Umatilla River Basin Avian Predation III

Effects of avian predation on salmon and steelhead were identified as critical uncertainties in the Columbia River Anadromous Fish Restoration Plan of the Nez Perce, Umatilla, Warms Springs, and Yakama Tribes. We propose to estimate the number, distribution, and movements of pelicans on local rivers seasonally to determine the annual impacts on salmon and steelhead. This proposal is an extension and expansion of existing work funded with FY 2022 and 2023 PCSRF funds (projects 22-Umat-08 and 23-Umat-06).



Proposed work involves five main components:

1) Estimate PIT tag deposition rates on colony islands.

2) Estimate pelicans annual predation of steelhead and salmon smolts.

3) Document pelicans abundance and distribution on the Umatilla River, Columbia, Walla Walla, and Lower Snake Rivers.

4) Assist CRITFCs falconry hazing efforts on the Hanford Reach during fall Chinook smolt releases. Utilize falcon hazing at smolt acclimation facilities on the Umatilla River during smolt releases.

5) Radio tag pelicans and monitor their seasonal and daily movements including their response to falconry hazing efforts and resulting movements.



Worksite #1 Umatilla River:

We will estimate the annual impact of pelican predation on ESA-listed Mid-Columbia River steelhead smolts and reintroduced spring Chinook salmon smolts in the Umatilla River. We will use PIT tag deposition rates onto bird islands, smolt PIT tag totals, and smolt PIT tags detected on the islands to estimate the consumption of steelhead and salmon smolts by pelicans in the Umatilla River. We will conduct weekly bird counts from the air (recording numbers and GPS locations) to estimate the number of pelicans using the Umatilla River (79 river miles) for feeding and resting during the primary smolt out-migration season (March through June. Pelican counts will document their temporal and spatial distributions in the Umatilla Basin. We will radio tag pelicans at Three Mile Dam, Westland Dam, and the Pendleton area and will monitor radio tagged pelicans seasonal and daily movements before, during, and after hazing efforts on the Umatilla and Columbia River. We will subcontract with Sky Guardian Falconry to haze pelicans away from smolt acclimation facilities at Pendleton and areas upstream during smolt releases in April and May of 2025.



Worksite #2 Columbia River:

We will conduct aerial pelican counts (with GPS locations) every other week during the spring (April - June) to document their abundance and distribution. We will assist the falconry abatement efforts funded by CRITFC in early June with jet boat transportation and related logistical support. Radio tagging of pelicans will be conducted on or near the pelican breeding colony at Badger Island, islands on the Hanford Reach, and/or similar locations once a collection permit is obtained. We will monitor the behavior of radio tagged pelicans for seasonal and daily movements.



Worksite #3 Walla Walla River:

We will monitor the abundance and distribution of pelicans on the Walla Walla River every other week by fixed winged aircraft during the primary smolt out-migration season (April-June. We will monitor the behavior of radio tagged pelicans before, during, and after hazing efforts on the Umatilla and Columbia River. We will estimate the annual impact of pelican predation on the survival of ESA-listed Mid-Columbia River steelhead smolts and reintroduced spring Chinook salmon smolts in the Walla Walla River



Worksite #4 Lower Snake River:

We will conduct aerial bird counts (with GPS locations) to document the abundance and distribution of pelicans using the Lower Snake River during the primary smolt out-migration season (April through June). Will monitor the behavior of radio tagged pelicans before, during, and after hazing efforts on the Umatilla and Columbia River.



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We will provide fisheries managers with empirical data regarding the impact of pelicans on smolts in the Umatilla, Walla Walla, and Lower Snake basins. Determine if American white pelicans contribute significantly to the high mortality of ESA-listed Mid-Columbia summer steelhead smolts and reintroduced spring Chinook salmon.. Pelican hazing efforts during smolt releases are designed to reduce predation of smolts by pelicans during the first few days after smolts are released into the Umatilla River. Will also evaluate the use of falconry to push pelicans off key feeding areas in the Hanford Reach and reduce predation of fall Chinook smolts by pelicans. Fall Chinook provide substantial harvest opportunities in the Zone 6 fishery and are an important component of the fall season commercial harvest. Pelican radio tagging efforts will document when and where pelicans move throughout the Columbia River Basin seasonally and daily and how they respond to falconry and other hazing actions.