Juvenile salmonid rotary screw trap data from Battle and Clear Creeks, Shasta and Tehama Counties, California.

Clear Creek The U.S. Fish and Wildlife Service continued its juvenile salmonid monitoring project in Clear Creek, Shasta County, California, that began in December 1998 using a rotary screw trap (RST) located at river mile (RM) 1.7. This monitoring project has three primary objectives: (1) calculate annual juvenile passage indices for Chinook Salmon Oncorhynchus tshawytscha and Rainbow Trout/steelhead O. mykiss (we use the term O. mykiss to refer to both the stream resident (Rainbow Trout) and anadromous (steelhead) life histories because of the difficulties in differentiating the anadromous and resident forms in the field) for inter-year comparisons and analyses of the effectiveness of stream restoration activities; (2) obtain juvenile salmonid life history information including size, timing, and potential factors limiting survival; and (3) collect biological samples from juvenile salmonids. Chinook Salmon run classifications show that all Chinook Salmon runs known to the Sacramento River were captured; however, due to overlapping spawning times of spring-run and fall-run Chinook Salmon it was problematic to index the juvenile passage using only the RST at RM 1.7. Since 2003 a separation weir has been used to isolate adult spring-run Chinook Salmon from adult fall-run Chinook Salmon; therefore, a second RST was added above the weir at RM 8.4. Battle Creek The U.S. Fish and Wildlife Service continued its juvenile salmonid monitoring project in Battle Creek, Shasta and Tehama Counties, California, that began in December 1998 using a RST located at river mile (RM) 6.2. The upper Battle Creek RST objectives are to (1) calculate annual juvenile passage indices for spring-run, late-fall run, and winter-run Chinook Salmon; Rainbow Trout/steelhead O. mykiss (we use the term O. mykiss to refer to both the stream resident (Rainbow Trout) and anadromous (steelhead) life histories because of the difficulties in differentiating the anadromous and resident forms in the field); (