Aquatic Habitat in Oregon Coastal Streams: Winter, 1999-2001

Identification Information

Citation

Originator: Jennifer Bock, Kim Jones, Rebecca Flitcroft, Jeffrey W. Snyder

Publish Date: September 30, 2004

Online Link: https://nrimp.dfw.state.or.us/crl/Reports/AI/OPSW-ODFW%202004-05%20web.pdf

BPA Project #:

Contact Information

Agency: Oregon Department of Fish and Wildlife

Name: Charlie Stein

Job Position: Project Leader

Telephone: (541) 757- 5127

E-Mail Address: charlie.stein@oregonstate.edu

Description

Abstract: We compared summer and winter aquatic habitat conditions to determine patterns of seasonal habitat dynamics for coho salmon (Oncorhynchus kisutch). Winter sites corresponded to summer sites, facilitating a direct comparison between seasons on a site specific and regional scale. The data sets included 128 sites selected from the Oregon Plan habitat sites (OPHS) surveyed in the summers of 1999 and 2000 and surveyed again in the winters of 2000 and 2001. We found significant differences among geomorphic, hydrologic, and physical habitat variables measured along identical reaches in streams between winter and summer. Increases in water volume corresponded with increased deep pool density, secondary channel habitats, and wood density. These differences highlight the importance of high winter flows in terms of their contribution towards essential habitat for coho survival and reproduction. Differences among habitat variables from consecutive winters were minimal, indicating that any differences in habitat variables may be a result of variation in annual precipitation. Moreover, minimal differences in habitat variables were observed between Basin and OPHS surveys, also leading to the suggestion that OPHS surveys, conducted during the summer may provide important baseline information on habitat variables within and among watersheds. Habitat quality, as measured by benchmarks, was shown to be independent of land ownership but not independent of monitoring area. This investigation allowed us to quantify seasonal changes in summer-to-winter habitat dynamics in coastal Oregon streams. Future research could involve the addition of juvenile salmon surveys with habitat surveys to determine any significant associations between fish density and habitat quality. Furthermore, habitat variables measured during the summer might be used to determine winter habitat conditions (i.e. and thus quality), after accounting for variation in annual precipitation. Attribute means and estimates of variation, measured at identical sites in summer and winter over the long-term, may be beneficial when linking summer to winter habitat variables and ultimately to fish density estimates, thereby increasing sample size and predictability.

Purpose:

Time Period of Content: 1999-2001

Geographic Extent: Oregon Coastal Basins

Status: Final

Use Constraints:

Format: PDF File

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Data Information

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Entity and Attribute Information

Attributes Description: Field attribute information is available in the attached file(s).

Is a physical copy maintained for reference at Headquarters? Yes