Where are the Fish?

Hillsboro, OR — September 30, 2005 — Clean Water Services and the Tualatin River Watershed Council are conducting a survey of fish, macroinvertebrate water insects, aquatic habitat and water quality in 16 streams in the Tualatin River Watershed to monitor the health of the watershed. This project started ten years ago, and biologists will return to the same 64 sites that were surveyed before, looking for aquatic life and habitat elements such as riffles and pools, woody debris, and shade.

“The research provides critical information on the number, distribution, and condition of fish in urban and rural streams which is used in developing policies and programs to help improve water quality and habitat,” said water resources program manager Jan Miller. “It’s important to understand where the fish are and the quality of their habitat to help measure our progress toward watershed health.”

Biologists will use electrofishing units to stun the fish briefly so they can be measured and examined. They will also be counting crayfish and macroinvertebrates which are indicators of stream health. While in the streams, the scientists will measure aquatic habitat units by documenting the number and size of pools and riffles, large woody debris, shade cover, beaver activity and beneficial habitat. They will also look for problems including eroding and undercut streambanks, invasive non-native plants, and barriers to fish passage. Finally, the scientists will sample water quality for temperature, dissolved oxygen, pH, turbidity, velocity and other parameters that affect fish viability.

This survey work is part of a comprehensive watershed health monitoring strategy that includes 24- hour monitoring of flows in the Tualatin River and tributary streams, weekly water quality monitoring at 35 sites, and continuous monitoring of water chemistry at eight sites in the river and tributaries.

“The District has been protecting and improving water quality in the Tualatin Basin for 35 years,” Miller said. “These surveys help to ensure that our investments in healthy streams pay dividends for native fish, water quality and our ratepayers.”

The Tualatin River Watershed Council is a watershed stewardship organization that promotes and encourages sustainability and watershed-wise practices in the Tualatin River watershed. The Council was formed in 1993 and is comprised of 20 stakeholder representatives

Clean Water Services is a water resource management utility for more than 480,000 people in urban Washington County and small portions of Multnomah County, Clackamas County, Lake Oswego, and Portland. Clean Water Services operates four wastewater treatment facilities, constructs and maintains flood management and water quality projects, and manages flow in the Tualatin River to improve water quality and protect fish habitat. Although Clean Water Services maintains a close working relationship with Washington County government, it is a separately managed and financed public utility.

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