Study: killing cormorants tripled losses of salmon & steelhead

(Beth Clifton collage)

“This goes down as one of the really significant failures in wildlife management in recent decades.”

PORTLAND, Oregon––Cormorant massacres at East Sand Island,  near the mouth of the Columbia River between Oregon and Washington,  not only did not save any salmon and steelhead from predation in 2015 through 2017,  but may have tripled predation losses,  according to new research by Oregon Department of Fish & Wildlife avian predation biologist James Lawonn.

“The U.S. Army Corps of Engineers killed 5,576 cormorants and destroyed 6,181 nests in an effort to prevent the birds from eating an estimated 12 million young salmon each year,”  summarized Karina Brown for Courthouse News Service and Willamette Week on February 5,  2019.

Double-crested cormorant.
(Sally Fekety photo)

“Little to no gain”

Lawonn,  however,  told Brown that he expects “expects little to no gain” in salmon and steelhead survival as result of the killing,   ordered by the U.S. Army Corps of Engineers and executed by USDA Wildlife Services

Explained Brown,  “That’s because cormorants are now living farther upriver—still in huge numbers.  And where they live makes a difference.  Cormorants who live closer to the ocean choose from an extensive menu of ocean fish that form huge schools in the Columbia estuary,  such as anchovies,  herring and smelt.  Upriver, they eat a far higher proportion of salmon and other freshwater fish.

“None of the estimated 16,000 birds who fled East Sand Island in 2017,  amid the USDA Wildlife Service gunfire,  “were tagged or radio-collared,  so there is no data to show exactly where they went.  But last year,  a sudden surge in cormorants nested on the Astoria-Megler Bridge,  seven miles upriver from the island,  and at other upriver spots.”

Bridge cormorant colony “will likely double”

Some cormorants had nested at the Astoria-Megler Bridge,  spanning the Columbia River,  since 2004,  “but only in very small numbers,”  Brown specified,  paraphrasing Lawonn.

“Now there are 1,750 breeding pairs on the bridge,”  Brown wrote,  “and based on available habitat,  the colony will likely double.”

Altogether,  the Columbia River estuary cormorant population has recovered to about 10,000 nesting pairs,  “a number comparable to the original average of 12,000 pairs on East Sand Island before the Corps of Engineers project,”  Brown assessed.  “Other spots upstream have become new homes for 750 breeding pairs.”

Bob Sallinger.  (Facebook photo)

Feds knew killing cormorants would not help

That the cormorant massacres would do little or nothing to conserve salmon and steelhead was no surprise to Audubon Society of Portland conservation director Bob Sallinger.

The outcome should also have been no surprise to the U.S. Army Corps of Engineers and other agencies involved in the killing,  Sallinger contended in an unsuccessful 2015 lawsuit,  based on a suppressed and ignored study by U.S. Fish & Wildlife Service biologist Steve Haeseker.

(See Feds hid data showing that killing cormorants will not help salmon & steelhead.)

Cormorant catching a fish.
(Beth Clifton photo)

“One of the worst things I’ve seen”

“We think this goes down as one of the really significant failures in wildlife management in recent decades,”  Sallinger told Brown.  “It’s without question one of the worst things I’ve seen in my 25 years of wildlife advocacy.”

“This was never about protecting salmon,” emphasized Sallinger.  “This was always about scapegoating birds to avoid the real challenges that the Corps of Engineers needs to face up to. And the result has been a stunning failure,  whether you care about birds or fish.”

Sallinger and many other conservationists have long blamed salmon and steelhead declines in the Columbia River estuary on the many upstream dams blocking the Columbia,  the Willamette,  and other spawning rivers.

(Beth Clifton photo)

Dams & hot water

“The U.S. Army Corps of Engineers has refused to do what’s necessary to modify those dams to protect salmon,”  Sallinger has often said,  “and that is why salmon are continuing to decline. Killing wildlife is not going to change that situation.”

Several reports indicate that global warming is also a major and growing factor.  Effects of elevated water temperature have been found by at least one recent study to be contributing to the premature deaths as many as half of the adult sockeye salmon returning to the Columbia River and tributaries to spawn.

(Beth Clifton photo)

Feds blame eagles

The U.S. Army Corps of Engineers,  meanwhile,  denied to Brown that shooting thousands of cormorants and smashing their nests had anything to do with their 2017 exodus from East Sand Island.

Instead,  wrote Brown,  “The Corps blames eagles for the birds’ mass abandonment of the island.”

“The management plan has been very successful in reducing the amount of salmon eaten by birds on East Sand Island,”  contended U.S. Army Corps of Engineers biologist Kris Lightner.  “We just don’t know about the estuary as a whole.”

(Beth Clifton collage)

“Pure scapegoating”

Responded Oregon State University wildlife ecology professor Dan Roby,  who was hired by the Corps of Engineers to study the potential effects of rousting cormorants from East Sand Island,  but whose advice was ignored,  “If there is a place in the Columbia River estuary where it would be best for cormorants to nest – and by best,  I mean their effect on salmon and steelhead survival – it would be East Sand Island.”

Brown published her exposés of the failure of the cormorant killing to help salmon and steelhead on the same day that ANIMALS 24-7 published Why killing predators won’t bring back the salmon,  examining and exposing schemes pursued by a variety of state and federal agencies to try to recover salmon and steelhead by killing gulls and California sea lions.

Beth & Merritt Clifton

All of this,  said Sallinger,  “is a continuation of a very unfortunate pattern of killing wildlife to protect other wildlife––pure scapegoating.”

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