MARCOLA, Ore. - A healthy stream burbles past downed logs beneath overhanging trees, a combination that helps cool the temperature of the stream water -- and makes for great fish habitat.
A new study from the Oregon Department of Environmental Quality says there are not enough of these streams in the Willamette Basin.
If fish could complain, they would say it's too darn hot: The new DEQ study says about 70 percent of rivers and creeks in the basin are too warm for salmon, trout and other cold-water fish.
"In general, trout and salmon really get uncomfortable at 68 degrees, to the point where they're looking for something else," said District Fish Biologist Jeff Ziller of the Oregon Department of Fish and Wildlife.
Mill Creek, which runs into the Mohawk River, it's a stream on the mend after heavy logging from 25 years ago.
Ziller points to returning forest canopy, which is not yet very tall. "Right now, you can see those conifers right there are not allowing the shade to hit the stream," Ziller said.
Temperatures will drop as the trees get taller, Ziller said. At nearby Shotgun Creek, another tributary of the Mohawk, the fish would have no complaints.
"A nice canopy like this lets a little bit of sunlight in," Ziller said. Researchers in the study found strong connections linking damaged streamside vegetation, higher temperatures and impaired stream life.
"The river system and tributary system and the health of those river systems is really critical," DEQ Water Quality Program Manager Michael Wolf said. "Over time, the Willamette system has been impaired because of human development."
While the new report is kinder to streams on forest lands, biologists said it's going to take time to reverse years of damage to the Willamette Basin. The study sampled 650 sites throughout the Willamette Valley, combining work done by scientists, watershed councils and Oregon State University researchers.