Groundwater teaming with insects and amphibians fills the borrow pit where the Skeena River meets the Exstew River west of Terrace.
Northern Steelhead Society secretary Nathan Meakes steps waist-deep into the black speckled water dressed in waders and carrying a small net. He’s looking for signs of young salmon fry and smolt trapped here, in what’s become an annual summer exercise for the society over the last four years.
“It’s been a fish trap hazard for 40 years,” says Meakes.
The borrow pit stretches about 20 metres across, 50 metres long, and is at least a metre and a half deep. In the 1970s the Ministry of Transportation dug the hole for construction fill in the bridge spanning the Exstew River.
High river levels from the spring snowmelt usually breach the Exstew, creating a stream that flows into the borrow pit.
Young fish out-migrating to the ocean move into this area, eager to escape the fast-moving currents fueled by the spring run-off for a more tranquil place to hide. But when the river levels drop, so does their escape back to the river. Stranded throughout the summer, the smolts die as the water warms and becomes oxygen-deprived. Predators also find the smolt’s predicament an easy meal.
By late August, the pit is bone-dry.
“It’s created a fish trap for coho, cutthroat, chinook and steelhead smolt,” Meakes says. “It is a man-made impact that doesn’t need to be here.”
In partnership with the Department of Fisheries and Oceans, Steelhead Society volunteers go out to the pit with minnow traps then bait and place them in the water. The traps are pulled and rebaited the next day, and the fish are then put into buckets and taken to the Exstew River. Volunteers then spend two hours acclimating them to colder water temperatures before they’re released.
“We find anywhere between a couple smolts, to up to 40 to 50 smolts per trap,” Meakes says, estimating volunteers are able to save between 1,000 to 2,000 smolt and fry every year.
The number of young fish trapped in the pit can vary depending on how long it’s accessible to the river, but Troy Peters, Northern Steelhead Society branch chair, says if water levels remain high for a month there could be up to 10,000 smolt and fry trapped in a year.
Last year Peters estimates at least 5,000 were found in the pit.
“That would be about 50 adult fish coming back [to spawn],” Meakes adds. “That’s year after year, after year.”
Only 300 coho returned to spawn in 2018, highlighting the importance of those 50 lost fish, volunteers say.
“The first time we threw traps in here was in October, and in two traps we got close to 400 fish in a 12 hour set, which is an incredible amount of fish,” Peters says.
Ironically, before they could rescue the juvenile fish, the society had to prove the pit was killing them.
“What we had to do was let those fish go, and we’d come back in the spring after the snow had melted and the pit was dry. The bottom of the pit was littered with smolt and fry. It was shocking.”
‘Every fish matters’
While estimates are still coming in for salmon returns this year, the Tyee Test Fishery is reporting the retention rate of sockeye salmon is historically dismal — the worst in 10 years. At the time of this writing, 205,782 sockeye were counted. That’s way down from the 708,424 sockeye recorded last year, and far from the 800,000 threshold for a recreational Skeena sockeye fishery.
If these numbers for sockeye are any indication of what stocks look like for other salmon species this year, the need to maintain their chances of surviving to adulthood is paramount.
“[The borrow pit] is a huge impact, they have enough natural issues right now in terms of fish stocks and man-made problems. This is just one more gauntlet that these fish face,” Meakes says.
He says it’s estimated between just one to three per cent of fish survive to adulthood and return to spawn.
“Out of the 10,000 eggs that are spawned, maybe 5 come back as adult fish.”
“Every fish matters, every piece of habitat matters,” Peters adds.
The Ministry of Transportation is responsible for filling the pit. The project historically has been a low priority, but now the ministry is ready to act, says Daniel Baker, Skeena District Manager for the Ministry of Transportation.
“There was a whole bunch of commitments [in the area],” Baker says. “We basically made a mess there doing clearing and grubbing and things like that. There was the pit cleanup we had to do, there was the placement of some gravel in the boat launch, and a few other related clean-up [projects].”
That will change this summer. In August, the ministry will be filling the pit with 1,000 truckloads of gravel, which should take about four to five weeks to complete. The rock will be taken from another ministry pit located near the site.
“We’re doing all of those commitments at the same time they’re doing the Exstew borrow pit,” Baker says.
Originally, blast rock from the now-shelved $57 million vehicle overpass project spanning the CN Rail tracks west of Terrace was going to be used to fill the pit. But when that project was abandoned and the money reabsorbed by the federal government, the question of how the pit would be filled was left up in the air.
Baker says $300,000 was preserved to finance the clean-up.
“[The] borrow pit is being filled at this time because of the funding opportunity that was created when the larger project was being developed,” he says.
Meakes says he was happy to hear the news. River levels were so low this year the society won’t need to rescue any trapped smolt or fry, but filling the pit ensures the problem will not exist in the future.
“This is the perfect time to do it,” he says.