More Letters, Meetings About What To Do With Salmon-Eating Cormorants On Astoria Bridge; Chase Them Back To East Sand Island? Culling?
In a January letter, the Northwest Power and Conservation Council invited Oregon and Washington transportation agencies to meet jointly to discuss their mutual problem of double-crested cormorants on the Astoria-Megler Bridge that spans the Columbia River estuary at Astoria, OR.
A U.S. Army Corps of Engineers’ effort to cull and move the cormorants away from East Sand Island lower in the estuary to protect salmon and steelhead smolts the birds were preying on had been successful, but most of the birds instead just moved upstream to the bridge to nest, turning the move into a “whack-a-mole” problem, according to some Council members at their meeting this week in Victor, MT.
New information presented to the Council at its November meeting showed that the birds which had taken up residence on the bridge continued to prey on juvenile salmonids and in an area of the river where their breeding and foraging have far higher per capita predation rates on juvenile salmon and steelhead smolts compared to when they were breeding and foraging from East Sand Island, according to a June 6 Council memorandum .
“Because the abundance of marine forage fishes progressively declines upstream, double-crested cormorants breeding on the bridge and locations upstream consume more salmonids. Estimates of estuary-wide predation rates from 2015 – 2020 are much higher since the Corps’ actions to reduce their numbers on East Sand Island,” the memo says.
For the Oregon Department of Transportation and the Washington State Department of Transportation, which jointly own the bridge, the nesting cormorants could be “accelerating corrosion of the Astoria-Megler Bridge, causing significant structural damage,” the January letter from the Council to the transportation agencies said. “In addition, there are human safety issues regarding bird strikes on the roadway that need to be alleviated.”
The Council’s January 11, 2023 letter is here.
Acknowledging that the shift of the cormorant colony from East Sand Island to the bridge is reducing the life expectancy of the paint protecting the steel trusses of the bridge, inhibiting safety inspections and creating safety conflicts with motorists, the March 31 response from Oregon and Washington was to invite a Council representative to sit on an advisory committee overseeing a study the two agencies will be conducting this summer.
“In response to the cormorant issues, ODOT and WSDOT will be conducting a Value Engineering Study this summer to develop solutions intended to reduce the number of cormorants using the Astoria-Megler Bridge,” the response letter says. “The Value-Engineering Study will consist of a facilitated multidisciplinary team meeting over four days to develop a range of potential actions to reduce cormorant use of Astoria-Megler Bridge.”
Once the study is completed, the two agencies said they would sit with the Council to discuss the problem, but that meeting likely would not occur until later this fall.
The agencies’ response letter to the Council is here.
While ODOT, WSDOT and the Council all want to move the double-crested cormorants off the bridge, the Council’s concerns are where will the birds go.
“If there is an effort to remove the birds from the bridge, where will they go?” queried Patty O’Toole, director of the Council’s Fish and Wildlife Division. “Can we encourage them to move further down into the estuary where they will find different food?”
“It’s important for tribes, states and federal agencies to all be at this meeting,” said Jeff Allen, Council member from Idaho, and Council chair. “This is not just whack-a-mole for birds, it is for these agencies, too.”
“Yes, we do chase this issue around the basin,” O’Toole said. “Some of these agencies are chafing about the changing goal posts,” referring to the work to reduce the double-crested cormorant population at East Sand Island that was completed in 2018 by the Corps.
Mike Milburn, Council member from Montana, suggested “thinning the herd” as they do with cattle in Montana.
“This is a problem associated with abundance,” agreed Ed Schriever, Council member from Idaho. “There is an opportunity, Mr. Milburn, to ‘thin the herd.’ The Council needs to advocate for population management to address this long-term conflict.”
As the former director of the Idaho Department of Fish and Game, Schriever said he is aware of exceptions to the Migratory Bird Act that already allow for culling cormorants. Nationally, 121,000 of the birds are allowed to be “taken” and 4,500 are allowed in the Pacific flyway. Last year, only 900 of that Pacific flyway take permit was used, he said.
The Council instructed O’Toole to draft a letter to be sent to ODOT and WSDOT to encourage the agencies to include tribes, and state and federal agencies when meeting.
For background, see:
— CBB, January 26, 2023, COUNCIL REACHES OUT TO STATE AGENCIES TO DISCUSS ‘ALARMING CONCLUSIONS’ OF STUDY DETAILING IMPACTS TO SALMON FROM CORMORANTS ON ASTORIA BRIDGE, HTTPS://CBBULLETIN.COM/COUNCIL-REACHES-OUT-TO-STATE-AGENCIES-TO-DISCUSS-ALARMING-CONCLUSIONS-OF-STUDY-DETAILING-IMPACTS-TO-SALMON-FROM-CORMORANTS-ON-ASTORIA-BRIDGE/
— CBB, November 16, 2022, WHERE TO PUT THE BIRDS? RESEARCH SAYS CORMORANTS CHASED OFF COLUMBIA RIVER ESTUARY ISLAND EAT FAR MORE SALMON, STEELHEAD UPSTREAM, HTTPS://CBBULLETIN.COM/WHERE-TO-PUT-THE-BIRDS-RESEARCH-SAYS-CORMORANTS-CHASED-OFF-COLUMBIA-RIVER-ESTUARY-ISLAND-EAT-FAR-MORE-SALMON-STEELHEAD-UPSTREAM/
— CBB, March 10, 2022, WHACK-A-MOLE: AGENCY THAT CHASED SALMON-EATING CORMORANTS OFF ESTUARY ISLAND NOW HAZING RE-LOCATED BIRDS ON ASTORIA BRIDGE OVER COLUMBIA RIVER, HTTPS://CBBULLETIN.COM/WHACK-A-MOLE-AGENCY-THAT-CHASED-SALMON-EATING-CORMORANTS-OFF-ESTUARY-ISLAND-NOW-HAZING-RE-LOCATED-BIRDS-ON-ASTORIA-BRIDGE-OVER-COLUMBIA-RIVER/
— CBB, July 20, 2018, “Fewer Cormorants Nest At East Sand Island, Observers Document Bald Eagle Predation On Eggs,” https://columbiabasinbulletin.org/fewer-cormorants-nest-at-east-sand-island-observers-document-bald-eagle-predation-on-eggs/
— CBB, May 4, 2018, “Cormorants Return To East Sand Island But No Lethal Removal This Year; Hazing, Egg Take,” https://columbiabasinbulletin.org/440651.aspx
–CBB, March 16, 2018, “Corps Decides Not to Cull Estuary Cormorants In 2018, Will Continue Hazing, Egg Removal,” https://columbiabasinbulletin.org/440367.aspx/
–CBB, September 22, 2017, “Estuary Cormorants Nesting In Low Numbers; Corps Unsure If Culling Will Resume Before Season Ends,” https://columbiabasinbulletin.org/439600.aspx
–CBB, August 11, 2017, “Due To Low Numbers Of Estuary Cormorants Showing Nesting Activity, Culling Remains Suspended,” https://columbiabasinbulletin.org/439412.aspx
–CBB, July 7, 2017, “Corps Continues Suspension Of Culling Salmon-Eating Cormorants In Estuary,” https://columbiabasinbulletin.org/439223.aspx
–CBB, June 16, 2017, “With Cormorant Nesting On East Sand Island Stalled, Boat-Based Shooting Of Birds Suspended,” https://columbiabasinbulletin.org/439105.aspx
–CBB, April 28, 2017, “Third Year Of Shooting Salmon-Eating Cormorants, Oiling Nests: Goal Is To Kill 2,409 Birds,” https://columbiabasinbulletin.org/438803.aspx
— CBB, September 9, 2016, “Court Allows Continued Culling Of Cormorants In Columbia Estuary To Reduce Predation On Salmonids,” https://columbiabasinbulletin.org/437461.aspx
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