LATE FALL FISHERIES INVESTIGATIONS IN DIVERSION CANALS OF SOUTHERN ALBERTA, 2007

Transcription

1 LATE FALL FISHERIES INVESTIGATIONS IN DIVERSION CANALS OF SOUTHERN ALBERTA, 27 Prepared by: K. Dick and B. Meagher November, 27

2 Acknowledgments Trout Unlimited Canada (TUC) would like to acknowledge Alberta Environment (AENV) for their continued involvement with the Fish Rescue effort, with a special thanks to J. Mahoney and M. Bryski. TUC would also like to thank Alberta Sustainable Resource Development (ASRD) biologists; C. Wallman, D. Wig, J. Stelfox and T. Clayton for providing the necessary fish research licenses. We would also like to thank the AENV operators and technicians from the Vulcan-Arrowood Shop, Monarch Shop and the Bow Region who graciously assisted in transportation and release of the captured fish. TUC would like to thank the primary sponsors of the 27 Fish Rescue: Alberta Environment Alberta Conservation Association Tim Hortons s Coffee McCain Foods Navajo Metals We would also like to thank all other commercial and private contributors. Thank you to the Nelson family of the M.D. of Foothills and to the Wells and Jensen families of the M.D. of Cardston for granting permission to access the Women s Coulee Diversion and Mountain View Leavitt Aetna Headworks Canal respectfully. Finally, Trout Unlimited Canada and staff would like to extend their appreciation to all of the volunteers (both groups and individuals) for selflessly donating their time and support throughout the course of the 27 Fish Rescue. The following Trout Unlimited Canada staff participated in this project: B. Meagher Alberta Biologist K. Dick Fisheries Technician L. Skinner Fisheries Technician A. Beausoleil Fisheries Technician J. MacLeod Fisheries Technician Trout Unlimited Canada i

3 Executive Summary The Fish Rescue Program has been developed in response to growing concerns about fish losses in the irrigation canals of Southern Alberta. Trout Unlimited Canada, along with numerous volunteers, corporate and private donors has played a major role in the continued success of this ongoing project. The main objective of the Fish Rescue is to capture as many entrained fish as possible from irrigation canals during seasonal shutdown and transport them back to their original river systems. Alberta Environment owns and operates many diversion canals across the province, including the six canals TUC visited in 27. Locations visited in 27 included Women s Coulee Diversion (WCD), Western Headworks Canal (WHC), Carseland Bow River Headworks Canal (CBRHC), Mountain View Leavitt Aetna Headworks Canal (MVLAHC), Lethbridge Northern Headworks Canal (LNHC) and the Waterton Reservoir to Belly River Diversion Canal (WBD). The Fish Rescue has developed into a continuous scientific study investigating species composition and abundance of fish trapped in various irrigation canals. Data has now been collected since the initial rescue completed in Field techniques have remained fairly consistent throughout the duration of this study and have followed established protocol outlined from previous years (Meagher 2, Peterson et al. 26). Sampling methods consist of backpack electrofishing, seine netting and dip netting. The 27 rescue took place over 11 days and contribution from volunteers totaling 178 hours. Sampling consisted of: revisiting annual sampling sites and replicating techniques used in 26, 2 and 24; documenting fish abundance, species composition, and size distribution at each site; and recording fish mortality rates due to capture and release. The report consists of: maps of reaches sampled for each canal system; methods used in the field and for data analysis; results from data collection and discussion of the analysis; data comparisons between 27 and past Fish Rescue efforts; summary of the monetary value of the 27 Fish Rescue; and recommendations for future rescue efforts. Fish Rescue efforts in 27 resulted in the capture of 39,961 fish from the six irrigation canals investigated. The total number of fish captured in 27 is down from the 6,36 captured in 26 (Peterson et al. 27) but up from the 24,798 collected in 2 (Meagher 26). A total of 22 species were found throughout WCD, WHC, CBRHC, MVLAHC, LNHC and WBD. Rare finds included a suspected hybrid between a rainbow trout and a cutthroat trout (CRTR) and a shorthead redhorse (SHRD) discovered in LNHC. Total catch-per-unit-effort (CPUE) in 27 was down from 26 (Peterson et al. 27), yet the sportfish CPUE increased indicating a higher percentage of sportfish captured. Trout Unlimited Canada ii

4 However, this was not the case for WHC, as the lowest percentage of sportfish were collected here in 27 as compared to other years sampled. Mortalities resulting from the 27 effort were the highest they had been since new techniques were undertaken in order to reduce electroshocking related mortalities in 2 (Meagher 26). The increase in mortality was deemed to be transport related and less likely from the process of electroshocking. In comparison to the 39,961 fish rescued in 27, the 368 mortalities observed remains proportionately low (<1.% of total fish catch). Fish rescued from these irrigation canals is variable from year to year, measures need to be taken to reduce or eliminate fish entrainment. The 88,169 fish that have been captured and returned to local waterbodies from these canals since 1998 would have been lost without the Fish Rescue program. It is important to note that only six out of the thirteen canals that exist is Southern Alberta are investigated by the Fish Rescue program, and only small portions of each of these canals systems are investigated. Trout Unlimited Canada iii

5 Table of Contents Page # ACKNOWLEDGMENTS EXECUTIVE SUMMARY TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF TABLES IN APPENDIX A LIST OF TABLES IN APPENDIX B LIST OF APPENDIX C THROUGH H i ii iv vi viii ix ix ix 1. INTRODUCTION 1.1 BACKGROUND OBJECTIVES STUDY AREA Overview Women s Coulee Diversion Western Headworks Canal Carseland Bow River Headworks Canal Mountain View Leavitt Aetna Headworks Canal Lethbridge Northern Headworks Canal Waterton Belly Diversion 2. METHODS 2.1 SITE LOCATIONS AND SAMPLE DATES RELATIVE TO CANAL 13 DEWATERING 2.2 SAMPLING METHODS Electrofishing Use of Block Nets and Other Additional Efforts During 14 Electrofishing Surveys 2.3 ALTERNATE SAMPLING METHODS Seine Netting FISH PROCESSING Mountain Whitefish Sub-Sampling Mortality Rates 1 Trout Unlimited Canada iv

6 2. DATA ANALYSIS Fork Length Frequency Distributions Percentage of Fish Measuring 2 mm FL Catch Comparisons VOLUNTEER SUPPORT RESULTS 3.1 GENERAL Species Composition Species Distribution Catch-Per-Unit-Effort Mountain Whitefish Sub-Sampling Mortalities WOMEN S COULEE DIVERSION Species Composition Length Distribution WESTERN HEADWORK CANAL Species Composition Length Distribution CARSELAND BOW RIVER HEADWORKS CANAL Species Composition Length Distribution MOUNTAIN VIEW LEAVITT AETNA HEADWORKS CANAL Species Composition Length Distribution LETHBRIDGE NORTHERN HEADWORKS CANAL Species Composition Length Distribution WATERTON BELLY DIVERSION Species Composition Length Distribution VOLUNTEER SUPPORT AND PROJECT VALUE 2 4. DISCUSSION 4.1 GENERAL Absence/Presence, Composition, and Fork Length Comparisons 4.2 WOMEN S COULEE DIVERSION WESTERN HEADWORKS CANAL 2 Trout Unlimited Canada v

7 4.4 CARSELAND BOW RIVER HEADWORKS CANAL 2 4. MOUNTAIN VIEW LEAVITT AETNA HEADWORKS CANAL LETHBRIDGE NORTHERN HEADWORKS CANAL WATERTON BELLY DIVERSION OVERVIEW AND RECOMMENDATIONS. LITERATURE CITED 69 APPENDIX A Table A-1 and Table A-2 APPENDIX B Table B-1 and Table B-2 APPENDIX C Women s Coulee Diversion Fish Data APPENDIX D Western Headworks Canal Fish Data APPENDIX E Carseland Bow River Headworks Canal Fish Data APPENDIX F Mountain View Leavitt Aetna Headworks Canal Fish Data APPENDIX G Lethbridge Northern Headworks Canal Fish Data APPENDIX H Waterton Belly Diversion List of Tables Page # Table 1. Abbreviations, common names and scientific names 17 of all captured fish species. Table 2. Species composition of fish captured from each 26 diversion during the 27 Fish Rescue. Table 3. Catch-per-unit-effort (CPUE) results from all six 27 diversions in 27. Table 4. Mean fork lengths of sub-sampled mountain whitefish populations 27 at each diversion. Table. Species composition of fish sampled at Women s 28 Coulee Diversion in 27. Table 6. Percentage of species captured at Women s Coulee 28 Diversion (WCD) in 27 that measured 2 mm FL Table 7. Species composition of fish sampled at Western 29 Headworks Canal (WHC) in 27. Table 8. Percentage of species captured at Western Headworks 29 Canal (WHC) in 27 that measured 2 mm FL. Trout Unlimited Canada vi

8 Table 9. Species composition of fish sampled at Carseland 3 Bow River Headworks Canal (CBRHC) in 27. Table. Percentage of species captured at Carseland Bow River 3 Headworks Canal in 27 that measured 2 mm FL. Table 11. Species composition of fish sampled at Mountain View 31 Leavitt Aetna Headworks Canal (MVLAHC) in 27. Table 12. Percentage of species captured at Mountain View Leavitt Aetna 31 Headworks Canal (MNLAHC) in 27 that measured 2 mm FL. Table 13. Species composition of fish sampled at Lethbridge Northern 32 Headworks Canal (LNHC) in 27. Table 14. Percentage of species captured at Lethbridge Northern 33 Headworks Canal (LNHC) in 27 that measured 2 mm FL. Table 1. Species composition of fish sampled at Waterton Belly 34 Diversion (WBD) in 27. Table 16. Percentage of species captured at Waterton Belly Diversion 3 (WBD) in 27 that measured 2 mm FL. Table 17. Volunteer effort committed during the 27 Fish Rescue. 36 Table 18. Absence/presence comparisons between Nelson and Paetz 7 (1992), stranded fish captured during the 27 Fish Rescue and past sampling programs conducted in the same diversion canals. Table 19. Sportfish content of Trout Unlimited Canada Fish Rescues within 8 the WHC, WCD, CBRHC, MVLAHC, and LNHC from 1998 to 24. Table 2. Percentage of total fish measuring 2 mm FL by diversion and 8 by year. Table 21. The number of fish recovered during recent Trout Unlimited 9 Canada Fish Rescues. Table 22. Fish size class and density comparisons between years at WCD. 6 Table 23. Percentage of sportfish within annual total catch at WHC 1 61 during Table 24. Fish size class and density comparisons between years at WHC Table 2. Species composition comparisons between years within all sampled 63 sections of the CBRHC. Table 26. Fish size class and density comparisons between years at 64 CBRHC within the top 2 km of the canal only. Table 27. Fish size class and density comparisons between years at MVLAHC. 6 Table 28. Fish size class and density comparisons between years at LNHC. 66 Trout Unlimited Canada vii

9 Table 29. Fish size class and density comparisons between years at WBD. 67 List of Figures Page # Figure 1. Overview of the 27 Fish Rescue sample area. 6 Figure 2. Reach sampled in the Women s Coulee Diversion (WCD) 7 on September 29, 27. Figure 3. Reach sampled in the Western Headworks Canal (WHC) 8 on September 3, 27. Figure 4. Reaches sampled in Carseland Bow River Headworks 9 Canal (CBRHC) on October 3 rd and 4 th, 27. Figure. Reach sampled in Mountain View Leavitt Aetna Headworks Canal on October 12 th, 27. Figure 6. Reaches sampled in the Lethbridge Northern Headworks 11 Canal on October 13 th, 14 th,1 th and 16 th, 27. Figure 7. Reaches sampled in Waterton-Belly Diversion (WBD) on 12 October 26 th and 27 th, 27. Figure 8a. Fish identification key designed for volunteer use during 18 Trout Unlimited Canada Fish Rescues. Figure 8b. Page 2 of a fish identification key designed for volunteer use 19 during Trout Unlimited Canada s Fish Rescues. Figure 9. Fork length frequency distribution for rainbow trout 37 captured in the Women s Coulee Diversion, Figure. Fork length frequency distribution for mountain whitefish 38 captured in the Women s Coulee Diversion, Figure 11. Fork length frequency distribution for rainbow trout 39 captured in the Western Headworks Canal, Figure 12. Fork length frequency distribution for brown trout 2mm 4 (FL) captured in Women s Coulee Diversion, Figure 13. Fork length frequency distribution for rainbow trout captured 41 in the Carseland Bow River Headworks Canal, Figure 14. Fork length frequency distributions for brown trout captured 42 in the Carseland Bow River Headworks Canal, Figure 1. Fork length frequency distributions for mountain whitefish 43 2 mm (FL) captured in the Carseland Bow River Headworks Canal, Figure 16. Fork length frequency distribution for rainbow trout captured in 44 the Mountain View Leavitt Aetna Headworks Canal, Trout Unlimited Canada viii

10 Figure 17. Fork length frequency distribution for rainbow trout captured in 4 the Lethbridge Northern Headworks Canal, Figure 18.. Fork length frequency distribution for brown trout captured in 46 the Lethbridge Northern Headworks Canal, Figure 19. Fork length frequency distributions for mountain whitefish 47 2 mm (FL) captured in the Lethbridge Northern Headworks Canal, Figure 2. Fork length frequency distributions for brown trout captured 48 in the Waterton Belly Diversion, Figure 21. Fork length frequency distributions for mountain whitefish 49 2 mm (FL) captured in the Waterton Belly Diversion, Figure 22. Species comparisons caught during fish rescues, List of Tables in Appendix A Page # Table A - 1. The Terms of Reference of contract #8WM Table A - 2. Project revenue/expenditures of the 27 Fish Rescue. 2 List of Tables in Appendix B Page # Table B - 1. Sample reaches, dates and capture effort in the 1 respective diversion canals from September 29 th through October 27 th, 27. Table B - 2. Fish species captured at each sample site during the Fish Rescue. List of Appendix C through H Appendix C - Life history data collected during sampling at the WCD on Sep. 29 th, 7 Appendix D - Life history data collected during sampling at the WHC on Sep. 3 th, 7 Appendix E - Life history data collected during sampling at the CBRHC on Oct. 3 rd & 4 th, 7 Appendix F - Life history data collected during sampling at the MVLAHC on Oct. 12 th, 7 Appendix G - Life history data collected during sampling at the LNHC on Oct. 13 th -16 th, 7 Appendix H - Life history data collected during sampling at the WBD on Oct. 26 th & 27 th, 7 Trout Unlimited Canada ix

11 1. Introduction 1.1 Background Southern Alberta s farm and rangelands largely depend on supplies of water diverted from the Bow, Highwood, Oldman, St. Mary, Waterton and Belly river systems. The water diverted from these systems is delivered through various irrigation canals from spring until late fall, when dewatering of these canals occurs. The canals are required in Southern Alberta to supply the 1,344,316 acres of land that depend on irrigation water (Alberta Agriculture and Food, 26) in a semi-arid climate that drastically increases the likelihood of drought. Although favorable for farmers, these canal systems can be deadly for the fish that enter them. Fish can move into the canals from the time the headgates open in early spring until they are closed in late fall. Once fish are in the canal they are unable to return, freely to their original systems. Later, upon canal dewatering, all fish trapped in these canals subsequently die. Trout Unlimited Canada (TUC), Alberta Environment (AENV) and volunteers focus their rescue efforts on 6 of the 13 canals that currently exist in Southern Alberta. Trout Unlimited Canada s main objective through this project is to rescue as many fish as possible and transport fish entrained in these canals back to their original river systems. TUC s Fish Rescue program has developed into a continuous scientific study, collecting information on species composition and abundance of fish captured from various irrigation canals. It has also developed into a valuable educational tool to work with local students from all levels. Volunteers are able to learn about these river systems with educational hands-on experience. The ongoing nature of this study makes it a unique and informative fisheries investigation. Collection methods have been fairly consistent throughout the duration of this investigation (RL&L 1999, 2, 21; Eisler and Brewin 22; Eisler et al. 23; Eisler 24; Meagher 2, 26; Peterson et al. 27). Information collected each year is compared to baseline data from previous Fish Rescues and earlier pertinent studies (Luoma and Bietz 1987; Barton and Egan 1992; Helwig and Fernet 1993; Fernet and Bjornson 1994; and Fox et al. 1996). Electroshocking has become the predominant method of capture, although seine nets are being used more in areas where electroshocking related mortalities are high. The 27 Fish Rescue fieldwork took place over a total of 11 days. Data collection occurred along the Women s Coulee Diversion (WCD), Western Headworks Canal (WHC), Carseland Bow River Headworks Canal (CBRHC), Mountain View Leavitt Aetna Headworks Canal (MVLAHC), Lethbridge Northern Headworks Canal (LNHC) and Waterton Belly Diversion (WBD). 1.2 Objectives Overall objectives: Replicate past Fish Rescue investigations within WCD, WHC, CBRHC, MVLAHC, LNHC, and WBD; and Trout Unlimited Canada 1

12 Capture entrained fish from diversion canals for release into suitable main-stem river systems. 27 Fish Rescue goals: Apply consistent methods and annual investigations within each diversion canal; Collect data concerning species composition and abundance, and compare to data collected from previous years; Complete a scientific paper for Alberta Environment discussing results from the 27 Fish Rescue and recommendations for the 28 Fish Rescue; Raise awareness and provide education regarding fish biology and conservation in Alberta; Promote public involvement in the Fish Rescue program; Rescue as many fish as possible; and Minimize preventable fish mortalities during the rescue effort. 1.3 Study Area Overview The Fish Rescue program focuses on six diversion canals, all of which are owned and managed by Alberta Environment. Figure 1 shows an overview of the Fish Rescue study area and Figure 2 through Figure 7 show each diversion independently and the specific reaches sampled. Flow of water into a canal is terminated by the closure of the headgate structure. The volume of water and flow rate affect the closure rate (Eisler 24). Once the gates have closed, dewatering of the canal takes place, forcing fish to congregate into pools along the canal providing a sufficient volume of water and necessary oxygen for survival. Larger canals may hold water for several weeks, while smaller diversions drain more rapidly. These small pools provide refuge for a short while, but are at risk of oxygen depletion, freezing and evaporation. Time restrictions and weather conditions can greatly influence the success of the fish rescue; proper planning is a necessity. Sampling sites have been established at specific structures within the canals. Structures such as headgates, check structures, drop structures and bridges tend to hold water for the longest period of time. Subsequently, fish concentrate here as dewatering occurs. The Fish Rescue takes place at the stage of dewatering that facilitates the most efficient and effective capture of fish. Focusing on the selected sampling sections, rather than the entire canal is not only effective but provides annual consistency for the study. Replicating annual investigations and methods ensures comparable data from year to year. Unfortunately it is not feasible to investigate the entire canal to remove all fish entrained. Trout Unlimited Canada 2

13 1.3.2 Women s Coulee Diversion (WCD) The WCD is located about nine kilometers west of the Town of High River (Figure 2). Water is diverted from the Highwood River into the canal via two headgate structures. The first gate acts as a primary structure, diverting water from the river into a side channel returning to the Highwood River. Fish can move freely from this channel back into the Highwood River, therefore a rescue at this site is not required. The secondary headgate structure diverts water from the primary channel into the irrigation canal, and is not fitted with an exclusion device to prevent fish from becoming entrained. WCD headgates opened May 1 st, 27 and were closed on September 29 th, 27. Fish rescue efforts commenced at 8:am on September 29 th and ended at :3pm that same day. Sampling at WCD began 2.7 Km downstream from the second headgate structure. The lower limit of the study area is located upstream of a culvert that cannot be accessed. In order to access the AENV service road along WCD, private property must be crossed. TUC received permission from the Nelson family so that staff and volunteers could gain access to the WCD processing area Western Headworks Canal (WHC) The WHC (Figure 3) stems from the Bow River within Calgary s city limits and eventually drains into Chestermere Lake approximately 2 Km southeast. The primary headgate structure is located near the Max Bell Arena located in Calgary, Alberta (parallel to Deerfoot Trail). Water is diverted into the canal via one headgate structure that is not fitted with any fish exclusion device. WHC headgates opened April 26 th, 27 and closed on September 3 th, 27. Fish rescue effort commenced at 8:am on September 3 th and ended at approximately 2:pm that same day. Sampling at WHC began 2m downstream from the headgate structure. The reach was sampled three times. WHC is accessed via a municipal bike/walking path. The City of Calgary Parks and Recreation Department provided TUC with a key for the gate located at the North end of the Max Bell parking lot. The processing area was set up in close proximity to the canal allowing for efficient processing of the fish. A supplemental section was completed collecting fish from a m reach above the blocking net. This area had not been sampled as such in the past and the data collected is recorded separately for the purposes of this report Carseland Bow River Headworks Canal (CBRHC) The CBRHC is located ~2 Km south from the community of Carseland (Figure 4.). Water is diverted from the Bow River at the Carseland Weir into the adjacent canal via one headgate structure that does not possess a fish exclusion device. The CBRHC conveys water approximately 6 Km southeast before draining into McGregor Lake. CBRHC headgates opened April 16 th, 27 and closed on Oct 2 nd, 27. Fish Rescue efforts commenced at 8:am on October 3 rd, 27 and ended at approximately 6:pm on October 4 th, 27. Trout Unlimited Canada 3

14 Sampling at CBRHC1 began 2m downstream of the headgate structure on October 3 rd, 27. This reach was electrofished a total of three times. At the end of the first day a seine net was used to push fish into CBRHC2 for the second day of sampling. The second day of sampling at CBRHC2 (another 2m section was sampled approximately 2 Km from the headgates) was completed with four passes of the section and an additional fourth pass in CBRHC1. CBRHC is accessed via an Alberta Environment service road that runs the length of the canal. Alberta Environment provided TUC with a key to access the service road Mountain View Leavitt Aetna Headworks Canal (MVLAHC The MVLAHC is located approximately Km southwest from the Village of Mountain View and 6 Km north from the United States border (Figure ). Water is diverted from the Belly River via one headgate structure, which is fitted with a fish exclusion device, and eventually drains Km downstream into Payne Lake Reservoir. The main channel continues for another 3 Km from Payne Lake Reservoir into the Aetna Irrigation District. MVLAHC headgates opened May 19 th, 27 and were closed on August 31 st, 27. Following this closure an initial smaller scale rescue effort by Alberta Environment ensued. TUC was not involved with this effort and therefore the dataset will not be included in these results. The gates were reopened September 17 th, 27, and then closed for the season on October 12 th, 27. The Fish Rescue effort commenced at 9:am of October 19 th, and was completed by 3:pm that same day. Sampling at MVLAHC started on the north side of the bridge approximately 2 Km downstream of the headgate structure. This reach was sampled with a one pass removal by electrofishing. The MVLAHC is accessed by an Alberta Environment service road that runs the length of this sampling reach. Private land must be crossed in order to access the service road. TUC received permission from the Jenson family so that staff and volunteers could gain access to MVLAHC Lethbridge Northern Headworks Canal (LNHC) LNHC flows between the communities of Brocket and Barons Alberta. Water is diverted from the Oldman River on the Peigan Reserve via one headgate structure that is not fitted with any fish exclusion device. The LNHC runs approximately 8 Km in a northeasterly direction before draining into Keho Lake. Members of the Peigan Nation along with Alberta Environment sampled a section of the canal located on the reserve land; data from this effort is not included in this report. North of the reserve, fish rescue efforts are focused towards check structures and bridges. LNHC headgates opened May 2 nd, 27 and closed on Oct 12 th, 27. Fish Rescue efforts commenced at 8:am on October 13 th, 27 and concluded three days later on Oct 16 th, 27. Fish were collected outside the usual study area as observed while driving along the canal in various isolated pools. These individuals were added to this report as supplemental catch. The sampling at LNHC began approximately 32 Km downstream from the headgate structure and completed at a check structure (LNHC 9) (Figure 6). The LNHC was accessed via an Alberta Environment service road that runs the length of the canal. This service road Trout Unlimited Canada 4

15 was accessed from one of many intersecting highways and municipal roads (Including Highway 2 and Hwy 23 and Secondary Highways 19, 811 and 78). Alberta Environment provided a key to access any locked gates located along the canal service road Waterton Belly Diversion (WBD) The WBD diverts water from the Waterton Reservoir via one headgate structure that is not fitted with any fish exclusion device. The WBD runs approximately 8 Km in an easterly direction before draining into the Belly River (Figure 7). WBD headgates opened April 21 st, 27, and then closed on October 13 th, 27. The Fish Rescue efforts commenced at 8:am on October 26 th, 27 and ended the next day at :pm. We attempted to enter the canal earlier in the month, but as the gates had not been closed as scheduled the effort had to wait until the canal was safe to enter. Sampling at WBD commenced at the headgate structure and was completed at the spillway structure approximately 8 Km down the canal. Rescue efforts were focused above and below several drop structures (WBD1 through WBD6) located throughout the canal (Figure 7). The WBD was accessed via an Alberta Environment service road the runs the length of the canal. This canal service road intersects Secondary Highway, and other secondary highways on its way to the spillway. Alberta Environment provided TUC with a key to the gate located at the east end of the canal. Trout Unlimited Canada

16 Saskatchewan Calgary WHC Chestermere Lake Bow River Highwood River High River WCD Little Bow River Women s Coulee Reservoir CBRHC McGregor Lake Travers Reservoir Mosquito Creek LNHC Keho Lake Oldman River Waterton River Waterton Reservoir Fort Macleod Belly River WBD Payne Lake MVLAHC Lethbridge United States - Natural waterway - Diversion canal - Approximate municipal boundary - Western Headworks Canal - Carseland Bow River Headworks Canal - Women s Coulee Diversion - Lethbridge Northern Headworks Canal - Waterton-Belly Diversion - Mountain View Leavitt Aetna Headworks Canal South Saskatchewan River British Columbia Figure 1. Overview of the 27 Fish Rescue study area. WHC CBRHC WCD LNHC WBD MVLAHC N 2 km Trout Unlimited Canada 6

17 N - Underground water tunnel Highwood River - Township gravel roads WCD Headgate Upper and lower limits of WCD 1 High River 7 m Women s Coulee Reservoir WCD Direction of flow Figure 2. Reach sampled in the Women s Coulee Diversion (WCD) on September 29th, 27. Trout Unlimited Canada 7

18 Chestermere Lake Memorial Drive Headgate Upper and lower limits of WHC 1 17th Avenue N Bow River - Bridge relevant to sample reaches Deerfoot Trail - Street/Avenue - Drop structure - Railway bridge 2 km Direction of flow WHC Figure 3. Reach sampled in the Western Headworks Canal (WHC) on September 3, 27. Twp. Rd 24 Trout Unlimited Canada 8

19 N Carseland Bow River Carseland Weir CBRHC Headgate Ponded Area Upper limit of CBRHC 1 - Lower limit of CBRH C 1 - CBRHC Direction of flow 24 - Bridge Structure - Approximate municipal limit m 24 - Highway - Weir Structure - Carseland-Wyndham Provincial Park Figure 4. Reaches sampled in the Carseland Bow River Headworks Canal (CBRHC) on October 3rd and 4th, 27. Trout Unlimited Canada 9

20 Mountain View N Payne Lake Lower limit of MVLAHC 1 Belly River MVLAHC Direction of flow - Drop structure - Highway - Local gravel road/private access 3 m MVLAHC Headgate and Upper limit of MVLAHC 1 Figure. Reach sampled in the Mountain View Leavitt Aetna Headworks Canal (MVLAHC) on October 12, 27. Trout Unlimited Canada

21 N 2 X LNHC 2 78 X X X LNHC 1 LNHC 3 Willow Creek X LNHC 4 LNHC 6 LNHC X X 19 LNHC 8 X X LNHC 7 (not sampled in 2) X Direction of flow X LNHC 9 X Oldman River Headgate Peigan Reserve m X km canal intervals - starting at km - Highway - Bridge relevant to sample section or access - Drop structure - Flume structure - Check structure - Reserve Boundary th th th Figure 6. Reaches sampled in the Lethbridge Northern Headworks Canal (LNHC) on October 13, 14, and 1, 27. Trout Unlimited Canada 11

22 Trout Unlimited Canada 12

23 2. Methods 2.1 Site Locations and Sample Dates Relative to Canal Dewatering Sampling sites selected in 27 were chosen to replicate past fisheries investigations at each canal. Supplementary sites were also sampled in sections of the canal where there was an apparent need for additional effort. Supplemental sites are considered purely a rescue and data collected during these efforts are not included in the inter-annual comparisons. Sampling locations visited in 27 included WCD, WHC, CBRHC, MVLAHC, LNHC and WBD. The main objective of the Fish Rescue program remains the same; safely remove as many fish as possible while collecting accurate data on species composition and abundance for each site. Rescue efforts, as mentioned earlier, must be coordinated with the closure of the canal. Therefore, AENV and TUC work together to organize a successful fish rescue. Final closure of the headgate structures in smaller canals such as, WCD, WHC, CBRHC and MVLAHC took place the first day of the Fish Rescue effort. In larger canals such as the LNHC and WBD, final closure must take place days prior to the rescue. All canals activities are ramped down prior to final closure to eliminate erosion and other technical issues. 2.2 Sampling Methods Sampling methods employed in 27 were duplicated (as close as possible) from previous years (i.e. Peterson et al. 27 and Meagher 26). Electrofishing is still the predominant method of capture, but under certain conditions this technique can be inefficient and result in increased mortalities. Therefore, dip nets and seine nets are utilized more frequently. This method results in reduced mortality rates of sensitive species including mountain whitefish (MNWH) and other larger sport species Electrofishing Certified TUC and AENV staff members operate backpack electrofishing units at all times. Crews consisted of one electroshocking unit, three or four dip netters and one bucket carrier; two crews were utilized simultaneously side by side for greater efficiently and improved coverage in larger canals. Electrofishing techniques and safety followed the guidelines set out by Alberta Fish and Wildlife (Kraft et al. 1982) and the Alberta Fisheries Management Division (Radford et al. 199). Catch-per-unit-effort (CPUE) was calculated by dividing the number of fish captured by the active electrofishing minutes at each canal and provided in Table Use of Block Nets and Other Additional Efforts during Electrofishing Survey Block nets were utilized to isolate fish into specific reaches of the canal for thorough removal. Once isolated, dip nets, seine nets and/or electrofishing were used independently or in conjunction to remove fish efficiently. Block nets were utilized at WHC, CBRHC, LNHC and WBD. In order to ensure the sampling reaches are consistent between years; markers in Trout Unlimited Canada 13

24 and along the canal help determine where the block nets have beeen placed. The block nets were placed horizontally across the main channel and anchored in place by several t-posts that had been pounded into the substrate. Numerous rocks can be then placed along the bottom, essentially anchoring the net in the substrate. The use of t-posts is limited in certain sections of canals. In areas where the canals are lined with impervious mats t-posts were replaced with Rubbermaid tubs that had been weighted down with rocks. The seine net is draped over the tubs providing the same blocking effect. Specific details describing the use of block nets and additional efforts for each specific canal can be found in Appendix B, Table B Alternate Sampling Methods Seine Netting Seine nets are constructed of 12 mm stretch diagonal netting, 1. m tall and vary in width between 17 m and 22 m. Staff members and volunteers wade down the canal (standing in 1 m increments) with a foot hooked into the bottom of the seine net, referred to as the lead line. The net is dragged a predetermined length of the canal corralling the fish into a desired area to facilitate efficient capture. Once the destination was reached the net is held in place or hung on t-posts. This technique employed in past rescue efforts (Eisler et al. 23; Meagher 2; Meagher 26; and Peterson et al. 27) was replicated in 27. A smaller seine net (a typical beach seine) utilizing 3 mm stretch diagonal netting, measuring 2 m tall and 3 m in width was also used in specific locations. This net required two individuals, one at each end. For details regarding the use of seine nets and specific locations refer to Appendix B, Table B Dip Netting Dip netting was used in conjunction with seining in confined areas where electrofishing could result in increased mortalities. Seine nets were utilized to trap fish in a confined area, the fish were then easily dip netted. Multiple passes were completed via this dip netting technique until the majority of the fish were removed (based on visual inspections). The sample reach would then be cleaned up with an electrofishing effort. 2.4 Fish Processing A guide to fish species common names, scientific names and abbreviations are provided in Table 1 (as described by Mackay et al. 199). Standard abbreviations were used when processing fish. All fish captured were identified to the species level and tallied for the purpose of this report. All sportfish, with the exception of some whitefish (MNWH/LKWH) and burbot (BURB), were measured and weighed, regardless of their size, as described by Peterson et al. (27). Trout Unlimited Canada 14

25 Eisler and Brewin (22) describe the complete count methodology utilized during past Fish Rescues. The complete count method ensures that all fish with fork lengths 2 mm are measured, weighed and identified to the species level. In 27, as in 26 (Peterson et al. 27), this methodology was followed where time permitted, but in some instances the volume of fish exceeded what could be processed safely without causing unnecessary mortalities. Under these circumstances fish were identified to species, measured for length, but not weighed. The benefit of this technique includes minimizing stress and returning fish back into the river system in a timely fashion, outweighing the need to collect all weights for this dataset Mountain Whitefish Sub-Sampling Routine sampling protocol has been to measure and weigh all sportfish regardless of size. Due to the often abundant juvenile MNWH (< 2 mm) populations, protocol was established to minimize stress resulting in a subsequent decrease in capture related mortalities. This protocol involves taking a random sub-sample of juvenile MNWH representing these age classes Mortality Rates Many factors contribute to capture and post-release mortalities during the Fish Rescue. Initial shock, temperature, low dissolved oxygen levels and stress during handing can lead to mortality. Therefore, one of the Fish Rescue s main goals is to develop ways to reduce capture-release mortalities. Mortalities that occurred in 27 where recorded during processing. Once processed, fish are held in an oxygenated water tank before being transported and released into the appropriate river system. Post-release mortalities are collected in areas where it is possible and total counts are estimated. Moralities are collected and are either given to the Birds of Prey Center in Lethbridge (as an additional food source) or The Royal Alberta Museum in Edmonton (where they would be added to the museums collection). 2. Data Analysis 2..1 Fork Length Frequency Distribution Fork length frequency distributions provide insight into age class divisions. They also display classes that are particularly susceptible to entrainment and lost due to entrainment. Graphs were created using Microsoft Excel and provide comparisons between like sections of canals from subsequent years (Figures 9 through 2) Percentage of Fish Measuring 2 mm Fork Length (FL) The percentage identifies the ratio of adult to juvenile fish collected in 27. The number of fish possessing fork lengths 2 mm was divided by the total number of fish captured for each species at each canal. Sportfish with fork lengths < 2 mm are assumed to be Trout Unlimited Canada 1

26 juveniles. Juveniles will not contribute to the overall reproductive success of the population this spawning season Catch Comparisons Every attempt is made each year to maintain effort at each site to ensure that comparison between years is consistent. Therefore in order to make valuable comparisons of total catch between years a catch-per-unit-effort (CPUE) can be calculated. CPUE is calculated by dividing the number of fish captured by the number of active electroshocking minutes (fish/min). CPUE was calculated for each canal, totaled and averaged. In 27 many extra supplemental sites were included due to necessity or availability of time. Data collected during supplemental sampling efforts is not included in the dataset used to compare with past sampling efforts. Supplemental sites are considered purely a rescue effort. In future rescue reports we may be able to directly compare between different supplement sites. 2.6 Volunteer Support The Fish Rescue of 27 would not have been possible without the help of enthusiastic school groups, families and individuals that graciously donated their time to help save these fish. The success of the Fish Rescue Program largely depends on volunteers support though their time and financial donations. This year, 297 volunteers participated during the 11 days in the field, together accumulating approximately 1,78 volunteer hours. Each field day volunteers registered and asked to sign a photo consent form. Once organized volunteers were prepared with a safety talk and program background information. Tasks included fish capture, fish identification, fish processing and data recording. Participants entering the water had to be over the age of 18 and be wearing non-breathable neoprene waders. TUC s provincial biologist B. Meagher took time each day to skillfully educate volunteers on fish identification, fish handling techniques and details about the fisheries investigations taking place. Copies of the fish identification key (Figures 8a and 8b) were on hand for the volunteers. TUC and AENV staff members were around at all times to supervise volunteers and answer any questions. Trout Unlimited Canada 16

27 Table 1. Abbreviations, common names and scientific names of all captured fish species. Abbreviation Common Name Scientific Name Sportfish RNTR rainbow trout Oncorhynchus mykiss BNTR brown trout Salmo trutta BLTR bull trout Salvelinus confluentus BKTR brook trout Salvelinus fontinalis LKWH lake whitefish Coregonus clupeaformis MNWH mountain whitefish Prosopium williamsoni BURB burbot Lota lota NRPK northern pike Esox lucius LKTR lake trout Salvelinus namaycush YLPR yellow perch Perca flavescens CTTR cutthroat trout Oncorhynchus clarki SAUG sauger Sander canadensis GOLD goldeye Hiodon alosoides MOON mooneye Hiodon tergisus LKST lake sturgeon Acipenser fulvescens Rafinesque ARGR Arctic grayling Thymallus arcticus WALL walleye Sander vitreus Non-Sportfish LNSC longnose sucker Catostomus catostomus WHSC white sucker Catostomus commersoni MNSC mountain sucker Catostomus platyrhynchus SHRD shorthead redhorse Moxostoma macrolepidotum SPSC spoonhead sculpin Cottus ricei BRST brook stickleback Culaea inconstans FTMN fathead minnow Pimephales promelas PRDC pearl dace Margariscus margarita LNDC longnose dace Rhinichthys cataractae NRDC northern redbelly dace Phoxinus eos LKCH lake chub Couesius plumbeus TRPR trout perch Percopsis omiscomaycus SPSH spottail shinner Notropis hudsonius EMSH emerald shinner Notropis atherinoides RVSH river shinner Notropis blennius Trout Unlimited Canada 17

28 Figure 8a. Page 1 of a fish identification key designed for volunteer use during Trout Unlimited Canada Fish Rescues. Trout Unlimited Canada 18

29 Salmon Family (have adipose fin) Small scales brown trout: black spots with pale haloes Large scales mountain whitefish: top of dorsal fin does not extend beyond back of fin when fin is flattened rainbow trout: black spots without pale haloes lake whitefish: Top of dorsal fin extends beyond back of fin when fin is flattened bull trout: no black spots on body or fins Minnow Family(no adipose fin) Sucker Family(have thick fleshy lips) longnose dace: tip of upper jaw extends well past lower jaw longnose sucker: scales increase in size from the head (smallest) to the caudal fin (largest) lake chub: first ray in dorsal fin is a full ray, barbels (small whiskers) present on each side of upper jaw white sucker: scales uniform in size across the body fathead minnow: first ray in dorsal fin is a half ray, black vertical line in front of caudal fin longnose sucker No notch notch mountain sucker Copyrights for images used in this pamphlet are held by Karl A. Geist (all salmonid illustrations), New York Department of conservation (longnose dace and lake chub), Don McPhail (longnose and white sucker) and Joseph Tomerelli (fathead minnow). The key on the other side was adapted from Fishes of Alberta, pgs. 79 & 88. Figure 8b. Page 2 of a fish identification key designed for volunteer use during Trout Unlimited Canada Fish Rescues. Trout Unlimited Canada 19

30 3. Results 3.1 General Species Composition During the Fish Rescue of 27 a total of 22 species of fish were captured, including a suspected hybrid between a rainbow trout and a cutthroat trout (CRTR), found at WCD. The number of fish rescued from the six diversion canals visited in 27 totaled 39,961 fish (Table 2). Of these 26.% or,89 individuals were sportfish species. The other 29,372 individuals, or 73.% were non-sportfish species. Mountain whitefish (MNWH) were the most abundant sportfish species captured in 27, accounting for 63.2% of all sportfish captured and 16.8% (n = 6,69) of the overall catch. Longnose dace (LNDC) were the most abundant non-sportfish species collected, representing.2% of non-sportfish captured and 36.9% (n = 14,748) of total fish collected (Table 2). MNWH dominated the sportfish catch in three of the six canals (89.8% in WCD (n = 1,823); 2.9% in CBRHC (n = 26); and 64.% in LNHC (3,883)). In the WHC very few sportfish were collected overall; the most common species captured was brown trout (BNTR) consisting of.% (n = 2) of total sportfish catch. In the MVLAHC and WBD burbot (BURB) accounted for 77.1% (n = 74) and 9.2% (n = 87) of total sportfish sampled respectively. Lake whitefish (LKWH) (n = 1,796) were the second most abundant sportfish species captured overall (17.% of total sportfish captured), but they were never the dominant sportfish collected from any one canal. Rainbow trout (RNTR) (n= 621) and brown trout (BNTR) (n = 47) accounted for.8% and 4.3% respectively, of the total sportfish sampled. Four additional game fish species were captured from one or more of the canals investigated in 27. In order of greatest abundance these include, northern pike (NRPK) (n = 124), bull trout (BLTR) (n = 7), brook trout (BKTR) (n = 3) and a suspected rainbow trout/cutthroat trout hybrid (CRTR) (n = 1). Together these four species totaled 1.3% (n = 13) of total sportfish catch (Table 2). Non-sportfish species were more abundant in every canal sampled in 27, with the exception of LNHC (66.8% in WCD; 99.% in WHC; 93.1% in CBRHC; 88.2% in MVLAHC; and 3.6% in WBD). LNDC dominated the non-sportfish captured at WCD and CBRHC accounting for 72.6% (n = 2,964) and 64.6% (n = 8,721) respectively. WHC catch was comprised predominantly of brook stickleback (BRST) (n = 2,97) and LNDC (n = 2,49), together totaling 77.1% of the non-game species collected at this site. In MVLAHC, lake chub (LKCH) was the dominate non-sportfish species (41.4% (n = 297)). LNHC effort produced longnose suckers (LNSC) and white suckers (WHSC) as the most common nonsport species, 33.4% (n = 836) and 28.7% (n = 717) respectively. The effort at WBD resulted in trout perch as the most abundant non-sport species collected with 893 individuals combining for 3.1% of the total non-sportfish catch. Trout Unlimited Canada 2

31 3.1.2 Species Distribution Distributions of the 22 species captured in 27 were generated using information collected from the six diversions investigated. RNTR and MNWH were the only two sportfish species found at all six diversions. Similarly, WHSC, LNDC and LKCH are non-sport species that were also found throughout all six systems. Other sport and non-sport fish species found in the majority of canal systems included BURB, LNSC, and spoonhead sculpins (SPSC). In contrast, sport and non-sport species such as BLTR, BKTR, NRPK, shorthead redhorse (SHRD), pearl dace (PRDC), spottail shinners (SPSH) and northern redbelly dace (NRDC) were all found in only a few canals in relatively small numbers. Complete descriptions of species distributions for 27 are provided in Appendix B, Table B Catch-Per-Unit-Effort Catch-per-unit-effort (CPUE) was calculated using only the electrofishing effort, even though LNHC is the only canal where a combination seining, dip netting and electrofishing were used in conjunction with one another to capture fish. In this case CPUE was calculated using only the fish that were collected via electroshocking, which accounted for 71.4% (n = 6,12) of total fish catch at LNHC. Total CPUE included all species of fish and was highly variable. Total CPUE ranged between 4.9 fish/min at MVLAHC to 32.2 fish/min at WHC and averaged 13. fish/minute for all effort. Sportfish CPUE ranged from.2 fish/minute (WHC) to. fish/min (LNHC) and averaged 2.9 fish/min for all effort (Table 3) Mountain Whitefish Sub-Sampling Mountain whitefish (MNWH) sub-sampling provides insight into population structure of juveniles (<2 mm) collected from the canals. During processing we sub-sampled individual whitefish < 2 mm selected at random. These individuals were then measured for fork length and weighed. Sample sizes in 27 range between 2 and individuals collected from the canals. MNWH mean fork length ranged between 94.2 mm to 13. mm at WCD and WBD respectively. The MNWH sub-sample fork length ranged between a low of 7 mm up to the limit of 199 mm (Table 4) Mortalities Capture and handling related mortalities occurring in 27 totaled 268 individuals. In comparison to total fish captured, mortalities that occurred in 27 represented only a small proportion of the fish rescued (.7% of total fish catch). Appendixes C though to H provide the specific locations where these individual species mortalities occurred. Trout Unlimited Canada 21

32 Transport and release related mortalities have not been recorded until 27. Approximately fish mortalities (.3 % of total fish catch) were observed at the release site on Oct 1 th, 27 at LNHC due to a combination of factors. 3.2 Women s Coulee Diversion Species Composition A total of thirteen species of fish were captured from WCD. Five of thirteen species were sportfish including a (suspected) hybrid between a rainbow trout and cutthroat trout (CRTR). The most abundant sportfish species found at this location was MNWH. MNWH captured from WCD accounted for 89.9% of game fish and 29.8% (n = 1,823) of total fish catch (Table ). RNTR were the second most common sportfish species collected, representing.% (n = 22) of sportfish and 3.3% of total catch. BLTR (n = 3) and BURB (n = 1) were also present but in relatively low numbers. Eight non-game fish were also captured at WCD. LNDC were the most abundant nonsportfish species accounting for 72.6% of non-sport composition and 48.% (n = 2,964) of total fish captured. Other non-sport species included, LKCH (n = 446), WHSC (n = 27), LNSC (n = 17), FTMN (n = 87), SPSC (n = 1), TRPR (n = 1) and MNSC (n = 33) (Table ) Length Distribution Of the 2,3 game fish collected at WCD in 27, 3.% or 73 individuals had fork lengths 2 mm. Percentages of sportfish species with fork lengths 2 mm are as follows, 8.4% (n = 17) of RNTR and 2.8% (n = 1) of MNWH (Table 6). The rest of the sportfish found at WCD including BLTR (n = 3), BURB (n = 1) and the CRTR (n = 1) (suspected) hybrid fork lengths all measured 2 mm. A few large non-sportfish (those possessing fork lengths 2 mm) were collected at WCD..9%. (n = 19) of LNSC, 22.2% (n = 63) of WHSC and 3.% of MNSC possessed fork lengths 2 mm. The three BLTR captured possessed fork lengths ranging between 296 mm and 4 mm. The small RNTR collected ranged between 44 mm and 194 mm. RNTR with FL >2 mm ranged between 2 mm and 374 mm. Fork length distributions of MNWH captured ranged between 7 mm and 32 mm (Appendix C). 3.3 Western Headworks Canal Species Composition Eleven species were caught in WHC. RNTR (n = ), BNTR (n = 16) and MNWH (n = 4) comprised the sportfish captured, accounting for only.4% (n = 2) of total fish catch (Table 7). Fish collected from WHC in 27 consisted of a majority of non-game species. BRST (n = 2,), LNDC (n = 2,42) and LKCH (n = 1,14), combined, accounted for 94.% of the Trout Unlimited Canada 22