California Hatchery Review Project. Appendix VIII. Feather River Hatchery Spring Chinook Program Report

Transcription

1 California Hatchery Review Project Appendix VIII Feather River Hatchery Spring Chinook Program Report June 2012

2 Introductory Statement from the California HSRG This program report was developed by contractor staff tasked with providing background information to the California HSRG on hatchery programs, natural population status and fisheries goals in California. The resulting report is one of many sources of information used by the California HSRG in their review process. Information provided in this program report was developed through interviews with hatchery staff, regional, state and tribal biologists working in the basins and a review and summarization of the pertinent scientific literature. The draft program report was then provided to interview participants for review and comment on multiple occasions. Comments received were incorporated into the report and the report finalized. Because of the review process, it is believed the report represents an accurate snapshot in time of hatchery operations, natural salmon population status and fisheries goals in California as of This program report may or may not be consistent with the consensus positions of the California HSRG expressed in the main report, as their primary involvement was in the preparation of Section 4.3, Programmatic Strategies, which compares existing program practices to the statewide Standards and Guidelines developed by the California HSRG.

3 Table of Contents 1 Description of Current Hatchery Program Programmatic Components Operational Components Facilities Broodstock Spawning Incubation Rearing Release Fish Health Populations Affected by the Hatchery Program Current Conditions of Affected Natural Populations Feather River Spring and Fall Chinook Populations Long term Goals for Natural Populations Fisheries Affected by the Hatchery Program Current Status of Fisheries Long-term Goals for Affected Fisheries Programmatic and Operational Strategies to Address Issues Affecting Achievement of Goals Issues Affecting Achievement of Goals Natural Production Issues Ecological Interaction Issues Operational Issues Programmatic Strategies Broodstock Program Size and Release Strategies Incubation, Rearing and Fish Health Monitoring and Evaluation Direct Effects of Hatchery Operations on Local Habitats, Aquatic or Terrestrial Organisms Literature Cited...36 List of Figures Figure 1. Estimated total recoveries per 1 million juveniles released (summed over recovery years ) for brood years in different recovery areas for in-river and bay releases Figure 2. Feather River Spring Chinook- percent of total survival in various fisheries: brood years Feather River Hatchery Spring Chinook Program / June 2012 Page i

4 List of Tables Table 1. Numbers of ad clipped and non-ad clipped Chinook carcasses recovered and CWT rates of naturally spawned Chinook in two sections of the Feather River, Table 2. Populations in the Central Valley fall and late-fall Chinook ESU, ordered from north to south (unlisted ESU) Table 3. Populations in the Central Valley spring Chinook ESU, ordered from north to south (ESA listed threatened) Table 4. Chinook salmon escapement in the Feather River basin ( )...15 Table 5. Total percent survival (catch plus escapement) and exploitation rates for FRH Table 6. spring Chinook brood years Total percent survival of spring Chinook reared at FRH by release location (catch plus escapement) Table 7. Broodstock Source Table 8. Broodstock Collection Table 9. Broodstock Composition Table 10. Mating Protocols Table 11. Program Size Table 12. Release Strategy Table 13. Fish Health Policy Table 14. Hatchery Monitoring by Fish Health Specialists Table 15. Facility Requirements Table 16. Fish Health Management Plans Table 17. Water Quality Table 18. Best Management Practices Table 19. Hatchery and Genetic Management Plans Table 20. Hatchery Evaluation Programs Table 21. Hatchery Coordination Teams Table 22. In-Hatchery Monitoring and Record Keeping Table 23. Marking and Tagging Programs Table 24. Post-Release Emigration Monitoring Table 25. Adult Monitoring Programs Table 26. Evaluation Programs Table 27. Direct Effects of Hatchery Operations Appendices Appendix A-1 Hatchery Program Review Questions Appendix A-2 Feather Spring Chinook Program Data Tables Appendix A-3 Hatchery Program Review Analysis Benefit-Risk Statements Appendix B Natural Populations Potentially Affected by the Hatchery Program Page ii Feather River Hatchery Spring Chinook Program / June 2012

5 Red Bluff Diversion Dam Black Butte Dam Thomes Creek XW Stony Creek Sacramento River Mi State Hwy 99 Thermalito Annex Rearing Facility (CDFG) Deer Creek # Chico Butte Creek Gridley Boat Ramp Live Oak Big Chico Creek State Hwy 99 ") ") XW XW Feather River Honcut Creek Feather River Fish Hatchery (CDFG) Oroville Dam Feather River Hatchery Dam Boyds Pump uba River I - 80 Bear River Putah Diversion Dam Vallejo # I - 5 Putah Creek XW I - 80 Mare Shipyard Sacramento River Sacramento River Wickland Oil Storage Site Sacramento # Coon Creek Dry Creek Auburn Ravine XW # # ") XW American River Lodi Stockton Cosumnes River ") XW Nimbus Fish Hatchery (CDFG) Nimbus Dam Mokelumne River Fish Hatchery (CDFG) Woodbridge Dam Calaveras River Mokelumne River Camanche Dam US Hwy 50 Stanislaus River Feather River Hatchery Spring Chinook Program # Cities Lakes and Other Waterbodies Rivers Roads ") Hatcheries Juvenile Release Sites Adult Collection Sites XW Dams San Joaquin River # Modesto t 1 in = 20 miles Miles Tuolumne River Turlock Merced River Croc Merce C:\04GISData\ProjectData\CaliHSRG\MapProjects\CentralValley2\ProgramByProgram\FeatherSpChinook.mxd Published Date : 12/8/2011

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7 1 Description of Current Hatchery Program In 1960, California voters authorized the Department of Water Resources (DWR) to construct and operate the State Water Project. Oroville Dam and reservoir on the Feather River were essential project components providing water storage, hydroelectric power, flood control, and recreational benefits. The dam is located five miles east of the City of Oroville. The Feather River Hatchery (FRH) is a component of the Oroville Project that was constructed in the mid-1960s downstream of Oroville Dam and about 66 miles upstream from the confluence of the Feather and Sacramento rivers. An additional facility, the FRH Annex, is located downstream adjacent to the Thermalito Afterbay near Interstate 99. The California Department of Fish and Game (CDFG) operates and maintains FRH under contract with the DWR. Although there are no other agencies, tribes, or cooperators directly involved in operating FRH, one advisory group provides guidance. The Feather River Technical Team advises FRH personnel to help integrate the hatchery operations into management of the salmonid fisheries below Oroville Dam. 1.1 Programmatic Components The FRH was constructed to mitigate for Chinook salmon and steelhead spawning habitat blocked by Oroville Dam. The spring Chinook program has two purposes: (1) an integrated harvest program that mitigates for lost habitat and juvenile fish production from the Feather River; and (2) an integrated conservation program to aid in the recovery and conservation of spring Chinook salmon from Deer, Mill and Butte creeks. Hatchery produced spring Chinook are intended to spawn naturally or to be genetically integrated with the targeted natural population as FRH broodstock. There are no specific goals for the number of adult spring Chinook salmon produced by this program; however, the juvenile production goal is to release 2 million spring Chinook salmon smolts sized at 60 fish per pound (fpp). Hatchery and natural-origin Feather River spring Chinook salmon were listed as threatened as part of the Central Valley spring Chinook Evolutionarily Significant Unit (ESU) under the federal Endangered Species Act in The FRH also propagates fall Chinook salmon and Central Valley steelhead (O. mykiss), the latter listed as a threatened species. 1.2 Operational Components Facilities The main Feather River Hatchery consists of an office and maintenance building, fish ladder, gathering tank, spawning building, main hatchery building, four holding and twelve juvenile rearing ponds (ten raceways and two rearing channels), ultraviolet water treatment building, and hatchery buildings. Water from eight of the ten rearing raceways, the rearing channel, and the hatchery buildings is collected in a main sump and pumped directly into two settling basins. All upstream migrating fish are stopped at the Fish Barrier Dam at Feather River Mile (RM) 66, about 0.5 miles below Thermalito Diversion Dam (RM 66.5) and immediately upstream of the FRH. The 91-foot-high concrete Fish Barrier Dam releases water to maintain fish habitat in the reach downstream to the Thermalito Afterbay Outlet. Feather River Hatchery Spring Chinook Program / June 2012 Page 1

8 The Fish Barrier Dam diverts fish into a 1/3-mile-long gated fish ladder that leads to the FRH. The ladder gates are generally open from about September 15 through the following June to ensure that spring- and fall-run Chinook salmon and steelhead have an opportunity to enter the hatchery. The fish ladder consists of a series of steps and pools. Pool length ranges from 8 to 1,000 feet, with a minimum width of 6 feet and a minimum water depth of 2 feet. Flow velocities range from 2 to 5 feet per second (fps); the maximum drop between pools is 1 foot. An enlarged section of the fish ladder at its upstream terminus functions as a gathering tank, entrapping fish ascending the ladder. A mechanical sweep (crowder) gathers the fish and deposits them into the abutting spawning building. Four concrete circular tanks hold the fish until they are ready to spawn. A secondary hatchery facility, the FRH Annex, is located at RM 55 and includes an office, maintenance building, and four rearing raceways. An on-site well supplies about 12 cubic feet per second (cfs) to this facility. Water is supplied to FRH from Lake Oroville and is diverted by gravity flow into an aeration tower downstream at the Thermalito Diversion Dam. From the aeration tower, water is distributed to the hatchery buildings and fish rearing areas. Up to 110 cfs can be diverted to the hatchery, although only 74 cfs is used at full operation. Currently, more water is diverted to the aeration tower than is used at the hatchery in order to maintain sufficient water pressure. When the minimum discharge through the hatchery is less than 74 cfs, the surplus water is released directly into the Feather River through an overflow pipe at the aeration tower. Between 40 and 74 cfs of flow-through wastewater discharges to two settling basins (approximately 300 feet long, 30 feet wide, and 15 feet deep) located near an embankment on the Feather River. The two settling basins are constructed with overflow pipes that are capable of discharging directly to the Feather River; however, no direct discharges have occurred from these ponds since their completion in Water from eight of the ten rearing raceways, the rearing channel, and the hatchery buildings is collected in a main sump and pumped directly into two settling basins. Wastewater from the two newer raceways is discharged directly to one of the settling basins. If the main sump pumps are overwhelmed or fail, this wastewater can be discharge to the Feather River via the sump overflow pipe. Wastewater from the holding tanks adjacent to the main hatchery building also discharges directly to the sump overflow pipe. The FRH also has several raw water discharge points - the aerator overflow pipe, the fish ladder and gathering tank, the four holding tanks adjacent to the main hatchery building, and a fish return pipe in the spawning room of the main hatchery building. When the fish ladder is in use during broodstock and spawning periods, water from the fish ladder, a gathering tank, and four holding tanks is discharged directly to the Feather River. These direct discharges contain minimal quantities of fecal material, but no chemicals or unconsumed fish food is present since fish are not fed or treated in these locations Broodstock Adult spring Chinook salmon that ascend the fish ladder from the Feather River are used for broodstock. Based on historical number of eggs per female and survival rates, approximately 750 pairs of spring Chinook salmon are required to meet the annual 3 million egg take goal and 2 million smolt release goal. Page 2 Feather River Hatchery Spring Chinook Program / June 2012

9 The FRH fish ladder is opened in May and June to collect phenotypic spring run Chinook salmon for broodstock. Each fish trapped is tagged with two sequentially numbered colored external Hallprint dart tags placed under the dorsal fin (or other tag deemed appropriate by DWR and CDFG). The same color tag is used for each trapping period. The number of recaptured fish and tag numbers for any mortality are recorded. A tissue sample is collected and preserved from each fish that is trapped and tagged. All tagged spring-run Chinook are immediately released back to the Feather River in the vicinity of the FRH. Poor water quality, the inability to chemically treat adults (due to discharge limitations), and the lack of adequate adult holding facilities requires that spring Chinook be allowed to mature in the Feather River rather than in the hatchery. Approximately 30% of tagged fish that were returned to the river during the spring Chinook trapping period are often unaccounted for by carcass surveys in the fall, angler reports, and hatchery returns. The fish ladder remains open until June 30, after which a barrier is installed to prevent entry of additional fish. Fish holding in the ladder are allowed about 2 weeks to complete the ascent. Those that do not move up into the hatchery are crowded back into the river and released, or crowded up to the spawning building for processing. At that time, the ladder is dewatered and cleaned. The fish ladder is reopened on about September 15 to allow fish to enter the hatchery for sorting and artificial spawning. Consistent with hatchery physical constraints and water quality, all returning fish are allowed free access to the hatchery after that date. In the event conditions develop that create a potential for unacceptable fish loss, free access may be temporarily curtailed. All tagged spring-run Chinook salmon trapped at the FRH after September 15 may be used for broodstock. Sexually mature fish are spawned, while unripe fish are retained in the adult holding ponds. All adult Chinook salmon in excess of those needed for artificial spawning are euthanized and processed as described below. No live adult Chinook salmon are currently transported to or from FRH. Only fish trapped and tagged during the spring broodstock collection period are selected as spring-run Chinook salmon broodstock, unless additional fish are needed to meet broodstock goals. As not all spring Chinook entering the Feather River return to the hatchery when the ladder is open, spring Chinook identified at the time of spawning by coded-wire tag (CWT), otolith mark, or genetic tag may also be used as broodstock Spawning Females and males that are sexually mature and demonstrate free flowing eggs or sperm are selected for spawning. Mating is accomplished using one female and one male, although one male may fertilize multiple females when the number of males is insufficient. Grilse do not comprise more than 2% of the male fish spawned unless needed when numbers of male fish are insufficient. All eggs taken and fertilized on a single day are identified as an egg lot and assigned a lot number. The hatchery goal is to collect 3 million green eggs. Spring Chinook salmon identified as broodstock from fish trapped or transferred from a holding tank are anesthetized using CO 2 gas. No effort is made to select for specific characteristics or traits. If necessary to help meet spring Chinook production targets, dry spawning and on-site CWT reading or genetic tag reading techniques may be used to identify additional spring Chinook for broodstock. Only fish with CWT, genetic tag, or thermal mark indicating FRH spring-run are used as broodstock in this event. Supplemental untagged broodstock identified by CWT are Feather River Hatchery Spring Chinook Program / June 2012 Page 3

10 collected in the following manner: non-hallprint tagged and adipose fin-marked (indicating CWT) are grouped into a round tank from the time the ladder opens until roughly October 7th. No new CWT fish are selected after October 7th. This group of fish is mated following real-time CWT reading protocols until all fish have been processed. Once the eggs have been fertilized, they are immersed in an iodine solution to help eliminate pathogens. This is effective against a broad spectrum of disease-causing microorganisms, and is used to kill on contact a wide variety of bacteria, viruses, fungi, protozoa, and yeasts. All Chinook salmon carcasses and eggs collected by FRH personnel are processed in one of two ways. Carcasses suitable for human consumption are provided in approximately equal proportions to the California Emergency Food Link which contracts with a fish processing company, or to Oroville-area Native American tribes. Carcasses and eggs not suitable for human consumption are disposed of through contract with a processing/rendering company Incubation Spring Chinook eggs are incubated in vertical egg incubators. Individual families are not kept separate during incubation. Fresh water is circulated through incubation trays at water temperatures averaging 55 Fahrenheit (F) (±4 F). Iodine is flushed through incubators on a daily basis to reduce disease and egg mortality. After about 30 days, the iodine treatment is stopped. Based on information from FRH annual reports, survival to hatching averages 72%, but has been as high as 85% in recent years. Surplus eggs are not intentionally taken; however, egg lots or proportions of egg lots subsequently determined not needed may be eliminated. Excess eggs identified by a Hallprint tag are culled in reverse chronological order (latest to earliest) in order to increase separation between spring and fall Chinook spawn timing. Those taken from parents identified by real time CWT reading (or other non-hallprint tag fish) are culled in reverse chronological order (latest to earliest). These eggs are culled in equal proportion to those of the Hallprint tag group. All spring Chinook salmon culled eggs are disposed of through a rendering company Rearing Spring Chinook fry are transferred from incubators into raceways where they remain until ready for release. The survival rate for green eggs to the eyed egg stage since 2003 has averaged 80% (range 66 to 91%). From 1999 to 2008, the survival rate for eyed egg to fry transferred to the rearing ponds averaged 71% (range 52 to 89%) and from ponded fry to released smolts has averaged 84% (range 48 to 100%). Information on length or condition factor is not routinely collected. Raceways are approximately 600 feet by 10 feet with an average depth of 2 feet and can accommodate flows up to 4 cfs. At maximum area and flow, each raceway can hold about 1 million Chinook salmon at a size of 60 fpp. Once fry begin free swimming and feeding, the flow is increased and as the fish increase in size, additional pond space is provided at the discretion of the hatchery manager. Juvenile spring Chinook salmon growth varies but juvenile fish typically reach a size of 60 to 90 fpp by April. At the time of release, the rearing loading has a flow index (FI) of 2.6 and a density index (DI) of Fish density is adjusted to reduce disease and pathogen issues, and to ensure adequate growth. Page 4 Feather River Hatchery Spring Chinook Program / June 2012

11 Once the Chinook salmon fry are ready to feed, they are placed on a semi-moist food for the remainder of the 6-month rearing period. Fry are fed up to 12 times per day. Juvenile fish in the raceways are fed using a blower mounted feeder that is driven past the raceway. The amount of food fed through the rearing period depends on body weight and appetite, that is, they are given as much as they will eat without wasting food. Food conversion rates are not calculated Release The program goal is to release up to 2 million spring-run Chinook salmon smolts annually at a minimum size of 60 fpp. In the past, all or proportions of the production have been released in San Francisco and San Pablo bays. The present strategy is to release all FRH spring Chinook juveniles in the Feather River. Release sites include Boyd s Pump Launch Ramp (RM 22), or south of uba City near the intersection of Oswald Road and the Garden Highway. Alternative locations may be used for small experimental groups to study the effects of release location on survival. Since operations began, over 51 million juvenile spring Chinook have been released. During the past ten years, FRH released 21,078,159 spring Chinook smolts. Juvenile Chinook salmon are released as soon as possible after reaching an average size of 60 fpp. Depending on water temperatures and growth rates, fish are typically released during April or May. Fish are transported to the release sites using fish transport tank trucks. The transport tank is filled with fresh water from the hatchery water supply and if necessary, the transport tank water may be chilled to cool the transport water to 47 to 53 F. Ice is not used to cool the water. Fish transport tank trucks are typically loaded at no more than one pound of fish per gallon of water. No salt is added to the water. Transportation time from the hatchery to the release site is typically less than one hour and fish are released directly into the receiving water. Since 2002, DWR personnel have attempted to mark (using CWTs and adipose fin-clipping) 100% of spring Chinook smolts produced and released, a goal that is not always achieved. Otolith thermal marking efforts were initiated at FRH to help differentiate hatchery-and naturalorigin Chinook. Since 2005, 100% of FRH spring Chinook salmon have been differentially marked through manipulation of rearing water temperatures. Juvenile spring-run Chinook produced by FRH in excess of production numbers are not released into anadromous waters. If approved by the CDFG Fisheries Branch Chief, the FERC Ecological Committee (established through the Oroville Facilities Settlement Agreement) and related fishery regulators, surplus fish may be stocked into non-anadromous waters Fish Health Fish health is monitored by the CDFG Fish Health Laboratory during times of increased fish mortality. Diagnostic procedures for pathogen detection follow American Fisheries Society professional standards as described in Thoesen (1994). Appropriate treatments are recommended or prescribed by a CDFG fish pathologist/veterinarian as appropriate, and follow-up examinations are performed as needed. Health inspection data for infectious hematopoietic necrosis virus (IHNV) and the bacteria Renibacterium salmoninarum is collected from ovarian fluid of returning adult females annually during artificial spawning. Feather River Hatchery Spring Chinook Program / June 2012 Page 5

12 2 Populations Affected by the Hatchery Program This section presents information about natural populations that could be affected to some extent by the FRH spring-run Chinook salmon program. Appendix B contains descriptions of the other populations potentially affected by this program. Portions of the sections that follow apply equally to both Feather River Chinook runs; hence they are considered together, where appropriate. It bears noting that spring- and fall-run Chinook in the Feather River are sometimes not distinguished as being separate races due to their close resemblance genetically and behaviorally, in which case they are simply called fall Chinook (USDI 2010). Both runs are overlapped spatially and temporally on the natural spawning grounds. The spring-run is sometimes referred to as nominal spring Chinook because it is likely that the existing early-timed run in the Feather River is actually an admixture of the fall-run and the historic spring-run (Brown et al. 2004; Garza et al. 2008). The discussion that follows distinguishes the two populations where it is needed for the purpose of this report. It should be recognized that the FRH supports the only spring Chinook hatchery program currently in the Central Valley. None of the Central Valley spring Chinook populations that are still considered to be pure spring-run are hatchery propagated. The potential effects of the Central Valley Chinook hatchery programs, including the FRH Chinook programs, on natural salmon populations in the Central Valley have been reviewed by a number of authors in recent years. The following summarizes the major programmatic issues identified in these reviews, with emphasis on the FRH spring-run Chinook program where relevant information is available. In their review of the factors associated with the recent collapse of the Sacramento fall Chinook salmon, Lindley et al. (2009) concluded that anthropogenic effects, including hatchery production, likely played a significant role in increasing the susceptibility of this run to collapse during the recent period of unfavorable ocean conditions. They hypothesize that the historical loss and simplification of habitat in combination with the increasing dominance of hatchery fish have substantially reduced the life history diversity that once buffered the stock from the effects of environmental variation. These factors may explain the lack of significant genetic variation among Central Valley fall Chinook stocks, which is atypical for a basin of this size (Garza et al. 2008; Banks et al. 2000; Williamson and May 2005). Lindley et al. (2009) suggested two plausible explanations. One is that Central Valley fall Chinook never had significant geographical structuring because of frequent migration among populations in response to highly variable hydrological conditions. The other is that extensive straying and interbreeding of hatchery fish has genetically homogenized the ESU. Historic losses and degradation of habitat as a result of mining, dams, altered hydrology, levee construction, agricultural conversion, and other land uses may have also contributed to the loss of genetic diversity (Moyle et al. 2010; oshiyama et al. 1998, 2001; Williams 2006; Lindley et al. 2009). Concerns regarding the effects of hatchery fish on natural populations focus largely on the loss of genetic diversity and fitness of naturally spawning fish. For Central Valley fall and spring Chinook hatchery stocks, the practice of releasing large numbers of juveniles into the bay or delta region and associated high straying rates is a major concern (CDFG and NMFS 2001). Transporting hatchery fish downstream to either the Sacramento-San Joaquin Delta or west of there to the bay has gone on for many years to improve survival and contribute to fisheries. Survival has generally been enhanced significantly by releasing fish either downstream of the Page 6 Feather River Hatchery Spring Chinook Program / June 2012

13 delta or within the delta (CDFG and NMFS 2001; Lindley et al. 2009; personal communications, Alice Low, CDFG, April 2011). Garza et al. (2008) stated that the lack of genetic structure of fall-run Central Valley Chinook is likely at least partly due to these practices and the consequent migration pattern (straying) upon return, thereby increasing gene flow between stocks. Annual releases of hatchery fall and spring Chinook generally exceed 30 million, and over half of these fish are released at locations downstream from their natal hatchery (mostly in San Francisco and San Pablo bays). The Joint Hatchery Review Committee examined the level of straying of hatchery fish in the Central Valley and found that off-site releases result in straying indices as high as 90%, with higher indices as the distance from release point to hatchery increases (CDFG and NMFS 2001). On-site releases typically resulted in stray indices of 5 to 10%. This general pattern was also evident from a recent analysis of CWT recovery data associated with different hatcheries and release locations (ICF Jones & Stokes 2010). These patterns of juvenile releases occur for Feather River hatchery Chinook, but it is uncertain whether stray rates are as high as those observed for some other Central Valley hatchery programs. Most or all of the fall Chinook produced at the FRH have been trucked for release into the bay for many years, a protocol that continues today. Beginning in 2002, FRH altered its release strategy so that half of the spring Chinook were released into the bay, with the other half being released into Feather River (Cavallo et al. 2009) a protocol that also continues today. Early analysis of CWT recoveries of FRH Chinook shows greater straying by bay-released fish, but not as high as seen at some facilities. For example, cohort analysis for 1998 brood year FRH fall and spring Chinook concluded that about 90% of the adults produced by bay releases that survived back to the Sacramento system returned to the Feather River (including the FRH) and about 10% strayed outside the Feather River basin. By comparison, about 6% of the in-basin releases strayed to streams other than the Feather River (Palmer-Zwahlen, et al as cited in Brown et al. 2004). Brown et al. (2004) noted, however, that it is quite likely that the 1998 cohort analysis significantly underestimated the straying rate, mainly due to a lack of consistent tag recovery efforts on the major Chinook salmon spawning streams. A more recent analysis comparing in-basin Feather River releases to bay releases of spring-run Chinook suggests higher stray rates than those reported earlier (DWR 2011). This analysis is based on returns for brood years 2004 through It should be noted that the target marking/tagging percentage of the releases in those years was 100%. Preliminary results for CWT recoveries through 2009 (expressed as the number recovered per 1 million tags released) are illustrated in Figure 1 (four brood years combined). The total recovery rate was 31% greater for bay-released fish than in-river releases for fisheries, hatchery, and in-basin spawning grounds combined, presumably reflecting improved survival. In contrast, the recovery rate of fish that strayed to spawning areas outside the Feather River was over 12 times greater for bay-released fish than for in-basin released fish, indicating much higher stray rates. The majority of the bayreleased strays were found in the Sacramento River (68.4%), followed by uba River (14.8%), and American River (13.5%). Incomplete recoveries in 2010 (not incorporated into Figure 1) also demonstrated a much higher stray rate for bay releases than for in-river releases. No in-river released fish were recovered out-of-basin in 2010 (not all data have been reported for all streams), while over 600 bay releases were recovered in Battle Creek (both upstream and downstream of the hatchery weir), Clear Creek (upstream of weir) and the Sacramento River. Particularly alarming was that DWR (2011) estimated that 24% of the spring Chinook spawning escapement upstream of the Coleman hatchery weir in Battle Creek was comprised of Feather River springrun strays. Feather River Hatchery Spring Chinook Program / June 2012 Page 7

14 # Recovered/Million Released In River Release Bay Release Commercial Hatchery Spawning Ground Sport Strayed Fish Source: DWR 2011 Figure 1. Estimated total recoveries per 1 million juveniles released (summed over recovery years ) for brood years in different recovery areas for in-river and bay releases. In general, hatchery fall Chinook that spawn in the wild appear to be a large and increasing fraction of the spawning escapement in the Central Valley (Barnett-Johnson et al. 2007), but evaluation of the contributions of natural-origin fish to naturally spawning populations has been limited by the lack of an adequate marking and recovery program. Otoliths of salmon captured in the California coastal fishery in 2005 indicated that natural-origin fish comprised only 10% (plus or minus 6%) of the catch (Barnett Johnson et al. 2007). Assuming roughly equivalent survival of hatchery- and natural-origin fish from the fishery to the spawning grounds, these results imply that currently about 90% of the return could consist of hatchery fish. However, this study was based on a small sample size in a single year of harvest, so results may not be representative of hatchery composition in all years. As a component of current federal and state monitoring and evaluation programs, a constant fractional marking program has recently been implemented for fall Chinook to improve the estimation of hatchery contributions to ocean and inland harvest, inriver spawning escapement, and hatchery returns (personal communication, Alice Low, CDFG, April 2011). As noted above, the target for marking FRH spring-run Chinook is 100%. Preliminary estimates of the composition of the naturally spawning Chinook in Feather River for 2010 are reported in Hartwigsen (2011). The year 2010 was the first year when all of the fall-run hatchery fish in Feather River would have been represented by marking under the constant fractional marking program, except for 5-year-old fish, which are relatively few. Spring-run hatchery fish have been marked at a 100% rate for a period of years. The results suggest that essentially 100% of the Chinook spawning in the low flow channel (see Table 1 for location) were hatchery-origin fish (this would include both spring-run and fall-run fish). In the high flow channel, located downstream, the results suggest that upwards of 60% of the naturally spawning Chinook were hatchery-origin fish. Nearly all natural spawning by Feather River Chinook occurs in these two river sections. These estimates are made by simply expanding the number of adipose fin-clipped fish observed by a factor of four, since the constant fractional marking program involves ad-clipping every fourth fish released. These preliminary results seem to suggest that Page 8 Feather River Hatchery Spring Chinook Program / June 2012

15 fry produced by naturally spawning Chinook in Feather River do not survive well to adulthood, since estimates of natural fry in the low flow channel alone are often between 2.5 to 10 million fish (Bilski and Kindopp 2009). The disparity between the spawning composition and fry production estimates warrants closer attention, which cannot be provided here. Sampling for marks and tags on the natural spawning grounds in Feather River in the past several years shows a low percentage of strays from outside this river. Hartwigsen (2010, 2011) estimated that in both 2009 and 2010, 98.7% of the tagged fish that spawned in either the river or in the hatchery were comprised of Feather River-origin fish. Table 1. Numbers of ad clipped and non-ad clipped Chinook carcasses recovered and CWT rates of naturally spawned Chinook in two sections of the Feather River, River Section Location River Miles Low Flow Channel High Flow Channel Thermalito Afterbay Outlet to Fish Barrier Dam Gridley Bridge to Thermalito Afterbay Outlet RM 59 - RM 68 RM 51 - RM 59 Number Clipped Number Nonclipped CWT Rate 1,413 1, % % Combined 1,438 1, % Source: Hartwigsen 2011 The effects of large numbers of hatchery-origin Chinook spawning naturally in the Feather River appear to be clearly evident in genetic analyses reported by Banks et al. (2000), Williamson and May (2005), and Garza et al. (2008). All of these studies showed pervasive population homogeneity for fall Chinook throughout the Central Valley. These results, as well as others pertinent to the Feather River spring-run, are particularly relevant to this report the observations and views of Garza et al. (2008) are summarized below: The widespread homogeneity within the fall populations indicates substantial recent gene flow between all sampled fall-run populations throughout the Central Valley. Concordant with previous studies, the nominal spring run in the Feather River is genetically fall-run, despite exhibiting a difference in run timing compared to the fall run. The genetic characteristics of the spring-run samples support the hypothesis that this run, while nearly indistinguishable genetically from fall fish, is a remnant of the ancestral Feather River springrun population that migrated upstream of the dam that now blocks upstream passage, but that has been heavily introgressed with fall-run genes. 1 The homogeneity of the fall runs in the Central Valley is likely at least partly due to the prevalent practice of trucking and releasing fish into the bay and delta, as noted earlier in this section. In contrast to the genetic characteristics of the Feather River spring-run, the data show that the three primary naturally spawning spring Chinook populations in the Sacramento system 1 It should be noted that the spring run population spawns in the river relatively close to the hatchery, probably within the upper mile of the low flow channel. Fall run Chinook also spawn in this area. Thus, the runs are overlapped both spatially and temporally. Feather River Hatchery Spring Chinook Program / June 2012 Page 9

16 not supported by hatchery propagation (Butte Creek and Deer/Mill creeks) are genetically distinct and monophyletic (meaning that they all arose from a common spring-run ancestor). This finding shows that strays from the Feather River have not affected the genetic characteristics of these runs. It bears noting here that it remains unclear how the spring and fall runs in the Feather River maintain differences in run timing while they are essentially genetically indistinguishable with genetic microsatellite data. There appears to be very significant overlap in when the runs spawn and where they spawn naturally in the river (e.g., Hartwigsen 2011). O Malley et al. (2007), while confirming that the runs were indistinguishable using neutral microsatellites, reported genetic differentiation at candidate loci linked to migration timing (so-called Clock gene), which they suggested mediates migration traits in the Feather River. Hence, there is evidence that the Feather River runs are able to maintain some differentiation despite pressures against it. This fact is important for conservation purposes; therefore the DWR plans to install a separation weir in the upper part of the low flow channel to help ensure genetic separation. The spring run would be allowed upstream of the weir while the fall run would not, based presumably on some characteristics of run timing. A note made by Garza et al. (2008) regarding the potential for conserving the Feather River spring-run genetic material is relevant here: it may be possible to preserve some additional component of the ancestral Central Valley spring-run genomic variation through careful management of this stock (Feather River spring-run) that can contribute to the recovery of the ESA-listed Central Valley spring-run ESU, although it will not be possible to reconstitute a pure spring-run stock from these fish. Ecological interactions between hatchery and naturally produced fish have also been identified as a concern regarding potential effects of hatchery programs, and such interactions may be magnified by straying and the limited capacity and diversity of habitats currently available to natural Central Valley stocks. Competition is probably most significant in streams with hatcheries (Battle Creek and the Feather, American, Mokelumne, and Merced rivers) where relatively large numbers of hatchery-origin fish may compete with naturally produced fish for spawning or rearing habitat (CDFG and NMFS 2001). The potential outcome of these interactions could be reduced survival and productivity of natural stocks. The current practice of releasing most hatchery fall Chinook smolts in the estuary avoids potential competition or predation between hatchery and naturally produced juveniles in upstream rearing areas. The tradeoff with this strategy is the potential for greater adverse interactions in the estuary and possibly coastal marine areas. Field observations in the Sacramento River indicate that hatchery Chinook salmon released as smolts do not compete with naturally produced juveniles for freshwater rearing habitat because of their strong migratory behavior (Weber and Fausch 2003). Although these hatchery releases substantially increase the densities of smolts migrating through the estuary, the potential for competition (for estuarine food resources) may be low because of relatively rapid migration rates and limited dependence on the estuary for rearing (MacFarlane and Norton 2002). However, concerns remain regarding the potential density dependent effects of hatchery releases on the survival and growth of naturally produced juveniles during their first year at sea, especially in years of low marine productivity (Williams 2006). Page 10 Feather River Hatchery Spring Chinook Program / June 2012

17 2.1 Current Conditions of Affected Natural Populations Four seasonal runs of Chinook salmon occur in the Sacramento-San Joaquin River system, and each can potentially be affected by the FRH Chinook programs. Each run is defined by a combination of adult migration timing, spawning period, and juvenile residency and smolt migration periods. The runs are named after the season of adult upstream migration: winter, spring, fall and late-fall. The fall and late-fall runs spawn soon after entering the natal streams, while the spring and winter runs typically remain in their streams for up to several months before spawning. Formerly, the runs also could be differentiated to various degrees on the basis of their typical spawning habitats: spring-fed headwaters for the winter run, higher-elevation streams for the spring run, mainstem rivers for the late-fall run, and lower-elevation rivers and tributaries for the fall run (oshiyama et al. 2001). The Central Valley fall/late-fall run Chinook salmon ESU was classified as a federal Species of Concern on April 15, 2004 due to specific risk factors. The ESU includes all naturally spawned populations of fall run Chinook salmon in the Sacramento and San Joaquin River basins and their tributaries, east of Carquinez Strait. The Central Valley spring run Chinook salmon ESU was listed as a threatened species on September 16, 1999; threatened status was reaffirmed on June 28, The ESU includes all naturally spawned populations of spring run Chinook salmon in the Sacramento River and its tributaries in California, including the Feather River, as well as the Feather River Hatchery spring Chinook program. The Sacramento River winter Chinook salmon ESU was listed as endangered on January 4, 1994; endangered status was reaffirmed on June 28, The ESU includes all naturally spawned populations of winter run Chinook salmon in the Sacramento River and its tributaries in California, as well as two artificial propagation programs: winter-run Chinook from the Livingston Stone National Fish Hatchery (NFH), and winter Chinook in a captive broodstock program maintained at Livingston Stone NFH and the University of California Bodega Marine Laboratory. The fall run is currently the most abundant Chinook run in the Central Valley, and was probably the most abundant run historically, as well (Moyle 2002; Williams 2006). Moyle (2002) observed that the fall run life history strategy makes it ideal for hatchery production, almost to the exclusion of other runs. Historically, the other seasonal runs were also large (oshiyama et al. 2001), testifying to the tremendous diversity of habitats and life histories that supported the pre-disturbance Central Valley Chinook populations (Lindley e al. 2009). The spring run is considered to have been the dominant run in the San Joaquin system, where the natural flow regime would have favored these fish (Moyle 2002; Fisher 1994 cited in Lindley et al. 2009). Over the decades, the spring runs dwindled in the Sacramento system so that they now consist of few remnant populations; the San Joaquin spring runs are extinct (Lindley et al. 2004). The extensive system of dams in the Central Valley affected these runs much more than the fall run because the dams blocked much access to cold water habitats (Lindley et al. 2009). Under existing conditions, fall Chinook are raised at five major Central Valley hatcheries (Coleman NFH, Feather River, Nimbus, Mokelumne River, and Merced) which together release more than 32 million smolts each year. As a result, they are currently the most abundant of the Central Valley races, contributing to large commercial and recreational fisheries in the ocean and popular sport fisheries in the freshwater streams. Feather River Hatchery Spring Chinook Program / June 2012 Page 11

18 While the fall run is the most abundant run in the Central Valley, the aggregate population has declined during the last several years from an average of 450,000 ( ), to less than 200,000 fish in 2006 and to about 90,000 spawners in The population includes both natural- and hatchery origin fish, but the proportion of hatchery fish can be as high as 90% depending on location, year, and surveyor bias (Barnett Johnson et al. 2007, as cited in Moyle et al. 2008). Central Valley fall-run Chinook migrate upstream as adults from July through December and spawn from early October through late December. Run timing varies from stream to stream. Late fall-run Chinook migrate into the rivers from mid-october through December and spawn from January through mid-april. In general, San Joaquin River populations tend to mature earlier and spawn later in the year than Sacramento River populations. These differences could have been phenotypic responses to the generally warmer temperature and lower flow conditions found in the San Joaquin River Basin relative to the Sacramento River Basin. The majority of young salmon of these races migrate to the ocean during the first few months following emergence, although some may remain in freshwater and migrate as yearlings. Adult Central Valley spring Chinook salmon leave the ocean to begin their upstream migration in late January and early February (CDFG 1998, as cited in NMFS 2009), and enter the Sacramento River between March and September, primarily in May and June (oshiyama et al. 1998). Spring Chinook salmon generally enter rivers as sexually immature fish and must hold in freshwater for up to several months before spawning (Moyle 2002). While maturing, adults hold in deep pools with cold water. Spawning normally occurs between mid August and early October, peaking in September (Moyle 2002, as cited in NMFS 2009). Spring run fry emerge from the gravel from November to March (Moyle 2002). Juveniles may reside in freshwater for 12 to 16 months, but some migrate to the ocean as young of the year in the winter or spring months within 8 months of hatching (CALFED 2000, as cited in NMFS 2009). Winter Chinook salmon are unique because they spawn during summer months when air temperatures approach their yearly maximum. As a result, they require reaches with cold water sources to protect embryos and juveniles. Winter Chinook are primarily restricted to the mainstem Sacramento River. Adult immigration and holding (upstream spawning migration) through the Delta and into the lower Sacramento River occurs from December through July, with a peak from January through April (USFWS 1995, as cited in NMFS 2009 Recovery Plan). Winter run Chinook salmon are sexually immature when upstream migration begins, and they must hold for several months in suitable habitat prior to spawning. Primary spawning areas are in the mainstem Sacramento River between Keswick Dam (RM 302) and RBDD (RM 243). Spawning occurs between late April and mid August, with a peak generally in June. Fry rear in the upper Sacramento River, exhibiting peak abundance in September, with fry and juvenile emigration past RBDD from July through March (although NMFS [1993; NMFS 1997] reports juvenile rearing and outmigration extending from June through April). Except for Central Valley winter Chinook, which are largely restricted to the mainstem Sacramento River between Keswick Dam and RBDD, the existing Central Valley fall Chinook population is unique among North American Chinook ESUs in having little or no detectable geographically structured genetic variation (Williamson and May 2005; Banks et al. 2000). The degree of this diversity in the historical population is unknown, although it was almost certainly much greater than at present (Lindley et al. 2009). Central Valley late-fall run Chinook are genetically distinguishable from fall run Chinook, yet they are closely related and have been included in the same ESU (Myers et al. 1998). Page 12 Feather River Hatchery Spring Chinook Program / June 2012

19 For this review, existing Central Valley fall-run and late fall-run Chinook populations were defined based on populations described in the CDFG Grand Tab worksheet. Populations included in the analysis were those reported in the last 5 years to have fall or late fall run Chinook and are consistent with those described in ICF Jones & Stokes (2010) (Table 2). Table 2. Populations in the Central Valley fall and late-fall Chinook ESU, ordered from north to south (unlisted ESU). Population Sacramento River Fall Chinook (natural) Clear Creek Fall Chinook (natural) Cow Creek Fall Chinook (natural) Cottonwood Creek Fall Chinook (natural) Battle Creek Fall Chinook Battle Creek Late-Fall Chinook Mill Creek Fall Chinook (natural) Deer Creek Fall Chinook (natural) Butte Creek Fall Chinook (natural) Feather River Fall Chinook uba River Fall Chinook (natural) American River Fall Chinook Mokelumne River Fall Chinook Stanislaus River Fall Chinook (natural) Tuolumne River Fall Chinook (natural) Merced River Fall Chinook Location Sacramento River Sacramento River Sacramento River Sacramento River Sacramento River Sacramento River Sacramento River Sacramento River Sacramento River Sacramento River Sacramento River Sacramento River San Joaquin River San Joaquin River San Joaquin River San Joaquin River Historically, there were 19 independent populations and eight dependent populations of spring Chinook salmon in the Central Valley (Lindley et al. 2004). Currently, there are three independent (Butte, Mill, and Deer) and seven dependent (Antelope, Battle, Big Chico, Clear, Thomes, Cottonwood/Beegum, and Stony) populations remaining, along with one other hatchery natural integrated population in the Feather River and one other population in the Sacramento River below Keswick Dam (Table 3). Currently, the Sacramento River winter-run Chinook salmon ESU consists of a single (independent) population in the mainstem Sacramento between Keswick Dam and RBDD. The current conditions of each of the populations that could be affected by the FRH Chinook programs are described in Appendix B. The Feather River spring and fall Chinook runs are described below. Table 3. Populations in the Central Valley spring Chinook ESU, ordered from north to south (ESA listed threatened). Population Classification Clear Creek Spring Chinook (natural) Dependent Beegum-Cottonwood Spring Chinook (natural) Dependent Battle Creek Spring Chinook (natural) Other Sacramento River Spring Chinook (natural production above Red Bluff Diversion Dam) Antelope Spring Chinook (natural) Dependent Other Dependent Feather River Hatchery Spring Chinook Program / June 2012 Page 13

20 Population Classification Mill Creek Spring Chinook (natural) Independent Thomes Spring Chinook (natural)** Dependent Deer Creek Spring Chinook (natural) Independent Stony Creek Spring Chinook (natural)* Dependent Big Chico Spring Chinook (natural) Dependent Butte Creek Spring Chinook (natural) Independent Feather River Spring Chinook (integrated) Other * Because there are no data available for Stony Creek spring-run Chinook in CDFG s GrandTab database, this population is not included in our description of affected natural populations. ** Thomes Creek was excluded from our description of affected natural populations because only two spring Chinook have been documented here in the past 10 years Feather River Spring and Fall Chinook Populations The Upper Feather River watershed includes all tributaries to the Feather River from the headwaters in the Sierra Nevada crest downstream to Lake Oroville. The Upper Feather is a major source of the state s water supply and provides virtually all the water delivered by the California State Water Project. Most of the watershed lies in Plumas County and is roughly 65% publicly owned, primarily by the US Forest Service. The lower Feather River watershed, downstream of Lake Oroville (a fish migration barrier), encompasses about 803 square miles. The river flows approximately 60 miles north to south before entering the Sacramento River at Verona. There are approximately 190 miles of major creeks and rivers, 695 miles of minor streams, and 1,266 miles of agricultural water delivery canals in the lower Feather River watershed. Flows are regulated for water supply and flood control through releases at Oroville Dam. The river is almost entirely contained within a series of levees as it flows through the agricultural lands of the Sacramento Valley. Significant management issues include concerns over growth (farmland conversion to urban uses), demands on water supply, preservation of water quality and aquatic habitat, and potential risks from fire and floods. Historically, the Feather River supported both spring and fall Chinook salmon and was renowned as one of the major salmon-producing streams of the Sacramento Valley (oshiyama et al. 2001). The major spawning areas extended from the river s mouth to Oroville (oshiyama et al. 2001), a distance of over 60 miles, with important spawning areas continuing upstream. Fry (1961 as cited in oshiyama et al. 2001) reported annual fall Chinook runs of 10,000 to 86,000 fish from 1940 to1959, and about 1,000 to 4,000 spring Chinook. The fall run spawned largely in the mainstem, while most of the spring run spawned in the Middle Fork, with a few spring run entering the North Fork, South Fork and West Branch. Just before the completion of Oroville Dam (in 1967), a small naturally-spawning spring Chinook population still existed in the Feather River, but the Oroville project blocked access to the majority of its habitat. Currently, the fall run extends to Oroville Dam (RM 68) and spawns from there downstream to a point about 2 miles above the Gridley Road crossing (RM 51). There is also a hatchery-sustained population of spring-run fish that has been genetically mixed with the fall run and that spawns in the 0.5-mile reach below the Oroville fish barrier. The hybrid springrun fish hold over the summer in deep pools in the low-flow section of the river between Thermalito Diversion Dam (5 miles below Oroville Dam) and the downstream Thermalito Afterbay Outlet. They are spawned artificially in the FRH and also spawn naturally in the river during late September to late October. The spring run thus overlaps temporally as well as spatially with the fall run, which is the cause of the hybridization between the runs (oshiyama et al. 2001). Page 14 Feather River Hatchery Spring Chinook Program / June 2012

21 The FRH, located at the town of Oroville, was completed in 1967 by the California Department of Water Resources (DWR) to mitigate for the loss of upstream spawning habitat of salmon and steelhead due to the building of Oroville Dam. The FRH is the only source of eggs from springrun Chinook salmon in the Central Valley and is viewed as a key component in plans to restore spring Chinook populations (oshiyama et al. 2001). In recent decades, the majority of Chinook salmon production in the Feather River has been heavily supported by hatchery production. Since 2001, both spring-run and fall-run Chinook salmon escapement to the FRH has averaged approximately 15,000 fish (Table 4). During this same period, river returns (natural spawners) averaged approximately 79,000 fish. Approximately two-thirds of natural fall Chinook spawning occurs between the Fish Barrier Dam and the Thermalito Afterbay Outlet (RM 67 - RM 59), and one-third of the spawning occurs between the Thermalito Afterbay Outlet and Honcut Creek (RM 59 - RM 44). ICF Jones & Stokes (2010) concluded that approximately 82% of the natural fall-run Chinook spawners and 91% of the natural spring-run Chinook spawners in the Feather River basin are considered to be hatchery origin-fish. Table 4. Chinook salmon escapement in the Feather River basin ( ). ear Feather River 1 Percent In-River Feather River In-River Total (Feather) Hatchery , , , % , , , % ,976 89, , % ,297 54,171 75, % ,405 49,160 71, % ,034 76,414 90, % ,341 21,886 27, % ,082 5,939 11, % ,963 4,847 14, % ,972 44,914 64, % Average 15,845 63,109 78, % Source: 1 Note: Feather River survey data does not provide separate estimates for fall and spring escapement. Spring-run estimates are included with fall-run estimates. 2.2 Long term Goals for Natural Populations NMFS has classified Feather River spring Chinook as a Core 2 population. A Core 2 population must meet the following moderate risk extinction criteria: Census population size is 250 to 2,500 adults, or the effective population size is 50 to 500 adults, Productivity: Run size may have dropped below 500, but is stable, No catastrophic events occurred or are apparent within the past 10 years. According to the Anadromous Fish Restoration Plan (AFRP) (USFWS 2001), the spring Chinook production target for the Feather River is 170,000 (harvest plus spawning escapement). The AFRP defines natural production and other key terms used to interpret and measure whether the goal has been achieved as follows: Feather River Hatchery Spring Chinook Program / June 2012 Page 15

22 Natural Production: Fish produced to adulthood without direct human intervention in the spawning, rearing, or migration processes. Natural production should be self-sustaining. The program should not depend on hatchery-produced fish to sustain populations of naturally spawning fish. Sustainable: This is defined as capable of being maintained at target levels without direct human intervention in the spawning, rearing or migration processes. Direct Human Intervention: Hatchery and artificial propagation, including supplementation and out-planting of eggs or any other life-stage, requires handling of fish by humans during the spawning and rearing processes and therefore are forms of direct intervention. Title 34 of the Central Valley Project Improvement Act clearly states that fish produced with direct human intervention should not be included in counts of natural production. Counting: All naturally produced adult fish shall be counted, including those that are harvested prior to spawning. 3 Fisheries Affected by the Hatchery Program 3.1 Current Status of Fisheries For brood years , total survival (catch in all fisheries plus escapement) ranged from 0.5 to 2.55% for fingerling releases from the FRH based on coded-wire tag recoveries (Table 5). The simple average of total survival across brood years and release locations was 1.56% (average of values in Table 5). Average weighted survival based on numbers of tagged fish by release group (total number of CWT recovered/total number released) was 1.38% for brood years The average total exploitation rate across these brood years was 53% ( Table 5. Total percent survival (catch plus escapement) and exploitation rates for FRH spring Chinook brood years Brood ear Smolts Average Total Exploitation 53.0% Rate 1 Includes all age classes of recoveries, un-weighted average Source: The SAR for spring Chinook brood years released from FRH Hatchery at different release sites are presented in Table 6. Survival rates vary significantly by release location and brood year. The range of SARs for fingerlings was 0.017% (2003 brood) for fish released in the Feather River to 2.55% (1998 brood) for fish released from Crockett. All released fish were between 37 and 112 fpp (average 59 fpp). Page 16 Feather River Hatchery Spring Chinook Program / June 2012

23 Table 6. Total percent survival of spring Chinook reared at FRH by release location (catch plus escapement). Location Brood ear Crockett 2.55 San Pablo Bay Rodeo Minor Port 1.45 Wickland Oil Net Pen 0.46 Feather River at Live Oak Benicia 2.8 Feather River Figure 2 depicts the distribution of Feather River spring Chinook CWT expanded recoveries in fisheries and in spawning areas for brood years (averages are shown). Among fisheries, the largest percentage of CWT recoveries occurred in the California ocean troll fisheries (19%), followed by California ocean sport (11%) and Oregon ocean troll (10%). An estimated 33% of total recoveries occurred on natural spawning grounds and 12% returned to hatchery facilities. Small numbers of recoveries (less than 2% in each fishery) were also reported in Oregon (ocean sport) and Washington state fisheries (treaty Indian troll, non-treaty ocean troll, and ocean sport). The percentage of 2-year-old recoveries (all fisheries plus escapement) averaged 12% of the total recoveries. ODFW 10 Ocean Troll 10% CDWR 54 Spawning Ground 17% All Jacks 12% CDFG 10 Ocean Troll 19% CDFG 40 Ocean Sport 11% CDFG 54 Spawning Ground 16% CDFG 50 Hatchery Escapement CDFG 46 12% Freshwater Sport 3% Figure 2. Feather River Spring Chinook- percent of total survival in various fisheries: brood years Feather River Hatchery Spring Chinook Program / June 2012 Page 17