Juvenile Salmonid Abundance Monitoring: Mark West Creek, Russian River, California, 1991-2001

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, with data for individual units included.

Fish were sampled in selected units within each index zone by repeated passes through the unit with a beach seine. All fish and other species (invertebrates, amphibians, reptiles, mammals) captured were identified to species, and the salmonids (steelhead, coho) were measured (fork length). Monitoring was conducted at the beginning (July) and end (October-November) of the summer dry period to enable estimation of percent retention within the sampling area over this critical time period, as well as inferences regarding spawning success and juvenile growth rate.

Mapping was conducted at the scale of index zone rather than habitat unit. Data for habitat zone is presented here without spatial data as supplemental information.