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March 12 through
April 15, 2007, Report No.
3
Waterford:
A total of
870 juvenile Chinook salmon were captured between March 12 and
April 15 increasing the season total to 2,301. Daily catch ranged from
one to 95 Chinook (Figure
1). Average forklength was 65.7 mm and ranged from 33 mm to
135 mm. Average weight was 3.9 g and ranged from 0.2 g to
28.8 g.
Zero O.
mykiss were captured during the sampling period.
Figure 1. Chinook
salmon catch at Waterford versus flow at La Grange (LGN).
Five trap efficiency tests were conducted at Waterford
between March 12 and April 8
(Table 1).
Table 1. Release and recapture data for trap efficiency
releases conducted at Waterford.
|
Release Date |
# Released |
# Recaptured |
Trap Efficiency |
Mean at Release (mm) |
Mean at Recapture (mm) |
Flow at LGN (cfs) |
Turbidity (NTU) |
|
3/15/07 |
61 |
4 |
6.6% |
36.0 |
36.3 |
350 |
0.70 |
|
3/29/07 |
48 |
3 |
6.3% |
60.3 |
57.1 |
337 |
0.65 |
|
3/31/07 |
75 |
3 |
4.0% |
47.3 |
58.4 |
337 |
0.43 |
|
4/5/07 |
50 |
2 |
4.0% |
76.0 |
75.0 |
337 |
0.64 |
|
4/11/07 |
63 |
6 |
9.5% |
80.6 |
80.2 |
343 |
1.07 |
Instantaneous water temperature taken at the Waterford trap
ranged between 54°F and 62°F; turbidity ranged from
0.42 NTU to 2.88 NTU; and flows at La Grange ranged
between 297 cfs and 349 cfs.
Grayson:
The
Grayson traps were installed at the same location as previous years
(i.e., RM 5) on March 23 and sampling began immediately.
One Chinook (90 mm; 8.6 g) was captured in the rotary screw traps during this
sample period. Zero O. mykiss were captured during the
sampling period.
Figure 2. Lower
Tuolumne River rotary screw traps at Grayson (RM 5).
Instantaneous
temperature taken at the trap ranged between 58°F and 66°F, and
turbidity ranged from 1.07 NTU to 7.84 NTU. Daily average flow at
Modesto (MOD) fluctuated between 473 cfs and 562 cfs.
The
2006 Tuolumne River Annual Report was recently submitted to the Federal
Energy Regulatory Commission (FERC). To view this document and others
visit
www.tuolumnerivertac.com/documents.htm.
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