[env-trinity] MedfordMailTrib: Heat may overcook Rogue River chinook

[Sari Sommarstrom]

 http://www.mailtribune.com/article/20150731/ENTERTAINMENTLIFE/150739980

OUTDOOR JOURNAL

Heat may overcook chinook

By Mark Freeman
Mail Tribune 

Posted Jul. 31, 2015 at 12:01 AM 

GOLD BEACH - Seeing the seining crew nab 15 wild fall chinook salmon from
the Rogue River Wednesday at Huntley Park east of town should be a good sign
for inland anglers with chinook on their minds.

These big fish in the survey net are the first real shot of prized chinook
this season to head out of the Rogue bay toward the middle Rogue, where
hordes of anglers await them in the most popular Grants Pass-area fishery of
the year.

But with triple-digit air temperatures gripping the Rogue Valley, this best
of times could become the worst of times.

Migrating chinook are headed into a cauldron of hot and likely lethal lower
Rogue waters prime for a drought-triggered disease outbreak that's so far
sidestepped the Rogue during one of the hottest and driest years on record.

But as hot as it will get this weekend, the image of belly-up chinook is
almost inevitable.

"It'll be lava," says Pete Samarin, a fish biologist on the Rogue for the
Oregon Department of Fish and Wildlife. "That river's going to be slow and
it's going to be hot.

"It's going to be hard for anything to survive, chinook-wise," he says.

Rogue River temperatures at Agness are expected to eclipse 80 degrees, hot
enough to trigger a columnaris outbreak, which biologists feared would take
out significant chunks of the Rogue spring chinook run, and which is now
drawing a bulls-eye on the upcoming fall chinook run.

The ones that have migrated past Huntley Park by now could be goners this
week, but that's just the early tip of what has become a robust wild chinook
run. The only hope is today's 108-degree air will cook the Rogue so hot that
chinook won't venture upstream out of the bay's relatively cool,
salt-infused waters.

"We'll see," Samarin says. "But it's not good."

It is good, however, if you happen to fish west of the head of tidewater.

Bay trollers are running into chinook that aren't finning upstream in any
large numbers like they normally would at this time of year.

"It's not red-hot, but it's been good," says Jim Carey, who keeps tabs on
the bay's fishing pulse from his Rogue Outdoor Store in Gold Beach.

Red-hot has not been a positive phrase in the history of Rogue fall chinook,
whose numbers historically have been tamped down by regular columnaris
outbreaks in the Agness area and the Lower Rogue Canyon due to low, hot
summer flows.

But summer flow augmentation from Lost Creek Lake has changed that, cooling
the Rogue most years to stave off this natural disease outbreak and creating
very popular late-summer fisheries first in the bay, then the canyon and,
finally, the Grants Pass-Gold Hill environs.

Drought years, however, can take their toll, like in 1992 when low water
triggered a columnaris outbreak that killed off almost 70 percent of the
spring chinook run and triggered an emergency fishing closure.

Shades of '92 were feared this year, but some deft water-release juggling
and a very timely rainstorm helped get virtually all the springers to the
upper Rogue disease-free.

The Bureau of Land Management reports no dead salmon in the canyon all of
last week, so protecting that run has been a success.

But the current wave puts the all-wild fall run in peril, particularly any
that get the itch to move out of the bay this weekend.

"Those chinook in the bay," Samarin says, "just need to stop."

But they won't stop forever.

Within two weeks, the chinook will start showing up in the Huntley Park
survey nets. When they do, ODFW's water-management strategy calls for
increasing Lost Creek Lake releases from 1,500 cubic feet per second to
1,900 cfs in an attempt to cool the water in the Agness area to palatable
levels.

A dearth of natural tributary flow, however, means 1,900 cfs might be the
flow at Agness. In the past, that's not been good enough to stave off
disease if it's met with another round of triple-digit temps.

"I don't know if that'll be good enough," Samarin says. "My intuition tells
me otherwise."

Reach reporter Mark Freeman at 541-776-4470 or mfreeman at mailtribune.com.
Follow him at www.twitter.com/MTwriterFreeman.

 

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