The Chinook salmon at Blind River Rapids were in no hurry to swim upstream. It was mid-July and they were hanging out in the clear, rocky water of the rapids, slowly preparing to spawn.
The popular freshwater sport fishery targeting Chinook salmon was forced to close earlier this year due to low expected yields, prompting operators to try an unconventional approach to help the fish.
Help came in the form of fish hatchery workers, biologists and volunteers who crowded the shore, waiting to help some Chinook salmon make the long journey home – on quad bikes.
“We finally got to the point where we thought we needed to try something,” said Bill Gass, the rapids’ manager and a member of the Southern Southeast Regional Aquaculture Association, an organization that manages the 50-year-old Crystal Lake fish hatchery and others in the region.
The plan was to scoop the fish out of the water, put them in containers, haul the containers to the ATV and drive it up the 1,500-foot boardwalk to the road where a larger container would be waiting. Once full, it would be trucked up the highway to the Crystal Lake Hatchery, where the salmon would “age” for several weeks before spawning.
That was the plan. It would be the first time they tried it.
They had decided to try it because the fish farm needs a certain number of returning salmon each year to create the next schools of Chinook salmon. These returning salmon are known in the industry as farmed salmon. The fish farm had failed to meet its breeding goals in two of the last ten years. This year, expected yields are low.
Gass said management discussed the possibility of transporting the salmon for decades, but the experiment was risky. The fish become stressed when handled the way they are when caught and then transported from tank to tank. This stress could affect the viability of their eggs or even kill them.
So why can’t the fish get to the fish farm on their own? According to Gass, it’s an unusual place.
“That’s all these fish can do to stay alive,” he said. “The last section is really difficult, it’s often six inches deep. So they sit there, cooking and fighting.”
The salmon must swim up a tidal marsh that becomes rapids in places. It is shallow and rocky, especially when there is little rain or the tide is low. This makes it difficult for the salmon to swim through, which means the marsh heats up quickly. Chinook salmon do not tolerate heat well. According to state biologist Patrick Fowler, they can tolerate heat for a while.
“Then there is the red line: When it gets warm and we have a lot of fish in a small space, but not much water comes – that is often the reason why they die,” he said.
Chinook salmon usually stay in the rapids for several weeks. If it rains and the tide is high during this time, the salmon have a good chance of making it to the hatchery. However, some years the tide is low and the weather is warm, and the Blind River Rapids are littered with rotting salmon carcasses. While this is good for the feeding eagles and bears, it makes it difficult for the hatchery to meet its breeding goals.
So is this problem due to climate change? Fowler said there isn’t enough data to say.
“We don’t have good temperature records, you know, that go back long enough to know that, specifically for Blind Slough,” he said. “We know that there were mass extinctions in Blind Slough decades ago.”
He said that while it is not a new problem, warmer water in the marsh will exacerbate the problem.
“I don’t think the problem will get better in the future! I would probably put it that way,” he said.
Rick Fritsch of the National Weather Service says higher air temperatures are an indicator of warmer water. He said the data strongly suggests that 15 miles north in Petersburg, average July temperatures have risen significantly in the 50 years since the fish hatchery was built.
At the Blind River Rapids, Fowler helped organize volunteers, standing on the bank with containers of nets and buoys nearby.
“Who here has waders that want to go into the water?” he asked.
Six people raised their hands.
He outlined the plan.
“So we have two 300-foot nets,” he said. “The idea is we’re going to put this one basically downstream, from here to this point on land, to prevent them from running down.”
Some volunteers waded into waist-deep water, dragging the net behind them. Other volunteers ventured upstream with the second net and drove the fish into the depths. The trapped fish were easily fished out with a landing net and then driven one by one to a holding basin in the shallows.
From there they were brought ashore – very carefully – to a carrying bag on wheels, which was pulled to the waiting quad as soon as it contained two or three fish.
To avoid crowds, the kings were slowly driven up the promenade.
At the highway, volunteers helped tip the fish into a larger container. When it had a capacity of about a dozen fish, it was transported by truck several kilometers to the fish farm.
Gass peered into the depths of the assembly point.
“So they’re still swimming?” he asked.
“Oh, they’re doing great now,” the volunteer told him.
“Oh good, that’s what I was hoping to see!” he said with a grin.
By the afternoon of the same day, the team had brought 64 fish into the hatchery and not a single one had died. The next week, they repeated the process again. This time, they brought 82 fish into the hatchery and there was one death. They had planned a third day, but a flood was coming and heavy rain was forecast, so they decided to give up.
Although they were still more than 1,000 fish short of making it to fish farming using traditional methods, Gass said he was quite satisfied.
Still, I had to ask: “Why is all this effort worth it?!”
Gass laughed.
“People love their Chinook salmon,” he said. “And you know, that’s the only way to keep the operation going. We need eggs. We need to get these fish to the hatchery.”
The project was a test of concept, he said. Now they will track the eggs of the transported salmon to see how successful they are and what the survival rate is.
Gass said they would know more in mid-August when fish farmers begin the spawning process – which involves fertilizing fish eggs by hand.
