2006 was the seventh consecutive year of rotary trapping on the Shasta and Scott rivers. The goals of the project were to determine emigration abundance and timing of all age classes of juvenile salmonids emigrating from the Shasta and Scott rivers between early February and mid July 2006 and to investigate the relationships between instream conditions and emigration patterns of juvenile salmonids.
We determined trap efficiencies for all age classes of salmonids in the catch and calculated weekly production estimates for each age class. We estimated the weekly mean fork length at age of salmonids in the catch from a measured sub-sample. The number of 0+ Chinook (Oncorhynchus tshawytscha) produced was the lowest for the period of record for both the Shasta and the Scott rivers. We estimated that only 3.57% and 2.68% of the previous five year average were produced respectively. We believe this is due to high flows in December 2005 and the resultant destruction of redds. We estimated the number of coho (Oncorhynchus kisutch) smolts produced per returning adult and the smolt to adult survival for Shasta River coho, brood years 2001 through 2004. We projected a downward trend in the number of returning adult