A Procedure to Estimate Changes in Fish Populations Caused by Changes in Stream Discharge

Publisher Website
Google Scholar
Abstract
A simple technique to estimate the relationship between fish populations and stream discharge was developed. It is based on measurements of cross-sectional areas of the stream, water depths and water velocities over a range of stream discharges. It weights these in accordance with frequency distributions of water depth and water velocity preferred by various life-history phases of coho salmon Oncorhynchus kisutch, chinook salmon O. tshawytscha and steelhead Salmo gairdneri. Changes in the absolute capacity of the stream to support fish are estimated from records of fish abundance at known discharges that are used to calibrate a scale showing changes in relative capacity. Quantitative estimates of changes in the relative capacity of a stream to support fish as a function of stream discharge determined by this technique are statistically correlated with predictions made by an established qualitative method and by various subjective assessments.

This publication has 0 references indexed in Scilit: