The dye is cast to learn about a river's "fever"

James Kardouni's fingers were stained bright pink when it was over.

In long boots and a life jacket, the environmental specialist had waded into the tree-lined Snoqualmie River at Fall City on Tuesday morning and dumped two bottles of dark liquid dye into the water.

"Putting dye in the river is kind of scary even though it's benign," Kardouni said about the nontoxic Rhodamine dye.

The dye is necessary to help determine why the river's water is warmer than scientists had expected. And Kardouni was at Fall City as part of a state Department of Ecology study of the river's watershed to figure it out.

The river's temperature — about 73 degrees Fahrenheit and higher in some spots — is well above the state standard of about 64 degrees for this time of year.

And while the empty beer cans scattered along the river bank in Fall City indicate that the water temperature is comfortable enough for humans to relax, scientists say it could be a problem for the salmon and trout there, which need cool water.

The dye Kardouni released hit the water as a ribbon of fluorescent pink and quickly transformed into a strikingly dark orange, passing a bridge where cars rumbled above.

The plan was to track the dye when it passed a sensor seven miles downstream and again at six miles farther along to measure the speed the water flowed.

This information can provide a key to understanding why the water temperatures are higher than expected. If water is shallow and slow, for instance, the water can be more easily warmed during the day, said Larry Altose, a spokesman for the northwest region of the Department of Ecology.

The Fall City spot is one of five locations on the Snoqualmie River where the state Department of Ecology is scheduled to release dye, which can stain skin and clothing, this week.

The dye tests are part of the department's temperature study of the Snoqualmie River watershed, which scientists hope will help preserve the chinook salmon and bull trout — both listed as threatened under the Endangered Species Act — as well as other fish there.

The goal of the study: Figure out why the river temperatures are higher than standard, where these temperatures are simply a natural result of the river's width and low flow, and where the river can be cooled down.

The research started this past January after higher-than-standard temperatures in the river were detected between 2001 and 2005, said Ralph Svrjcek, a water-cleanup specialist for the Department of Ecology.

The causes could be anything from the river's width to a lack of shade-giving trees because of farming and other development nearby, Svrjcek said.

Higher than standard temperatures can be dangerous for fish.

They can cause oxygen levels in the water to decrease and fish metabolisms to speed up, said Pat Frazier, a program manager at the state Department of Fish and Wildlife.

With limited food supplies, fish become weak, making them more susceptible to disease, which grows more quickly in warm climates, he said.

And high water temperatures can reduce the ability of juvenile fish to reproduce later in life, said Yvette Lizee-Smith, watershed coordinator for the Snoqualmie Watershed Forum.

"A healthy stream in the Pacific Northwest is a cool stream," Svrjcek said. Temperatures higher than the standard is similar to the river running a fever, he said.

Fieldwork this summer includes sensors that have constantly monitored the temperature of the river and some of its tributaries at about 45 different spots.

In addition, scientists have periodically measured the speed and depth of the water flow at most of these locations through dye tests and other methods. This week's flow tests are the second of three sessions, with the last session scheduled for the week of Sept. 11.

Scientists have also been gathering data on the trees and other vegetation near the river.

Research results are scheduled to be publicly released at the end of 2007, according to Svrjcek.

The best tool against the high temperatures could simply be planting more trees to increase shade, he said. It's like "giving the stream a beach umbrella to stay cool."

"If we're creating a good environment for fish, then we're creating a good environment for all organisms that naturally flourish in streams," Svrjcek said.

Other streams in the Puget Sound area — including the Green and Samish rivers, Bear and Evans creeks and the Old Stillaguamish Channel — also are being investigated for water-temperature issues, Svrjcek said.

Anne Kim: 206-464-2591 or akim@seattletimes.com