Magnitude and Dynamics of Predation on Juvenile Salmonids in Columbia and Snake River Reservoirs, Annual Report of Research, 1989-1990.

Technical Report · Sun Jul 01 04:00:00 EDT 1990

DOI:https://doi.org/10.2172/6074775· OSTI ID:6074775

Petersen, J H

Three aspects of predation upon juvenile salmonids in the Columbia River are addressed in this report: (1) Indexing predator consumption. During 1989--1990, two indices of northern squawfish consumption upon juvenile salmonids were developed for use throughout the Columbia River Basin. The direct Consumption Index (CI) is based upon the concept of meal turnover time and takes into account number of salmonids, temperature, total gut content weight and predator weight. A Bioenergetics Index (BI) for consumption indexing was also developed to complement the direct CI. In the BI, growth, consumption, excretion/evacuation and respiration processes are modeled to predict the consumption required to produce an observed growth increment. (2) Studies on predator-smolt dynamics. Northern squawfish consumption data were collected in the McNary Dam tailrace during nine days in July 1988 to improve our understanding of the predator-smolt functional response. (3) Selective predation by northern squawfish. Laboratory and field protocols were developed to evaluate northern squawfish selection and prey vulnerability. Results from laboratory studies suggest that northern squawfish prefer dead over live prey and that descaled prey may be more vulnerable to predation than non-descaled prey. Stressed and unstressed prey were consumed in equal proportions when predation occurred for 6 or 24 h. Physiological and behavioral effects of stress on juvenile salmon are presented. 100 refs., 13 figs., 12 tabs.

• Research Organization: US Fish and Wildlife Service
• Sponsoring Organization: US Bonneville Power Administration
• DOE Contract Number: AI79-88BP91964
• OSTI ID: 6074775
• Report Number(s): DOE/BP-91964-1; ON: DE91006328
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540310 -- Environment
Aquatic-- Basic Studies-- (1990-)
550100* -- Behavioral Biology
59 BASIC BIOLOGICAL SCIENCES
ANADROMOUS FISHES
ANIMALS
AQUACULTURE
AQUATIC ECOSYSTEMS
AQUATIC ORGANISMS
BIOLOGICAL STRESS
COLUMBIA RIVER BASIN
DOCUMENT TYPES
DYNAMIC FUNCTION STUDIES
ECOSYSTEMS
EVALUATION
FISHES
FOOD CHAINS
Fishes - Mortality
JUVENILES
POPULATION DYNAMICS
PREDATOR-PREY INTERACTIONS
PROGRESS REPORT
SALMON
SNAKE RIVER PLAIN
VERTEBRATES