Lake Pend Oreille Fishery Recovery Project, 1996-1997 Annual Report [electronic resource].

Published:: Washington, D.C. : United States. Dept. of Energy, 1999.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Physical Description:: 33 pages : digital, PDF file
Additional Creators:: United States. Bonneville Power Administration, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information

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Summary:

During the winter of 1996-97, the elevation of Lake Pend Oreille was kept 1.2 m higher in an attempt to recover the impacted Kokanee fishery. This was the first winter of the scheduled three-year test. We found that kokanee spawned on the newly inundated gravels provided by the higher water levels. Many of the redds were at depths of 0.5 to 2 m with the highest density of redds at the 1.2 m depth. We also found the numbers of kokanee spawning in tributary streams declined sharply with the higher lake levels. Presumably, these fish spawned on the lakeshore because of the abundance of shoreline gravel rather than migrate up tributary streams. Kokanee spawning sites were mapped around the entire perimeter of the lake. Most spawning occurred at the southern end of the lake; however, kokanee utilized the newly available spawning gravels throughout much of lake's shorelines. Unusually high spring run-off in 1997 produced an inflow to the lake of 4,360 m³/s and raised the lake 1 m above full pool. We found that all age-classes of kokanee declined sharply between 1996 and 1997. Survival rates of all age-classes were at or near the lowest point on record. The cause of these declines is unknown; possible causes include kokanee emigrating from the lake and mortality of kokanee due to dissolved gases in the northern third of the lake reaching 120% to 130% of saturation. High dissolved gases were caused by the Cabinet Gorge and Noxon dams on the Clark Fork River. Kokanee population declines caused by flooding would have masked any benefits to the population resulting from a higher winter lake level.

Report Numbers:

E 1.99:doe/bp-98065-2
doe/bp-98065-2

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Note:

Published through SciTech Connect.
09/01/1999.
"doe/bp-98065-2"
"Contract 1994BI12917"
Elam, Steve; Maiolie, Melo A.; Harryman, Bill.

Type of Report and Period Covered Note:

Annual; 10/01/1996 - 09/30/1997

Funding Information:

1997BI98065

View MARC record | catkey: 14138739