Description: The second study year encompassed similar activities to the first, with some modification. In terms of otolith marking, all spring chinook at each facility were marked by a series of scheduled incubation water depressions. Modifications to our work plan included a somewhat later initiation of otolith marking, a shortening of cold water exposure duration for Cowlitz fish at the alevin stage, and the use of on-station personnel for conducting actual water manipulations for otolith marking. Protocols for efficient computerized collection of otolith band data were established and exploratory data collections initiated. Most of this was aimed at documentation of variability in the induced otolith pattern as a result of measurement technique and inherent biological variation in growth rates of individual otoliths. When fish has reached their appropriate size, Coded-Wire Tags were applied in specific proportions to untagged fish at each hatchery, and all untagged fish were electronically counted. Separate tag codes were applied to groups representing various rearing or release strategies at each hatchery. 11 refs., 3 tabs.
Date: September 1, 1991
Creator: Blankenship, H. Lee & Volk, Eric
Partner: UNT Libraries Government Documents Department