Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in the John Day Pool. 1982 Annual Report.

Technical Report · Thu Mar 01 04:00:00 EST 1984

DOI:https://doi.org/10.2172/5485797· OSTI ID:5485797

Gray, Gerard A

This study was initiated to determine the extent of predation by resident populations of native and introduced fish on juvenile salmonids in main stem Columbia River Reservoirs. The John Day Reservoir and tailrace was selected as the study area. First year objectives were: (1) determine whether native and introduced predators preyed on juvenile salmonids; (2) determine which species were major predators; and (3) locate areas where predation was most intense. Results indicated that juvenile salmonids were consumed by all four predatory fish species studied: northern squawfish (Ptychocheilus oregonensis), walleye (Stizostedion vitreum vitreum), smallmouth bass (Micropterus dolomieu), and channel catfish (Ictalurus punctatus). However, degree of predation varied among predators as a function of spatial distribution, apparent abundance, size, and temporal feeding behavior. 15 figs., 16 tabs.

• Research Organization: Fish and Wildlife Service, Cook, WA (USA)
• DOE Contract Number: AI79-82BP34796
• OSTI ID: 5485797
• Report Number(s): DOE/BP-695; ON: DE85016651
• Country of Publication: United States
• Language: English

Related Subjects

520500* -- Environment
Aquatic-- Site Resource & Use Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
AGE DEPENDENCE
ANIMALS
AQUATIC ORGANISMS
COLUMBIA RIVER
CONSUMPTION RATES
DAILY VARIATIONS
DATA
EXPERIMENTAL DATA
FEDERAL REGION X
FISHES
FOOD
Fishes - Food - Columbia River
INFORMATION
NORTH AMERICA
NUMERICAL DATA
PREDATOR-PREY INTERACTIONS
Predation (Biology)
RIVERS
STREAMS
SURFACE WATERS
USA
VARIATIONS
VERTEBRATES
WASHINGTON