Before moving forward with a dam, flood leaders want to know: how are aquatic species using the Upper Chehalis River Basin? The Washington State Department of Fish and Wildlife is conducting five fish and habitat studies to answer that question.
One is a riverscape study, a broad survey of the Chehalis in which data was collected through observation via walking and snorkeling.
Beginning July 15, biologists traversed the 48 miles from the east and west fork confluence, to the proposed dam site, past Elk Creek, past the South Fork of the Chehalis and past the Newaukum.
“We found a lot of diverse habitat for many diverse species,” Fish and Wildlife Research Scientist Mara Zimmerman said at a flood workshop at the Great Wolf Lodge last Wednesday. “We’re focusing our research and technical work on 27 native fish species, including salmon and steelhead, minnows, including the Olympic mudminnow, suckers, lamprey, mountain whitefish, sturgeon and stickleback.”
The Chehalis also supports exotic fish, including bass and catfish, and amphibians.
“It was very much a first look to see where are the fish and what is their habitat, how many fish are using the main stem during summer flows above and below the dam site,” Zimmerman said.
To gather preliminary information on fish movement, the biologists tagged 1,614 Coho and 232 Steelhead and tracked them using sensors on the main stem and three of the Chehalis’ tributaries.
The biologists finished collecting data Oct. 25 and will analyze the information over the winter, Zimmerman said.
