The number of pink salmon -- called humpback or humpies because spawning males develop humped backs -- surging up the Columbia River this late summer is small, in a relative sense, yet huge in a historical sense.
At a time when thousands of fall chinook and coho salmon and steelhead are moving upriver each day, a total of 1,806 of the “pinks” have been counted so far this year passing up and over Bonneville Dam, some 146 river miles from mouth of the Columbia at the Pacific Ocean.
That total could grow much bigger, since passage remains strong. Wednesday’s count at Bonneville was 155. Few of the pink salmon have been accounted for upriver, though a single fish has made it as far as Little Goose Dam on the lower Snake River in southeast Washington. That’s 70 river miles upstream from the confluence with the Columbia.
“Every day is a record,” the Washington Department of Fish and Wildlife’s Joe Hymer said of the pink salmon counts at Bonneville.
That fact in itself is an oddity for pink salmon, which in northwest Washington, British Columbia, Alaska and elsewhere around the Pacific Rim tend to spawn nearer a freshwater-saltwater nexus. Pink young forsake freshwater rearing, choosing instead to swim toward the ocean almost immediately after they emerge from their eggs.
The previous high count, on a record dating back to 1938, at Bonneville’s fish ladders was 637 in 2003. There have been only seven annual counts on that record of more than 100. Already this year there have been seven daily counts of more than 100 pink salmon at Bonneville Dam.
Primary spawning populations occur from the Puyallup River in Washington northward to Alaska. And while pink salmon have been counted during spawning surveys in lower Columbia River tributaries such as southwest Washington’s Cowlitz River, there is no known sustained pink spawning population in the Columbia River basin.
“It is an interesting part of the job when these sorts of curiosities happen, especially when they don't seem to be doing any harm,” said Stuart Ellis, a biologist with the Columbia River Inter-Tribal Fish Commission. Nez Perce, Umatilla, Warm Springs and Yakama tribal fishermen have caught a dozen or more pink salmon this year in commercial fisheries above Bonneville and that is unusual.
“Some of the fishers have said they were going to keep them and smoke them or eat them just for the novelty. A few have been sold to the buyers,” Ellis said.
Likewise pinks are being caught in the lower White Salmon River, which feeds into the Bonneville pool, according to Rod Engle of the U.S. Fish and Wildlife Service. The USFWS and Washington Department of Fish and Wildlife are working there to capture fall chinook before they spawn. Those fish will be transported above Condit Dam and released so that they can spawn upriver. Condit Dam is scheduled to be breached in late October, which will result in a downstream rush of sediment that would choke spawning beds.
Ellis theorized that the big pulse of pinks, as compared to the past, could be a unique merging of natural forces. Perhaps some of the fish could be strays from the Puget Sound, where a bumper crop of pinks was expected to return this late summer and fall. And/or some of the returning pinks could be returns from Columbia River basin spawning events that benefited from favorable ocean conditions.
“The number in the Columbia this year might be because of good ocean survival,” Ellis said. “There may be some factors like currents/temperature/ and food sources that just brought the run farther south this year which could have increased the straying into the Columbia.”
He acknowledged, however, that “most of this is just guesswork. Nobody I have spoken too has much of any real data to base anything on.” The existence of pink salmon, unlike other salmon species, is little studied in the Columbia basin because they have not, at least in modern times, had any sort of a footprint.
“We’ll know more when we start walking the rivers,” Hymer said of spawning ground surveys that will begin in the coming weeks that are designed to assess the status of wild tule fall chinook salmon in lower Columbia River tributaries. Pinks in the past have been identified in small numbers in or near the mouths of such rivers at the Toutle, Grays, Kalama, Cowlitz and Wind rivers.
Hymer said he would be curious to see genetic analysis of the pink salmon now exploring the Columbia to see how they compare with, as an example, Puget Sound populations. But he was not aware of any such plans.
“It would be a great year to do that” given the relatively high incidence of pinks in the Columbia, he said. Genetic analysis could potentially tell whether the fish are recent strays from northern populations, or are more distinct populations that have a more localized history.
“Usually there are just a few here and there” but, given the high numbers at Bonneville, Hymer said he suspected there are quite a few pinks in those lower Columbia River tributaries.
Pink salmon are known to seize on opportunities to colonize suitable habitat, such as in the Puget Sound’s Green River, Hymer said. The population there grew there from near zero to returns in excess of 2 million.
Nearly six million pink salmon overall were predicted to return to Puget Sound this year. That forecast is 3 million salmon below 2009’s record return but still an abundant run.
And the return just north of the border to British Columbia’s Fraser River was expected to total 17 million.
The pink salmon are the smallest of the Pacific salmon, averaging from 3 to 5 pounds, but also the most abundant. They can be found in spawning streams all around the Pacific Rim, including as far south as northern Japan. In North America, pink salmon populations regularly occur in marine waters as far south as northwest Washington state in streams that feed into Puget Sound and in the Olympic Peninsula.
* Idaho Power Begins Operations To Get Ready For Fall Chinook Spawners In Hells Canyon
With inflows expected to be higher than normal this year, the Idaho Power Company has begun a steep draft of the Hells Canyon Complex’s Brownlee Reservoir to set the stage for operations this fall and winter to protect what has become a growing annual community of salmon “redds.”
After Labor Day weekend, Idaho Power began drawing down the reservoir in preparation for its Fall Chinook Program which provides flat flows for salmon spawning in the Snake River below Hells Canyon Dam. Outflows in recent days have risen to more than 20,000 cubic feet per second after simmering in the teens for most of August.
Brownlee Reservoir – the primary “storage” project among Complex’s three dams on the Idaho-Oregon border -- elevation will continue to drop through the month of September. As of Monday the reservoir level was 2,047 feet, leaving the boat ramps at Hewitt and Woodhead parks the only usable ramps on Brownlee. The water level will drop below Hewitt’s boat ramp by this weekend.
The company anticipates all boat ramps will be out of the water during October. The water level is expected to fall to approximately 2,015 feet by the end of the month. To maintain flat flows during fall chinook spawning, Oct. 10 through Dec. 5, space must be made in Brownlee Reservoir prior. As the spawning period begins, the reservoir will begin to refill.
For updated Snake River flow and Brownlee elevation and boat ramp information, please visit http://www.idahopower.com/OurEnvironment/WaterInformation/default.cfm
The company anticipates the minimum flow set during the spawning period can be maintained until fry emergence (when the young fish leave the redds, or nests) in the spring without emptying Brownlee Reservoir.
The number of fall chinook salmon redds counted each year from Hells Canyon Dam, which blocks fish passage, down to Asotin, Wash., has been rapidly rising, particularly over the past decade. The count was 346 in 2000. The Snake River redd count last year totaled 2,944, which was the most since counts began in 1988.
The 2010 fall chinook return, as measured at Lower Granite Dam, streaming into the Snake and tributaries such as the Clearwater was 41,815, which more than doubled the previous high count of 16,624 in 2008. Lower Granite is located on the lower Snake River in eastern Washington downstream of Hells Canyon.
Many of the spawners are of natural origin. Some are fish acclimated by the Nez Perce Tribe at Pittsburg Landing, Captain Johns Landing and Big Canyon before their release. Still others are fin-clipped hatchery fish released below Hells Canyon Dam by Idaho Power.
This year’s return looks strong. A total of 8,510 adult fall chinook had been counted at Lower Granite through Wednesday. The run appears to be at its peak with a high count of 1,063 on Monday, followed by 656 Tuesday and 830 Wednesday.