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Volume 2010/11, Issue 4
November 10, 2010
In This Issue
Stanislaus River Weir Monitoring
Stanislaus River Juvenile Migration Monitoring
Tuolumne River Weir Monitoring
Merced River Conditions
San Joaquin Basin Escapement Surveys
Mokelumne River Woodbridge Dam Fish Ladder Monitoring
San Joaquin Conditions
Delta Exports
events

Stanislaus River Salmon Festival:
Nov. 14

VAMP Biology Technical Team Meeting:
Nov. 15

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FISHBIO



Columbia River DART

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field notes
O. mykiss
  Photo by FISHBIO.
 
Key Highlights


Stanislaus River Weir Monitoring continued during the reporting period, and 679 Chinook salmon have been counted as of October 31.

Stanislaus River Juvenile Migration Monitoring was initiated immediately after installation of the rotary screw trap at Oakdale (RM 40) on October 11. A total of three Chinook salmon, and numerous black bass were captured during the reporting period.

Tuolumne River Weir Monitoring continued during the reporting period, and 487 Chinook salmon have been counted as of October 31.

Merced River. As of October 28, no Chinook salmon have been spawned at the Merced River Fish Facility

San Joaquin Basin Escapement Surveys. Annual carcass surveys conducted by CDFG continued during the week of October 25. Seventy-one Chinook were observed on the Tuolumne River, forty-nine on the Stanislaus River and eight on the Merced River.

Mokelumne River Woodbridge Dam Fish Ladder Monitoring. As of October 31 a total of 4,616 Chinook salmon passed upstream of the dam.

San Joaquin River Conditions. San Joaquin River flows at Vernalis ranged between 1,861 cfs and 3,234 cfs. Water temperatures in the San Joaquin River ranged between 57.7F and 67.5F. Average daily dissolved oxygen (DO) in the San Joaquin River fluctuated between 7.9 mg/L and 9.1 mg/L at Mossdale, and between 6.0 mg/L and 7.5 mg/L at Rough 'n Ready.

Delta Exports.Combined total exports (state and federal pumps) fluctuated during the reporting period and ranged from 7,816 cfs to 10,078 cfs.



 
2010/11 Stanislaus River Weir Monitoring


Stanislaus River Weir
Figure 1. Stanislaus River weir.


Between October 11 and October 31 a total of 461 fall-run Chinook salmon were detected by the Vaki Riverwatcher as they passed upstream of the Stanislaus River weir, increasing the season total to 679 (Figures 1 and 2). Daily passage ranged from 7 to 50 Chinook salmon (Figure 4). The number of Chinook salmon passages observed so far this year is consistent with passages observed during this period in previous years (Table 1; Figure 3).



Sockeye/Kokanee in the Stanislaus River
Figure 2. Rare sockeye/kokanee footage in the lower Stanislaus River. Read more on our Field Notes page.

Instantaneous water temperature measured at the weir ranged between 53.7˚F and 65.6˚F, and daily average water temperature at Ripon (RPN; RM 15) ranged between 56.1˚F and

67.2˚F (Figure 5). Instantaneous turbidity ranged between 0.60 NTU and 6.11 NTU (Figure 6). Instantaneous dissolved oxygen at the weir ranged between 8.32 mg/L and 9.51 mg/L, and daily average dissolved oxygen at Ripon (RPN; RM 15) ranged from 9.08 mg/L to 10.20 mg/L (Figure 7).


Daily average flows in the Stanislaus River at Goodwin Dam (GDW; RM 58) fluctuated between 203 cfs and 1,503 cfs due to regulated pulse flows. Similarly, flows at Ripon (RIP; RM 15) fluctuated between 209 cfs and 1,341 cfs (Figure 4). Note: flows downstream of Goodwin Dam may differ from dam releases due to irrigation, precipitation and other factors.

 

Table 1. Annual fall-run Chinook passage prior to October 31, 2003-2010.
YTD Passage Table
Cummulative Chinook passage 2003-2010

Figure 3. Cumulative passage of fall-run Chinook salmon recorded at the Stanislaus River weir from 2003-2010.



Flow and Catch

Figure 4. Daily upstream Chinook passage at the Stanislaus River weir in relation to daily average flows (cfs) recorded in the Stanislaus River at Goodwin (GDW) and Ripon (RIP), and in the San Joaquin River at Vernalis (VNS) in 2010.

 
 
Temp and Catch

Figure 5. 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  2010.

turbidity and catch

Figure 6. Daily upstream Chinook passage at the Stanislaus River weir in relation to instantaneous turbidity recorded at the weir in 2010.


Dissolved Oxygen and Catch
Figure 7. Daily upstream Chinook passage at the Stanislaus River weir in relation to instantaneous dissolved oxygen recorded at the weir, and daily average dissolved oxygen recorded in the Stanislaus River at Ripon (RPN), and in the San Joaquin River at Mossdale (MSD) and Rough & Ready (RRI) in 2010.

 
2010/11 Stanislaus River Juvenile Migration Monitoring

 
Oakdale Rotary Screw Trap
Figure 8. Stanislaus River rotary screw trap at Oakdale.

The Stanislaus River rotary screw trap at Oakdale (RM 40)was installed to monitor potential yearling Chinook migration during the fall pulse flow occurring from October 14 to October 29 (Figure 8). The trap operated continuously from October 11 and captured only three Chinook salmon (Figure 9). Two Oncorhynchus mykiss were also captured and measurements were collected for one of these individuals (Table 2).






Flow and Catch

Figure 9. Daily Chinook salmon catch at Oakdale, and Stanislaus River flow recorded at Goodwin Dam (GDW) and Ripon (RIP) in 2010.

 

Table 2. Biosampling data for Chinook salmon and O. mykiss captured and measured at Oakdale between October 11 and November 1, 2010.


Salmonids Table

 


Black Bass
Figure 10. Black bass captured in the Oakdale rotary screw trap. Read more on black bass captured at Oakdale on our Field Notes page.

 

 Rotary screw trap catch during this sampling period was dominated by black bass (genus Micropterus). A total of 366 small black bass were captured during the sampling period, including 274 that were positively identified as largemouth bass. The peak catch of black bass occurred just after the fall pulse flow began (Figure 10). Since the rotary screw trap was installed earlier than usual, historical data are not available for comparison.


Instantaneous temperature taken at the trap ranged from 52.7F to 64.4F, and turbidity ranged from 0.49 NTU to 3.31 NTU. Daily average flow at Goodwin Dam (GDW) ranged between 200 cfs and 1,503 cfs, and flows at Ripon (RIP) ranged between 209 cfs and 1,341 cfs (Figure 6).


No trap efficiency experiments were conducted during this reporting period.

 




2010/10 Tuolumne River Weir Monitoring


Tuolumne River weir
Figure 11. Tuolumne River weir.

Between October 11 and October 31 a total of 324 Chinook salmon were detected by the Vaki Riverwatcher as they passed upstream of the Tuolumne River weir, increasing the season total to 487 (Figures 11). Daily passage ranged from 3 to 26 Chinook (Figure 12 and 14). The number of Chinook passages observed so far this year has exceeded the total passage count observed last year (Table 3; Figure 13).

 

Chinook salmon in the Tuolumne River
Figure 12. Chinook salmon observed in the Tuolumne River.


 


Instantaneous water temperature measured at the weir ranged between 55.7˚F and 62.0˚F. Daily average water temperature at Modesto (MOD; RM 17) fluctuated between 57.2˚F and 61.2˚F (Figure 15). Instantaneous turbidity ranged between 0.41 NTU and 1.94 NTU (Figure 16), and instantaneous dissolved oxygen ranged between 7.47 mg/L and 9.37 mg/L (Figure 17).

 

Daily average flows in the Tuolumne River decreased from 858 cfs to 357 cfs at La Grange (LGN; RM 50) and from 968 cfs to 431 cfs at Modesto (MOD; RM 17) (Figure 18). Note: flows downstream of La Grange may be higher than dam releases due to accretion and Dry Creek inflow.

 

 

Table 3. Annual fall-run Chinook passage prior to October 31, 2009 and 2010.

Cummulative Chinook passage 2009-2010

Cummulative Chinook passage 2009-2010

Figure 13. Cumulative passage of fall-run Chinook salmon recorded at the Tuolumne River weir in 2009 and 2010.



Flow and Catch

Figure 14. Daily upstream Chinook passage at the Tuolumne River weir in relation to daily average flows (cfs) recorded in the Tuolumne River at La Grange (LGN) and Modesto (MOD), and in the San Joaquin River at Vernalis (VNS) in 2010.

 
Temp and Catch

Figure 15. Daily upstream Chinook passage at the Tuolumne River weir in relation to instantaneous water temperature recorded at the weir, and daily average water temperature recorded in the Tuolumne River at Modesto (MOD), and in the San Joaquin River at Vernalis (VER), Mossdale (MSD) and Rough & Ready (RRI) in 2010.

 
turbidity and catch

Figure 16. Daily upstream Chinook passage at the Tuolumne River weir in relation to instantaneous turbidity recorded at the weir in 2010.


Dissolved Oxygen and Catch

Figure 17. Daily upstream Chinook passage at the Tuolumne River weir in relation to instantaneous dissolved oxygen recorded at the weir, and daily average dissolved oxygen recorded in the San Joaquin River at Mossdale (MSD) and Rough & Ready (RRI) in 2010.


 
Merced River Conditions 

CDFG reports that no salmon have been spawned at Merced River Fish Facility as of October 28th. However, eight live Chinook salmon and two redds were observed during carcass surveys conducted the week of October 25th.

During the reporting period flows in the Merced River at Cressy (CRS; RM 52) fluctuated from 150 cfs to 842 cfs and at Stevinson (MST; RM 5) from 268 cfs to 1,159 cfs (Figure 18). Water temperatures in the Merced River decreased from 69.0F to 56.2F at Cressy and from 77.1F to 59.2F at Stevinson (Figure 19).

Flow 

Figure 18. Daily average flows (cfs) recorded in the Merced River at Cressy (CRS) and Stevinson (MST) in 2010.

Temperature

Figure 19. Daily average water temperatures (F) recorded in the Merced River at Cressy (CRS) and Stevinson (MST) in 2010.


 
San Joaquin Basin Escapement Surveys
 

Annual carcass surveys conducted by California Department of Fish and Game (CDFG) continued during the week of October 25. The largest number of live fish was observed on the Tuolumne River, with a peak live count thus far of 71 Chinook. Peak live counts on the Stanislaus River have increased to 49, while the Merced rivers counts are still low, at 8 Chinook.

Twenty-two redds were observed on both the Stanislaus and Tuolumne rivers and two redds have been recorded on the Merced River. Typically, the peak number of redds observed for the fall-run season occurs in mid- to late-November.


 
Mokelumne River Woodbridge Dam Fish Ladder Monitoring
 
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. As of October 31, a total of 4,616 Chinook have passed upstream of the dam this season (Figure 20).
 
 Chinook passage and flow
 

Figure 20. 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 2010. Note: Graph does not include fish observed before September 22.


 
San Joaquin Conditions
 
During the reporting period, flows generally increased in the San Joaquin River at Vernalis ranging from 1,861 cfs to 3,234 cfs (Figure 21). Water temperatures in the San Joaquin River decreased from 67.5F to 57.7F at Vernalis, from 68.6F to 58.4F at Mossdale, and from 71.2F to 61.8F at Rough 'n Ready Island (Figure 22). Average daily dissolved oxygen (DO) in the San Joaquin River fluctuated from 6.0 mg/L to 7.5 mg/L in the deep water ship channel (measured at Rough 'n Ready Island), and between 7.8 mg/L and 9.1 mg/L at Mossdale (Figure 23).

Flow 

Figure 21. San Joaquin River flows at Vernalis from October 1, 2009 through October 31, 2010.


Temperature 

Figure 22. San Joaquin River daily average water temperatures at Vernalis, Mossdale, and Rough 'n Ready from October 1, 2009 through October 31, 2010.

Dissolved Oxygen
 

Figure 23. San Joaquin daily average dissolved oxygen at Mossdale and Rough 'n Ready, from October 1, 2009 through October 31, 2010.



Delta Exports

Mean daily pumping at the C.W. Jones Pumping Plant (federal pumps previously known as Tracy Pumping Plant) remained relatively stable during the reporting period and fluctuated between 4,075 cfs and 4,156 cfs (Figure 24). Mean daily pumping at the Harvey O. Banks Pumping Plant (state pumps) ranged between 2,780 cfs and 5,976 cfs. Combined total exports (state and federal pumps) during this period ranged from 6,894 cfs to 10,078 cfs.

Exports

Figure 24. Daily exports at the state and federal pumping stations from October 1, 2009 through October 31, 2010.