Abundance and Distribution of Walleye, Northern Squawfish and Smallmouth Bass in John Day Reservoir and Tailrace, 1983 Annual Report.
- Oregon Department of Fish and Wildlife, Columbia River Section, John Day, OR
Walleye, northern squawfish and smallmouth bass abundances were estimated in portions of John Day Reservoir and tailrace using a multiple mark and recapture method. Sampling was conducted from March 28 to September 23, 1983, using gill nets, trap nets, boat electrofishing, angling and an angler survey. A total of 1808 walleye, 6423 northern squawfish and 974 small mouth bass were collected. Abundance was estimated using a modified Schnabel estimator. Discrete populations were defined according to observed movements of recaptured and radiotagged fish. Abundance estimates were corrected for angler harvest, size selectivity by gear and recruitment due to growth during sampling. In addition, the likelihood of biases resulting from differential mortality of marked fish and tag loss was examined. Abundances of walleye with fork lengths greater than 250 mm were estimated as 6877 below John Day Dam and 9,463 in the upper John Day pool. Extensive movements by walleye within pools were observed. Angler harvest of walleye between May 25 and September 6 was estimated as 527 in John Day tailrace and 465 in McNary tailrace. Abundances of northern squawfish with fork lengths greater than 250 mm were estimated to be 32,126 below John Day Dam, 10,841 forebay and 27,771 in upper John Day pool. The estimated number of northern squawfish in the McNary tailrace boat restricted zone after cessation of spill (July 2) was twice the estimated abundance during spill (March 28-July 1). Smallmouth bass abundance was estimated as 1087 below John Day Dam, 1501 in John Day forebay and 3,450 in upper John Day pool. 16 refs., 32 figs., 47 tabs.
- Research Organization:
- Oregon Dept. of Fish and Wildlife, Corvallis (USA)
- Sponsoring Organization:
- United States. Bonneville Power Administration.
- DOE Contract Number:
- 1982BP35097
- OSTI ID:
- 5447558
- Report Number(s):
- DOE/BP-35097-1; R&D Project: 198201200; ON: DE85016233
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
- Country of Publication:
- United States
- Language:
- English
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Abundance and Distribution of Walleye, Northern Squawfish and Smallmouth Bass in John Day Reservoir and Tailrace, 1984 Annual Report.
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Related Subjects
ANADROMOUS FISHES
ABUNDANCE
SAMPLING
BASELINE ECOLOGY
COLUMBIA RIVER
OREGON
SIZE
SPATIAL DISTRIBUTION
WASHINGTON
WATER RESERVOIRS
ANIMALS
AQUATIC ORGANISMS
DISTRIBUTION
ECOLOGY
FEDERAL REGION X
FISHES
NORTH AMERICA
RIVERS
STREAMS
SURFACE WATERS
USA
VERTEBRATES
Fish populations - John Day Reservior (Or. and Wash.)
520100* - Environment
Aquatic- Basic Studies- (-1989)