Week of January 30, 2023

The bypass flood­wa­ters reced­ed enough to enable the project field to be safe­ly accessed and the inten­sive data col­lec­tion and man­age­ment prac­tice imple­men­ta­tion offi­cial­ly began.  UCD sci­ence team work includ­ed sein­ing, begin­ning phas­es of PIT sys­tem instal­la­tion in the field, and instal­la­tion of a large fyke net sys­tem at the out­fall drain of the field so that most fish can start to be count­ed upon exist­ing the field.  At this ini­tial stage of fyke net oper­a­tion, the small­est-sized fish were unable to be held in the fyke net for count­ing. The grow­er began to man­age the spe­cial hole/notch boards as the boards have become acces­si­ble with the water lev­els con­tin­u­ing to recede.  These are spe­cial­ized flow con­trol boards in the rice field rice box­es that allow for the fish to pass from one check to anoth­er and then ulti­mate­ly out of the field entire­ly.  The rea­son these boards aren’t acces­si­ble all at once is because the fields are mild­ly “ter­raced” and so the fields clos­est to the drain side are the last to get down to the tar­get depth of 10–12 inch­es. 

The sci­ence team began count­ing and releas­ing fish dai­ly, as per our State and Fed­er­al agree­ment allow.  By the end of this week just over 40 salmon and sev­er­al oth­er fish species had be iden­ti­fied and record­ed.  Based on salmon size-class, it appears we have count­ed most­ly fall run (32).  How­ev­er, all four runs were record­ed as using the field to this point, includ­ing 1 late-Fall run, 8 Win­ter run and 2 Spring run, dur­ing sein­ing and fyke net oper­a­tions.  We also record­ed split­tail, shad, hard­head min­now, sil­ver­side and hatch­ery steel­head using the project field.  Occa­sion­al preda­tors species were also seen includ­ing bass and sun­fish.  PIT tag­ging also con­tin­ued this week.  To this point, the UCD Team had PIT-tagged about 2000 lab-reared salmon in advance of lat­er release into the project field.  About 200 of these have also been JSATS-tagged.

Just one of sev­en planned rice box­es wired with a PIT-tag read­er sys­tem to mon­i­tor fish move­ments.
The fyke net sys­tem placed just below the field drain to tem­porar­i­ly detain fish for dai­ly count­ing, record­ing and release.
The UCD Team check­ing the fyke net for fish.
The UCD Team con­duct­ing sein­ing oper­a­tions in the project field.
Exam­ple of rice box with notched top board (for fish pas­sage) wired to read fish with a PIT tag as they pass though.
The grow­er plac­ing a “hole board” into the rice box to enable fish pas­sage between checks.
Mod­i­fied boards in a rice box allow­ing for fish pas­sage through a notched board.
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