have this wonderful wandering capacity to repopulate streams that either had fish at one time or did not.”
Harris said as glaciers retreat in Alaska and new streams and rivers have been formed, those are being populated by salmon all the time.
“So it’s possible here,” he said. “If 20 or 30 years from now, people can make this a decent habitat for coho, too, they will find it.”
In the meantime, Harris and other volunteers who work on Bowker Creek have their fingers crossed for the thousands of chum salmon that have been hatched in the creek using specialized stainless steel incubators. The eggs were supplied by the Goldstream River Hatchery over the past three years.
The first returns are expected “any day now,” Harris said Wednesday. “We have a lot of people out there looking. We don’t want to miss them.”
Harris said he was in the creek last week when he saw a fish, about a foot long, in the bottom, but he could not identify it as a salmon.
Bowker Creek is an eight-kilometre urban waterway flowing through Saanich, Victoria and Oak Bay and mostly hidden by underground culverts after more than a century of development. It started on its road to recovery in 2020 when a portion of the creek where it spills into the ocean near Oak Bay Marina was prepared for the return of chum salmon.
Salmon haven’t been seen since major diversions of the creek flow began in 1914.
Friends of Bowker Creek prepared the riparian areas of the creek near Monteith Street and were granted approval by the Department of Fisheries and Oceans for the placement of about 30,000 salmon eggs. About the same amount have been placed every year since then, though the design of the incubator boxes has been refined.
The creek once supported coho salmon and cutthroat trout, and First Nations middens of camp debris along its path have been found to date back 2,500 years.
Bowker begins in springs and underground gravel beds that collect winter rainfall on the University of Victoria campus. There is also an arm of the stream, near North Dairy Road on the Saanich-Victoria border, generated from springs at Cedar Hill Golf Course.
About 60 per cent of Bowker Creek is underground and flows through culverts, including under the parking lot at Hillside Shopping Centre, through Firefighter’s Park in Oak Bay and in other urban neighbourhoods.
The last chum salmon in the creek were documented around Royal Jubilee Hospital in 1914, which coincided with the building of the culvert system under Firefighters Park.
That’s about as far as any returning salmon would get at this point, said Harris.
The next placement of chum eggs is expected in January.
