Juvenile Salmonid Growth Monitoring: Gird Creek, Russian River, California, 1994-2001

Juvenile abundance monitoring was conducted within "index zones". Each stream was divided into upper, middle and lower reaches, based on elevation, average gradient, and distance from the Russian River, and an index zone was select from surveys within each reach. Index zones were established during the first study year and surveyed for habitat condition. Each index zone was then broken down into habitat unit types (pool, riffle, glide), in which a unit is defined as a continuous portion of the stream of variable length, within which only one habitat type is present or is dominant. Juvenile abundance monitoring was conducted in selected units rather than the entire index zone. However, mapping is at the scale of index zone and the pooled results from units within each index zone are presented here.

Fish were sampled in selected units within each index zone by repeated passes through the unit with a beach seine. Salmonids were identified to species (steelhead, coho) and measured (fork length). In some years steelhead densities were too high to safely measure all samples. A representative subsample (reported here) was measured to establish length frequency estimates for each year class. Monitoring was conducted at the beginning (July) and end (October-November) of the summer dry period to enable estimation of juvenile growth rate.