Defining the Physiochemical, Biological and Habitat Requirements for the Upper Extant of Oncorhynchus mykiss Distribution

Authors

Emily Powers

Document Type

Article

Abstract

The distribution of rainbow trout is strongly influenced by their habitat. As climatic conditions change, the distribution of rainbow trout populations will change along with them. The objective of this study was to identify the particular habitat parameters that rainbow trout select for in this lotic system and to specifically assess how this relates to the upper extant of their distribution. By assessing the distribution of the upper extant specifically, future research may be conducted to better assess climatic changes on a small and/or large scale basis. A 9,000 m section of the Clearwater River was used as the study site. Hook-and-line method was used to catch all rainbow trout throughout this reach and was used to assess the upper extant of the trout population’s distribution. Available and used habitat parameters including temperature, dissolved oxygen, depth, width, stream velocity, and substrate size were assessed two times per week for three months. A t-test, displaying 95% confidence, was used to compare available habitat to habitat used by rainbow trout. T-test results indicated that temperature (p < 0.001), depth (p = 0.029), and width (p = 0.036) were habitat parameters that rainbow trout selected for. Trout resided farther upstream in the spring when river temperatures were cooler and depths deeper due to flooding conditions from snow melt. As temperatures increased, trout moved downstream to cooler water. While this trend is inconsistent with the River Continuum Concept, which explains physical, chemical, and biological patterns for north to south flowing rivers, the Clearwater River flows south to north and therefore may have extensive differences. As climatic conditions change, especially as temperatures increase, the distribution of trout will change also.

Publication Date

2014

Comments

Faculty sponsor: Dr. Andrew Hafs, Department of Biology, Aquatic Biology Program

Recommended Citation

Powers, Emily, "Defining the Physiochemical, Biological and Habitat Requirements for the Upper Extant of Oncorhynchus mykiss Distribution" (2014). Journal of Earth and Life Science. 48.
https://pines.bemidjistate.edu/j-earth-life-sci/48