Calaveras River Juvenile Migration Monitoring continued at Shelton Road (RM 28) and a total of 9 O. mykiss were captured, increasing the season total to 84.

No Chinook salmon were captured during this reporting period. The season total remains at two.

Instantaneous temperature recorded at the trap ranged from 41.7�F to 46.4�F, and turbidity ranged from 1.05 NTU to 8.22 NTU. During the reporting period, daily average combined flow from New Hogan Dam (NHG) and Cosgrove Creek (COS) fluctuated between 30 cfs and 42 cfs, and at Bellota (MRS) flow fluctuated between 14 cfs and 103 cfs (Figure 1).

Stanislaus River rotary screw trap monitoring at Oakdale (RM 40) continued during the reporting period and a total of 10,691 Chinook salmon were captured, increasing the season total to 12,964. Average forklengths and weights of all Chinook salmon are provided in Table 2. Most of the fish measured were fry (n = 879), but parr (n=3) and smolt (n=16) were also observed, including 15 Chinook salmon greater than 100 mm.

 

A total of 15 O. mykiss were captured during the reporting period and rated as silvery parr (n=5) and smolt (n=10), increasing the season total to 18. 

Table 2. Biosampling data for Chinook salmon and O. mykiss captured and measured at Oakdale between January 7 and January 20, 2013. Parentheses indicate range.

 

Instantaneous temperature taken at the trap ranged from 44.2�F to 48.7�F, and turbidity ranged from 1.18 NTU to 14.28 NTU. Daily average flow at Goodwin Dam (GDW) ranged from 278 cfs to 285 cfs, and flow ranged from 308 cfs to 506 cfs at Ripon (RIP) (Figure 2).

 

Three trap efficiency evaluations were conducted during the reporting period with naturally spawned juvenile Chinook salmon fry marked caudal fin green (CFG). The preliminary estimated capture efficiencies were 10.6%, 13.2% and 21.5% at flows of 283 cfs, 283 cfs and 279 cfs, respectively (Table 3).

 

Table 3. Trap efficiency tests conducted at Oakdale between January 7 and January 20, 2013.

   

Figure 2. Daily Chinook salmon catch at Oakdale and Stanislaus River flow recorded at Goodwin Dam (GDW) and Ripon (RIP) in 2013.

 

Stanislaus River rotary screw trap monitoring at Caswell Memorial State Park (RM 9) continued with a total of 12 Chinook salmon fry were captured, increasing the season total to 62 fry and 1 yearling. No O. mykiss were captured. Season total remains at one.  

 

Instantaneous temperature recorded at the trap ranged from 43.3�F to 50.4�F, and instantaneous turbidity ranged from 1.51 NTU to 31.70 NTU. Instantaneous dissolved oxygen measured at the trap ranged from 11.03 mg/L to 15.95 mg/L.

Tuolumne River rotary screw trap monitoring at Waterford (RM 30) continued during the reporting period and a total of 690 Chinook salmon were captured. Average forklengths and weights of all Chinook salmon are provided in Table 4. All of the fish measured were fry (n = 551). No Chinook salmon were captured prior to the reporting period.  

Instantaneous temperature taken at the trap ranged from 43.1�F to 48.5�F, and turbidity ranged from 0.63 NTU to 6.84 NTU. Daily average flow at La Grange (LGN) was stable between 173 cfs and 176 cfs (Figure 3).

Two trap efficiency evaluations were conducted during the reporting period with naturally spawned juvenile Chinook salmon fry marked caudal fin orange (CFO). The preliminary estimated capture efficiencies were 22.2% and 13.2% at a flow of 176 cfs (Table 5).

 

Figure 3. Daily Chinook salmon catch at Waterford and Tuolumne River flow recorded at La Grange (LGN) between January 1 and January 20, 2013.

  

Tuolumne River rotary screw trap monitoring at Grayson (RM 5) continued during the reporting period and 1 Chinook salmon fry (30 mm) was captured. No Chinook salmon were captured prior to the reporting period.

 

Instantaneous temperature taken at the trap ranged from 41.7�F to 48.5�F, and turbidity ranged from 0.54 NTU to 33.70 NTU. Daily average flow at Modesto (MOD) fluctuated during the reporting period due to a couple freshet events, ranging between 210 cfs and 518 cfs (Figure 4).

  

No trap efficiency evaluations were conducted during the reporting period.

 

   

Figure 4. Daily Chinook salmon catch at Grayson and Tuolumne River flow recorded at Modesto (MOD) between January 1 and January 20, 2013.

Mokelumne River rotary screw trap monitoring at Vino Farms (RM 54) continued sampling intermittently during the reporting period. A total of 4,272 juvenile Chinook salmon were captured, increasing the season total to 5,008.

  

Average daily flow from Camanche Reservoir (CMN) ranged from 256 cfs to 500 cfs (Figure 5). Instantaneous temperature ranged between 46.0�F and 49.6�F, and instantaneous turbidity ranged between 1.32 NTU and 3.40 NTU.

 

Figure 5. Daily juvenile Chinook catches at Vino Farms and Mokelumne River flow recorded at Camanche Reservoir (CMN), between December 1, 2012, and January 20, 2013.

Mokelumne River rotary screw trap monitoring at Golf (RM 38) began on January 7 and sampling was intermittent during the reporting period. A total of 86 juvenile Chinook salmon were captured.

Average daily flow from Woodbridge Dam (WBR) ranged from 140 cfs to 346 cfs (Figure 6). Instantaneous temperature ranged between 46.8�F and 49.5�F, and instantaneous turbidity ranged between 1.70 NTU and 4.45 NTU.

 

Figure 6. Daily juvenile Chinook catches at Golf and Mokelumne River flow recorded at Woodbridge Dam (WBR), between December 15, 2012, and January 20, 2013. 

 

Between January 7 and January 20 one Chinook salmon was detected by the Vaki Riverwatcher as they passed upstream of the Stanislaus River weir.The total passage to-date of 7,043 is the highest observed at the Stanislaus weir since monitoring began in 2003 (Figure 5; Table 6). Daily passage ranged between 0 and 1 Chinook salmon (Figure 7).

 

Instantaneous water temperature measured at the weir ranged between 44.9˚F and 49.2˚F, and daily average water temperature at Ripon (RPN; RM 15) ranged between 44.7˚F and 49.2˚F (Figure 8). Instantaneous turbidity ranged between 2.0 NTU and 37.4 NTU (Figure 9). Instantaneous dissolved oxygen at the weir ranged between 10.85 mg/L and 13.47 mg/L, and daily average dissolved oxygen at Ripon (RPN; RM 15) ranged from 9.44 mg/L to 11.20 mg/L (Figure 10).

 

Daily average flows in the Stanislaus River at Goodwin Dam (GDW; RM 58) ranged from 278 cfs to 285 cfs. Flows at Ripon (RIP; RM 15) ranged from 308 cfs to 506 cfs. Note: flows downstream of Goodwin Dam may differ from dam releases due to irrigation, precipitation and other factors.

 

Table 6. Annual fall-run Chinook passage at the Stanislaus River weir prior to January 20, 2003-2012.

 

 

Figure 8. Daily upstream Chinook passage recorded at the Stanislaus River weir in relation to instantaneous water temperature recorded at the weir, and daily average water temperature recorded in the Stanislaus River at Ripon (RPN), and in the San Joaquin River at Vernalis (VER), Mossdale (MSD) and Rough & Ready (RRI) in 2012/13. 

Fall-run Chinook salmon returning to the Mokelumne are counted annually by East Bay Municipal Utility District (EBMUD) as they ascend the fish ladder at Woodbridge Dam. A total of 3 Chinook salmon were observed passing upstream of the dam before monitoring ended in mid-January, increasing the total for the season to 12,091. Daily passage ranged between 0 and 1 Chinook salmon (Figure 15).

Figure 15. Daily upstream Chinook passage recorded at the Woodbridge Dam fish ladder in relation to daily average flows (cfs) recorded in the Mokelumne River at Camanche Reservoir (CMN) in 2012 and 2013.  

Annual carcass surveys conducted by CDFW ended on the Tuolumne River during the week of December 31 and on the Stanislaus and Merced rivers during the week of January 7. The number of live fish and redds observed on all rivers continued to be low during the final week of survey. Three live fish were observed on the Stanislaus River, 0 on the Tuolumne River and 3 on the Merced River. Three redds were observed on the Stanislaus, 29 on the Tuolumne and 0 on the Merced River.