| Methods: |
Juvenile Emigration Monitoring:
Fish will be captured using paired 8-foot RSTs. Emigrating fish swim into the rotating drum of the traps and are funneled into a live-well at the tapered end of the drum. Before fish are removed from live-wells, buckets are prepared with fresh water and aeration systems. Live cars will also be prepared if deemed necessary. Once primed for fish work up, a dip net is used to remove fish from the trap's live well and are sorted by race using the Length-at-Date race designation chart. This chart provides date-specific ranges of fork lengths for each Chinook salmon race in the Central Valley.
For each race, if catch is less than or equal to 100, all individuals will be measured, weighed, and assigned a race. If catch is greater than 100, then a random subsample of 75 individuals will be measured, weighed, and assigned a race. This procedure will be used on catch from each live well. Other categories to be considered while sorting and collecting data from trap captured fish will be adipose fin-clipped salmon with CWTs, fish that have been marked for mark-recapture efficiency testing, and non-target fish species. If non-target fish species are captured, they will be enumerated and a random sample of 10 individuals of each species will be measured for total length in millimeters.
In order to reduce stress from handling, fish will be sedated using a solution of MS-222. Carbon dioxide (CO2) will be utilized if the fish can be legally retained by anglers (i.e. steelhead). Fish will be sedated in small batches to reduce the potential of adverse effects due to sedation. Once sedated, measurements to be recorded include fork-lengths (FL) to the nearest mm, wet weights (only salmonids >40mm FL, to the nearest 0.1g), life stage and race. All CCV steelhead and non-adipose fin-clipped Chinook salmon will then be allowed to recover from handling and sedation. Once recovered, fish will be returned to the river. All adipose fin-clipped Chinook salmon are assumed to be implanted with a CWT. Up to 20 Chinook salmon, per day, per race may be euthanized and retained for CWT retrieval and processing. All other fish will be worked up and released as previously described.
Length-at-date criteria are not accurate for all races of Chinook salmon. Thus, tissue samples will be collected from all unmarked Chinook assigned to the winter- and late fall-runs, and 5 samples per day from a random sample of spring- and fall-run salmon. Tissue samples ranging in size from 2-5 mm2 will be collected and place individually inside a uniquely numbered vial containing ethanol; an alternative method of genetic sampling will be to use a small swabs along the fish skin for Chinook that are potentially spring-run Chinook based on length-at-date, when this method is available. Samples will be sent to the Central Valley Tissue Archive for storage and subsequent genetic analysis, if funding is available.
Trap efficiency is evaluated using a mark-recapture technique. When available, the program will use non-ESA listed trap captured juvenile Chinook in trap efficiency trials. Juvenile Chinook will be marked using a biological stain such as Bismarck Brown or Methylene Blue and released in groups of at least 150. Fish may be retained for 48 hours to collect sufficient numbers for appropriately sized release groups. To expand the number of trials conducted during each monitoring year and to have a reliable availably of fish for trap efficiency trials without having to rely on catch numbers at the trapping sites, the program piloted trap efficiency trials using juvenile fall-run and late fall-run from Coleman National Fish Hatchery in 2015. These fish were tagged with a VIE tag and released in groups of 1,000. These techniques proved successful and the program continued these efforts in subsequent sampling seasons.
Hatchery-produced fall-run Chinook salmon will be used to conduct efficiency trials. They may also be used for in-reach survival estimates using acoustic tags. Fall-run Chinook salmon from Coleman National Fish Hatchery will be used for release sites on the Sacramento River, and fall-run Chinook salmon from the Feather River Fish Hatchery will be used for release sites on the Feather River. In the event that hatchery fish are not available, natural-origin fall-run Chinook salmon may be used for efficiency trials and/or acoustic tagging studies.
Central Valley Steelhead Monitoring Program:
The Mainstem Sacramento River Mark-Recapture Program will use wire fyke traps set on the streambed with catch openings facing downstream to capture, tag, sample, and recapture adult steelhead. These traps are simple to construct and require minimal maintenance. More importantly, during previous fyke trapping efforts fish in the traps were found to be in excellent condition when detained for up to 72 hours without substantial occurrence of escape or mortality. Traps will be anchored to the bank with ropes and/or cable maneuvered with winches mounted to watercraft and shore based pick-up trucks. The size of the traps (approximately 20 feet long by 12 feet in diameter) requires they be rolled into the river from the top of a levee, limiting locations at which the traps can be deployed. A DIDSON or device of similar capabilities may be placed at the entrance to the fyke traps to monitor salmonid movements and assist in adjusting trap placement to maximize capture rates.
While steelhead are captured during all hours, the majority are captured at night. Traps will be fished 24 hours a day with all traps being inspected, cleaned, and emptied at least once every 24 hours to minimize the period of time steelhead are detained. Operating personnel will manage time schedules and work duties to assure traps are operating during twilight and evening periods when the potential for maximum capture occurs. Trap holding periods will be reduced if capture rates are greater than expected or result in high fish stress levels. An onsite tagging station (modified pontoon boat retrofitted for fish tagging or something similar) will be used, with experienced staff, to process captured fish and return them to the river with minimal handling. Handling stress will also be reduced through short steelhead transportation times (< 30 minutes), low crowding densities, and onsite tagging. Steelhead (< 5 at a time) will be transferred directly from traps to an aerated holding tank (> 400 liters) on a sampling boat with dip nets for processing. Removal of larger and "trouble-maker" fish will occur first to minimize stress to other fish in the trap. All recaptured steelhead will be released at the site of recapture following recovery from handling. Steelhead unacceptable for marking and transport (e.g., sick, injured) will be released at the capture site immediately upon recovery from handling. All captured steelhead (hatchery and wild) will be enumerated, weighed, measured, sexed (if possible), photographed for body condition, checked for previous tags, and sampled for tissue and scales. Fork lengths will be recorded to the nearest millimeter. The removal of tissue from the upper caudal fin (1 mm hole punch) provides a source for genetic sampling in addition to a secondary mark. Collection of genetic samples from adult steelhead will provide additional samples for current phylogenetic research occurring through NMFS and CDFW single nucleotide polymorphisms (SNP) programs. Scales will be submitted to the CDFW Central Valley Salmonid Tissue Archive for mounting, photographing, ageing, and verification of anadromy. Scale analysis of captured steelhead will provide information on age structure and life history characteristics of wild and hatchery steelhead. A digital photograph of all captured individuals will be recorded for investigation of handling effects at recapture.
Water quality will be monitored continuously during handling to maintain adequate and consistent water temperatures. At least three handling tanks will be used per workstation. Handling tanks will include a primary anesthetizing tank for sedating steelhead, a tagging tank for tagging and biological measurements, and a recovery tank to restore motor function and equilibrium of anesthetized steelhead. Anesthetizing and recovery tanks will be composed of 75 liter round coolers with lids (or something similar) to reduce stress, while individual tagging tanks will be smaller 40 liter tubs with cradles for surgery. Water quality in tanks will be monitored continuously to ensure fish health. Proper water quality is imperative to reducing the negative effects of handling on trapped steelhead; therefore, closed water systems will be used in all handling tanks. Water temperatures in anesthetizing, tagging, and recovery tanks will be within 2° C of ambient water temperature as measured by a thermometer on each trap. Anesthesia of steelhead will not occur at temperatures above 22.5°C. Because high water temperatures significantly reduce the dissolved oxygen carrying capacity of water, dissolved oxygen will be monitored continuously with dissolved oxygen meters and maintained at a minimum of 7-12 ppm (7 mg/L) using compressed oxygen and air stones. Handling and transport times will depend on fyke trap location and number of fish captured but handling from the start of sedation to transport and release will be minimized as much as possible.
All healthy steelhead captured in good condition will be tagged with a PIT tag and externally marked. Half duplex (23 x 3.65 mm or 32 x 3.65 mm) PIT tags will be internally inserted through injection or surgical implantation and detected with electronic transceivers. Hatchery-origin steelhead will receive a two inch, individually numbered, Floy tag inserted with a handheld tagging gun posterior to the dorsal fin. Floy tags will be used to visually identify individuals and determine the PIT tag shedding rate of recaptured individuals. The genetic sample taken from the upper caudal fin with a 1 mm diameter hole punch, can also be used to investigate the retention rate of tagged individuals by establishing a permanent mark. Upon netting from the fyke trap, all steelhead will be scanned with a handheld tag reader, and will be inspected for Floy tags and genetic samples. Tag codes from recaptured fish will be verified with previous tagging lists. Individuals shedding just one of their two unique identification tags (PIT or Floy tag) will be remarked with the appropriate replacement tag. Recaptured individuals that have shed both unique identification tags (identified by caudal hole punch) will be recorded and retagged with PIT and Floy tags. Additionally, a second genetic sample will be taken to confirm the identity of the fish. Effective tagging of steelhead is crucial to calculating escapement while minimizing handling effects. A randomly selected subset of captured steelhead will receive an acoustic tag in addition to PIT and Floy tags to determine migration and survival behavior. Individuals selected for acoustic tagging will be surgically tagged with a VEMCO acoustic transmitter (V13-69kHz or V9-180kHz) or similarly compatible device in the abdomen posterior to the pelvic fins. Only individuals with a tag-to-body weight ratio of 2% will be tagged. Selection methodology of steelhead for tagging will be determined on an annual basis and be dependent on tag and steelhead availability. Acoustic tags will be detected through the network of existing acoustic receivers established by the California Fish Tracking Consortium (http://californiafishtracking.ucdavis.edu/default.shtml). Additional receivers will be installed as needed in tributary streams to confirm the tributary destination of tagged steelhead or in the Sacramento River to track movement at and around trapping locations.
In partnership with other Central Valley monitoring programs, adult winter- and spring-run Chinook salmon, and sDPS green sturgeon that are incidentally captured during fyke trapping activities may be tagged (Floy tags, PIT tags and/or acoustic tags may be applied) and sampled for tissues.
Upper Sacramento River Tributary Steelhead Monitoring:
Adult steelhead immigration monitoring in Sacramento River tributaries will be performed using passive monitoring techniques, including maintaining PIT antennas and operating electronic device counters including video-camera systems, Vaki River-watchers, and DIDSON/ARIS. Where applicable, PIT antennas and electronic device counters will be located within fish ladders. When a fishway is not available or accessible, PIT antennas will be installed instream and temporary resistance-board weirs will be constructed to funnel fish into the electronic device counter’s field of view. Instream resistance-board weirs and fishways will be checked routinely by field staff to make sure that they are free of debris and not obstructing fish passage.
Upper Sacramento River Restoration Site Monitoring:
CDFW Staff will conduct juvenile presence/absence surveys via direct observation and beach-seining at a variety of sites on the Upper Sacramento River, between Keswick Dam (RM 302) and Red Bluff Diversion Dam (RM 243). Most monitoring will be observational, although a limited amount of beach-seining will occur during turbid water conditions which prohibit snorkeling observations. Sampling methods will include snorkel surveys, beach seining, and video surveys. Monitoring will occur prior to restoration activities in order to establish baseline use at proposed restoration sites. Beach seining will be implemented during period of muddy water when snorkeling is ineffective. Additionally, monitoring will occur once restoration activities are complete to determine the success of the restoration project.
Trapping and relocation at Wallace Weir and the CBDC:
CDFW staff will check the Wallace Weir Fish Collection Facility on a daily basis during migration periods of listed species and species of concern (fall and late-fall run Chinook salmon). All fish present will be identified and removed from the fish collection facility. ESA-listed species captured in the facility will be prioritized for collection, processing, transportation, and release back to the Sacramento River following the approved protocol. The Sacramento River release location(s) may vary with species and time of year but will only occur in locations where CDWR or CDFW have property rights or landowner permission to carry out fish releases. When feasible, biological data will be collected for all Chinook salmon, steelhead, and sturgeon captured and relocated (species and or run identification, fork length, sex, physical condition, ad-clip status for salmonids, and tissue samples for genetic analysis). Captured steelhead may receive a PIT tag as part of CDFW's Steelhead Monitoring Program.
When large numbers of Chinook salmon are encountered, biological data will be collected on a systematic subsample of fish (every nth fish sampled). Tissue samples for genetic analysis will be collected, labeled and preserved using standard techniques. Rescued salmonids and sturgeon will be tagged with Floy, PIT, or acoustic tags to provide data on post-rescue survival, movement, and spawning success. In the event that the fish collection facility is inoperable, fish will be collected by beach seine, fyke trap, dip nets, and as a last resort, backpack electro-fishing. Species other than Target Species or Species of Management Concern that are found in the facility will be passed through to the upstream or downstream side of the weir using infrastructure incorporated into the facility.
When fish passage is thought to occur at the Wallace Weir Fish Facility, CDFW will initiate a roving survey using DIDSON imagery at known choke points within the CBDC and associated tributaries to look for focal species. A DIDSON 300 unit with a 60-meter cord will be used for these purposes. The video quality of this unit allows for images of fish and substrate characteristics in turbid water bodies. The unit has a 30-meter viewing range, critical for making observations in many of the choke points in the CBDC where fish may congregate. The DIDSON sonar camera is attached to an aluminum pole and deployed by hand at each monitoring location. DIDSON sonar images will be read in real-time by field staff as images are being acquired and recorded on a field laptop computer. DIDSON image files will be transferred to a dedicated electronic storage file in the CDFW Region II office when staff return from the field. Downloaded videos will be reviewed at the office the same day they were recorded to verify presence or absence of target species at sampling locations. If the presence of target species are observed , field staff will immediately inform project leads who will initiate rescue operations.
Monitoring and Rescues at Fremont, Sacramento, and Tisdale Weirs:
CDFW staff will monitor the CDEC National Weather Service River Forecast Center website during overtopping events to determine when Sacramento River stage height at Fremont, Sacramento, and Tisdale weirs is forecast to drop below the top of the weirs. CDFW staff will then conduct surveys of the weir stilling basins and inundated habitat downstream of the weirs to determine fish species present, estimates of numbers of each species if possible; and potential safety issues regarding fish rescue operations. CDFW staff will use specially designed crowder racks, block nets, dip nets, or hoop nets to capture adult sturgeon and salmonids stranded in the weir splash basins. CDFW staff will use trammel nets to capture adult sturgeon that are stranded in isolated ponds such as the Yolo Bypass Tule and Deep ponds.
Fish species will be enumerated, measured, and evaluated for condition prior to tagging. Fish that appear to be in poor condition will be immediately transported to the Sacramento River for release. Adult sturgeon in fair to good condition will be internally tagged with VEMCO® V16 69 kHz acoustic and PIT tags; and adult salmon in fair to good condition will be externally tagged with Floy tags to provide data on post-rescue survival, movement, and spawning success. Additionally, rescued steelhead may be internally tagged with a PIT tag as part of CDFW's Steelhead Monitoring Program. Juvenile salmon and steelhead will be captured using 1/8-in beach mesh beach seines and placed in aerated five-gallon buckets or coolers, checked for the presence of adipose fins, and measured to determine ESU designation using length-at-date criteria (Green 1992). If large numbers of juvenile salmon are encountered, subsets will be measured to minimize handling stress and numbers of each ESU will be extrapolated from measured fish. Water quality data will be recorded from capture and release locations; and fish will be acclimatized to Sacramento River water temperature if there is more than a two-degree Celsius water temperature difference between capture and release locations.
Upper Sacramento River Redd Dewatering Surveys and Rescue of Stranded Juvenile Salmonids:
This monitoring allows CDFW biologists to predict the flow at which redds will be dewatered on a redd-by-redd basis. Given this knowledge, it is possible to physically modify redds in danger of being dewatered to lessen the impacts to emerging juveniles. During the study, each observed redd is classified from a list of five dewatering descriptors ranging from "not dewatered" to "totally dry". For the purposes of this study, a dewatered redd is identified as any active redd that has its highest section (the tailspill mound) exposed to the air. This would indicate that the river flow has decreased from the time when the redd was constructed and adverse impacts to egg or juvenile survival are present.
A small number of dewatered redds may be excavated to document the level of mortality resulting from dewatering eggs and/or juveniles. Winter-run Chinook salmon redds in shallow water will be identified and monitored by boat crews to determine formation date and subsequent emergence date of each redd. These redds will be repeatedly measured to determine the depth of water column above the highest point of the redd during each river flow reduction. When a redd is in jeopardy of becoming dewatered, (based on the redd depth and the schedule of flow reductions), CDFW may act if deemed necessary to reduce the impacts of dewatering. One or two days prior to a Keswick Reservoir flow reduction, a field crew will gently remove substrate from the tops of redds that are likely to become dewatered (e.g., redds in water 2-3 inches or less before a 250 cfs reduction) to a depth sufficient to allow water to continue flowing over the redd top after flow reductions. Water depth, velocity, and temperature will be measured at the redd before and after the substrate removal process. Photographs will document the substrate removal process. Numbers of fry observed during the redd removal will be noted. Crews will revisit redds and repeat this protocol if necessary until after the calculated emergence date of each redd has passed.
Monitoring for juvenile salmonid stranding is typically conducted immediately after flow reductions from Keswick Reservoir either by boat from the main river channel or on foot from the bank. Efforts to locate and monitor stranding sites are typically conducted from the Tehama Bridge (RM 229) to Keswick Dam (RM 302). Isolated and partially or potentially isolated pools are observed and marked on a handheld GPS. All stranding sites observed are also photographed (example found in the attached document - Jarrett and Killam 2014). Environmental conditions including water depth, temperature, dissolved oxygen, and available cover are also recorded at each stranding site. Prior to conducting rescue efforts, CDFW staff will enumerate and identify salmonids to species by visual observation, including underwater observation and underwater photography. Juvenile Chinook salmon are further classified by run based by estimating fork lengths and comparing them to length-at-date criteria (Green 1992). CDFW will then determine if rescue efforts are necessary based on the likelihood of juvenile survival at each stranding location and will be based on current and expected environmental conditions. Prioritization of rescue efforts are based on numbers of listed salmonids present at each stranding site accessibility, potential for hydrological reconnection of the stranding site to the main channel, and short-term survival prognosis.
If fish rescue is deemed necessary, CDFW staff will conduct rescue efforts using appropriately sized beach seines, dip nets, electrofishing, or a combination thereof. Methods used to capture stranded salmonids are based on staff experience and feasibility of methods at each location. Multiple passes will be made with beach seines dip nets or backpack electrofishing units. Captured fish will be transferred to buckets of water for identification enumeration, and fork length measurement. Reconnection of stranding sites to the main channel using hand tools or motorized equipment (e.g., backhoe) may be considered in lieu of fish capture and relocation. The feasibility of reconnecting a stranding site is based on the substrate of the stranding site and the proximity to the Sacramento River main channel or hydrologically connected aquatic habitat. Both permanent and temporary re-connection techniques are considered during assessment.
Documented stranding sites are regularly revisited as resources allow throughout the survey season. The status of each stranding site is evaluated to determine if and when the location reconnects to or disconnects from the main river system. Fish present are counted and identified to assess mortality of stranded juveniles over time. Similar methodology will be used to rescue and relocate listed salmonids within Upper Sacramento River Basin tributaries. If conditions are not suitable for release within the body of water where fish have been rescued (such as lack of water, poor water quality, high water temperature, low dissolved oxygen, etc.), a one-ton flat-bed truck fitted with a 200-gallon oxygenated water tank will be used to transport rescued salmonids for release at the Sycamore Boat Launch downstream from the Red Bluff Diversion Dam (RM 243) or the nearest suitable release location on the Upper Sacramento River. |
Resources Needed to Accomplish Objectives: |
Juvenile Emigration Monitoring:
Personnel: 4 full time field crews with 16 staff members.
Equipment: 2 Pontoon boats, 5 - 16-foot boats, 6 vehicles, 14 - 8-foot rotary screw traps, sampling gear, tags.
Steelhead Monitoring:
Personnel: one full time field crew with 5 staff members.
Equipment: boat for fish work-up with holding tanks, vehicles, fyke traps, trailer for traps, DIDSON Cameras, sampling gear, tags (PIT, Floy, acoustic), PIT tag readers, acoustic receivers
Restoration Site Monitoring:
Personnel: one full time field crew.
Equipment: boat, DIDSON camera, snorkel gear.
Rescues, Relocation, and Redd Dewatering Surveys:
Personnel: 3 – 5 staff members for the trapping and tagging of salmon, steelhead and sturgeon.
Equipment: 2 vehicles, 2 fish transport tanks/trailers. Beach seines, backpack electrofishing units, large dip nets, acoustic tags, Floy tags, and PIT tags. A DIDSON unit and laptop will be used and is powered by a Honda 2000 generator. CDFW seasonal personnel will conduct the trapping under the direction of an Environmental Scientist. |