thumbnail

Pen rearing and imprinting of fall Chinook salmon. Annual report 1989

By:  and 

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS | Dublin Core

Abstract

The goal of this project is to compare net-pen rearing methods to traditional hatchery methods of rearing upriver bright fall chinook salmon (Oncorhvnchus tshawvtscha). Fish were reared at several densities in net pens at three Columbia River backwater sites during 1984-1987, and in a barrier net at one site during 1984-1986; methods included both fed and unfed treatments. The purpose of this report is to summarize the results obtained from the unfed treatments and the current return of adults from all fed treatments and the barrier net. Zooplankton were the primary food item of unfed fish. Fish reared in net pens utilized insects colonizing the nets as an additional food source, whereas those reared in the barrier net did not. Growth and production of fish reared in the unfed treatments were low. Instantaneous growth rates of unfed fish were much lower than those of the fed treatments and hatchery controls except when zooplankton densities were high and chironomid larvae were important in the diet of unfed fish reared in pens. Only fish in the barrier net treatment resulted in consistent net gains in growth and production over the rearing periods. Adult returns of fish from all fed and unfed treatments are lower than those of control fish reared at the hatchery. Returns appear to be inversely related to rearing density. Even though adult returns are lower than those of traditional hatchery methods, a cost-benefit analysis, as return data becomes more complete, may prove these methods to be an economical means of expanding current hatchery production, particularly if "thinning" releases were used.

Publication type Report
Publication Subtype Other Government Series
Title Pen rearing and imprinting of fall Chinook salmon. Annual report 1989
Year Published 1990
Language English
Publisher Bonneville Power Administration
Publisher location Portland, OR
Contributing office(s) Western Fisheries Research Center
Description iv., 33 p.
Google Analytic Metrics Metrics page
Additional publication details