| Volume 2, Issue 12 |
April 24, 2008 | |
Upcoming Events
Apr. 24-25: Delta Vision Blue Ribbon Task Force Meeting
May 28: CALFED Ops Meeting June 12: TRTAC |
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Key Highlights
VAMP Update. The VAMP period will begin April 22 and end on May 22, with a target flow of 3,200 cfs at Vernalis (VNS) and combined exports of 1,500 cfs. The Head of Old River Barrier will not be installed this year during the VAMP period due to concerns of potential impacts to Delta smelt.
2007/08 Juvenile Migration Monitoring. Juvenile migration monitoring continues on the San Joaquin tributaries. Daily catches remain relatively low.
San Joaquin River Conditions. San Joaquin Basin water temperatures and dissolved oxygen fluctuated during the reporting period but exhibited an overall increasing trend.
Delta Exports. Combined total exports (state and federal pumps) fluctuated throughout the reporting period and ranged between 1,327 cfs (April 12) and 4,654 cfs (April 4).
Interesting News. "A place to play on the Delta?; Lawmaker's plan would transform stretch into a state recreation area"
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.
If you have any questions regarding this newsletter, please contact Doug Demko at 530-342-9262 or by e-mail at dougdemko@fishbio.com. | |
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VAMP Update
The Vernalis Adaptive Management Plan (VAMP) period will begin on April 22 and end on May 22, with a target flow of 3,200 cfs at Vernalis (VNS) and combined exports of 1,500 cfs. The Head of Old River Barrier (HORB), the only measure clearly demonstrated to improve the survival of San Joaquin fall-run Chinook salmon smolts, will not be installed this year due to concerns of potential impacts to Delta smelt. An acoustic-tagging salmon study will be conducted beginning the last week of April. In preparation for this study, acoustic tagging training was recently completed at Mokelumne River Hatchery between April 14 and April 23.
A total of approximately 1,000 juvenile Chinook salmon will be tagged at Merced River Hatchery in four groups (April 28, April 30, May 5, and May 7) for release on subsequent days. Tagged fish are scheduled for four separate releases: two at Durham Ferry on April 29 and May 6, and two at Stockton on May 1 and May 8. Stationary receivers are deployed at several locations in the San Joaquin River and Delta between the Head of Old River split and Mallard Island to track the migration route selection and survival of tagged smolts (see map below).
Map of primary (red) and secondary (yellow) priority acoustic monitoring sites, with number of independent arrays in parentheses. Source: 2008 VAMP study plan.
To view the 2007 VAMP technical report, click here. |
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2007/08 Migration Monitoring
The Calaveras River rotary screw trap at Shelton Road (RM 29) sampled 15 out of 28 days between March 17 and April 13.
A total of 266 O. mykiss (Table 1) were captured during the reporting period, increasing the season total to 776. Daily catch ranged between zero and 68 O. mykiss. A total of 252 young-of-year (YOY; ≤100 mm) and 14 Age 1+ (101-299 mm) O. mykiss were captured. Average forklengths and weights of O. mykiss are provided in Table 1. Most of the O. mykiss captured were rated as fry (n=238). There were also some parr (n=17), silvery parr (n=9), and smolts (n=2).
Table 1. Biosampling data for O. mykiss captured and measured at Shelton Road between March 17 and April 13, 2008. Parentheses indicate range. 
Instantaneous temperatures taken at the trap ranged from 49ºF to 56ºF, and turbidity ranged from 0.1 NTU to 1.4 NTU. Daily average flow fluctuated between 28 cfs and 203 cfs at New Hogan Dam (NHG), between 0 cfs and 1 cfs flows at Cosgrove (COS), and between 0 cfs and 61 cfs at Bellota (MRS).
The Stanislaus River rotary screw trap at Oakdale (RM 40) sampled continuously between March 17 and April 13.
A total of 745 juvenile Chinook salmon were captured during the reporting period, increasing the season total to 19,346. Daily catch ranged between one and 176 Chinook. Average forklengths and weights of Chinook salmon are provided in Table 2 for 602 fish that were measured. Most measured Chinook were smolts (n=404), including four larger fish (i.e., > 100 mm), but there were also some parr (n= 112) and fry (n= 90).
No O. mykiss were captured during this reporting period.
Table 2. Biosampling data for Chinook salmon captured and measured at Oakdale between March 17 and April 13, 2008. Parentheses indicate range. Note: four measured fish excluded from the parr/smolt averages.
Instantaneous temperature taken at the trap ranged from 47ºF to 57ºF, and turbidity ranged from 0.3 NTU to 1.9 NTU. Daily average flow fluctuated between 1,001 cfs and 1,519 cfs at Goodwin Dam (GDW) and fluctuated between 741 cfs and 1,299 cfs at Orange Blossom Bridge (OBB).
One trap efficiency release was conducted on April 10. A total of 86 marked Chinook were released, none of which were recovered (Table 3).
Table 3. Trap efficiency tests conducted at Oakdale between March 17 and April 13, 2008.
The Stanislaus River rotary screw traps at Caswell (RM 8) sampled 24 out of 18 days between March 17 and April 13.
A total of 23 juvenile Chinook salmon were captured during the reporting period increasing the season total to 52.
No O. mykiss were captured during the reporting period.
Instantaneous temperature taken at the trap ranged from 52ºF to 58ºF, and turbidity ranged from 1.2 NTU to 5.1 NTU. Daily average flow ranged between 340 cfs and 1,438 cfs at Ripon (RIP).
Daily catch was insufficient to conduct trap efficiency tests during this reporting period.
The Tuolumne River rotary screw trap at Waterford (RM 30) sampled continuously between March 17 and April 13.
A total of 359 juvenile Chinook salmon were captured during the reporting period, increasing the season total to 2,600. Daily catch ranged between one and 30 Chinook. Average forklengths and weights of Chinook salmon are provided in Table 4 for 355 fish that were measured. Over half of the Chinook measured were rated as smolts (n= 279), including two larger fish (i.e., > 100 mm). There were also some parr (n= 32) and fry (n= 46).
No O. mykiss were captured during the reporting period.
Table 4. Biosampling data for Chinook salmon and O. mykiss captured and measured at Waterford between March 17 and April 13, 2008. Parentheses indicate range. Note: two measured fish excluded from parr/smolt averages.
Instantaneous temperature taken at the trap ranged from 54ºF to 67ºF, and turbidity ranged from 0.6 NTU to 4.7 NTU. Daily average flow ranged between 158 cfs and 180 cfs at La Grange (LGN).
Daily catch was insufficient to conduct trap efficiency tests during this reporting period.
The Tuolumne River rotary screw traps at Grayson (RM 5) sampled continuously between March 17 and April 13.
A total of seven juvenile Chinook salmon were captured during the reporting period, increasing the season total to 138. Daily catch ranged between zero and two Chinook. Average forklengths and weights of Chinook salmon are provided in Table 5. All salmon captured were smolts.
One O. mykiss smolt (pictured left; 224 mm FL; 102.3 g) was captured on March 31, increasing the season total to two. This is the first year that more than one O. mykiss has been captured during a sampling season at Grayson.
Table 5. Biosampling data for Chinook salmon and O. mykiss captured at Grayson between March 17 and April 13, 2008. Parentheses indicate range.
Instantaneous temperature taken at the trap ranged from 55ºF to 68ºF, and turbidity ranged from 1.4 NTU to 7.3 NTU. Daily average flow fluctuated between 252 cfs and 327 cfs at Modesto (MOD).
Daily catch was insufficient to conduct trap efficiency tests during this reporting period.
The 2008 TID seining study survey number six was conducted on April 1 at various locations on the Tuolumne and San Joaquin Rivers.
A total of 16 Chinook salmon were captured in the Tuolumne River at various locations at or upstream of, Charles Road (RM 24.9), and none were captured at the San Joaquin seine sites. The number of Chinook captured in the Tuolumne decreased by about 60% compared to the last three surveys. On the other hand, Chinook size continued to increase with forklengths ranging between 42 and 84 mm (avg: 57.8 mm). Fry (≤50 mm FL) were most abundant (n=7) followed by parr (n=5) and smolts (n=4).
No O. mykiss were caught in either river.
During the surveys, flows were about 170 cfs in the Tuolumne River at La Grange (LGN) and were about 2,400 cfs in the San Joaquin River at Vernalis (VNS).
The Merced Riverrotary screw traps at Hatfield (RM 2) sampled 21 out of 28 days between March 17 and April 13.
A total of three juvenile Chinook were captured; one each March 21, 22, and 24. Average forklength was 87 mm (range: 79-92 mm); no data regarding weights provided. All were rated as smolts.
No O. mykiss were captured during this reporting period.
Instantaneous temperature taken at the trap ranged from 58ºF to 63ºF, and turbidity ranged from 2.2 NTU to 7.7 NTU. Daily average flow at Cressy (CRS) ranged between 217 cfs and 281 cfs.
Two trap efficiency tests were conducted at Hatfield on March 17 and April 1 using hatchery raised juvenile Chinook salmon with resulting efficiencies of 3.7% and 9.3%, respectively.
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San Joaquin River Conditions
During the reporting period, flow in the San Joaquin River fluctuated between 1,820 cfs and 2,499 cfs (avg: 2,167 cfs) at Vernalis. Water temperature in the San Joaquin exhibited an overall increasing trend with fluctuations between 55.9 °F and 64.8 °F (avg: 59.4 °F) at Vernalis; between 56.9 °F and 67.8 °F (avg: 61.0 °F) at Mossdale; and between 58.9 °F and 64.3 °F (avg: 60.6 °F) at Rough 'n Ready Island. Dissolved oxygen (DO) in the San Joaquin River also exhibited an overall increasing trend with fluctuations between 8.8 mg/L and 12.6 mg/L (avg: 11.2 mg/L) at Mossdale and between 6.6 mg/L and 11.2 mg/L (avg: 9.3 mg/L) in the deep water ship channel (measured at Rough 'n Ready Island).
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Delta Exports
Mean daily pumping at the C.W. Jones Pumping Plant (federal pumps previously known as Tracy Pumping Plant) fluctuated throughout the reporting period ranging between 839 cfs and 2,617 cfs. Mean daily pumping at the Harvey O. Banks Pumping Plant (state pumps) fluctuated throughout the reporting period and ranged between 488 cfs and 2,819 cfs. Combined total exports (state and federal pumps) fluctuated throughout the reporting period and ranged between 1,327 cfs (April 12) and 4,654 cfs (April 4).
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Interesting News
"A place to play on the Delta?; Lawmaker's plan would transform stretch into a state recreation area. A stretch of the Delta due west of Thornton could become California's newest haven for hunters, anglers, boaters and hikers if legislation sponsored by Assemblywoman Lois Wolk becomes law.
Wolk's idea is for the state to buy Prospect Island and Little Holland Tract from the federal government, and Liberty Island from the Trust for Public Land, and turn them into a state recreation area. This would allow a variety of uses, including hunting, bird-watching and fishing." Full story at: http://www.recordnet.com/apps/pbcs.dll/article?AID=/20080321/A_NEWS/803210333/-1/A_NEWS | |
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