Sixth-graders study Snoqualmie River water quality

October 7, 2009

By Laura Geggel

Every spawning season, pink salmon swim from the Pacific Ocean, through Puget Sound and up the Snohomish River to the Snoqualmie River.

From left, Snoqualmie Middle School sixth-graders Rylee Durham, Mariam McCandless and Maranda Clayton examine the Snoqualmie River’s water turbidity using a Secchi disc during a  fieldtrip at John MacDonald Tolt River Park. Photo by Laura Geggel

From left, Snoqualmie Middle School sixth-graders Rylee Durham, Mariam McCandless and Maranda Clayton examine the Snoqualmie River’s water turbidity using a Secchi disc during a fieldtrip at John MacDonald Tolt River Park. Photo by Laura Geggel

As the pink salmon, also known as humpies, struggled up the Snoqualmie past John MacDonald Tolt River Park, a group of sixth graders stared wide-eyed at them from the park’s suspension bridge.

But the Snoqualmie Middle School students didn’t have much time to gawk at the fish. Cara Ianni, education program manager for Stilly-Snohomish Fisheries Enhancement Task Force, started the students’ daylong fieldtrip with two workshops, one on the Snoqualmie River’s water quality and the other on forest plant diversity.

This is the second year the task force has funded the SMS fieldtrip, with help from King County and Washington State Department of Ecology grants.

SMS science teacher Gary Moen praised the fieldtrip’s hands-on applications.

“Sixth-grade curriculum studies diversity of life,” Moen said. “This is basically doing it in their backyard.”

Ianni told the sixth graders a myth from local American Indians about respecting salmon and asked the sixth graders to pretend they were salmon.

“I’m going to help you see the river through the eyes of the salmon,” Ianni said. “You’re going to see if people are respecting you. Would you return to the river?”

Next the sixth graders split into workgroups. One section walked to the Snoqualmie River’s bank to test its water.

“The salmon will come back whether it’s good water or not,” said Julie Nelson, an environmental educator for the non-profit Nature Vision, explaining the necessity of water meeting state ecological standards.

Poor water quality decreases the humpies chance of survival.

The group reviewed the pink salmon’s lifecycle — a lesson they had studied in elementary school. A female pink salmon lays between 1,000 and 2,000 eggs. Once they hatch, humpies embark on a two-year roundtrip journey to the Pacific Ocean before returning to their spawning grounds on the Snoqualmie River.

On average, only two salmon survive to complete the cycle.

With salmon on their minds, the students tested the water’s temperature and oxygen levels. Spawning salmon need cold water and a lot of oxygen, and the Snoqualmie River had both parts just right with 50 degrees Fahrenheit and 15 parts per million of oxygen.

Next up, the students measured the river water’s turbidity, or haziness.

Nelson filled tall cylinders with river water. The students dropped a disc with black and white markings, known as a Secchi disc, into the cylinder.

“Look straight down at the tube and stop the disk when it gets blurry,” Nelson instructed.

Sixth grader Chloe King peered down the thin tube, and announced she could still see disc at the cylinder’s bottom — the water was clear, a good sign for the salmon.

Salmon thrive in clearer water, especially if trees line the banks, protecting them from birds of prey.

“If you were a fish, would you want trees along the edge of the river?” Nelson asked.

“Yes, because they make oxygen,” Tess Davis said.

“Yes, because they prevent against erosion,” Ben Busick added.

The students got all shook up with the last experiment. They filled vials with river water and shook the samples with a chemical that changed color to indicate the phosphate level. Phosphates come from soap, fertilizer and pet waste and can harm a river’s ecosystem, threatening salmons’ survival.

Later that day, the group tested the water at another location in the river to make sure the data was consistent. Then, they learned about forest flora and fauna.

Sixth-grader Autumn Dukich said the fieldtrip tied in well with SMS’s watershed science unit.

In their next lab, students will study pre-dissected salmon and later plant trees along the Snoqualmie River to help salmon habitat.

Laura Geggel: 392-6434, ext. 221 or lgeggel@snovalleystar.com. Comment at www.snovalleystar.com.

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