Week of February 27, 2023

Updated Catch Numbers

To date, we had cap­tured over 372 fish via trap net and sein­ing. Based on size chart assess­ments, these includ­ed 69 wild fall-run sized, 1 late-full-run-sized, 8 win­ter-run-sized, and 7 spring-run-sized Chi­nook salmon. We still had found/experienced 0 mor­tal­i­ty of any non-fall-run wild Chi­nook salmon.   Over­all mor­tal­i­ty has been low.  About 3.5% (13/372) mor­tal­i­ty of all fish encoun­tered so far with fyke and seine. All of these were dead when we encoun­tered them, no fish have died dur­ing or short­ly after our han­dling that we have seen. Of these, 5 were PIT-tagged hatch­ery fall-run salmon, 4 wild fall run salmon, 1 shad, 2 mos­qui­to fish, 1 sun­fish.

General In-field Activity Updates

As a result of col­lab­o­ra­tion between the Cal­i­for­nia Rice Com­mis­sion, UC Davis, Nat­ur­al Resources Con­ser­va­tion Ser­vice, Nation­al Marine Fish­eries Ser­vice (NMFS) and CA Depart­ment of Fish and Wildlife (CDFW) dur­ing our Field Day on Feb­ru­ary 23, 2023, it was decid­ed that we would not begin drainage of the project field on March 1, as per the draft man­age­ment prac­tice pro­to­col.  Rea­son being that our JSATS (teleme­try) fish were not yet at tag­gable size due to the unsea­son­ably cold weath­er.  If we drained the UC Davis Team would have had to relo­cate these fish else­where caus­ing chal­leng­ing logis­ti­cal issues and stress on the fish.  There­fore, NMFS and CDFW sug­gest­ed we con­sid­er an exten­sion of the flood­ing time­line and all par­ties agreed to keep the project going deep­er into March to allow JSATS fish growth.  We real­ly appre­ci­at­ed the col­lab­o­ra­tion and sup­port for this approach which should serve to max­i­mize the qual­i­ty of the data being col­lect­ed from this project.  Many thanks to the grow­er, Steve Nead­er, for being will­ing to keep his field flood­ed for a longer peri­od of time to let every­thing play out.  Of course, tem­per­a­ture and dis­solved oxy­gen (DO) will be con­tin­u­ous­ly mon­i­tored dur­ing this peri­od to be pro­tec­tive of the fish.

The field team replaced the fyke net at the drain with a larg­er mesh fyke.  This is because the fish com­ing in are larg­er at the begin­ning of the field sea­son and the larg­er mesh will enable bet­ter water flow-through when the field is drained.  They also did some extra work to rese­cure all the JSATS fish cages to with­stand the windy con­di­tions a bit bet­ter.  Solar pan­els at the PIT sta­tions were increased in size to per­form bet­ter with the cloudy con­di­tions.  Data from the HOBO log­gers and PIT sta­tions was down­loaded.  Tem­per­a­ture and DO con­tin­ued to be well with­in healthy para­me­ters.  They also mea­sured JSATS fish at both the project field and our sec­ond set of JSATS fish on the dry­side field.  Reminder:  The dry side fish are pri­mar­i­ly just an “insur­ance pol­i­cy” in the event that some­thing goes wrong with the main project field.

General Lab Activity Updates

The UC Davis Team was very busy in the lab clip­ping adi­pose fins on about 8,500 lab-reared fish.

Web-related Resources

All the recent PIT tag data was uploaded to the In-field Salmon Move­ment Shiny App.  We’ve also made some inter­pre­tive upgrades to the App to make it a bit eas­i­er for every­one to inter­pret.  A link to this App is now promi­nent­ly linked to the Project Web­site.  Basi­cal­ly, this App enables a user to click on any one of over 3,100 PIT-tagged fish that has been detect­ed in the field thus far and view all of the areas of the field that the fish have trav­elled to since ini­tial detec­tion. 

UC Davis field crew getting ready to check the fyke with mud everywhere. They do this work every day regardless of conditions.
UC Davis field crew get­ting ready to check the fyke with mud every­where. They do this work every day regard­less of con­di­tions.
Another one of the daily fyke checks to gather and measure fish.
Anoth­er one of the dai­ly fyke checks to gath­er and mea­sure fish.
Video of the UC Davis field crew col­lect­ing a fish from the fyke net.
Minnow collected from the fyke net being measured. All fish, including non-salmon species, are all recorded in the count as part of studying the total fish community that is in the project field.
Min­now col­lect­ed from the fyke net being mea­sured. All fish, includ­ing non-salmon species, are all record­ed in the count as part of study­ing the total fish com­mu­ni­ty that is in the project field.
Rice grower’s dog, Opie, waiting patiently for him to return to the truck and let him run around in the mud.
Rice grower’s dog, Opie, wait­ing patient­ly for him to return to the truck and let him run around in the mud.
UC Davis lab facility showing the tanks that hold our lab-reared salmon and the mobile tank that is used to transport the salmon to the project field.
UC Davis lab facil­i­ty show­ing the tanks that hold our lab-reared salmon and the mobile tank that is used to trans­port the salmon to the project field.
Picture of Alexandra Wampler of the UC Davis Team gathering salmon to take them into the lab for fin clipping.
Pic­ture of Alexan­dra Wampler of the UC Davis Team gath­er­ing salmon to take them into the lab for fin clip­ping.
Video of Alexan­dra Wampler gath­er­ing salmon for fin clip­ping.
Close-up picture of our lab-reared fall run salmon.
Close-up pic­ture of our lab-reared fall run salmon.
Video of our lab-reared salmon in an aer­at­ed ice chest.
Alex Wampler explains the role of adi­pose fin clip­ping of our lab-reared salmon.

Other Field News

Update on the 2022–23 Salmon Project Fieldwork Season

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team unloading salmon release equipment from truck trailer at the river

Week of March 13, 2023

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Salmon surgery at UC Davis to install tags into farmed fish, Tuesday, March 7, 2023. (Photo Brian Baer)

Week of March 6, 2023

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