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Volume 2008/09, Issue 16
September 1, 2009
In This Issue
2008/09 Calaveras River Juvenile Migration Monitoring
2009 Stanislaus River Juvenile Migration Monitoring
2009 Tuolumne River Juvenile Migration Monitoring
Merced River Juvenile Migration Monitoring
San Joaquin Conditions
Delta Exports
events
 
Sept 1: VAMP Biology Technical Team Meeting

Sept 10: Tuolumne River Technical Advisory Committee

links

FISHBIO

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field notes
Weir
Key Highlights
 
2008/09 Calaveras River Juvenile Migration Monitoring-Season Review. The Calaveras River rotary screw trap at Shelton Road (RM 28) sampled intermittently (typically 4 days on and 3 days off) from November 4, 2008 through July 10, 2009. The preliminary estimate of total O. mykiss abundance during 2008/09 is 11,746 O. mykiss young-of-year (YOY; <100 mm) comprised 78% of the total estimate and the remaining 22% were Age 1+ (≥100 mm).

2009 Stanislaus River Juvenile Migration Monitoring-Season Review. The Stanislaus River rotary screw trap at Oakdale (RM 40) sampled daily from January 7 through May 22; and sampled weekdays only between May 23 and July 2. The preliminary estimate of total juvenile Chinook abundance at Oakdale during 2009 is 182,376 which is a two-fold increase over the 2008 estimate and reflective of a similar increase in escapement between the two years.
 
The Stanislaus River rotary screw trap at Caswell (RM 8) sampled from January 12 through June 18. A preliminary estimate of abundance is not yet available.
 
2009 Tuolumne River Juvenile Migration Monitoring - Season Review. The Tuolumne River rotary screw trap at Waterford (RM 30) sampled daily from January 7 through June 9. The preliminary estimate of total juvenile Chinook abundance at Waterford is 37,714 which is an increase over 2008.

The Tuolumne River rotary screw trap at Grayson (RM 5) sampled daily from January 8 through June 11. The preliminary estimate of total juvenile Chinook abundance at Grayson was 4,420.
 
2009 Merced River Juvenile Migration Monitoring - Season Review. The Merced River rotary screw trap at Hatfield State Park (RM 2) sampled from March 30 to May 29. A preliminary estimate of abundance is not yet available.
 
San Joaquin River Conditions. Flow in the San Joaquin River at Vernalis fluctuated between 498 cfs and 787 cfs. Average daily water temperature in the San Joaquin River recorded at Vernalis, Mossdale, and Rough n' Ready Island ranged between 73.5F and 82.6F. Average daily dissolved oxygen in the San Joaquin River recorded at Mossdale and Rough n' Ready Island ranged between 5.4 mg/L and 17.8 mg/L.
 
Delta Exports. Combined (state and federal pumps) total exports fluctuated between 8,197 cfs and 11,440 cfs during the reporting period.
 
We encourage subscribers to contribute any relevant information for future issues of the newsletter (e.g., additional monitoring studies, announcements of upcoming meetings and events, etc). If you would like to contribute, please contact Chrissy Sonke.
 

 
2008/09 Calaveras River Juvenile Migration Monitoring 
 
The rotary screw trap at Shelton Road Bridge (RM 28) sampled intermittently (typically 4 days on and 3 days off) from November 4, 2008 through July 10, 2009. A total of 1,312 O. mykiss were captured during the sampling season. Daily catch ranged between zero and 76 O. mykiss. Daily O. mykiss abundance estimates ranged between 0 and 365 O. mykiss (Figure 1). The preliminary estimate of total O. mykiss abundance during 2008/09 is 11,746 O. mykiss. Young-of-year (<100 mm) comprised 78% of the total estimate and the remaining 22% were Age 1+ (≥100 mm). Total abundance was lower than 2008 but similar to 2007 (Table1, Figure 2). These estimates are preliminary and subject to change.

Chinook salmon were not captured in the Shelton Road trap this season.
 
Table 1. Summary of rotary screw trap sampling and estimated O. mykiss abundance at Shelton Road Bridge during 2007-2009.
 
  Calaveras sample table
Instantaneous temperature recorded at the trap ranged from 43F to 60F (average: 52F) and turbidity ranged from 0.1 NTU to 10.9 NTU (average: 1.7 NTU). Daily average flow on the Calaveras River ranged between 16 cfs and 238 cfs (average: 89 cfs) at New Hogan Dam (NHG), between zero cfs and 190 cfs (average: 5.1 cfs) at Cosgrove Creek (COS), and between zero and 692 cfs at Bellota (MRS).
 
Calaveras abundance
 
Figure 1. Daily O. mykiss abundance estimate at Shelton Road Bridge and Calaveras River flow recorded by the combination of New Hogan Dam and Cosgrove Creek (NHG + COS), 2008/09. 

 

 
2009 Stanislaus River Juvenile Migration Monitoring
 
The rotary screw trap at Oakdale (RM 40) sampled daily from January 7 through May 22; and sampled weekdays only between May 23 and July 2. A total of 60,432 Chinook were captured during the sampling season. Daily catch ranged between zero and 12,355 Chinook.

Thirteen trap efficiency experiments were conducted during the sampling season with observed efficiencies ranging from 2.6% to 51.4% at flows between 168 cfs and 707 cfs at Goodwin Dam. This information was used to calculate a preliminary abundance estimate of 182,376 juvenile Chinook salmon at Oakdale. Estimated abundance by lifestage is 110,009 fry (<50 mm), 35,916 parr (50-69 mm), and 36,451 smolts (≥70 mm) (Table 2). Daily Chinook abundance estimates ranged between 0 and 29,208 Chinook (Figure 2). These estimates are preliminary and subject to change.

Total estimated abundance of juvenile Chinook salmon at Oakdale during 2009 represents a two-fold increase over estimated abundance during 2008, and is reflective of a similar increase in adult abundance between the two years (Table 2). Adult abundance and subsequent juvenile production during 2007 was much higher than during both 2008 and 2009.
 
Table 2. Summary of rotary screw trap sampling and estimated juvenile Chinook salmon abundance at Oakdale during 2007-2009, and adult Chinook salmon abundance at the Stanislaus River Weir during 2006-2008.
 
Oakdale sampling table 

Oakdale abundance
  
 
Figure 2. Daily estimated juvenile Chinook salmon abundance at Oakdale and Stanislaus River flow at Goodwin Dam (GDW), 2009.
 
 
A total of 44 O. mykiss were captured at Oakdale during the sampling season. Measured O. mykiss consisted of 11 young-of-the-year (YOY; <100 mm), 29 Age 1+ (100-299 mm), and three adults (≥300 mm) (Figure 3).  O. mykiss catch during 2009 was similar to the average of total annual catches observed during 1998-2008 (Figure 4). O. mykiss abundance is not estimated at this site.

Instantaneous temperature recorded at the trap ranged from 44F to 62F (average: 53F) and turbidity ranged from 0.1 NTU to 23.2 NTU (average: 1.8 NTU). Daily average flow on the Stanislaus River ranged between 165 cfs and 1,312 cfs (average: 527 cfs) at Goodwin Dam (GDW), and between 206 cfs and 1,173 cfs (average: 517 cfs) at Ripon (RIP).

RBT scatter
 
Figure 3. Individual O. mykiss forklengths at Oakdale, 2009.

RBT lengths
 
Figure 4. Annual O. mykiss catch at Oakdale, 1998 to 2009.
 

The rotary screw trap at Caswell State Park (RM 8) sampled from January 12 through June 18. A preliminary estimate of juvenile Chinook salmon abundance is not yet available.


 
2009 Tuolumne River Juvenile Migration Monitoring 
 
The rotary screw trap near Waterford (RM 30) sampled daily from January 7 through June 9. A total of 3,725 Chinook salmon were captured during the sampling season. Daily catch ranged between zero and 565 Chinook.

Eleven trap efficiency experiments were conducted during the sampling season with observed efficiencies ranging from 2.8% to 27.0% at flows between 167 and 170 cfs at La Grange (LGN). This information was used to calculate a preliminary abundance estimate of 37,714 juvenile Chinook salmon at Waterford. Daily Chinook salmon abundance estimates ranged between 0 and 10,660 Chinook (Figure 5). Estimated total abundance by lifestage is 13,399 fry (<50 mm), 4,562 parr (50-69 mm), and 19,213 smolts (≥70 mm). These estimates are preliminary and subject to change.

Total estimated abundance of juvenile Chinook salmon at Waterford during 2009 is an increase over 2008 but lower than during 2007 (Table 3). Differences in juvenile abundance among the three years are reflective of similar differences in adult abundance.

Table 3. Summary of rotary screw trap sampling and juvenile Chinook salmon abundance at Waterford during 2007-2009, and estimated adult Chinook salmon returns to the Tuolumne River during 2006-2008.
 
Waterford sampling table 

One O. mykiss (156 mm) was captured at Waterford during the sampling season. Total O. mykiss catch at Waterford was 8 in 2006, 10 in 2007, and 9 in 2008.
Instantaneous temperature recorded at the trap ranged from 46F to 66F (average: 57F) and turbidity ranged from 0.2 NTU to 321.0 NTU (average: 6.1 NTU). Daily average flow on the Tuolumne River ranged between 148 cfs and 955 cfs (average: 316 cfs) at La Grange (LGN).

Waterford abundance
 
Figure 5. Daily Chinook salmon abundance estimate near Waterford and Tuolumne River flow recorded at La Grange (LGN), 2009.    

The rotary screw trap near Grayson (RM 5) sampled daily from January 8 through June 11. A total of 155 Chinook salmon were captured during the sampling season. Daily catch ranged between zero and 79 Chinook.

No trap efficiency experiments were conducted during the sampling season due to insufficient daily catch. Abundance estimates were calculated using a regression equation developed from trap efficiency data collected during previous years. The preliminary estimate of total juvenile Chinook salmon abundance was 4,420 Chinook, and this estimate consists of 145 fry (<50 mm), 164 parr (50-69 mm), and 4,110 smolts (≥70 mm). Daily Chinook salmon abundance estimates ranged between 0 and 2,253 Chinook (Figure 6). These estimates are preliminary and subject to change.

Total estimated abundance of juvenile Chinook salmon at Grayson during 2009 represents an increase over both the 2007 and 2008 estimates. However, abundance during 2007 may have been underestimated because sampling did not begin until March 23, and fry may have migrated past the site prior to the initiation of sampling (Table 4).

Table 4. Summary of rotary screw trap sampling and juvenile Chinook salmon abundance at Grayson during 2007-2009, and estimated adult Chinook salmon returns to the Tuolumne River during 2006-2008.

Grayson sample table

No O. mykiss were captured at Grayson during the sampling season.

Instantaneous temperature recorded at the trap ranged from 47F to 73F (average: 60F) and turbidity ranged from 0.2 NTU to 256.0 NTU (average: 11.3 NTU). Daily average flow on the Tuolumne River ranged between 180 cfs and 1,308 cfs (average: 417 cfs) at Modesto (MOD).
 
Grayson abundance

Figure 6. Daily Chinook salmon abundance estimate near Grayson and Tuolumne River flow recorded by Modesto (MOD), 2009.

 
Merced River Juvenile Migration 
 
The rotary screw trap at Hatfield State Park (RM 2) sampled from March 30 to May 29. A preliminary estimate of abundance is not yet available.

 
San Joaquin Conditions
 
During the reporting period, flow in the San Joaquin River at Vernalis fluctuated between 498 cfs and 787 cfs (Figure 7). Average daily water temperatures in the San Joaquin River fluctuated during the reporting period, ranging between 73.5 F and 81.0F at Vernalis, between 74.2F and 82.6F at Mossdale; and between 77.7F and 80.3F at Rough 'n Ready Island (Figure 8). Average daily dissolved oxygen (DO) in the San Joaquin River ranged between 5.4 mg/L and 6.1 mg/L in the deep water ship channel (measured at Rough 'n Ready Island) and between 10.6 mg/L and 17.8 mg/L at Mossdale (Figure 9).
 
 
SJR Flow 

Figure 7. San Joaquin River flow at Vernalis, 2008/09.

 

 SJR temperature

 
Figure 8. San Joaquin River daily average water temperature at Vernalis, Mossdale, and Rough 'n Ready, 2008/09.
 

 
 SJR DO

Figure 9. San Joaquin daily average dissolved oxygen at Mossdale and Rough 'n Ready, 2008/09.

 
Delta Exports 
 
Combined (state and federal pumps) total exports fluctuated between 8,197 cfs and 11,440 cfs during the reporting period. Mean daily pumping at the C.W. Jones Pumping Plant (federal pumps previously known as Tracy Pumping Plant) ranged between 3,395 cfs and 4,340 cfs (Figure 10). Mean daily pumping at the Harvey O. Banks Pumping Plant (state pumps) ranged between 4,062 cfs and 7,255 cfs. 
 

Exports


 
Figure 10. Daily exports at the C.W. Jones Pumping Plant (federal) and Harvey O. Banks Pumping Plant (state), 2008/09.

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