Alouette Water Use Plan

Transcription

1 Alouette Water Use Plan Sockeye Adult Enumeration ALUMON#4 Study Period: 2009 Report Date: January 2010 Alouette River Management Society January 2010

2 Alouette Adult Sockeye Enumeration Prepared for: BC Hydro (Contact: Dave Hunter) Water Licence Requirements 6911 Southpoint Drive, E16 Burnaby, BC V3N 4X8 Prepared by: Abigail Cruickshank, B.Sc. Alouette River Management Society Alouette Road, Allco Park Maple Ridge, BC V4R 1R4 January 2010

3 Executive Summary Under BC Hydro s Water Use Plan for the Alouette Watershed, a spring surface release over the Alouette Dam has allowed for kokanee smolts to migrate to the ocean for the last five years. The first surface releases occurred in 2005 and in 2007 the first adult sockeye returned to the Alouette Watershed. The 2009 Alouette sockeye salmon run was much lower than predicted, with only 45 adults returning between the 27 th of June and the 17 th of October The sockeye were caught at the Allco Fish Hatchery and 43 were released in the Alouette Reservoir. Fork length measurements, scale and tissue samples were obtained from 15 of the returning sockeye. The measurements indicated an average fork length of 60 cm and the genetic sampling identified that all out-migrating smolts and returning adults were Alouette stock. January

4 Table of Contents Executive Summary...1 Introduction...3 Objectives...3 Study Area...3 Methods...4 Results...6 Adult Sockeye Returns...6 Fork length...8 Age Structure...8 Genetic sampling...8 Discussion...8 Adult Sockeye Returns...8 Fork Length and Age Structure...9 Genetic Analysis...10 Recommendations...10 Acknowledgements...10 References...11 Appendix A: Sockeye sampling data, Appendix B: Data on Genetic Structure of Alouette out-migrating sockeye smolts and returning sockeye adults...13 List of Figures Figure 1. Map of the Alouette Watershed...4 Figure 2. The Allco Fish Hatchery fence and trap, July Figure 3. Sockeye transport tanks, August Figure 4. Sockeye transport tank with release slide connected, January Figure 5. Sockeye # 12 is measured and sampled, August 12, Figure 6. Sockeye # 18 is tagged with motion sensitive MAP tags, August 14, Figure 7. Number of sockeye returned to the Alouette Watershed in 2009, by date....7 Figure 8. Fork length measurements of 15 sockeye returning to the Alouette Watershed in Figure 9. Number of sockeye returned to the Alouette Watershed in 2008 and 2009, by date....9 Figure 10. Fork length of sockeye returning in 2008 and List of Tables Table 1. Estimated number of smolts leaving the Alouette Reservoir during the spring surface release, (Matthews and Bocking, 2010)...3 Table 2. Number of returned adults sockeye to the Alouette Watershed, Table 3. Alouette adult sockeye age structure analysis, January

5 Introduction During the 2006 review of the Alouette Water Use Plan (WUP), the consultative committee (CC) identified the restoration of an anadromous sockeye salmon run as a key issue in the Alouette River system. The construction of the dam in the 1920s impounded the reservoir and extirpated the sockeye run soon after. As a means of re-establishing the stock, a spring surface release from the dam was integrated into the WUP. The release of 3m 3 s -1 from April to June will facilitate kokanee/sockeye out-migration from the reservoir. Since 2005, smolts have successfully migrated through the spillway gate during the spring release and to the ocean via the Alouette River (Table 1, Matthews and Bocking, 2010). Table 1. Estimated number of smolts leaving the Alouette Reservoir during the spring surface release, (Matthews and Bocking, 2010) Year of Smolt Migration Estimated Number of Smolts , , , , ,287 The viability and authenticity of kokanee smolt re-anadromization is dependent on the stocks ability to adapt to salt water conditions, to adopt behavioural strategies to compete and avoid predation in an ocean environment and to recognize and return to their native lake/stream system to spawn. Through the Adult Sockeye Enumeration monitoring program, sockeye that return to the Alouette River are collected, counted, genetically tested and released into Alouette Lake. The first run of Alouette sockeye salmon since extirpation were trapped by the program in 2007 and genetically proven to be Alouette stock. Objectives The main purpose of the Adult Sockeye Enumeration monitoring program is to establish whether out-migrating Alouette Lake kokanee/sockeye smolts are capable of adapting to an anadromous existence. Adaptation is considered successful when sockeye return from the ocean environment to spawn in Alouette Lake. Additionally, the monitoring program seeks to establish the timing and genetic structure of the returning sockeye run. The Allco Hatchery fish fence is operated from April to December every year to determine the timing and volume of the run and tissue samples are collected in order to ensure that returning adults are Alouette stock and not strays from other nearby coastal systems. Study Area The South Alouette Watershed (144 km 2 ), comprised of the South Alouette River and Alouette Reservoir, is located within the communities of Maple Ridge and Pitt Meadows (Figure 1). The site of the Alouette adult sockeye enumeration program is approximately 8 km downstream from the reservoir at the Allco Fish Hatchery operated by BC Corrections Fraser Regional January

6 Correctional Centre. The hatchery is appropriately positioned to intercept all migrating adult sockeye on their way back to the reservoir. Figure 1. Map of the Alouette Watershed Methods The monitor necessitates longer operation of the Allco Fish Hatchery brood stock collection fence and trap (Figure 2). From the first year of monitoring in 2008, the adult sockeye run appeared to be a summer run, arriving in the Alouette Watershed in July and August (Balcke, 2009). Taking this into consideration, as well as the maintenance requirements, and downstream steelhead kelt passage, the Alouette Monitoring Committee decided that in both the 2009 and 2010 extended trapping years the fence will be in operation between April and December. In 2009, the monitor began on April 15 th, January

7 Figure 2. The Allco Fish Hatchery fence and trap, July 2008 The fish fence is designed to direct sockeye and other salmon into the trap, which is monitored daily by BC Corrections staff and crew. Once trapped, the sockeye are dip netted out of the trap and transported by BC Corrections to Alouette Lake, where they were released. The sockeye are transported to the reservoir in specifically designed tanks fitted for both the Allco hatchery truck and sockeye transport trailer (Figure 3). At the lake, a slide is connected to the tanks and the sockeye are released (Figure 4). Figure 3. Sockeye transport tanks, August 2009 Figure 4. Sockeye transport tank with release slide connected, January 2010 January

8 For each returning sockeye, the date of capture and release was recorded. Additionally, fork length measurements, pictures and scale and tissue samples were taken for 15 sockeye collected beginning July 29, 2009 (Figure 5). The tissue samples were sent to the Pacific Biological Station laboratories in Nanaimo, BC for genetic analysis. These 15 returning sockeye were also tagged by LGL Limited with motion sensitive MAP tags, which were used to track the sockeye migration in the Alouette reservoir (Figure 6). Figure 5. Sockeye # 12 is measured and sampled, August 12, 2009 Figure 6. Sockeye # 18 is tagged with motion sensitive MAP tags, August 14, 2009 Results Adult Sockeye Returns A total of 45 sockeye returned to the Alouette Watershed during the 2009 run (Table 2). All were caught at the Allco trap and 43 were released live into the Alouette Reservoir. The two adult sockeye caught but not released into the reservoir were caught in the afternoon and were going to January

9 be tagged and released the following day. The next day, the sockeye were no longer in the trap and it was suspected that they were taken by river otters. Table 2. Number of returned adults sockeye to the Alouette Watershed, Year of Adult Return Number of Returned Adults Number of Adults Released Alive into Alouette Reservoir The first sockeye was caught in the trap on June 27 th and the last one of the 2009 run on October 19 th (Figure 4). The peak of the return was August th, with 5 sockeye being caught in the trap on the 12 th, 13 th and 15 th and 7 on the 14 th of August. Figure 7. Number of sockeye returned to the Alouette Watershed in 2009, by date. Survival The complex age structure of the returning Alouette sockeye stock means that survival for only the 2005 and 2006 smolts years has been estimated. The survival calculated by Bocking (unpublished data) is based on smolt to Total Return to Spawn (TRS) and was found to be % and 0.75 %, respectively for the 2005 and 2006 smolt years. January

10 Fork length As outlined in the methods, fork length measurements and tissue samples were only collected for 15 of the 45 returning sockeye. The length ranged from cm (Figure 8). Figure 8. Fork length measurements of 15 sockeye returning to the Alouette Watershed in 2009 Age Structure Scale samples were analyzed from 11 sockeye to determine the 2009 run age structure. Of the 11, two age classes were identified. There were seven sockeye classed as 4.2 and four as 5.3 (S. Latham, Pacific Salmon Commission, unpublished data). Thereby indicating that returning sockeye ranged between four and five years olds and spend two years in fresh water and either two or three years in a marine environment. Genetic sampling Genetic testing was completed for 15 of the 2009 returning adult sockeye and 97 of the 2009 outmigrating smolts. The results indicated that both the adult and juvenile samples are 100% Alouette stock (Candy, 2010). The two late returns were not sampled therefore their origin cannot be confirmed. Discussion Adult Sockeye Returns The 2009 Alouette Sockeye run continues to demonstrate timing comparable to that of a summer run, arriving in the Alouette Watershed in July and August. There were however two late returns in late-september and mid-october (Figure 9). The run in general was much lower than expected, as was the Fraser sockeye salmon run, which is in a low productivity period and had one of the lowest returns in 50 years (K.Benner, Department of Fisheries and Ocean, Personal Communication, January 15, 2010). Marine survival (smolt to Total Adult Return) for the 2009 January

11 Chilko sockeye run was estimated to be 0.3%, which is considerably lower than the long term average of 8.5% (M. Lapointe, Pacific Salmon Commission, Personal Communication, April 07, 2010). While this value is not directly comparable to the 0.532% (2005) and 0.75% (2006) Alouette survival estimates given the stock being removed by the fisheries is also considered, the Chilko values provide an indication of the low returns observed. Figure 9. Number of sockeye returned to the Alouette Watershed in 2008 and 2009, by date. Fork Length and Age Structure Measurements and scale samples were only collected for 15 of the 2009 returning sockeye. The sample size was significantly lower than the previous year in which all sockeye caught at the Allco trap were sampled. Last year the committee found that handling, during the measurements and weighing, placed too much stress on the fish and advised that the number sampled be reduced. The fork lengths measured in 2009 were similar to that of 2009 with 60 cm being the most predominant (Figure 10). January

12 14 12 Number of Sockeye Sockeye (54) 2009 Sockeye (15) Fork Length (cm) Figure 10. Fork length of sockeye returning in 2008 and 2009 The age class analysis completed by the Pacific Salmon Commission (S. Latham, unpublished data) in 2008 and 2009 showed that the returning sockeye salmon are fairly evening distributed between 4.2 and 5.3 age classes (Table 3). Table 3. Alouette adult sockeye age structure analysis, Date (Total Age Class Sampled) (53) 19(36%) 1(2%) 14(26%) 19(36%) 2009 (11) 7(63%) 0 0 4(36%) Genetic Analysis The genetic sampling from 2008 found that there was a significant variation between Alouette sockeye adults and sockeye from neighbouring systems, such as Coquitlam, Cultus, Harrison, and Weaver. The 2008 sockeye run did not include any stray sockeye from other systems, however the same cannot be definitively stated for the 2009 run as only 15 adult sockeye were sampled (Candy, 2009 as quoted in Bakcke, 2009; Candy, 2010; Mathews, 2009; Appendix B). Recommendations During the 2009 Alouette adult sockeye enumeration, there appeared to be some confusion as to the number of sockeye that should be measured, weighted, and tissue sampled. It is therefore recommended that the Alouette Monitoring Committee confirm an appropriate adult sockeye sample size and procedure for the 2010 study year. Acknowledgements This monitor was a part of the Alouette Project Water Use Plan funded by BC Hydro and overseen by the Alouette Monitoring Committee (AMC). Committee members include: Alouette January

13 River Management Society (ARMS), BC Corrections Allco Fish Hatchery, BC Hydro, Department of Fisheries and Oceans, District of Maple Ridge, Katzie First Nations, LGL Limited and Ministry of the Environment. Appreciation is extended to the following individuals: Geoff Clayton and Gerry Miller with ARMS; Ron MacLean, Mike Ilaender, Kelly Klassen and Dave Spann with BC Corrections Allco Fish Hatchery; Dave Hunter, James Bruce and Brent Wilson with BC Hydro; Maurice Coulter-Boisvert and Matt Foy with Fisheries and Oceans Canada; Mike Leon, Debbie Miller and George Moody with Katzie First Nations; Bob Bocking and Megan Matthews with LGL Limited; Greg Wilson, Shannon Harris and Emma-Jane Johnson with Ministry of the Environment; John Candy with Pacific Biological Station; Steve Latham with the Pacific Salmon Commission; Keri Benner with the Department of Fisheries and Oceans Canada; and Michael Lapointe with the Pacific Salmon Commission. References Balcke, A. (2009, March). Alouette Adult Sockeye Enumeration: Alouette River Management Society: Maple Ridge, BC. Bocking, R.C. (2009). Alouette Sockeye Brood Survivals [Unpublished data]. LGL Limited, Sidney, B.C. Candy, J.R. (2010, January). Genetic Structure of Alouette-Coquitlam Kokanee-Sockeye Salmon [Unpublished data]. Molecular Genetics Lab, Pacific Biological Station, DFO, Nanaimo, B.C. Mathews, M.A. and R.C. Bocking. (2010). Evaluation of the migration success of O. nerka (Kokanee / Sockeye) from the Alouette Reservoir, Report prepared for BC Hydro. Report prepared by LGL Limited, Sidney, B.C. (In draft) Mathews, M.A. (2009, December 23). RE: PBS genetic sampling for Alouette sockeye smolts to Dave Hunter. January

14 Appendix A: Sockeye sampling data, 2009 Fish No. Location Caught Date Caught Date Released Fork Length (cm) 1 Allco Fish Trap June June Allco Fish Trap July July Allco Fish Trap July July Allco Fish Trap July July Allco Fish Trap July * 6 Allco Fish Trap July * 7 Allco Fish Trap July July Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap August August Allco Fish Trap September September Allco Fish Trap September September Allco Fish Trap October October January

15 Appendix B: Data on Genetic Structure of Alouette out-migrating sockeye smolts and returning sockeye adults (Candy, 2010) Returning adults Smolts 15(0) 97(0) Code Region1 Estimate SD Estimate SD 1 Early Stuart 0.0 (2.1) 0.0 (0.4) 2 Pitt 0.0 (1.0) 0.0 (0.1) 3 Chilliwack 0.0 (0.7) 0.0 (0.1) 4 Early Misc. 0.0 (2.0) 0.0 (0.4) 5 Early Shuswap 0.0 (2.1) 0.0 (0.2) 6 Chilko 0.0 (1.2) 0.0 (0.2) 7 Horsefly 0.0 (1.6) 0.0 (0.3) 8 Mitchell 0.0 (1.1) 0.0 (0.1) 9 Late Stuart 0.0 (1.7) 0.0 (0.3) 10 Stellako 0.0 (0.9) 0.0 (0.2) 11 Birkenhead/Big Silver 0.0 (1.6) 0.0 (0.2) 12 Late Shuswap/Portage 0.0 (1.6) 0.0 (0.3) 13 Weaver/Cultus 0.0 (1.2) 0.0 (0.2) 14 Harrison/Widgeon 0.0 (1.0) 0.0 (0.1) 15 Kokanee Alouette (5.9) (1.0) 16 Kokanee Coquitlam 0.0 (0.6) 0.0 (0.1) 17 Other kokanee 0.0 (2.3) 0.0 (0.4) From: Megan Mathews [mailto:mmathews@lgl.com] Sent: 2009, December 23 2:29 PM To: Hunter, Dave J. Cc: bob Bocking Subject: Fwd: RE: PBS genetic sampling for Alouette sockeye smolts Hi Dave, Attached are the results for the Alouette genetic analysis (2009 smolt and adult). I spoke about the results briefly with John Candy and he explained that the results indicate both the juvenile and adult samples are 100% Alouette stock (run with the mixed Fraser baseline stocks). I'm not sure if you were looking for more, if you wanted analysis matching the adults and corresponding juveniles there are different tests that can be done to match individual alleles of smolts and adults to determine relations but may be constrained by the small sample size of the adults. If you would like to explore this we can talk further with John for some clarification, just wanted to pass on the info. As this is not included in our report I assume ARMS will be including this in their adult report and hence you will forward on to Amanda? As I mentioned I'll be out of the office now until February 3. If you need anything before this Bob will be able to help. Thanks Dave and have a great Christmas! Megan January