Kokanee Stock Status and Contribution of Cabinet Gorge Hatchery, Lake Pend Oreille, Idaho, 1990 Annual Progress Report.

Technical Report · Fri Mar 01 00:00:00 EST 1991

DOI:https://doi.org/10.2172/5908843· OSTI ID:5908843

Paragamian, Vaughn L

Rehabilitation of kokanee Oncorhynchus nerka in Lake Pend Oreille met with some success in 1990, but unexpected results have raised new questions. Estimated kokanee abundance during late August of 1990 was about 6.9 million fish. This is a decline of 19% from 1989, a continued decrease since 1988. The decreased population was attributed to low stocking of hatchery fry (7.3 million), lower wild fry survival in 1990 (1.5%), and exceptionally poor survival of fish ages 3+ and 4+. Average survival of the older fish was only 11% in 1990 compared to 72% in prior years. Compensatory survival was noted for kokanee ages 1+ and 2+, with an average of 81% in 1990 compared to 44% in 1989. Hatchery fry comprised 47% of the total kokanee fry recruitment in 1990 (80% of fry biomass). This contribution ranked third behind 1988 and 1989 since hatchery supplementation began in the 1970s. Survival of hatchery fry was 20%, the second highest since this investigation began. Findings of 1990 indicate a more comprehensive approach to managing kokanee must take into account predator stockings and predator/prey interaction. An unexpected low adult escapement was responsible for an egg-take of only 5.6 million eggs in 1990, 58% of the previous year, which will limit experimental stocking in 1991. Modification of the fish ladder at the Cabinet Gorge Fish Hatchery to improve adult escapement is strongly recommended to increase egg-take. 27 refs., 28 figs., 6 tabs.

• Research Organization: Idaho Dept. of Fish and Game (IDFG)
• Sponsoring Organization: United States. Bonneville Power Administration.
• DOE Contract Number: 1985BP22493
• OSTI ID: 5908843
• Report Number(s): DOE/BP-22493-6; R&D Project: 1985-339-00; ON: DE92005346
• Country of Publication: United States
• Language: English

Related Subjects

13 HYDRO ENERGY
54 ENVIRONMENTAL SCIENCES
59 BASIC BIOLOGICAL SCIENCES
COMPILED DATA
MONTHLY VARIATIONS
DAMS
ENVIRONMENTAL EFFECTS
ENVIRONMENTAL IMPACTS
FISHES
HATCHING
PREDATOR-PREY INTERACTIONS
SURVIVAL CURVES
POWER GENERATION
FISHERIES
HYDROELECTRIC POWER
IDAHO
MIGRATION
MONITORING
MORTALITY
POPULATION DYNAMICS
PROGRESS REPORT
REARING
SALMON
WATER QUALITY
ZOOPLANKTON
ANADROMOUS FISHES
ANIMALS
AQUATIC ORGANISMS
DATA
DEVELOPED COUNTRIES
DOCUMENT TYPES
ELECTRIC POWER
ENERGY SOURCES
ENVIRONMENTAL QUALITY
FEDERAL REGION X
INFORMATION
NORTH AMERICA
NUMERICAL DATA
PLANKTON
POWER
RENEWABLE ENERGY SOURCES
USA
VARIATIONS
VERTEBRATES
Kokanee salmon - Geographical distribution
130600* - Hydro Energy- Environmental Aspects
540350 - Environment
Aquatic- Site Resource & Use Studies- (1990-)
550100 - Behavioral Biology