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1994 Columbia River Basin Fish and Wildlife Program |
| Council document 94-55 | |
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< Section 10 table of contents
10.6 Other Resident Fish Populations
10.6A Rainbow Trout in the Clearwater River
Idaho Department of Fish and Game
10.6A.1 Provide information to the Council on whether habitat in the Clearwater River below its North Fork is suitable for rainbow trout. If the habitat is suitable and production of rainbow trout will not conflict with production of chinook salmon, provide a plan to stock the river with rainbow trout. Coordinate development of this plan with the Nez Perce Tribe and the National Marine Fisheries Service.
Bonneville
10.6A.2 Upon completion of the actions specified in Section 10.6A.1, and upon Council review and approval, fund the program for stocking rainbow trout in the Clearwater River.
10.6B Salmonids and Spiny-Rayed Fish in Pend Oreille River
Corps of Engineers
10.6B.1 Fund a study to evaluate the existing and potential salmonid and spiny-rayed fish and their habitat in the Pend Oreille River from Lake Pend Oreille downstream to Albeni Falls Dam. Coordinate this study with the Idaho Department of Fish and Game, Washington Department of Fish and Wildlife and Kalispel Tribe of Indians. Submit recommendations based on results of these studies. Upon approval by the Council, fund recommendations.
10.6C Sturgeon and Burbot in Kootenai River
Bonneville
10.6C.1 Fund efforts to restore sturgeon and burbot populations in the Kootenai River. These populations are dependent on the productivity of fish habitats in the entire Kootenai River system including the Kootenay River and Kootenay Lake in British Columbia. Coordinate and share the cost of this measure with Canadian fishery managers.
10.6D Kokanee in Banks Lake
Bureau of Reclamation or Appropriate Irrigation Districts
10.6D.1 Fund maintenance of the barrier net system at the outlet from Banks Lake into the main irrigation canal to conserve the spawning population of kokanee in the lake.
10.6E Kokanee in Lake Pend Oreille
The Council endorses adaptive management techniques and targeted research to improve environmental conditions and provide data concerning critical uncertainties. The same approach should be applied to uncertainties regarding Lake Pend Oreille.
The decline in kokanee populations from the 1960s to the mid 1990s has been debated in terms of magnitude of decline and factors causing the decline. Shoreline spawning counts have declined from 39,400 in 1953 to 1,900 in 1992. The Idaho Department of Fish and Game believes that there would be an increase in spawning habitat if lake levels were held up. Other factors such as predation, mysis shrimp introduction and other food web changes have also been suggested as possible causes of decline and limits on population size.
An experimental regime in which winter water levels are maintained above 2,051 feet would test whether spawning habitat limits kokanee populations, and whether recruitment would be significantly enhanced by higher water levels. Managing winter water levels to 2,054 feet in 1995-96, 2,055 feet in 1996-97 and 2,056 feet in 1997-98 would provide sufficient new spawning habitat to permit such a test.
Because the kokanee population is low and variable, and weak year classes are forecast, there is an urgent need to understand the causes of decline. Research should provide data to address uncertainties regarding: movements of shoreline gravel; any impacts or benefits to Box Canyon Reservoir; a lake energy budget including zooplankton; predation levels and predator abundance; mysis shrimp and kokanee; changes in the abundance of warmwater fish species; concerns about Eurasian water milfoil; and effects on wildlife and waterfowl. Many elements of this research are needed prior to making long-term decisions regarding lake level management.
Therefore, the Council calls for maintaining Lake Pend Oreille levels at an elevation of 2,054 feet in 1995-96, 2,055 feet in 1996-97 and 2,056 feet in 1997-98 from early November until April for three winters.
Idaho Department of Fish and Game and Appropriate Tribes and State Agencies
10.6E.1 Prepare a study plan for Council review by September 1995 to investigate the effect of changing water level management of Lake Pend Oreille starting in the fall of 1995. Address as a part of the study: the effect of lake level changes on kokanee production; possible movements of shoreline gravel and sediment; any impacts or benefits to Box Canyon Reservoir; a lake energy budget, including zooplankton; predation levels and predator abundance; mysis shrimp and food availability for larval and adult kokanee; changes in the abundance of warm water fish species; concerns about Eurasian water milfoil; and effects on wildlife and waterfowl. During the term of the study implement hatchery improvements identified in previous studies on Cabinet Gorge Hatchery, maintain current levels of kokanee production and maintain current levels of harvest.
Independent Scientific Group
10.6E.2 Review the study design and implementation, including appropriate lake levels, at the earliest opportunity and submit a review to the Council by September 1, 1996. The Council will then confirm or modify the final study design.
Bonneville
10.6E.3 Fund the Lake Pend Oreille kokanee study as approved by the Council.
Corps of Engineers
10.6E.4 Change lake level minimums to 2,054 feet, 2,055 feet and 2,056 feet during the next three winters. These lake levels should be implemented only if monitoring and evaluation measures (spawning related studies) are in place. Drafts below these levels are permissible in case of power emergencies to protect system reliability (see Section 1.8 on system reliability and emergencies). Any replacement energy for these operations must not come from Columbia River Basin storage projects. Funding for research associated with these operations is subject to the ongoing process for project ranking and prioritization.