Woodward Middle Schoolers test water quality on the island, to get the big picture.

With focus and concentration, three seventh-grade girls count drops of sodium thiosulfate into a vial of yellow liquid, swishing it around as it turns clear.

Rushing behind the rubber-gloved and rain-slickered trio is the object of their study, the cold waters of Manzanita Creek.

The girls count 10 drops, indicating 10 mg of dissolved oxygen per liter of water in the stream.

“That’s a good, healthy stream,” said Steve Morse, city planner assisting the Woodward Middle School students as part of World Water Monitoring Day. Fish need 8-9 mg oxygen per liter to survive, Morse says; at 6 mg per liter, they begin to die off.

Besides dissolved oxygen, students also measured water temperature, pH (measuring acidity) and turbidity – the clarity of the water. Tests were done at four salmon streams: Hidden Cove Creek, Issei Creek, Cooper Creek and Woodward Creek behind the school.

As part of World Water Monitoring Day, the results will be entered into a database with findings from around the world. (See Woodward results at www.worldwatermonitoringday.org.)

“In small groups, the kids really come through,” said Woodward science teacher Joyce Nishimura. “Just the fact that this is posted on the web or shared with the city, they take it very seriously.”

The student results will also be a part of the historical data being used by the city in setting up a comprehensive program of water quality and flow monitoring for the island. (See companion story.)

In past years, stream monitoring was done during science class, but because of heavy curriculum demands on class time, Nishimura said this year’s experiments are conducted by an after-school environmental club.

This day’s monitors, Kristin and Becky Gordon and Naomi Gaunavinaka, enjoyed the experience.

“I like sciences, so I thought it would be fun with friends,” Gaunavinaka said, while Kristin Gordon said it was her first time visiting an island stream.

“We always try to get kids to see the bigger picture,” said Laurie Spickard, a K-8 science lead teacher who helps Nishimura coordinate the water monitoring activities. “The value is, what does this data mean about our ecosystem? What does it mean about salmon who live here – including us?”

Low dissolved oxygen, a problem caused decaying matter in water, isn’t an issue in Manzanita, but has been in the news related to the Hood Canal, especially its southern end. In 2004, University of Woodward Middle Schoolers test water quality on the island, to get the big picture.

Washington measured average dissolved oxygen in the canal from below 3 mg per liter to just under 4 mg over the course of a year at depths below 20 meters (21.9 yards).

Excess nutrients in the water, such as from nitrogen-rich sewage, cause the algae population to explode or “bloom.” When it dies, dissolved oxygen is consumed as it decomposes.

In fresh water, too much phosphorus – once found in many detergents – caused a similar effect as nitrogen does in saltwater.

“It’s all a matter of balance,” Morse said. “If you have too much of any one thing, you have trouble.”

The acidity of the water is ideally around a pH of 7 – neutral. Manzanita was slightly “base” with a pH of 7.5. At a pH above 9, some fish can die. High turbidity, seen in high nephelometric units (NTUs), can damage the gills of fish and affects their ability to see and find food; Manzanita Creek showed a pristine 1.1 NTU.

At 25 NTUs, gills are damaged after five to 10 days and at 50 NTUs, salmon leave a stream entirely.

Cold water species favoring waters under 13°C (55°F) include sockeye, steelhead trout and chum. Cooler waters from 13°-20°C (55°-68°F) support cutthroat, coho and chinook, with warmer water fish like bass, shiners and bluegills happy in waters over 20°C (68°F). Manzanita was a cool 15°C (59°F).

Spickard says the club is planning to test the streams once a season. Woodward middle schoolers have been taking tests for over 10 years. When it was part of the curriculum, testing was as often as twice a week for many years.

“What I really believe is it becomes part of them so they remember it,” Nishimura said. “Later when they study it in high school or college, they will have that basic link to caring about the environment and doing something positive.”

* * * * *

The island in streams

Creek Oxygen pH Temperature Turbidity

Hidden Cove 7 mg/l 7.0 14°C (57.2°F) 4.2 NTU

Manzanita 10 mg/l 7.5 15°C (59°F) 1.1 NTU

Cooper 10.5 mg/l 7.5 11.9°C (53.4°F) Not available

Issei 9.74 mg/l 7.0 11.7°C (53°F) 2.9 NTU

Woodward 8.63 mg/l 7.8 12.8°C (55°F) 1.95 NTU

– at Eagle Scout overlook

Woodward 9.2 mg/l 7.9 12.9°C (55.2°F) 2.1 NTU

– at the end of the road

Data collected at 3:45 p.m. Oct. 17, 2005 on Bainbridge Island by Woodward Middle School students. See story for interpretive information.