This study examined features of deep pool (>0.8 m mean depth) used by
adult summer steelhead in Steamboat Creek (1991-1992). Steamboat Creek had
a heterogenous thermal profile, with some segments exceeding preferred
temperature of steelhead. Deep pools were scarce (4% of the total habitat units)
and 39% of them were identified as cool pools (mean bottom water temperature [less than or equal to]
19°C). Adult summer steelhead were found primarily in deep pools, avoiding
other habitats (glides, riffles) and even cold but shallow tributary junctions. Use of
odds ratio showed that use of cool pools use was estimated to be 11 times greater
than the odds of the use of warm pools (P <0.001). Discriminant analysis identified
mean bottom pool water temperature, riparian forest at the pool bank, proportion
of large boulders, maximum length and mean depth as the best subset of variables
that accounted for differences between pools occupied and not occupied by adult
steelhead. A total of 69% of the variation was explained by differences in used and
not used groups. Classification accuracy was 89%. Canton Creek, a tributary of Steamboat Creek, were tested as validation site for the derived model, observing
that the classification function performed moderately, achieving a hit-ratio of 0.7.
Results of the study showed that, since bottom pool temperature was a major
factor but other ecological factors were also relevant, an integrated framework
would be required in determining pool used by this species. Moderate success of
the predictive model suggests that managers will want to check it before applying
in other basins. / Graduation date: 1995
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26769 |
| Date | 14 November 1994 |
| Creators | Baigun, Claudio Rafael Mariano |
| Contributors | Sedell, James R. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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