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Discussion Starter · #1 ·
Was out shad fishing around Clackamette last night a saw A LOT of dead springers floating downriver. At least 20 in the three hours I was there, plus another 10 or so on the bank. I've never seen this many before.

Is this normal mortality? Warm water / oxygen level?

Shad fishing was slow but steady. Red and white Dick Nite worked best, fished on a 3' dropped on the bottom
 

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It's thermal, most likely...ODFW is out sampling today and is fearing the worst for late arrivals...Willamette has heated up.

:palm:
 

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It can be common on hot, low water years. The Willamette is running @ 75 degrees now.

Good thing there are already 50,000 past the falls.
 

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Reporter is working on it, I think.
Some coming out of the Clackamas, too, but only lower. It's still below 70 farther upriver.
 

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Discussion Starter · #6 ·
Water temp was as high as 77 degrees last night. Low was around 71 degrees up closer to the falls.

Just seemed strange there were so many dead ones at once.
 

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Flows and temps like this have never been measured within the period of record. It would be a lot worse too without the stored water being released by the Corps dams. :twocents:

Some tributaries will likely see virtually no fish survive to spawn. Going to be in the 90's next week too...

Hope I am wrong!
 

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Is it possible that these salmon could be weakened and more susceptible due to being compromised by the toxic algae blooms?
 

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ODFWs recent press release;

June 18, 2015
CLACKAMAS, Ore. – Elevated water temperatures are most likely the cause of spring Chinook salmon deaths in the Willamette River and some of its tributaries, according to fish biologists from the Oregon Department of Fish and Wildlife.
Spring Chinook salmon typically die in the fall after they have spawned. However, some also die before they are able to spawn as the result of stress, disease, and predation. This year, Chinook are dying earlier than usual, according to Tom Friesen, manager of ODFW’s Upper Willamette Research, Monitoring and Evaluation Program.
ODFW biologists and survey crews have observed unusually large numbers of spring Chinook salmon carcasses in the Willamette, Clackamas, and Santiam rivers recently.
“Pre-spawning mortality is normal and happens every year to some extent,” said Friesen. “But usually we don’t see dead spring Chinook in the mainstem Willamette until mid-summer.”
ODFW biologists say that high water temperatures likely contributed to the death of the fish.
Chinook salmon are more prone to disease, injury, and stress when water temperatures exceed 60° F. At 70°, the fish start to get into real trouble.
For the past week, water temperatures in the Willamette River have risen steadily, from 70° to 74° F. During the same period, Clackamas River water temperatures rose from 62° to 64° while the Santiam rose from 62° to 66°.
“We get concerned about the impact on Chinook anytime water temperatures approach 70 degrees,” said Friesen.
If forecast drought conditions and elevated water temperatures persist, some spring Chinook will likely continue to die before they have a chance to spawn, especially in the mainstem Willamette and lower portions of tributaries.
The good news is that the Willamette basin is experiencing one of the strongest spring Chinook salmon returns in years. Through, June 13, more than 51,000 Chinook had passed upstream through ODFW’s fish counting station at Willamette Falls, exceeding the 50-year average of 41,000 Chinook.
“Fortunately, many of this year’s spring Chinook have already entered the tributaries, which should help ensure their survival,” Friesen said.
Despite higher than normal water temperatures, most of the region’s hatcheries are doing well and are on track to meet their brood stock needs, according to Manny Farinas, ODFW’s North Hatchery Group coordinator.
“Throughout the region our hatcheries have been experiencing higher water temperatures earlier in the season,” added John Thorpe, ODFW’s Willamette South Hatchery Group coordinator. “We had planned for this and have successfully adjusted fish husbandry practices to respond.”
 

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Friday, Tuesday and Wednesday of this week I fished between McIver and Barton and saw a steady number of dead fish floating by. This is the beginning of what will likely be a huge fish kill.

Sent from my HTCONE using Tapatalk
 
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