In Northwest streams, high temperatures and low flow levels are creating harsh conditions for fish. That’s the finding of a new study.
Two stream conditions can stress fish: high temperatures and low flow. In past decades, temperatures reached their highest levels during the summer in Northwest streams. Water flows would be most shallow about three months later, in the fall.
Researchers looked at how this typical pattern has held up during a 60-year period. The scientists discovered that in recent years, only one month separates the high point for water temperatures and the low point for stream flows.
That means fish have less time to recover.
Ivan Arismendi is a researcher at Oregon State University. He says climate change is causing this new pattern. The Pacific Northwest has seen less snowpack, and it’s melted earlier in the year.
Arismendi says not all Pacific Northwest streams are affected. He says groundwater-fed streams did not change as much.
Copyright 2012 Northwest Public Radio