NOAA and Oregon sign an overdue agreement
You don’t have to be an expert on Northwest salmon to know they have been on a collision course with rising temperatures. There have been news items in recent years — including this summer — about returning salmon sweltering and dying in the Klamath Basin and the Willamette River.
It stands to reason that adult fish returning from years in cold ocean waters will struggle when the water — and hence their own body temperature — is drastically higher than what they are used to. Like most organisms, salmon are adaptable to a point and there is much variation between different species and runs. But every creature has its limits, and the 21st century’s climate has started testing the outer boundaries of adaptability for many Columbia Basin salmon.
There was news last Tuesday of an agreement by NOAA Fisheries to work with Oregon officials over the next three years to begin dealing with rising water temperatures by locating, protecting and restoring cold-water habitat in the Columbia and Willamette.
This is overdue.
As early as 2001, the U.S. Environmental Protection Agency issued a major report about the impacts of rising water temps on salmon and other fish species. (www.tinyurl.com/FishTempStudy) It found a complex situation, but came to an overall conclusion that many species are harmed by higher temps.
For example, “salmonid stocks that make long-distance migrations to inland spawning grounds during the summer and fall may be more vulnerable to increased water temperatures and loss of cold-water refuges.”
What constitutes cold water differs from species to species, but species of vital interest in the Columbia River require colder water than they often now encounter. For instance, fall/summer Chinook prefer a spawning temperature of 41 to 56 degrees; spring Chinook 40 to 64; coho and steelhead 50 to 55; sockeye 36 to 46.
In its latest work, NOAA Fisheries identifies 68 degrees as the level at which some major species become weak and diseased or died. They may have trouble spawning or thriving well before that point.
It is vital to find and protect places along the salmon migration route where they can be refreshed by colder water. This will likely impact some accustomed fishing places and will further complicate fishing seasons. The Columbia’s treaty tribes certainly must share in this effort.
Salmon and the fishermen who rely on them need careful nurturing as this warm century progresses.