A Washington Department of Fish and Wildlife press release on the Caspian
Terns/Salmon smolt interaction on the Columbia River.

Thought this would be of interest to all.

Grant Hendrickson
Redmond, Wa
granth at halcyon.com

> Sent: Friday, March 24, 2000 8:23 AM
> Subject: WDFW Fact Sheet Plans to address salmon predation by Caspian
> terns on Columbia
>
> March 2000
> Contact: Rocky Beach, WDFW Wildlife Program, (360) 902-2510
>
> Plans to address salmon predation
> by Caspian terns on Columbia River
>
> Since 1986, a growing colony of Caspian terns has been nesting on Rice
> Island 20 miles from the mouth of the Columbia River, consuming millions of
> salmon smolts as they migrate to the Pacific Ocean. This has prompted
> increasing concern by federal and state agencies, the tribes and others,
> since many of those young salmon are members of species listed as
> "threatened" or "endangered" under the Endangered Species Act (ESA).
>
> To address the issue of tern predation on listed salmon, the U.S. Army Corps
> of Engineers plans to scare ? or "haze" ? the birds off the island when they
> return to nest this year. Scientists from Oregon State University (OSU) also
> plan to use decoys and recorded calls to attract some of the terns to East
> Sand Island, approximately 15 miles down river near the mouth of the
> Columbia. A pilot project conducted in 1999 found that the terns consumed a
> much lower proportion of salmon at East Sand Island than at Rice Island.
>
> This year's effort to move the terns down river from Rice Island to East
> Sand Island is scheduled to begin April 1, 2000. The Washington Department
> of Fish and Wildlife (WDFW) supports the Corps' efforts to reduce tern
> predation on Columbia River salmon smolts and helped to develop this year's
> management plan as a member of a working group composed of neighboring
> states, tribes and federal agencies. WDFW will not, however, participate
> directly in the effort to displace the terns from Rice Island, which is in
> Oregon.
>
> Caspian tern populations
>
> Caspian terns are gull-like migratory birds that winter in southern
> California and Mexico before flying north to nest in the Pacific Northwest.
> The Caspian tern colony on Rice Island, a 230-acre deposit of dredged
> material east of Astoria, Oregon, is the largest of its kind in North
> America. Since 1986, the colony has increased by over 600 percent to a total
> of 8,100 breeding pairs in 1999. Prior to 1984, colonies were scattered from
> Grays Harbor and Willapa Bay to northern Puget Sound.
>
> Impact on salmon
>
> The terns on Rice Island nest and rear their young from April through July,
> which is also the peak migration period for juvenile salmon. Research has
> shown that the birds rely on salmon for 77 percent of their diet during that
> period, consuming approximately 12 million of the 100 million out-migrating
> smolts that reached the Columbia River estuary in 1997. At that rate, the
> Corps estimates that in 1999 the terns consumed 647,000 smolts listed under
> the ESA. The impact of this level of smolt predation on the returning
> population of endangered stocks is unknown, particularly as compared to more
> significant salmon mortality factors such as dams, harvest and habitat loss.
>
> The plan for 2000
>
> The Corps' long-term goal for the Rice Island terns is to disperse the birds
> into smaller colonies spread over a wide geographic area used by terns in
> the past to reduce predation on ESA-listed species. This approach also
> benefits the terns in that it will reduce the possibility that the species
> could be jeopardized by a catastrophic event such as an oil spill.
>
> For 2000, the immediate goal is to move the colony to East Sand Island,
> closer to the mouth of the Columbia. The advantage of moving the colony to
> East Sand Island is that the terns nesting there appear to have a more
> varied diet than those at Rice Island. Research conducted during the 1999
> pilot project found that salmon made up only 44 percent of the diet of terns
> relocated to East Sand Island, compared to 77 percent for those remaining at
> Rice Island. Other sites have been considered but require additional
> assessment.
>
> Terns prefer to nest in sandy areas, clear of debris. To help attract terns
> to East Sand Island, the Corps will maintain four acres for nesting on the
> island, which were initially cleared of vegetation and debris in 1999. A
> team from OSU will then use decoys and recorded calls to attract terns to
> the island, while other workers contracted by the Corps will chase birds off
> Rice Island ? as well as neighboring Miller Sands Spit and Pillar Rock
> Island ? throughout the nesting season.
>
> The Corps has filed an Environmental Assessment stating that its 2000 tern
> management plan will be consistent with the Migratory Bird Treaty Act,
> noting that the agency does not plan to use lethal measures to displace the
> birds and that the number of terns in the region is rapidly increasing.
> While WDFW supports the Corps' plan, the agency also recognizes its
> responsibility to protect Caspian terns and will be monitoring the situation
> closely in the Columbia River and in areas such as Willapa Bay, Grays Harbor
> and Puget Sound. WDFW will continue to insist that studies be conducted on
> the distribution, number and diet of birds in all areas and that
> contingencies be developed to ensure that the tern relocation efforts do not
> result in significant predation on salmonids outside the Columbia.
>