Fishing in jeopardy as rivers get warmer and flows slow
Warm enough that some salmon are being transported across state lines, into Washington, to stay cool.
The U.S. Fish and Wildlife Service began trucking salmon from the Warm Springs National Fish Hatchery – located along the Warm Springs River in Central Oregon – to the Little White Salmon National Fish Hatchery, along the Columbia River outside Cook, Washington, in July, according to a Reuters report. Water temperatures of 76 degrees Fahrenheit were recorded in the Warm Springs River; historically, the river rarely tops 70 degrees.
“We will hold these little fish at Little White Salmon until around October, when the temperatures cool, then we will move them back to Warm Springs to let them finish maturing there,” U.S. Fish and Wildlife Service fisheries supervisor Rich Johnson told Reuters.
While Oregonians can escape yet another hot summer with air conditioning and travel, the state’s river, ocean and hatchery fish have no such luck. Warmer temperatures, like those recorded in the Warm Springs River, and low river and stream flows have put state and federal wildlife officials on alert.
“We’ve all gotten used to spring rains over the last decade or so bailing out mild winters,” said Bruce McIntosh, assistant director of the Fish Division of the Oregon Department of Fish and Wildlife. “It never happened this year.
“When the heat of July and August comes in May, you start going, I don’t know what this means anymore.”
Warm weather in May created catastrophes in June and July. Massive salmon die-offs were reported in the Willamette, Columbia, Deschutes and John Day rivers, among others, as river temperatures climbed into the 60s and upper 70s. (Salmon prefer water temperatures in the 50s.)
McIntosh and other state and federal officials are concerned that the fish lost in the rivers are not being sufficiently replaced through the natural cycle of spawning. Low river and stream flows have inhibited the ability of salmon to travel to traditional spawning grounds. According to a report by the U.S. Army Corps of Engineers, the Willamette River in Salem has experienced flows reduced from 5,800 cubic feet per second in mid-July to 5,500 cfs in mid-August; the Willamette’s flow has been reduced by as many as 450 cfs during the past month. The Santiam River in the mid-Willamette Valley has also seen its flow slowed by as much as 15 percent.
“The Umpqua (River) has seen serious temperature spikes,” McIntosh said. “These coastal systems have been at low summer flows since spring. One of our staff members came back from Medford (and) said the South Umpqua is turning down to puddles.
“Weather prognosticators said it’s going to be a long, dry, warm fall. Who knows? We might not see rain until Halloween. As this continues, and if it’s extended into fall, we’re going see salmon stacking up in the estuaries. They’ll become concentrated.”
And the die-offs could continue. To that end, ODFW has taken a “cautionary” tone with fish management, banning afternoon fishing in nearly all Oregon rivers in mid-July to help the fish survive the extreme conditions, an unprecedented decision for the state agency. “The response has been by and large positive,” McIntosh said.
Options for intervention are few; nature must take its course. The physical movement of hatchery salmon remains an option for state and federal agencies, as does placing further restrictions on fishing.
Even in persistently warm conditions, however, there appear to be plenty of fish left in Oregon’s waterways for fishermen to catch and for the next generation to supplant the previous one, according to McIntosh.
“The data tells us, we’re going to have a really great return of salmon and steelhead this fall,” McIntosh said. “That’s kind of the irony. Even this year, when you look at returns, we have had relatively strong returns across the state. We’re going into this in a pretty good condition. It’s how (the fish) get through the winter and the conditions when they go into the ocean.
“How long and how frequent these events could become, we don’t know. I wouldn’t say this is new norm, but when climates change like this you tend to see more extremes.”
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