Monster December Storm Likely Harmed Future Olympic Peninsula Chinook Returns

FORKS (Dec. 19, 2007) — Chinook returns to Olympic coastal rivers — already down significantly from recent years — took another hit from early December’s monster storm.

“Right before the storm, we had active spawning in throughout the Quillayute River system , and the kind of flows we saw with this storm will certainly reduce egg survival because the high water scoured eggs out of the gravel,” said Roger Lien, fisheries biologist for Quileute Tribe.

Average flows this time of year on the Olympic Peninsula’s Hoh River are about 3,000 cubic feet per second (cfs). Flows of more than 60,000 cfs were recorded during the Dec. 3 storm.

“That storm hit two weeks after peak fall chinook spawning on the Hoh,” said Tyler Jurasin, fisheries biologist for the Hoh Tribe. “Most of the eggs were in the gravel. Fortunately, salmon produce a lot of eggs and that trait helps chinook survive flood events. However, the frequency and severity of these floods continues to increase and we’re concerned about how that affects survival.”

Flooding also occurred in late October 2003, diminishing egg survival of our spring/summer chinook that spawn from mid-August through mid-October,” said Jurasin. “We considered that event when forecasting the 2007 return of spring/summer chinook. Four-year-old chinook from the 2003 brood returned at the low numbers we predicted.

“Severe flooding also occurred in early November, 2006,” said Jurasin. “The timing of that storm could reduce both spring and fall chinook egg survival. The back-to-back flooding of last year and this year poses a greater risk to future recruitment because consecutive broods were harmed that will produce returns in overlapping years.” The majority of chinook return as 4 and 5- year-olds.

Earlier this year, summer chinook returns to the Sol Duc River were low. “We forecast a low return this year and that was pretty much the case for summer chinook on the Sol Duc,” said Lien. In early December, the Quileute Tribe was still conducting fall chinook spawning surveys on the Sol Duc, Bogachiel, Calawah, and Dickey Rivers. “We’re seeing some late spawning activity, but these runs were also expected to be lower,” said Lien.


For more information, contact: Roger Lien, fisheries biologist, Quileute Tribe, (360) 374-2478; Tyler Jurasin, fisheries manager and biologist, Hoh Tribe, (360)374-6737; Debbie Preston, coastal information officer, Northwest Indian Fisheries Commisson, coastal information officer, (360) 374 -5501, [email protected]