Aloha Area Acipenser Associates,

Between Monday (3/28) at 10:30 AM and today (4/1) at 9:40 AM PST, the realtime network of 69 kHz acoustic detectors heard eight Green and thirteen White Sturgeon. Four of the Green Sturgeon and all of the White Sturgeon are of previously detected fish.

Among the Green Sturgeon this week, I'm glad to report that there was a successful rescue of a stranded fish at Fremont Weir on Tuesday (3/29). This previously non-tagged adult male Green Sturgeon was tagged and released, upon which time it continued upstream, being detected by the real time detectors at Knights Landing on Wednesday (3/30). Another [female White*] Sturgeon was rescued and tagged yesterday (3/31), but has not yet been detected by any of the real time detectors yet.

The other seven detected Green Sturgeon, three detected for the first time in 2016, were also heard moving upstream this week. The three new Green Sturgeon were heard first at the CCF bridge (3/29, 3/30 & 3/30) followed by the Tower Bridge within a day. The first such fish to enter has also been detected Thursday (3/31) at Knights Landing. As to previously detected Green Sturgeon, the one detected 3/28 at Tower Bridge has now (3/30) moved up to Knights Landing. Both the Green Sturgeon that were at Knights Landing (3/28) and Tisdale (3/26) have been detected by our furthest upstream real-time detector at Colusa (3/31 & 3/27 respectively).

Of the thirteen White Sturgeon, only two were detected at Lisbon Weir, which numerically is a large departure from previous reports. In fact, one White Sturgeon last detected at Lisbon Weir (3/13) has entered the mainstem of the Sacramento River and has been detected at the CCF and Tower Bridges (3/30). Three last reported at the Sacramento Bridges (3/24, 3/27 and 3/27) have made their way up to Knights Landing (3/28, 3/29 and 3/31 respectively), whereas another one (3/27) appears to be headed back downstream, detected by both bridges again on 3/31. Two other White Sturgeon were seen going upstream this week, both transiting from Knights Landing (3/23 and 3/25) to Tisdale Weir (both 3/29). Two others were heard in the same location as their last reported location (2/14..3/29 at Colusa, 3/27..3/29 at Tidale). The last two remaining White Sturgeon were heard moving downstream, one detected 2/25 at Colusa was heard 3/29 at Tisdale and 3/31 at Knights Landing and the other was at at Tisdale on 3/28 and was down to Knights Landing by 3/29.

Text and images of previous 2016 reports are now online [here] . The tabular output has been made available from the early 2016 reports, but I need to do some minor tidying on the most recent 3 or so. The long-promised White Sturgeon visualizations aren't QUITE ready, but will be soon.

--Matt