February 18 through March 9, 2008; Report No. 2

Figure 1. Chinook salmon catch at Waterford versus flow at La Grange (LGN).

One trap efficiency test was conducted at Waterford using natural Chinook captured from the trap with a resulting efficiency of 14%. 

Table 1. Trap efficiency test(s) conducted at Waterford between February 18 and March 9, 2008.

Instantaneous water temperature taken at the Waterford trap ranged between 51 °F and 55 °F and turbidity ranged from 1.4 NTU to 93.8 NTU. Daily average flow at La Grange ranged between 162 cfs and 179 cfs.

Grayson:

The trap sampled continuously between February 18 and March 9. A total of 105 juvenile Chinook salmon were captured between January 28 and February 17 increasing the season total to 131. Daily catch ranged from zero to 74 Chinook (Figure 2). Average forklength was 42 mm and ranged from 35 mm to 117 mm. Average weight was 1.5 g and ranged from 0.3 g to 17.4 g.

One 200 mm (78.3 g) O. mykiss smolt was captured in the rotary screw traps during this sampling period.

Figure 2. Chinook salmon catch at Grayson versus flow at Modesto (MOD).

One trap efficiency test was conducted at Grayson using natural Chinook captured from the trap with a resulting efficiency of 7%.

Table 2. Trap efficiency test(s) conducted at Grayson between February 18 and March 9, 2008.

Instantaneous temperature taken at the trap ranged between 52 °F and 59 °F, and turbidity ranged from 1.7 NTU to 67 NTU.  Daily average flow at Modesto (MOD) fluctuated between 277 cfs and 1,009 cfs.