KOOTENAY LAKE ANGLER CREEL SURVEY

2011

KOOTENAY LAKE ANGLER CREEL SURVEY

2011

Prepared for:

Fish and Wildlife Compensation Program – Columbia Basin 103-333 Victoria St. Nelson, BC

Prepared by:

H. Andrusak, RPBio & Greg Andrusak, RPBio

September 2012

Redfish Consulting Ltd. 5244 Highway 3A Nelson, BC V1L 6N6

Cover Photo: ‘‘Release of a 800 mm (7.6 kg) male Gerrard rainbow trout on Kootenay Lake by Kerry Reed.’ Photograph taken on the 15th of June 2011 by Greg Andrusak.

The Fish and Wildlife Compensation Program is a joint initiative between BC Hydro, the BC Ministry of Ministry of Forests, Lands and Natural Resource Operations (MFLNRO) and Fisheries & Oceans Canada (DFO) to conserve and enhance fish and wildlife populations affected by the construction of BC Hydro dams in Canada's portion of the Columbia Basin.

Suggested Citation: H. Andrusak and G. F. Andrusak. 2012. Kootenay Lake Angler Creel Survey 2011. Report prepared for Fish and Wildlife Compensation Program – Columbia Basin(Nelson, BC) by Redfish Consulting Ltd. (Nelson, BC). FWCP Report 59 pp. + app.

Kootenay Lake Angler Creel Survey-2011

EXECUTIVE SUMMARY

The primary objective of the access point angler survey conducted on Kootenay Lake in 2011 was to provide updated estimates of angler effort, catch and harvest. Prior to the 2011 survey, analysis by Simon Fraser University expertise of large lake creel census methods led to the conclusion that stationary access point interviews for angler catch and effort combined with aerial boat counts were the best approach for such a large lake. Interviews at sampled access points provided only partial information on catch and effort. Non-randomized flights over the length of the lake during peak daily angling activity provided information on the fraction of total effort interviewed by comparing the total number of active fishing boats to the number of interviewed boats active during the flight times. This fraction was applied to the access point data to estimate total daily effort and catch. Survey dates and data collected were stratified by month and daytype (weekend/weekday). The monthly estimates of length of day fishing, species catch and harvest were then expanded using correction factors based on the ratio of access boats sampled to total boats counted by air from a total of 42 flights conducted throughout the year. The aerial based boat counts provided an effective method for estimating total effort.

A total estimate of 201,434 (SE ±12,981) rod hours were spent in 2011 to catch an estimated 15,995 (SE± 1,408) rainbow trout, 6,133 (455) bull trout and 5,377 (SE ±814) kokanee. This equates into a total of 40,416 (SE ± 2,443) angler days fished on the lake during 2011. Release rate for rainbow trout was a very high at 61.5% whereas it was only 40% for bull trout and only 21.7% for kokanee thus estimated annual harvest was 6149 (SE± 584) rainbows, 3,655 (SE ±258) bull trout and 4209 (SE± 574) kokanee. Based on angler responses who fished only for one species most of the effort was directed primarily at the Gerrard rainbow trout population with 38,440(SE 6291±) rod hours (79%) compared to 7,482 (SE 3687±) rod hours (15%) for bull trout and only 2,756 (SE 611±) rod hours (6%) for kokanee. This data matches closely with the KLRT mail-out survey (that does not include kokanee effort) that indicates most anglers (average 85%, 1990-2010) fish for rainbow trout.

The harvested large size rainbow trout and bull trout were in excellent condition (rainbow K = >1.27) and bull trout (K=1.08) but condition (K) was not considered a good indicator of success of lake fertilization owing to uneven seasonal sampling and lack of comparable pre-fertilization data. The Gerrard rainbow trout spawner counts, kokanee spawner counts, in-lake kokanee biomass estimates, rainbow trout growth, and trophic level production measurements all combined are considered to be far better indicators of success of lake fertilization.

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Comparisons are made between the 2011 Kootenay Lake sport fishery statistics and those available from the 1970s and 1980s. Although the survey methods differ with the older data derived from a roving survey design there is reason to believe that estimates of effort, catch and harvest of rainbow trout and bull trout are much higher today than in the 1970s or 1980s. The mean rainbow effort, catch and CPUE (excluding kokanee effort) for 1973-1986 was 114,170 rod hours, catch of 3,575 and CPUE of 0.03, much lower than the 2011 estimates of 198,678 rod hours, 15,995 catch and 0.08 CPUE. The mean bull trout effort, catch and CPUE (excluding kokanee effort) for 1973-1986 was 114,170 rod hours, catch of 1,100 and CPUE of 0.01, much lower than the 2011 estimates of 198,678 rod hours, 6,133 catch and 0.03 CPUE. Despite the differences in survey methods the most comparable data is CPUE and it is quite convincing that the calculated 2011 CPUE rates for rainbow trout and bull trout (0.08 and 0.03 per rod hours respectively) are both substantially higher than any previous year on record. This increase, at least for the Gerrard rainbow trout population, is supported by the impressive increase in Gerrard spawner numbers during the late 2000s with peak counts nearly 1000 compared to only 200-300 in the 1970s and 1980s. The 2011 data also indicates that the larger, older rainbow trout are the fish of greatest interest to most anglers with more than half (54%) of the estimated harvest >50 cm. Mean weight of these larger trout in 2011 was considerably lower than earlier years data but dissimilar sampling procedures may account for the difference. Going forward, a closer examination of mean weights is warranted.

Kootenay Lake fisheries are pre-eminent amongst similar BC large lake fisheries. Although few contemporary surveys exist to make direct comparisons data from Shuswap Lake and Arrow Lakes Reservoir (ALR) are somewhat comparable. In both cases the rainbow trout fisheries target much smaller size trout and angler effort is lower. The ALR rainbow trout fishery has declined in recent years - at least for the largest size trout whereas all indications are the Kootenay Lake rainbow trout spawner numbers and catch are tracking positively. A distinct feature of the Kootenay lake fishery is that effort is year round with success rates and the largest size trout caught during the non-summer months. The ALR fishery tends to be more of a summer time fishery with less effort during the winter months. The 2011 Kootenay Lake kokanee fishery did not generate much attention with effort at or near the lowest on record regardless of method of allocating the 2011 effort. The mean directed effort for kokanee, catch and CPUE for 1973-1986 was 25,379 rod hours, catch of 32,767 and CPUE of 1.29. These estimates are at or higher than the range of 2011 estimates of 2,755 rod-hours for anglers seeking kokanee only (26,068 rod hours for anglers including kokanee as a species sought), 5,377 catch (harvest 4,209) and 0.42-1.26 CPUE dependent upon whether the effort was directed at kokanee only or at kokanee and other species. Total catch has greatly declined from the high levels of ~100,000 in the

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1980s despite high in-lake abundance and no appreciable change in size over time. The ALR kokanee fishery has historically been lower than Kootenay Lake in terms of effort and catch but the CPUEs have been quite similar exceeding 1 fish per rod hour. However the most recent data for the ALR indicates kokanee CPUE has declined to < 0.8/rod hours.

Comparison of the 2011 survey results with previous KLRT survey results was difficult given the availability of only one year’s access point data. It is believed the KLRT effort estimates are positively biased but still close to the 2011 estimate. Data analysis suggests the most comparable statistics between the two surveys are the catch and harvest of rainbow trout > 50 cm.

Increased catch rate and harvest of large size rainbow trout and bull trout assumed to be piscivores bodes well for Kootenay Lake anglers. These metrics as well as others reported in numerous reports such as increased kokanee abundance and Gerrard rainbow trout spawner numbers indicate a positive response of the upper trophic levels to lake fertilization. Moving forward, the Kootenay Lake fisheries warrant close monitoring owing to its economic importance as well as an effective means of monitoring the status of the individual sport fish species. Angler surveys that includes biological data combined with long term monitoring of trophic level responses to lake fertilization provide a powerful measure of success (or failure) of nutrient additions.

A series of recommendations for future angler surveys are made including a repeat in 2013 of the level of effort expended for the 2011 survey. However, it is recognized that the level of future funding may not be available therefore survey scenarios are suggested that include reduced interview effort, reduced lake area covered and variation of aerial boat count surveys. A more comprehensive analysis of options to reduce cost became available during time of writing this report.

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ACKNOWLEDGEMENTS

This report could not have been written without the outstanding statistical analysis conducted by Dr. Carl Schwarz at Simon Fraser University. His work provides scientifically defensible analysis of the multitude of statistics that have been generated from the 2011 survey data. Dr. Schwarz also provided the written description of analytical methods.

Many thanks to the following interviewers who spent a great deal of time at the access points documenting the results of anglers who fished Kootenay Lake in 2011: these include: Bill and Brenda Miller, Clint Tarala, Gary Munro, Sherri Soukoroff, Justin Post, Gillian Sanders, Derek Deiner, Kerry Reed and Les Fleck.

Stefan Himmer conducted virtually all the aerial boat counts with pilots Jennifer and Aaron Cyman of Bear Air located in Creston BC.

Les Fleck is also thanked for his collection of biological samples and logistical support for the interviewers.

Gary Pavan is acknowledged for his fine work in GPS mapping.

Thanks to Gill and Gift Balfour sport shop Balfour BC who freely advertised every census check day over the VHF radio used by most anglers.

Steve Arndt of the Ministry of Forests, Lands and Natural Resource Operations is thanked for his helpful edits and suggestions as well as his attendance at numerous meetings and communications with Redfish Consulting Ltd.

Jeff Burrows of the Ministry of Forests, Lands and Natural Resource Operations is also thanked for his edits to this report. Eva Schindler of the same Ministry provided helpful advice on Kootenay lake trophic level responses to fertilization.

Other Fisheries Technical Committee members of the Fish and Wildlife Compensation Program Trevor Oussoren, Alf Leake and Tom Johnston are thanked for their editorial comments.

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TABLE OF CONTENTS

EXECUTIVE SUMMARY ...... i ACKNOWLEDGEMENTS ...... iv TABLE OF CONTENTS...... v LIST OF FIGURES ...... vii LIST OF TABLES ...... viii 1.0 INTRODUCTION ...... 1 2.0 BACKGROUND ...... 2 2.1 Project Objectives ...... 4 3.0 STUDY AREA ...... 5 4.0 METHODS ...... 5 4.1. Access Point Sampling ...... 5 4.1.1 Stratification of Survey Effort ...... 6 4.1.2 Angler Profiles ...... 7 4.1.3 Survey Data ...... 7 4.1.4 Biological Samples...... 8 4.1.5 Shore Based Fishing ...... 8 4.2 Aerial Surveys ...... 8 4.3 Fishing Derbies ...... 9 4.4 Analysis of Data ...... 9 4.4.1 Fish Condition Factor ...... 10 4.5 KLRT Mail Out Survey ...... 10 5.0 RESULTS and DISCUSSION ...... 11 5.1 Overview of the Fishery ...... 11 5.2 Aerial Boat Counts and Spatial Distribution ...... 11 5.3 Angling Effort ...... 13 5.4 Catch and Harvest ...... 14 5.4.1 Rainbow trout ...... 14 5.4.2 Bull trout ...... 15 5.4.3 Kokanee...... 16 5.4.4 Seasonal CPUE ...... 16 5.5 2011 Survey Results compared Historic Surveys ...... 17 5.5.1 Rainbow trout ...... 17 5.5.2 Bull trout ...... 21 5.5.3 Kokanee...... 22 5.6 Kootenay Lake Fishery Comparison...... 25 5.6.1 Rainbow Trout: Kootenay Lake compared to ALR ...... 26 5.6.2 Bull Trout: Kootenay Lake compared to ALR ...... 27 5.6.3 Kokanee: Main Kootenay Lake compared to ALR ...... 28 5.7 KLRT Mail Out Survey ...... 28

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5.7.1 Estimated Effort ...... 29 5.7.2 Estimated Catch ...... 30 5.8 Survey Logistics and Limitations ...... 31 6.0 RECOMMENDATIONS ...... 32 6.1 Future surveys ...... 32 7.0 CONCLUSIONS ...... 35 8.0 REFERENCES ...... 36 APPENDIX 1–Access Creel Angler Data Sheet ...... 59 APPENDIX 2–Access Creel Biological Data Sheet ...... 60 APPENDIX 3. Creel Census Data Analysis ...... 62 1. Estimates of catch and related variables ...... 63 2. CPUE ...... 67 3. Angler profile ...... 68 APPENDIX 4- Creel Census on Other Southern BC Large Lakes ...... 69

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LIST OF FIGURES

Figure 1. Kootenay Lake and creel survey access points. Riondel/Crawford Bay and Boswell/Kuskanook ramps were combined for field monitoring and data analysis...... 43 Figure 2. Winter-time (January-March) aerial boat counts at each stratum of Kootenay Lake. Note concentration of boats in the central area...... 44 Figure 3. Spring-time (April-June) aerial boat counts at each stratum of Kootenay Lake. Note heavy concentration of boats in the central area and more widespread distribution ..... 45 Figure 4. Summer-time (July-September) aerial boat counts at each stratum of Kootenay Lake. Note heavy concentration of boats in the central area as well as more boats throughout the lake, especially the extreme ends of the lake...... 46 Figure 5. Fall months (October-December) aerial boat counts at each stratum of Kootenay Lake. Note concentration of boats in the central area with fewer boats at extreme ends of the lake...... 47 Figure 6. Estimated angler effort (rod hrs) December 2010, January-November 2011. Vertical bars indicate standard error...... 48 Figure 7. Seasonal angler effort pattern expressed as percent of total rod hours per month 1983-1986, 2011...... 48 Figure 8. Estimated angler effort (rod h) and standard error bars for each month at each of the five access points...... 49 Figure 9. Total estimated catch of rainbow trout December 2010, Jan.-Nov. 2011. CPUE displayed on the secondary Y-axis illustrates the highest rates (and catch) were in the fall-winter months (Oct.-Dec.) ...... 50 Figure 10. Length frequency distribution of angler caught rainbow trout in Kootenay Lake 2011 (n=326). Upper panel all rainbow trout captured in 2011, middle panel represents non- summer months (Oct-May n=197) and lower panel represents summer months (Jun-Sept n=129)...... 50 Figure 11. Total estimated catch of bull trout Dec. 2010 - Nov. 2011. The CPUE displayed on the secondary Y-axis illustrates the highest rates were in the late winter months (Jan.- April)...... 51 Figure 12. Length frequency distribution of angler caught bull trout in Kootenay Lake 2011 (n=220). Upper panel all bull trout captured in 2011, middle panel represents non- summer months (Oct-May) and lower panel represents summer months (Jun-Sept). ... 51 Figure 13. Total estimated catch of kokanee June-August 2011.. The CPUE displayed on the secondary Y-axis illustrates the highest rates were in July and August and is for anglers specifically targeting kokanee only...... 52

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Figure 14. Length frequency distribution of angler caught kokanee in Kootenay Lake 2011 (n=7)...... 52 Figure 15. Catch per unit effort (CPUE) for kokanee (KO), bull trout (BT) and rainbow trout (RB) from Kootenay Lake in 2011. Note scale change by panel...... 53 Figure 16. Gerrard rainbow trout spawner peak count from 1957-2011. Vertical lines represents commencement of North Arm (1992) and South Arm (2004) nutrient addition(data from MNFLRO file data)...... 54 Figure 17. Length frequency distribution of rainbow trout > 50 cm collected in 1966, 2004 and 2011 on Kootenay Lake. (1966 & 2004 data from Andrusak and Andrusak 2006)...... 54 Figure 18. Length-weight relationship for rainbow trout (> 50 cm) on Kootenay Lake, pre dam (1966), pre-nutrient (1981-1992) and post-nutrient (1994-2011) eras. (data from Andrusak and Andrusak 2006)...... 55 Figure 19. Condition factor for rainbow trout (> 50 cm) on Kootenay Lake, pre-nutrient (1981- 1992) and post-nutrient (1994-2011) eras...... 55 Figure 20. Scatter plot depicting relationship between angler rod hours and mean length of Meadow Creek male kokanee 1969-1986, 2011 ...... 56 Figure 21. Size at age of kokanee on Kootenay Lake from 1985-2010. (Data from Sebastian et al. in Schindler et al. 2012 draft)...... 57 Figure 22. Trends in kokanee biomass density (kg/ha) for Kootenay Lake based on acoustic and trawl surveys 1985-2010. Dotted vertical lines indicate commencement of North and South Arm fertilization (Data from Sebastian et al. in Schindler et al. 2012 draft)...... 57 Figure 23. Estimated KLRT angler rod hours, angler days and average hours per angler day (1987-2007; triangles) compared to the 2011 survey (redd circle)...... 58

LIST OF TABLES

Table 1. Location (UTM) of access points for Kootenay Lake creel surveys in 2010-2011...... 6 Table 2. Spatial stratification of zones on Kootenay Lake...... 7 Table 3. Kootenay Lake derbies covered in creel census in 2011...... 9 Table 4. Sampling effort for 2010-11 creel census survey on Kootenay Lake that included: 1) stratified random access survey and 2) non-random aerial survey for weekends (WE) and weekdays (WD) including second flight same day. All derby flights were on weekends. .... 12 Table 5. Kootenay Lake stratums, their location and boundary descriptions with 2011 percentage of boats in each stratum based on aerial counts...... 13 Table 6. Estimated effort from the access & aerial surveys on Kootenay Lake in 2011...... 13

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Table 7. Percent of total estimated rod hours recorded at the five access points on Kootenay Lake in 2011...... 14 Table 8. Catch statistics of the 2011 Kootenay Lake sport fishery based on the access & aerial surveys...... 14 Table 9. Biological information collected on fish sampled at access points on Kootenay Lake in 2011. Lengths and weights are the mean values...... 15 Table 10. Estimated rod hours, rainbow trout (RB) catch and CPUE on Kootenay Lake based on a roving creel census (1973-1986) and access point survey 2011. Data for 1973 to 1986 (Andrusak 1987)...... 18 Table 11. Creel census data (length, weight, age, condition factor, all sizes) for Gerrard rainbow trout from 1966, 1988-1991 and 2003-2004 on Kootenay Lake. Data includes 95% CI for each variable. Data from Andrusak and Andrusak (2006)...... 20 Table 12. Mean length, weight, and calculated K (± confidence limits) factors for Kootenay Lake rainbow trout harvested during pre-fertilization era, early fertilization era and most recent years of lake fertilization...... 21 Table 13. Estimated directed rod hours and bull trout catch on the main portion of Kootenay Lake based on a roving creel census (1973-1986) and access point survey 2011. Data for 1973 to 1986 (Andrusak 1987)...... 22 Table 14. Mean length, weight and condition factor for harvested bull trout sampled during 2011...... 22 Table 15. Estimated rod hours, main lake kokanee catch, CPUE and mean size of Meadow Creek kokanee males. Data based on a roving creel census (1973-1986), Meadow Creek spawning channel and 2011 survey...... 24 Table 16. Rainbow trout estimated catch and CPUE for Kootenay Lake and ALR for those years with comparable data...... 27 Table 17. Bull trout catch and CPUE for Kootenay Lake and ALR for those years with comparable data...... 27 Table 18. Mean kokanee catch and CPUE for Kootenay Lake and ALR for those years of comparable data...... 28 Table 19. Estimated catch and CPUE for Kootenay Lake rainbow trout and bull trout based on the KLRT survey (1987-2007) and the 2011 access point survey...... 30 Table 20. Estimates of catch, released and harvested rainbow trout (RB) and bull trout (BT) > 50 cm (2 kg) based on the ten year average of KLRT data and that generated by the 2011 survey...... 31

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1.0 INTRODUCTION

The recreational sport fishery on Kootenay Lake, British Columbia, has long been one of North America's pre-eminent large lake fisheries. The lake and its supporting fisheries provide a significant benefit to the local eco/tourism economy and have been an integral part of the Kootenay Region recreational fisheries for residents of British Columbia, other residents of Canada and the United States for many decades. By the 1960s this fishery was so large that the provincial government made its first attempt to place a value on a recreational sport fishery (Pearse and Laub 1965). Predominantly, fishing effort is directed at two forms of rainbow trout (Oncorhynchus mykiss): an insectivorous trout that feeds almost exclusively on terrestrial and aquatic invertebrates and is typically < 50cm while the most popular fishery targets a population of pelagic piscivorous Gerrard rainbow trout that are considered the world’s largest, frequently obtaining sizes of 10-13 kg (Cartwright 1961; Ashley et al. 1999; Andrusak 2005). In addition to fishing for rainbow trout anglers also actively fish for bull trout (Salvelinus confluentus) and kokanee (Oncorhynchus nerka). With the unique size of the trout and the popularity of the fishery it is not surprising that the lake has been the focus of numerous scientific studies related to the various fisheries and especially work directed at the Gerrard rainbow trout and kokanee populations (Northcote 1973; Daley et al. 1981; Andrusak and Thorley 2011; Kurota et al. 2011).

Over the last half century substantial ecological alterations have taken place in Kootenay Lake and many of its important tributaries that support spawning and rearing for the primary sport fish species. In particular, nutrient retention in upstream reservoirs formed by hydro-electric dams on the major Kootenay Lake tributaries resulted in a decline in lake productivity to an oligotrophic condition (Daley et al. 1981; Ashley et al. 1997; Moody et al. 2007). The productivity decline and state of trophic depression (Ney 1996) in turn caused a near collapse of the kokanee population. The significant decline in kokanee abundance in the late 1980s (Ashley et al. 1997) prompted alarm amongst fisheries managers and the public especially as it may impact the Gerrard rainbow trout and bull trout populations. Initiation of the Kootenay Lake fertilization project in 1992 (Ashley et al. 1997) was an attempt to restore the primary nutrient balance within the lake that had been changed as a result of closure of a fertilizer plant on a Kootenay River tributary and nutrient retention in the two upstream reservoirs (Larkin 1998; Ashley et al. 1999). The decline in lake productivity and possibly increased competition for food between mysids and kokanee led to a reduction in main lake kokanee size and numbers in the early 1990s (Ashley et al. 1997). After 20 years of intense monitoring it is quite apparent from trends of trout abundance that fertilization is providing benefits to the higher trophic levels within Kootenay Lake. Most important, kokanee spawner numbers have rebounded to near peak levels (Schindler et al. 2010a).

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Collection and analysis of biological data from the Gerrard rainbow trout fishery and kokanee data from Meadow Creek spawning channel have been the primary data sources for fisheries managers in assessment of their populations. Historically, collection of biological data by means of an annual creel census had been an integral part of monitoring these populations (Andrusak 1987). Creel census surveys were conducted annually from the early 1960s to 1986 while a less intensive one continued through to 1989 when it was cancelled altogether. A more cost effective but less accurate mail survey questionnaire was established in 1987.

From December 2010 through to November 2011 the Fish and Wildlife Compensation Program-Columbia Basin (FWCP) initiated an access based creel survey1 supported by aerial boat counts from a fix winged plane on the main lake portion of Kootenay Lake in an effort to update annual effort and catch statistics. This report summarizes the results of this survey and provides analysis and summarizations of long term trends based on previous surveys. 2.0 BACKGROUND

Kootenay Lake is renowned for its exceptional fishing, particularly for Gerrard rainbow trout and bull trout. It is the remarkable average size of both the Gerrard rainbow trout and bull trout that attracts anglers from throughout the Pacific Northwest. The trophy size of the Gerrard rainbow trout is directly attributed to their highly piscivorous behaviour and reliance on kokanee as their primary food source (Andrusak and Parkinson 1984). The fishery for Gerrard rainbow trout occurs throughout the year but the most productive and heavily fished months are November and May when these trout are especially vulnerable on the surface of the lake (Andrusak 1987). Comparatively, there is very little effort directed towards these trout during the summer months when they move to the deep, cooler water.

A considerable amount of research has been dedicated to understanding the biology of the Gerrard rainbow trout, including a description of their general life history by Cartwright (1961), spawning behaviour by Hartman (1969) and juvenile rearing requirements in the Lardeau River by Irvine (1978), Slaney and Andrusak (2003) and currently by Andrusak and Thorley (2011). This unique trout population is almost entirely dependent upon the Lardeau River, the only remaining system within the basin where they are known to successfully spawn and rear. Total numbers of spawners have been estimated at 800-1,200 annually (Irvine 1978; Hagen and Baxter 2002, draft report) however in the last five years escapement numbers have more than doubled the long term 50 year average.

1 For the purposes of this report the creel census that took place from December 2010 to November 2011 is simply referred to as the 2011 survey.

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Kootenay Lake has also been the focus of intensive limnological studies for well over five decades. Early work by Larkin (1951) considered some of the basic limnological features; Northcote (1973) detailed the impacts on fish of early placer mining, intense logging practices, agricultural diking and irrigation. Daley et al. (1981) summarized the decline in lake productivity due to upstream dams located on the major tributaries to Kootenay Lake. More recently, the limnology of Kootenay Lake and particularly the status of North Arm kokanee have been well documented as a result of a series of applied research initiatives designed to increase kokanee numbers (see Ashley et al. 1997; Ashley et al. 1999; Thompson 1999; Sebastian et al. 2010a).

As noted earlier the response by fisheries managers to the dramatic decline in kokanee numbers in the 1980s was to initiate an ambitious experiment to fertilize a small portion of the North Arm of Kootenay Lake commencing in 1992. The primary objective of the fertilization experiment was to restore depressed nutrient levels in the lake resulting from the impoundment of nutrients in upstream reservoirs formed by the Duncan (1967) and Libby (1972) Dams (Larkin 1998; Ashley et al. 1999; Moody et al. 2007; Utzig and Schmidt 2011). By 1996, the North Arm kokanee population had recovered to near historical numbers (Ashley et al. 1997) and Meadow Creek escapements (the dominant spawning population in the system) was once again supporting >1 million spawners (Sebastian et al. 2010a). The FWCP funds the annual North Arm fertilization program and the operation and evaluation of the Meadow Creek spawning channel as partial compensation for impacts due to upstream hydro developments. Commencing in 2005 South Arm fertilization began funded by Bonneville Power Authority (BPA) through the Kootenai Tribe of Idaho (KTOI). Monitoring angler effort and catch is an additional method of evaluating the biological success of the fertilization program (s).

Historically the Gerrard rainbow trout fishery from the mid-1960s until the late 1980s was monitored by means of a whole lake roving style creel census and annual daily counts of spawner numbers at Gerrard BC. Budget reductions in the late 1980s forced fisheries managers to eliminate the census program. Today the Gerrard rainbow trout fishery is monitored only through the annual escapement counts and the angler KLRT questionnaire survey introduced in 1987. This survey was created to partially replace the annual creel census after Andrusak and Brown (1987) identified that the exploitation rate for these large trout could be as high as 80%. This mail-out survey provides trend data on the fishery with the most recent summary report completed by Redfish Consulting Ltd. (2007). Since the inception of the KLRT stamp Kootenay Lake anglers have developed a strong conservation ethic and today there is a high level of catch and release especially for the Gerrard rainbow trout and to a lesser extent bull trout. Unfortunately there has been little biological data collected from the fishery after the creel census was terminated. Most recently the lack of monitoring capability and lack of updated data of this provincially important rainbow trout stock in Kootenay Lake has

3 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 been troubling given the value and importance of this unique race of trout. The intensity of the fishery is a concern since it is believed the Gerrard stock or at least the oldest age groups have been over-fished in the past (Redfish Consulting Ltd. 2002). Collection of biological data (age, size-at-age and fecundity) from the sport fishery is considered critical for assessing the state of this stock and managing it sustainably. Furthermore, the data could be invaluable in evaluating the success of the lake fertilization program.

Bull trout fishing on Kootenay Lake is also very popular and they are often caught while anglers fish for Gerrard rainbow trout. They also provide good fishing during the winter and spring months when many of the mature rainbow trout move to the north end of the lake as part of their spawning migration to Gerrard. Until very recently main lake bull trout information was limited to data obtained from earlier creel surveys and some very interesting work on bull trout passage through the Duncan Dam (O’Brien 1999; Hagen and Decker 2009). Concern by fisheries managers as to the status of this blue listed species led to commencement of spawner surveys (redd counts) on two tributaries initially on the Kaslo River in 2006 and in 2008 on Crawford Creek (Andrusak 2010). This initial work led to development of a plan for monitoring of all bull trout spawners (Hagen and Decker 2009). Concomitantly acoustic tagging and tracking of angler captured Gerrard rainbow trout and bull trout was underway (Thorley and Andrusak 2010). Most recently an assessment of adfluvial bull trout spawning in the majority of the tributaries was completed in October 2011 (Andrusak and Andrusak 2012).

Main lake kokanee fishing is generally restricted to June-August when mature size fish are vulnerable to fishing. The vast majority of kokanee spawn at the Meadow Creek spawning channel and their numbers, size and age are monitored annually (Schindler et al. 2010a).

2.1 Project Objectives

 To provide reliable estimates of angler effort, catch and harvest (with precision estimates incorporating uncertainty from access point data and over-flight boat counts) for a one year period on the main lake portion of Kootenay Lake.

 To measure access point catch per unit of effort (CPUE) for comparison to the Arrow Lakes Reservoir access creel survey, Kootenay Lake Rainbow Trout (KLRT) mailed creel survey), and other relevant studies.

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 To collect biological data on harvested fish including structures for aging that can be used to assess the size/age structure of the harvest and the feeding conditions in the lake. 3.0 STUDY AREA

Kootenay Lake, located in the upper Columbia River drainage of Southeast British Columbia, lies between the Selkirk and Purcell Mountain ranges (Figure 1). The main lake is 107 km long, approximately 4 km wide with a mean depth of 94 m and a maximum of 154 m (Daley et al 1981). The lake is fed by two major river systems: the Lardeau/Duncan system at the north end and the Kootenay River that flows into the south end. Kaslo is the only town of any size located on the main lake, located about midpoint on the north arm. The shoreline of the north arm is sparsely populated whereas the east side of the south arm is virtually all privately owned with permanent and or summer homes. The west side of the south arm is totally uninhabited except for the CPR railway that follows the shoreline for its entire length. The outlet of the main lake, at Balfour, British Columbia, forms the upper end of the West Arm. At this outlet, a sill lies at a depth of approximately 8 m producing a distinct boundary between the main lake and the West Arm. The West Arm is about 40 km long with a mean depth of only 13 m. The entire north side of the arm is habituated with permanent homes whereas most of the south side is only sparsely developed. The upper part of the west arm at Balfour is where most anglers dock their boats year round. The west arm is physically and limnologically different from the main lake, comprised of a series of shallow basins interconnected by narrow riverine sections. It flows in a westerly direction becoming the lower Kootenay River, which flows into the Columbia River at Castlegar, BC.

The area covered by the 2011 creel survey excluded the West Arm fisheries. i.e. only anglers fishing in the main lake (north and south arms) were surveyed. 4.0 METHODS

4.1. Access Point Sampling

Access point surveys concentrated on five sites on Kootenay Lake including: Balfour, Woodbury, Kaslo, Riondel/Crawford Bay and Kuskanook/Boswell (Figure 1, Table 1). In some cases, these stations included more than one access site (sub-sites) that were utilized to varying degrees by anglers and the census technicians sampled these on an opportunistic basis especially the sub-sites of Lost Ledge north of Kaslo and Boswell north of Kuskanook. The rationale for selecting the five access points was based on the analysis within the feasibility study (Anon 2010) which indicated no detectable

5 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 difference in catch per unit effort (CPUE) between sites during the fall-winter months (Schwarz 2010), i.e., the five access points selected represent the highest use areas on the lake and the results indicated that there was little variation in CPUE amongst the sites. While the sample sizes were small in the Anon (2010) feasibility study, it was believed that these sites represent the highest use sites and representative of all anglers on the lake. It should be noted that most of the field technicians knew the local anglers or quickly identified who fished from their homes located on or near the lake, especially those living at Balfour, Riondel and Kuskanook. Although most anglers were interviewed on site many of the known anglers were contacted by the technician either by direct contact, VHF radio or by cell phone to obtain full day fishing data. The sport shop at Balfour also announced over VHF radio every survey day that a census was being conducted.

Shore anglers were excluded from the analyses due to inadequate sampling on the ground and difficulties in getting reliable air counts of shore based anglers.

Table 1. Location (UTM) of access points for Kootenay Lake creel surveys in 2010- 2011. Access Point Access Ramp UTM Zone UTM Northing UTM Easting 1 Kaslo 11 506844 5528215 1 Lost Ledge 11 504350 5549751 2 Woodbury 11 506287 5513175 3 Balfour 11 502894 5497256 4 Riondel 11 510259 5512317 4 Crawford Bay 11 512550 5500206 5 Kuskanook 11 517197 5479295 5 Boswell 11 516929 5478778

4.1.1 Stratification of Survey Effort

The access point survey implemented a stratified randomized sampling design (Pollock et al. 1994) recommended by Schwarz (2010). Stratification of effort followed previous Kootenay Lake surveys by sampling weekdays (WD) separately from weekends (WE) during December 2010 to November 2011 (Andrusak 1987; Anon. 2010). Based on the review by Schwarz (2010), it was also critical to have a minimum of two replicates of each survey unit within a stratum to obtain estimates of precision. Thus, approximately equal numbers of days were sampled on weekends and weekdays with slightly more effort on weekdays during high effort months (Schwarz 2010; Anon. 2010). Therefore due to lower effort during the winter the design included only one weekday and two weekend days in January, February and March. Based on previous surveys on Kootenay

6 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Lake the highest number of survey days were assigned during May-July and October- November. This stratification was added to the design to improve the overall precision.

4.1.2 Angler Profiles

Based on Schwarz (2010), it was not recommended that sub sampling within days be undertaken due to the difficulties of extrapolating from half days to full days and based on the requirement of coordination with over-flights. Therefore, full day sampling was implemented within the design for the five access points. The survey interviewers were on station at their access point from 2 h after sunrise to dark for April 1 – Oct. 15 ( warmer seasons) and from 10:00 AM to dark for Oct. 16 - Mar 31 (shorter days and colder). During the months of May-July with much longer periods of daylight the work day was split into two with one clerk starting in the early morning and the second person relieving the first at mid-day. The assumption in the creel design was that no anglers (or a negligible number) would return prior to the starting times so that the full daily period of fishing was covered by the interviewer.

Anticipating future surveys on Kootenay Lake the lake was stratified into spatial zones (Table 2) that were recorded by the ground survey technicians for each boat (anglers) interviewed. The location of each boat counted from the air was also assigned to a stratum. This information could be used to determine future allocation of sampling effort if budget limitations are imposed.

Table 2. Spatial stratification of zones on Kootenay Lake.

Zone Location Description 1 North Arm from Kaslo north end of lake 2 North Arm from Kaslo to Riondel/Ainsworth 3 Central from Riondel to 20 min Pt. 4 South Arm from 20 Min Pt. to Boswell 5 South Arm from Boswell to south end of lake

4.1.3 Survey Data

At each of the five access points anglers were intercepted as they came ashore usually by boat at the end of their fishing day. Anglers were interviewed by the survey technicians to obtain basic data on catch and effort. Questions included: lake stratum fished, fishing start time, fishing stop time, # anglers, # rods, species sought, # species caught, # released, guided or not guided, possession of a KLRT stamp, residence, city, province or state. The actual survey form is displayed in APPENDIX 1.

7 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

4.1.4 Biological Samples

During the year the survey technicians on an opportunistic basis obtained biological data from harvested fish detailed in APPENDIX 2–Access Creel Biological Data Sheet. The technicians were instructed to sample all fish in an angler’s possession or none in order to avoid bias. Most often anglers had already cleaned their fish thus preventing the opportunity to obtain any meaningful data. When whole fish were sampled their length (cm), weight (kg), sex and state of maturity (if possible) were recorded. Scale samples were taken from rainbow trout while heads were collected from bull trout for their otoliths.

4.1.5 Shore Based Fishing

From the onset of the survey fishing from the shore was not considered to be a significant factor on Kootenay Lake due to access limitations imposed either by private land or steep-sided rocky slopes. There are very few places the public can fish from shore via foot access the most significant ones being Davis Creek, Lost Ledge Creek, Queens Bay Point and Blue Point (Boswell). The remaining shore based fishing usually off creek mouths occurred primarily by means of boat access. Of the four locations identified above it was felt that Lost Ledge supported the most fishing followed by Davis Creek. These two sites were sampled opportunistically by the Kaslo census technician primarily during the July-September period.

4.2 Aerial Surveys

Aerial over flight information provides information on total effort in the fishery (Pollock et al. 1994). Combined with access survey information, aerial over flights are critically important in covering large spatial areas similar to Kootenay Lake (394 km2). This element of survey was not conducted in the earlier surveys described by Andrusak (1987).

The 2011 aerial over flight sampling implemented a stratified non-randomized design which relied on point access survey information for estimating total fishery statistics. The flights were all conducted from the Creston BC airport outbound to the north end of the lake and return back to Creston. The flights were generally conducted between 12:00-14:30 h during the known peak of daily angling activity (Schwarz 2010). The outbound and return trip instantaneous aerial counts were conducted during this time period to maximize the number of boats observed and to reduce the variability in the expansion factor. Generally the flights were conducted along the center axis of the lake and boat positions were recorded using a GPS. This permitted the boats to be assigned to the appropriate stratum outlined in Table 2. Aerial surveys were conducted on 36 days with a total number of 42 flights on the account of the double flights (6) conducted

8 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 on the mid-day/evening summer time days. The first flight generally occurred around 12:30h with the second flight recording boats towards the evening, i.e., 16:00-18:00h. The rationale for the double flights was that increasing the sampling during these peak times would provide more accuracy to the estimates (Pollock et al. 1994; Schwarz 2010). The summer months were more difficult to conduct the boat counts due to the presence of non-fishing recreational boating. The aerial flights discerned between fishing and non- fishing boats by lower flight elevations to confirm fishing rods and lines. Both types of boat activity were recorded.

4.3 Fishing Derbies

Fishing derby days were treated as a separate stratum for the field sampling (Schwarz 2010). The design included all five access sampling points coordinated with over-flights to assess effort on five weekend days from a total of fifteen derby days (Table 3). Estimated effort on these days can be compared with weekend data for that month to determine how much increased effort occurred due to the derby. Data from the sampled derby days were used to extrapolate catch and effort for all fifteen derby days and were treated as weekend days for analyses. The following summarizes the dates and number of derby days:

Table 3. Kootenay Lake derbies covered in creel census in 2011.

Location Derby name Dates # of days Woodbury Woodbury Dolly Derby 23-Apr-2011 Fri-Sun 3 Balfour Gill and Gift Bill King Memorial Derby 22-May-2011 Fri-Sun 3 Woodbury Woodbury Thanksgiving Derby 08-Oct-2011 Fri-Sun 3 Balfour Nelson City Police Derby 16-Oct-2011 Fri-Sun 3 Kaslo Kaslo Remembrance Derby 12-Nov-2011 Fri-Sun 3

4.4 Analysis of Data

Statistical methods used in the analysis of the 2010-2011 creel survey data have been previously used on Arrow Lakes Reservoir as described by Arndt and Schwarz (2011). An Access database was developed to input the angler interview data. Data were then transferred to SAS (SAS Version 9.3) for estimates of effort, catch and harvest. SAS programming was done at Simon Fraser University. Effort and catch estimates in this report were conducted by Dr. Carl Schwarz, Department of Statistics and Actuarial Science, Simon Fraser University. Monthly site-specific estimates (and standard errors) for angler effort, catch and harvest were computed by expanding the average for each daytype (WD or WE) in each month by the number of days of that daytype (see Schwarz 2012; APPENDIX 3. Creel Census Data Analysis).

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The Kokanee CPUE was computed slightly differently than that described by Schwarz (2012) found in APPENDIX 3. To derive a CPUE more comparable to previous surveys on Kootenay Lake, this report primarily used effort and catch for kokanee “only” anglers recorded during June, July, and August. However, because anglers also reported fishing for kokanee plus other fish species a second CPUE was calculated. The CPUE for these two groupings of kokanee anglers (kokanee only, kokanee plus other species) was computed separately from the raw data (only) as follows: for a ‘kokanee only’ CPUE, all parties that reported seeking only kokanee were queried from the database, and total rod-hours and total catch from these parties were summed and used for the CPUE. For a ‘kokanee and other species’ CPUE, all parties that included kokanee as a species sought were also queried. Their rod-hours were divided by the number of species listed before summing (e.g., for a party fishing 6 h seeking Bull trout, kokanee and rainbow trout, the kokanee rod-hours = 6/3 = 2), and then total kokanee catch from the same parties was divided by the sum of these adjusted rod-hours to compute the CPUE.

4.4.1 Fish Condition Factor

Using biological data on fish collected by access point survey technicians, condition of bull trout and rainbow trout > 50 cm was determined using the well-established Fulton 3 formula: K = (W/L ) described by Ricker (1975). The purpose of generating condition factors is to make reference to feeding conditions in the lake as a result of lake fertilization. A comprehensive discussion on the utility of this metric and its limitations can be found in Pope and Kruse (in Guy and Brown 2007).

4.5 KLRT Mail Out Survey

A requirement under the BC fishing regulations is that an angler fishing on Kootenay Lake must purchase a Kootenay Lake rainbow tag (stamp) if one wishes to harvest a rainbow trout > 50 cm. An annual limit (quota) of only five rainbow trout > 50 cm can be harvested in a licence year. A subsample of those licensees who purchased a KLRT stamp were randomly selected and mailed a questionnaire the following year. The questions were focussed on angler effort, rainbow and bull trout caught and numbers released. The KLRT survey does not include statistics on anglers who did not purchase a KLRT or those fishing for kokanee. In an effort to determine the relationship between the 2011 creel census results in this study and the annual KLRT mail out survey results the access point interviewers recorded whether or not the interviewed angler possessed a KLRT stamp. No KLRT summary data was available after 2007.

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5.0 RESULTS and DISCUSSION

5.1 Overview of the Fishery

The 2011 sport fishery on Kootenay Lake was quite consistent with previous years in terms of directed effort, methods, seasonal variation and species harvest. The focus of angler effort was the large size Gerrard rainbow trout with a secondary interest in bull trout. Kokanee were of only passing interest during the summer months primarily at the outlet area of the lake and at Woodbury Resort. On occasion a few anglers caught mountain whitefish, (Prosopium williamsoni) and northern pikeminnow (Ptychocheilus oregonensis) but neither species were of significance to the total catch or effort. Trolling was by far the method of choice for anglers who targeted the large trout by trolling using either bucktail flies or an assortment of plugs the most popular being Lyman plugs, apex lures, J-plugs and Billy Normans. All lures used were aimed at mimicking sub adult and adult size kokanee. During most of the year many anglers used down riggers to troll plugs at deeper depths and or planer boards to troll bucktail flies on the surface. However, in the warm summer months some anglers switched to smaller trolling lures targeted at kokanee and smaller size rainbow trout.

Large size rainbow trout were caught year round throughout the lake but the fall, winter and spring months were the preferred times of the year for anglers seeking the “big one”. During these months the rainbows tended to be at or near the surface hence bucktail flies on planer boards were the single most popular lure and method used. Smaller rainbow trout, many of which were likely the non-piscivorous stock (s) were sought during July-September. Bull trout were caught throughout the lake with most caught during the non-summer months, often at deeper depths (30-75 m) using down riggers with plugs or large flashers. Kokanee catches were limited to June-November with most caught during July on pink/red colored small lures.

5.2 Aerial Boat Counts and Spatial Distribution

A total of forty two over-flight boat counts were conducted between December 2010 and November 2011 (Table 4). The flights commenced at the south end near Creston BC flying northward to the end of the lake and returning to land at Creston BC. The counts during Dec-May and October, November were conducted during single flights at or near the peak of angler activity that usually ranged from 11:00-14:00 h. Two flights per day occurred in May (n=3), June (n=2) and July (n=1) in anticipation of two peaks of effort within one day. On these days the first flight generally occurred around 12:30h with the second flight recorded boats towards the evening. i.e. 16:00-18:00h. These second flights were intended to provide more accuracy for effort estimation. During the flights

11 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 boat locations were recorded by GPS and assigned to one of the five pre-determined stratums of the lake. Non-fishing boats were recorded separately.

Table 4. Sampling effort for 2010-11 creel census survey on Kootenay Lake that included: 1) stratified random access survey and 2) non-random aerial survey for weekends (WE) and weekdays (WD) including second flight same day. All derby flights were on weekends. Day-type Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals WD Access 1 1 1 2 3 3 3 3 3 3 3 2 28 WE Access 2 2 2 3 5 4 4 3 2 4 3 2 36 # Access Points 5 5 5 5 5 5 5 5 5 5 5 5 60 Derby Days 0 0 0 1 1 0 0 0 0 2 1 0 5 WD Flights 1 0 1 1 2 2 2 2 2 1 1 1 16 WD Flights (2nd) 0 0 0 0 2 1 0 0 0 0 0 0 3 WE Flights 1 0 1 2 2 2 2 2 2 2 2 1 19 WE Flights (2nd) 0 0 0 0 1 1 1 0 0 0 0 0 3 # Derby Flights 0 0 0 1 0 0 0 0 0 2 0 0 3

The over flight boat counts throughout the year revealed that most anglers concentrated their fishing effort in the central part of the lake (Woodbury Resort-20 Minute Point) where the vast majority of fishing occurred (see effort discussion below), especially in the winter (Figure 2 - Figure 5). The majority of anglers fished out of the access points at Balfour, Woodbury Creek resort, Kaslo, Kuskanook and only to a minor extent from Crawford Bay. Fishing effort represented by the combined boat counts (outbound plus inbound counts) for the twelve month period was 3,398 boats. Of this total 20% were counted in each of strata 1 and 5 at the north and south ends of the lake with the majority (60%) of boats were counted in strata 2-4. Within these strata the central area of the lake, especially between Woodbury Resort and Twenty Minute Point, was the most popular area year round with the greatest number of boats accessing the lake from the Balfour and Woodbury area stations (Figure 2 - Figure 5; Table 5). As the weather turned colder during the fall-winter months and boat ramp access became restricted due to snow angler effort concentrated in the central portion of the lake. As spring approached and throughout the summer the boats became more widespread extending to the extreme ends of the lake. Interestingly, most boats were recorded by GPS as fishing close to the shoreline except for the area adjacent to the Woodbury Creek resort.

Angler composition consisted of residents of BC (77%), non-residents of Canada (18%) and non-resident aliens (5%). This is very similar to that determined from the KLRT survey discussed later in this report.

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Table 5. Kootenay Lake stratums, their location and boundary descriptions with 2011 percentage of boats in each stratum based on aerial counts. Stratum Location Description % of total # boats counted1 1 North Arm from Kaslo north end of lake 20% 2 North Arm Kaslo to Riondel/Ainsworth 19% 3 Central from Riondel to 20 min Pt. 28% 4 South Arm from 20 Min Pt. to Boswell 13% 5 South Arm from Boswell to south end of lake 20% 1. Count is the total of outbound and inbound counts= 3398

5.3 Angling Effort

A total of 201,434 rod hours were estimated on Kootenay Lake in 2011 (Figure 6, Table 6). The 2011 seasonal effort pattern was very similar to that recorded in the last three annual surveys in 1983-1986 (Figure 7). The only real difference from previous years was in 2011 summer-like weather was very late (mid-July) resulting in prolonged spring fishing conditions where anglers fished the surface waters for large rainbows. An estimated total of 40,416 angler days fished the lake during 2011 thus the average rod hours fished per day was 4.98. This level of angler effort is compared to effort estimates made in the 1980s later in this report. There was a considerable difference in seasonal distribution of effort and access point data. The lowest fishing effort was during the winter months (Dec-Feb.). As spring approached angler effort increased through May, declined slightly in June and peaked in July (Figure 6). Spring-like conditions extended well into July and then effort declined during the warmer months of August and September but increased to the highest level of the year in October before declining slightly in November. There were some differences in patterns of angler effort amongst the five access points. At Balfour effort was lowest during the winter steadily increasing through to June, declining in August-September and then increasing to the highest level in October-November (Figure 8). Constant but low levels of effort were estimated at Riondel with a similar pattern at Kaslo. Two peaks of angler effort were recorded at the Woodbury Resort: a spring peak and a second peak in the fall. Angler activity recorded at the Kuskanook site was different from the other stations with relatively low effort levels from December-June with peak activity during July-August.

Table 6. Estimated effort from the access & aerial surveys on Kootenay Lake in 2011. Effort Total ± SE Rod hours 201,434 13,521 Angler hours 189,457 12,981 Angler days 40,416 2,443

The percentage of total 2011 angler effort estimated from each access point is also shown in Table 7. The Balfour station interviewed one third of all anglers surveyed while in sharp contrast the Riondel station only accounted for only 7%. The Balfour station

13 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 was the most difficult location for interviewing anglers due to the high number of private docks, many of which were out of reach of the stationary interviewer because they were located on the opposite shore (Proctor) or further downstream also out of reach. On numerous occasions boats would also be missed due to several coming on shore at the same time. Difficulty also was experienced at Kuskanook where a major boat ramp (Boswell BC) could not be effectively covered due to distance between this ramp and that at Kuskanook.

Table 7. Percent of total estimated rod hours recorded at the five access points on Kootenay Lake in 2011. Access point % of total rod hours 2011 Kaslo 15% Woodbury 25% Riondel 7% Balfour 34% Kuskanook 20%

5.4 Catch and Harvest

Catch and harvest estimates for the three main species are shown in Table 8. The 2011 survey attempted to segregate out angler effort targeted by species but the majority of angler responses were that they fished for “all” or both “rainbow trout and bull trout”. Catch statistics displayed in Table 8 are for all anglers that fished for all fish species. Total rod hours less “kokanee only” rod hours were used to calculate catch per unit effort (CPUE) for rainbow trout and bull trout. Meanwhile, anglers were far more specific if they were targeting kokanee, thus segregated effort (2,755 kokanee rod hours) was determined for those fishing explicitly for kokanee. Specific effort that was recorded as targeting either rainbow trout or bull trout can be found at the website: http://www.stat.sfu.ca/~cschwarz/Consulting/Kootenay/Y2010-2011/

Table 8. Catch statistics of the 2011 Kootenay Lake sport fishery based on the access & aerial surveys. Species Catch ±SE Release ±SE Kept ±SE Rainbow trout 15,995 1,408 9,846 963 6149 584 Bull trout 6,133 455 2,477 263 3,655 258 Kokanee 5,377 814 1,168 289 4,209 574

5.4.1 Rainbow trout

An estimated 16,000 rainbow trout were captured on Kootenay Lake in 2011 (Table 8). Of this total, almost 10,000 were released while nearly 6,200 were harvested (Table 8). This indicates almost 62% of the total catch was released. Division of total catch by total

14 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 effort results in an average CPUE of 0.08 for all rainbow trout. Similarly, use of total effort by total harvest results in an average HPUE of 0.03 for all rainbow trout. By far the greatest numbers of rainbow trout captured were during October and November followed by July (Figure 9). A most interesting characteristic of this fishery is that the highest angler effort occurred during the fall months yielding the highest catches and success rates (Figure 9). During these months, as well as December through to June, anglers target the larger size trout that are most frequently on the surface (Andrusak and Thorley 2011) foraging on kokanee. As summer advances some anglers still seek the larger trout that move to deeper (Andrusak and Thorley 2011), colder water but most switch to smaller trout using different (smaller) gear. These seasonal differences are an important aspect of the Kootenay Lake fishery.

The average size of rainbow trout caught in 2011 was ~55 cm with the sizes ranging from 23-93 cm (Table 9; Figure 10). No sampled rainbow trout exceeded 10 kg, a size often reached in previous years (Andrusak 1987) with the largest reported in 2011 at 9.8 kg. Recruitment to the fishery appears to occur at 30-35 cm based on the length frequency plot illustrated in Figure 10, similar to that observed by Andrusak and Parkinson (1984); Andrusak (1987) and Andrusak and Thorley (2011). As previously mentioned, most of the large rainbow trout are caught during the non-summer months (especially October & May) and when the trophy fishery is at its peak (Figure 10).

Table 9. Biological information collected on fish sampled at access points on Kootenay Lake in 2011. Lengths and weights are the mean values. Mean Length Range Mean Weight Species N (cm) ±SE (cm) (kg) ±SE Range (kg) Rainbow trout 326 54.5 0.97 23-93 2.54 0.14 0.15-9.8 Bull trout 219 56.9 0.64 28-87 1.99 0.09 0.2-7.7 Kokanee 7 25.8 1.39 21-32 0.16 0.04 0.1-0.3

5.4.2 Bull trout

Approximately 6,100 bull trout were captured in Kootenay Lake during 2011 (Table 8). Of this total about 2,500 were released while 3,655 were kept. This indicates 40% of the total catch was released, a much lower release rate than rainbow trout (62%). Division of total effort by total catch results in an average CPUE of 0.03 for all bull trout. Similarly, use of total effort by total harvest results in an average HPUE of 0.018 for all bull trout. The highest catch of bull trout occurred in the spring and fall months with relatively few caught during the summer and winter times (Figure 11). Oddly enough, the highest success rates occur during the late fall and especially the winter months of January and February even though effort is relatively low (Figure 11). Although bull trout can be caught in the surface waters usually in the spring (Andrusak and Thorley 2011), they are most often caught at depths between 20-50 m using down riggers. Bull trout

15 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 caught at these depths commonly have small kokanee (most likely ages 0+ and 1+ based on known size from trawl data) in their stomachs (K. Reed Kootenay Lake angling guide Nelson BC pers. comm.).

The average size of bull trout caught in 2011 was 57 cm with the sizes ranging from 28- 87 cm (Table 9; Figure 12). No bull trout exceeded 8 kg, with the largest reported in 2011 at 7.7 kg measuring a length of 87 cm. Despite this large bull trout, the remainder of the sample catch indicated very few fish exceeded 77 cm in length. Not surprisingly based on their life history (Fraley and Sheppard 1989; Downs et al. 2006), recruitment to the fishery doesn’t appear to occur until ~40 cm based on the length frequency plot illustrated in Figure 12, similar to that observed by Andrusak and Thorley (2011). Similar to the large rainbow trout, most of the large bull trout are caught during the non- summer months (Oct-May) and when the trophy fishery is at its peak (Figure 12).

5.4.3 Kokanee

An estimated 5,377 were caught on Kootenay Lake in 2011 (Table 8). Of this total, 4209 were kept with 1168 released for an approximate release rate of 22%. The majority of fishing for kokanee occurred during the summer months (June-August), however, a small number were caught in the fall months, mostly likely by-catch while fishing for rainbow or bull trout. Nevertheless, despite the majority of effort being directed to bull trout and rainbow trout, the estimate for effort directed at kokanee only seems uncharacteristically low. The most accurate portrayal of the kokanee fishery that is comparable with previous surveys considers effort directed specifically at kokanee only during the months June-August. During these months when kokanee were fully vulnerable to the fishery and anglers specifically fished for them (only) there was an estimated 2755 rod hours of ‘kokanee only’ effort, or 26,068 rod-hours of effort for all anglers including kokanee as a species sought. Catch for all anglers seeking kokanee for these months was 5,081 kokanee with 4,070 of these kept. Based on the raw data the CPUE when anglers’ targeted kokanee only was 1.26 fish per rod hours or 0.42 for those seeking kokanee and other species. Peak fishing in terms of catch and success was during July followed by August (Figure 13). Very few kokanee were sampled in 2011 (Table 9) but of those measured ranged between 25-30 cm with this very small sample having some large and small fish recorded usually caught with light fishing tackle on the surface (Figure 14). A more detailed analysis of kokanee size and probable age is discussed below in section 5.4.7.

5.4.4 Seasonal CPUE

The seasonal pattern for CPUE is shown in Figure 15 for all three species. The rainbow trout pattern indicates the highest CPUE during October-December with the lowest

16 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 rates during February-April and September. There was also a high success rate in July when smaller trout of recruitment size entered the fishery. The bull trout seasonal pattern was virtually constant throughout the year, slightly lower during the summer months. The kokanee pattern was zero until July-August and then falling to zero again by October.

5.5 2011 Survey Results compared Historic Surveys

5.5.1 Rainbow trout

It is known that at least two if not more rainbow trout stocks inhabit Kootenay Lake (Andrusak 2006; Andrusak and Thorley 2010) although it is generally believed or at least assumed that most trout > 50 cm are Gerrard rainbow trout (Andrusak and Andrusak 2006). A non-piscivore stock is known to spawn in some of the South Arm tributaries as well as some that spawn in Deep Creek, a tributary of the Kootenai River in Idaho (Andrusak 2006).

Creel census data is available for a number of years in the 1970s and 1980s albeit that a roving census method was used compared to the access point method used in 2011. The roving style census was conducted by dividing the lake into separate spatial zones with each of three zones sampled five days per month so lake wide coverage did occur but the effort estimates were not aided by aerial over flights (Andrusak 1987). This undoubtedly resulted in under estimates of catch and effort even though the data was adjusted upward by ~25% to account for missed anglers. The highest effort estimate prior to 2011 was in 1981 when ~170,000 rod hours were recorded, not much lower than the 2011 estimate (Table 10). The decline in effort from 1981 going forward initially reflected a downward trend in BCs economy but thereafter was related to the drastic decline in the West Arm kokanee fishery during the late 1980s (Redfish Consulting Ltd. 2001, 2002). Seven major resorts located at Balfour BC had been predominately supported by the West Arm kokanee fishery and the main lake fisheries but all seven closed when the West Arm kokanee fishery was closed. Anglers, especially non- residents, who fished the West Arm and the main lake simply ceased fishing on Kootenay Lake and this change accounts for most of the decline in effort not only on the West Arm but also on the main lake. The implementation of the KLRT stamp in 1987 and general decline in angler participation throughout BC during the last decade may also have contributed to the decline in main lake angler effort. The mean rainbow effort, catch and CPUE (excluding kokanee effort) for 1973-1986 was 114,170 rod hours, catch of 3,575 and CPUE of 0.03, much lower than the 2011 estimates of 198,678 rod hours, 15,995 catch and 0.08 CPUE. The 2011 increased effort estimate most likely reflects renewed interest in the Gerrard rainbow trout fishery that has been gradually improving throughout the 2000s as evidenced by the historically high spawner counts at Gerrard

17 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

BC (Figure 16). Today the spawner numbers are 2-3 times that recorded in the 1970s and 1980s. This increased effort is reflected in improved sales of KLRT licences during the last three years (M. Neufeld MFLNRO Fisheries biologist, Nelson BC, pers. comm.) Although the catch estimates appear to be far lower during the earlier decades there should be little doubt that the derived CPUEs are more comparable. The 2011 rate is nearly twice that recorded in any previous year of record. Further evidence of improved rainbow fishing is discussed below when the KLRT data is analyzed.

Table 10. Estimated rod hours, rainbow trout (RB) catch and CPUE on Kootenay Lake based on a roving creel census (1973-1986) and access point survey 2011. Data for 1973 to 1986 (Andrusak 1987). Year Directed Rod Hours RB Catch RB CPUE 1973 91,800 4,198 0.046 1974 74,610 2,814 0.038 1975 74,353 3,543 0.048 1976 104,099 4,668 0.045 1977 115,350 3,938 0.034 1978 123,922 3,414 0.028 1979 129,080 3,345 0.026 1980 127,483 4,381 0.034 1981 170,152 3,930 0.023 1982 159,471 4,169 0.026 1983 129,588 4,904 0.038 1984 110,675 3,106 0.028 1985 88,888 1,860 0.021 1986 98,903 1,779 0.018 2011 198,678* 15,995 0.080 *Total effort less kokanee effort (2,756 rod hours)

Length frequency distributions of harvested rainbow trout for 1966, 2004 and 2011 were plotted (Figure 17). Large size trout were present in the 1966 fishery but it is believed that the stock was recovering from population depletion due to large egg takes prior to 1960 that reduced spawner numbers as low as a peak count of 54 in 1957 (Irvine 1978) hence it is believed that few trout > 80 cm were available. Larger size trout (> 80 cm) were present in the 1970s and early 1980s with one trout caught that weighed 16 kg (Andrusak 1987). However a regulation change in 1987 (annual limit of 5 trout > 50 cm) completely changed the size distribution of trout harvested. i.e. prior to 1987 few fish of any size were released whereas after 1987 anglers began to release a high percentage of their catch in order to retain (future) larger trout. There are insufficient samples from the ultra-oligotrophic era (1980s-early 1990s) prior to nutrient additions to make comparisons with the more recent fertilized lake era but what is available is shown in Table 11.

18 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

A total of 326 rainbow trout were opportunistically sampled during the twelve month creel survey. Of this total 54% were > 50 cm (Figure 17). Total estimated number of harvested rainbow trout in 2011 was 6,149 therefore 3,320 trout > 50 cm were harvested assuming the sampled fish are representative. Based on the above analysis of probable size-at-age the harvested rainbows in 2011 by age were ~20% age 2+, 20% 3+, 18% 4+, 15% age 5+, 20% age 6+ and the balance ages 7+ and older ~ 7% or about 258 of the largest size trout (> 7 kg). The high percentage of age 6+ reflects preferential harvest of larger size fish. In most fisheries for rainbow trout the highest components of the catch and harvest are usually the smaller (younger) age groups.

Size-at-age from the 2011 data was unavailable at time of writing so data from Andrusak and Andrusak (2006) has been reproduced in Table 11 to ascertain probable size-at-age of rainbow trout caught during 2011. Gerrard juveniles enter the lake as age 1+ and 2+ ranging in size from 100-150 and >150 mm respectively (Andrusak and Thorley 2011). This data matches well with probable age determinations based on the length frequencies of the 2011 sport fishery data (Figure 10) where virtually no trout were captured at < 25 cm. Gerrard trout are believed to be initially recruited to the fishery at sizes > 25 cm and this appears to be the case in 2011 (Figure 10), i.e., it follows that the few 2011 trout caught in the size range of 25-35 cm are most likely age 2+. The mode at 40-45 cm is predominately represented by age 3+ while those within 45-55 cm represented mostly by age 4+ fish. Age 5+ fish are usually 60-70 cm and probably the largest of these tend to be the first time spawners at Gerrard. Ages 6+ are typically in the 75-85 cm size range while ages > 7 are usually found at sizes > 75 cm. Clearly it should be understood that there are overlaps in size between each age group and the smaller size rainbows are a mix of younger piscivores and non piscivores. Age determination from the 2011 scale samples will be instructive for determining if growth increased even more during recent years of fertilization than what Andrusak and Andrusak (2006) demonstrated with the 2004 sport fish samples.

19 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Table 11. Creel census data (length, weight, age, condition factor, all sizes) for Gerrard rainbow trout from 1966, 1988-1991 and 2003-2004 on Kootenay Lake. Data includes 95% CI for each variable. Data from Andrusak and Andrusak (2006). Creel Census Data Age 1966 3+ 4+ 5+ 6+ 7+ 8+ Sample size (n) 19 34 21 8 11 2 Mean Length (cm) 39.1 (± 8.74) 48.0 (± 7.25) 62.0 (± 7.87) 68.4 (± 7.11) 74.7 (± 5.09) 79.5 (± 0.71) Mean Weight (kg) 0.77 (± 0.56) 1.37 (± 0.75) 3.10 (± 1.15) 4.19 (± 1.31) 5.24 (± 1.62) 6.55 (± 2.2) Condition Factor (K) 1.12 (± 0.18) 1.13 (± 0.18) 1.23 (± 0.13) 1.27 (± 0.14) 1.23 (± 0.21) 1.31 (± 0.47) 1988-1991 3+ 4+ 5+ 6+ 7+ 8+ Sample size (n) 5 23 8 4 Mean Length (cm) 67.3 (± 11.1) 73.2 (± 5.9) 83.2 (± 6.4) 84.6 (± 5.3) Mean Weight (kg) 4.4 (± 2.3) 5.3 (± 1.2) 7.8 (± 1.4) 8.1 (± 1.1) Condition Factor (K) 1.34 (± 0.23) 1.35 (± 0.29) 1.36 (± 0.18) 1.34 (± 0.09) 2003-2004 3+ 4+ 5+ 6+ 7+ 8+ Sample size (n) 12 30 41 48 30 8 Mean Length (cm) 39 (± 10.4) 50.7 (± 11.1) 65.9 (± 11.9) 73.8 (± 9.7) 80.7 (± 7.6) 82.2 (± 8.04) Mean Weight (kg) 0.94 (± 0.6) 1.77 (± 1.2) 4.27 (± 1.9) 5.92 (± 2.1) 7.56 (± 1.8) 7.58 (± 2.6) Condition Factor (K) 1.34 (± 0.3) 1.16 (± 0.25) 1.37 (± 0.25) 1.41 (± 0.26) 1.42 (± 0.18) 1.31 (± 0.18)

*Note- age 2+ (n=2) for 2003-2004 data available but not displayed

The Fulton condition factor (K) has been calculated for all years (Andrusak and Andrusak 2006) where both length and weight data (Figure 18) were available for rainbow trout > 50 cm (Table 12; Figure 19). Sample sizes for most years were too small to apply a meaningful analysis to assess influence of kokanee abundance on rainbow trout condition (K) and the 1966 data was during near eutrophic lake conditions and there is uncertainty of randomness of the sampling. The relationship of predator condition factor and kokanee abundance is highly dependent on samples being taken during specific time periods since condition factor can vary considerably within a year. For example, samples of rainbow trout taken in May-June will likely have low (er) K values since some of these fish would be post spawners in poor condition compared to samples taken in the fall and winter months. Likewise, in-lake kokanee abundance can vary considerably from year to year depending on egg-to-fry survival at the Meadow Creek spawning channel. Unexplained decreases in Kootenay lake kokanee abundance that occurred in 2004 and 2005 followed by four consecutive years of high abundance (Sebastian et al. 2012) adds further doubt to the efficacy of using condition factor as a surrogate for determining response of predators to lake fertilization. Growth of Gerrard rainbow trout, spawner escapements and in-lake abundance and biomass of kokanee are deemed to be better metrics for determining success of lake fertilization. Based on available data, increased growth of Gerrard rainbow trout since fertilization began has been demonstrated by Andrusak and Andrusak (2006) and increased kokanee abundance and biomass have been demonstrated by Sebastian et al. (2012).

20 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Condition of Gerrard rainbow trout has been summarized in Table 12 and displayed in Figure 19, despite the sampling limitations previously mentioned. The pre-fertilization years are represented by creel data from 1981-1992, early fertilization data (1994-2004) from non-random angler interviews and most recent data (2010-2011) from the current census survey. Condition of all rainbow trout for all years is very good for all three time periods with mean K’s exceeding 1.27. It appears that shortly after fertilization commenced in 1992 rainbow condition (mean = 1.37) increased but the most recent data suggests a slight decline in mean condition. The 1994-2004 samples are probably positively biased due to deliberate selection for larger fish in the fall 2004 for fecundity that generally have higher K values than spring captured trout. There are insufficient samples for rainbow < 50 cm. It is noted that mean weights of 2011 harvested rainbow trout > 50 cm were considerably lower than those sampled in 2003-2004 and this may be problematic that argues for an update of the age at maturity and growth analysis conducted by Andrusak and Andrusak (2006).

Table 12. Mean length, weight, and calculated K (± confidence limits) factors for Kootenay Lake rainbow trout harvested during pre-fertilization era, early fertilization era and most recent years of lake fertilization. Mean Length Range Mean Range Years Size N (cm) (cm) Weight (kg) (kg) Factor (K) Range (K)

1966 >50cm 61 64.8 (± 1.33) 50-87 3.55(± 0.41) 1.2-8.3 1.21(± 0.02) 0.84-1.64 1981- 1992 >50cm 141 78.5 (± 1.41) 54-96 6.56 (± 0.34) 1.8-11.8 1.33 (± 0.03) 0.73-2.4 1994- 2004 >50cm 237 75.5 (± 1.25) 51-95 6.2 (± 0.29) 1.1-12.7 1.37 (± 0.03) 0.63-2.14 2010- 2011 >50cm 165 69.1 (± 1.49) 51-93 4.54 (± 0.31) 1.5-9.8 1.27 (± 0.03) 0.79-1.67

5.5.2 Bull trout

Kootenay Lake creel census data that included bull trout is available for a number of years from the 1970s and 1980s derived from the roving creel census of the day. As noted earlier the highest effort during that form of creel census design dates back to 1981 when ~170,000 rod hours were recorded, fairly close to the 2011 estimate (Table 13). The 2011 effort estimate most likely reflects renewed interest by anglers in catching a large Gerrard rainbow trout that that have been increasing in numbers during the 2000s and this in turn results in more bull trout being caught. The mean bull trout effort, catch and CPUE (excluding kokanee effort) for 1973-1986 was 114,170 rod hours, catch of 1,100 and CPUE of 0.01, much lower than the 2011 estimates of 198,678 rod hours, 6,133 catch and 0.03 CPUE. Although the statistics from the 1970s and 1980s appear to be far lower the CPUE should be quite comparable. If so, the 2011 rate is nearly three

21 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 times that recorded in any previous year of record, a fairly convincing indicator that the fishery has greatly improved from the pre-fertilization era. Further evidence of improved fishing is discussed below when the KLRT data is analyzed.

There were 219 bull trout sampled during the year-long census. Of this total 79 % were > 50 cm therefore this represents an estimated 4,845 bull trout caught > 50 cm. There is little that can be said about bull trout condition (K) since there are no data available from Kootenay Lake other than that collected in 2011. The mean K value for 2011 bull trout (n= 219) was 1.08 (Table 14) far less than the same sized rainbow trout. There may be some raw data from the 1960s in old files but this is uncertain and not work identified within this current contract.

Table 13. Estimated directed rod hours and bull trout catch on the main portion of Kootenay Lake based on a roving creel census (1973-1986) and access point survey 2011. Data for 1973 to 1986 (Andrusak 1987). Year Directed Rod Hours BT Catch BT CPUE 1973 91,800 464 0.005 1974 74,610 630 0.008 1975 74,353 882 0.012 1976 104,099 1,184 0.011 1977 115,350 887 0.008 1978 123,922 842 0.007 1979 129,080 1,077 0.008 1980 127,483 648 0.005 1981 170,152 427 0.003 1982 159,471 715 0.004 1983 129,588 665 0.005 1985 88,888 883 0.01 1986 98,903 666 0.007 2011 198,678* 6,133 0.03 *Total effort less kokanee effort (2756 rod hours) . Table 14. Mean length, weight and condition factor for harvested bull trout sampled during 2011. Mean Length Mean Weight Range N (cm) Range (cm) SE (kg) (kg) SE Mean K SE 219 56.67 28.0-87.0 0.69 2.01 0.2-7.7 0.09 1.08 0.01

5.5.3 Kokanee

There is a wealth of Kootenay Lake kokanee data primarily from Meadow Creek kokanee due to the spawning channel that has operated since 1967. The roving creel census data began to segregate directed kokanee effort and catch from rainbow and bull trout effort

22 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 and catch in 1968 as anglers were specifically questioned if they were fishing for kokanee only (Andrusak and Crowley 1978). Since the 2011 survey also segregates the effort data by species the 2011 directed kokanee effort of ~2800 rod hours and catch of~5100 is by far the lowest estimate of period of record even though the CPUE of 1.26 is very comparable with the average CPUE of 1.29 during 1968-1986 (Andrusak 1987). The 2011 kokanee catch and harvest over the full year was 5,377 and 4,209 respectively. Of the total catch, 5081 were estimated caught during June-August that represents 94% of the total for the year.

It is clear from Table 15 that main lake kokanee catch has declined precipitously since the early 1980s when harvest levels were close to 100,000. Arndt and Schwarz (2011) suggested that kokanee effort was related to mean size of harvested kokanee in Arrow Lakes, however analysis of mean size of Meadow Creek spawners (males being slightly larger than females) and Kootenay Lake directed kokanee effort indicates no relationship (Figure 20). There is little doubt that size of kokanee is a primary determinate for angler participation as demonstrated in the West Arm of Kootenay Lake kokanee fishery by Redfish Consulting Ltd. (2002). The seemingly contradictory data shown in Figure 20 is best explained as follows: anglers select for the largest fish when exploiting a population (Hilborn and Walters 1992) as demonstrated in the Lake Pend Oreille kokanee fishery by Rieman and Maiolie (1995) and Wood Lake fishery by Askey and Andrusak (2010). Review of the Meadow Creek data indicates there has been relatively little change in the average size kokanee over time (Table 15) with the range in spawner size in any given year quite narrow (Meadow Creek data on file MFLNRO office) but there will always be some fish larger than the median (right side “tail” of frequency distribution) and these are the most vulnerable to fishing. Therefore in any given year there are vulnerable kokanee available for anglers even though mean size is small. This explains the larger size kokanee in Figure 20 despite the smallest mean size of Meadow Creek kokanee for the period of record. Mean size of trawl captured fish (Figure 21) also shows little variation in size over the period of record (Kurota et al. 2011).

Based on the above rationale it is contended that size of harvested kokanee isn’t the only determinate of angler effort as many other factors related to angler preferences and socio-economics also influence fishing effort. In the case of the Arrow Lakes Reservoir fishery it is likely that low daily quota is a deterrent hence low annual effort for kokanee whereas on Kootenay Lake the decline in main lake kokanee angler effort was most likely due to the closure of the West Arm kokanee fishery in 1979 that extended for well over a decade. This fishery in the early 1970s attracted anglers from Idaho and Washington, Alberta as well as most parts of southern BC because the kokanee were very large resulting in some annual catches exceeding 100,000 (Andrusak 1981, 1987). Prior to the closure these anglers focused on West Arm kokanee but also tended to move out into the main lake and continue to fish for the smaller main lake

23 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 kokanee that had much higher daily quotas. Initially after the West Arm closure most of the effort shifted to the central part of the main lake with high effort and catches during the early 1980s. Kokanee fishing in the vicinity of Kaslo and Riondel in the 1980s also became very popular despite small sized kokanee based on Meadow Creek spawner size but effort in these fisheries declined by the late 1980s primarily due to a significant decline in non-resident participation (T. Jones Kaslo and Woodbury resort operator Woodbury BC pers. comm.). i.e. once the West Arm closure became an on-going annual event non-resident participation dropped off resulting in numerous resorts closing with the non-resident component of the angling population simply going elsewhere. The 2011 kokanee (only) anglers who were interviewed indicated during the summer months they had experienced high kokanee catch rates with some limit catches during the season even though they were the smallest on record.

The current status of Kootenay Lake kokanee in terms of abundance and biomass with comparisons between pre-fertilization and post-fertilization years has recently been updated by Sebastian et al. (2012). At present the in-lake abundance is at or near record levels with biomass in the fertilized era over fivefold higher than the pre-fertilization period of record (Figure 22).

Table 15. Estimated rod hours, main lake kokanee catch, CPUE and mean size of Meadow Creek kokanee males. Data based on a roving creel census (1973- 1986), Meadow Creek spawning channel and 2011 survey. Year Rod Hours Catch CPUE* Mean Length (cm) 1968 13,702 13,345 0.97 1969 8,604 6,696 0.78 21.4 1970 10,267 5,933 0.58 21.8 1971 9,674 11,684 1.21 23.3 1972 9,317 9,994 1.07 22.8 1973 36,254 16,912 0.47 23 1974 17,947 18,382 1.02 23.5 1975 12,363 17,095 1.38 21.5 1976 21,107 24,696 1.17 21.2 1977 23,418 32,236 1.38 21.9 1978 24,394 27,256 1.12 23.4 1979 18,300 13,700 0.75 22.6 1980 31,498 35,197 1.12 22.4 1981 61,554 90,366 1.47 21.6 1982 66,314 103,614 1.56 21.7 1983 41,666 67,320 1.62 21.1 1984 28,536 56,987 2 20.4 1985 20,301 26,244 1.29 20.6 1986 26,985 44,912 1.66 20.5 2011 2,756 5,081 1.26 20.0 * 2011 CPUE derived from raw data, not expanded data.

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5.6 Kootenay Lake Fishery Comparison.

Fisheries for pelagic piscivores similar to those in Kootenay Lake exist on very few BC large lakes and data from those are extremely limited. De Gisi (2002) summarized what lakes are known to support piscivorous rainbow trout and the number is quite small, less than 25 in all of BC. Nearby Arrow Lakes Reservoir (ALR) provides the best data for comparison with Kootenay Lake while some seasonal, limited data are available from Babine, Shuswap, Okanagan and Quesnel lakes. Except for Okanagan none of these lakes currently have comparable “trophy” size rainbow trout although in the past Shuswap lake did yield large size rainbow trout (i.e. > 7kg) and the ALR has produced some very large trout (Sebastian et al. 2000) that still are caught in lower numbers (Arndt and Schwarz 2011). There are no comparable bull trout fisheries, at least with data, except for the ALR. Shuswap Lake does have an angler survey similar to the KLRT that tracks trend data for the rainbow trout and lake char (Salvelinus namaycush) fisheries with bull trout a small contributor to the catch.

Methods of assessing large lake sport fisheries have varied considerably but the most common method has involved a roving creel census with some combination of access point interviews. With the exception of the ALR surveys described by Arndt and Schwarz (2011) there has not been a full annual census conducted on any of the above mentioned systems since the early 1990s primarily because a full survey is cost prohibitive. Okanagan Lake used to support very high effort levels in the late 1980s and earlier but most of this effort was directed at kokanee. This lakes’ kokanee population declined dramatically in the early 1990s resulting in a substantial drop in fishing effort (Andrusak et al. 2000). The rainbow trout fishery is quite comparable to Kootenay Lake and the CPUE was actually slightly higher. In fact all of the large lakes in APPENDIX 4- Creel Census on Other Southern BC Large Lakes that have rainbow trout data appear to have higher CPUE compared to Kootenay Lake at least until the results of 2011. The more recent surveys on the ALR indicate higher CPUE and catch until the 2011 survey. All of these large lake rainbow fisheries point to high daily effort levels as well as total annual effort that result in very low catch success rates. De Gisi (2002) and Andrusak (2005) both point out that despite the size of these large lakes the size of the spawning populations of piscivores are quite small (usually < 1000 per year) and are highly dependent on an abundance of kokanee.

Since the ALR and Kootenay Lake are the only systems to have contemporary annual creel surveys it is worth closer examination of their fisheries to understand the similarities and differences. The ALR information and data is taken from Arndt and Schwarz (2011). Both systems support year round fishing predominately by boat with Kootenay Lake in 2011 supporting ~2.5-3.0 times more angler effort than the recent ALR estimates. The target species for both fisheries are rainbow trout, bull trout and

25 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 kokanee. Both systems were impacted by upstream reservoirs that retained key nutrients that resulted in ultra-oligotrophic conditions that have been remediated through nutrient additions with Kootenay Lakes’ commencing in 1992 while fertilization of the upper basin of the ALR started in 1997. One substantial difference is that the ALR is comprised of two distinct basins connected by a shallow riverine section whereas the main part of Kootenay Lake is one very uniform body of water with a complex, shallow sill at the outlet.

Fishing for the target species on both systems is very similar; occurring year round but there is greater emphasis on bull trout on the ALR while on Kootenay Lake the focus is on Gerrard rainbow trout. Kokanee fishing is much more seasonal on both systems with most the effort occurring in July-August since age 2+ in September are mostly too small to catch (Figure 22).

5.6.1 Rainbow Trout: Kootenay Lake compared to ALR

Recognizing the difference between a roving survey conducted on Kootenay Lake until 1987 with access points surveys only on ALR until 2003 and there afterwards aided by aerial boat counts, some crude comparisons can be made between rainbow catch and CPUE. Kootenay Lake rainbow catch was relatively low during the 1970s and 1980s at <5,000 per year (Table 16). The same level of catch has been assigned to the ALR based on a number of reports (Sebastian et al. 2000) and professional judgement. These estimates for 1976-1997 are more likely to be high rather than too low. However, the 2011 Kootenay Lake estimate was three times greater at ~16,000 trout, some but certainly not all of the difference attributable to underestimations using the roving census method. The difference in catch between the two lakes during this era is believed to be primarily a function of angler effort with the Kootenay Lake level about 3 times that of ALR. The CPUE for both lakes has been fairly constant at < 0.10 trout per rod hour but the success rate on the ALR during the 1970s and 1980s was ~ ~0.07-0.08 while on Kootenay Lake it was much lower ranging from 0.02-0.05. The much more abundant large rainbow piscivores in Kootenay Lake most likely accounts for the lower CPUE (see below) and this notion is supported by Arndt and Schwarz (2011) observation that ALR rainbow piscivore trout catch increased for a short period from 2002 to 2005 resulting in lower CPUEs.

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Table 16. Rainbow trout estimated catch and CPUE for Kootenay Lake and ALR for those years with comparable data. Lake Years Catch CPUE Data Source Kootenay 1973-86 1,800-4,900 0.02-0.05 Andrusak 1987 Kootenay 2011 16,000 0.08 This report Arrow 1976-1979 3-5,000* 0.07 Sebastian et al. 2000 Arrow 1980-1989 3,-5000* 0.07 Sebastian et al. 2000 Arrow 1990-1997 3-5000* 0.09 Sebastian et al. 2000 Arrow 2003-2009 3,900-6,400 0.03-0.08 Arndt and Schwarz 2011 * Estimates based on Sebastian et al (2000) and author’s best judgement.

The major difference between Kootenay and ALR rainbow trout fishing is the size of trout captured. Average size of ALR rainbow trout caught and or harvested have been much smaller than on Kootenay Lake. The majority (60%) of harvested rainbows on ALR during 1991-1997 were less than 50 cm (Sebastian et al 2000); during 2008 and 2009 the harvest ranged in size 17-80 cm with means of ~39-40 cm. These sizes compare to a range of 23-93 cm and mean of ~54 cm (Table 9) for Kootenay Lake rainbows with 60% of the sampled catch > 50 cm (Figure 10).

5.6.2 Bull Trout: Kootenay Lake compared to ALR

Historically anglers on the ALR have preferred to catch bull trout more so than rainbow trout (Sebastian et al 2000). The older data on Kootenay Lake segregated effort for bull trout vs. rainbow and only ~20% of the total effort was directed at bull trout compared to 80% for rainbows (Andrusak 1987). Effort for bull trout on the ALR is arguably closer to 50%. In years past the catch levels on both systems have been approximately the same but success rate on ALR has been at least twice as high. However, using the same census method the annual catch on Kootenay Lake in 2011 increased to ~6,000 whereas on the ALR in 2009 it was only 2,900 (Table 17). The CPUE for bull trout on Kootenay in 2011 also increased to 0.03 per rod hour but still lower than all years on the ALR. Sebastian et al. (2000) felt that the ALR most likely supports more piscivorous bull trout than piscivorous rainbow trout.

Table 17. Bull trout catch and CPUE for Kootenay Lake and ALR for those years with comparable data. Lake Years Catch CPUE Data source Kootenay 1973-86 650-2,000 0.01 Andrusak 1987 Kootenay 2011 6,000 0.03 This report Arrow 1976-1979 2,000-3,500* 0.067 Sebastian et al. 2000 Arrow 1980-1989 2,000-3,500* 0.051 Sebastian et al. 2000 Arrow 1990-1997 2,000-3,500* 0.059 Sebastian et al. 2000 Arrow 2003-2009 2,600-3,800 0.06-0.08 Arndt and Schwarz 2011 * Estimates based on Sebastian et al (2000) and author’s best judgement.

27 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Unlike the size difference noted for rainbow trout between the two systems the bull trout in Kootenay and ALR appear to be about the same size (data on file MFLNRO) with the majority of harvested fish >50 cm.

5.6.3 Kokanee: Main Kootenay Lake compared to ALR

Because both Kootenay Lake and ALR are oligotrophic and are managed to produce large numbers of kokanee for the piscivores their mean size is regulated by density dependent growth, seldom achieving a mean size of 30 cm with most years mean size < 25 cm. The mean sizes of Kootenay Lake and ALR kokanee spawners have been tracked for at least the last three decades and summaries can be found in Schindler et al. (2010a, b). Kootenay Lake kokanee catches were very high despite small size of spawners in 1981 and 1982 when ~100,000 were caught each year but have since declined with the 2011 estimate the lowest on record (Table 18). The mean catch from 1973-1986 was ~33,000 (Table 18). In contrast, ALR kokanee catch has been much lower in recent years averaging ~8,500 with no annual catch > 15,100. However it is noted that Sebastian et al. (2000) reported a total ALR kokanee catch of nearly 60,000 in 1992. High catch rates > 1.0 per rod hour have been common on both systems and this was certainly the case for eleven years on Kootenay Lake and the ALR Andrusak 1987; Sebastian et al. 2000). There has been a somewhat surprising decline in CPUE for ALR kokanee during 2003-2009 falling to < 0.8 per rod hour (Arndt and Schwarz 2012 draft). During 2003-2009 anglers fishing for kokanee only experienced CPUEs ranging from 0.31 (2006) to a high of 0.78 (2004) (S. Arndt MFLNRO Fisheries biologist Nelson, BC pers. comm.).

Table 18. Mean kokanee catch and CPUE for Kootenay Lake and ALR for those years of comparable data. Lake Years Mean Catch CPUE Data Source Kootenay 1973-86 32,767 1.19 Andrusak 1987 Kootenay 2011 5,377 0.42-1.26 This report Upper Arrow 1976-1979 3284 1.06 Sebastian et al. 2000 Upper Arrow 1980-1989 8346 1.08 Sebastian et al. 2000 Upper Arrow 1990-1997 4841 1.53 Sebastian et al. 2000 Upper Arrow 1996-1997 727 0.47 Sebastian et al. 2000 Arrow 2003-2009 8,500 0.31-0.78 S. Arndt pers. comm.

5.7 KLRT Mail Out Survey

The KLRT survey provides a simple and cost effective method of obtaining valuable effort, catch and success rate trend information on the two primary recreational fisheries on the lake. A similar survey on Shuswap Lake (SLAS) has been conducted for over ten years and it has been the only way of monitoring this fishery (Andrusak 2011).

28 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Both surveys have been implemented due to the far higher cost of conducting either a roving or access point angler survey. Although mail surveys are relatively simple and comparatively inexpensive for their breadth of scope (Brown 1991; Pollock et al. 1994) they do have the potential for serious errors affecting the precision and accuracy of results (Brown 1991; Pollock et al. 1994, Renn and Bison 1996; DeGisi 1999). They also have the potential for serious non-response bias which would require substantial reconsideration of the survey design to estimate its accuracy, thus leading to an increase in overall costs. It is believed that the KLRT and SLAS survey biases are similar to the Steelhead Harvest Analysis (SHA) which is biased upward, inflating the effort and catch (De Gisi 1999). Despite these limitations, the importance of the mail surveys information used as a long term data set for fisheries management should not be underestimated, especially since no other cost effective alternative appears feasible. The primary value of the results of the mail-out survey if conducted over a long period of time is that they provide time series trend information.

One of the primary objectives of the 2011 creel survey was to understand, if possible, the relationship between the far more accurate 2011 survey estimates of effort and catch and the KLRT questionnaire results. Unfortunately the KLRT data has not been summarized beyond the 2007 data (Andrusak 2007). For the following analysis the raw data from the 2010-11 survey has been used to provide an approximate estimate of effort but this estimate will be revised on completion of the summary data by FLNRO.

5.7.1 Estimated Effort

This analysis attempts to compare angler effort between the KLRT survey results with the estimated effort from the 2011 access point survey. Eighty five percent of anglers responding to the KLRT survey during 1990-2010 indicate they are fishing for rainbow trout (data on file, FLNRO office, Nelson BC). The estimated mean annual angler effort from nineteen years of KLRT surveys (1987-2007, no data for 1995 & 1996) has been ~238,000 angler hours which is comparable with the 2011 survey estimate of ~199,000 h (Figure 23). The KLRT does not survey kokanee anglers thus the 2011 estimate was decreased by~2700 h directed at kokanee. In addition the KLRT does not survey those who did not purchase a KLRT stamp therefore the KLRT estimated effort should be adjusted upward by 22.4% based on the response of the 2011 anglers interviewed who stated they did not have a KLRT stamp. The survey most likely is positively biased since anglers are asked to recall what they did nearly a year earlier. There is little doubt that angler recall is suspect as indicated in the following example: KLRT anglers have reported an average of 5.5 h per angler day ranging from 5.03 h-6.13 h. The 2011 survey reported 4.98 h/angler day (Figure 23). The difference is most likely due to the KLRT data including boat travel time while fishing whereas the 2011 survey explicitly asked anglers the time they actually had their lures fishing (i.e., excluded boat travel time). The

29 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 same positive bias may well be involved in recall of number of days fished but there is no means of determining this. What the 2011 survey does indicate is that the mail-out survey effort estimate is likely high but probably < 10-20% higher.

Data from KLRT licence sales (FLNRO Nelson BC data on file) indicate that from 1987- 2007 angler composition consisted of 77% residents of BC, 15% non-residents of Canada and 8% non-resident aliens.

5.7.2 Estimated Catch

The estimated catch of rainbow trout by the KLRT survey has ranged from ~17,800- 44,600 with the average ~26,700. The 2011 survey estimate was nearly 60% lower at 15,995 (Table 19). The bull trout catch estimate is even less comparable: the KLRT survey estimated catch has ranged from ~9,000-16,700 with the average just over 12,000 (Table 19).. The 2011 estimate is about 50% lower. Such variation in these estimates, both effort and catch, places some doubt on the calculated CPUE shown in Table 19.

Table 19. Estimated catch and CPUE for Kootenay Lake rainbow trout and bull trout based on the KLRT survey (1987-2007) and the 2011 access point survey. Year Rainbow Catch Rainbow CPUE Bull trout Catch Bull trout CPUE 1987 17,829 0.085 1988 16,348 0.088 1989 20,483 0.107 1990 44,604 0.12 12,184 0.033 1991 27,530 0.105 9,401 0.036 1992 32,342 0.121 10,625 0.04 1993 36,297 0.141 10,312 0.04 1994 24,666 0.164 7,381 0.049 1995 26,547 0.178 10,410 0.07 1998 34,113 0.119 16,715 0.058 1999 36,609 0.135 15,334 0.057 2000 25,467 0.11 12,419 0.053 2001 21,377 0.111 10,887 0.057 2002 23,529 0.122 14,710 0.076 2003 22,969 0.076 12,484 0.041 2004 23,184 0.079 12,212 0.042 2005 17,979 0.078 9,030 0.039 2006 25,289 0.094 14,262 0.053 2007 29,416 0.145 14,974 0.074 2011 15,995 0.079 6,133 0.03

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Perhaps a more meaningful comparison between the two surveys can be made by estimating the catch and harvest of fish >50 cm. Since the majority of both species caught were > 50 cm and at that size approximate ≥ 2kg (cut off metric used in KLRT survey) it might be assumed that anglers probably have greater recall of the largest size fish that most KLRT anglers are seeking (i.e. legally permitted to keep only five rainbow trout > 50 cm for the year).

Assuming the rainbow trout sampled during the 2011 survey were representative then 54% of the total catch [15,995 was > 50 cm (8,637)] (Table 20). It follows then that the harvest (38%) of these trout > 50 cm was 3,282. These estimates are very close to the KLRT ten year average. Using the same rationale applied to the 2011 catch and harvest for bull trout (79% harvested) results in similar statistics being generated and comparable to the ten year average of the KLRT estimates (Table 20).

Table 20. Estimates of catch, released and harvested rainbow trout (RB) and bull trout (BT) > 50 cm (2 kg) based on the ten year average of KLRT data and that generated by the 2011 survey. RBT RB RB BT BT BT Survey Catch released harvested Catch released harvested 1998-2007 (average) 8,830 5,557 3,273 7,185 3,238 3,947 5,798- 3,639- 4,842- 2,034- 2,808- 1998-2007(range) 2,159-3,999 14,760 10,955 10,609 5,248 5,362 2011 survey (estimate) 8,637 5,355 3,282 4,845 1,502 3,343

In summary, the effort estimates between the KLRT survey and the 2011 survey do not appear to be comparable with the KLRT estimates with the latter most likely too high. However it does appear that the KLRT data for the larger fish is quite close to the estimates derived from the 2011 access point survey.

5.8 Survey Logistics and Limitations

The access point surveys and aerial boat counts were conducted successfully using twelve subcontractors plus two people utilizing a fixed wing plane to conduct boat counts. There were a few minor problems with the original design that can easily be improved for future surveys : certainly the assumption that Riondel/Crawford Bay was a good access point for the survey turned out to be incorrect as only 7% of the angler effort was estimated from this station. It was quite evident that far greater numbers of anglers returned to Balfour than one person could handle resulting in the interviewer(s) being overwhelmed during the spring and summer months. The necessity of having interviewers on station two hours after sunrise until dark needs reviewing with the data that is available given that the ratio estimator is used for estimating total effort. The

31 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 idea that secondary access points and shore anglers could be covered by the interviewers proved to be impractical as the interviewers were most often too busy or concerned about missing anglers to move from their primary location. This issue did not violate any of the requirements of the survey design because the air/access expansion ratio took this into account. However, lack of shore angler sampling and shore angler counts from the air did result in shore angling being excluded from the summary statistic . Assessing shore anglers proved to be virtually impossible given the stationary interviewers reluctance to check shore anglers any distance from their primary access point for fear of missing in-coming boats. This resulted in exclusion of shore angling data from the estimates. Transferring data from the interviews to an electronic file was occasionally problematic due to either poor hand writing or entry into the wrong column. After two months these issues were largely corrected. The weather was problematic for the winter flights as expected and most cancelled flights were re- scheduled by means of good communication between the contract monitor, the contractor and the sub-contractors who actually conducted the flight boat counts. One problem that was corrected was initially not having qualified backup people to conduct the boat counts.

Obtaining random samples of biological proved to be difficult. During the winter months few samples were obtained primarily because low catches per day were experienced hence few available samples. During the spring and summer the interviewers were often too busy to collect samples and or the harvested fish were already cleaned with head off. Sufficient rainbow and bull trout samples were obtained over the course of the year albeit unevenly over the seasons while kokanee samples proved somewhat elusive due to low catch. 6.0 RECOMMENDATIONS

6.1 Future surveys

It should be evident from this report that one year of census data does not provide great insight into the state of the fisheries since reference points are only available from the mid-1970s and mid-1980s. By the mid-1980s the lake was ultra-oligotrophic whereas today the lake is considered as productive oligotrophic. Hence it was difficult to make comparisons pre- vs. post-fertilization, especially since there was a paucity of comparable biological data from the pre-fertilization period. Future surveys should make two fundamental changes: firstly the Riondel station should be dropped and secondly to improve coverage at Balfour a small (~ 4.5 m) boat should be used to interview anglers returning to the plethora of docks and wharfs. Going forward, if aerial flights are too expensive, an analysis of the boat counts per stratum and boat counts via the ferry should be conducted to determine the percent of the lakes’ total count that

32 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011 the ferry is able to count. The following recommendations are made assuming a number of different funding scenarios:

1. Funding level similar to 2011

 Repeat the survey using the same methods and techniques.

 Delete Riondel as an access point.

 Provide a boat and station two interviewers at the Balfour access point.

 Conduct the same number of flights.

 Obtain representative samples of harvested fish to correlate with the KLRT data

2. Funding level approximately one half 2011 level

 Repeat the survey using the same methods and techniques.

 Delete Riondel and Kaslo access points.

 Station only one person at Balfour with a boat.

 Reduce winter time flights since estimator demonstrated low variability.

 Obtain representative samples of harvested fish to correlate with the KLRT data

 Utilize ferry boat counts to assist with determining effort.

3. Funding level at approximately one third of 2011 level

 Repeat the survey using the same methods and techniques but only in the central area of the lake

 Initiate interviews in late morning through to sunset.

 Delete Riondel and Kaslo access points.

 Station only one person at Balfour with a boat.

 Obtain representative samples of harvested fish to correlate with the KLRT data

33 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

 Utilize ferry boat counts to assist with determining effort.

 Utilize KLRT survey to determine area fished.

Authors note:

During the late stages of this report Schwarz (2012b) provided a far more detailed report that analyzed the 2011 survey methods and results. This report considers options to reduce costs while providing similar precision.

34 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

7.0 CONCLUSIONS

The 2011 angler survey on the main lake portion of Kootenay Lake was highly successful in providing scientifically defensible estimations of angler effort, catch and harvest of rainbow trout, bull trout and kokanee. The results essentially confirm that Kootenay Lake supports a distinct fishery for large size piscivores that is highly popular despite exceedingly low catch success rates. Anglers are willing to spend the time fishing for Gerrards provided they know there is a chance of catching a big trout. The results also indicate that the seasonal fishing effort pattern is quite different from most rainbow trout fisheries in that the highest effort is not during the summer months but rather in the non-summer months, especially October-December and May-June. The harvested rainbow trout and bull trout of large size (> 50cm) were in very good condition well above the K value of 1.0. Condition was not considered a good estimator of success of lake fertilization owing to seasonal variations and uneven samples over all seasons. The published reports on threefold increase in kokanee biomass since fertilization began and the astounding increase in numbers of Gerrard rainbow trout (Kurota et al 2011) and their growth are better indicators of success of lake fertilization.

The Kootenay Lake sport fishery is paramount amongst several other large lakes in southern BC owing to its ability to consistently produce large trout. Unfortunately most other large lakes do not have contemporary sport fishery data available for comparison. The single exception is the Arrow Lakes Reservoir that has good time series trend data throughout the 1990s and 2000s. This reservoir supports about one third the angler effort compared to Kootenay Lake and is known more for summer time fishing for smaller trout and kokanee. The ALR is far less accessible than Kootenay Lake and this may be a major reason for the difference in total angler effort. Also, far fewer large size rainbows are caught in the ALR compared to Kootenay Lake but the bull trout fisheries are very comparable both for size of fish and amount of directed angler effort. Historically Kootenay Lake supported far higher kokanee effort and catch than the ALR but the 2011 estimate places Kootenay Lake just within the range of the current levels of ALR kokanee catch and effort. The 2011 survey also provided some much needed up-to-date biological data that was compared with that obtained in the 1980s and 2004.

The survey should be repeated commencing in January 2013 and some suggestions are made as to what changes should be made. Meanwhile, the 2011 data should be compared with the 2011-2012 KLRT survey that is being assembled for mail-out at time of writing of this report. Future KLRT surveys should inquire as to primary location of fishing and primary access point.

35 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

8.0 REFERENCES

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Andrusak G.F. and Thorley J.L. (2010) Kootenay Lake Exploitation Study: Fishing and Natural Mortality of Large Rainbow Trout and Bull Trout. A Poisson Consulting Ltd. and Redfish Consulting Ltd. Report prepared for the Habitat Conservation Trust Foundation and Ministry of Forests, Lands and Natural Resource Operations (MFLNRO). HCTF Report No. CAT09-4-413. 20 pp. + app

Andrusak G.F. and Thorley J.L. (2011) Kootenay Lake Exploitation Study: Fishing and Natural Mortality of Large Rainbow Trout and Bull Trout. A Poisson Consulting Ltd. and Redfish Consulting Ltd. Report prepared for the Habitat Conservation Trust Foundation and Ministry of Forests, Lands and Natural Resource Operations (MFLNRO). HCTF Report No. CAT12-4-413. 47 pp. + app

Andrusak G.F. and H. Andrusak. 2012. Bull trout (Salvelinus confluentus) redd count surveys in select Kootenay Lake tributaries (2011) and recommendations for future surveys. Report prepared for Fish and Wildlife Compensation Program – Columbia Basin(Nelson, BC) by Redfish Consulting Ltd.(Nelson, BC). FWCP Report 56 pp. + app.

Andrusak, H. and M.A. Crowley 1978. Kootenay Lake Sport Fishery 1976-77 unpublished MS, Fisheries Branch, Nelson, BC

Andrusak, H. 1981. Kootenay Lake Sport fishery Statistics 1978-80. Fisheries Technical Circular No. 53 19181. Ministry of Environment.

Andrusak, H. and E.A. Parkinson. 1984. Food habits of Gerrard stock rainbow trout in Kootenay Lake, British Columbia. B.C. Ministry of Environment, Fish and Wildlife Branch, Fisheries Technical Circular No. 60. 1984.

36 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Andrusak, H. 1987. Kootenay Lake Sport Fishery 1984-86. Unpublished M.S., Fisheries Branch, Nelson, BC Report No. KO-19 31 p

Andrusak, H., and C. Brown. 1987. Kootenay Lake Fisheries Management Plan 1987-89. B.C. Ministry of Environment, 56 pp.

Andrusak, H., D. Sebastian, I. McGregor, S. Matthews, D. Smith, K. Ashley, S. Pollard, G. Scholten, J. Stockner, P. Ward, R. Kirk, D. Lasenby, J. Webster, J. Whall, G. Wilson, H. Yassien. 2000. Okanagan Lake Action Plan Year 4 (1999) Report. Fisheries Project Report No. RD 83. Fisheries Management Branch, Ministry of Agriculture, Food and Fisheries, Province of British Columbia

Andrusak, H. 2005. Kootenay Lake Gerrard Management Plan 2005. Contract Report by Redfish Consulting Ltd. for the Ministry of Environment Nelson BC.

Andrusak, H. 2006. A Review and Status Report of South Arm Kootenay Lake and Kooetnai/y River Adfluvial Rainbow Trout. Redfish Consulting Ltd. contract report prepared for the Kootenai Tribe of Idaho.

Andrusak, H., and G. F. Andrusak. 2006. Analysis of Gerrard rainbow trout size, age, fecundity and growth data. Final report submitted to the BC Ministry of Water, Land, and Air Protection, by Redfish Consulting Limited. Nelson, BC.

Anonymous (2010). Kootenay Lake Angler Survey: Draft Methods for Review. Document dated February 2010.

Arndt, S. and C. Schwarz 2011. Trends in Angling and Piscivore Condition Following Eleven Years of Nutrient Additions in Arrow Lakes Reservoir (Arrow Lakes Reservoir Creel Surveys 2003-2009). Technical report written for the Columbia Basin Fish and Wildlife Compensation Program Nelson BC.

Ashley, Ken, Lisa C. Thompson, David C. Lasenby, Laurie McEachern, Karen E. Smokorowski and Dale Sebastian.1997. Restoration of an Interior Lake Ecosystem: the Kootenay Lake Fertilization Experiment. Water Qual. Res. J. Canada, 1997 Volume 32 No. 295-323.

Ashley, K., L.C. Thompson, D. Sebastian, D.C. Lasenby, K.E. Smokorowski, and H. Andrusak. 1999. Restoration of Kokanee Salmon in Kootenay Lake, a Large Intermontane Lake, by Controlled Seasonal Application of Limiting Nutrients in Murphy, T.P. and M. Munawar 1999. Aquatic Restoration in Canada Backhuys Publishers, Leiden, 1999.

37 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Askey, P. and Andrusak G.F. (2010) Preliminary Stock Assessment Analyses of the Wood Lake Kokanee Fishery. Ministry of Environment, Penticton BC and Redfish Consulting Ltd. Report prepared for the Ministry of Environment, Penticton BC

Brown, T.L. 1991. Use and Abuse of Mail Surveys in Fisheries Management. American Fisheries Society Symposium 12:255-261.

Cartwright, J.W. 1961. Investigations of the Rainbow Trout of Kootenay Lake, British Columbia with Special Reference to the Lardeau River. BC. Fish and Wildlife Branch, Mngt. Publ. 7, 46p.

Cochran, W. G. (1977). Sampling techniques. Wiley. New York.

Daley, R.J., E.C. Carmack, C.B.J. Gray, C.H. Pharo, S. Jasper, and R.C. Wiegand. 1981. The effects of upstream impoundments on Kootenay Lake, B.C. Canada Inland Waters Directorate, Research Institute, Scientific Series, West Vancouver, British Columbia.

Dauk, P.C. and C.J. Schwarz. 2001. Catch estimation with restricted randomization in the effort survey. Biometrics 57, 461-468.

De Gisi, J.S. 1999. Precision and Bias of the British Columbia Steelhead Harvest Analysis. MS Contract Report for the Ministry of Environment and Parks Fisheries Branch Skeena Region Smithers BC. Skeena Fisheries Report SK122.

De Gisi, J.S. 2002 MS. Eutsuk Lake Rainbow Trout: Biology, Population Significance and Fishery Management. Draft Report prepared for BC Parks Skeena District, December 2002, 76 p.

Downs, C., D. Horan, E. Morgan-Harris, and R. Jakubowski. 2006. Spawning demographics and juvenile dispersal of an adfluvial bull trout population in Trestle Creek, Idaho. North American Journal of Fisheries Management 26:190- 200.

Fraley, J.J. and B.B. Shepard. 1989. Life history, ecology, and population status of migratory bull trout (Salvelinus confluentus) in the Flathead Lake and River system, Montana. Northwest Science 63: 133-143.

Hagen, J., and J. Baxter 2002. Rainbow Trout (Onchorynchus mykiss) escapement estimation at Gerrard 1961-2001: a comparison of peak count-based and area- under-the-curve methodologies. Draft contract report prepared for the Columbia-Kootenay fisheries Renewal Partnership.

38 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Hagen, J., and S. Decker 2009. Bull Trout Monitoring Plan for Kootenay Lake. Contract report prepared for the Fish and Wildlife Compensation Program-Columbia Basin, Nelson BC.

Hartman, G.F. 1969. Reproductive Biology of the Gerrard Stock Rainbow Trout. In: T.G. Northcote (ed.) Symposium on Salmon and trout in streams, H.R. MacMillan Lectures in Fisheries, Univ. of British Columbia: 53-67.

Hilborn, R. and Carl J. Walters 1992. Quantitative Fisheries Stock, Assessment Choice, Dynamics and Uncertainty. Chapman and Hall New York 570 p

Irvine, James R. 1978. The Gerrard rainbow trout of Kootenay Lake, British Columbia -a discussion of their life history with management, research and enhancement recommendations. BC Fisheries Management Report No. 72. March, 1978.

Koshinsky, G.D. 1972. Creel Census of Okanagan Lakes and Tributary Streams. Fisheries Research Board, Environment Canada. 1972.

Kurota, H., M.K., McAllister, E.A. Parkinson, N.T. Johnston and P.J. Askey. 2011. Progress report: Management reference points for kokanee and salmonids piscivores in large BC lakes. Province of British Columbia, Fisheries Project Report RD 133: Victoria, BC. Pp. 75.

Larkin, P.A. 1951. Summary of investigation conducted by the Fisheries Research Group, attached to the British Columbia Game Department in 1949. Report to the British Columbia Game Commission for 1949, pages 55-61.

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Moody, A., P. Slaney, and J. Stockner. 2007. Footprint impact of BC Hydro dams on aquatic and wetland productivity in the Columbia Basin. Report prepared by AIM Ecological Consultants Ltd. In association with Eco-Logic Ltd. and PSlaney Aquatic Science Ltd. for Fish and Wildlife Compensation Program, Nelson, BC

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39 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

O’Brien, D.S. 1999. The Duncan bull trout radio telemetry program. Prepared for Columbia Basin Fish & Wildlife Compensation Program, Nelson BC.

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Pearse, P.H. and M.E. Laub 1969.The value of Kootenay Lake sport fishery. BC Fish and Wildlife Br., Study Report No. 3, economics of Wildlife and Recreation. 58p.

Pollock, K.H., C.M. Jones, and T.L. Brown. 1994. Angler Survey Methods and their Applications in Fisheries Management. American Fisheries Society Special Publication 25.

Pope, K.L. and C.G. Kruse 2007. Condition. Pages 423-471 in C.S. Guy and M.L. Brown, editors. Analysis and Interpretation of Freshwater Fisheries Data. American Fisheries Society, Bethesda, Maryland.

Redfish Consulting Ltd. 2001. Upper West of Kootenay Lake Kokanee Habitat Assessment, Sport Fishery Analysis and Habitat Restoration Considerations that Would Contribute to Development of a Conservation Plan. Contract report for Fisheries Renewal BC and CKFRP

Redfish Consulting Ltd. 2002. West Arm of Kootenay Lake Kokanee Sport Fishery and Kokanee Food Habits 2002. Contract report for the Nelson Fisheries Branch of the BC Ministry of Water, Land and Air Protection, Nelson, BC.

Redfish Consulting Ltd. 2007. Kootenay Lake Rainbow Trout Survey Questionnaire Results 2003-2005. Contract report prepared for the Nelson Fisheries Branch of the BC Ministry of Environment, Nelson, BC.

Redfish Consulting Ltd. 2012. Shuswap Lake Angler Survey Questionnaire Results 2010- 2011. Contract report prepared for the Kamloops Fisheries Branch of the BC Ministry of Environment, Kamloops, BC.

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Rieman, B. E., and M.A. Majolie 1995 Kokanee Population Density and Resulting Fisheries North American Journal of Fisheries Management 15: 229-237, 1995.

Renn, J. and R. Bison. 1996. Shuswap Lake Angler Survey 1994. Ministry of Environment, Lands and Parks, Fish and Wildlife Branch.

40 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Schindler, E.U., D. Sebastian, H. Andrusak L. Vidmanic, S. Harris, G.F. Andrusak, F. Pick, L.M. Ley, P.B. Hamilton, D. Johner, P. Woodruff, M. Bassett and K.I. Ashley. 2010a. Kootenay Lake Nutrient Restoration Program, Year 16 (North Arm) and Year 4 (South Arm) (2007) Report. Fisheries Project Report No. RD 127, Ministry of Environment, Province of British Columbia.

Schindler, E.U., D. Sebastian, L. Vidmanic, H. Andrusak, J. Stockner, M. Bassett and K.I. Ashley. 2010b. Arrow Lakes Reservoir Nutrient Restoration Program, Year 9 (2007) Report. Fisheries Project Report No. RD 128, Ministry of Environment, Province of British Columbia.

Schwarz, C.J. 2010. Analysis of Preliminary Creel Survey and Recommendations for a Creel Survey of Kootenay Lake, British Columbia. Prepared for the Fish and Wildlife Compensation Program by Department of Statistics and Actuarial Science, Simon Fraser University, File 136-70.

Schwarz, C.J. 2012. Statistical methods used in the analysis of the 2010-2011 creel survey of Kootenay Lake, British Columbia. Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby BC.

Schwarz. C.J. 2012b. Potential modifications to the creel survey of Kootenay Lake, British Columbia. Prepared for the Fish and Wildlife Compensation Program by Department of Statistics and Actuarial Science, Simon Fraser University.

Sebastian, D., H. Andrusak, G. Scholten and L. Brescia. 2000. Arrow Reservoir Fish Summary. Stock Management Report – 2000. Province of British Columbia, Ministry of Fisheries.

Sebastian, D., R. Dolighan, H. Andrusak, J. Hume, P. Woodruff and G. Scholten 2003. Summary ff Quesnel Lake Kokanee and Rainbow Trout Biology with Reference to Sockeye Salmon. Stock Management Report No. 17. Province of British Columbia 2003.

Sebastian, D., H. Andrusak, G.F. Andrusak and T. Weir. 2012. in Schindler et al. 2012 draft report. Kokanee Responses To North Arm (Year 19) And South Arm (Year 7) Kootenay Lake Experimental Nutrient Additions

Shepherd, B.G. 1990, MS. Okanagan Lake management plan, 1990 - 1995. BC Min. Env., Recreational Fish. Progr., Penticton, BC.

Shepherd, B.G. 1994, MS. Angler surveys of Okanagan Main Valley lakes, 1982 - 1992. Fish. Proj. Rep. No. OK -17, Okanagan Sub-Reg., S. Int. Reg., Penticton, BC.

41 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Slaney, P.A. and H. Andrusak. 2003. Lardeau River Fish Habitat Assessments (2002) and Preliminary Gerrard Rainbow Trout Production Capability Modeling. PSlaney Aquatic Science Ltd. Contract Report for the Ministry of Water, Land and Air Protection, Nelson BC.

Thompson, L.C. 1999. Abundance and Production of Zooplankton and Kokanee Salmon (Oncorhynchus nerka) in Kootenay Lake, British Columbia During Artificial Fertilization. PHD Thesis University of British Columbia Vancouver BC. 252 p

Utzig, G. and D. Schmidt. 2011. Dam Footprint Impact Summary-BC Hydro Dams in the Columbia Basin. Contract report prepared for the Fish and Wildlife Compensation Program-Columbia Basin, Nelson BC.

42 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Figure 1. Kootenay Lake and creel survey access points. Riondel/Crawford Bay and Boswell/Kuskanook ramps were combined for field monitoring and data analysis.

43 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Figure 2. Winter-time (January-March) aerial boat counts at each stratum of Kootenay Lake. Note concentration of boats in the central area.

44 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Figure 3. Spring-time (April-June) aerial boat counts at each stratum of Kootenay Lake. Note heavy concentration of boats in the central area and more widespread distribution

45 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Figure 4. Summer-time (July-September) aerial boat counts at each stratum of Kootenay Lake. Note heavy concentration of boats in the central area as well as more boats throughout the lake, especially the extreme ends of the lake.

46 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Figure 5. Fall months (October-December) aerial boat counts at each stratum of Kootenay Lake. Note concentration of boats in the central area with fewer boats at extreme ends of the lake.

47 REDFISH CONSULTING LTD. Kootenay Lake Angler Creel Survey-2011

Figure 6. Estimated angler effort (rod hrs) December 2010, January-November 2011. Vertical bars indicate standard error.

Figure 7. Seasonal angler effort pattern expressed as percent of total rod hours per month 1983-1986, 2011.

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Figure 8. Estimated angler effort (rod h) and standard error bars for each month at each of the five access points.

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Figure 9. Total estimated catch of rainbow trout December 2010, Jan.-Nov. 2011. CPUE displayed on the secondary Y-axis illustrates the highest rates (and catch) were in the fall-winter months (Oct.-Dec.)

Figure 10. Length frequency distribution of angler caught rainbow trout in Kootenay Lake 2011 (n=326). Upper panel all rainbow trout captured in 2011, middle panel represents non-summer months (Oct-May n=197) and lower panel represents summer months (Jun-Sept n=129).

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Figure 11. Total estimated catch of bull trout Dec. 2010 - Nov. 2011. The CPUE displayed on the secondary Y-axis illustrates the highest rates were in the late winter months (Jan.-April).

Figure 12. Length frequency distribution of angler caught bull trout in Kootenay Lake 2011 (n=220). Upper panel all bull trout captured in 2011, middle panel represents non-summer months (Oct-May) and lower panel represents summer months (Jun-Sept).

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Figure 13. Total estimated catch of kokanee June-August 2011.. The CPUE displayed on the secondary Y-axis illustrates the highest rates were in July and August and is for anglers specifically targeting kokanee only.

Figure 14. Length frequency distribution of angler caught kokanee in Kootenay Lake 2011 (n=7). .

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Figure 15. Catch per unit effort (CPUE) for kokanee (KO), bull trout (BT) and rainbow trout (RB) from Kootenay Lake in 2011. Note scale change by panel.

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Figure 16. Gerrard rainbow trout spawner peak count from 1957-2011. Vertical lines represents commencement of North Arm (1992) and South Arm (2004) nutrient addition(data from MNFLRO file data).

Figure 17. Length frequency distribution of rainbow trout > 50 cm collected in 1966, 2004 and 2011 on Kootenay Lake. (1966 & 2004 data from Andrusak and Andrusak 2006).

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Figure 18. Length-weight relationship for rainbow trout (> 50 cm) on Kootenay Lake, pre dam (1966), pre-nutrient (1981-1992) and post-nutrient (1994-2011) eras. (data from Andrusak and Andrusak 2006).

Figure 19. Condition factor for rainbow trout (> 50 cm) on Kootenay Lake, pre-nutrient (1981-1992) and post-nutrient (1994-2011) eras.

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Figure 20. Scatter plot depicting relationship between angler rod hours and mean length of Meadow Creek male kokanee 1969-1986, 2011

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Figure 21. Size at age of kokanee on Kootenay Lake from 1985-2010. (Data from Sebastian et al. in Schindler et al. 2012 draft).

Figure 22. Trends in kokanee biomass density (kg/ha) for Kootenay Lake based on acoustic and trawl surveys 1985-2010. Dotted vertical lines indicate commencement of North and South Arm fertilization (Data from Sebastian et al. in Schindler et al. 2012 draft).

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Figure 23. Estimated KLRT angler rod hours, angler days and average hours per angler day (1987-2007; triangles) compared to the 2011 survey (redd circle).

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APPENDIX 1–Access Creel Angler Data Sheet

Kootenay Lake Access Creel Census Data Sheet page of Observer ______Access Point(s) ______Residence Codes: (R/NRC/NRA/Local) Date ______Time of Arrival ______Time of Departure ______Species Codes: (BT/KO/RB/MW) Circle day of week: Sun Mon Tues Wed Thur Fri Sat Weather______Wind____. (north 5km/hr)

Lake # of # of Finish Species Species Species # Guided Prov. KLRT ID Stratum Anglers Rods Start Time Time Sought Released # Released Kept Kept yes Residence State Ramp Y/N

1. Kaslo north; 2 Kaslo to Ainsworth; 3 Ainsworth to 20 Min Pt.; 4 20 Min Pt. to Boswell; 5. Boswell south; 6 West Arm

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APPENDIX 2–Access Creel Biological Data Sheet

Kootenay Lake Access Creel Census Biological Data Sheet page of Date: Sex Codes: (F/M/Undetermined) Maturity Codes: (M=mature; IM=immature) Age Data Codes (SC=scale, OTH=Otolith) ID Species kept Length (cm) Weight (kg) Sex Maturity Scale or Otolith COMMENTS

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APPENDIX 3. Creel Census Data Analysis

Statistical methods used in the analysis of the 2010-2011 creel survey of

Kootenay Lake, British Columbia.

Carl James Schwarz

Department of Statistics and Actuarial Science

Simon Fraser University

Burnaby, BC, V5A 1S6

[email protected]

2012-02-08

This document summarizes the statistical methods used in the analysis of the creel survey conducted from December 2010 to November 2011 on Kootenay Lake, British Columbia.

Briefly, the creel was sampled at 5 access points (Kaslo, Woodbury, Balfour, Queens Bay East, and Boswell) at randomly selected days within weekend and weekday strata from each month. During the sampled days, all angling parties returning to the access point were interviewed to determine the number and species of fish kept and released, the start and end time of the angling trip, and other variables. On some of the sampled days, an aerial survey was also conducted at approximately noon that counted the number of active boats on the lake. The number was counted once as the airplane flew out and again on the return flight.

All analyses in this report were done using SAS 9.3. Programs and results are available at: http://www.stat.sfu.ca/~cschwarz/Consulting/Kootenay/Y2010-2011/

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1. Estimates of catch and related variables

The survey is an example of an aerial-access survey as discussed by Pollock et al (1994) with non-randomized flight times. The interviews at the access point provide partial information about the total catch on the sampled day as other fishing parties may use different access points where creel clerks were not stationed. The aerial counts provide information on the fraction of the total effort that was sampled at the access point by comparing the number of active boats counted by the flight to the number of interviews that were active on the water during the flight time (determined by examining if the flight time occurred between the start and end of the trip) as outlined in Dauk and Schwarz (2001). For example, if 40 angling parties were interviewed on a date of which 30 were active during the overflight, and if the overflight counted 60 active parties, then it is estimated that only 30/60=0.50 of the total effort was interviewed and so the catch based on the 40 parties must be inflated by an (expansion) factor of 2 (1/0.5).

On some days, the aerial component was not done because of design or because it was not feasible to conduct the flight (e.g. weather conditions). For these days, multiple imputation was used to account for the missing data. In multiple imputation (MI) imputed values are chosen from a distribution of expansion factors that is believed to be applicable for the missing days (e.g. a normal distribution about the mean expansion factor). Several sets of data are generated using different imputed values. For each set of data, estimates of the total catch (and other variables) is found. The variation in the estimates over the replicated generated data provided information on how to adjust the standard error of the estimates for the imputation process.

The analysis of the creel survey first stratifies the survey year into monthly strata. Within each of these strata, days of the week were subdivided into two daytypes -- weekdays (Monday to Friday) and weekends (Saturday and Sunday). Holiday Mondays and other statutory holidays were also defined as “weekend” days. At least 2 days of each type are measured in each season and these replicates provide a design-based estimate of variance based on replicate daytype. This avoids having to make additional assumptions about the variation across days of the same daytype in strata when only one day of the daytype is sampled. It is assumed that days within each season-daytype stratum were selected at random.

It will be assumed that the days selected for aerial flights were a random sample of days selected for sampling, i.e. days with no aerial overflight are assume to be similar to day with aerial overflights.

The usual assumptions are made about data being collected properly (both at the access points and during the aerial surveys).

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Estimates are formed as simple expansion of the average response for a daytype within a season by the number of daytypes within that season. The standard error at this first step is based on that for estimating a total from a simple random sample as outlined in many books on sampling and demonstrated by Pollock et al (1994).

Step 1. Determine the expansion factor for the day.

Let Fstd represent the expansion factor for that day. If this day has and overflight, the expansion factor is found as:

å ActiveBoatFishing during a leg of the overflight legs Fstd = å number of angling parties active during that leg of the overflight active

More formally, as outlined in Dauk and Schwarz (2001), define dstdif = 0 /1 if the fishing party i in stratum s, day-type t, and sampling day d as not active/active during overflight leg f. For example, if the overflight leg occurred between 13:00 and 13:30, then the fishing party was active if the start and end times of their trip overlapped with 13:00- 13:30. Then the expansion factor for that day is found as:

å ostdf flights Fstd = å å d stdif interviews flights

where ostdf is the overflight count during leg f. If multiple legs were flown in a day, then the “active” status of the boat was determined for each leg. By summing over multiple legs in a day, the expansion factor is essentially an average over the aerial flights.

If this day does not have an overflight (missing data), the expansion factor is imputed using the mean and standard deviation of the expansion factor from all other days with overflights. [Preliminary plots indicated that the expansion factors did not vary much over the months or daytypes.]

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Step 1. Expand the observed response and compute the average response and standard deviation of the response over multiple days of each daytype in each season.

Let Ystd = å Ystdi be the response variable (e.g. total catch of species at all access interviews points) in stratum s, day-type t, and date d when summed over all interviews i for that day:

nst Number of days sampled of day-type t in season s.

1 Average (expanded) response for each season x Yst• = åYstd Fstd nst d day-type combination where nst is the number of days of that day-type within the stratum.

Standard deviation of (expanded) response over s(Y ) = (Y F -Y )2 (n -1) st• å xtd std st• st the days for each stratum x day-type combination

Step 1. Expand the average to estimate the total for the stratum-day-type combination.

Nmt Total number of days of day-type t in stratum s.

total(Yst ) = NstYst• Estimated total response for stratum s and daytype t.

2 Estimated standard error for the total response s(Yst • ) æ nst ö se[total(Yst )] = Nst ç1- ÷ for stratum s and day-type t. nst è Nst ø

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Step 4. Combined totals over day types within a stratum.

total(Ys•• ) = total(Ys,we ) + total(Ys,wd ) Estimated total response for stratum s.

2 2 Estimated standard error for se[total(Ys•• )] = seétotal(Ys,wd )ù + seétotal(Ys,we )ù ë û ë û total response for stratum s.

Step 5. Grand total over all strata.

total(Y••• ) = total(YDec•• )+ + total(YNov•• ) Estimated grand total over all strata

2 2 Estimated standard error for se[total(Y••• )] = se[total(YDec•• )] + +[total(YNov•• )] grand total over all strata

This procedure can be repeated for each variable of interest, e.g. number of fish kept, number of fish released, angler hours, rod hours, etc.

The multiple imputation method is outlined in Little and Rubin (2002, Section 5.4). In simple imputation methods, an imputed value is used for any missing expansion factor (e.g. the mean of the expansion factors). The “complete” data are then analyzed in the standard way. As long as the imputed value is an unbiased estimate of the missing value, the final estimates will still be unbiased, but the reported standard errors will be too small. Under multiple imputations, a model for the missing expansion factors is first determined. In this case, it seems sensible that the missing expansion factors come from the same distribution as the observed expansion factors. Then a total of M imputed datasets are created. In each of the M imputed dataset, a new imputed value is chosen for each missing value. For each of the “complete” datasets, compute the estimates of interest and the estimated variance (standard error squared) (e.g. estimated total

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ˆ catch), denoted as qi and Vi for i=1,… M respectively. The final estimate is the average of the estimates over the M “complete” datasets:

M 1 ˆ f = åfi M i=1

The final standard error combines the average variance from the “complete” datasets plus a correction term for the extra variation in the estimates over the different imputations:

M ˆ 2 M å(fi - f ) 1 M +1 i=1 SE (f ) = åVi + M i=1 M M - 1

The multiple imputation method requires the analysis of multiple complete datasets and some additional computations to roll-up the estimates from the multiple imputations but with modern software, this is relatively simple. A key advantage of the multiple imputation approach is that the model to generate the imputed values can be very general – it is not necessary to use the same distribution for all missing values if there is strong evidence that the missing values depends upon a covariate. For example, if the observed expansion factors showed a dependence upon weather variables, these weather variables could be used to impute a more appropriate expansion factor than the simple average.

2. CPUE

Only the interview data is required to estimate the CPUE. The CPUE was estimated for particular species and location/date as:

C CPUE = H where C is the total catch and H is the total rod hours for the location/date. A standard error could be computed for the CPUE using the formula for the standard error of ratio estimator in simple random sampling as:

1 1 2 SE(CPUE) = 2 (var(Ci ) + CPUE var(Hi ) - 2CPUE cov(Ci , Hi )) n H

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where n is the number of interviews; var(Ci )is the variance in the catch; var(Hi )is the variance in the rod hours; and cov(Ci , Hi )is the covariance between the catch and rod hours over the interviews for the location/date. However, this was done in this study as comparison of the CPUE are not of primary interest.

3. Angler profile

The angler profile (the proportion of angling parties that were active at each hour of the day) is computed by simply finding the proportion of all interviews where the interval between the start of angling trip and the end of the angling trip included all or part of the hour of interest. For example, if an interviewed angling party had a start time of 7:30 and an end time of 12:00, then it was considered active in the hours 7:00-8:00, 8:00-9:00, 9:00-10:00, 10:00-11:00 and 11:00-12:00. The approximate standard error can be determined from the standard error of a binomial distribution

pˆ (1- pˆ ) SE = h h n where p is the estimated profile at hour h. Again, the standard error was not found for h this survey.

References

Cochran, W. G. (1977). Sampling techniques. Wiley. New York.

Dauk, P.C. and C.J. Schwarz. 2001. Catch estimation with restricted randomization in the effort survey. Biometrics 57, 461-468.

Little, R.J.A. and Rubin, D.B. (2002). Statistical analysis with missing data, 2nd Edition. Wiley. New York.

Pollock, K. H., Jones, C. M. and Brown, T.L. (1994). Angler survey methods and their applications in fisheries management. American Fisheries Society Special Publication 25, Bethesda.

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APPENDIX 4- Creel Census on Other Southern BC Large Lakes

Rainbow Trout Bull Trout Rod Angler Rod Hour Lake Year Hours Days Day Catch Harvest CPUE Catch Harvest CPUE Survey Method Literature Shuswap 1990 147000 42045 3.5 9652 8216 0.09 66 66 N/A Access and Aerial Pankratz (1991) Okanagan 1971 188,000 64,000 11,000 11,000 0.06 N/A N/A N/A Access and Aerial Shepherd (1994) Okanagan 1988 221,000 14000 12,000 0.05 N/A N/A N/A Access and Aerial Shepherd (1994) Okanagan 1989 337,000 22000 18,000 0.07 N/A N/A N/A Access and Aerial Shepherd (1994) Sebastian et al Quesnel 1996 18000 Aerial (2003) Sebastian et al Quesnel 1997 21000 10-15K Aerial (2003) ALR 2006 74726 14576 5.1 5421 3635 0.07 3552 1817 0.05 Access and Aerial Arndt (2011) ALR 2007 82616 16809 4.9 5355 3787 0.06 3005 1821 0.04 Access and Aerial Arndt (2011) ALR 2008 72789 15190 4.8 5006 3714 0.07 2618 1437 0.04 Access and Aerial Arndt (2011) ALR 2009 77884 15412 5.1 4545 3215 0.06 2888 1621 0.04 Access and Aerial Arndt (2011) Kootenay 1985 88,888 1860 0.02 883 0.01 Roving Andrusak (1987) Kootenay 1986 99,000 1779 0.02 666 0.01 Roving Andrusak (1987) Kootenay 2011 201,500 44077 4.6 15995 6149 0.08 6133 3655 0.03 Access and Aerial This report

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