Record Details

Effects of logging on the growth of juvenile coho salmon

ScholarsArchive at Oregon State University

Field Value
Title Effects of logging on the growth of juvenile coho salmon
Names Iwanaga, Paul M. (creator)
Hall, James D. (advisor)
Date Issued 1971-05-10 (iso8601)
Note Graduation date: 1971
Abstract The objective of this research was to study the effects of increased water temperature characteristic of clearcut watersheds of Pacific coastal streams upon the growth rate of juvenile coho salmon. The natural temperature fluctuations of the stream were used in the study of growth of underyearling fish held in aquariums and fed at various consumption levels. Juvenile coho experiencing the cooler temperatures of the control stream demonstrated generally better growth rates than did those that experienced the warmer temperatures of the clearcut stream. The reduced maintenance requirements in the control experiment indicated a reduced basal metabolic demand, which allowed for a greater portion of the food consumed to be utilized for growth. This was particularly true at low levels of consumption. Growth rates of juvenile coho salmon in the wild state were found to be higher in the logged stream as compared to the unlogged stream. This difference from the experimental results is thought to be due to a change in availability and abundance of food. There was a marked decrease in the cutthroat trout population in the clearcut stream, which may have reduced competition for the coho salmon. Increased exposure of the stream to solar radiation also may have permitted en increase in primary production essential for small organisms upon which the juvenile coho feed. There was no apparent influence of infestation by salmon poisoning fluke on the condition of the juvenile coho.
Genre Thesis/Dissertation
Topic Coho salmon
Identifier http://hdl.handle.net/1957/22574

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