The Calaveras River rotary screw trap at Shelton Road (RM 28) was operated eleven

Figure 1. O. mykiss captured in the Calaveras River rotary screw trap at Shelton Rd.

days between May 23 and June 19 and a total of 63 O. mykiss were captured, increasing the season total to 726 (Figure 1). Of the O. mykiss captured, 54 were YOY (>100 mm) and were either rated as parr (n=25) or silvery parr (n=29), and nine were Age 1+ (100-299 mm), rated as silvery parr (n=8) or smolt (n=1). Average forklengths and weights are provided for the O. mykiss in Table 1.

No Chinook salmon have been captured this season.

Instantaneous temperature recorded at the trap ranged from 52.8�F to 57.9�F, and turbidity ranged from 0.57 NTU to 7.20 NTU. Daily average combined flow from New Hogan Dam (NHG) and Cosgrove Creek (COS) fluctuated between 105 cfs and 279 cfs, and at Bellota (MRS) flow fluctuated between 28 cfs and 123 cfs.

No trap efficiency experiments were conducted during the reporting period. 

The Stanislaus River rotary screw trap at Oakdale (RM 40) sampled continuously during the reporting period. A total of 51 juvenile Chinook salmon were captured, bringing the season total to 42,467. Daily catch of Chinook salmon ranged between zero and nine individuals. Average forklengths and weights of Chinook salmon are provided in Table 2 for the 49 Chinook that were measured. All measured Chinook were smolts (n=49).

No O. mykiss were captured during the reporting period. The season total remains at 21.

Table 2. Biosampling data for Chinook salmon and O. mykiss captured and measured at Oakdale between May 23 and June 19, 2011.

Instantaneous temperature recorded at the trap ranged from 50.3�F to 53.6�F, and turbidity ranged from 0.32 NTU to 4.87 NTU (Figure 4). Daily average flow at Goodwin Dam (GDW) increased from 1,510 cfs and 2,070 cfs, and flow at Ripon (RIP) ranged from 1,539 cfs to 2,071 cfs (Figure 3).

No trap efficiency experiments were conducted during the reporting period.

Figure 3. Daily Chinook salmon catch at Oakdale, and Stanislaus River flow recorded at Goodwin Dam (GDW) and Ripon (RIP) in 2011.

Figure 4. Daily Chinook salmon catch at Oakdale in relation to instantaneous turbidity recorded at the trap in 2011.

The Stanislaus River rotary screw trap at Caswell State Park (RM 8) sampled continuously during the reporting period and a total of 45 juvenile Chinook salmon were captured, increasing the season total to 594. Daily catch ranged between zero and eight Chinook salmon (Figure 5).

One O. mykiss was captured during the reporting period increasing the season total to two.

No trap efficiency experiments were conducted during the reporting period.

Instantaneous temperature recorded at the trap ranged from 54.3�F and 59.5�F, and turbidity ranged from 2.04 NTU to 4.72 NTU. Daily average flow at Ripon (RIP) ranged from to 1,539 cfs to 2,071 cfs.

Figure 5. Daily Chinook salmon catch at Caswell, and Stanislaus River flow recorded at Ripon (RIP) in 2011.

Figure 6. Processing the Tuolumne River rotary screw trap at Waterford.

The Tuolumne River rotary screw trap at Waterford (RM 30) operated continuously during the reporting period (Figure 6). A total of 146 juvenile Chinook salmon were captured bringing the season total to 4,368. Daily catch ranged between zero and eighteen Chinook. Average forklengths and weights are provided in Table 3 for 140 of the Chinook salmon. The majority of the measured Chinook were smolts (n=138), but parr (n=2) were also recorded.

No O. mykiss were captured during this reporting period.

Table 3. Biosampling data for Chinook salmon captured and measured at Waterford between May 23 and June 19, 2011. Parentheses indicate range.

Instantaneous temperature taken at the trap ranged from 50.5�F to 55.2�F, and turbidity ranged from 0.41 NTU to 2.36 NTU. Daily average flow at La Grange (LGN) fluctuated from 2,970 cfs to 7,020 cfs (Figure 7).

No trap efficiency experiments were conducted during the reporting period.

Figure 7. Daily Chinook salmon catch at Waterford, and Tuolumne River flow recorded at La Grange (LGN) and Modesto (MOD) between December 1, 2010, and June 19, 2011.

Figure 8. Chinook salmon captured in the Tuolumne River rotary screw trap at Grayson.

The Tuolumne River rotary screw traps at Grayson (RM 5) sampled continuously during the reporting period and catch at Grayson continues to be higher than during the previous two years. A total of 62 Chinook salmon were captured, bringing the season total to 1,639 (Figure 8). All measured Chinook salmon were smolts (n=61), and average forklengths and weights are provided in Table 4.

No O. mykiss were captured during this reporting period.

Table 4. Biosampling data for Chinook salmon captured and measured at Grayson between May 23 and June 19, 2011. Parentheses indicate range.

Instantaneous temperature taken at the trap ranged from 52.8�F to 60.2�F, and turbidity ranged from 0.71 NTU to 3.68 NTU. Daily average flow at Modesto (MOD) fluctuated from 3,240 cfs to 6,400 cfs (Figure 9).

No trap efficiency experiments were conducted during the reporting period.

Figure 9. Daily Chinook salmon catch at Grayson, and Tuolumne River flow recorded at La Grange (LGN) and Modesto (MOD) between January 1 and June 19, 2011.

The Mokelumne River rotary screw trap at Vino Farms (RM 54) was sampled intermittently, and a total of 179 juvenile Chinook salmon were captured during the reporting period, bringing the season total to 29,801.

Average daily flow from Camanche Reservoir (CMN) fluctuated during the reporting period ranging from 1,403 cfs to 2,051 cfs (Figure 10). Instantaneous temperature ranged from 54.5�F to 58.1�F, and instantaneous turbidity ranged between 1.81 NTU and 4.49 NTU.

A total of 56 O. mykiss were captured during the reporting period, increasing the season total to 108.

Flow in the Merced River at Cressy (CRS; RM 52) fluctuated between 662 cfs and 3,443 cfs during reporting period. Flow at Stevinson (MST; RM 5) fluctuated between 790 cfs and 2,332 cfs (Figure 13). Water temperature in the Merced River ranged from 54.9�F to 67.1�F at Cressy, and from 56.5�F to 71.3�F at Stevinson (Figure 14).

The California Department of Fish and Game continued Kodiak trawling on the San Joaquin River near Mossdale (i.e. the Mossdale Trawl). Twenty days of trawling (with between 7 and 15 tows per day) were conducted between May 23 and June 19. A total of 1,647 naturally spawned juvenile Chinook salmon were captured during the reporting period, increasing the season total to 3,126. A total 247 hatchery origin Chinook salmon were also captured during the reporting period. Daily catch ranged between 7 and 247 Chinook (Figure 15).

Vernalis Adaptive Management Plan (VAMP) team members concluded implanting HTI LD acoustic tags in O. mykiss during the reporting period for the six-year study. A total of five release groups of 480 acoustically tagged O. mykiss were conducted.

VAMP team members concluded implanting HTI LM acoustic tags in Chinook salmon and a total of five release groups of 480 Chinook salmon were conducted.

During the reporting period, flow in the San Joaquin River at Vernalis fluctuated from 9,636 cfs to 11,333 cfs (Figure 16). Water temperature in the San Joaquin River ranged from 57.5�F to 63.7�F at Vernalis, from 58.9�F to 67.4�F at Mossdale, and from 59.9�F to 67.7�F at Rough 'n Ready Island (Figure 17). Average daily dissolved oxygen (DO) in the San Joaquin River fluctuated from 8.5 mg/L to 9.3 mg/L in the deep-water ship channel (measured at Rough 'n Ready Island), and from 8.6 mg/L to 9.5 mg/L at Mossdale (Figure 18).

during this period increased from 2,138 cfs to 9,991 cfs.