Harvest, hatchery, habitat: Bringing chinook back from the brink

Mike Youds, June 18, 2020

Lindsey Tatoosh holds aloft a chinook salmon while taking eggs in fall 2018 at Robertson Creek Hatchery. Marking of hatchery chinook is used to gain a better understanding of wild chinook once they leave freshwater. (Mike Youds photo)

This is thhe second in a series of Ha-Shilth-Sa articles on wild salmon harvest, hatcheries and habitat.

Fisheries and Oceans Canada wants a comprehensive rebuilding plan ready within a year’s time for chinook salmon on the west coast of Vancouver Island, and says NTC could play a lead role in the process.

A fresh opportunity to rescue dwindling stocks of the largest, most prized and most threatened of Pacific salmon species arrives in fall through amendments to the federal Fisheries Act.

After years of declining numbers, a “fish stock” designation under the act will automatically require implementation of a rebuilding plan within two years, DFO’s Rebecca Reid, Pacific Region director, wrote in a recent letter to the Council of Ha’wiih Forum on Fisheries.

Reid said the department will consider a combination of harvest, hatchery, and habitat-related strategies to foster the rebuilding of depleted chinook stocks, including consideration of the efficacy of mass marking and mark-selective fisheries in collaboration with First Nations, the provincial government, commercial and recreational harvesters, and environmental non-governmental organizations.

The rebuilding initiative stems from legislation restoring fish habitat protections removed by the Harper Conservative government, said Wilf Luedke, chief biologist with DFO’s south coast area stock assessment branch in Nanaimo. Among amendments is one that makes a rebuilding plan mandatory when stocks hit a low point. West coast Vancouver Island chinook have been chosen to pilot the new legislation, he said.

“There is some rebuilding funding now to start the process,” Luedke said. A first step is to form a steering committee of DFO, NTC and other groups. The plan is supposed to be completed by March 2021, he said.

“What we’re looking for is a lead,” he said, suggesting NTC could step up.

Habitat damage from decades of logging and overfishing are often blamed for declines in wild salmon populations, but Luedke believes there is no single, smoking gun in the case of west coast chinook. Even in relatively intact watersheds, such as those of the Megin and Moyeha rivers in the Clayoquot Sound region, chinook survival rates have plummeted, he noted, adding that he can understand the depth of frustration among First Nations.

“If you’re Ahousaht trying to get fish out of the Megin River, you can’t,” he said.

Luedke blames warming ocean conditions, specifically a string of back-to-back El Nino warm-water years that brought a steady decline of wild chinook starting in the 1990s. Mackerel migrated north from California and decimated small chinook fry at one point. Chinook stocks that once had ocean survival rates of five to 15 per cent 30 years ago have plummeted to 0.5 to five percent.

“The ocean’s just not the same place anymore,” he said, alluding to a general decline in productivity. “If we get to one or two percent (marine survival), then we’re out of the woods.”

U.S. research suggests an integrated approach — the “three Hs,” a combination of fish habitat restoration, hatchery production and stricter harvest management through mark-selective fisheries — to be the best approach, he said.

“We’re looking at things like mass marking at Conuma (hatchery),” Luedke said. “Could we just catch hatchery fish? Every hatchery fish could be clipped.”

Juveniles studied

A lot of scientific research has already been done on 15 west coast watersheds, such as the Sarita, Bedwell, Tranquil and Burman. Luedke took note of scientific groundwork by Huu-ay-aht First Nations as well as by Uu-a-thluk biologist Jared Dick to the north. Could traditional Nuu-chah-nulth knowledge, combined with new understanding from research, blaze a path back to health for west coast wild chinook?

Focused on answering critical questions about juvenile chinook growth and survival, Dick has made some revealing findings.

“What we’re finding with small coastal streams chinook are coming out at a half gram, a really small size of fry,” he said.

Some are so under-developed they haven’t absorbed their yolk sacs from the alevin stage. That could contribute to higher mortality because smaller fry are less resilient in response to stressful events.

That’s why hatcheries are studying release of larger fish of five to 10 grams, Dick said.
Young chinook rely on estuary health for shelter and nourishment before migrating to sea, habitat often affected by logging activity and resulting silt deposits along the west coast.

“If freshwater habitat is so degraded, you always want to keep estuary habitat as healthy as possible to protect the growth of juveniles,” Dick said.

Fry could be arriving in the estuaries too early in the year, he suggests. In a warmer climate, thermal signals that tell the egg when to hatch could be occurring too early in the season. Are they arriving in estuaries too soon to benefit fully from the spring flourish of zooplankton and insects?

Another aspect of his research investigates whether chinook decline is related to sea lice, which spiked last summer at several Clayoquot Sound fish farms, forcing temporary closures. Smaller, less developed juveniles would be more vulnerable to sea lice. If that were the case, a higher density of fish farms in certain areas could have a compounding effect.

“Let’s look at the pathogens juvenile salmon have after they swim past the river, the estuary, and after the fish farm,” Dick said.

The central region biologist also pointed to research at Nitinat River Hatchery in Ditidaht territory to improve juvenile survival. They’ve been raising hatchery smolts in conditions closer to natural habitat and varying the diet to include zooplankton in order to train them for marine habitation.

A three-year pilot project at Conuma hatchery — mass marking all hatchery produced chinook — was set to begin this spring but the COVID-19 pandemic has delayed that research for a year.

Hatchery pros and cons

The federal government’s floating of a chinook rebuilding plan wasn’t news to Andrew Jackson, Tla-o-qui-aht fisheries manager, who has discussed the idea with DFO staff. He’s heard of too many plans in his 29 years on the job to feel confidence in this one.

“We need a production plan” for the whole region, he said, taking stock of existing salmon hatchery facilities. There are two major hatcheries in the south, at Robertson Creek and Nitinat, and one up north at Conuma. Small hatcheries are situated in Tofino and at Kennedy River in Clayoquot Sound.

“We’re the only region without a major hatchery,” Jackson said. “No wonder we’re the region with no fish.”

While the status quo is not working for chinook, he also believes hatchery production is an essential rebuilding tool if used carefully.

“There have been pros and cons,” Jackson said.

Smaller chinook caught nowadays is a trend he attributes to hatcheries diluting the gene pool. Tla-o-qui-aht used to capture brood stock for the Kennedy River hatchery that ranged from 70 to 90 pounds; now they’re more likely to be in the 30-pound range.

“Without hatcheries, there would be a lot of stocks extirpated by now,” he said. “Genetically, we’ve altered the makeup.”

He sees lots of opportunity to restore habitat in the Tranquil and Kennedy basins, to name just two watersheds while the production of hatchery chinook could help rebuild Nuu-chah-nulth fisheries, taking the pressure off tightly managed wild chinook. He, too, sees harvest management as part of the rebuilding equation.

“You can’t have ongoing fishing in a stock you’re trying to rebuild … It’s just too much of a small stock out there. That’s why we’re in trouble. Why not just leave it?”

Jackson suggested the west coast recreational fishery could be temporarily diverted to terminal fisheries, held in or near spawning rivers, as another means of closely managing wild stocks.

But first they need to “sit down and talk about recreational fishing,” which takes the biggest share of west coast chinook.

“They definitely need to work with us,” he said. “We never said we want it all. We want to look after it.”

Disputes over fishery allocation have long hindered co-operation needed to protect wild salmon.

“Salmon fisheries, salmon resources are usually conflicted and B.C.’s have been for more than 100 years,” said Eric Angel, Uu-a-thluk program manager. “Fisheries are always tough to deal with in terms of allocation because it’s like everyone wants a piece of it and the government places itself in the position of deciding that.”

That’s why he wants to see a sea change, a transformative approach to salmon that recognizes their extraordinary role as a keystone species integral to the ecosystem rather than simply as a commodity for trade and consumption.

In other words, don’t get hung up on allocation.

Luedke said details need to be worked out for the chinook rebuilding plan and expects a busy schedule of workshops ahead over the next six months.

“I think ‘harvest’ has a bunch of pieces to it,” he offered, speculating on the thorniest of issues. “Is there sorting going on in the fishery? Do we need a cultural change in fishing to let the big ones go? There’s a lot of tools we could bring in that we need to explore.”