Research at the Sacramento River Delta Cross Channel Beginning in 2000, multi-disciplinary, multi-agency research projects were initiated at the Delta Cross Channel in the northern portion of California's Sacramento-San Joaquin River Delta. A portion of the research pertains to the effects of the DCC and localized water currents on migratory behavior of juvenile chinook salmon. Unlike most riverine water diversions, movements of water at the DCC are more complex because of tidal influence. The following animated graphics display examples of some of the research results obtained during November 2000. Additional research was also performed in the fall of 2001.

radiotag.avi: This avi displays movements of individual radio-tagged juvenile chinook salmon (colored squares) released one mile upstream of the DCC and the relative magnitude and direction of water velocity vectors in the vicinity of the DCC. Note that the earliest arriving chinook pass the DCC during an ebb tide and as the tide changes to flood conditions, later arriving salmon move into the DCC. Additionally, a fish that had previously passed the DCC is moved back upstream by the flood tide and into the DCC.

trawlrel1.avi: This avi integrates water velocity data (colored vectors), drifter data (colored squares), and the trawl recovery data for the Sacramento River (top time series) and the DCC (bottom time series), for the period immediately following the first paired release (Nov 13). Note that the arrival of the drifters to the DCC, which approximates the arrival of the fish, occurs during a strong ebb condition on the Sacramento River, and all drifters move past the DCC. Fish are collected at this time in the Sacramento River trawl, but are not seen in the DCC trawl until 3+ hours later, when flow vectors begin to indicate positive flow into the DCC.

trawlrel2.avi: This avi integrates water velocity data (colored vectors), drifter data (colored squares), and the trawl recovery data for the Sacramento River (top time series) and the DCC (bottom time series), for the period immediately following the second paired release (Nov 14). Note that as the drifters move downstream, there is a flood condition on the Sacramento River, and the flow vectors show a positive flow into the DCC. Prior to the drifters arrival at the DCC junction, conditions quickly shift, and the ebb tide begins, and flow into the DCC stops. All drifters move past the DCC. Fish are seen shortly afterward in the Sacramento River trawl (purple bars), but are not seen in the DCC trawl. Later, after positive flow begins into the DCC, fog forces the suspension of trawling, resulting in a period during which no trawl data was collected (underscored on each time series).

trawlrel3.avi: This avi integrates water velocity data (colored vectors), drifter data (colored squares), and the trawl recovery data for the Sacramento River (top time series) and the DCC (bottom time series), for the period immediately following the third paired release (Nov 20). Note that the arrival of the drifters to the DCC, which approximates the arrival of the fish seen in the Sacramento River trawl, occurs late on the ebb tide on the Sacramento River. Very shortly after, flow vectors begin to appear in the DCC, about simultaneously with the first fish collected in the DCC trawl.

trawlrel4.avi: This avi integrates water velocity data (colored vectors), drifter data (colored squares), and the trawl recovery data for the Sacramento River (top time series) and the DCC (bottom time series), for the period immediately following the fourth paired release (Nov 21). Note that the arrival of the drifters to the DCC, which approximates the arrival of the fish (yellow bars), occurs during a strong ebb condition on the Sacramento River, and all drifters move past the DCC. Fish are collected at this time in the Sacramento River trawl, but are not seen in the DCC trawl until 3+ hours later, when flow vectors begin to indicate positive flow into the DCC. This is very similar to the results depicted in trawlrel1.

flowfield.avi: This avi presents 24 hours of velocity data collected in the junction of the Delta Cross Channel that shows the flow in the delta cross channel can change dramatically over the tidal cycle. For example, during the ebb tide on the Sacramento River, there is little (or no) flow into the cross channel. During flood tides, however, the currents flow into the cross channel from the Sacramento River from both upstream and downstream of the cross channel.

acoustic.avi: This avi file shows movement and distribution of salmon smolts from the release site downstream to the Delta Cross Channel measured as changing densities of hydroacoustic targets recorded during continuous surveys of the river channel following release.Yellow 'X' marks location of simultaneously released drogue. Note that most targets remain just behind the drogue.


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