Comment on proposed FY 2006 budget

We desire renewal of the project in FY 2006. This project is 1997-024-00 "Avian Predation on Juvenile Salmonids in the Lower Columbia River," which is in the Mainstem/Systemwide province. FY05 funding approved and granted for this project was $250,000. The FY 2006 budget of $470,000 is consistent with our expectations and sufficient to implement the scope and activities approved for the project. The increase in funding from FY 2005 to FY 2006 is commensurate with the expansion of the research program to become more focused on the system-wide impacts of avian predation on juvenile salmonids. More focus will be placed on measuring the impacts of the expanding double-crested cormorant colony on East Sand Island as well as the Caspian tern colony on Crescent Island. We will also provide a basin-wide assessment of the current distribution, colony size, and population trajectories of fish-eating waterbirds (i.e., terns, cormorants, gulls, and pelicans) along the lower Columbia River from the estuary to the head of McNary Pool. Predation impacts of those colonies posing the greatest risk to salmon survival will be thoroughly investigated, as will the management options to reduce those impacts. Some cost sharing from the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service is expected for related work but outside the scope of this proposal.

Accomplishments since the last review

In addition to the extensive work we have done to monitor and evaluate management actions implemented to reduce the impacts of Caspian terns on juvenile salmonids in the Columbia River estuary, we have recently increased our efforts to evaluate the impacts of other avian predator populations on the lower Columbia River. This comprehensive effort includes nesting colonies of cormorants, gulls, pelicans, and terns on the Columbia River from the mouth to the head on McNary Pool. These recent efforts have revealed that although numbers of Caspian terns nesting in the Columbia River estuary have remained stable over the last 7 years, the numbers of double-crested cormorants nesting on East Sand Island have more than doubled during the same period to ca. 12,500 pairs. This colony is now the largest known breeding colony for the species in North America. Although juvenile salmonids represented only ca. 5% of the diet of cormorants nesting on East Sand Island in 2004, estimated smolt consumption by the cormorant colony is now comparable to that of the East Sand Island tern colony. The double-crested cormorant colony on East Sand Island has experienced high nesting success in recent years, and the colony is expected to continue to expand for the foreseeable future. Despite the much smaller numbers of salmonid smolts consumed annually by the Crescent Island tern colony, predation rates on particular salmonid stocks have been surprisingly high, particularly in low flow years. Crescent Island terns consumed a minimum of 21% of the in-river migrating Snake River steelhead smolts in 2004. The relatively high predation rate on in-river migrants from the Snake River was, however, offset greatly by transportation, a benefit not afforded to steelhead from the Upper Columbia River ESU. The extent of system-wide smolt losses to avian predators is being investigated as part of this research program, as are methods to reduce smolt losses to birds (e.g., relocation of nesting cormorants using habitat manipulation and social attraction).

FY 2006 goals and anticipated accomplishments

The Final EIS for Caspian tern management in the Columbia River estuary lists the redistribution of the majority of the East Sand Island colony to alternative colony sites outside the Columbia Basin as the preferred alternative. A goal of our research will be to monitor and evaluate the effects of the implementation of the preferred alternative. We will assess how management affects the distribution of terns on the Columbia River from the estuary to the head on McNary Pool and will notify management agencies if terns displaced from East Sand Island attempt to nest elsewhere along the Columbia River. We will quantify the system-wide impacts of terns on smolt survival to evaluate whether tern management in the estuary reduces tern predation. Results from our study will be provided to resource managers in-season so that terns can be adaptively managed. Management options to reduce smolt losses to the expanding double-crested cormorant colony on East Sand Island have yet to be considered and will require additional research and NEPA analysis. Another goal of our research will be to collect the information necessary to critically evaluate the benefits to juvenile salmonids of managing cormorants in the estuary. We will generate precise and reliable estimates of smolt consumption, determine the cause(s) for the expansion of the estuary population, assess the boundaries of the management unit that includes the East Sand Island colony, and amass the demographic data to predict the population trajectory and future risks from cormorant predation on smolt survival. Finally, we will evaluate the efficacy of various options for managing cormorants to reduce their impacts. Lastly, our research will provide a basin-wide assessment of the distribution, colony size, and population trajectories of fish-eating waterbirds along the lower Columbia River. Predation impacts of those colonies posing the greatest risk to salmon survival will be thoroughly investigated, as will the management options to reduce those impacts.

Subbasin planning

How is this project consistent with subbasin plans?

Work not related to subbasin plan; part of Mainstem/Systemwide.

How do goals match subbasin plan priorities?

Work not related to subbasin plan; part of Mainstem/Systemwide.

Other comments