Lake Pend Oreille Fishery Recovery Project, 1998-1999 Annual Report.
The minimum water level of Lake Pend Oreille was raised from 625.1 m to 626.4 m elevation during the winter of 1998-99 in an attempt to recover the impacted kokanee Oncorhynchus nerka fishery. This report covers the third year of testing higher winter levels. Hydroacoustic surveys and mid-water trawling were conducted in the fall of 1999 to assess the kokanee population. We estimated the abundance of each age class of kokanee as: 6.023 million age-0 (wild and hatchery fry), 883,000 age-1, 409,000 age-2, 579,000 age-3, 861,000 age-4, and 87,000 age-5. Wild fry abundance was estimated at 2.57 million fish. These originated from 43.1 million eggs spawned in the wild during the fall of 1998. The survival from wild spawned eggs to wild fry was, therefore, 6.0%. This was lower than the 9.6% survival rate calculated last year but was much higher than the 1.4% calculated in 1995 prior to changing lake levels. To date, years of higher winter lake elevations have out-performed years of full drawdown. Based on data collected during trawl sampling, the total number of eggs laid in the lake in the fall of 1999 was 74.8 million. Mean fecundity per female was 379 eggs. Hatchery personnel collectedmore »
- Publication Date:
- OSTI Identifier:
- Report Number(s):
R&D Project: 199404700; TRN: US200213%%226
- DOE Contract Number:
- Resource Type:
- Technical Report
- Resource Relation:
- Other Information: PBD: 1 Dec 2001
- Research Org:
- Bonneville Power Administration, Portland, OR (US)
- Sponsoring Org:
- US Department of Energy (US)
- Country of Publication:
- United States
- 54 ENVIRONMENTAL SCIENCES; ABUNDANCE; DRAWDOWN; FEMALES; LAKES; MARSUPIALS; PERSONNEL; PROGRESS REPORT; SAMPLING; SHRIMP; TESTING; WATER KOKANEE SALMON -- EFFECT OF WATER LEVELS ON -- IDAHO -- PEND OREILLE, LAKE; FISHERY MANAGEMENT -- IDAHO -- PEND OREILLE, LAKE; SALMON FISHERIES -- IDAHO -- PEND OREILLE, LAKE.
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