June 2007 – CMSMON #1a

Cheakamus River Project Water Use Plan Juvenile Salmonid Outmigration Enumeration Assessment Spring 2007 Reference: CHEAKMON#1a Cheakamus River Water Use Plan Monitoring Program: Juvenile Salmonid Outmigration Enumeration Assessment, Spring 2007 Study Period: February to June 2007 Caroline Melville and Don McCubbing R.P.Bio., InStream Fisheries Research Inc. Cheakamus River Juvenile Salmonid Outmigration Enumeration Assessment Spring 2007 Prepared for BC Hydro By Caroline Melville and Don McCubbing April 2008 Instream Fisheries Research Inc. 1698 Platt Crescent, North Vancouver, BC. V6J 1Y1 Tel 1-604-737-1510 E-mail don@instream.net Acknowledgements We thank the North Vancouver Outdoor School, Fisheries & Oceans Canada, and the Ministry of Environment for their continued support and cooperation. We would specifically like to acknowledge Carl Halvorson (Site Manager; North Vancouver Outdoor School) and Peter Campbell (Manager, Tenderfoot hatchery; Fisheries and Oceans Canada) for their logistical support. Thank-you to our field technicians; Heath Zander, Russ Jacobs, LJ Wilson and Wiley George for their dedication to the study. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Executive Summary In 2000 a juvenile outmigration salmonid monitoring program was initiated by the Cheakamus Water Use Plan Consultative Committee to evaluate anadromous fish productivity in the Cheakamus River under the Interim Flow Agreement. As a continuation of this monitoring program juvenile outmigration of anadromous fish is now monitored as part of the evaluations of flow changes implemented under the Water Use Plan, initiated on this river in spring of 2006 (Cheakmon#1a). As part of the WUP monitoring program we evaluated smolt and fry outmigrants for five species of salmonids; coho salmon (Oncorhynchus kisutch), chum salmon (O. keta), chinook salmon (O.tshawytscha), pink salmon (O. gorbuscha) and steelhead trout (O.mykiss). In 2007, an estimated 4.63 million chum fry, 150,374 chinook fry and 85,018 coho smolts were produced in the area of the Cheakamus River upstream of the monitoring site at the North Vancouver Outdoor School (NVOS) property. No estimates were formed for chinook smolts and steelhead smolts due in part to low capture numbers. Pink salmon were virtually absent in the sample data, as 2006 was an off-year for spawners. The estimated chum production estimate was the highest recorded since monitoring commenced in 2000. Coho smolt and chinook fry production was the second highest recorded, with only 2003 producing greater numbers of fish. Steelhead smolt estimates have not been generated in 4 of 8 years and not since the high water event in October 2003. Despite this potential indication of low smolt yield, adult escapements as observed by swim survey (CheakMon#3) have remained high (circa 300-400 fish), indicating a potentially complex relationship between observed smolt abundance in the rotary screw traps (RSTs) catch and actual smolt yield. Incidental catch of parr at the (RSTs) in 2007 indicated a possible trend of increasing abundance in O.Mykiss with the highest numbers recorded in all survey year. Average coho smolt length was lower in 2007 than in previous years, perhaps indicating some density dependant growth threshold had been reached as the year of greatest size (2006) was associated with the lowest recorded production estimate of just 21,602 smolts. Insufficient data are available for steelhead and chinook smolts in 2007 to evaluate growth differences amongst years. Side- channel production estimates were attempted for coho smolts and chum fry in 2007. Data confidence in side channel productivity of coho smolts from Upper Paradise channel (full trap) was low due to novel methods used (electronic enumeration) and yet require additional site development for accurate enumeration. Chum fry production in the Upper Paradise complex on the NVOS property was estimated to represent 36% of total chum production above the main river monitoring site. Additional non main stem chum fry production will also be contributed from BC Rail channel, Mile 49 channel and Tenderfoot Creek, indicating the importance of these off channel spawning areas in total upper river (above kilometer 4) production of this species. While variance between sample years of production estimates appear much greater than annual estimate precision, additional data collection and modeling of estimates are being undertaken to verify these assumptions and evaluate potential bias in data collection and analysis methods. InStream Fisheries Research Inc. Page i Table of Contents 1.0  INTRODUCTION ............................................................................................................... 1  1.1  Study Area and Trapping/Enumeration Locations ......................................................... 3  1.2  Hatchery Releases ......................................................................................................... 3  2.0 METHODS ................................................................................................................................ 5  2.1  Fish Trap Operations ...................................................................................................... 6  2.1.1  Rotary Screw Traps .................................................................................................. 6  2.1.2  Side-channel Fyke Net Traps ................................................................................... 7  2.1.3   Complete Channel Traps .......................................................................................... 7  2.1.4   Resistivity Fish Counters ......................................................................................... 8  2.1.5   Resistivity Counter Video Validation ...................................................................... 9  2.2 Planned Expansion of Trapping Operations. ......................................................................... 9  2.3 Biophysical Sampling .......................................................................................................... 10  2.4 Fish Marking........................................................................................................................ 10  2.5 Fish Sampling ...................................................................................................................... 13  2.6 Data Analysis...................................................................................................................... 14  2.6.1 Mark Recapture ...................................................................................................... 14  2.6.2   Fish Counter Data Analysis ................................................................................... 15  3.0 RESULTS ............................................................................................................................ 16  3.1 Trap, Counter and Fyke Net Operations .............................................................................. 16  3.1.1   River discharge and trapping/counter operations ................................................... 16  3.1.2   Hatchery releases and trapping/counting operations.............................................. 17  3.2 Biophysical Monitoring ....................................................................................................... 18  3.3 Mainstem Chum Fry Migration and Production .................................................................. 18  3.3.1   Chum Fry Length ................................................................................................... 20  3.4 Side-channel Chum Fry Migration and Production ............................................................. 20  3.4.1   Upper Paradise/Gorbushca Complex Chum Migration and Production ................ 20  3.4.2   Kisutch Groundwater Channel Chum Migration and Production .......................... 20  3.4.3   Upper Paradise Groundwater Channel Chum Migration and Production .............. 21  3.5 Pink Fry Migration .............................................................................................................. 22  3.6 Chinook Fry and Smolts ...................................................................................................... 22  3.6.1   Chinook Fry Migration and Production ................................................................. 22  3.6.2   Chinook Smolt Migration and Production ............................................................. 23  3.6.3   Chinook Length and Age Data............................................................................... 23  3.7 Steelhead Parr and Smolts ................................................................................................... 24  3.7.1   Mainstem (RST) Steelhead Smolt Migration and Production ............................... 24  3.7.2   Mainstem (RST) Steelhead Parr Migration and Production .................................. 24  3.7.3  Side Channel Steelhead Migration and Production ............................................... 24  3.7.4   Steelhead Lengths and Weights ............................................................................. 24  3.8 Mainstem Coho Smolt and Fry Migration & Production .................................................... 24  3.8.1   Coho Smolts ........................................................................................................... 24  3.8.2   RST Marked Coho ................................................................................................. 25  3.8.3   Side-Channel Marked Coho ................................................................................... 26  3.8.4  Coho Lengths ......................................................................................................... 27  3.9 Side Channel Coho Smolt Yield .......................................................................................... 27  3.9.1   Kisutch Channel Fish Counter ............................................................................... 27  3.9.2  BC Rail Channel Fish Counter............................................................................... 28  3.9.3   Tenderfoot Creek Fish Counter.............................................................................. 29  3.9.4   Upper Paradise Channel Smolt Trap ...................................................................... 30  3.9.5   Upper Paradise Groundwater Channel Smolt Trap ................................................ 30  Page ii InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Table of Contents (cont.) 4.0 DISCUSSION .......................................................................................................................... 31  4.1 Fish Trap Operations ........................................................................................................... 31  4.2 Juvenile Outmigration Yield ............................................................................................... 31  4.2.1  Data Analysis ......................................................................................................... 31  4.2.2   Chum Fry Migration .............................................................................................. 32  4.2.3   Chinook Juvenile Migration................................................................................... 33  4.2.4  Steelhead Juvenile Migration ................................................................................. 35  4.2.5  Mainstem Coho Smolt Production ......................................................................... 37  4.2.6  Restoration Channel Coho Smolt Production ........................................................ 38  5.0 SUMMARY AND RECOMMENDATIONS .......................................................................... 40  6.0 TABLES .................................................................................................................................. 44  7.0 FIGURES ................................................................................................................................. 55  8.0 REFERENCES ........................................................................................................................ 81  McCubbing, D. and G. Andrusak. 2006. Lardeau River Fish Counter 2006 Gerrard Rainbow Trout Enumeration Report. HCTF Technical Report 22p. ...................................................................... 82  APPENDICES ............................................................................................................................... 85  Appendix 1-A. Mainstem (RST) Catch and Population Estimate Summary: Spring 2007. ...... 85  Appendix 1-B: Side-channel Catch and Population Estimate Summary: Spring 2007. ............ 87  Appendix 2-A: Mainstem Chum Fry Mark and Recovery Strata: Spring 2007. ....................... 88  Appendix 2-B: NVOS Side-channel (Site F) Chum Fry Mark and Recovery Strata: Spring 2007. ................................................................................................................................................... 89  Appendix 2-C: Kisutch Ground Water Channel (Site D) Chum Fry Mark and Recovery Strata: Spring 2007. .......................................................................................................................................... 90  Appendix 2-D: Upper Paradise Ground Water Channel (Site B) Chum Fry Mark and Recovery Strata: Spring 2007. .............................................................................................................................. 91  Appendix 2-E: Mainstem Chinook Fry Mark and Recovery Strata: Spring 2007. .................... 92  Appendix 2-F: Mainstem (RST) Coho Smolt Mark and Recovery Strata: Spring 2007. .......... 93  Appendix 2-G: Mainstem (Upper Paradise) Coho Smolt Mark and Recovery Strata: Spring 2007. ................................................................................................................................................... 94  InStream Fisheries Research Inc. Page iii   Table 1. Start and end dates for all traps and counters operated on the Cheakamus River, Spring 2007. ............................................................................................................................................... 44  Table 2. Annual dates of 90% capture of chum, chinook, and pink fry at the RST site on the Cheakamus River, 2001 to 2006. .............................................................................................................. 45  Table 3. Trap dates for which trap operation was limited or suspended (1 day = 24 hrs). ............ 45  Table 4. Eight year summary of fish caught and marked at the rotary screw trap and side-channels on the Cheakamus River................................................................................................................... 46  Table 5. Summary of size ranges for age classes of salmonid and trout species on the Cheakamus River, Spring 2007 ........................................................................................................................... 50  Table 6. Summary of length & weight data from fish captured at the rotary screw traps on the Cheakamus River, Spring 2007. ............................................................................................................... 51  Table 7. Summary of mean lengths 2000-2007 from the Cheakamus River. ................................ 52  Table 8. Preliminary estimates of coho smolt migration from Cheakamus side-channel electronic counters & traps, Spring 2007. ............................................................................................................ 54  List of Tables   Figure 1. Cheakamus River watershed indicating Reaches 1 through 9, WSC gauging station, temperature loggers, and RST trap location. ............................................................................................. 55  Figure 2. Site Map indicating trap sites utilized in 2007 on the Cheakamus River. ...................... 56  Figure 3. Diagram of side-channel fry production marking and enumerator sites in the Upper Paradise/Gorbushca side-channel complex, Spring 2007. .................................................... 57  Figure 4. Diagram of side-channel smolt production trap and counter sites, Spring 2007. ........... 58  Figure 5. Diagram of Cheakamus mainstem fry production estimate marking and recapture sites, Spring 2007. ...................................................................................................................................... 59  Figure 6. Diagram of Cheakamus mainstem smolt production estimate marking and recapture sites, Spring 2007. .......................................................................................................................... 60  Figure 7. Mean Daily Discharge from Water Survey of Canada Station 08GA043 Cheakamus at Brackendale. Spring 2007. .................................................................................................... 61  Figure 8. Average Daily Water Temperature in oC, of the Cheakamus River, as recorded by a logger located at the trap site, Spring 2007. ..................................................................................... 62  Figure 9. Weekly catch summary of chum fry (solid line, squares) related to temperature in oC (broken line, triangles) and discharge (solid line) from the Cheakamus River, Spring 2007. ............ 63  Figure 10. Weekly catch summary of chinook fry (solid line, squares) related to temperature in oC (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007......................... 64  Figure 11. Length frequency distribution of chinook juveniles from the Cheakamus River, Spring 2007. ............................................................................................................................................... 65  Figure 12. Weekly catch summary of steelhead smolts (solid line, squares) related to temperature in oC (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007. .......... 66  Figure 13. Weekly catch summary of steelhead parr (solid line, squares) related to temperature in oC (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007. .......... 67  Figure 14. Length frequency distribution of steelhead juveniles sampled on the Cheakamus River, Spring 2007. ...................................................................................................................................... 68  Figure 15. Weekly catch summary of coho smolts (solid line, squares) related to temperature in oC (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007......................... 69  Figure 16. Weekly catch summary of coho fry (solid line, squares) related to temperature in oC (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007......................... 70  List of Figures Page iv InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   List of Figures (cont.) Figure 17. Length frequency distribution of coho juveniles from the Cheakamus River, Spring 2007. ............................................................................................................................................... 71  Figure 18. Peak Signal Size of Records at the Kisutch channel fish counter, Spring 2007. .......... 72  Figure 19. Up, event and down counts of fish with PSS <80 at Kisutch channel, Spring 2007. ... 72  Figure 20. Up, event and down counts of fish with PSS <80 at BC Rail channel, Spring 2007. .. 73  Figure 21. Up, event and down counts of fish with PSS >80 at BC Rail channel, Spring 2007. .. 73  Figure 22. Pooled Petersen Estimates of chum fry from Spring 2000 to 2007, including 95% confidence limits. ..................................................................................................................................... 74  Figure 23. Pooled Petersen Estimates of chinook fry from Spring 2001 to 2007, including 95% confidence limits. ..................................................................................................................................... 75  Figure 24. Pooled Petersen Estimates of chinook smolts from Spring 2000 to 2007, including 95% confidence limits. .................................................................................................................. 76  Figure 25. Pooled Petersen Estimates of steelhead smolts from Spring 2000 to 2007, including 95% confidence limits. .................................................................................................................. 77  Figure 26. Pooled Petersen Estimates of coho smolts captured and marked at the RST site from Spring 2000 to 2007, including 95% confidence limits. ................................................................... 78  Figure 27. Pooled Petersen Estimates of mainstem coho smolts out-migration, calculated using coho smolts captured and marked at the side-channels from Spring 2000 to 2007, including 95% confidence limits. .................................................................................................................. 79  Figure 28. Comparison of population estimates of coho smolts derived from RST marked fish (solid black bar) and side-c hannel marked fish (diagonal striped bar) from 2001 to 2007 on the Cheakamus River. ..................................................................................................................................... 80  InStream Fisheries Research Inc. Page v Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   1.0 INTRODUCTION The Cheakamus River watershed is a major tributary of the Squamish River and drains upstream of Brackendale gauging station, an area totaling 1010km2 of the Coastal Mountain range in south-western BC. River discharge is affected by BC Hydro through operation of Daisy Reservoir and the Cheakamus generating plant, a 155 MW storage and diversion project. The generation project, completed in 1957, consists of a 28m high, 680m long dam that impounds Daisy Reservoir. From this reservoir, a portion of the river flow is diverted through an 11km long tunnel to a powerhouse on the Squamish River. The Cheakamus River, downstream of the reservoir, extends 26km to its confluence with the Squamish River. Only the lower 17km of this river are accessible to anadromous salmon as a number of natural barriers preclude further upstream migration (Figure 1). The Cheakamus River anadromous mainstem habitat is complimented by a large area of man-made restoration channels which are fed either by groundwater or river water diverted from the mainstem. In 1999 the Cheakamus Water Use Planning (WUP) process identified the need to determine the response of juvenile salmonid populations to an Interim Flow Order (IFO) which was implemented in 1997. A juvenile salmon outmigration study utilizing rotary screw traps commenced in the spring of 2000 (Melville & McCubbing, 2001) and has continued annually through 2007. In 2005 the Cheakamus River WUP (BC Hydro, 2005) presented a matrix of discharge arrangements for Water Comptroller approval. The WUP incorporates a number of discharge rules for the Cheakamus River designed to balance environmental, social and economic values. As a fundamental objective of the Cheakamus River WUP is to maximize wild fish populations, the proposed changes to the existing IFO were based in part on expected benefits to wild fish populations (BC Hydro, 2006). The new flow order for the Cheakamus River was approved by the Water Comptroller and implemented on February 26th, 2006. InStream Fisheries Research Inc. Page 1 Under the implemented WUP, the discharge rules for operations were varied from the existing 45% of previous day inflows requirement (IFO) to a required minimum measured flow at the following two locations: 1) Minimum required flow below Daisy Lake Dam: i) 3.0 m3/s from Nov 1 to Dec 31 ii) 5.0 m3/s from Jan 1 to Mar 31 iii) 7.0 m3/s from Apr 1 to Oct 31 2) Minimum required flow at the Brackendale gauge: i) 15.0 m3/s from Nov 1 to Mar 31 ii) 20.0 m3/s from Apr 1 to Jun 30 iii) 38.0 m3/s from Jul 1 to Aug 15 iv) 20.0 m3/s from Aug 16 to Aug 31, unless directed by Comptroller to maintain 38.0 m3/s for recreation v) 20.0 m3/s from Sep 1 to Oct 31 The likely effects on fish populations of the new operating regime are uncertain because the benefits presented during the WUP process were modeled using complex relationships between fish habitat and flow, and assumed relationships between fish habitat and fish production (Marmorek & Parnell, 2002). The Juvenile Outmigration Monitor in conjunction with other monitors will help to reduce this uncertainty and monitor potential effects of the new flow regime on salmon populations. This year, 2007, the study was expanded to include population assessments of salmonids from key restoration side channels to better answer two key management questions: 1. What is the relation between discharge and juvenile salmonid production, productivity, and habitat capacity of the mainstem and major side channels of the Cheakamus River? 2. Does juvenile salmonid production, productivity, or habitat capacity change following implementation of the WUP flow regime? Page 2 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   In addition, outmigrant data from this program will be used as part of the Groundwater Side-channels Monitor (Cheakamus Water Use Plan Monitoring Program Terms of Reference, Feb 2007, Monitor #6) to address the management question: • To what extent does salmonid production vary in North Vancouver Outdoor School (NVOS) and Tenderfoot Hatchery (TH) side channels in relation to groundwater flow interaction with the Cheakamus River when discharge is < 40m3/s, and to what extent has the implementation of the WUP affected salmonid production in the NVOS and TH side-channel habitats compared to the pre-WUP state. The expanded study includes detailed assessment of juvenile salmonid outmigraton using a combination of total capture, mark-recapture and estimated counts from resistivity counters; the choice of methodology is based on the site and the age class of the fish being assessed. This report presents the methods, results and recommendations from the first year of the expanded study. 1.1 Study Area and Trapping/Enumeration Locations The primary location of fish enumeration consisted of rotary screw traps (RSTs) operated adjacent to the North Vancouver Outdoor School (NVOS) property (10U 0489141:5518035, Figure 1 & 2) at river kilometer (RK) 5.5. Secondary enumeration sites were operated on both river augmented and ground water side-channels at locations on the NVOS property (various locations, Figure 2), on BC Rail channel (10U 0489301:5519270, Figure 2) and on Tenderfoot Creek (10U 048392:5519514, Figure 2). 1.2 Hatchery Releases Releases of hatchery fish are undertaken annually into the Cheakamus River by various organizations. In 2007, hatchery 1+ coho and chinook young of the year (YOY) were released into the Cheakamus River at various locations by Fisheries and Oceans Canada (FOC, Tenderfoot Hatchery, Figure 2). Chum fry were released by the North Vancouver Outdoor School Hatchery (NVOS) into Upper Paradise side-channel complex (Figure 2), and the Ministry of Environment released steelhead smolts into the Cheakamus River at various locations above and below the enumeration locations. Due to observed losses of chinook adults following the caustic soda spill (McCubbing et al., 2006), a hatchery enhancement program targeting Cheakamus chinook was implemented in the fall of 2005. InStream Fisheries Research Inc. Page 3 Chinook salmon adults are captured in the river and placed in Tenderfoot Hatchery (TH) where they are spawned and their progeny raised and released the following spring as young-of-the-year (YOY). These YOY are released to the Cheakamus mainstem at RK 12 to 15. This varies from TH practice prior to fall 2005 in this watershed when all chinook brood collection and young release occurred in Howe Sound. Coho 1+ smolts are released every spring directly from TH into Tenderfoot Creek. These fish are marked with an adipose clip and can be easily identified. In 2007, unlike in previous years, additional unmarked coho smolts were also released at RK 12-15. As for chinook YOY the RK 12-15 coho are being released to mitigate losses observed during the caustic soda spill in 2005 (McCubbing et al., 2006). Due to the abundance of released coho RST operations are suspended following releases, thus allowing the majority of the outmigrants to pass the RST site without the risk of capture. The number of fish that would be captured when passing the traps immediately after these hatchery releases is too great to facilitate sampling without risk of fish mortality. The NVOS Hatchery (Figure 2) releases a small number of chum fry each spring. Depending on release numbers, RST operation is occasionally suspended for one day to allow fish passage. This operational protocol has been established as hatchery chum fry cannot be differentiated from wild fry based on size or morphology and as chum fry migrate quite quickly (overnight) past the traps (C. Melville, pers. obs.). In 2007 hatchery steelhead smolts were released into the Cheakamus River for the first time since the study commenced in 2000. As with the mainstem coho and chinook releases, the steelhead hatchery program was implemented due to the steelhead mortality incurred in 2005 from the caustic soda spill. Page 4 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   2.0 METHODS Three methods were used for enumerating outmigrant salmonid fry and smolts from the Cheakamus River in 2007: 1) partial traps, RSTs and fyke nets which rely on mark recapture methodology to evaluate fry and smolt outmigration 2) complete channel traps, which allowed for manual counting of all outmigrant smolts from a designated area 3) resistivity counters built into diversion weirs, which electronically enumerate outmigrant smolts During study design a method was chosen based on the logistics of each trapping location. Considerations evaluated when choosing trapping methodology included species life-stage (i.e. fry or smolt), number of fish that can reasonably be enumerated during a 24 hour sample period (i.e. fry), potential stress and mortality of fish (i.e. ensuring that the method reduced the risk of mortality to the population), manpower requirements, and environmental factors (i.e. flow and location). Unlike total capture or electronic enumeration methods which aim to count all of the fish passing the enumeration location, mark recapture methods estimate the number of outmigrants by sampling only a portion of the total fish passing the trapping/counting location. To determine the actual number of fish passing downstream in a given sample time period, a known number of marked fish are released into the population upstream of the enumerating location with the assumption that these fish will move downstream and pass the enumeration station (RST or fyke net) and that a portion of these fish will be recaptured. Assuming that fish do not lose their marks before recapture, that no marks are missed during sampling, and that the chance of capturing any marked fish is equal to unmarked fish, the efficiency of a capture trap can be calculated for a given time period (Seber, 1982; AFS 2007). These data are then used to statistically model the numbers of outmigrants actually passing the trap location during each sample period. Factors which may confound such estimates include residualization of marked fish, loss of mark fish to predators, or marked fish bypassing the enumeration site without the potential for capture (AFS, 2007; Frith et al., 1995). Our study design utilizes best practice methods to minimize the risk of challenging these assumptions, which include but are not limited to: marking fish while minimizing handling stress, avoiding fish releases that may encourage predation (i.e. avoiding day time marking and InStream Fisheries Research Inc. Page 5 release), and using marking traps separate from recapture traps where practicable to reduce fish transport stress. 2.1 2.1.1 Fish Trap Operations Rotary Screw Traps RST trapping methods for the Cheakamus follow those outlined in Melville & McCubbing, 2001 & 2002a. Briefly, emigrating salmonid juveniles are captured in the mainstem of the Cheakamus River at RK 5.5 using two six-foot diameter rotary screw traps during the sampling period from February 15th to June 15th (Table 1). Each RSTs is checked a minimum of twice per day (morning and evening) – once to bio-sample fish and mark smolts, and the second time to mark fry and ensure proper trap operation. Frequency of RST checks and maintenance are increased when flow and fish numbers warrant, minimizing trap-induced mortality and insuring optimal trap operation. RSTs are monitored continuously when flows approach their operational threshold of 50 m3/s. If flows continued to rise beyond 50 m3/s trap operations are suspended for safety reasons and traps are brought to shore until water levels recede to a level where the risk of trap loss is minimal. In 2007, a change to operational procedures was placed in effect in an effort to increase trap operating efficiency in late May and early June. With lengthening days and increased sunlight, conditions are typically dominated by higher discharges due to high elevation snowmelt and also by increased algal growth which clogs screens during this time period. As this results in a reduced ability to operate traps with small mesh drums (Melville & McCubbing, 2006), 1/8” mesh screen drums were replaced by larger 1/2” mesh on May 18th 2007 in order to reduce screen surface area and thereby reduce resistance to water flow as well as minimize clogging due to algal and debris build up. This should allow for more efficient trap operation, particularly at higher discharge. However, though this may improve the capture of smolts, the capture of chum, pink or chinook fry were expected to be reduced. Therefore, to avoid reduction in precision of yield estimates as a result of reduced capture efficiencies for these fry, the date change for mesh size was selected for on or after May 15th after which, based on data collected in previous years (2001 to 2006), <10% of fry captures occur (Table 2). Page 6 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   2.1.2 Side-channel Fyke Net Traps Side-channel fry production upstream of the RST site was estimated at a number of sites in the Upper Paradise channel complex by deploying fyke net traps (Figure 2). The fyke nets (1/8” mesh) had openings of 1m by 1m tapering down to a 6” tube which was attached to a capture box. A total of 8 fyke net traps were utilized through the study period. In an effort to minimize handling stress separate upstream capture nets (herein referred to as marking traps) were used to obtain fish for marking. These fish were released at the site of marking with a portion being captured in downstream traps (herein referred to as enumerator traps), allowing a population estimate to be derived using the mark-recapture methods as described in Section 2.6.1. The upstream marking fyke traps were operated for 4 days per week while the downstream enumerator traps operated 7 days per week. Dates of operation varied for each location in 2007, based on gear availability and deployment (Table 1). Operation of the fyke nets was suspended when daily catch at the enumerator traps approached zero. Estimates of fry production from groundwater only channels and river augmented flow-through channels were provided by operating marking fyke nets on Upper Paradise, Kisutch and Gorbushca channels (Sites A, C, E, H & G; Figure 2 & 3) and enumerator fyke nets on Upper Paradise (sites B & F; Figure 2 & 3) and Kisutch channels (site D; Figure 2 & 3). 2.1.3 Complete Channel Traps A juvenile smolt trap was operated as in previous study years (2001-2006) on the Upper Paradise channel (Trap Site 6; Figure 2). The primary objective of this trap has been to provide a large sample of coho smolts for marking to derive mark-recapture estimates at the RST site, as reported in 2001 through 2007 (Melville & McCubbing, 2002a & b, 2003, 2004, 2006, and 2007 data on file). It has also provided a count of all out-migrating smolts (but not fry) from the Upper Paradise channel and the portion of Farpoint channel which is diverted into Upper Paradise (Figure 2). In 2007 an additional complete capture trap (Trap Site 2; Figure 2 & 4) was operated at the downstream end of the groundwater section of Upper Paradise. This trap captured all smolts migrating from this section of the channel. InStream Fisheries Research Inc. Page 7 2.1.4 Resistivity Fish Counters Enumeration of smolt outmigration from Kisutch and BC Rail ground water channels and Tenderfoot Creek (Sites 3, 4 & 5; Figure 2 & 4) was undertaken through the operation of full river spanning weirs that direct fish to electronic counters. The Logie 2100C electronic counter (Aquantic Ltd, Scotland) is a resistivity counter. Briefly, the counter operates by detecting the passage of a fish across an array of three electrodes which the counter continually monitors (Nicholson et al., 1995). The counter monitors the resistance of the water between the counting array (bulk resistance) and calibrates for minor environmental changes in this resistance every 30 minutes. When a fish passes through the electrode array, a change in resistance occurs as a fish is more conductive than the water it displaces. This change of resistance is recorded and analyzed by the counter using a firmware algorithm to determine if it fits a typical fish pattern. Should the counter assess that a “fish” has passed over the array the time, direction of travel and peak signal size (change of resistance measurement), of the event is recorded and stored for later downloading and analysis (see Aprahamian et al., 1996, for more details of counter design and operation). Records are stored as up counts (U), down counts (D) or unqualified events (E). An event record is created when a change in resistance is recorded by the counter which does not adhere to the required pattern as to be defined a fish movement. Event records may occur due to background noise (air entrainment, electrical interference, etc.) or when a fish fails to trigger a signal above a predetermined threshold level. As with previous applications the counter required three electrode sensors (Aprahamian, 1996; McCubbing et al., 1999; McCubbing, 2003) to determine when fish passage occurs, in which direction and of what size. In this case the sensor electrodes were created as rings and placed in insulating plastic tubes of 15cm diameter at 10cm intervals from the center of the tube. The tubes were approximately 30cm long. Insulated wires connected the tubes with the Logie 2100C unit. The tubes were installed in a grid which separated the upstream and downstream section of the channels. The tubes were mounted with the upstream end of the tube flush with the separation grid to assist with fish passage. The Logie 2100C counters were operated through battery power on a continuous 24/7 basis. Data collected was stored as buffer files (on the counter) and downloaded on a regular basis by field staff. The data contains the date of download, settings of the counter, and any dummy fish data, followed by all event and fish records. Each record line contains the date, time, conductivity, channel of count, direction of travel (up or down) and estimated Peak Signal Strength (PSS) of the change in resistance. Page 8 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Example fish record: Date 25/04/2007 Time 9:46:23 Conductivity 100 Channel 1 Direction D PSS 35 2.1.5 Resistivity Counter Video Validation Video validation was undertaken to assess counter efficiency at the resistivity counter stations during smolt outmigration in May 2007. Time lapse video footage recorded at 10 frames per second (fps) was collected using a Capture DVMS 400 digital video recorder and underwater digital camera with infra-red illumination. Data were examined for fish passage and determination of species where possible. Similar studies in the United Kingdom (Fewings, 1987; Dunkley, 1991; Aprahamian et al., 1996) have shown the value of this video validation methodology. Counter efficiency is calculated as the numbers of fish counted divided by the number observed migrating on the video record and expressed as a percentage. Down and up count efficiency are evaluated separately. 2.2 Planned Expansion of Trapping Operations. Operation of a third RST was planned for Spring 2007 but as moorings for this RST are not yet constructed its operation was delayed. In 2007, smolt production from portions of the Upper Paradise side-channels were assessed using a combination of full capture fish traps and resistivity counters. In the future an assessment of total smolt production from this entire side channel complex will be undertaken (Site 1; Figure 2& 4). This site will be developed in Spring 2008. This work was not undertaken in Spring 2007 due to delays in approvals for construction of the sill at the new site as a result of “in-stream work windows” and local planning requirements. InStream Fisheries Research Inc. Page 9 2.3 Biophysical Sampling Five temperature loggers were installed into the mainstem Cheakamus River in February, 2007. The five locations are described as follows and are shown in Figure 1: 1) Downstream of Daisy Dam (upstream of Rubble Creek, RK 26, 10U 0489781:5535658) 2) Upstream of Cheakamus Canyon (anadromous barrier, RK 20, 10U 0489782:5535665) 3) Suspension Bridge (RK 13 upstream of Culliton, 10U 0486976:5525175) 4) Rotary Screw Trap site (RK 5.5 downstream of Culliton, 10U 0489141:5518035 ) 5) Downstream of Cheekye (RK 2, 10U 0487911:5515362) The temperature loggers will be operated for the full calendar year and for the duration of the Juvenile Monitor study (5-10 years). Loggers are downloaded once every month and the data are archived for use in other Cheakamus WUP monitors. The temperature data recorded at the Rotary Screw Trap (Temperature Logger 4) were used for analysis in this study. Mean daily and weekly discharge (Q) over the survey period was computed from the Water Survey of Canada (WSC) hourly discharge record for the Cheakamus River at Brackendale (WSC 08GA043), located 100m upstream of the RST site (Figure 1) . These readings are used for analysis in this study. 2.4 Fish Marking As previously described, mark recapture methods were used to assess capture efficiency of the RSTs and side-channel enumerator fyke traps. Capture efficiencies were then used to calculate population estimates of outmigrants. Since trap capture efficiencies are expected to vary over the migration period based on flow conditions, fish migration patterns and abundance as well as other factors, population estimates calculated using capture efficiency estimates over shorter time periods (strata) are likely to be more accurate than population estimates calculated using average capture efficiency over the entire migration period (Seber, 1982). This requires a planned marking regime where individual strata may be differentiated based on separation of mark groups. Chum and chinook fry marking procedure at the RSTs and the side-channel fyke nets in 2007 followed the same protocol as reported by Melville and McCubbing in 2005. Fry collected at the RSTs and at the marking fyke traps were not sampled in the morning of capture but held in the trap boxes until late afternoon. Page 10 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   A maximum (due to time constraints) of 3,000 fry were marked each day by immersion in Bismark Brown Y (BB) or Neutral Red (NR) dye at a concentration 1:100,000. Fish were immersed for 1 hour in 50 litres of dye solution aerated with medical grade oxygen. This marking technique was developed to minimize stress related mortality due to the marking/holding process on fry and at the same time reduce safety concerns relating to staff working at night (Melville & McCubbing, 2002b). Marking was restricted to the peak fry migration period (February 26th to May 13th) as recaptures of marked chum fry are often at or near zero when available fry for marking numbered less than 100 individuals per day. Such low recapture rates preclude the ability to calculate a robust efficiency estimate (Shwarz & Taylor, 1998). After marking fry were immediately released. RST marked fry were moved upstream to Eagle Point prior to release, while side-channel marked fish were released immediately downstream of marking fyke traps (Figure 2, 3 & 5). Marking and enumeration were timed such that each release of marked fry would coincide with dusk. This procedure was undertaken for four days each week (Monday through Thursday). A three-day break between marking periods has been assessed as sufficient to allow all marked fry from each four-day marking period to pass by the RSTs or enumerator fyke traps, thus requiring only one mark type. Historical recapture of marked fry has consistently approached zero within 48 hours after release in all years of this time series (data on file). Thus this method allows for calculations of weekly capture efficiency. Daily fry catch data collected at the RST on fry marking days represent the sample period from late afternoon through late afternoon. This differs from daily reported smolt catch at each site and the fry catch at side-channel enumerator sites where daily sample counts are evaluated in the morning. However, as visual observations since the study commenced in 2000 indicate few fry or smolts are captured during daylight hours at any trap, the daily sample totals are likely comparable. Smolt marking methods at the RST and Upper Paradise smolt trap (Site 6) were the same as in previous years (2001-2006; see Melville & McCubbing, 2001). Smolt marks (unique to a release group) refer to a combination of caudal fin mark(s) and the sub-dermal injection of a coloured dye using a jet inoculator (Hart & Pritcher, 1969). The fin mark was varied during the migration period to determine the efficiency of the traps through time (temporal stratification). Dates for each release group were determined at the start of the study based on previous years’ run timing and the mark was changed weekly or bi-weekly (1 week = Sunday to Saturday). The marking strategy is adaptive in nature and can be altered within the InStream Fisheries Research Inc. Page 11 field season based on changes in capture numbers, migration timing, and/or events such as high flow that precipitate a change in trap operation, as explained in Section 2.1.1. Prior to marking, smolts were anaesthetized in a bath of diluted clove oil dissolved in ethanol. Caudal fin clips were of two types, upper caudal (UC) and lower caudal (LC). The caudal fin was cut dorso-ventrally at a point approximately one-fourth the distance from the tip of the lobe to the caudal peduncle. Blue (alcian blue) or Red (neutral red) coloured dye was applied either to the upper or lower caudal peduncle, the pectoral fin, the ventral fin, or the anal fin with a jet inoculator. The mark was a line on the fin ray approximately 3-4mm long. Efforts were made to minimize the stress on smolts during the marking process. Temperature stress was minimized by marking as fast as possible in the morning and in a shady area. The holding, anesthetic and recovery water were changed frequently during the procedure. The holding and recovery buckets were also aerated using battery-operated pumps. Generally, fish sampled for length, weight and/or scale samples are not used for marking as the added stress may affect their migration behavior and thus chance of recapture (Frith et al., 1995). As such where the numbers of available smolts were low (>10 per day or estimated 200 per annum), marking fish was deemed more important than bio-sampling and thus bio-sample sizes may be low or zero. When the marking process was completed, the marked RST origin smolts were transported upstream 500m to Eagle Point (Figure 2 & 6), placed in a holding box, and subsequently released at dusk. Steelhead and chinook smolts were not marked in 2007 due to the low numbers captured. All fish caught at the RST and not marked were enumerated and released 300m downstream of the RST site (Figure 2). Each day’s smolt migration is defined as the fish caught in a 24-hour period (approx. 8am to 8am). Coho smolts were also marked, utilizing a different set of marks (than RST captured fish) at the trap located on Upper Paradise (UP) restoration channel (Site 6; Figure 2 & 6). These fish were available on a daily basis for the majority of the outmigration period as trap operation has not been influenced to the same extent as the RSTs by high flows and thus trap operation has rarely been suspended. As well, fish have been more abundant than those available to mark at the RST site. Smolts captured at the restoration channel trap each day were marked in the morning and held until dusk in a holding box immediately downstream of the trap site. This differed from 2001 to 2004 when fish were released immediately after recovery from marking. The new procedure was implemented in 2005 in an attempt to minimize any predator related mortality on these marked fish (Melville & McCubbing, 2006). Page 12 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   For the purpose of marking and enumeration estimates, coho and steelhead age classes were defined by the following fork lengths: >70 mm for coho smolts, <70mm for coho fry (2007 brood), and >140 mm for steelhead smolts, <140mm but >70mm for steelhead parr, and <70mm for steelhead fry (2007 brood). We also used visual appearance to distinguish smolting from non-smolting fish. Steelhead age was based on the length partitioning of steelhead smolts and parr from juvenile scale samples collected from 2000 to 2003 which were examined by methods described in Ward et al., 1989, and has been previously reported (Melville & McCubbing, 2005; Korman & McCubbing, 2007). Three components of the chinook juvenile outmigration were classified by fork lengths – these being as follows: 0+ (2006 brood year) early spring (February & March) fry, <70mm in length; 0+ (2006 brood year) late spring (April & May) fry, 70-90mm in length; and spring 1+ (2005 brood year) spring smolts, >90mm in length (Table 5). 2.5 Fish Sampling On the majority of days, 25 coho smolts and 20% of steelhead and chinook smolts and steelhead parr (up to 25 individuals) were measured at the RSTs and at the Upper Paradise smolt trap (Site 6; Figure 2). Depending on fish numbers an adaptive protocol was implemented in order to maximize marked fish and to continue to sample a portion of the fish, whereby if fish numbers were less than 25 per day sampling frequency was reduced to every other day and lower numbers of captures resulted in bi-weekly or no sampling. In order to reduce handling stress, fish were anaesthetized with a diluted solution of clove oil, dissolved 1:10 in ethanol. Fork lengths (to the nearest mm) were recorded for each fish sampled; weights were recorded bi-weekly. Scale samples were taken for a small stratified sub sample of steelhead juveniles by the methods detailed in Ward et al., 1989. Chum, chinook, coho and pink fry were sampled bi-weekly for length and weight throughout the sampling period provided sufficient fish were available. InStream Fisheries Research Inc. Page 13 2.6 Data Analysis 2.6.1 Mark Recapture Pooled Peterson population estimates can be calculated from the basic mark recapture equation provided by Ricker (1975): N = (M+1)*(C+1) + (mortalities) (R+1) Where N = population estimate C = total catch R = number of marked fish recaptured M = number of marks released In this study, analysis was carried out utilizing the SPAS computer program (Arnason et al., 1996) which reports the pooled Peterson estimate (PPE) and its standard error using the Chapman hypergeometric model, as described in Seber (1982). The term pooled refers to pooling of mark strata. Actual daily outmigrations have been observed to violate a number of the above assumptions in some cases (Decker, 1998; Schubert et al., 1994). Recapture rates may vary between groups as a result of differential tagging stress, temporal variances in recapture rate through release date and river discharge, and/or residulization and mortality. To overcome bias created by using average trap efficiency through the whole study period, data may be stratified into different marked groups. This stratified data utilizes the different marked groups and their recapture efficiencies as sampled over time to create an estimate. It is not always clear what criteria are best for stratifying the data and subsequent pooling of strata. In this case, temporal groups (of seven days) were used. Strata were then pooled together based on the maximum likelihood Darroch (ML Darroch) estimator developed by Plante (1990). It is an iterative process and uses initial values calculated by least squares methods. These calculated stratum values are compared to the predicted values from the fitted model and a goodness of fit test is used to assess the deviation of the observed from the predicted. Such a method can be applied to remove bias that can occur in complete pooling (Seber, 1982) and allow an independent method of evaluating the likely confidence in individual Peterson year/age class estimates. While individual data are presented for each age class and year, some estimates could not be calculated and thus for comparative purposes we use Peterson estimates at this time. Page 14 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Estimated catch efficiencies of the traps were recorded by marked group and indicate trap efficiency through specific time periods. Variations in observed recapture rates amongst different life stages indicated differential susceptibility of smolts and fry to being recaptured at the RST site. These varied statistically (see Results) within and between species, across the sample period, and between trap locations; and may be related to changes in trap efficiency at varied flows, loss of marks through mortality or predation, and trap avoidance. Examination of this data may allow for improved study design in future years, resulting in improved precision and accuracy of population estimates. Modeling to address these issues are ongoing (Bonner & Shwartz, 2007a & b). 2.6.2 Fish Counter Data Analysis Counter data analysis was under taken for all periods when the counter was operating. The total number of fish enumerated by the counter was assessed from the counter records. Total outmigration for each counting period (day or part thereof) was estimated from the following equation developed from McCubbing, 2003: 1) where Dc Uc Dct is the total down count for each size class of fish each sample day is the total up count for each size class of fish each sample day is the calculated downstream outmigration estimate for each size class of fish during time period t. A series of daily results from the counter can thus be evaluated. By incorporating a calculated efficiency from video validation or a similar verification of counts, a downstream outmigration estimate can be calculated from the equation: 2) Dc = Dct /E *100 + Dct+1 E+1 *100 + …. through time T Dct = Dc – Uc where E Dc is the calculated or substituted counter efficiency is the calculated downstream outmigration count over time T. Upstream migration can be similarly estimated. InStream Fisheries Research Inc. Page 15 3.0 RESULTS 3.1 Trap, Counter and Fyke Net Operations Operations of traps, fyke nets and counters are affected by river discharge and releases of hatchery fish. High discharge may reduce effective trapping or result in trap loss if precautions are not taken (i.e. trap removal) while hatchery releases result in large numbers of co-migrating fish during short periods which may overwhelm trap box capacities. As such, proposed operational times may be reduced or enumeration days missed during these events. In the case of full span traps and counters, this will result in an estimated minimum outmigration based on the total fish captured (or counted) rather than an assessment of total numbers passing the trap location. In the case of mark recapture estimates, the theory is that reduced trap operation times will not affect the potential to derive population estimates. It will however likely result in broader confidence limits around the estimate as a result of lower amounts of marked fish captured than if the trap/fyke net had been fishing (Ricker, 1975). 3.1.1 River discharge and trapping/counter operations Due to low flows, only RST #1 was in operation during the first five days of the study, February 16th to the 21st, after which flows increased slightly and allowed operation of both traps (Table 3). On a further two days, March 25th (high water) and April 29th (trap malfunction), only one trap was operated. There were eight days where no RSTs were operated: March 12th, 13th, 18th, 20th and April 28th due to high discharge, and April 24th, May 4th and 5th in response to hatchery releases of fish (Table 3). In 2007, both RSTs were removed on June 1st – earlier than in previous years of the study (normally removed between June 10-15). The removal was based on predictions from BC Hydro staff of consistent high flows after May 31st due to a high snow pack and warming temperatures. In summary, during the period of February 16th to May 31st, two traps were utilized for 87.5% of the potential 104 trapping days. In spring 2007, Upper Paradise smolt trap was operated from April 2nd to June 8th (Table 1) after which backwatering precluded further operations. No other traps, counters or fyke nets were affected by discharge and were operated until such time as capture of fish approached zero (Table 1). Page 16 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   3.1.2 Hatchery releases and trapping/counting operations A number of lost trapping days were due to hatchery releases from the NVOS hatchery and from the Tenderfoot Creek Hatchery operated by FOC (Table 2). Chum Fry 0+ (2006 brood) NVOS undertook two releases of chum fry, the first on the evening of April 9th totaling 21,274 and the second on May 4th totaling 15,174 fish. Fyke net trapping was suspended at the NVOS complex enumerator fyke trap site (Site F; Figure 2) until the afternoon of April 10th and May 5th, respectively, to allow these fish to pass (Table 3). FOC Tenderfoot Hatchery released 54,838 chum fry to Tenderfoot Creek on April 25th. Operations at the RST site were not suspended for these releases and as such the total number released are subtracted from the production estimate generated for above the RST site. Coho smolts 1+ (2005 brood) FOC Tenderfoot Hatchery undertook two releases of coho smolts on May 3rd, 2007. The first was 129,169 adipose clipped coho smolts (average 19g & 121mm) released volitionally from the Hatchery (FOC, data on file). The second release consisted of 58,530 non-clipped coho smolts released to the Cheakamus River at RK 13 – this is a departure from previous years’ operations and is a response to mitigate coho losses to the upper reaches of the Cheakamus resulting from the 2005 NaOH spill (McCubbing et al., 2006). On the afternoon of the release (May 3rd) both RSTs were brought in and trapping was suspended until the evening of May 5th (Table 3). The majority of these fish were assumed to have passed the traps while operation was suspended May 4th and 5th; unmarked hatchery coho caught after May 5th were easily identified by their appearance and size (average hatchery fish weighed 21g with a fork length of 123mm in comparison to wild coho that averaged 8.4g and 88.4mm in 2007, respectively). Hatchery fish were not sampled or included in production estimates. Chinook 0+ (2006 brood) A release of juvenile chinook occurred on May 1st into Tenderfoot Creek and was similar to previous years. An unknown number of 0+ chinook juveniles (estimated as <1000) were volitionally released from Tenderfoot Creek Hatchery (RK 6.5). These fish are larger than their wild counterparts and were not sampled or evaluated in production estimates. InStream Fisheries Research Inc. Page 17 As a response to mitigate chinook losses during the 2005 NaOH spill a release of 98,947 unmarked chinook juveniles to the mainstem of the Cheakamus at RK 12 to 15 was undertaken by FOC. These fish were released from April 20th to 23rd, and trapping at the RSTs was suspended for one day on the evening of April 23rd to allow these fish to pass (Table 3). The growth of 0+ chinook is accelerated in the hatchery compared to their wild counterparts thus making them easily identifiable by size and appearance. Hatchery chinook averaged 7.1g and 87mm while wild 0+ chinook fry captured after April 15th historically have averaged 3g and 1+ chinook smolts have historically average 10g (data on file). When trapping resumed, captured hatchery chinook were identified based on appearance and were not recorded. These fish were excluded from all production estimates. Steelhead smolts 1+ (2006 brood) A total of 10,679 smolts from Fraser Valley Trout Hatchery averaging 77 grams were released at various locations. A small release of 2,000 fish was undertaken at an upstream site, RK 14.5, and an additional 2,000 fish were released in Sue’s Channel at the NVOS property, both on May 11th. Trapping was suspended at the NVOS complex enumerator fyke trap site (Site F; Figure 2) from the evening of May 11th to 14th to allow the steelhead smolts released in Sue’s channel to bypass the trap (Table 3). The remaining 6,598 fish were released downstream of the Cheekye confluence on May 23rd. A total of 10,826 steelhead smolts with average weight of 66g were released volitionally from Tenderfoot Hatchery on May 6th. All fish were adipose clipped and RST operations were not suspended during or after releases. All hatchery fish were released downstream of the RSTs and were excluded from production estimates. 3.2 Biophysical Monitoring Discharge (measured at WSC 08GA043) at the Cheakamus River near Brackendale during trap operation ranged from an average daily value of 16.1 m3/s to 122.8 m3/s over the period of February 16th to June 2nd (Figure 7). Average daily water temperature at the RST data logger ranged from 2.950C to 9.090C from February 16th to June 2nd (Figure 8). 3.3 Mainstem Chum Fry Migration and Production Page 18 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Chum fry migration was underway as RST operations began on February 16th, with fish captured on the first day of operation. The majority of observed fish were sampled between March 18th and April 21st – a total of 75% of chum fry captures (Figure 9). Proportionally, 10%, 50% and 90% of chum fry captures were made by March 21st, April 7th, and April 30th, respectively. As in previous years, the observed peak of chum fry captures coincided with an increase in water temperature from an average weekly temperature of 3.80 to 5.70C and daytime high water temperatures approaching 70C. Based on diminished captures in previous years, ninety percent of the chum fry were estimated to have migrated prior to the drums being changed to larger mesh on May 18th (Table 2; Melville & McCubbing 2001-2007). While the larger mesh drums did capture some chum fry, insufficient fish were caught for marking and thus efficiencies are unknown. The total number of chum fry caught at the RST site was 395,378, including moralities (Appendix 1-A). This is the highest capture of chum fry since the study began in 2000, the range of which is 54,527 to 354, 337 (Table 4). Eleven mark groups totaling 82,827 fish were re-released upstream. A total of 6,975 of these marked fish were recaptured at the traps, giving an average ECE of 8.4%, and an individual mark group recapture rate that ranged from 4.1% to 14.3% (Appendix 2-A). Based on the combined mark and recapture data (i.e., pooled Peterson estimator) the total chum fry emigration past the trap site was estimated to be 4,635,606 fish with a 95% confidence interval of 4,532,441 and 4,738,769. This is reduced to an estimate of 4,544,320 fry when hatchery fish released from the NVOS and DFO are removed from the estimate. However, the assumption of complete mixing was not met as the percentage of marks recovered differed significantly between release periods (chisquare, df = 10, X2=1265, p <0.001). This indicates that the trap efficiency and/or the migration pattern of fish varied over the sampling period, as can be seen in Appendix 2-A. The assumption of equal proportions of marked versus unmarked fish among recovery strata was also not met (chi-square, df = 10, X2 = 1154, p <0.001). These test results indicate that pooling may create bias in the population estimate. In an attempt to examine the bias, we pooled recovery strata 1 with 2 (low number of marks and captures in strata 1). A ML Darroch estimate of 4,515,933 chum fry with 95% confidence limits of 4,403,821 to 4,628,045 was calculated. The G2 value associated with this estimate (G2 < 138, df =1, p=0.0) indicated a poor fit to the data (Arnason et al., 1996) but other pooling efforts failed to improve on this estimate or confidence limits. An estimated 74,119 chum fry passed the RST site before February 26th and after May 14th. This figure was derived using the delta method: total number of fish in caught divided by the mean efficiency for all release strata (8.4%). Thus a total estimate of yield upstream of the RST site was 4,590,052. If we remove the amount of known hatchery fish total yield is reduced to 4,498,766. InStream Fisheries Research Inc. Page 19 A total of 4,746 chum fry mortalities were incurred between the two traps. This represented approximately 0.1% of the estimated chum fry emigration, or 1.2% of the chum fry caught in the traps (Appendix 1-A). 3.3.1 Chum Fry Length Mean length and weight for chum fry in Spring 2007 was 38mm and 0.4g (Table 6). A statistically significant observed difference in mean fry length was found between the seven sample years, 2000 to 2007 (ANOVA, p=0.001, F=45, df=7). Largest fry were captured in 2001 and 2003, with smallest fish captured in 2004 and 2007 (Table 7). 3.4 Side-channel Chum Fry Migration and Production 3.4.1 Upper Paradise/Gorbushca Complex Chum Migration and Production Chum fry migration was underway when the NVOS complex enumerator fyke trap (Site F; Figure 2 & 3) was deployed on March 17th, thus a complete production estimate and migration timing curve is not possible with 2007 data alone. On the first day of operation 6,276 chum fry were captured. Trapping ended on May 16th when daily capture had diminished to <100 fry per day and migration timing data indicated that the chum migration was near completion (Melville & McCubbing, 2000-2007 & data on file). The total number of chum fry caught at Site F was 221,198 chum fry including moralities (Appendix 1-B). Seven mark groups totaling 11,309 fish were marked and released at the marking fyke traps upstream of Site F on the NVOS complex (Figure 3). A total of 933 of these marked fish were recaptured at the NVOS complex enumerator trap (Site F), giving an average ECE of 8.3% and an individual mark group recapture rate that ranged from 0.4% to 16.1% (Appendix 2-B). Based on the combined mark and recapture data (i.e., pooled Peterson estimator) the total chum fry emigration past the NVOS enumerator trap Site F was estimated to be 1,673,636 fish with a 95% confidence interval of 1,571,231 and 1,776,042. However, the assumption of complete mixing was not met as the percentage of marks recovered differed significantly between release periods (chi-square, df = 6, X2=518, p 0.00). This indicates that the trap efficiency and/or the migration pattern of fish varied over the sampling period, as can be seen in Appendix 2-B. 3.4.2 Kisutch Groundwater Channel Chum Migration and Production As with the NVOS complex enumerator fyke trap site, chum fry migration was underway on March 27th, the first day of operation of the Kisutch enumerator fyke trap (Site D; Figure 2 & 3), thus a complete Page 20 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   production estimate and migration timing curve was not possible with only 2007 data. On the first day of operation 332 chum fry were captured. Trapping ended on May 14th when daily capture had diminished to 0 fry per day and migration timing data indicated that the chum migration was near completion (Melville & McCubbing, 2000-2007 & data on file). The total number of chum fry caught at Kisutch enumerator fyke trap (Site D) was 14,086 chum fry including moralities (Appendix 1-B). Five mark groups totaling 7,549 fish were released upstream at the Kisutch marking fyke trap (Site C; Figure 2 & 3). A total of 211 of these marked fish were recaptured at the enumerator fyke trap, giving an average ECE of 2.8% and an individual mark group recapture rate that ranged from 0% to 5.5% (Appendix 2-C). Based on the combined mark and recapture data (i.e., pooled Peterson estimator) the total chum fry emigration past the Kisutch enumerator fyke trap Site D was estimated to be 501,504 fish with a 95% confidence interval of 435,607 and 567,400. However, the assumption of complete mixing could not be calculated. This indicates that the trap efficiency and/or the migration pattern of fish varied over the sampling period, as can be seen in Appendix 2-C. 3.4.3 Upper Paradise Groundwater Channel Chum Migration and Production Upper Paradise groundwater channel chum fry assessment was partially compromised by the construction of a new river intake channel that now enters the original groundwater portion of Upper Paradise, reducing the groundwater area reach length to less than 500m. This channel was constructed after the Terms of Reference for the Cheakamus Juvenile Monitor 1A were written. As the new river water channel shortened the distance of available groundwater channel to assess, the ability to capture sufficient fish for marking in the upstream marking fyke trap (Site A; Figure 2 & 3) was restricted. Chum fry migration was underway on the Upper Paradise groundwater channel when trap operation commenced on March 30th (Site A & B; Figure 2 & 3), thus a complete production estimate and migration timing curve was not possible based on 2007 data only. On the first day of operation 197 chum fry were captured. Trapping ended on May 11th when daily capture had diminished to <10 fry per day and migration timing data indicated that the chum migration was near completion (Melville & McCubbing, 2000-2007 & data on file). The total number of chum fry caught at the enumerator trap Site B was 9,117 chum fry including moralities (Appendix 1-B). Six mark groups totaling 808 fish captured at marking fyke trap Site A were released upstream of Site B (Figure 2 & 3). A total of 20 of these marked fish were recaptured at the InStream Fisheries Research Inc. Page 21 enumerator fyke net trap (Site B), giving an average ECE of 2.5% and an individual mark group recapture rate that ranged from 0% to 5.4% (Appendix 2-D) Based on the combined mark and recapture data (i.e., pooled Peterson estimator) the total chum fry emigration past the trap site was estimated to be 348,254 fish with a 95% confidence interval of 204,795 and 491,712. This estimate is based on only 20 recaptures in one stratum and as such is likely a poor indicator of total channel yield. 3.5 Pink Fry Migration Nineteen pink fry were captured at the RSTs in 2007. These numbers are low as 2006 is an off-year for adult migration on the Cheakamus River and few spawners were observed. 3.6 Chinook Fry and Smolts 3.6.1 Chinook Fry Migration and Production On February 16th, the first day of trap operations, 146 chinook fry were captured. During the sampling period emigration was characterized by two peaks in catch: between Feb 18 and March 10th, when 34% of the total sample was caught; and April 8th through May 19th, when 43% of the run was captured. The low captures recorded between April 22nd and May 5th is likely a result of four lost fishing days due to hatchery releases and high discharge. Chinook fry were caught in small numbers prior to, and after the peak (Figure 10). This bi-modal migration pattern is similar to most years of the study, 2000-2007 (Melville & McCubbing, 2007). Proportionally, 10%, 50% and 90% of chinook fry captures were observed on February 23rd, April 7th and May 14th, respectively. It does not appear that increased temperature or flow affected the migration timing of chinook fry (Figure 10). The total number of chinook fry caught in both traps was 8,742 including mortalities (Appendix 1-A). This is the highest catch since the study commenced in 2000 with the lowest previous catch occurring in 2006, the range of which was 499 to 8,558 (Table 4). Eleven mark groups totaling 2,853 fish were rereleased upstream. A total of 146 of these marked fish were recaptured at the traps, giving an average ECE of 5.1% and an individual mark group recapture rate that ranged from 0% to 7.1% (Appendix 2-E). Based on the combined mark and recapture data (i.e., pooled Peterson estimator) the total chinook fry emigration past the trap site was estimated to be 126,002 fish with a 95% confidence interval of 106,456 and 145,547. However, the assumption of complete mixing was not met as the percentage of marks recovered differed significantly between release periods (chi-square, df = 10, X2=20.59, p 0.02). This indicates that the trap efficiency and/or the migration pattern of fish varied over the sampling period, as Page 22 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   can be seen in Appendix 2-E. The assumption of equal proportions of marked versus unmarked fish among recovery strata was also not met (chi-square, df = 10, X2 = 56.42, p 0.00). These test results indicate that pooling may create bias in the population estimate. In an attempt to examine the bias, we pooled recovery strata 4 with 5 (no recaptures in strata 4) and marking strata 5 with 6 and 9 with 10 (low number of marks applied). A ML Darroch estimate of 194,327 chinook fry with 95% confidence limits of 78,457 to 310,198 was calculated. The G2 value associated with this estimate (G2 < 0.02, df =1, p=0.89) indicated a good fit to the data (Arnason et al., 1996). An estimated 24,327 chinook fry passed the RST site before February 26th. This figure was derived using the delta method: total number of fish in caught divided by the mean efficiency for all release strata (5.1%). Thus a total estimate of yield upstream of the RST site was 218,700 by ML Darroch or 150,374 by pooled Peterson estimate (Appendix 1-A). A total of 169 chinook fry mortalities were incurred at the traps. This represented approximately 0.1% of the estimated chinook fry emigration, or 1.9% of the chinook fry caught in the traps (Appendix 1-A). 3.6.2 Chinook Smolt Migration and Production A total of 47 chinook smolts (1+) were captured, with no mortalities (Appendix 1-A). Insufficient smolts were available for marking, thus no mark recapture estimate nor runtime analysis were possible in 2007. Peak capture of chinook smolts occurred between April 15th and May 13th when 72% of the samples were enumerated (data on file). 3.6.3 Chinook Length and Age Data Mean length and weight for early chinook fry in spring 2007 was 38mm and 0.6g (Table 6). There was a statistically significant observed difference in mean length of chinook fry between the seven sample years 2000 to 2007 (ANOVA, p<0.001, F=186, df=7). Fry were generally smaller in 2004 and 2007 (Table 7). Mean length and weight for chinook smolts caught at the RST in the spring of 2007 was 103mm and 14.7g (Table 6). There was a statistically significant observed difference in mean length of chinook smolts between the sample years 2000, 2002/3 and 2007 (ANOVA, p<0.001, F=4.17, df=4). Sample sizes are however low in all years except 2000 (Table 7). Length frequency for all chinook juveniles was bi-modal with the first mode in the 30 to 49mm range, representing 0+ fry (Figure 11), and a much less frequent second mode (90-125mm), representing 1+ smolts. This is similar to six of the seven sample years, 2000 to 2006 (Melville & McCubbing, 2007). InStream Fisheries Research Inc. Page 23 3.7 Steelhead Parr and Smolts 3.7.1 Mainstem (RST) Steelhead Smolt Migration and Production In 2007, a total of 20 steelhead smolts (2004 & 2005 brood years; Table 5) were captured, with no mortalities (Appendix 1-A). This is among the four lowest annual catches of steelhead smolts since 2000, all of which have occurred since 2004. The range of steelhead smolts numbers captured since 2000 is 5 to 429 (Table 4). Fifty-five percent of the observed captures (11 fish) occurred between April 22nd and May 19th (Figure 12). Insufficient smolts were available for marking, thus no yield estimate was possible in 2007. 3.7.2 Mainstem (RST) Steelhead Parr Migration and Production In total 621 steelhead parr (2006 brood year; Table 5) were captured at the RSTs, with no mortalities (Appendix 1-A). This is the highest annual capture to date since the study started in 2000, the previous range being 6 to 256 fish (Table 4). The peak of steelhead parr captures occurred between May 6th and the suspension of trap operations on May 31st, when 84% of steelhead parr were captured (Figure 13). Steelhead parr were not marked and population estimates were not attempted. 3.7.3 Side Channel Steelhead Migration and Production Thirty steelhead smolts and 371 steelhead parr were captured at the Upper Paradise trap in 2007 (Site 6; Figure 2, Table 4). 3.7.4 Steelhead Lengths and Weights Mean steelhead smolt length and weight in spring 2007 was 163mm and 47.4g; while steelhead parr mean length and weight was 92mm and 9.6g (Table 6). Due to low capture and sample rates in 2004 through 2007, data was insufficient to make comparisons of size between years. Length frequency for all steelhead juveniles (parr and smolts) was bi-modal in 2007, likely representing 1+ parr (non-migratory) in the 60 to 140mm range and 2 and 3+ smolts in the 140 to 200mm range (Figure 14, Table 5). Due to the low numbers of 2 and 3+ smolts the second mode is not easily defined in 2007. No scale samples of fish >140mm were collected in 2007 due to low capture numbers. 3.8 Mainstem Coho Smolt and Fry Migration & Production 3.8.1 Coho Smolts Coho smolt captures peaked between April 29th and May 26th when 77% of the total sample was caught. The last coho smolt was captured on May 31st when trapping was suspended due to high flows (Figure 15). Page 24 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   The RSTs were not fished as discussed in Section 3.1.2, following the Tenderfoot Hatchery release of 129,169 adipose clipped and 58,530 non-clipped fish on May 3rd. The hatchery release appeared to be just prior to the peak of coho smolt migration on the Cheakamus (Figure 15). Proportionally, 10%, 50% and 90% of coho smolt captures occurred on April 19th, May 15th, and May 26th, respectively. Coho smolts followed the pattern observed in all years since the study commenced in 2000 on the Cheakamus River, beginning their peak emigration period when average daily water temperatures reached 70C (Figure 15). Coho juvenile migration on the Cheakamus River is primarily made up of 1+ smolts (2005 brood year; Table 5), based on previous years’ length frequency data (Melville & McCubbing, 2001 through 2006). In 2007, as in other years, a small component of emigrants (258 or 3.4%), were classified as (1+) coho parr. These fish were caught primarily in February and March and had not yet achieved the size (>70mm) and appearance of smolts. A final component of coho juvenile monitoring in 2007 was the presence of 0+ coho fry, totaling 10,691 fish. These fish have been captured in varying numbers in all years of the study although 2007 catch is by far the highest to date (Table 4). Coho fry migration commenced with newly emerged fry and increased as flows increased during the sample period and dropped to zero when the drums were changed to large mesh on May 18th (Figure 16). 3.8.2 RST Marked Coho In total 7,235 coho smolts were captured in the two RST traps (Appendix 1-A). This catch falls within the range of the three highest catches to date, observed as 7,235 to 11,177 smolts (Table 4). Seven mark groups totaling 6,031 fish were re-released upstream at dusk. A total of 625 of these marked fish were recaptured at the traps, giving an average ECE of 10.4% and an individual mark group recapture rate that ranged from 3.2% to 13.9% (Appendix 2-F). The average ECE is higher than the last three years’ (4.0% in 2004, 5.8% in 2005 and 6.5% in 2006), but within the range of the early operations (2000-2003) when efficiencies of 8.1% to 20.5% were calculated (Table 4). InStream Fisheries Research Inc. Page 25 Based on the combined mark and recapture data (i.e., pooled Peterson estimator), the total coho smolt emigration past the trap site was estimated to be 80,737 fish with 95% confidence interval of 74,982 to 86,492 (Appendix 1-A). The assumption of complete mixing could not be calculated as the percentage of marks differed significantly between release periods (chi-square, df = 6, X2=63, p = 0.00). The assumption of equal proportions of marked versus unmarked fish was not met (chi-square, df = 6, X2 = 70.89, p=0.00) due to high variance between stratum and stratum with no recaptures. The later result may indicate the PPE was biased (Arnason et al., 1996). In an attempt to examine any bias, we pooled marking strata 1 with 2 (low numbers of marks applied in strata 1). A ML Darroch estimate of 96,990 coho smolts with 95% confidence limits of 82,781 to 111,119 was calculated. The low G2 value associated with this estimate (G2 < 0.00, df =1, p=0.97) indicates a good fit to the data (Arnason et al., 1996). An estimated 1,580 coho smolts passed the RST site before the April 1st. This estimate was derived using the delta method: total number of fish in captured prior to April 1st divided by the mean efficiency for all release strata (10%). Total estimate of coho smolt yield upstream of the RST site was 98,570 (Appendix 1-A). 3.8.3 Side-Channel Marked Coho In addition to marking and re-releasing groups of coho smolts upstream of the RSTs, coho smolts were marked at the Upper Paradise smolt trap (Site 6; Figure 2). Seven mark groups totaling 7,422 fish were released at dusk of the day marked at the Upper Paradise trap site. Recapture rates ranged from 3.9% to 11.2%. A total of 676 of the side-channel marked fish were recaptured at the RST location, giving an average ECE of 9.1% (Appendix 2-G). The 2007 average ECE is one of the two highest ECEs derived from side-channel marked fish, the other being 9.3% in 2001 (Table 4). Using ECEs from side-channel marked smolts, the combined mark and recapture data (i.e., pooled Peterson estimator) of total coho smolt emigration past the RST site was estimated to be 85,018 coho smolts with 95% confidence limits of 79,189 to 90,846 (Appendix 1-A). The G2 value associated with this estimate (G2 = 53, df =6, p=0.00) indicates a poor fit to the data (Arnason et al., 1996). The assumption of equal proportions of marked versus unmarked fish among recovery strata could not be calculated (chisquare, df = 6, X2 = 181, p=0.00) due to high variance between stratum and several strata without recaptures. The later result may indicate the PPE was biased (Arnason et al., 1996). Page 26 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   In an attempt to examine any bias, we pooled recovery strata 1 through 3 (low recaptures) and marking stratum 1 and 2 (low numbers of fish marked). A ML Darroch estimate of 102,107 coho smolts with 95% confidence limits of 89,396 to 114,891 was calculated. The low G2 value associated with this estimate (G2 = 2.96, df =1, p=0.09) indicates a reasonable fit to the data (Arnason et al., 1996). An estimated 1,580 coho smolts passed the RST site before the April 1st. This estimate was derived using the delta method: total number of fish in captured prior to April 1st divided by the mean efficiency for all release strata (10%). Total estimate of coho smolt yield upstream of the RST site was 103,687 (Appendix 1-A). 3.8.4 Coho Lengths Mean length and weight of coho smolts caught in spring 2007 at the RST site was 88.4mm and 8.5g. Mean length and weight sampled at Upper Paradise channel (Site 6) was 91mm and 8.5g (Table 6). There was a statistical difference between lengths of smolts captured at the RST (potentially mainstem and/or off-channel rearing, excluding Upper Paradise channel) compared with those sampled in the trap at Upper Paradise channel. Side-channel reared smolts were significantly larger than main river captured counterparts (T-test un-equal variance, t=3.3, p = 0.001). There was also a statistically significant difference in the mean length of coho smolts sampled at the RSTs between the six sample years 2000 to 2007 (ANOVA p<0.001, F=20.3 df=7). Mean smolt length sampled at the RST site was lowest in 2007 and highest in 2006 (Table 7). The length frequency of all coho juveniles captured at the RSTs and Upper Paradise side-channel in 2007 was normally distributed with smolts peaking between 85mm and 104mm range, and fry between 35mm and 44mm (Figure 17). Scales were not taken in 2007. 3.9 Side Channel Coho Smolt Yield 3.9.1 Kisutch Channel Fish Counter Kisutch channel counter was operational from April 8th at 3pm through June 8th when counts had reduced to close to zero. During this time a number of brief power outages were recorded on April 25th and 26th and May 6th as the power demands of the system and battery change routines were developed. A total of 2,347 events were recorded by the fish counter during this period, of which 132 were classified as up counts and 205 as down counts. Some periods of noise were observed due to debris collection on the diversion screens which resulted in air entrainment through the counting tubes. This is typically exhibited as repeated small events recorded every few seconds on one or more counting tubes. These events were InStream Fisheries Research Inc. Page 27 generally observed during daylight hours or early in the morning, and were excluded from analysis as smolts were not visually observed migrating during the day. Evaluation of peak signal size data indicated the majority of events were <80 in size (98.8%) with just 26 events of PSS >80, (Figure 18). The larger fish are likely to be resident or migratory trout as previously sampled in Upper Paradise trap (Site 6; data on file). Timing of smaller counter records indicated a large amount of data was collected in the dusk to dawn period between May 13th and June 3rd (Figure 19). The majority of these records were classified as events (86%) but were likely generated by misclassified coho smolt emigrants because the peak signal size generated on one half of the input signal was close to threshold. Limited video footage failed to provide information on fish movement despite over 4 hours of data analysis at prime times (dusk and during early night hours). Unfortunately in spring 2007 the video cameras and recorder were not operational at this location during periods of fish movement and as such no fish were observed to corroborate our assessment. However, footage confirmed that over the period filmed and evaluated when there were no counter records, no fish were observed. In 2007, a preliminary estimate of yield was calculated assuming that all counter records of PSS<80 which were not assessed as noise were generated by coho emigrants and that all such events were down migrants. Summing events and down counts minus up counts and without correction for counter efficiency, we estimate 2,122 out-migrant coho smolts passed downstream through the Kisutch counter site in the spring of 2007 (Table 8). This very preliminary data analysis requires confirmation by additional data collection in 2008. 3.9.2 BC Rail Channel Fish Counter BC Rail channel counter was operational from April 4th at 3pm through June 4th when counts approached zero. During this time a number of brief power outages were recorded on April 9th and 25th as the power demands of the system and battery change routines were developed. A total of 1,627 events were recorded by the fish counter, of which 238 were classified as up counts and 276 as down counts. Periods of noise were observed due to debris collection on the diversion screens resulting in air entrainment through the counting tubes. These events were generally observed during daylight hours or early in the morning and, as at Kisutch channel, were recognized by the pattern of record timing and frequency. Evaluation of peak signal size data indicated the majority of events were <80 in size (83%) with just 207 events of PSS >80. A bi-modal migration timing was observed for smaller targets with a mode in late April/early May and a second in late May/early June (Figure 20). The majority of these records were Page 28 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   classified as events (53%) or down counts (11%) and likely all relate to coho smolt emigration, based on size/run timing and data collected at other locations/traps. Reasons for misclassification will likely be as with Kisutch counter. In 2007, a preliminary estimate of yield was calculated assuming that all counter records of PSS<80 which were not assessed as noise were generated by coho emigrants and that all such events were down migrants. Summing events and down counts minus up counts and without correction for counter efficiency, we estimate 1,064 outmigrant coho smolts passed downstream through the BC Rail site in the spring of 2007 (Table 8). Similar to Kisutch channel counter, this very preliminary analysis requires confirmation by additional data collection in 2008. All but three of the larger events (PSS>80) recorded at BC Rail channel were recorded after May 6th, just after over 10,000 steelhead smolts were released on the adjacent Tenderfoot Creek. Unlike for smaller signal sizes, these larger counter records were dominated by up counts (43%) which, although unconfirmed by video data at this site (Figure 21), are of a signal size likely to be consistent with those generated by steelhead smolts. 3.9.3 Tenderfoot Creek Fish Counter A number of problems were encountered with the operation of the Tenderfoot Creek smolt counter in this first year of study, therefore no defensible yield of smolts could be calculated for this location. The Logie 2100C counter suffered from a buffer memory loss problem on two occasions due to a faulty battery on the central processing card (CPU). Unfortunately this resulted in the loss of counter data during attempts to collect video footage of migrants for counter validation. In addition, the diversion fence design for the site suffered from debris issues which resulted in some periods of open passage for fish. Also, as expected, the diversion fence required removal on several occasions to facilitate migration of large hatchery releases of both coho and steelhead smolts. During periods of normal operation between May 11th and May 24th the counter enumerated 1,701 fish records of PSS <80, of which 1,118 were down counts and 7 were up counts. It also enumerated fish of PSS >80 of which 278 were down counts and 11 up counts. These larger fish were enumerated after the release of steelhead into the creek upstream of the counter on May 6th and were likely late migrants from this release. Many additional event records which may have been generated by fish movement were recorded but are not included in our analysis at this time. We estimate a minimal outmigration of 1,118 smolts of coho size, although wild or hatchery origin cannot be verified and counter efficiency is as yet undefined. InStream Fisheries Research Inc. Page 29 3.9.4 Upper Paradise Channel Smolt Trap The Upper Paradise full span trap (Site 6) was operated similiarly to previous years (2000 through 2006) from April 2nd to June 3rd. During this time 9,519 coho smolts were captured (Table 4). Peak capture was between May 13th and May 19th (data on file). 3.9.5 Upper Paradise Groundwater Channel Smolt Trap The new Upper Paradise groundwater area smolt trap (Site 2; Figure 2) was operated from April 9th to June 2nd. A total of 43 coho smolts were captured during this time (Table 8). Thirty of the 43 fish captured were caught between April 9th and 11th (data on file). Page 30 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   4.0 DISCUSSION 4.1 Fish Trap Operations Rotary Screw Trap operation in 2007 was characterized by stable flows during February 16th to May 31st except for five days when brief freshets precluded trap operations. After May 31st, due to an elevated snow pack and warmer weather, river discharge increased to over 200cms. The observed increase in discharge at this time and continued forecast of warm weather indicated a low likelihood of the river dropping back to a fishable level. Thus, trap operation ceased for the season due to safety and trap removal concerns. Although river discharge reduced to a fishable level after June 13th, had trap operations continued, only two days of extra data would have been collected. As no fish would have been marked for over seven days, little additional information would have been collected in this time period. Improvements to RST design by using increased drum mesh size post May 15th, after fry numbers had declined (Table 2), visually appeared to improve trap operations in higher flows by reducing drag on the cableways. This likely improved capture efficiencies of smolts by increasing the velocity of water passing through the trap and subsequently drum rotation speeds – this requires verification in future sample years. Fish counters were operated from early April through early June on three side-channels until fish migration declined to zero (June 4-6th). Counts were nearly continuous except for brief periods of power outage and at Tenderfoot Creek where data was lost due to a faulty memory card. Fyke traps were operated to assess fry production between March 17th and May 16th (Table 1) at a number of restoration channel locations. Operations likely proceeded after a significant but unknown portion of fry had emigrated, based on fry captures at the RST and initial catches in the Fyke traps in the first sample week. Late implementation of fyke traps in 2007 (February 15th target) was a function of the timing of notification of project start up and subsequent lead time required for net fabrication. 4.2 Juvenile Outmigration Yield 4.2.1 Data Analysis Statistical analysis of mark recapture outmigration data was undertaken on data collected in 2007. Pooled Peterson estimates were calculated for the majority of species/age class cohorts; however, in some cases, statistical analysis indicated that there may be bias in the resultant estimates. To examine the potential bias incorporated in these estimates we also calculated ML Darroch values but, as in previous years, InStream Fisheries Research Inc. Page 31 several data sets were insufficient to provide a comparative estimate. Given these restrictions on analysis, in this report as in previous years we use pooled Peterson estimates for inter-annual comparison of juvenile salmonid yield, accepting that in some years the estimate may yet contain bias due to data capture limitations (i.e. low and varied trap efficiency). We continue to develop alternate methods for evaluating the large data archive (Bonner & Shwartz, 2007a & b) produced since the start of this project and will report these under a separate summary report, on completion. 4.2.2 Chum Fry Migration Mainstem Chum Fry Production The pooled Petersen estimate and 95% confidence limits calculated for chum fry at the RSTs has varied over the eight study years from a high of 4.6 million this year to a low of 1.5 million in 2001 (Figure 22, Table 4). In 2007, average recapture rates (8.4%) for chum fry were similar to 2001 (8.2%) and 2005/2006 (7.1%/8.5%). They were substantially higher than recorded in 2002 and 2004 (4.6% and 4.4%, respectively) and 2000 and 2003 (1.3% and 1.6%, respectively). Changes from day marking to evening/night marking undertaken in 2001 may be responsible for higher ECEs in 2001, 2002, and 2004 through 2007, but do not explain the low trap efficiency in 2003. In 2003, fewer fish were caught and marked (12,239) – a result of varied flow conditions on a week to week basis which limited consistent operation of the traps both for chum fry marking and recapture (Table 4). Availability of fish to mark appears to be the largest factor in determining a precise estimate of fry yield. As this is a function of trap efficiency, years of low fish abundance will thus tend to create less precise estimates. Run timing of chum fry in 2007 appeared to be similar to previous years of observations. In 2000 through 2002, migration likely started before RST operations commenced on March 1st. In 2007, as in other years of trap operation (2003-2006), peak fry captures occurred between the first and third weeks of April with outmigration assessed largely (>95%) as completed by the first week of May (Melville & McCubbing, 2001, 2002a & b, 2003, 2004, 2005 & 2006). Emigration in most years (2000-2005) of operation appears related to average weekly water temperature approaching 70 C, although in 2007 as in 2006 peak captures occurred when average weekly temperatures were slightly lower (4-70C). Page 32 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Side Channel Chum Fry Production As part of increased monitoring efforts derived for the WUP, chum fry production from several channels was assessed in the spring of 2007 for the first time. These locations represented groundwater only channels (Upper Paradise, Site B; Kisutch, Site C) as well as the entire NVOS complex (Site F) which includes flow-through and groundwater channels. Total fry production in the groundwater channels was estimated at 348,254 fish in the groundwater section of Upper Paradise and 501,504 fry from Kisutch. Due to the connection of a new flow-through channel (Sue’s channel, 2006) some 500m downstream of the blind end of the Upper Paradise channel, the effective area of groundwater only influenced habitat in this location has been much reduced. This work was completed in the channel after both the study was designed (2004) and earlier groundwater flow measurements were undertaken (2002). As a result of channel changes, the number of fish available for marking was low and the estimate for Upper Paradise groundwater section is potentially unreliable as it is calculated from just 20 recaptured fry in one stratum. To improve future evaluation of fry production from the reduced sample area, we propose for 2008 to mark fry at the lower enumeration trap, which had captured sufficient fish for this purpose in the spring of 2007. These fish will then be re-released upstream of the enumerator trap at the head of the channel. The total chum fry production from the NVOS complex in 2007 was estimated at 1,673,636 fish, which does not include an unknown number that migrated prior to the start of trapping. Of this we estimate 29% originated from groundwater sources. The total complex production of 1,673,636 fish represents approximately 36% of the total chum fry production estimated at the RST site and highlights the significant contribution of these and likely other natural (i.e. Tenderfoot) and restoration (i.e. BC Rail) channels to chum salmon productivity in the Cheakamus River above the RST site at RK 5.5. 4.2.3 Chinook Juvenile Migration Chinook juvenile migration on the Cheakamus River appears to be made up of four migrant components: spring 0+ chinook fry (early), spring 0+ chinook fry (late), spring 1+chinook smolts, and fall 0+ smolts (Melville & McCubbing, 2001 & 2002; Table 5). Spring 0+ early and late chinook fry accounted for 98% of the total estimated spring migration of chinook juveniles in all sample years (2000 to 2007). An estimate of 150,374 0+ emigrant chinook fry was generated in 2007. The pooled Petersen estimate (PPE) and 95% confidence limits for chinook fry has varied over the five years that estimates were obtained. The PPE for chinook fry has ranged from a high of 212,796 in 2003 to a low of 44,426 in 2004. InStream Fisheries Research Inc. Page 33 The widest confidence limits on estimates have been observed in the sample years where the estimate was derived from small numbers of fish that were available to mark and recapture (300 and 329 marked in 2004 and 2005, respectively; Figure 23). This year’s estimate is based on the highest capture of chinook fry in the eight sample years although only the third highest average ECE (Table 4). No estimate of chinook smolt emigration was generated in 2007. This was due to a low number (47) of captured smolts available for marking and was similar to observations in 2004 through 2006. In comparison, the pooled Petersen estimate for chinook smolts has varied from a high of 2,984 smolts in 2001 to a low of 1,189 in 2003 in the four years for which an estimate has been calculated (2000-2003; Table 4, Figure 24). However, the relatively low number of chinook parr captured and marked each year (81 to 348 fish) has resulted in wide confidence limits around each of these estimates. Each year since 2004, very low captures of chinook smolts have been recorded and no estimate of emigration has been possible. This situation may result from low trap efficiencies or low numbers of emigrants. As trap efficiencies for coho smolts typically trend with chinook capture efficiencies in this study (data on file) and as trap efficiencies in 2007 for coho were high, it appears most likely the lack of chinook captures in 2007 is related to reduced river productivity and not reduced trap efficiency. As lower river production was predicted for chinook originating from the 2005 brood year due to adult losses following the 2005 fish kill, McCubbing et al., 2006, these results are not unexpected. Migration timing observed for 0+ chinook fry in 2007 indicated a prolonged emigration, unlike in 2006 when most fish emigrated after April 15th or in all other years (2000-2005) when the main peak of migration occurred prior to this date. Unlike previous years where a single peak of migration was identified, as occurred in 2002 and 2003, or where a bi-modal outmigration was observed, as in 2000, 2001, 2004 and 2005, in 2007 three modes of increased migration were observed. The last peak of migration was observed late in the sample period, post May 5th. Reasons for the observance of this later migration may relate to improved capture of slightly larger chinook fry following RST drum mesh replacement, although this cannot be corroborated at this time. It continues to be difficult to obtain consistent and precise estimates of all cohorts of chinook juvenile outmigration (Melville & McCubbing, 2006). Given not only the challenges in obtaining juvenile and adult population estimates but also the diversity in life history, the un-quantified effects of varied hatchery releases, and, more recently, the potential effects of the 2005 chemical spill (McCubbing et al., 2006) on future cohort strengths, chinook salmon may be a poor choice for utilization in monitoring the effects of flow regulation. However, continued collection of abundance data and development of production Page 34 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   estimates where possible are warranted if only for evaluation of trend data, given that fish are captured incidentally during trapping operations. 4.2.4 Steelhead Juvenile Migration Spring steelhead juvenile migration on the Cheakamus River consists of two components: steelhead smolts and steelhead parr. No young of the year steelhead fry were captured in the spring as fry emergence occurs in July, after the end of the trap operations (Melville pers. obs., data on file). The pooled Petersen estimate for steelhead smolts has been less than 5,000 smolts in each of the four sample years where an estimate was possible (2000-2003). Estimates of smolt yield have ranged from a low of 2,467 in 2001 to a high of 4,583 in 2003 (Figure 25, Table 4). Compared to more abundant species (chum, coho) the relatively low numbers of fish captured and marked over the four years where an estimate was derived have resulted in low precision of generated estimates (Figure 25). No population estimate was calculated for steelhead smolts in this study year, as in 2004 through 2006. The inability to derive estimates for steelhead smolts since 2004 is specifically due to the low numbers of fish captured and thus available for marking (20 fish in this study year). As with chinook smolts, it is difficult to determine the reasons for this observation and it results in a lack of recaptures that are required to estimate trap efficiency and outmigrant yield. However, there are several potential factors that may have contributed to this situation, and we explore these below: 1) Reduced capture efficiency: Capture efficiency may have been very low at all times during the outmigration in 2007 resulting in the observed low capture totals. If this theory is true, it unfortunately precludes the ability to collect fish for marking to establish its validity. To overcome this circular argument, coho smolts could be used as a surrogate indicator of likely trap efficiency to examine this hypothesis and in this case the theory appears likely false. Capture efficiency of coho and steelhead smolts derived historically (pre 2004) tended to correlate well albeit that they were lower for steelhead than for coho (Table 4). Therefore it seems unlikely that while smolt capture efficiencies derived in 2007 for coho smolts were average (9%) and improved over 2005 and 2006 data (circa 2-3%), that steelhead efficiencies would trend lower. As such low trap efficiency is not the most likely cause of observed low numbers of steelhead smolt captures. InStream Fisheries Research Inc. Page 35 2) Low smolt abundance: As with chinook juveniles, we propose an alternate theory to explain the reasons for low captures of steelhead juveniles in 2006 and 2007. This theory proposes that the effects of mortality resulting from the fish kill in the summer of 2005 (McCubbing et al., 2006) will likely have resulted in the observed low steelhead smolt abundance in both years. The mortality caused by the spill event would have had the greatest impact on 2005 young of the year,migrating as 2-year smolts in 2007 and 3-year in 2008; and on 2004 brood, 1-year old parr, migrating as 2-year smolts in 2006 and 3-year smolts in 2007 (Table 5). Mortality of these cohorts was previously estimated as >90% (McCubbing et al., 2006). Based on these data, significant reductions to these cohorts would be expected in the steelhead juvenile outmigration observed in the spring of 2006 and 2007 and may explain the low smolt capture abundance observed in these sample years. 3) Redistribution of fish: Other lines of evidence, such as the high adult steelhead escapement observed in 2007 (Korman & McCubbing, 2007) challenge the assumption that in all years without sufficient fish to form an estimate (2004 – 2007) steelhead smolt yield from the Cheakamus River was extremely low. The relatively high return of adults documented in 2007 (circa 500) would be largely composed of fish that migrated to the ocean in the spring of 2004 and 2005. Smolt estimates in these years were not calculated due to low capture abundance. If low smolt captures in the RSTs were related to low smolt yield (i.e. <1000 smolts) then either significant straying of adults from other watersheds and/or very high marine survival rates (>1525%) would need to have occurred. As neither is particularly likely, it may be considered that the 1 in 100 year flood which occurred in the fall of 2003 could have redistributed steelhead juveniles (YOY through 2+ parr) from the upper river (above the RST site) to areas downstream of this monitoring location and these fish survived to provide the robust adult steelhead return observed in 2007. The inability to consistently develop robust estimates of steelhead smolts at the RST site which could be directly compared to adult estimates restricts the utility of this data in assessing the affects of varied flow regimes. To augment these data a monitor assessing YOY recruitment and abundance of 1+ and 2+ parr was initiated in 2007 (Cheakamus Water Use Plan: Monitoring Program Terms of Reference, Monitor #4, Feb. 2007). This study in addition to data collected in the existing juvenile and adult programs will improve the understanding of freshwater production and the status of steelhead juveniles in the Cheakamus River in future years. It should also provide important information on the effects of events such as the new flow regime, the 2003 flood, and the 2005 fish kill, on juvenile steelhead production and abundance. Page 36 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Steelhead parr captures at the RST site are classified as incidental as these fish are unlikely to migrate to the ocean (or survive if they do, Ward et al., 1989) and may just be relocating within the watershed. In 2007, 621 steelhead parr were captured. This is a two-fold increase over the highest numbers previously recorded (256 in 2003; Table 4) and indicates a very strong cohort originating from the 2006 brood year. While these data are likely to be a trend indicator of parr abundance, there has been no clear relationship derived between RST parr captures and smolt PPE in subsequent years (Table 4). 4.2.5 Mainstem Coho Smolt Production The pooled Petersen estimate for coho smolts captured and marked at the RSTs has varied over the seven study years from a high of 80,737 this year to a low of 21,602 in 2006 (Table 4). The 95% confidence limits for each of the eight years has been fairly consistent, with the most precise estimate reported in 2000 (Figure 26). Coincidentally the highest number of fish caught and marked and the highest ECE occurred in 2000 (Table 4). Some indication of density dependant growth may have been observed in 2007 as, in general, fish were smaller than in previous sample years (Table 7). A similar growth response was observed at the Keogh River in a high yield year (McCubbing & Ward, 2004). The pooled Petersen estimate for coho smolts estimated from smolts captured and marked at the sidechannels has also varied over the seven study years where this procedure was undertaken. PPEs have ranged from a high of 127,974 in 2003 to a low of 36,209 in 2006 (Table 4). The 95% confidence limits for each of the seven years has been consistent, with the narrowest confidence limits occurring in 2001 (Figure 27). The highest number of fish caught and marked and the highest ECE occurred in 2001. Average ECEs derived from coho marked at the side-channels have been consistently lower than those marked at the RSTs (Table 4) except in this study year. Unlike the past six years (2001-2006), the PPE in 2007 derived from side-channel marked coho was within the upper confidence limit for the PPE derived from mainstem marked smolts re-released upstream. This is a departure from previous years where the difference between estimates has been reasonably large (Figure 28). In 2001, the mainstem estimate was 41% lower than the side-channel derived estimate and similar to the 42% difference observed in 2006. In 2002 and 2003 the estimate was 48% lower, while in 2004 comparative yields were estimated 51% lower based on mainstem marking data. In contrast, estimates derived in 2005 indicated a reduced difference of only 26% between methodologies – a factor initially attributed to reduced predation of marked fish following a switch to dusk releases for sidechannel marked smolts. Reasons for these observations relate to different capture efficiencies between mainstem and side-channel marked fish at the RST. Indirect studies that may yet allow some theoretical InStream Fisheries Research Inc. Page 37 evaluation of the reasons for these variances: loss of marks via predation (Ladell et al., 2007) and/or differential migration patterns (Melnychuck, pers. comm.) are being conducted. In any case, as in the majority of years except 2005 and 2007, the two PPE values trend together, so either estimate is likely a good indicator of relative health of coho smolt production on an inter-annual basis. In the other two years, the estimates tend to corroborate each other and thus the observed variance is not of great concern. The observed migration timing and pattern of coho smolts in 2007 in the Cheakamus River was characterized by a single peak of migration occurring between the first and the third weeks of May, as observed in previous years. This is similar to the migration pattern and timing that has been observed on the Keogh River (Ward & McCubbing, 1998; McCubbing, 1998 – 2000; and McCubbing & Ward, 2002 & 2003.), Waukwaas River (Frith et al., 1995; Melville, 1996 & 1997), and Alouette River (Cope, 1999). Migration of coho smolts is likely temperature and photoperiod driven, which may explain the similar run timing on geographically isolated systems. 4.2.6 Restoration Channel Coho Smolt Production Three automated fish counters were operated for the first time in 2007 to count outmigrant smolts from Kisutch channel, BC Rail channel and Tenderfoot Creek. This method was used in an effort to minimize fish handling stress and the manpower required to trap and count fish. The use of sensor units in these locations was new, and the operations novel as they had not previously been used with small fish (<150mm). The majority of count records recorded at all three locations were events rather than up or down counts (>90%). Some periods of noise were recorded with events generated every few seconds on one or more counting tube. These were linked to air entrainment due to screen blockage and typically occurred in the early morning or late afternoon between cleaning (data on file). Remaining records were typically diurnal in pattern with a seasonal timing consistent with fish movement at other locations. This indicates that the majority may have been generated by fish, but as the PSS was close to the preset threshold value of 20 it is likely that most would be misclassified as events (see McCubbing and Andrusak, 2006, for more detailed explanation). Video validation, which would have verified this assumption, was attempted at two locations; however, for technical reasons footage collected was limited and provided insufficient data for counter efficiency Page 38 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   calculations. Several hours of footage collected at Kisutch channel indicated that during periods when the counter created no records, no fish were observed. No counter records (event, up or down) were available for comparative analysis to video footage. Footage collected at Tenderfoot Creek indicated the visual passage of both wild coho and steelhead (hatchery) smolts, but due to a buffer memory power supply problem on the fish counter, counter data could not be linked to video records. Assuming all events were outmigrant coho and without correction for counter efficiency, we assess the counter at BC Rail fish channel enumerated 1,064 outmigrant coho smolts over the period of counting. This compares with a catch of 5,738 coho smolts during trapping operations in 2001. Using the same assumptions, the Kisutch channel counter estimate for outmigrant smolts was 2,112 smolts, compared to a catch of 2,688 in 2001 trapping operations. Larger fish were also enumerated moving up and down through the tubes and were likely trout juveniles of wild and hatchery origin. Tenderfoot Creek counter was only partially operational due to a number of technical problems: the Logie 2100C fish counter suffered from a buffer memory power back-up problem that resulted in the loss of some data, the gates on the diversion fence were hard to maintain due to weed and debris build up, and the gates required removal during several releases of hatchery fish. As such, no defensible estimate is possible for Tenderfoot Creek coho migration in 2007, although the operational problems observed should be overcome in 2008. A total yield of 9,519 coho smolts was enumerated emigrating from the Upper Paradise complex at the old trap site in 2007 (Site 6). Combined with the provisional estimates of coho smolt yield from Kisutch channel and BC Rail channel, at least 16% of the coho smolt RST derived outmigration estimate originated from the restoration channels which were enumerated. The true value of off-channel habitat in coho production is likely higher than the calculated value as some channels were not enumerated in 2007 (i.e. Tenderfoot Creek and Gorbuscha channels). InStream Fisheries Research Inc. Page 39 5.0 SUMMARY AND RECOMMENDATIONS The objectives for the eighth year of trap operation in the Cheakamus River were largely attained, albeit not for all species and age classes at all locations. Reasons for being unable to provide robust population estimates for some outmigrants were likely due to reduced numbers of some species a result of the 2005 fish mortality and technical challenges in some new (for 2007) enumeration operations. In summary, the data we obtained included: • • • • mark-recapture data for migrating juveniles with 95% confidence intervals on the estimates of chum and chinook fry and coho smolts biological data: lengths and weights an eighth year of smolt and fry yield data with comparisons to previous sample years and to river discharge and temperature first year of side-channel production for partitioning from mainstem production Chum fry estimates were successfully generated in two channels and at the RST site, but not in the groundwater area of Upper Paradise. The methodology used for fry marking in 2007 was the same as was used in 2004 through 2006 and with the second highest ECE in the eight years of operation. This appears to be the methodology best suited to minimize stress related fry mortality and provide good quality fry estimates of yield while maximizing crew safety. The physical geography of Upper Paradise groundwater channel has been altered since the study was designed and as a result the area available for evaluation is now much reduced in size. As such, using the methods proposed in the study plan failed to capture sufficient fish for marking purposes and to provide a reliable yield estimate. To rectify this problem it is proposed that in the spring of 2008 the enumerator trap (Site B) be used to capture fish for marking which will then be re-released upstream (as in the RST estimate). The fyke net and trap box which will be made available by this change will instead be utilized in BC Rail channel in 2008 for fry enumeration, creating an additional yield estimate for chum fry in a groundwater channel. As adult chum escapement data was collected at BC Rail channel in the fall of 2007 (Monitor 1b, Troffe & McCubbing, in prep) this addition will allow for calculation of egg deposition to fry survival estimates in a groundwater channel. Page 40 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Juvenile outmigrant fish catches of steelhead and chinook smolts at the RST in 2007 indicate that the fish kill resulting from the 2005 NaOH spill event likely had an ongoing detrimental effect on chinook and steelhead production in the Cheakamus River. We observed low numbers of these fish despite high capture efficiencies of other species, including coho smolts, and as a result no estimate could be derived for chinook salmon or steelhead trout smolts in this study year. Estimated coho smolt (1 year in age, so unaffected by the fish kill) abundance, in comparison, was towards the upper range of historic estimates, with length and weight data indicating that some density dependant growth limitation might have occurred (smallest fish in eight study years). Alterations to the NVOS restoration channels and coho release strategies at Tenderfoot Hatchery have occurred since the RST program began marking side-channel coho smolts in 2001, resulting in only Upper Paradise channel being utilized in 2004 through 2007 to capture side-channel coho smolts for marking. The new coho smolt enumeration facility proposed within the Cheakamus Water Use Plan: Monitoring Program Terms of Reference, Monitor 1a, Feb, 2007, is under development. This new trap will capture all smolts originating from the entire NVOS channel complex (Site1; Figure 2.). This trap would increase the sample size of coho available for marking to meet or exceed the number of fish marked prior to alterations to channels and hatchery release strategies. It may also capture sufficient numbers of steelhead smolts to develop robust population estimates for these species in years when an estimate derived from RST marked fish is not possible. New RST drums with an increased mesh size were utilized from mid May through to the end of May. From visual observations, these drums appear to have increased water flow and reduced drag, likely allowing for the increases in capture efficiency of smolts. Further data are required on drum rotation rates, intake velocities and trap efficiency to verify these assumptions. Additional improvements in infrastructure including permanent moorings with increased cable tolerances and the option to operate a third RST will also allow for improvements in trap operations at elevated flows and during periodic flood events with increased river discharge and water velocities. Estimates of coho smolt output derived from trapping were generated for Upper Paradise complex and Upper Paradise groundwater section. In the later case, the groundwater section of channel available for rearing is now so restricted that we cannot be sure that the few smolts captured were in fact generated from this area and not simply coho smolts that moved into the channel section immediately prior to trap set-up and operation. As such, we propose the suspension of smolt trapping operations at this location and movement of equipment to Tenderfoot Creek to assist in assessments at that location. Site development to InStream Fisheries Research Inc. Page 41 provide a method to evaluate smolt yield from the entire NVOS complex are ongoing, with sill construction completed in the summer of 2007. Additional work is yet required for this site to be fully operational in 2008. Enumeration of coho smolts was undertaken this year for the first time on BC Rail and Kisutch channels and Tenderfoot Creek using novel resistivity counter techniques. This was attempted using equipment available from the planned chum adult monitor (1b). The method was utilized to reduce handling stress on coho smolts and manpower requirements of manually trapping and counting fish. While results in 2007 are initially disappointing, changes to counter design and operations are proposed for the spring of 2008, which should improve yield estimates and in part confirm 2007 preliminary evaluations and analysis. These improvements will include: decreased spacing of electrodes to 5cm in all sensor tubes to increase peak signal sizes generated by coho smolts, construction of a low-head backwater structure at BC Rail to reduce air entrainment noise, increased sensor tube deployment (from 2 to 4) at Tenderfoot Creek to facilitate increased fish passage, and redesign of fence screen panels and rails at Tenderfoot to reduce debris build-up. The use of solar panels at some sites will be considered to decrease the frequency of battery changes and increase power available for video validation. Counter efficiency validation will be primarily undertaken by the operation of trap boxes on the outflow tubes in 2007 so that if the proposed changes are not found to improve the resistivity counter to an acceptable level, a reliable outmigrant estimate will still be generated. A decision on operations post 2008 will depend on the results obtained following these improvements. An improved statistical method of assessing the utility of RST derived yield estimates to track variations in smolt and fry production is being developed. This will be used to evaluate current statistical analysis methods and linkages between estimated yields and inter-annual river discharge. Current evidence of the precision of annual yield estimates indicates the potential for the use of this data in assessing the reasons for annual yield variances, but we must be certain they are real changes in yield and not artifacts of data collection methods. The current time series of data is being used to ground truth modeling exercises which seek to examine the effects of run timing and river discharge on the confidence of smolt yield estimates (J. Korman, Ecometric Ltd, pers. comm.). Page 42 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   After one full year of discharges affected by the WUP (February 2006 through February 2007), the estimated outmigration yields of chum and chinook fry and coho smolts were above the average of those yields reported during pre WUP flow requirements years (Melville & McCubbing, 2006). However, further years’ data are yet required to assess if steelhead and chinook smolt productivity are similarly affected and to what extent annual variances in the productivity of all ages of juvenile salmonids occurs. These will likely be affected by the WUP flow order, natural flood events, and changes in species assemblages as a result of watershed recovery from the 2005 chemical spill. InStream Fisheries Research Inc. Page 43 6.0 TABLES Table 1. Start and end dates for all traps and counters operated on the Cheakamus River, Spring 2007. Trap/Counter Name RST1 RST2 Upper Paradise smolt mark trap (Site 6) Little Gorbushca 1(Site E) Big Gorbushca 1(Site G) Upper Paradise Fyke 1 (Site A) Kisutch Fyke 1 (Site C) Upper Paradise Fyke 3 (Site I) Upper Paradise Fyke 2 (Site B) Kisutch Fyke 2 (Site D) NVOS side channel complex Fyke (Site F) (Upper) Upper Paradise smolt trap (Site 2) Kisutch Smolt Counter (Site 3) BC Rail Counter (Site 4) Tenderfoot Counter (Site 5) Start Date Feb. 16 Feb. 21 April 2 March 20 April 4 March 29 March 27 March 26 March 30 March 27 March 17 April 9 April 8 April 4 April 12 End Date May 31 May 31 June 3 May 10 May 10 May 10 May 10 April 2 May 11 May 14 May 16 June 3 June 8 June 4 May 30 Comments Larger mesh drums installed on May 18 Larger mesh drums installed on May 18 Upstream smolt marking Upstream side-channel fry marking Upstream side-channel fry marking Upstream side-channel fry marking Upstream side-channel fry marking Upstream side-channel fry marking Downstream side-channel fry enumerator Downstream side-channel fry enumerator Downstream side-channel fry enumerator Total capture fish trap Counter estimate Counter estimate Counter estimate Page 44 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Table 2. Annual dates of 90% capture of chum, chinook, and pink fry at the RST site on the Cheakamus River, 2001 to 2006. Year 2001 2002 2003 2004 2005 2006 Chum Fry April 20 April 25 May 6 April 25 April 26 April 30 Chinook Fry (<70mm) May 2 April 3 April 24 May 19 April 14 May 11 Pink Fry n/a April 10 n/a April 9 n/a April 9 Table 3. Trap dates for which trap operation was limited or suspended (1 day = 24 hrs). Trap Dates not in operation Limited operation (continuous monitoring pulled ~2am) Comments Trap #2Trap #1 & 2 Trap #1 & 2 Trap #1 & 2 Trap #2 Trap #1& 2 Trap #1 & 2 Trap #1 Trap #1 & 2 Fyke Net Site F Fyke Net Site D Feb. 16 to 20 (5 days) March 12 & 13 (2 days) March 18 (1 day) March 20 (1 day) March 25 (1 day) April 24 (1 day) April 28 (1 day) April 29 (1 day) May 4 & 5 (2 days) April 10, May 5, 12, 13 & 14 March 30 & April 6 Low Flow High flow High flow High flow High flow Hatchery release High flow Trap malfunction Hatchery release Hatchery release Trap malfunction InStream Fisheries Research Inc. Page 45 Table 4. Eight year summary of fish caught and marked at the rotary screw trap and side-channels on the Cheakamus River. Species Chum Fry Chum Fry Chum Fry Chum Fry Chum Fry Chum Fry Chum Fry Chum Fry Year Total Caught 2000 2001 2002 2003 2004 2005 2006 2007 54,527 120,742 103,932 65,505 135,372 173,924 354,337 395,378 Total Marked 8,415 43,520 23,685 12,239 63,005 62,283 94,285 82,827 Total Recap 109 3,557 1,101 193 2,775 4,425 7,798 6,975 ECE % 1.3 8.2 4.6 1.6 4.4 7.1 8.5 8.4 PPE 3,889,974 1,486,982 1,967,233 4,066,391 3,134,252 2,509,793 4,270,934 4,635,606 Chinook Fry Chinook Fry Chinook Fry Chinook Fry Chinook Fry Chinook Fry Chinook Fry Chinook Fry 2000 2001 2002 2003 2004 2005 2006 2007 1,537 8,558 7,554 5,758 733 917 499 8,742 185 3,111 1,571 2,435 300 329 n/a 2,853 3 220 91 75 4 4 n/a 146 1.6 7.1 5.8 3.1 1.3 1.2 n/a 5.1 n/a 119,841 130,646 212,796 44,426 60,851 n/a 150,374 Pink Fry Pink Fry Pink Fry Pink Fry Pink Fry Pink Fry Pink Fry Pink Fry 2000 2001 2002 2003 2004 2005 2006 2007 1 1 1 1,241 8 26,876 0 2,844 3 41,418 19 156 n/a 5,304 n/a 1,521 n/a 10,811 n/a 0 n/a 113 n/a 53 n/a 1,567 n/a 0 n/a 2.1 n/a 3.5 n/a 14.5 n/a n/a n/a 1,255,981 n/a 81,679 n/a 296,405 n/a 1. “off” brood years for pink salmon on the Cheakamus River. Table 4 (cont.) Page 46 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Species Coho Fry Coho Fry Coho Fry Coho Fry Coho Fry Coho Fry Coho Fry Coho Fry Year Total Caught 2000 2001 2002 2003 2004 2005 2006 2007 1,088 5,295 1,239 2,163 3,121 597 2,638 10,691 Total Marked n/a n/a n/a n/a n/a n/a n/a n/a Total Recap n/a n/a n/a n/a n/a n/a n/a n/a ECE % n/a n/a n/a n/a n/a n/a n/a n/a PPE n/a n/a n/a n/a n/a n/a n/a n/a InStream Fisheries Research Inc. Page 47 Table 4 (cont.) Species Chinook Smolt Chinook Smolt Chinook Smolt Chinook Smolt Chinook Smolt Chinook Smolt Chinook Smolt Chinook Smolt Year Total Caught 2000 2001 2002 2003 2004 2005 2006 2007 348 313 89 81 4 2 1 47 Total Marked 158 254 62 55 n/a n/a n/a n/a Total Recap 28 33 2 3 n/a n/a n/a n/a ECE% 17.7 13.0 3.2 5.5 n/a n/a n/a n/a PPE 2133 2984 1931 1189 n/a n/a n/a n/a RST Steelhead Smolt RST Steelhead Smolt RST Steelhead Smolt RST Steelhead Smolt RST Steelhead Smolt RST Steelhead Smolt RST Steelhead Smolt RST Steelhead Smolt UP2 Steelhead Smolt UP Steelhead Smolt UP Steelhead Smolt UP Steelhead Smolt UP Steelhead Smolt UP Steelhead Smolt UP Steelhead Smolt 2000 2001 2002 2003 2004 2005 2006 2007 429 207 115 373 9 21 5 20 238 154 76 287 n/a n/a n/a n/a 23 12 2 23 n/a n/a n/a n/a 9.7 7.8 2.6 8.0 n/a n/a n/a n/a 4281 2467 3028 4583 n/a n/a n/a n/a 2001 2002 2003 2004 2005 2006 2007 138 125 78 54 38 13 30 n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a Page 48 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Species RST Steelhead Parr RST Steelhead Parr RST Steelhead Parr RST Steelhead Parr RST Steelhead Parr RST Steelhead Parr RST Steelhead Parr RST Steelhead Parr Year 2000 2001 2002 2003 2004 2005 2006 2007 Total Caught 136 238 143 256 36 42 6 621 Total Marked n/a n/a n/a n/a n/a n/a n/a n/a Total Recap n/a n/a n/a n/a n/a n/a n/a n/a ECE% n/a n/a n/a n/a n/a n/a n/a n/a PPE n/a n/a n/a n/a n/a n/a n/a n/a UP2 Steelhead Parr UP Steelhead Parr UP Steelhead Parr UP Steelhead Parr UP Steelhead Parr UP Steelhead Parr UP Steelhead Parr 2001 2002 2003 2004 2005 2006 2007 132 159 387 660 73 14 371 n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a RST Coho Smolt RST Coho Smolt RST Coho Smolt RST Coho Smolt RST Coho Smolt RST Coho Smolt RST Coho Smolt RST Coho Smolt 2000 2001 2002 2003 2004 2005 2006 2007 11,177 6,394 3,120 7,616 1,238 1,618 1,379 7,235 7,222 2,517 1,382 4,129 755 1,060 757 6,031 1,478 400 112 500 30 61 49 625 20.5 15.9 8.1 12.1 4.0 5.8 6.5 10.4 61244 39960 35726 66911 32557 28748 21602 80737 SC Coho Smolt SC Coho Smolt SC Coho Smolt SC Coho Smolt SC Coho Smolt SC Coho Smolt SC Coho Smolt SC Coho Smolt 2000 2001 2002 2003 2004 2005 3 3 n/a 30,616 21,221 28,666 10,588 4,580 5,472 9,159 n/a 29,883 17,861 24,606 8,249 3,355 4,578 7,422 n/a 2,851 813 1,812 175 138 173 676 n/a 9.3 4.6 7.4 2.1 4.1 3.8 9.1 n/a 67298 68484 127974 66186 39087 36209 85018 20063 2007 3 2. For side-channel steelhead numbers, only Upper Paradise trap catch is reported 3. Only Upper Paradise trap operated (in previous years Tenderfoot and Kisutch were used). InStream Fisheries Research Inc. Page 49 Table 5. Summary of size ranges for age classes of salmonid and trout species on the Cheakamus River, Spring 2007 Species Coho smolt Coho Fry Steelhead Smolt Steelhead Parr Early Chinook Fry (Feb. & March) Late Chinook Fry (April & May Chinook Smolts Age(s) 1+ 0+/YOY 2+ and 3+ 1+ 0+ (YOY) Brood year(s) 2005 2006 2005 & 2004 2006 2006 Code COS COF SHS SHP CHF Size range > 70mm < 70mm > 140mm < 140mm < 70mm Reference Cheakmus length frequency data (2000-2006) Cheakmus length frequency data (2000-2006) Melville & McCubbing, 2005, Korman & McCubbing 2007 Melville & McCubbing, 2005, Korman & McCubbing 2007 Cheakmus length frequency data (2000-2006) Cheakmus length frequency data (2000-2006) Cheakmus length frequency data (2000-2006) 0+ (YOY) 2006 CHF 70-90mm 1+ 2005 CHS >90mm Page 50 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Table 6. Summary of length & weight data from fish captured at the rotary screw traps on the Cheakamus River, Spring 2007. Species Chum Fry Length (mm) 525 30-54 38 2.3 247 32-58 38 5.4 194 32-66 41 5.4 n/a n/a n/a n/a 393 28-53 36 2.5 18 140-190 163 20.5 569 60-139 92 14.6 509 60-116 88 10.9 1227 55-135 91 10.6 Weight (g) 122 0.3-0.6 0.4 122 71 0.3-2.2 0.6 0.3 48 0.3-0.7 0.6 0.2 n/a n/a n/a n/a 110 0.2-0.6 1.8 1.3 14 27.2-74.5 47.4 17.8 546 2.3-31.8 9.6 4.7 383 2.3-100 8.5 5.5 435 2.6-22.1 8.5 2.9 Chinook Fry (early - prior to April 15) Chinook Fry (late - after April 15) Pink Fry Coho Fry Steelhead Smolts Steelhead Parr Coho Smolts (RST) Coho Smolts (SC) N Range Mean SD N Range Mean SD N Range Mean SD N Range Mean SD N Range Mean SD N Range Mean SD N Range Mean SD N Range Mean SD N Range Mean SD InStream Fisheries Research Inc. Page 51 Table 7. Summary of mean lengths 2000-2007 from the Cheakamus River. Species Chum Fry Year 2000 2001 2002 2003 2004 2005 2006 2007 Year 2000 2001 2002 2003 2004 2005 2006 2007 Year 2000 2001 2002 2003 2004 2005 2006 2007 Year n/a 2001 2002 2003 2004 2005 2006 2007 N 59 404 491 403 324 225 274 525 N n/a n/a 358 n/a 53 n/a 164 n/a N 67 490 419 191 68 22 7 247 N n/a 49 217 184 139 n/a 124 393 Mean Length 42 40 39 41 38 39 39 38 Mean Length n/a n/a 34 n/a 34 n/a 34 n/a Mean Length 55 48 43 50 40 44 42 38 Mean Length n/a 35 43 38 36 n/a 34 36 Species Pink Fry Species Chinook Fry (early) Species Coho Fry Page 52 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Table 7. continued Year N Mean Length 2000 123 100 20011 n/a n/a 2002 25 108 2003 13 111 2004 2 90 2005 1 103 2006 1 95 2007 34 103 1 . Sample not included due to hatchery chinook smolts being sampled and not differentiated from wild. Species Steelhead Smolts Year 2000 2001 2002 2003 2004 2005 2006 2007 Year 2000 2001 2002 2003 2004 2005 2006 2007 Year 2000 2001 2002 2003 2004 2005 2006 2007 N 138 110 43 90 5 57 23 18 N 63 169 104 194 38 53 24 573 N 1180 893 818 1114 244 477 394 509 Mean Length 170 176 175 178 156 176 177 166 Mean Length 79 84 82 81 88 88 118 93 Mean Length 94 91 93 93 93 92 96 88 Species Chinook Smolts Species Steelhead Parr Species RST Coho Smolts InStream Fisheries Research Inc. Page 53 Table 7. continued Species Side Channel Coho Smolts Year 2000 2001 2002 2003 2004 2005 2006 2007 N n/a 5416 3229 3334 1298 1187 939 1227 Mean Length n/a 90 96 95 93 96 93 91 Table 8. Preliminary estimates of coho smolt migration from Cheakamus side-channel electronic counters & traps, Spring 2007. Counter/Weir Site Upper Paradise/Gorbushca Weir (Site 1) (upper) Upper Paradise Weir (Site 2) Kisutch (Site 3) BC Rail (Site 4) Tenderfoot Creek (Site 5) Coho smolt count/estimate Not run in 2007 43 2122 1064 n/a Page 54 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   7.0 FIGURES Figure 1. Cheakamus River watershed indicating Reaches 1 through 9, WSC gauging station, temperature loggers, and RST trap location. InStream Fisheries Research Inc. Page 55 Figure 2. Site Map indicating trap sites utilized in 2007 on the Cheakamus River. Page 56 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Schematic of Side‐channel Fry Production   Marking Fyke traps and enumerator fyke traps    Upper Paradise    Marking Fyke (Site A)      Kisutch      Marking Fyke (Site C)      Little Gorbushca    Marking Fyke (Site E)      Big Gorbushca     Marking Fyke (Site G)                            Upper Paradise       Enumerator Fyke (Site B)    Assessment of Groundwater   Channel Production              Upper Paradise     Additional Marking Fyke (Site H)          Kisutch            Enumerator Fyke (Site D)  Assessment of Groundwater   Channel Production                                                  Upper Paradise/Gorbushca Fyke  Enumerator Fyke (Site F)  Recaptures from all marking fyke net traps  Assessment of Groundwater and Augmented  NVOS Side‐channel Complex  Figure 3. Diagram of side-channel fry production marking and enumerator sites in the Upper Paradise/Gorbushca side-channel complex, Spring 2007. InStream Fisheries Research Inc. Page 57 Upper Paradise Trap Site 2 Total Capture Trap Kisutch Counter Site 3 Resistivity Counter BC Rail Counter Site 4 Resistivity Counter Tenderfoot Counter Site 5 Resistivity Counter n Upper Paradise Trap (old) Site 6 Total Capture Trap Upper Paradise/Gorbushca Site 1**** Total Capture Trap ****Not operated in Spring 2007 due to logistical issues that precluded installation. Will eventually replace Site 6. Figure 4. Diagram of side-channel smolt production trap and counter sites, Spring 2007. Page 58 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Mainstem Chum, Chinook   and   Pink Fry Mark‐Recapture   Production Schematic            Upstream RST Marked Fish Release Site                   Rotary Screw Trap 1&2  Mark site  &   Recapture site  Produce population estimate for   chum, chinook and pink fry      Figure 5. Diagram of Cheakamus mainstem fry production estimate marking and recapture sites, Spring 2007. InStream Fisheries Research Inc. Page 59 Mainstem Smolt Mark‐Recapture   Production Schematic             Upstream Upper Paradise (UP)   Marking Trap Site 6*****   Total Capture trap   Mark coho smolts          Upstream RST Marked Eagle Point Fish Release Site                   Rotary Screw Trap (RST) 1&2  Mark site   &  Recapture site  Produce 2 population estimates (RST & UP) for  coho and 1 for steelhead and chinook (RST)      *****Note that this trap site has been operated to obtain coho to mark since 2001. In 2008 this site will be moved to Upper Paradise/Gorbushca Site 1.  Figure 6. Diagram of Cheakamus mainstem smolt production estimate marking and recapture sites, Spring 2007. Page 60 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Figure 7. Mean Daily Discharge from Water Survey of Canada Station 08GA043 Cheakamus at Brackendale. Spring 2007. InStream Fisheries Research Inc. Page 61 10 9 8 Temperature in Degrees C 7 6 5 4 3 2 1 0 16-Feb-07 23-Feb-07 18-May-07 25-May-07 11-May-07 16-Mar-07 23-Mar-07 30-Mar-07 15-Jun-07 1-Jun-07 9-Feb-07 13-Apr-07 20-Apr-07 27-Apr-07 4-May-07 8-Jun-07 2-Mar-07 9-Mar-07 6-Apr-07 Date Figure 8. Average Daily Water Temperature in oC, of the Cheakamus River, as recorded by a logger located at the trap site, Spring 2007. Page 62 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Figure 9. Weekly catch summary of chum fry (solid line, squares) related to temperature in oC (broken line, triangles) and discharge (solid line) from the Cheakamus River, Spring 2007. InStream Fisheries Research Inc. Page 63 Figure 10. Weekly catch summary of chinook fry (solid line, squares) related to temperature in oC (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007. Page 64 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Figure 11. Length frequency distribution of chinook juveniles from the Cheakamus River, Spring 2007. InStream Fisheries Research Inc. Page 65 Figure 12. Weekly catch summary of steelhead smolts (solid line, squares) related to temperature in o C (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007. Page 66 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   o Figure 13. Weekly catch summary of steelhead parr (solid line, squares) related to temperature in C (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007. InStream Fisheries Research Inc. Page 67 Figure 14. Length frequency distribution of steelhead juveniles sampled on the Cheakamus River, Spring 2007. Page 68 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Figure 15. Weekly catch summary of coho smolts (solid line, squares) related to temperature in oC (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007. InStream Fisheries Research Inc. Page 69 Figure 16. Weekly catch summary of coho fry (solid line, squares) related to temperature in oC (broken line, triangles) and flow (solid line) on the Cheakamus River, Spring 2007. Page 70 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Figure 17. Length frequency distribution of coho juveniles from the Cheakamus River, Spring 2007. InStream Fisheries Research Inc. Page 71 2500 2000 No. of Records 1500 1000 500 0 10 20 30 40 50 60 70 PSS 80 90 100 110 120 More Figure 18. Peak Signal Size of Records at the Kisutch channel fish counter, Spring 2007. 300 250 200 150 100 50 0 08 /0 4/ 20 07 15 /0 4/ 20 07 22 /0 4/ 20 07 29 /0 4/ 20 07 06 /0 5/ 20 07 13 /0 5/ 20 07 20 /0 5/ 20 07 27 /0 5/ 20 07 03 /0 6/ 20 07 up event down Count of fish Date Figure 19. Up, event and down counts of fish with PSS <80 at Kisutch channel, Spring 2007. Page 72 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   140 120 Counts per day 100 80 60 40 20 0 09/04/2007 16/04/2007 23/04/2007 30/04/2007 07/05/2007 14/05/2007 21/05/2007 28/05/2007 04/06/2007 up event down Date Figure 20. Up, event and down counts of fish with PSS <80 at BC Rail channel, Spring 2007. 30 25 up event down No. of Counts 20 15 10 5 0 Figure 21. Up, event and down counts of fish with PSS >80 at BC Rail channel, Spring 2007. InStream Fisheries Research Inc. 09 /0 4/ 20 07 16 /0 4/ 20 07 23 /0 4/ 20 07 30 /0 4/ 20 07 07 /0 5/ 20 07 14 /0 5/ 20 07 21 /0 5/ 20 07 28 /0 5/ 20 07 04 /0 6/ 20 07 Date Page 73 Figure 22. Pooled Petersen Estimates of chum fry from Spring 2000 to 2007, including 95% confidence limits. Page 74 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Figure 23. Pooled Petersen Estimates of chinook fry from Spring 2001 to 2007, including 95% confidence limits. InStream Fisheries Research Inc. Page 75 Figure 24. Pooled Petersen Estimates of chinook smolts from Spring 2000 to 2007, including 95% confidence limits. Page 76 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Figure 25. Pooled Petersen Estimates of steelhead smolts from Spring 2000 to 2007, including 95% confidence limits. InStream Fisheries Research Inc. Page 77 Figure 26. Pooled Petersen Estimates of coho smolts captured and marked at the RST site from Spring 2000 to 2007, including 95% confidence limits. Page 78 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Figure 27. Pooled Petersen Estimates of mainstem coho smolts out-migration, calculated using coho smolts captured and marked at the side-channels from Spring 2000 to 2007, including 95% confidence limits. InStream Fisheries Research Inc. Page 79 Figure 28. Comparison of population estimates of coho smolts derived from RST marked fish (solid black bar) and side-channel marked fish (diagonal striped bar) from 2001 to 2007 on the Cheakamus River. Page 80 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   8.0 REFERENCES AFS Salmonid Field Protocols Handbook: Techniques for assessing status and trends in salmon and trout populations. Chapter 8. Ed. D.H. Johnson, B.M. Shrier, J.S. O'Neal, J.A. Knutzen, X. Augerot, T.A. O'Neil, T.N. Pearsons Available from American Fisheries Society May 2007 Arnason, A.N., C.W. Kirby, C.J. Schwarz, and J.R. Irvine. 1996. Computer analysis of data from stratified mark-recovery experiments for the estimation of salmon escapements and other populations. Can. Tech. Rep. Fish. Aquat. Sci. 2106 37p. Aprahamian, M.W., S.M. Nicholson, D.J.F. McCubbing, and I. Davidson. 1996. The use of resistivity fish counters in fish stock assessment. In Stock Assessment in Inland Waters ed I.Cowx Chapter 3, 2743. Bonner S.J & C.J. Shwartz 2007a. Bayesian smoothing of stratified Peterson model. Contract report for BC Hydro. 6p. Bonner S.J & C.J. Shwartz 2007b. Analysis of Cheakamus salmon capture re-capture data. Technical report for BC Hydro. 14p. Cheakamus Water Use Plan: Monitoring Program Terms of Reference, Revision 1, February 2007, Water Use Planning, BC Hydro www.bchydro.com/rx_files/environment/environment50634.pdf, Cope, S. 1999. Alouette River salmonid smolt migration enumeration: 1999 data report. Alouette River Management Committee Contract Report. 33p. Dunkley, D.A. 1991. The use of fish counters in the management of salmonid stocks: the example of the North Esk. Proceedings of the Institute of Fisheries Management. 22nd Annual Study Course, Aberdeen 1991, 153-158. Decker, A.S. 1998. Influence of off-channel habitat restoration and other enhancement on the abundance and distribution of salmonids in the Coquitlam River. Report prepared for B.C. Hydro, Power Facilities, Burnaby, B.C. and Department of Fisheries and Oceans Resource Restoration Division, Vancouver, B.C. Fewings,G.A. 1987. The validation of two resistivity counters using infra-red telesurveillance at two sites in the North West of England. MSc Thesis, University College of North Wales, Bangor, Wales. Frith, H.R., T.C. Nelson, and C.J. Schwarz. 1995. Mark-recapture estimates of coho and steelhead outmigration derived from rotary trap recaptures of marked fish for the Waukwaas River in 1995. Prepared for Ministry of Environment, Lands and Parks by LGL Limited. 34p. Hart, P.J., and T.J. Pritcher. 1969. Field trials of fish marking using a jet inoculator. J. Fish. Bio. 1: 383-385. Ladell, J., J. Korman and C. Melville. 2006 Cheakamus Char Radio Telemetry and Enumeration Program. Annual Report 2007. Prepared for Canadian National Rail Company. 20p InStream Fisheries Research Inc. Page 81 McCubbing, D.J.F. 1998. A Report on the assessment of the 1998 smolt output from the Waukwaas River, North Vancouver Island, using Rotary traps. North Vancouver Island Salmon Enhancement Society Contract Report. McCubbing, D.J.F 2003. Fish Counter enumeration of Steelhead and rainbow Trout on the Bonaparte River in 2003 – post fishway redesign and operational improvements. HCTF Technical Report. 31p. McCubbing, D.J.F. 1999. A Report on the assessment of the 1999 smolt output from the Waukwaas River, North Vancouver Island, using rotary traps. North Vancouver Island Salmon Enhancement Society Contract Report. 19p. McCubbing, D.J.F., and C.C. Melville. 1999. Chinook spawning migration patterns in the Cheakamus River, based on radio tracking observations in the summer of 1999. Instream Fisheries Consultants Project Report for BC Hydro Water Use Planning. McCubbing, D.J.F. 2000. A Report on the assessment of the 2000 smolt output from the Waukwaas River, North Vancouver Island, using rotary traps. North Vancouver Island Salmon Enhancement Society (NVISEA) Contract Report nos 800535. McCubbing, D.J.F. 2000. Adult Steelhead Trout and Salmonid Smolt Migration at the Keogh River during Spring 2000. NVISEA Contract Report no. 800534. McCubbing, D.J.F. 2001a. A Report on the assessment of the 2001 smolt output from the Waukwaas River, North Vancouver Island, using rotary traps. North Vancouver Island Salmon Enhancement Society (NVISEA) MWALP Contract Report. McCubbing, D.J.F. 2001b. Adult Steelhead Trout and Salmonid Smolt Migration at the Keogh River during Spring 2001. NVISEA MWALP Contract Report. McCubbing, D. and G. Andrusak. 2006. Lardeau River Fish Counter 2006 Gerrard Rainbow Trout Enumeration Report. HCTF Technical Report 22p. McCubbing, D.J.F. 2003. Deadman River Electronic Enumeration Fence Analysis and Training. Fisheries Renewal Research Report. FS99-18,13p. McCubbing, D.J.F., and B.R. Ward. 2002. Adult Steelhead Trout and Salmonid Smolt Migration at the Keogh River, B.C. during Spring 2002. Habitat Conservation Trust Fund Contract Number: CBIO3006. 41p. McCubbing, D.J.F., and B.R. Ward. 2003. Adult Steelhead Trout and Salmonid Smolt Migration at the Keogh River, B.C. during Winter and Spring 2003. Habitat Conservation Trust Fund Contract Number: CBIO4051. 43p. McCubbing, D.J.F., C.C. Melville, G. Wilson and M. Foy. 2006. Assessment of the CN sodium hydroxide spill August 5th, 2005 on the fish populations of the Cheakamus River. Report for Ministry of Environment and Cheakamus Ecological Recovery Technical Committee. 131p. McCubbing, D.J F., Ward, B and L. Burroughs. 1999. Electronic enumeration of salmonids on the Keogh River: a demonstration of a resistivity counter in British Columbia. Province of Bc. Fisheries Technical Circular. No 104:25p. Page 82 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Marmorek,D.R & I.Parnell 2002. Cheakamus River water use plan: report of the consultative committee. B.C.Hydro. Burnaby, B.C. 235p. Melville, C.C. 1996. Waukwass River assessment of smolt migration using rotary traps. British Columbia Conservation Foundation Contract Report for MoELP. Melville, C.C. 1997. Waukwass River assessment of smolt migration using rotary traps. British Columbia Conservation Foundation Contract Report for MoELP. Melville C.C and D.J.F. McCubbing. 2001. Assessment of the 2000 Juvenile Salmon Migration from the Cheakamus River, using Rotary Traps. BC Hydro WUP Report. 42p. Melville C.C and D.J.F. McCubbing. 2002a. Assessment of the 2001 Juvenile Salmon Migration from the Cheakamus River, using Rotary Traps. BC Hydro WUP Report. 53p. Melville C.C and D.J.F. McCubbing. 2002b. Assessment of the 2002 Juvenile Salmon Migration from the Cheakamus River, using Rotary Traps. BC Hydro WUP Report. 36p. Melville C.C and D.J.F. McCubbing. 2003. Assessment of the 2003 Juvenile Salmon Migration from the Cheakamus River, using Rotary Traps. BC Hydro WUP Report. Melville C.C and D.J.F. McCubbing. 2005. Assessment of the 2004 Juvenile Salmon Migration from the Cheakamus River, using Rotary Traps. BC Hydro WUP Report. 80p. Melville C.C and D.J.F. McCubbing. 2006. Assessment of the 2005 Juvenile Salmon Migration from the Cheakamus River, using Rotary Traps. BC Hydro WUP Report. 76p. Nicholson, S.A., M.W.Aprahamian, P.B.Best, R.A.Shaw, & E.T Kaar. 1995. Design and use of fish counters. NRA R&D Note 382. Foundation for Water Research. Liston. UK. Plante. 1990. Estimation de la taille d’une population animale a l’aide d’un modele de capture recapture avec stratification. MSc Thesis, Universite Laval Quebec. Schubert, N.D., M.K. Farwell, and L.W. Kalnin. 1994. Acoded wire tag assessment of Salmon River (Langley) coho salmon: 1991 tag application and 1992-1993 spawner enumeration. Can. Man. Fish. Aquat. Sci. 2208: 21p. Seber, G.A.F. 1982. The estimation of annual abundance and related parameters. 2nd ed. London: Griffin. Shwarz and Taylor 1998. Use of the stratified Peterson estimatorin fisheries management: estimating the number of pink salmon (Oncorhynchus gorbushca) spawners in the Fraser River. Canadian Journal of Fisheries and Aquatic Sciences55:281-296. Ricker, W.E. 1975. Computation and interpretation of biological statistics of fish populations.Bull. Fish. Res. Brd.Can. 191: 382p. Ward, B.R., and D.J.F.McCubbing. 1998. Adult steelhead and salmonid smolts at the Keogh River during spring 1998 in comparison to the historic record. Prov. B.C. Fish. Tech. Circ. No. 102. 20p. InStream Fisheries Research Inc. Page 83 Ward, B.R., D.J.F. McCubbing, and P.A. Slaney. 2003. Stream restoration for anadromous salmonids by the addition of habitat and nutrients, Pp.235-254 In D. Mills [ed.] Proceedings of the Sixth International Atlantic Salmon Symposium, July 2002, Edinburgh, Scotland. Ward, B.R., P.A. Slaney, A.R. Facchin, and R.W. Land. 1989. Size-biased survival in steelhead trout (Onchorhynchus mykiss): back-calculated lengths from adult’s scales compared to migrating smolts at the Keogh River, British Columbia. Can. J. Fish. Aquat. Sci.46:1853- 1858. Page 84 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   APPENDICES Appendix 1-A. Mainstem (RST) Catch and Population Estimate Summary: Spring 2007. +95% -95% Estimated Pooled Total Total Total Total Peterson Confid. Confid. Catch Chum Chum Chum Chum Limit Limit Efficiency Estimate Fry Fry Fry Fry (ECE%) Recap. Marked (mort) (live) 390,632 4,746 82,827 6,975 8.4 4,635,606 4,738,769 4,532,441 Total Pink Fry (live) 19 Total Chinook Fry (live) 8,573 Total Chinook Smolts (live) 47 Total Steelhead Smolts (live) 20 Total Pink Fry (mort) n/a Total Chinook Fry (mort) 169 Total Chinook Smolts (mort) 0 Total Steelhead Smolts (mort) 0 Total Pink Fry Marked n/a Total Chinook Fry Marked 2,853 Total Chinook Smolts Marked N/A Total Steelhead Smolts Marked 0 Total Pink Fry Recap. n/a Total Chinook Fry Recap. 146 Total Chinook Smolts Recap. N/A Total Steelhead Smolts Recap. N/A Estimated Catch Efficiency (ECE%) n/a Estimated Catch Efficiency (ECE%) 5.1 Estimated Catch Efficiency (ECE%) N/A Estimated Catch Efficiency (ECE%) N/A Pooled Peterson Estimate n/a Pooled Peterson Estimate 126,002 Pooled Peterson Estimate N/A Pooled Peterson Estimate N/A +95% Confid. Limit n/a +95% Confid. Limit 145,547 +95% Confid. Limit +95% Confid. Limit -95% Confid. Limit n/a -95% Confid. Limit 106,456 -95% Confid. Limit -95% Confid. Limit M.L. Darroch Estimate 4,515,933 M.L. Darroch Estimate n/a M.L. Darroch Estimate 194,327 M.L. Darroch Estimate N/A M.L. Darroch Estimate N/A +95% Confid. Limit 4,628,045 +95% Confid. Limit n/a +95% Confid. Limit 310,198 +95% Confid. Limit +95% Confid. Limit -95% Confid. Limit 4,403,821 -95% Confid. Limit n/a -95% Confid. Limit 78,457 -95% Confid. Limit -95% Confid. Limit - InStream Fisheries Research Inc. Page 85 Appendix 1-A continued. Mainstem (RST) Catch and Population Estimate Summary: Spring 2007. Total Steelhead Parr (live) 621 Total RST Coho Smolts (live) 7,233 Total SC Coho Smolts (live) 9,159 Total Coho Fry (live) 10,691 Total Steelhead Parr (mort) 0 Total RST Coho Smolts (mort) 2 Total SC Coho Smolts (mort) 0 Total Coho Fry (mort) 16 Total Steelhead Parr Marked 0 Total RST Coho Smolts Marked 6,031 Total SC Coho Smolts Marked 7,422 Total Coho Fry Marked 0 Total Steelhead Parr Recap. N/A Total RST Coho Smolts Recap. 625 Total SC Coho Smolts Recap. 676 Total Coho Fry Recap. N/A Estimated Catch Efficiency (ECE%) N/A Estimated Catch Efficiency (ECE%) 10.4 Estimated Catch Efficiency (ECE%) 9.1 Estimated Catch Efficiency (ECE%) N/A Pooled Peterson Estimate N/A Pooled Peterson Estimate 80,737 Pooled Peterson Estimate 85,018 Pooled Peterson Estimate N/A +95% Confid. Limit N/A +95% Confid. Limit 86,492 +95% Confid. Limit 90,846 +95% Confid. Limit N/A -95% Confid. Limit N/A -95% Confid. Limit 74,982 -95% Confid. Limit 79,189 -95% Confid. Limit N/A M.L. Darroch Estimate N/A M.L. Darroch Estimate 96,990 M.L. Darroch Estimate 102,107 M.L. Darroch Estimate N/A +95% Confid. Limit N/A +95% Confid. Limit 111,119 +95% Confid. Limit 114,891 +95% Confid. Limit N/A -95% Confid. Limit N/A -95% Confid. Limit 82,781 -95% Confid. Limit 89,396 -95% Confid. Limit N/A Page 86 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Appendix 1-B: Side-channel Catch and Population Estimate Summary: Spring 2007. UPGF (Site F) Chum fry (live) 218,046 KF2 (Site D) Chum fry (live) 13,879 UPF2 (Site B) Chum fry (live) 9,019 UPGF (Site F) Chum fry (mort) 3,152 KF2 (Site D) Chum fry (mort) 216 UPF2 (Site B) Chum fry (mort) 98 UPGF (Site F) Chum fry Marked 11,309 KF2 (Site D) Chum fry Marked 7,549 UPF2 (Site B) Chum fry Marked 808 UPGF (Site F) Chum fry Recap. 933 KF2 (Site D) Chum fry Recap. 211 UPF2 (Site B) Chum fry Recap. 20 Estimated Catch Efficiency (ECE%) 8.3 Estimated Catch Efficiency (ECE%) 2.8 Estimated Catch Efficiency (ECE%) 2.5 Pooled Peterson Estimate 1,673,636 Pooled Peterson Estimate 501,504 Pooled Peterson Estimate 348,254 +95% Confid. Limit 1,776,042 +95% Confid. Limit 567,400 +95% Confid. Limit 491,712 -95% Confid. Limit 1,571,231 -95% Confid. Limit 435,607 -95% Confid. Limit 204,795 M.L. Darroch Estimate N/A M.L. Darroch Estimate N/A M.L. Darroch Estimate N/A +95% Confid. Limit N/A +95% Confid. Limit N/A +95% Confid. Limit N/A -95% Confid. Limit N/A -95% Confid. Limit N/A -95% Confid. Limit N/A InStream Fisheries Research Inc. Page 87 Appendix 2-A: Mainstem Chum Fry Mark and Recovery Strata: Spring 2007. A. Chum Fry (Mainstem Marked) Recovery Stratum Release Stratum 1 2 3 4 5 6 7 8 9 10 11 Period ending 4-Mar-07 11-Mar-07 18-Mar-07 25-Mar-07 1-Apr-07 8-Apr-07 15-Apr-07 22-Apr-07 29-Apr-07 6-May-07 13-May-07 Untagged Fish Total Recovered Marked proportion Fish Marked 1635 5554 3818 6472 9645 10435 9132 10045 7612 9411 9068 223 0 0 0 0 0 0 0 0 0 0 2178 2401 9.29 8 315 0 0 0 0 0 0 0 0 0 10212 10535 3.07 0 0 328 0 0 0 0 0 0 0 0 11457 11785 2.78 0 0 1 471 0 0 0 0 0 0 0 34520 34992 1.35 0 0 0 0 1384 0 0 0 0 0 0 64914 66298 2.09 0 0 0 0 0 1257 0 0 0 0 0 95476 96733 1.30 0 0 0 0 0 0 935 0 0 0 0 57199 58134 1.61 0 0 0 0 0 0 0 825 0 0 0 43065 43890 1.88 0 0 0 0 0 0 0 0 313 0 0 21383 21696 1.44 0 0 0 0 0 0 0 0 0 441 0 18970 19411 2.27 0 0 0 0 0 0 0 0 0 0 474 17098 17572 2.70 1 2 3 4 5 6 7 8 9 10 11 Percent Recoveries 14.1 5.7 8.6 7.3 14.3 12.0 10.2 8.2 4.1 4.7 5.2 Page 88 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Appendix 2-B: NVOS Side-channel (Site F) Chum Fry Mark and Recovery Strata: Spring 2007. B. Chum fry Upper Paradise/Gorbushca Channel (UPGF Site F) Recovery Stratum Release Stratum 1 2 3 4 5 6 7 Period ending 1-Apr-07 8-Apr-07 15-Apr-07 22-Apr-07 29-Apr-07 6-May-07 13-May-07 Untagged Fish Total Recovered Marked proportion Fish Marked 3518 3727 2254 695 514 378 223 567 0 0 0 0 0 0 40332 40899 1.39 0 262 0 0 0 0 0 58088 58350 0.45 0 0 9 0 0 0 0 9455 9464 0.10 0 0 0 19 0 0 0 8771 8790 0.22 0 0 0 0 28 0 0 7055 7083 0.40 0 0 0 0 0 22 0 6874 6896 0.32 0 0 0 0 0 0 26 6703 6729 0.39 1 2 3 4 5 6 7 Percent Recoveries 16.1 7.0 0.4 2.7 5.4 5.8 11.7 InStream Fisheries Research Inc. Page 89 Appendix 2-C: Kisutch Ground Water Channel (Site D) Chum Fry Mark and Recovery Strata: Spring 2007. C. Chum Fry Kisutch Channel (KF2, Site D) Recovery Stratum Release Stratum 1 2 3 4 5 6 7 Period ending 1-Apr-07 8-Apr-07 15-Apr-07 22-Apr-07 29-Apr-07 6-May-07 13-May-07 Untagged Fish Total Recovered Marked proportion Fish Marked 1560 3228 2254 386 121 0 0 11 0 0 0 0 0 0 681 692 1.59 0 60 0 0 0 0 0 4193 4253 1.41 0 0 125 0 0 0 0 5672 5797 2.16 0 0 0 15 0 0 0 2435 2450 0.61 0 0 0 0 0 0 0 704 704 0.00 0 0 0 0 0 0 0 115 115 0.00 0 0 0 0 0 0 0 70 70 0.00 1 2 3 4 5 6 7 Percent Recoveries 0.7 1.9 5.5 3.9 0.0 0.0 0.0 Page 90 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Appendix 2-D: Upper Paradise Ground Water Channel (Site B) Chum Fry Mark and Recovery Strata: Spring 2007. D. Chum Fry Upper Paradise (UPF2, Site B) Recovery Stratum Release Stratum 1 2 3 4 5 6 7 Period ending 1-Apr-07 8-Apr-07 15-Apr-07 22-Apr-07 29-Apr-07 6-May-07 13-May-07 Untagged Fish Total Recovered Marked proportion Fish Marked 1 2 3 4 5 6 7 Percent Recoveries 87 370 0 210 87 54 0 0 0 0 0 0 0 0 318 318 0.00 0 20 0 0 0 0 0 5321 5341 0.37 0 0 0 0 0 0 0 1447 1447 0.00 0 0 0 0 0 0 0 943 943 0.00 0 0 0 0 0 0 0 519 519 0.00 0 0 0 0 0 0 0 430 430 0.00 0 0 0 0 0 0 0 41 41 0.00 0.0 5.4 0.0 0.0 0.0 0.0 0.0 InStream Fisheries Research Inc. Page 91 Appendix 2-E: Mainstem Chinook Fry Mark and Recovery Strata: Spring 2007. E. Chinook Fry (Mainstem Marked) Recovery Stratum Release Stratum 1 2 3 4 5 6 7 8 9 10 11 Period ending 4-Mar-07 11-Mar-07 18-Mar-07 25-Mar-07 1-Apr-07 8-Apr-07 15-Apr-07 22-Apr-07 29-Apr-07 6-May-07 13-May-07 Untagged Fish Total Recovered Marked proportion Fish Marked 766 665 144 41 62 104 255 239 85 145 347 48 0 0 0 0 0 0 0 0 0 0 951 999 4.80 3 27 0 0 0 0 0 0 0 0 0 1028 1058 2.84 0 0 7 0 0 0 0 0 0 0 0 263 270 2.59 0 0 0 0 0 0 0 0 0 0 0 221 221 0.00 0 0 0 0 1 0 0 0 0 0 0 316 317 0.32 0 0 0 0 0 4 0 0 0 0 0 343 347 1.15 0 0 0 0 0 0 5 0 0 0 0 856 861 0.58 0 0 0 0 0 0 0 17 0 0 0 877 894 1.90 0 0 0 0 0 0 0 0 4 0 0 222 226 1.77 0 0 0 0 0 0 0 0 0 5 0 306 311 1.61 0 0 0 0 0 0 0 0 0 0 25 960 985 2.54 1 2 3 4 5 6 7 8 9 10 11 Percent Recoveries 6.7 4.1 4.9 0.0 1.6 3.8 2.0 7.1 4.7 3.4 7.2 Page 92 InStream Fisheries Research Inc. Cheakamus Water Use Plan Juvenile Outmigration Study Spring 2007   Appendix 2-F: Mainstem (RST) Coho Smolt Mark and Recovery Strata: Spring 2007. F. Coho Smolt Mainstem (RST) Marked Recovery Stratum Release Stratum 1 2 3 4 5 6 7 Period ending 14-Apr-07 28-Apr-07 5-May-07 12-May-07 19-May-07 26-May-07 31-May-07 Untagged Fish Total Recovered Marked proportion Fish Marked 1 2 3 4 5 6 7 Percent Recoveries 180 488 411 1541 2077 822 512 15 0 0 0 0 0 0 380 395 3.80 1 23 0 0 0 0 0 616 640 3.75 0 0 10 0 0 0 0 511 521 1.92 0 0 3 177 0 0 0 1741 1921 9.37 0 0 0 37 209 0 0 2807 3053 8.06 0 0 0 0 0 71 0 1061 1132 6.27 0 0 0 0 0 28 51 637 716 11.03 8.9 4.7 3.2 13.9 10.1 12.0 10.0 InStream Fisheries Research Inc. Page 93 Appendix 2-G: Mainstem (Upper Paradise) Coho Smolt Mark and Recovery Strata: Spring 2007. G. Coho Smolt Sidechannel (UP) Marked Recovery Stratum Release Stratum 1 2 3 4 5 6 7 Period ending 14-Apr-07 28-Apr-07 5-May-07 12-May-07 19-May-07 26-May-07 31-May-07 Untagged Fish Total Recovered Marked proportion Fish Marked 60 712 688 831 2539 1822 770 4 0 0 0 0 0 0 376 380 1.05 1 25 0 0 0 0 0 593 619 4.20 0 3 13 0 0 0 0 507 523 3.06 0 0 17 74 0 0 0 1618 1709 5.32 0 0 1 19 264 0 0 2543 2827 10.05 0 0 0 0 3 152 0 900 1055 14.69 0 0 0 0 0 25 75 540 640 15.63 1 2 3 4 5 6 7 Percent Recoveries 8.3 3.9 4.5 11.2 10.5 9.7 9.7 Page 94 InStream Fisheries Research Inc.