PORTLAND DISTRICT

Below are summaries for management actions on or near East Sand Island.

Update as of Oct. 13, 2016

Individual adult Double-crested cormorants culled for the reporting period: 239
Total to date: 2,923

Individual adult Brandt's cormorants taken for the reporting period: 1
Total to date: 4

Individual adult Pelagic cormorants taken for the reporting period: 0
Total to date: 1

Nests oiled for the reporting period:  0
Total to date: 1,092

 

Update as of Oct. 6, 2016

The Corps resumed culling operations near East Sand Island on Oct. 3.

In order to meet the Corps’ year two management objectives and remain on track to meet NOAA Fisheries’ Biological Opinion guidelines by 2018, the Corps will cull up to 720 adult double-crested cormorants in October.

Individual adult Double-crested cormorants culled for the reporting period: 290
Total to date: 2,684 (corrected Oct. 13, 2016)

Individual adult Brandt's cormorants taken for the reporting period: 1
Total to date: 3

Individual adult Pelagic cormorant taken for the reporting period: 0
Total to date: 1

Nests oiled for the reporting period: 0
Total to date: 1,092

Information on the management plan and how the decisions were made can be found in Chapter 5 of the Double-crested cormorant Final EIS, which is posted in the Related Links section on this page.

 

Update as of Sept. 8, 2016

The Corps has regularly monitored the ESI cormorant colony following the initiation of breeding in July and August.  Currently, there are approximately 3,900 active double-crested cormorant nests on East Sand Island; nearly all nests contain between two and four chicks. The majority of double-crested cormorant chicks appear to be similarly aged in terms of their development, meaning the egg laying and hatching likely happened around the same time following return of adults to ESI in late June. Juveniles are showing continuous activity (walking around, flapping their wings, etc.), but none have been observed conducting short flights within or outside of the colony.  Based on the timing of egg laying and hatching, juveniles should begin to develop flight skills soon; the Corps will monitor and document the timing of these activities.

It should be noted that no management actions, including culling and egg oiling, have occurred since May, and no culling is planned at this time.  However, boat-based culling may occur after the chicks have fledged from their nests. The Corps may resume management activities later in the season (late September or early October) based on monitoring results over the next few weeks as chicks begin to fledge from their nests. 

Members of the public are reminded that visitors are not allowed on East Sand Island. The Corps’ guidelines regarding access to ESI are designed to minimize the impact to nesting birds.  The Corps is concerned that any visitation might trigger another dispersal event.

 

Update as of Aug. 3, 2016

Observers note some nesting behaviors

After approximately 23,000 Double-crested cormorants returned to East Sand Island in late June, on July 3 observers noted nesting behaviors from about 19,500 individuals.  Throughout July the number of nesting cormorants seen in aerial photographs decreased to a low of 8,500 on July 18, when the Corps’ monitoring crew and biologists conducted on-island monitoring.  They noted cormorants incubating nests with clutches of three to four eggs.

While the number of nesting birds has decreased since the cormorants returned to the island, in mid-July approximately 15,300 cormorants were seen loafing on the island, suggesting that while they are not nesting, many of the birds remain and are feeding in the lower estuary.  All management actions, including culling and egg oiling, have been suspended since May but may resume later in the season if the number of cormorants on East Sand Island meets the criteria outlined in Chapter 5 of the Double-crested Cormorant Final Environmental Impact Statement and Management Plan.

The Corps has been conducting weekly on-island surveys since July 18 and plans to continue monitoring the active nests on the island through surveys and aerial photography to document nesting and juvenile fledging activities.

Members of the public are reminded that visitors are not allowed on East Sand Island. The Corps’ guidelines for anyone accessing ESI are designed to minimize the impact to the nesting birds.  The Corps is concerned that any visitation might trigger another dispersal event.

Update as of June 29, 2016

Double-crested cormorants are returning to East Sand Island

More than six weeks after Double-crested cormorants abandoned their nesting sites on East Sand Island in the lower Columbia River, several thousand have returned to the nesting area in the past few days and Corps observers expect numbers to increase in the coming weeks.

On May 16, observers found that cormorants in the colony had abandoned about 8,600 nests.  As outlined in chapter 5 of the Double-crested cormorant Management Plan and Final Environmental Impact Statement, culling was immediately suspended. The Corps, U.S. Fish and Wildlife and U.S. Department of Agriculture – Animal Plant Health Inspection Service – Wildlife Services continue to research why the cormorants initially abandoned their nests, but the cause remains undetermined.

On June 22 Corps observers reported thousands of cormorants returning to the ESI nesting area.  Cormorant numbers on the island continue to increase, while the number of cormorants roosting on the Astoria-Megler Bridge is decreasing. Observers have often seen eagles flushing cormorants as small groups attempted to return the ESI. It appears that a group of cormorants large enough to resist being flushed by the eagles allowed them to re-establish the colony.

The number of cormorants actively nesting is not known at this time, but researchers are analyzing aerial photos of the island taken after the recolonization began and will have an estimated number of cormorants nesting population estimate by early July. All culling activity remains suspended but may resume later in the season if the number of cormorants on East Sand Island meets the criteria outlined in Chapter 5 of the Double-crested cormorant Final Environmental Impact Statement and Management Plan. 

Members of the public are reminded that visitors are not allowed on East Sand Island. The Corps’ guidelines for anyone accessing ESI are designed to minimize the impact to the nesting birds.  The Corps is concerned that any visitation might trigger another dispersal event. 

 

Update as of May 26, 2016

Culling activities are suspended. 

Independent monitors surveying the East Sand Island double-crested cormorant colony reported on Monday, May 16, 2016 that all nests had been abandoned. From field reports, including aerial photography, it appears that a significant disturbance to the colony occurred between May 13 and early May 16. This disturbance resulted in nest abandonment and the subsequent loss of cormorant eggs from predation by gulls, eagles and crows. 

We are following protocols outlined in the Final Environmental Impact Statement that guide management activities following a potential dispersal event. In accordance with these protocols, all culling and egg-oiling activities have ceased and cormorant monitoring in the lower Columbia River estuary continues. There has been no nest oiling since the evening of May 11 and we suspended boat-based culling May 16 upon learning of the on-island colony situation.

We don't know the cause of the disturbance and wildlife biologists from several federal agencies are gathering information toward determining its cause. Investigation of the colony area did not find any mammalian tracks. Federal biologists observed as many as 16 bald eagles on the colony on May 17. We are monitoring the colony to see if birds return. 

Double-crested cormorant breeding season typically peaks mid-June through July so there is time for birds to produce young this year, should they return. We will know more about the success of this year's colony at the end of this summer. 

The decision to resume culling and nest oiling this year hinges primarily on the number of double-crested cormorants that return to the colony and their behavior. 

While we have suspended culling activities, we continue our work on many environmental restoration projects on the Columbia River estuary continue to improve salmon recovery and support their lifecycle. To learn more about these efforts, please visit www.salmonecovery.gov.

For additional information on the Cormorant Management Plan, please reference the Final Environmental Impact Statement.

 

May 12-18, 2016

Individual adult Double-crested cormorants culled for the reporting period:   209

Total to date:  2394
Individual adult Brandt's cormorants taken for the reporting period:  0
Total to date:  2

Individual adult Pelagic cormorant taken for the reporting period: 1
Total to date: 1

Nests oiled for the reporting period:  1092
Total to date:   1092

 

May 5-11, 2016

Individual adult Double-crested cormorants culled for the reporting period:   691
Total to date:  2185

Individual adult Brandt's cormorants taken for the reporting period:  2
Total to date:  2

Nests oiled for the reporting period:  1092
Total to date:   1092

April 28 - May 4, 2016

Individual adult Double-crested cormorants culled for the reporting period:  469
Total to date: 1494

Individual adult Brandt's cormorants taken for the reporting period: 0
Total to date: 0

Nests oiled for the reporting period: 0
Total to date:  0

 

April 21-27, 2016

Individual adult Double-crested cormorants culled for the reporting period:  314
Total to date: 1025

Individual adult Brandt's cormorants taken for the reporting period: 0
Total to date: 0

Nests oiled for the reporting period: 0
Total to date: 0

 

April 14-20, 2016

Individual adult Double-crested cormorants culled for the reporting period: 440
Total to date: 711

Individual adult Brandt's cormorants taken for the reporting period: 0
Total to date: 0

Nests oiled for the reporting period: 0
Total to date: 0

 

April 6-13, 2016

Individual adult Double-crested cormorants culled for the reporting period:  271
Total to date: 271

Individual adult Brandt's cormorants taken for the reporting period: 0
Total to date: 0

Nests oiled for the reporting period: 0
Total to date: 0

In 2014, the U.S. Army Corps of Engineers released a draft Environmental Impact Statement and management plan to reduce predation of juvenile salmon and steelhead by double-crested cormorants in the Columbia River Estuary. In developing the plan, the Corps has worked closely with the following cooperating agencies: the U.S. Fish and Wildlife Service, the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service - Wildlife Services, the Oregon Department of Fish and Wildlife and the Washington Department of Fish and Wildlife.

East Sand Island's double-crested cormorant colony has grown from approximately 100 pairs in 1989 to 14,916 nesting pairs in 2013, which accounts for more than 40 percent of the western population. This breeding colony is the largest in North America.

The Corps has been conducting research studying the impact of avian predation on juvenile salmonids in the Columbia River Estuary since 1997. The research on East Sand Island contributes to understanding of the impacts cormorants have on juvenile salmonids migrating out to the ocean. Click here to see two graphics demonstrating the impact of the cormorant colony on East Sand Island to salmonids. The first graph shows annual consumption of juvenile salmonids by the colony. The second graph shows the seasonal proportion of salmon the double-crested cormorants consume during their nesting season.

In 2008, the Corps began small-scale management feasibility studies on the double-crested cormorant colony, restricting the birds from nesting in specific locations on East Sand Island. Study methods included hazing with lights, reducing nesting habitat and using human presence to flush double-crested cormorants off potential nesting sites.

In 2011, the studies focused on reducing the amount of available nesting habitat for double-crested cormorants on the western portion of the island and tracking the dispersal of radio- and satellite-tagged individual double-crested cormorants. Habitat reduction was primarily accomplished by installing barrier fences and using human hazers to flush birds from the non-designated nesting area.

In 2013, double-crested cormorants were restricted to 4.4 acres. Eighty-three adult double-crested cormorants were marked with satellite transmitters and several hundred adults were banded with leg bands to provide information about where double-crested cormorants would move during the dissuasion efforts. Although reduced by 70 percent, available habitat was not completely limited and 14,900 breeding pairs ultimately nested on the island. Near-term dispersal locations of radio and satellite tagged double-crested cormorants during the 2011–2013 breeding seasons were generally to four main areas identified in geographic proximity to East Sand Island:

1. Columbia River Estuary (defined as the tidally influenced 172 river miles from the mouth of the Columbia River to Bonneville Dam, including the Willamette River down to Willamette Falls Locks)
2. Outer Washington coast (Willapa Bay and Grays Harbor)
3. Puget Sound
4. Northern Salish Sea (San Juan Islands, Strait of Georgia, Vancouver, BC) (BRNW 2014).

Of these areas, the Columbia River Estuary has had the highest levels of use by double-crested cormorants during the dissuasion research in 2012 and 2013. There were no confirmed detections of radio- or satellite-tagged double-crested cormorants at inland sites east of The Dalles Dam, or at coastal sites south of Cannon Beach, Oregon.

In 2015, the Corps prepared a final Environmental Impact Statement and has made the document available for public review. Brig. Gen. John Kem, the U.S. Army Corps of Engineers Northwestern Division commander, signed a record of decision for the Double-Crested Cormorant Management Plan Final Environmental Impact Statement March 19, 2015. The ROD documents Kem’s decision and rationale for adopting the management plan to reduce predation on juvenile salmon and steelhead listed under the Endangered Species Act by a growing population of double-crested cormorants in the Columbia River estuary.

The Corps selected alternative C-1 in the final EIS, to carry out actions in the management plan. In phase one, actions would include culling individuals and oiling eggs to achieve a colony size of about 5,600 breeding pairs by 2018. In phase two, the western portion of East Sand Island would be inundated to preclude nesting, and the Corps would continue monitoring and hazing efforts. If needed, limited egg take would continue as well.

Alternative C-1 uses adaptive management methods to determine the following year’s actions. We will work with the U.S. Fish and Wildlife Service’s migratory bird team when developing each year’s actions. The team will analyze the long-term sustainability of the double-crested cormorant colony at East Sand Island and the western population. The number of individuals culled and eggs oiled in each year will be based on the team’s analysis.

To carry out the actions in the plan, The Corps of Engineers applied for and was granted a depredation permit from the U.S. Fish and Wildlife Service. The permit allows the Corps to cull a specific number of individual adults and oil a specific number of eggs to meet the plan’s goals. The Corps must apply for a depredation permit each year. 

Site preparation for management actions was completed on East Sand Island by mid-April. This included placing fencing to minimize disruption of other bird species also found on the island and help minimize disbursing the birds to other island and off-island nesting locations. The fencing also facilitates counting and tracking of the bird population.

The Corps released its final Environmental Impact Statement on Feb. 6, 2015. 

Brig. Gen. John Kem, the U.S. Army Corps of Engineers Northwestern Division commander, signed a record of decision for the Double-Crested Cormorant Management Plan Final Environmental Impact Statement March 19, 2015.

The Corps requested and received a depredation permit from the U.S. Fish and Wildlife Service on April 13, 2015. The permit allows the Corps to cull a specific number of individual adults and oil a specific number of eggs to meet the goals of the plan. The Corps must apply for a depredation permit each year. 

In 2008, NOAA Fisheries issued a Biological Opinion on the operations of the hydropower dams that make up the Federal Columbia River Power System. NOAA Fisheries concluded that operating the FCRPS in accordance with the BiOp would not jeopardize the continued existence of ESA-listed species; nor would it adversely modify or destroy the species’ critical habitat if the action agencies implemented the BiOp’s recommended reasonable and prudent alternative. The RPA includes improving fish passage at dams, managing flow, controlling predators that prey on young salmon, improving tributary and estuary habitat and reforming hatchery practices. Two RPA actions from the 2008 FCRPS BiOp specifically address management of double-crested cormorants in the Columbia River Estuary.

• RPA action 46 requires the development of a management plan for double-crested cormorants in the Columbia River Estuary and implementation of warranted actions in the estuary.
• RPA action 67 requires the double-crested cormorant population in the Columbia River Estuary and its impact on out-migrating juvenile salmonids to be monitored and implementation of a management plan to decrease predation rates, if warranted.

In 2014, NOAA Fisheries released the Supplemental FCRPS BiOp with a revised RPA action for reducing double-crested cormorant predation. RPA action 46 was revised to read: “The FCRPS Action Agencies will develop a cormorant management plan (including necessary monitoring and research) and implement warranted actions to reduce cormorant predation in the estuary to Base Period levels (no more than 5,380 to 5,939 nesting pairs on East Sand Island).”

The EIS alternatives address the management objectives recently identified in revised RPA action 46. This equates to reducing the current double-crested colony size by about 60 percent.

The range of alternatives under consideration to reduce double-crested cormorant predation of juvenile salmonids include implementing non-lethal and lethal actions to reduce the colony size on East Sand Island and limit their dispersal within the Columbia River estuary. Non-lethal methods include various hazing techniques to prevent colony establishment, modifying available habitat to limit colony size and conducting hazing activities off East Sand Island. Lethal methods include shooting individual double-crested cormorants and the take of eggs.

The Corps is the lead agency on the Environmental Impact Statement under the National Environmental Policy Act. The following agencies are cooperating: U.S. Fish and Wildlife Service; U.S. Department of Agricultures' Animal and Plant Health Inspection Service-Wildlife Services; the Oregon Department of Fish and Wildlife; and the Washington Department of Fish and Wildlife.