Testing the waters just a day's work

Posted: Thursday, July 01, 2010

On a sunny June day as fly fishermen peered down into the Anchor River searching for salmon, Sue Mauger, a stream ecologist with Cook Inletkeeper, also waded the swift waters. Mauger was on the hunt for something equally precious -- at least to a scientist.

Data. Good, solid scientific data.

A month ago, Mauger had set out a sealed piece of black plastic pipe tied to a weight on the bottom of the stream. Finding the pipe, Mauger brought it to shore. She unscrewed a cap and pulled out a small scientific instrument about the size of a two-dollar stack of quarters.

Every 15 minutes year-round since 2002, that little data logger has been measuring stream temperatures, and every month Mauger or another Inletkeeper worker swaps out loggers. Back at the lab, the loggers are connected to computers and their information added to a developing information set that shows not just seasonal temperature changes, but stream temperature changes from year to year.

The Anchor River is one of 48 salmon streams in the Cook Inlet watershed being monitored under the direction of Inletkeeper as part of its Salmon Stream Monitoring Project. Cook Inletkeeper celebrates its 15th anniversary this year. Although many know Inletkeeper for its environmental advocacy, Mauger's work shows another side of the Homer-based nonprofit organization: good solid research.

Since 1996, Inletkeeper began testing lower Kenai Peninsula creeks as part of its Citizens Environmental Monitoring Project, or CEMP. That program has expanded to 250 sites in the Cook Inlet watershed, an area about the size of Maine that goes north to the furthest reaches of the Susitna River and its tributaries.

While CEMP volunteers record information like dissolved oxygen, turbidity and bacteria, it misses another part of the picture. Are streams getting warmer? That's the question the Salmon Stream Monitoring Project looks at.

"There hasn't been a comprehensive effort to look at stream temperature," Mauger said. "That's why we embarked on this."

On the Anchor River survey, Mauger's assistant, Marcella Dent, helped her log the day's measurements. Dent is a University of Alaska Anchorage senior working on a bachelor of science in environment and society. This summer she's on loan to Inletkeeper under an internship program sponsored by the Alaska Conservation Foundation.

Since 2008, Inletkeeper has worked with other Cook Inlet organizations to do similar stream temperature monitoring. Although the Anchor River is monitored year round, most other sites are measured from June to September. The furthest north site is on the east fork of the Chulitna River north of Talkeetna.

As some scientists look at global climate change, others look at regional effects. That's the important question in Alaska.

"People ask 'Are you seeing any effects of climate change?' I would argue 'Yes,'" Mauger said. "We're warmer now than in the past for water temperature."

One defect with the Salmon Stream Monitoring Project is its relatively short collection period.

"We're always collecting our baseline data too late," Mauger said.

However, Alaska has good air temperature information going back to the 1930s. Scientists can compare air and water temperature.

"Once I know that here in present time, I can use that relationship to see what water temperatures used to be," Mauger said. "I can backcast."

To better define that relationship, the Salmon Stream Monitoring Project also measures air temperature. Data logger thermometers also are hung in trees near the stream sites, with the loggers also swapped out monthly.

The big concern with water temperature is the effect of warming water on fish, especially salmon. Critical temperatures are 55.4, 59 and 68 degrees Fahrenheit. In the past 30 years, Cook Inlet streams have usually been cooler than 55.4 degrees. Recently, some streams have been 60 to 62 degrees in the warmer summer months of July and early August. At warmer temperatures, salmon eggs and fry start getting stressed.

"The stress in the watershed is enough it could have an impact on the productivity of the river system," Mauger said.

Information on stream water temperatures will be used by policy planners. Land managers like boroughs and cities might use the information to protect streams -- expanding vegetation set backs to provide cooling shade, for example, or focusing revegetation efforts in certain areas.

Monitoring rivers, keeping streams cool and protecting fish habitat all fits in with Inletkeeper's mission of protecting Cook Inlet's watershed and the life it sustains.

"We feel it's important we understand the health of our watersheds. It has a lot of impact on the health of our community," Mauger said. "In Alaska, climate change is a local problem."

All the information collected is public data, Mauger said, and is periodically made available in reports for review by other scientists and citizens. For information on Inletkeeper programs, visit its Web site at www.inletkeeper.org.

Michael Armstrong can be reached at michael.armstrong.@homernews.com.

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