Management implications of a model of predation by a resident fish on juvenile salmonids migrating through a Columbia River reservoir

North American Journal of Fisheries Management
By: , and 

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Abstract

We constructed a model ofpredation by northern squawfish Ptychocheilus oregonensis on juvenile salmonids migrating through John Day Reservoir. The model predicts salmonid survival as a function of number and distribution of northern squawfish, number and timing of juvenile salmonids entering the reservoir, salmonid residence time, water temperature, and flow. The model predicted survival similar to independent estimates for 1983–1986 and also approximated differences among areas and months. Uncertainty analyses showed that the number of salmonids surviving predation may vary ±5% with normal annual variation in predator number, temperature, and flow. Survival in 1983–1986 was near the average predicted from 30 years of historic environmental data. Sensitivity analyses implied that the best avenues ofreducing predation are to reduce the number of northern squawfish, pass salmonids earlier in the year, and maintain sizes of runs of juvenile salmonids at or above present levels. Survival of salmonids, as simulated by the model, is weakly affected by changes in predator distribution, changes in predator consumption rate near the upstream dam, residence time, or flow.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Management implications of a model of predation by a resident fish on juvenile salmonids migrating through a Columbia River reservoir
Series title North American Journal of Fisheries Management
DOI 10.1577/1548-8675(1990)010<0290:MIOAMO>2.3.CO;2
Volume 10
Issue 3
Year Published 1990
Language English
Publisher Taylor & Francis
Contributing office(s) Western Fisheries Research Center
Description 15 p.
First page 290
Last page 304
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