Snake River fall chinook make a comeback

BY ROCKY BARKER

May 12, 2014 

  • Idaho's salmon and steelhead

    All salmon and steelhead are born in freshwater and migrate to the ocean. The stocks in Idaho are:

    Sockeye, the red fish that gives the famed Idaho lake its name. They have the distinctive jutting lower jaw. They are born in streams but grow up in lakes and stay longer than other salmon - up to three years - before migrating to the sea. In 1992, a single sockeye nicknamed Lonesome Larry returned to Central Idaho's Redfish Lake, a tale that galvanized public opinion over the dire condition of the Columbia-Snake salmon runs.

    Chinook, the biggest salmon, also called king salmon. Fall chinook are a subspecies that migrate and spawn in the fall. Spring-summer chinook migrate and spawn earlier in the year.

    Steelhead, large rainbow trout that, unlike their smaller cousins, migrate to the sea before returning to their native streams to spawn. Unlike salmon, which die after spawning, steelhead can migrate and spawn multiple times.

    All are listed as threatened or endangered species.

The fate of the Snake River fall chinook salmon has not garnered the attention of its more famous cousin, the sockeye.

But the comeback of the giant salmon that once spawned as far east as Shoshone Falls and the Boise River has been even more robust than the sockeye's.

The fish were nearly sent into extinction by the building of Idaho Power's Hells Canyon dams in the 1950s and '60s, which closed off at least 80 percent of the streams that made up chinook spawning habitat. The comeback effort - which included Idaho Power, the Nez Perce tribe, state and federal officials, and the Bonneville Power Administration - accounted for a total return of 75,846 wild and hatchery-born fall chinook at Lower Granite Dam on the Snake in 2013.

Of that figure, more than 20,000 were wild, or native, chinook; in 1990, just 78 wild fall chinook were counted at Lower Granite.

"Keep in mind we are at about 15 percent of historic habitat," said Nez Perce research director Jay Hesse.

The Nez Perce, whose people depend on the fall chinook caught in the Columbia River and in Idaho waters, has aggressively pushed to supplement wild fish populations with hatchery salmon propagated from native fish. This practice - used for all of the endangered salmon and steelhead in the Columbia - has been especially successful for Snake River fall chinook.

But it didn't come easy. Conservation efforts began in the 1980s when the Lyons Ferry hatchery was built in Washington state and native Snake River fish were trapped to provide stock. Idaho Power paid to release 1 million smolt into the Snake at Hells Canyon.

Meanwhile, returning wild chinook found troubled waters in Hells Canyon. Idaho Power raised and lowered the river each day as power demand rose or fell, often uncovering the salmon's gravel nests, known as redds. In 1991, even before the fish were added to the endangered list, Idaho Power announced that it would stabilize flows in the fall to protect the redds.

The utility expanded that to the spring as its biologists saw the benefits of stable flows for rearing chinook.

"As we've gone through that program, we've started to modify our operations to protect juvenile fish," said Chris Randolph, Idaho Power's environmental program manager.

A HATCHERY BOOST

The breakthrough came in 1995, when federal officials were going to end tribal fishing on the Columbia River of the more abundant fall chinook that spawn in south-central Washington's Hanford Reach to protect Snake River chinook projected to return to Idaho.

Both sides were ready to go to court until a federal judge warned them that neither would be happy with his decision. Instead, they negotiated.

"This program was born in anger and frustration," said David Johnson, Nez Perce tribal fisheries program manager.

The two sides reached an agreement that limited the harvest that year in exchange for allowing the Nez Perce and other Columbia River tribes to release young Lyons Ferry chinook into the rivers above Lower Granite Dam, including the Clearwater River.

In 2003, using funds from the BPA, the tribe completed a modern hatchery on the Clearwater. That boosted the number of Snake River fall chinook smolts produced in hatcheries to 5.5 million, today's figure.

HABITAT AT HATCHERIES

The wild fish's genetic characteristics are important to its survival. To preserve those characteristics, biologists are careful not to overwhelm the wild populations with hatchery fish. The hatcheries also operate differently today, providing runways into the facilities that are more like the wild habitat with brush, logs and other cover.

Improved habitat created by stabilized flows, the tribes' supplemental fish and generally improved conditions in the Pacific have allowed the chinook to thrive.

"In 1990 we had 47 redds," said Jeff Allen, an Idaho staffer with the Northwest Power and Conservation Council, which recommends where BPA should invest salmon dollars. "Last year we had 6,000."

The 20,222 naturally spawning fall chinook that returned in 2013 and the 27,000 expected this year far exceed the initial target of 3,000 that federal fisheries officials set as a recovery goal. Officials now are working on a target based not just on numbers, but also on productivity and genetic diversity.

Eventually, the Nez Perce and others hope to find a way to return the fall chinook to its historic Snake River habitat in Idaho above Hells Canyon. But water quality and other river conditions make trying expensive dam-bypass systems unrealistic, officials say.

Fall chinook are the only one of the stocks of endangered Idaho salmon and steelhead that are at or near recovery targets, but returns this year for all species are expected to be the sixth-highest since the Columbia River dams were built in the 1930s. About 125,000 spring-summer chinook are expected to pass Lower Granite, just northwest of Lewiston.

CHANGING TO SURVIVE

Scientists, meanwhile, are observing behavior that suggests the Snake River fall chinook are adapting to their environment. Usually, fall chinook hatch in the spring. The smolts, just inches long, enter the ocean a few months later.

But as many as a fourth of these chinook are staying put in the river for at least a year - either at the mouth of the Clearwater or downstream in the Columbia - before heading to sea.

The chinook that delay their migration are about eight times more likely to make it back to their spawning grounds than are the traditional migrating chinook.

These fish, like the managers who have worked to save them, are learning to live in the new world.

"This is a testament of dealing with the cards we've been dealt," Johnson said.

Rocky Barker: 377-6484

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