Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in John Day Reservoir, 1986 : Annual Report.
This report summarizes activities in 1986 to determine the significance of predation on juvenile salmonids in John Day Reservoir. Salmonids were the single most important food item (by weight) for northern squawfish (Ptychocheilus oregonensis) at McNary tailrace during all sampling periods and at John Day forebay during July. Salmonids accounted for 23.7% of the diet of walleye (Stizostedion vitreum vitreum) in July 1986, which was higher than in previous years (although the sample size examined was low). Salmonids contributed little to smallmouth bass (Micropterus dolomieui) diet but comprised about 25% of the diet of channel catfish (Ictalurus punctatus). Composition of prey taxa in beach seine catches in July 1986 was similar to previous years with chinook salmon (Oncorhynchus tschawytscha), largescale sucker (Catostomus macrocheilus), and sand roller (Percopsis transmontana) dominating the catch.
- Research Organization:
- Fish and Wildlife Service, Cook, WA (USA). Willard Field Station
- DOE Contract Number:
- AI79-82BP34796
- OSTI ID:
- 6440011
- Report Number(s):
- DOE/BP-34796-3; ON: DE87009910
- Country of Publication:
- United States
- Language:
- English
Similar Records
Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in John Day Reservoir, 1984 : Annual Report.
Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in the John Day Pool : 1983, Annual Report.
Related Subjects
130600 -- Hydro Energy-- Environmental Aspects
520500* -- Environment
Aquatic-- Site Resource & Use Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ANADROMOUS FISHES
ANIMALS
AQUATIC ORGANISMS
COLUMBIA RIVER
FISHES
Fishes - Food - Columbia River
PREDATOR-PREY INTERACTIONS
Predation (Biology)
RIVERS
SALMON
STREAMS
SURFACE WATERS
VERTEBRATES
WATER RESERVOIRS