Record Details
Field | Value |
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Title | Some effects of dissolved oxygen concentration on feeding, growth and bioenergetics of juvenile Coho salmon |
Names |
Thatcher, T. O.
(creator) Warren, Charles E. (advisor) |
Date Issued | 1974-12-10 (iso8601) |
Note | Graduation date: 1975 |
Abstract | The effects of three levels of dissolved oxygen (8, 5 and 3 mg/l) upon the feeding, growth and bioenergetics of juvenile coho salmon, Oncorhynchus kisutch (Walbaum), were determined in laboratory studies. Experiments with individual fish were conducted during the summer, fall and spring to measure rates of food consumption, standard metabolism, waste production, activity-specific dynamic action, and growth. House fly larvae were fed to the young salmon and the temperature was kept constant year-round at 15 C. The results indicated that differences due to the dissolved oxygen concentration were not great. Food consumption rate and the slope of growth rate curves were reduced only at 3 mg /I dissolved oxygen and only at near maximum food consumption rates which appear to be higher than juvenile coho salmon generally encounter in nature. However, normal competition for food and space in stream life (not present in these experiments) would be expected to curtail feeding in naturally occurring populations of juvenile cohos exposed to dissolved oxygen levels near 3 mg/l. Energy budgets were constructed from caloric determinations of the various uses made of the energy in the consumed food. These revealed that the reduced slope of the growth curve exhibited by 3 mg/l fish at near maximum feeding levels was due to sharp increases in energy requirements for activity-specific dynamic action. These energy budgets also offered the explanation that the greater loss of weight by the starved juvenile cohos kept at 8 mg /l dissolved oxygen (as compared to those kept at 3 and 5 mg/I) was due to their greater activity. Juvenile cohos kept at 5 mg/l dissolved oxygen in these studies grew at least as well as those at 8 mg /l. Again, however, this was considered to be an artifact of this experimental procedure. Fish reported upon here were not required to expend energy in competition for food and space as are those living in nature. |
Genre | Thesis/Dissertation |
Topic | Coho salmon |
Identifier | http://hdl.handle.net/1957/45601 |