May 7 through May 20, 2007

The Stanislaus River Weir continued to operate well during this sampling period with flows averaging near 1,500 cfs at the weir site.  Daily weir monitoring operations remained consistent as compared to previous updates.  Flows from Goodwin Dam were scheduled to start dropping yesterday, however, the reduction has been postponed until further notice. 

Two Chinook salmon passed through the weir between May 7^th and May 20^th. Other fish species recorded by the Vaki RiverWatcher during this sampling period include 209 Sacramento suckers, 159 hardhead, 60 Sacramento pikeminnow, 34 striped bass, 25 common carp, 4 black bass, 4 American shad, and 3 catfish (Figure 1). 

Figure 1.  Left: A Sacramento pikeminnow (Ptychocheilus grandis), Sacramento sucker (Catostomus occidentalis), and a hardhead (Mylopharodon conocephalus); and Right: An American shad (Alosa sapidissima).

Two Chinook salmon were recorded by the RiverWatcher during this sampling period.  One passed at 3:07am on May 9^th and the other at 6:28am on May 15^th.  Both fish were female; the second was ad-clipped (Figure 2 + 3). 

Five carcasses were recovered on top of the weir during the sampling period including two striped bass, one Sacramento sucker, one goldfish, and one aquarium store "Oscar" (Figure 4).  One of the striped bass had a treble hook still in its mouth and the other had a hook scar indicating that they may have died from angling stress.  All of the carcasses were processed and were then passed downstream of the weir.

Environmental conditions at the weir site varied slightly during the sampling period. Flow at Orange Blossom Bridge (OBB) ranged from 1,190 cfs to 1,203 cfs while flow at Ripon (RIP) ranged from 1,405 cfs to 1,444 cfs. Goodwin Dam (GDW) outflows ranged between 1,498 cfs and 1,508 cfs (data source: CDEC). Turbidity at the weir ranged between 0.97 NTU and 1.97 NTU; and dissolved oxygen (DO) ranged between 10.10 mg/L and 11.01 mg/L. At Rough 'n Ready Island (RRI) in the San Joaquin River's Deep Water Ship Channel, DO ranged between 9.31 mg/L to 11.51 mg/L. Daily instantaneous water temperature at the Stanislaus River Weir ranged between 55.2ºF to 57.1ºF.

If you had trouble viewing this email update in the intended format you can find all of the weir email updates at Cramer Fish Sciences - Stanislaus River Weir e-postcard web page.

If you would like to be added or removed from this email distribution list please send an email to Jesse Anderson.

The Stanislaus River Weir Project is funded by the U.S. Fish and Wildlife Service Anadromous Fish Restoration Program and is supported by the USBR, CDFG, and other local agencies and interests.

To view other summaries click on the links below:

Previous

Next