TESTIMONY OF DANIEL H. DIGGS, U.S. FISH AND WILDLIFE SERVICE, PACIFIC REGION, ASSISTANT REGIONAL DIRECTOR FOR FISHERIES, BEFORE THE SENATE APPROPRIATIONS SUBCOMMITTEE ON INTERIOR FIELD HEARING ON SALMON RESTORATION
APRIL 20, 2000
Mr. Chairman, I am honored to be here today and grateful to you for your efforts to bring focus to the issues surrounding salmonid restoration in the Northwest. I am Daniel Diggs, the Assistant Regional Director for Fisheries, and will provide testimony on behalf of the U.S. Fish and Wildlife Service (Service).
We appreciate this opportunity to contribute to the discussion on salmon recovery and hope that today's hearing can help people of differing perspectives work toward a common concern for salmon and their habitats. This issue has fostered an interagency effort within the Department of the Interior. As you may know, Dr. Daniel Roby, Assistant Unit Leader of the Oregon Cooperative Fish and Wildlife Unit of the United States Geological Survey, testified two days ago on this very subject before the Senate Energy and Natural Resources, Subcommittee on Water and Power. I will offer brief remarks on issues that I know are of specific concern to you and then will be happy to answer any questions you may have or provide any additional information you may need.
I understand you are interested in hearing more about seabird, particularly Caspian tern, predation and its impact on salmon restoration. The Service provides technical assistance on Migratory Bird Treaty Act issues and also serves in an advisory role on seabird predation through the Caspian Tern Working Group.
Caspian terns are a colonial nesting species native to the Columbia River and the Northwest. The terns first nested in the Columbia River estuary in significant numbers around 1984 when about 1,000 pairs were documented at East Sand Island. By 1996, this colony had moved to Rice Island, a Corps of Engineers dredge disposal island, and increased to roughly 8,000 pairs. Now Rice Island is one of only two known colonies along the coast of Oregon and Washington and supports about 10,000 pairs of Caspian terns.
As discussed by Dr. Daniel Roby of the United States Geological Survey, in 1998, research indicated that Caspian terns nesting on Rice Island consumed between 7 and 15 million smolts. This total consumption represents roughly six percent of the total number of smolts produced basin-wide, 80-90 percent of which are hatchery-produced. Losses of chinook salmon smolts are estimated to be less than one percent.
Declines in salmon populations occurred prior to the development of Columbia River estuary tern colonies. And despite avian predation, returns of hatchery reared chinook have been the highest on record over the last 10 years. However, in an effort to provide some short-term recovery benefit by reducing predation, the Caspian Tern Working Group developed a strategy to translocate the terns nesting on Rice Island to an island near the mouth of the estuary, known as East Sand Island.
Caspian terns feed on a wide variety of fishes -- specifically which fishes depends upon their availability. That is in part the rationale behind encouraging a shift in tern nesting from Rice Island back to East Sand Island where they nested in the mid 1980's. By moving the birds closer to the mouth of the estuary, there will be a greater mix of fish available to the terns, thus reducing the proportion of their diet that is made up of salmon smolts. In 1999, 1400 pairs of Caspian terns were successfully encouraged to relocate to East Sand Island. These birds had about 40 percent less salmonids in their diet compared to birds nesting on Rice Island. Our goal with the FY 2000 relocation effort is to see this 40 percent reduction realized for all outmigrating salmonid smolts, which should result in saving approximately 3 to 6 million smolts.
The Service recognizes that this effort to reduce predation may provide a short-term recovery benefit until more substantial efforts begin to restore salmon populations. However, the Service believes that Caspian tern predation on salmon smolts does not rise to the level of other causes of salmon mortality. The Service supports a step-by-step, science-based approach to managing fish-eating birds. A comprehensive assessment is needed to address all the factors that influence salmon recovery to enable managers to focus efforts on actions that will have the most significant benefit for salmon restoration. We must keep in mind, for example, that tern predation, much like salmon and trout decline, is at its base a habitat issue.
In that light, I want to also take advantage of this opportunity to thank you, Mr. Chairman, for the support you have provided to salmonid ecosystem restoration in the Northwest. We also thank you for your continued support for other Service efforts such as our nation-wide fish passage program (of direct benefit to the State of Washington already, with funding for work on Tahuya River on the west-side and Icicle Creek on the east-side), and other specific Service programs such as the 100th Meridian Initiative (and otherprojects), Chehalis River Restoration Project, Jobs-in-the-Woods, and Partners for Fish and Wildlife. All of these programs, and so much more, are needed for the restoration of salmon, bull trout, and other native species.
I also want to personally thank you, in my capacity as Assistant Regional Director for Fisheries, for your role in supporting the use of hatcheries for native fish restoration. The Service, as you are aware, has taken to heart the message from Congress to refocus our hatchery program to support the recovery and restoration of declining native salmonid stocks in the Northwest, while continuing to meet our federal mitigation and trust responsibilities.
Mr. Chairman, this concludes my prepared remarks. Again I thank you for the opportunity to participate in this discussion, which is so critical to the Northwest. I will be happy to answer any questions you may have.