Thompson River Steelhead — The River (Pt. 1)

Graveyard Pool on British Columbia’s Thompson River. Photograph from Steelhead Fly Fishing (1991) by Trey Combs.

Part I — The River

Why the world’s strongest steelhead are disappearing from British Columbia’s most famous river.

Few steelhead runs in the world have achieved the near-mythic status of the Thompson River steelhead of British Columbia. These enormous, powerful steelhead have fascinated anglers and biologists for decades. Yet despite their fame, their decline remains poorly understood.

In this three-part series, Trey Combs explores the river, the fisheries, and the vast North Pacific migration routes that shape the fate of the Thompson’s legendary steelhead.

British Columbia’s Fraser River, Canada’s largest free-flowing river, drains the interior of the huge province, an area more than half the size of California. Among the hundreds of named waters that source the Fraser, none are larger or more boisterous than the Thompson, a grand, clear-flowing desert river seventy miles long with two main branches, the North Fork and the South Fork. The two rivers join east of Kamloops to form Kamloops Lake, warm water that moderates the Thompson, both its seasonal flow and its temperature.

The Thompson’s South Fork marks the start of a perfect hop-scotch system of rivers–lakes–rivers complex necessary to support the life cycle of sockeye salmon. The South Fork’s source, Little Shuswap Lake, has in turn the Little River and Shuswap Lake as sources. But the heart of the system, the Adams River, a relatively short river connecting Shuswap Lake to Adams Lake, supports the greatest run of sockeye salmon in the world.

The first sockeye enter the Fraser in mid-August, and despite intense harvests by Canadian and American gillnetters, millions survive to begin racing toward Shuswap Lake, a migratory spectacle joined by a few hundred Thompson River steelhead. Both are national treasures, one for its economic value—a potential retail worth more than a billion dollars to the Province—the other famously revered by fishers for its extremely rare race of steelhead that are among the very largest on earth.

They may also be the strongest of all steelhead, not just a subjective claim made by fly fishers who have been spooled by Thompson rockets, but one supported in a classic scientific study that determined that the muscle tissue of these steelhead contains super-high concentrations of the enzyme lactate dehydrogenase. This enzyme provides the race with unique levels of endurance. In one study, Thompson steelhead were shown to have 3.8 times the stamina of Vedder River steelhead of equal size.

Millions of pink salmon migrate up the Fraser during odd-numbered years. Some spawn in the Thompson, but most will spawn in the Fraser. These fish are a valuable food fish whether canned—“pink salmon”—or sold fresh when caught as an ocean fish. They deteriorate rapidly on their spawning migration and are caught mostly as a recreational game fish or harvested for their roe.

The Fraser River’s chum salmon, the magnificent high-seas “silverbrights,” have always conflicted with efforts to safeguard Thompson steelhead. Their spawning migration perfectly masks steelhead returns in October and November. The chums deteriorate rapidly in freshwater as hormones transform the fish from ocean predator to spawning organism.

Often the dramatic color change males undergo—a vivid purple splotching—begins in saltwater. Equally dramatic, the male’s jaw becomes hooked and ends with long canine-like teeth, an appearance that has given the species the name “dog salmon.” As these physical changes take place, the chum’s flesh ultimately deteriorates so completely that their marginal value as cat food is not worth the labor of harvesting.

But it is at this very time that the female chum salmon can be harvested for their roe, a most valuable product that will be shipped, fresh or canned, to restaurants—mostly sushi restaurants—all over the world. The carcasses of the chums, the remains of the females, and the males also caught in the gillnets are dumped back into the Fraser to provide nutrients for young salmon and steelhead.

This industry is a notable success story for nearly a dozen bands of indigenous peoples, and the reason why the few Thompson steelhead left that do not survive the nets set for chum salmon are unable to gain protection under SARA, Canada’s Species At Risk Act. The Thompson steelhead surviving the Fraser’s chum gillnet fishery reach the Thompson in relative safety from anglers because the river is closed to fishing and has been for years.

The Thompson steelhead must still survive an aboriginal fishery that is little managed, poorly documented, and with no licensing requirements. Cooks’ Ferry Indian Band engage in “pitch lamp” fishing whereby a fire basket of burning pitch hangs from a boat and illuminates the river shallows. A man stands on each side of the boat with a spear while a paddler moves them along to hunt for the steelhead that sluggishly move about in the icy currents. They spear “chothleh” as a subsistence fishery, one that is now largely ceremonial. Nevertheless, this annually takes place, and steelhead are killed in this manner.

Also, any steelhead killed by a First Nation person will not be contested in the courts regardless of whether the Native is part of a tribal band with federally granted fishing rights for taking the wealth of salmon riches in the Fraser.

This Essay Is Part of a Series
Essay: Thompson River Steelhead — The River (Pt. 1)
Essay: Thompson River Steelhead — The Fisheries (Pt. 2)
Essay: Thompson River Steelhead — The Ocean Migration (Pt. 3)

Essay — Trey Combs
Trey Combs is the author of The Steelhead Trout, Fishing the High Country, Steelhead Fly Fishing and Flies, Steelhead Fly Fishing, Bluewater Fly Fishing, and Flies for Atlantic Salmon & Steelhead

Trey Combs (left) with legendary steelheader Harry Lemire and a typical Thompson River buck. Photograph from Steelhead Fly Fishing (1991) by Trey Combs.