ARROW LAKES RESERVOIR CREEL SURVEY AND CONTRIBUTION …a100.gov.bc.ca/appsdata/acat/documents/r90/Arrow98-99FinalRepor… · ARROW LAKES RESERVOIR CREEL SURVEY AND CONTRIBUTION OF

ARROW LAKES RESERVOIR CREELSURVEY AND CONTRIBUTION OFHATCHERY PRODUCTION IN 1998

AND 1999

COMPILED BYSteven Arndt, M.Sc.

FORColumbia Basin Fish & Wildlife Compensation Program

18 June 2002

COLUMBIA BASINFISH & WILDLIFECOMPENSATION

PROGRAM

www.cbfishwildlife.org

Arrow Lakes Reservoir Creel Survey 1998-1999

Columbia Basin Fish & Wildlife Compensation Program i

Arrow Lakes Reservoir Creel Survey and

Contribution of Hatchery Production

in 1998 and 1999

Columbia Basin Fish and Wildlife Compensation Program103-333 Victoria St., Nelson, B.C. V1L 4K3

June 2002

Compiled by:

Steven Arndt, M.Sc.


Columbia Basin Fish & Wildlife Compensation Program ii

Executive Summary

Creel survey data were collected at five access points in 1998 and three in 1999.Data were summarized and extrapolated in accordance with the methods used inprevious years. Total estimated effort was 10,223 angler-days in 1998 and 9,139angler-days in 1999. Residents of British Columbia comprised 96% of the anglersin both years. Economic value of the fishery is estimated at over $1 milliondollars annually.

Kokanee harvests of about 10,000 were increased from 6,000 in 1997, and similarto the range reported for the early 1990s. The majority of the kokanee fisheryoccurred in the lower basin. Bull trout harvest levels of 790 to 1,340 were withinthe range of previous surveys; rainbow trout harvests (≈ 1800) were slightlylower than the long-term average. For bull trout and rainbow trout, the majorityof effort and harvest occurs in the upper basin. Burbot angling effort wasminimal and harvest level (<200 fish annually; 0.005 kg/ha) was about a tenth ofharvest levels reported for other lakes. Burbot catch-per-unit-effort was high.

Percentages of clipped bull trout and rainbow trout in the catch were similar toprevious years at < 3%, indicating very low survival to catchable size andhatchery contributions well below the target levels. Hatchery production isdiscussed in relation to recommendations from an earlier report (Winsby andStone 1996), studies that have been conducted since then, and assumptionsregarding limiting factors for the populations.

Limitations and assumptions of current creel methods are discussed and optionsfor improvement are presented with some cost approximations.


Columbia Basin Fish & Wildlife Compensation Program iii

Acknowledgments

I would like to thank creel technicians Alison Alder and her assistants (HailstormRidge Environmental Services), and Myles Crowley (Diversified Ova TechLimited) for their efforts in collecting the field data. Dr. Carl Schwarz (SimonFraser University) assisted with analysis of tag return data. Thanks to GrantThorp and Diane Koller (Hill Creek Hatchery) for providing information on bulltrout spawning from 1996-2001.

The report was improved by review comments from Bob Lindsay, John Bell,Grant Thorp, Beth Wright, Harald Manson, David Wilson and HarveyAndrusak, however, the author takes responsibility for the final version.

The Columbia Basin Fish and Wildlife Compensation Program is a joint initiativeof BC Hydro and the British Columbia Ministry of Water, Land and AirProtection to conserve and enhance fish and wildlife populations affected by BCHydro dams.


Columbia Basin Fish & Wildlife Compensation Program iv

Table of Contents

Executive Summary ............................................................................................................ iiAcknowledgments ............................................................................................................... iii Table of Contents ................................................................................................................. ivLists of Tables and Figures ................................................................................................. v

1.0 INTRODUCTION ...............................................................................................................1

2.0 METHODS ............................................................................................................................2

3.0 RESULTS ..............................................................................................................................4 3.1 Angler Origin ..................................................................................................................43.2 Effort, Harvest, and Size Distribution of Catch ........................................................6

3.2.1 Rainbow Trout .........................................................................................................133.2.2 Bull Trout ................................................................................................................133.2.3 Kokanee ....................................................................................................................133.2.4 Burbot ......................................................................................................................18

3.3 Hatchery Contribution to Harvest .............................................................................193.3.1 Bull Trout ................................................................................................................193.3.2 Rainbow Trout .........................................................................................................20

4.0 DISCUSSION AND RECOMMENDATIONS ..............................................................22 4.1 Effort and Harvest Estimates ......................................................................................22

4.1.1 Options for Future Monitoring ...............................................................................23 4.1.1.1 Recommendation ..........................................................................................25

4.2 Hatchery Production .....................................................................................................274.2.1 Bull Trout ................................................................................................................27 4.2.1.1 Recommendation ..........................................................................................294.2.2 Rainbow Trout .........................................................................................................29 4.2.2.1 Recommendations ........................................................................................30

5.0 REFERENCES .......................................................................................................................31

6.0 APPENDICES .......................................................................................................................331. Hill Creek Hatchery contribution to the harvest and total populations of

bull trout and rainbow trout in the Arrow Lakes reservoir in 1998 and1999 and approximate costs per fish.

2. Stocking records for Arrow Lakes reservoir from 1990 – 1997.3. Length and weight distributions of clipped rainbow trout in the 1998 and

1999 Arrow Lakes reservoir creel survey


Columbia Basin Fish & Wildlife Compensation Program v

List of Tables and FiguresTables

1. Time and access strata for the Arrow Lakes Reservoir creel survey in 1998 and1999 .....................................................................................................................................2

2. Summary of angler residence for the 1998 and 1999 Arrow Lakes Reservoircreel surveys by access point and month ......................................................................5

3. Estimated effort , harvest, catch, and CPUE by access point, month, andspecies for the 1998 creel survey of Arrow Lakes Reservoir .....................................7

4. Estimated effort, harvest, catch and catch per unit effort (CPUE) by accesspoint, month and species for the 1999 creel survey of Arrow Lakes Reservoir .. 10

5. Summary of the number and percent (0.95 confidence limits) of clipped bulltrout and rainbow trout in creel samples from 1998 and 1999 ................................19

6. Summary of location, clip, size, and probable brood year for clipped bulltrout from 1998 and 1999 creels ...................................................................................20

7. Summary of location, clips, size, and probable brood year for clipped rainbow troutfrom 1998 and 1999 creels.................................................................................................21

8. Comparison of Arrow Lakes Reservoir harvest rates for burbot to other lakesin British Columbia, Maine, and Alaska .....................................................................22

Figures

1. Map of Arrow Lakes Reservoir showing 5 access point used for the creelsurveys in 1998 .................................................................................................................3

2. Origin of Arrow Lakes Reservoir anglers in 1998 and 1999 ......................................43. Directed effort by species and access location in 1998 and 1999 ...............................64. Percentage of harvest at each of the surveyed access points for four species in

the 1998 creel survey of Arrow Lakes Reservoir ......................................................145. Species-directed effort by month for four species of fish in Arrow Lakes

Reservoir in 1998 and 1999 ...........................................................................................156. Length and weight frequency distributions of rainbow trout caught from

Arrow Lakes Reservoir in 1998 and 1999 ....................................................................167. Length and weight frequency distributions of bull trout caught from Arrow

Lakes Reservoir in 1998 and 1999 .................................................................................178. Length frequency distribution of kokanee from Edgewood, Shelter Bay, and

Nakusp sites in 1998 ......................................................................................................189. Length and weight frequency distributions for burbot caught in the 1998 and

1999 Arrow Lakes Reservoir creel survey ...................................................................1810. Graph and paired t-test results comparing Monday rod-hours to mean

weekday rod-hours of the same week for all available data from 1998 and1999 ...................................................................................................................................26

11. Number of spawned bull trout broodstock by sex at Hill Creek hatchery from1990 to 1998 ......................................................................................................................28


Columbia Basin Fish & Wildlife Compensation Program 1

1.0 INTRODUCTION

Arrow Lakes Reservoir is located between Castlegar and Revelstoke in the WestKootenay of British Columbia. It has a total surface area (upper and lowerbasins) of about 46,450 ha at full pool (elevation 432 m; Pieters et al. 1998), and isaffected by dams constructed at the reservoir outlet and upstream.

Hill Creek Hatchery and Spawning Channel were constructed with the goal ofcompensating for losses of salmonid spawning habitat due to Revelstoke andHugh Keenleyside dams. Construction of the spawning channel was completedin 1980; the hatchery was functional by 1983 (Thorp 1995). The facility is locatedabout 60 km north of Nakusp on the Upper Arrow Lake Reservoir.

The objectives of the facility are to annually provide 4,000 bull trout (Salvelinusconfluentus), 1000 trophy-size rainbow trout (Oncorhychus mykiss), 1,750 small-size rainbow trout, and 500,000 kokanee (O. nerka) to the sport fishery andspawning populations of the reservoir (Winsby and Stone 1996).1 Theseobjectives were derived from habitat-based estimates of the number of spawnerslost due to the dams. The spawning channel was designed primarily forproduction of kokanee, and the hatchery primarily for production of bull troutand rainbow trout. Funding for the facility is currently provided by BC Hydro(BCH) through the Columbia Basin Fish and Wildlife Compensation Program(CBFWCP), a joint initiative of BCH and the provincial government (Ministry ofWater, Lands, and Air Protection).

Creel surveys are included as part of the hatchery operations in order to provideinformation on the success of meeting the above production targets. The surveysalso provide a useful index of effort and harvest trends, as well as biological dataon the harvested species. This report documents the results of creel surveys in1998 and 1999 and discusses them in relation to hatchery objectives and previousharvest estimates. Recommendations are made with respect to modifying surveymethods for future years, and options for bull trout and rainbow troutproduction.

1 Release targets for fingerlings are much higher to account for the expected mortality from release to adultrecruitment (see Winsby and Stone 1996).



2.0 METHODS

The creel survey in 1998 had creel technicians at 5 access locations for 5 days permonth (Table 1, Figure 1). Sampling was randomized within the day typesshown in Table 1, except that days of fishing derbies are excluded. In 1999, twoof the locations (Fauquier, Edgewood) were discontinued after March due to ashortfall in funding for that year.

Table 1. Time and access strata for the Arrow Lakes Reservoir creel survey in 1998 and 1999.Fauquier and Edgewood locations were discontinued after March 1999.

Time Strata Weekend 2 days per monthMonday 1 day per monthWeekdays (not including Mondays) 2 days per month

Access Locations Upper ArrowShelter Bay boat ramp 5 days per monthNakusp government wharf 5 days per monthLower ArrowFauquier 5 days per monthEdgewood 5 days per monthCastlegar (mostly Scotties Marina) 5 days per month

Technicians were expected to stay at the access point for the duration of thefishing day, and the number of interviews is assumed to be the total effort for agiven access point and day. There are no boat counts on the lake. Anglers areinterviewed at the end of their trip. Information recorded includes length offishing trip, target species, species harvested and released, and angler residence.All harvested fish were examined for the presence of hatchery clips and tags.Length and weight measurements were recorded for some harvested rainbowtrout and bull trout (primarily in the upper basin locations).

Effort and harvest estimates were calculated for each access point and month bymultiplying the total effort (angler-hours, rod-hours) and harvest on sampleddays by the ratio of total days/sampled days for each day type. Estimates foreach day type were summed to obtain monthly totals for each access point. Fishclips were totaled for bull trout and rainbow trout, and 95% confidence limits forthe proportions of clipped fish in the harvest were calculated according toAgresti and Coull (1998) using the JMP 4.0 statistical program (courtesy of Dr. C.Schwarz, Simon Fraser University).

Catch-per-unit-effort (CPUE) was determined for each month/access/speciescombination by dividing the total fish caught by the total hours of directed effortfor that species. When more than one species was targeted by a party the total



hours were allocated to both species. For example, if a party reported 5 hoursangling effort seeking bull trout and rainbow trout, the 5 hours were included forboth species totals.

Figure 1. Map of Arrow Lakes Reservoir showing 5 access points used for the creel surveys in1998. Edgewood and Fauquier sampling sites were discontinued in 1999.



The five access locations in Table 1 include the majority of boat anglers, however,there are other less-used locations which are not sampled. Creel reports forprevious years have multiplied estimates (from the 5 access locations) by 1.25when projecting a total harvest, to compensate for missed boat access and shore-based anglers (Thorp 1995). In other words, it is assumed that the sampled accesspoints represent 4/5 of the total effort. This extrapolation was done in this reportas well, to enable comparison to previous creel reports, however, it should benoted that there are no data to determine the percentage of effort which does notoriginate from the sampled access points.

In 1999, sampling at the Fauquier and Edgewood sites was discontinued afterMarch leaving only three sampled access locations for the remainder of the year.For these sites in 1999, I added the 1998 estimates for April through December toallow an approximation of the 1999 total, before calculating the 25% increase.

3.0 RESULTS

3.1 Angler Origin

A total of 1,463 and 1,264 anglers were interviewed during the 1998 and 1999surveys respectively (including repeat contacts). Origins of anglers were identicalin those years, with 96% being BC residents and the remainder mostly from otherCanadian provinces (Figure 2). The Nakusp access point had a higherproportion of non-resident anglers than other access points, perhaps due to acharter fishing operation there. However, even in this location, non-residentscomprised less than 10% (Table 2).

BC Residents96%

Canadian Residents3%

Outside Canada1%

Figure 2. Origin of Arrow Lakes Reservoir anglers in 1998 and 1999.



Table 2. Summary of angler residence for the 1998 and 1999 Arrow Lakes Reservoir creelsurveys by access point and month. Categories are BC resident (RES), non-resident Canadian(NRC), and non-resident American (NRA).

1998 Shelter Bay Nakusp Fauquier Edgewood CastlegarMonth RES NRC NRA RES NRC NRA RES NRC NRA RES NRC NRA RES NRC NRAJ 3 0 0 33 7 0 4 0 0 0 0 0 11 0 0F 43 0 0 55 0 0 6 0 0 6 0 0 29 0 0M 39 0 0 23 5 0 4 0 0 0 0 0 27 0 0A 67 0 0 31 2 0 0 0 0 7 0 0 37 0 0M 49 0 0 41 2 0 0 0 0 3 0 0 49 0 2J 39 3 0 49 0 0 0 0 0 2 0 0 62 0 0J 10 0 0 27 5 4 6 0 0 24 0 0 99 1 1A 23 1 2* 77 13 5 10 0 0 11 0 0 68 1 0S 16 0 0 56 2 0 2 0 0 2 0 0 52 0 0O 7 0 0 44 6 0 2 0 0 5 0 0 28 0 0N 8 2 0 42 0 0 0 0 0 1 0 0 10 0 0D 0 0 0 46 0 0 0 0 0 0 0 0 4 0 0Total 304 6 2 524 42 9 34 0 0 61 0 0 476 2 3% 97.4 1.9 0.6 91.1 7.3 1.6 100. 0.0 0.0 100. 0.0 0.0 99.0 0.4 0.6

* Germany1999

Shelter Bay Nakusp Fauquier Edgewood CastlegarMonth RES NRC NRA RES NRC NRA RES NRC NRA RES NRC NRA RES NRC NRAJ 0 0 0 30 0 0 0 0 0 0 0 0 10 0 0F 6 0 0 42 0 0 0 0 0 3 0 0 29 0 0M 28 0 0 41 0 0 0 0 0 6 0 0 35 0 3A 50 0 0 43 0 0 Not surveyed for rest of year 36 0 0M 62 0 0 53 8 0 44 0 0J 3 0 0 73 1 2 48 0 3J 10 0 0 33 8 1 106 0 0A 22 0 2 43 5 0 85 0 1S 37 2 0 37 8 2 52 0 0O 20 0 0 28 0 0 48 0 0N 1 0 0 13 0 0 13 0 0D 0 0 0 20 0 0 8 0 0Total 239 2 2 456 30 5 0 0 0 9 0 0 514 0 7% 98.4 0.8 0.8 92.9 6.1 1.0 98.4 0.8 0.8 100. 0.0 0.0 98.7 0.0 1.3



3.2 Effort, Harvest, and Size Distribution of Catch

Total estimated effort in 1998 was 10,223 angler-days and 48,255 rod-hours with anestimated harvest of 1,338 bull trout, 1,884 rainbow trout, 10,115 kokanee and 175burbot (Lota lota) (Table 3). In 1999, estimated effort was 9,139 angler-days and 41,075rod-hours, with harvest estimates of 791 bull trout, 1,766 rainbow trout, 8,461 kokaneeand 122 burbot (Table 4). The upper basin was closed to kokanee harvest in 1999.

Economic value of the fishery, assuming an average expenditure of $115.52 per anglingday (B. Williams, Ministry of Water, Land, and Air Protection, personal comm.) was$1,180,960 in 1998 and $1,055,737 in 1999.

Rainbow trout and bull trout were targeted mainly in Upper Arrow (Shelter Bay,Nakusp) with a lesser amount of effort in the south end of Lower Arrow (Castlegar).Almost all of the kokanee effort occurred out of the Castlegar area. All burbot effortwas in the Upper Arrow. (Figure 3)

Shelter BayNakusp

FauquierEdgewood

Castlegar0

500

1000

1500

2000

2500

3000

Dire

cted

Effo

rt (h

ours

) Rainbow trout

Shelter BayNakusp

FauquierEdgewood

Castlegar0

500

1000

1500

2000

2500

3000 Bull Trout

Shelter BayNakusp

FauquierEdgewood

Castlegar

Location

0

400

800

1200

Dire

cted

Effo

rt (h

ours

) Kokanee

Shelter BayNakusp

FauquierEdgewood

Castlegar

Location

0

10

20

30

40 Burbot19981999

Figure 3. Directed effort (sum of sampled anglers) by species and access location in1998 and 1999. Note different numbers on y-axes.



Table 3. Estimated effort, harvest, catch and catch per unit effort (CPUE) by access point, month, and species for the 1998 creel survey of ArrowLakes Reservoir.

Estimated Effort Rainbow Trout Bull Trout Kokanee Burbot

Location MonthAngler-Days

Angler-Hrs

Rod-Hrs

Harvest Catch CPUEa Harvest Catch CPUEa Harvest Catch CPUEa Harvest Catch CPUEa

Shelter J 17.5 93.0 159.0 0 0 0.000 4.5 13.5 0.083 0 0 -- 0 0 --Bay F 217.5 936.5 1101.0 0 0 0.000 68 136 0.130 0 0 -- 0 0 --

M 234.5 1089.2 1181.2 4.5 4.5 0.005 87.5 100.5 0.075 0 0 -- 0 0 --A 403.0 2059.0 2194.0 57 101 0.035 126 174 0.082 0 0 -- 0 0 --M 245.0 1056.5 998.5 23 33 0.036 24 34 0.038 0 20 0.286 0 0 --J 190.5 877.5 877.5 48.5 81 0.098 20.5 24.5 0.030 4 4 0.051 0 0 --J 51.0 229.8 286.8 12 12 0.066 0 0 0.000 12 12 0.176 4 4 0.111A 148.0 459.0 459.0 15 15 0.176 0 0 0.000 50 50 0.435 0 0 --S 69.0 266.0 286.0 4 4 0.015 8 8 0.032 9 17 0.500 0 0 --O 53.0 248.0 248.0 4 4 0.036 0 0 0.000 0 0 -- 0 0 --N 50.5 247.0 247.0 5 14 0.097 9 13.5 0.097 0 0 -- 0 0 --D No data available -- -- -- -- -- -- -- -- -- -- -- --

Subtotal 1679.5 7561.5 8038.0 173 268.5 0.036 347.5 504 0.072 75 103 0.264 4 4 0.111

Nakusp J 250.5 1464.0 1611.0 18 18 0.011 89 128 0.081 0 0 -- 0 0 --F 272.0 1416.0 1568.0 12 12 0.010 68 72 0.043 0 0 -- 132 132 0.750M 189.5 1169.2 1199.2 5 15 0.017 39 63 0.051 0 0 -- 0 0 --A 177.0 973.5 1106.0 4 12 0.020 29 50 0.052 0 0 -- 0 0 --M 271.0 1106.5 1160.5 31 31 0.026 17 26 0.016 0 0 -- 0 0 --J 225.0 856.5 911.0 64.5 68.5 0.096 20.5 90.5 0.084 4 4 0.091 0 0 --J 221.0 746.5 765.5 62 62 0.074 8 8 0.016 49 49 0.190 4 4 0.125A 440.0 1650.0 1644.0 58 63 0.044 37 53 0.042 141 146 0.177 0 0 --S 299.5 1168.2 1338.5 168 193 0.156 8 8 0.009 8 8 0.333 0 0 --O 245.5 1297.2 1371.2 157 166 0.107 25.5 25.5 0.019 52 52 0.267 0 0 --N 220.0 1010.0 1082.0 36 45 0.050 58 63 0.057 5 5 0.029 0 0 --D 299.5 1323.5 1425.5 24 32 0.036 71 85 0.056 8 8 -- 0 0 --

Subtotal 3110.5 14181.2 15182.5 639.5 717.5 0.053 470 672 0.045 267 272 0.170 136 136 0.594



Table 3 (continued). Estimated effort, harvest, catch and catch per unit effort (CPUE) by access point, month, and species for the 1998 creelsurvey of Arrow Lakes Reservoir.



Angler-Hrs

Rod-Hrs


Fauquier J 27.0 63.0 63.0 0 0 0.000 0 0 -- 0 0 -- 0 0 --F 24.0 100.0 100.0 0 0 0.000 8 8 0.080 0 0 -- 0 0 --M 19.0 52.5 52.5 0 0 0.000 5 5 0.167 0 0 -- 0 0 --A No data available -- -- -- -- -- -- -- -- -- -- -- --M No data available -- -- -- -- -- -- -- -- -- -- -- --J No data available -- -- -- -- -- -- -- -- -- -- -- --J 36.7 111.7 111.7 8 32 0.316 0 0 -- 0 0 0.000 0 0 --A 50.0 180.0 220.0 0 0 0.000 0 0 -- 15 15 0.068 0 0 --S 8.0 30.0 60.0 0 0 0.000 0 0 -- 0 0 -- 0 0 --O 13.5 36.0 72.0 0 0 0.000 0 0 -- 0 0 -- 0 0 --N 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --D 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --

Subtotal 178.2 573.2 679.2 8 32 0.054 13 13 0.097 15 15 0.048 0 0 --

Edgewood J 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --F 40.0 248.0 248.0 0 0 -- 32 32 0.108 0 0 -- 0 0 --M 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --A 38.0 182.0 182.0 0 0 0.000 12 12 0.079 0 0 -- 0 0 --M 26.0 119.0 119.0 0 0 0.000 0 0 0.000 0 0 -- 0 0 --J 10.0 80.0 80.0 15 20 0.250 0 0 0.000 40 40 0.500 0 0 --J 129.0 355.0 355.0 44 52 0.542 0 0 -- 194 198 0.516 0 0 --A 76.0 162.0 162.0 0 0 0.000 0 0 -- 23 23 0.167 0 0 --S 8.0 24.0 24.0 0 0 -- 0 0 -- 0 0 -- 0 0 --O 35.0 244.0 244.0 22 22 0.187 18 36 0.667 0 0 -- 0 0 --N 8.5 42.5 42.5 0 0 0.000 0 0 0.000 0 0 -- 0 0 --D 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --

Subtotal 370.5 1456.5 1456.5 81 94 0.148 62 80 0.095 257 261 0.433 0 0 --



Table 3 (continued). Estimated effort, harvest, catch and catch per unit effort (CPUE) by access point, month, and species for the 1998 creelsurvey of Arrow Lakes Reservoir.



Angler-Hrs

Rod-Hrs


Castlegar J 57.5 230.5 248.5 0 0 0.000 5 5 0.020 0 0 -- 0 0 --(L. Arrow) F 164.0 506.0 544.0 8 8 0.050 44 44 0.044 0 0 -- 0 0 --

M 155.0 714.5 862.5 14 14 0.125 36 36 0.047 0 0 -- 0 0 --A 228.0 1019.0 1075.0 37 46 0.059 4 4 0.005 17 17 0.400 0 0 --M 297.0 1391.7 1497.5 53 63 0.104 8 8 0.018 932 932 1.075 0 0 --J 338.5 1226.2 1411.0 54 54 0.210 4 4 0.024 1301 1301 1.075 0 0 --J 629.5 2669.0 2924.0 111 111 0.346 4 4 0.020 3084 3084 1.180 0 0 --A 411.0 1538.5 1657.5 30 30 0.231 13 13 0.077 1158 1158 0.726 0 0 --S 328.0 1515.0 1934.0 221 221 0.244 0 0 0.000 971 971 0.750 0 0 --O 146.0 730.0 775.0 63 63 0.099 36 36 0.056 0 0 0.000 0 0 --N 47.0 170.0 195.0 15 15 0.081 15 15 0.071 15 15 -- 0 0 --D 38.0 123.5 123.5 0 0 0.000 9 9 0.077 0 0 -- 0 0 --

Subtotal 2839.5 11834 13247.5 606 625 0.142 178 178 0.033 7478 7478 0.985 0 0 --

Total for all sites 8,178 35,606 38,604 1,507.5 1,737 0.065 1,070.5 1,447 0.051 8,092 8,129 0.756 140 140 0.488X1.25 for missedeffort

10,223 44,508 48,255 1,884 2,171 1,338 1,808 10,115 10,161 175 175

a calculated as total fish caught/total hr of directed effort for the species; missing CPUE values indicate no directed effort for that species



Table 4. Estimated effort, harvest, catch and catch per unit effort (CPUE) by access point, month and species for the 1999 creel survey of ArrowLakes Reservoir. For Edgewood and Fauquier sites, data were available for January to March only so subtotals adjusted based on 1998 results(see Methods). Upper Arrow Lake reservoir was closed to kokanee harvest in 1999.



Angler-Hrs

Rod-Hrs


Shelter J 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --Bay F 28.0 154.0 228.0 0 0 0.000 16 16 0.065 0 0 -- 0 0 --

M 138.0 697.0 781.0 8 8 0.013 42 42 0.059 0 0 -- 0 0 --A 255.0 1501.5 1631.0 30 39 0.021 118 286 0.151 0 0 -- 0 0 --M 334.0 1747.5 1747.5 40 58 0.034 53 101 0.062 0 5 -- 0 0 --J 17.0 77.0 122.0 0 0 0.000 0 0 0.000 0 0 -- 0 0 --J 53.0 177.0 177.0 0 0 0.000 0 13.5 0.089 0 0 -- 0 0 --A 116.0 306.0 306.0 9 18 0.066 0 0 0.000 0 4.5 -- 0 0 --S 176.0 877.5 928.0 33 37 0.041 4 12 0.015 0 8 -- 0 0 --O 121.0 561.5 576.5 43.5 53.5 0.102 18.5 52.5 0.071 0 0 -- 0 0 --N 8.5 25.5 25.5 0 0 0.000 0 0 0.000 0 0 -- 0 0 --D 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --

Subtotal 1246.5 6124.5 6522.5 163.5 213.5 0.034 251.5 523 0.056 0 17.5 -- 0 0 --

Nakusp J 143.0 764.0 960.0 3 3 0.005 40 79 0.078 0 0 -- 0 0 --F 216.0 1308.0 1328.0 4 8 0.008 40 72 0.065 0 0 -- 0 0 --M 224.0 1113.0 1256.5 31 31 0.019 48 48 0.032 0 0 -- 0 0 --A 227.0 1007.0 1167.0 17 17 0.014 30 30 0.023 0 0 -- 0 0 --M 320.0 1677.5 1687.5 35 43 0.025 38 38 0.022 0 15 -- 0 0 --J 419.0 1753.0 1789.0 131 199 0.137 4 35 0.017 0 20 -- 0 0 --J 231.0 825.5 943.0 43 48 0.067 0 0 0.000 0 40 -- 31 50 0.917A 316.0 846.0 918.5 170 204 0.255 4.5 4.5 0.008 8.5 56 -- 27 27 1.500S 218.0 996.0 1058.0 113 117 0.109 13 21 0.020 0 4 -- 0 0 --O 156.5 685.0 738.0 97 139 0.187 17 21 0.022 0 0 -- 0 0 --N 80.0 295.0 323.0 11 11 0.018 0 4 0.018 0 0 -- 0 0 --D 124.0 591.5 716.0 8 8 0.021 8 27 0.041 0 0 -- 40 40 0.952

Subtotal 2674.5 11861.5 12884.5 663 828 0.068 242.5 379.5 0.031 8.5 135 -- 98 117 1.019



Table 4 (continued). Estimated effort, harvest, catch and catch per unit effort (CPUE) by access point, month and species for the 1999 creel surveyof Arrow Lakes Reservoir. For Edgewood and Fauquier sites, data were available for January to March only and subtotals were adjusted basedon 1998 results (see Methods). There was no angling at Fauquier from January to March because the boat ramp was not plowed (A. Alder,personal communication).



Angler-Hrs

Rod-Hrs


Fauquier J 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --F 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --M 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --A -- -- -- -- -- -- -- -- -- -- -- -- -- -- --M -- -- -- -- -- -- -- -- -- -- -- -- -- -- --J -- -- -- -- -- -- -- -- -- -- -- -- -- -- --J -- -- -- -- -- -- -- -- -- -- -- -- -- -- --A -- -- -- -- -- -- -- -- -- -- -- -- -- -- --S -- -- -- -- -- -- -- -- -- -- -- -- -- -- --O -- -- -- -- -- -- -- -- -- -- -- -- -- -- --N -- -- -- -- -- -- -- -- -- -- -- -- -- -- --D -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

Subtotalb 108.2 357.2 463.7 8 32 -- 0 0 -- 15 15 -- 0 0 --

Edgewood J 0.0 0.0 0.0 -- -- -- -- -- -- -- -- -- -- -- --F 12.0 60.0 60.0 0 0 -- 0 0 0.000 0 0 -- 0 0 --M 44.0 180.0 180.0 0 0 -- 0 0 0.000 0 0 -- 0 0 --A -- -- -- -- -- -- -- -- -- -- -- -- -- -- --M -- -- -- -- -- -- -- -- -- -- -- -- -- -- --J -- -- -- -- -- -- -- -- -- -- -- -- -- -- --J -- -- -- -- -- -- -- -- -- -- -- -- -- -- --A -- -- -- -- -- -- -- -- -- -- -- -- -- -- --S -- -- -- -- -- -- -- -- -- -- -- -- -- -- --O -- -- -- -- -- -- -- -- -- -- -- -- -- -- --N -- -- -- -- -- -- -- -- -- -- -- -- -- -- --D -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

Subtotalb 386.5 1448.5 1448.5 81 94 -- 30 48 0.000 257 261 -- 0 0 --



Table 4 (continued). Estimated effort, harvest, catch and catch per unit effort (CPUE) by access point, month and species for the 1999 creel surveyof Arrow Lakes Reservoir. For Edgewood and Fauquier sites, data were available for January to March only so subtotals were adjusted based onthe 1998 results (see Methods).



Angler-Hrs

Rod-Hrs


Castlegar J 53.5 250.0 310.0 0 0 0.000 5 5 0.018 0 0 -- 0 0 --(L. Arrow) F 192.0 872.0 916.0 0 0 0.000 4 4 0.007 0 0 -- 0 0 --

M 207.0 849.5 1002.5 0 0 0.000 39 39 0.040 0 0 -- 0 0 --A 154.0 676.0 732.0 8 8 0.015 0 0 0.000 124 124 0.805 0 0 --M 250.0 862.5 890.5 45 50 0.144 0 0 0.000 556 566 1.058 0 0 --J 254.0 1003.5 1053.0 61 61 0.138 0 0 0.000 838 838 1.158 0 0 --J 662.5 1906.0 1998.0 121.5 121.5 0.667 4.5 4.5 -- 2416 2488 1.201 0 0 --A 499.5 1579.5 1736.0 31.5 65.5 0.500 0 0 0.000 1775 1928 1.194 0 0 --S 233.0 765.5 867.0 81 81 0.277 0 0 0.000 596 596 0.915 0 0 --O 271.0 1103.0 1163.0 129.5 129.5 0.187 4 4 0.012 183 183 0.435 0 0 --N 59.5 322.5 430.0 20 20 0.132 42.5 54.5 0.132 0 0 -- 0 0 --D 59.5 279.0 442.5 0 0 0.000 9.5 9.5 0.018 0 0 -- 0 0 --

Subtotal 2895.5 10469.0 11540.5 497.5 536.5 0.137 108.5 120.5 0.027 6488 6723 1.080 0 0 --

Total for all sites 7,311 30,261 32,860 1,413 1,704 0.070 633 1,071 0.037 6,768 7,151 1.080 98 117 1.019X 1.25 for missedeffort

9,139 37,826 41,075 1,766 2,130 791 1,339 8,461 8,939 122 146

a calculated as total fish caught/total hr of directed effort for the species; missing CPUE values indicate no directed effort for that species

b for Edgewood and Fauquier, subtotals were adjusted by using 1998 monthly totals as estimates for April to December in 1999 because these access pointswere not surveyed for the whole year.



3.2.1 Rainbow Trout

Rainbow trout harvest in 1998 was split approximately equally between the upper andlower basin (Figure 4). Eighty-seven percent (1,507/1,737) of caught rainbow trout wereretained in 1998 and 83% (1,413/1,704) were retained in 1999. Effort peaked in latewinter/early spring and again in late summer/early fall (Figure 5). The early peak mayprimarily represent targeting of large piscivorous fish, and the late peak may represent thefishery for smaller littoral-dwelling rainbow trout. The CPUE tended to be higher in midto late summer (Tables 3 and 4).

Size distributions of measured rainbow trout were similar for the two years, with mostmeasuring from 25 to 50 cm in length and weighing < 1 kg. Rainbow trout over 5 kg werecaught in both years, but these represented a very small proportion of the total catch(Figure 6). Mean weight of measured fish was 756 g in 1998 and 650 g in 1999; this projectsto biomass harvests of 1,424 kg (0.031 kg/ha) and 1,148 kg (0.025 kg/ha) respectively.2

3.2.2 Bull Trout

About 75% of bull trout harvest occurred in the Upper Arrow (Figure 4). Overall, 74%(1,070/1,447) of the reported catch was retained in 1998 and 59% (633/1,071) in 1999. Effortfor bull trout peaked in late winter/early spring and was lowest in the summer (Figure 5).The CPUE tended to be highest from late fall to early spring, and was higher in the Upperthan the Lower basin (Tables 3 and 4).

Harvested bull trout measured from 35 to 95 cm in length (Figure 7) and weighed up toabout 5,500 g in both years (Figure 7). Mean weights were 1,948 g in 1998 and 2,042 g in1999; this projects to biomass harvests of 2,606 kg (0.056 kg/ha) and 1,615 kg (0.035 kg/ha)respectively.

3.2.3 Kokanee

Kokanee effort, CPUE and catch were much higher at the Castlegar (Lower Arrow) accesspoint, accounting for 93% of the harvest in 1998 (Figure 4). However, in 1999, kokaneeharvest was not permitted in the Upper Arrow due to concerns about declining spawningescapement. Effort and CPUE for kokanee peaked in the summer months in both years(Figure 5, Tables 3,4).

Mean length and weight of kokanee were 22.3 cm (Figure 8) and 147 g respectively, in1998; biomass harvest was 1,487 kg (0.032 kg/ha). Largest measured fish was 33 cm and450 g.

2 Example calculation: 0.756 kg/fish X 1,884 fish harvested = 1,424 kg harvested; 1,424 kg/46,450ha = 0.031 kg/ha



Rainbow Trout

Edgewood5%

Nakusp43%

Shelter Bay11%

Fauquier1%

Castlegar40%

Bull Trout

Edgewood6%

Nakusp44%

Shelter Bay32%

Fauquier1%

Castlegar17%

KokaneeEdgewood

3%

Nakusp3%

Shelter Bay1%

Fauquier0%

Castlegar93%

Burbot

Edgewood0%

Nakusp97%

Shelter Bay3%

Fauquier0%

Castlegar0%

Figure 4. Percentage of harvest at each of the surveyed access points for four species in the1998 creel survey of Arrow Lakes Reservoir.



Rainbow Trout

0

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19981999

Figure 5. Species-directed effort by month in Arrow Lakes Reservoir in 1998 and 1999. Allaccess locations are combined. Hours are the sum of sampled anglers (unextrapolated data).



Rainbow Trout 1998

20 30 40 50 60 70 80 90Length (cm)

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Rainbow Trout 1998

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Rainbow Trout 1999

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Rainbow Trout 1999

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Figure 6. Length and weight frequency distributions of rainbow trout caught fromArrow Lakes Reservoir in 1998 and 1999. Sample sizes are as follows: 1998 length n=20for lower basin, n=148 for upper basin; 1998 weight n=27 lower basin, 150 upper basin;1999 length n=0 lower basin, n=150 upper basin; 1999 weight n=1 lower basin, n=151upper basin).



Bull Trout 1998

30 40 50 60 70 80 90 100Length (cm)

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Bull Trout 1999

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Bull Trout 1999

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Figure 7. Length and weight frequency distributions of bull trout caught from ArrowLakes Reservoir in 1998 and 1999. Sample sizes were as follows: for 1998 length, upperbasin n=160, lower basin n=9; for 1999 length, upper basin n=96, lower basin n=0; 1998weight, upper basin n=161, lower basin n=26, 1999 weight upper basin n=96, lowerbasin n=15.



15 20 25 30 35Length (cm)

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Figure 8. Length frequency distribution of kokanee from Edgewood, ShelterBay, and Nakusp sites in 1998. (n=103)

3.2.4 Burbot

Estimated burbot harvest was less than 200 fish for the entire reservoir (Tables3,4), and almost all of it occurred from the Nakusp access site (Figure 4). Thisprobably reflects the efforts of a few individual anglers that occasionally target thespecies. Overall, there was very little directed effort for burbot, although CPUEwas high (0.5 – 1.0 fish/hr) for those anglers who did fish for burbot. Burbotangling occurred in winter and summer (Figure 5).

Mean length and weight of measured burbot were 60.6 cm and 1294 g respectively(both years combined due to small sample sizes), with fish up to 86.5 cm and 2268g (Figure 9). This projects to biomass harvests of 226 kg in 1998 (0.005 kg/ha) and158 kg in 1999 (0.003 kg/ha).

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Figure 9. Length and weight frequency distributions for burbot caught in the 1998and 1999 Arrow Lakes Reservoir creel survey (both years combined).



3.3 Hatchery Contribution to Harvest

The percentage of clipped fish in 1998 and 1999 was similar at about 1% - 2.8% forboth bull trout and rainbow trout, with 95% confidence limits between 0.3 and 7%(Table 5). Most clipped fish were caught at Shelter Bay or Nakusp.

Table 5. Summary of the number and percent (0.95 confidence limits) of clipped bull troutand rainbow trout in creel samples from 1998 and 1999.

Species Location 1998 1999Totalsampled

Numberclipped

Percent (0.95 C.I.)

Totalsampled

Numberclipped

Percent (0.95 C.I.)

Bull Trout Shelter Bay 47 0 0.00 48 3 6.25Nakusp 79 1 1.27 50 0 0.00Fauqier 3 0 0.00 0 0 -Edgewood 8 0 0.00 0 0 -Castlegar 31 0 0.00 20 0 0.00Shelter roving** 8 1 12.5 - - -

176 2 1.1 (0.3-3.1) 118 3 2.5 (0.9-7.2)

Rainbow Shelter Bay 33 2 6.06 32 1 3.13Trout Nakusp 116 4 3.45 118 3 2.54

Fauqier 2 0 0.00 0 0 -Edgewood 16 0 0.00 0 0 -Castlegar 114 2 1.75 94 0 0.00Shelter roving** 1 0 0.00 - - -

282 8 2.8 (1.4-5.5) 244 4 1.6 (0.6-4.1)

** Additional data obtained from a roving boat sampling done in Shelter Bay opportunistically in1998 by G. Thorp.

3.3.1 Bull trout

Using the clipped fish percentages (Table 5) and the 1998 and 1999 harvestestimates of 1,338 and 791 bull trout respectively (Tables 3,4), total hatcherycontribution to harvest would be 15 fish in 1998 and 20 fish in 1999.

Assuming an estimated total population of catchable-sized fish of 7,500 (Sebastianet al. 2000), the hatchery contribution to the total population would be 83 – 187fish, less than 5% of the hatchery target of 4000 spawners per year. Cost estimatesper harvested fish and per fish surviving to catchable size are shown in Appendix1.



Clipped fish originated from either the 1990 or 1993 brood years (Table 6). Exactdetermination was not possible because the adipose (AD) clip was used in bothyears, and size ranges overlap substantially for ages 5 and older. Table 6. Summary of location, clip, size, and probable brood year for clipped bull trout from 1998and 1999 creel surveys. Brood year was estimated based on clip and length-at-age curves inSebastian et al. (2000).

Year Location Clip Brood Year Length (cm)

Weight (g)

1998 Shelter Bay -- -- -- --Nakusp AD 1990 or 1993 68.6 3450Fauquier -- -- -- --Edgewood -- -- -- --Castlegar -- -- -- --

Shelter roving AD 1990 or 1993 54.0 1350

1999 Shelter Bay AD 1993 ? 47.0 1010Shelter Bay AD 1993 ? 46.0 1020Shelter Bay AD 1990 or 1993 57.0 1900Nakusp -- -- -- --Fauquier -- -- -- --Edgewood -- -- -- --Castlegar -- -- -- --Shelter roving -- -- -- --

3.3.2 Rainbow Trout

Clip combinations do not allow differentiation between the Gerrard rainbowprogram and the stocking of smaller rainbows. If both stocks are consideredtogether, clipped fish percentages (Table 5) and harvest estimates of 1,884 and1,766 (Tables 3,4) project to a hatchery contribution (Gerrard and smaller rainbow)of 53 fish in 1998 and 28 fish in 1999.

Extrapolating the percentages to an assumed population of 17,250 catchable-sizedfish (Sebastion et al. 2000) results in a hatchery contribution of 276 to 483 fish.Costs per harvested fish and per fish surviving to catchable size are estimated inAppendix 1.

It is generally assumed that fish over 50 cm are Gerrard stock; by this criteria,about half of the marked rainbows in 1998-99 were Gerrards (Table 7). The threerainbow trout with RM or LM maxillary clips may be from releases of age-2Gerrards (most Gerrards are released at age-1). Overall, it is difficult to ascertainthe brood year because of overlapping size-at-age for different brood years with



the same clip. Scale ages for these fish were not available at the time of writing.Stocking records are listed in Appendix 2.

Table 7. Summary of location, clips, size, and probable brood year for clipped rainbow trout from1998 and 1999 creels. Brood year was estimated based on clip and length-at-age curves inSebastian et al. (2000). It is assumed that fish over 50 cm were Gerrard stock and those under 50cm were Hill Creek stock. Also included is clip data collected from derbies in 1997 at threelocations (Shelter Bay, Nakusp, Castlegar). Clips are as follows: ARM=adipose/right maxillary;ALM= adipose/left maxillary; AD= adipose; RM= right maxillary; LM=left maxillary.

Year Location Clip Brood Year1 Length(cm)

Weight (g)

1998 Nakusp ARM 1994 G 51.0 1550ARM 1995 40.6 750AD 1997 ? 26.7 300AD 1997 34.0 450

Shelter Bay Unknown Unknown 34.0 400 AD/max2 1990, 1991 or 1993 G 72.4 4735

Fauquier -- -- -- --Edgewood -- -- -- --Castlegar RM 1993 G 58.5 2000

ALM 1996? -- 10001999 Nakusp LM 1992 G 73.7 4670 AD 1994 44.0 780

AD 1997 ? 24.8 350Shelter Bay RM 1993 G 68.0 3085Fauquier -- -- -- --Edgewood -- -- -- --Castlegar -- -- -- --

AD 1992 G 56.0 2000AD 1992 G 68.5 4000

1997 Derby creel(3 locations)

AD 1992 G 55.5 1800

1 G indicates fish assumed to be Gerrard stock2 could be ARM or ALM (side of maxillary clip was not recorded)



4.0 DISCUSSION AND RECOMMENDATIONS

4.1 Effort and Harvest Estimates

Harvest levels for bull trout in 1998 and 1999 (800 to 1,340 fish) are within therange of those reported in previous creel surveys (Sebastian et al. 2000). Forrainbow trout, the harvest of ≈1,800 is slightly lower than the long-term average(2,300) reported by Sebastian et al. (2000). Kokanee harvests of ≈10,000 are anincrease from ≈6,000 in 1997, and similar to the range reported for the early 1990s(Sebastian et al. 2000).

Harvest levels for burbot (< 200 fish) were slightly below the 1995 estimate (294fish; Thorp 1995) and about one tenth of those reported for other lakes in BritishColumbia, Maine, and Alaska (Table 8). The CPUE of up to 1.0 fish/hour is abouttwice as high as the highest CPUE observed in the Columbia Lake winter burbotfishery (Arndt 2001), and there is very little directed effort for burbot. Thissuggests that the species could likely sustain a higher level of harvest in ArrowLakes reservoir than it currently does.

Table 8. Comparison of Arrow Lakes reservoir harvest rates for burbot to other lakes inBritish Columbia, Maine, and Alaska.

Lake Size (ha) Harvest Period MeasuredFish/ha Kg/ha

Arrow Lakes reservoir 46,450 0.003 - 0.004 0.003 - 0.005 1998-1999Columbia Lake, BC 2,574 0.02 – 0.19 0.02 – 0.15 1995-2001Windermere Lake, BC 1,584 0.02 0.01 1996-1997Moosehead Lake, Maine1 30,308 0.07 – 0.23 0.03 – 0.17 1985-1999Moose/Tulsona Lakes, Alaska2 260 0.08 – 2.63 NA 1987-1997Susitna/Tyone Lakes, Alaska2 4,205 0.01 – 0.18 NA 1987-1997Lake Louise, Alaska2 6,519 0.04 – 0.15 NA 1987-1990Harding Lake, Alaska3 1,000 0.00 – 0.42 NA 1983-1998

1977-19921 data from Quinn (2000)2 data from Taube (2000) 3 data from Doxey (2000)

Estimates in this report have been compiled in accordance with previous estimatesto allow comparison, but as noted earlier, there are no data to determine the actualproportion of effort that is included in the 5 access points. For the Lower Arrow,sampling occurs mainly at Scotties Marina. However, there are two other accesspoints close by that have high use during peak periods (Syringa Park Marina, andthe provincial park boat ramp), therefore summer weekend effort may besubstantially underestimated in this area. Revelstoke Reach in the upper basin isalso reported to have a substantial seasonal angling use (K. Bray, CBFWCP,personal communication), and since most of these anglers are accessing from



Revelstoke, they are not detected in the current survey. Other less-used accesspoints such as Burton, Renata, and Deer Park are also not included in the survey.Many of these are not usable in the winter but are used in the snow-free months.

In addition, exclusion of fishing derbies under current sampling methods avoidsupward bias of the estimates. However, the avoidance of these days of highereffort likely causes a slight underestimation of total effort and harvest.

In summary, the access points used in this survey probably include the majority ofwinter effort, but may miss a greater proportion during snow-free periods. This islikely to have the effect of underestimating kokanee effort and harvest in the lowerbasin, where only one access point is monitored. Summer and fall rainbow troutharvest may also be under-estimated to a lesser extent. Bull trout harvest takesplace primarily during the winter months and is therefore less likely to besubstantially underestimated.

4.1.1 Options for Future Monitoring

The primary purpose of the creel survey is to evaluate the effectiveness ofprograms designed to compensate for dam impacts (i.e., bull trout and rainbowtrout hatchery production, kokanee spawning channel, lake fertilization starting in1999). Evaluation of hatchery production is based on marked fish in the creel (bulltrout, rainbow trout) and catch/harvest estimates (kokanee and other species).Fertilization effects can be evaluated by changes in catch and growth rates of fish.

Current creel methods have been relatively consistent since the early 1970s (B.Lindsay, personal communication), and therefore provide a valuable long-termindex of angling effort, CPUE, and harvest for sampled access points. However, thereare two weaknesses of current methods. First, as discussed above, the actualproportion of missed effort is unknown and consequently the extrapolations tototal harvest estimates cannot be considered reliable. Furthermore, the proportion ofmissed effort could change over time as new fisheries develop from un-sampledaccess points (for example, in Revelstoke Arm).

A second weakness of the current analysis is that it does not provide a measure ofuncertainty (i.e. confidence limits). Although this should not affect the validity ofthe index for detecting large changes in CPUE, size structure, and harvest over thelong term, it reduces the utility of the survey for detecting smaller changesbecause without confidence limits it is difficult to differentiate between actualfishery changes and sampling variability from year to year.



Some options for future monitoring are as follows.

1) Increase intensity of sampling (perhaps using roving boat counts and/or aerialcounts in conjunction with access sampling) and modify field and analysismethods (time and space strata) to allow coverage of the whole reservoir andestimates of effort and harvest with confidence limits. Cost for the existingaccess survey at only 3 locations is ≈ $32,500 annually (2001 costs), and presentfunding constraints would not permit a more intensive survey to be doneannually. However, it might be possible to do a more intensive survey atregular intervals, such as once every 3 years, with approximately the sameamount of annual funding summed over the interval. A hybrid accesspoint/overflight survey proposed for Kinbasket reservoir for 7 months wasestimated to cost $101,000 not including reporting and analysis (ARAConsulting 1994).

This option would have the advantage of providing more reliable estimates thatwould still track long term trends. However, with creel data only available atfixed intervals, year to year trends would not be tracked. There might also be adisadvantage for trying to detect certain year classes of stocked fish, and theresponse to management actions such as changes in the fertilization rate.

2) Attempt to address untested assumptions with periodic targeted studies atlower cost than the above. For example, a one-year creel survey of theRevelstoke Reach could provide data on the relative amount of missed effortand harvest in that part of the lake. Another example would be to do roving oraerial counts of boat and shore anglers over the whole lake on the same days asexisting access sampling to determine the total parties in relation to the numberat sampled access points. This could be done for one year, or perhaps only forthe summer months of one year. Flights from Castlegar to the north end ofArrow reservoir are estimated to cost approximately $475 per trip3 or $1,900 permonth for four flights (2 weekdays, 2 weekend days).

These studies would provide a better basis for the extrapolations used to arriveat whole lake harvest estimates using the existing access points. Costs wouldbe lower than the first option, but statistical rigour would not necessarily beimproved, depending on the specific methods used.

3) Leave field data collection methods as they currently are, but modify analysismethods to allow calculation of confidence limits. This option would make

3 Estimated time from Castlegar to Revelstoke and return is 3-4 hours in a Cessna 172 at a charge out rate of$135/hour (High Alpine Air, Castlegar, quoted January 28, 2002.



better use of existing data, and allow the long term index to be maintained. Itdoes not address the problem of an unknown amount of missed effort.

Current field collection and analysis methods use three day types (weekend,Monday, other weekday) and calculate estimates for each month. Comparisonof Monday effort to other weekdays for 1998-99 indicated no significantdifference between Monday effort and other weekdays (Figure 10, t-testP=0.33), therefore, in future analyses it is only necessary to use two daytypes:weekdays including Mondays, and weekend/holidays4. Inclusion of theMonday samples with other weekdays would simplify calculation ofconfidence limits. (Currently there is no replication of the Monday day typeeach month.) A database should be developed for storing and analyzing data.Statistical methods such as those in Pollock et al. (1994) should be applied to theanalysis. Various options could be tested (e.g. using seasonal time stratainstead of monthly) to provide narrower confidence limits for the estimates.

4.1.1.1 Recommendation

In the short term, a database should be developed for electronic storage andanalysis of data, and a method determined to allow calculation of confidencelimits (Option 3). These can be done at no additional cost to the program otherthan allocation of staff time. The Monday stratum can be eliminated to simplifyanalysis. CBFWCP should consider issuing a request for to determine the cost ofOption 1. Option 2 could be implemented at any time if funding is available.

4 The reason Mondays were separated in old census programs was because most stores were closed onMondays and anglers tended to fish more on this day than other weekday (H. Andrusak, personalcommunication).



MeanWkday By Monday

-25

0

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Paired t-Test

Paired t-Test

Monday - MeanWkdayMean DifferenceStd Errort-RatioDF

0.946232.2063980.428857

83

Prob > |t|Prob > tProb < t

0.66910.33460.6654

Figure 10. Graph and paired t-test results comparing Monday rod-hours to meanweekday rod-hours of the same week for all available data from 1998 and 1999.Analysed using Systat 9 for Windows.



4.2 Hatchery Production

Low percentages of clipped bull trout and rainbow trout in both 1998 and 1999 areconsistent with results in previous years. The sample sizes of examined fish arerelatively large (>100 for bull trout and ~250 for rainbow trout) and giveconfidence limits that are adequate to assess the stocking program (Table 5).Furthermore these data are consistent with previous years, giving addedconfidence that they accurately reflect the proportion of hatchery fish in the catch.

4.2.1 Bull Trout

The long-term trend for hatchery bull trout (<2% of catch up to 1997, Sebastian etal. 2000) indicates that survival rates of stocked fish in the reservoir are very low,resulting in negligible recruitment to the population and extremely high costs perfish surviving to catchable size (Appendix 1). The low incidence of marked bulltrout in 1998 and 1999 is of particular interest because large numbers of markedjuveniles were released from the 1990 to 1993 year classes and fish surviving fromthese releases should have recruited to the fishery starting in 1996 (Winsby andStone 1996). The 1998-99 creel surveys detected at most three fish from the 1990release (55,671 yearlings), none from the 1991 (171,386 yearlings) and 1992 (61,664yearlings; 9,948 two-year-olds) releases, and five from the 1993 release (103,506yearlings; 5,000 two-year). Another possibility is that fish of the 1991 or 1992releases (adipose + maxillary) were mis-identified due to failure to detect themaxillary clip, in which case the 1990 and 1993 year class percents would bereduced.

The reason for the low survival rates of hatchery fish after release is not known.One possibility is that it is related to lower nutrient levels and food availability inthe reservoir after upstream dam construction. Hill Creek bull trout releases beganin 1984, and the diet of bull trout in the reservoir is comprised almost entirely ofkokanee (Sebastian et al. 2000). If kokanee numbers are considered a measure offood availability, trends do not provide strong support for a food limitationhypothesis for the early years, although this may have been a factor later on.Kokanee spawning run estimates do not decline substantially from pre-Revelstokedam estimates until 1992. Likewise, angler CPUE for kokanee was generallyhigher from 1984 to 1992 than it was prior to Revelstoke dam (Sebastian et al.2000).

Sebastion et al. (2000, p. 34) note that there appears to be no long-term downwardtrend in the bull trout fishery since the construction of the dams (although therewas a brief period of low catch and CPUE from 1984 to 1986). They suggest thatthe level of exploitation is too low to cause a change in the statistics even though



the actual abundance is probably less than pre-dam construction. However, theyalso note that anticipated bull trout losses were based on the assumption thatstream habitat was the most likely factor limiting bull trout production. Thisassumption was a reasonable starting point given the information available at thetime, however the lack of a downward trend and anecdotal reports of improvedfishing following lake fertilization suggest that lake productivity may be a moreimportant limiting factor. If lake productivity is limiting, fertilization should helpaddress that factor.

Another consideration is the possibility of negative effects of hatcherysupplementation on the existing population genetics. It has not been possible forthe hatchery to meet broodstock targets of 150 – 200 fish for most years since 1983(Winsby and Stone 1996), and in fact numbers of spawned fish have declined tovery low numbers in recent years (Figure 11). Consequently, if production andsurvival targets were met, there could be a reduction in genetic variability of bulltrout in the reservoir due to a bottleneck effect (very small number of individuals

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Figure 11. Number of spawned bull trout broodstock by sex at Hill Creek hatcheryfrom 1990 to 1998 (data up to 1995 from Thorp 1995; for 1996-1998 from G. Thorp, D.Koller, pers. comm.). Numbers above bars indicate the effective breeding population(Ne) for each year (Kapuscinski and Jacobson 1987). Broodstock collection occurredonly at Hill Creek in 1995 and 1997, but at multiple sites in other years. Broodstockcollections were discontinued after 1998.



producing subsequent year classes). These concerns were raised in an earlieroptions report (Winsby and Stone 1996) which recommended that geneticdifferences among existing spawning populations be assessed. Results of theassessment indicate some genetic differences among the tributaries (Latham andTaylor 2001) that could be compromised by a hatchery program that mixesbroodstock from different streams. Hatchery releases to date have not negated thedifferences among tributaries, presumably because of the extremely low numberof hatchery fish surviving to breeding size.

From a broader ecosystem perspective, it appears likely that some bull trout thathistorically would have migrated freely into the Arrow Lakes have been isolatedin upstream Kinbasket and Revelstoke reservoirs. Thus there may be more bulltrout in the Upper Columbia drainage now than there was prior to damconstruction, particularly if numbers in the Arrow Lakes reservoir have remainedstable.

4.2.1.1. Recommendation

The CBFWCP Fisheries Technical Committee should reconsider the efficacy ofstocking bull trout in Arrow Lakes Reservoir5. Bull trout populations appear stablewith current recruitment coming almost entirely from natural reproduction. Thereis also a possibility of the hatchery having deleterious effects on the geneticstructure of the population and the number of spawners in streams used forbroodstock collection. Lake fertilization, starting in 1999, may increase in-lakegrowth and survival of natural recruits. This should be evaluated throughongoing creel surveys. An assessment of juvenile production from tributarystreams would contribute to understanding the dynamics of bull trout in thereservoir.

4.2.2 Rainbow Trout

Although hatchery Gerrard and smaller Arrow Lakes rainbow trout cannot beseparated by clips alone, it is more likely that fish over 5 pounds (2.25 kg) areGerrard stock. Previous reports have suggested that stocked Gerrards comprise arelatively high percentage of the larger rainbows caught (Winsby and Stone 1996,Sebastian et al. 2000). Scale collections tend to represent these larger fish becauseinstructions have specified that scales be collected from all rainbows over 5pounds and all clipped fish. In 1994, clipped fish made up 29% of rainbow troutin scale samples from the Nakusp wharf (Winsby and Stone 1996), and in 1995, 6

5 Bull trout stocking was temporarily discontinued after 1998 due to concerns about declining kokaneenumbers.



of 16 fish (37%)6 in the Nakusp scale collection were clipped (Thorp 1995). In the1998-99 surveys, 5 of the 12 clipped rainbow trout7 (42%) were likely Gerrards.Therefore it seems likely that the Gerrard stocking program has provided asubstantial proportion of the larger rainbow trout in the fishery. However, largerrainbow trout (> 50 cm) comprise only 5-10% of the total rainbow trout harvest(Figure 6), indicating a low survival rate and limited contribution to the fisheryoverall8. Natural reproduction of this stock is likely very low. Clips in the 1998-99surveys represented four different releases between 1990 –1994 (Table 7). Duringthis time period, a total of 283,417 yearling and 5,170 age 2 Gerrards were releasedin the reservoir (Appendix 2).

The Gerrard stocking program was initiated as a temporarily substitute for thelarge-size yellowfin rainbow strain which are believed to have resided in the lakesbefore dam construction (Sebastian et al. 2000). Development of a yellowfinrainbow trout stocking program based on collection of wild broodstock fromArrow tributaries has been impossible due to difficulties in capturing fish duringthe spring spawning run, and hybridization with Gerrards (Coast RiverEnvironmental Services 1995; R.L. & L. 1993; Toth and Tsumura 1996).

Since it was impossible to obtain broodstock from Arrow tributaries, Winsby andStone (1996) recommended a genetic screening of Kinbasket reservoir tributariesto see whether it would be possible to obtain yellowfin broodstock from sourceswhich are now isolated from Arrow Lakes Reservoir. This work has recently beencompleted. Genetic assessments suggest that it would not be advisable to use fishfrom Kinbasket tributaries, if the primary goal is to maintain current geneticdiversity of Arrow reservoir rainbow (Taylor and McLean 1999; Taylor 2000).Stocking of fertile Gerrards appears to have allowed interbreeding with theremaining yellowfin spawners in both the Arrow and Kinbasket reservoirs (Taylorand McLean 1999). However, if restoration of a yellowfin phenotype is a priority, itmight be possible to use fish from Kinbasket tributaries (Taylor and McLean 1999).It is likely, though, that broodstock collection from Kinbasket tributaries would bedifficult, as was the case in Arrow tributaries, and the fish may not be of the largepiscivorous type.

4.2.2.1 Recommendations

The CBFWCP Fisheries Technical Committee should reconsider the efficacy ofstocking programs for smaller Hill Creek rainbow and Gerrards. Currently thesmaller rainbows make up less than 3% of the catch, and fertilization is likely to

6 These 6 fish comprised only 0.72% of 694 rainbow trout examined in the creel for that year.7 Assuming fish >50 cm were Gerrard stock8 If 5 of 362 measured rainbow trout in 1998-99 were stocked Gerrards, the contribution of stocked fish tothe fishery would ~25 Gerrards per year (5/362 X 1,800).



increase growth and survival of natural recruits. If a large-size rainbow fishery isconsidered to be a priority for the Arrow reservoir, it will be necessary to stockGerrards. Use of sterile Gerrards would avoid further genetic interactions withany remaining yellowfins. Alternately, there is the possibility of managing forendemic rainbow trout and bull trout without a fishery for larger trout.

5.0 References

Agresti A. and Coull, B. 1998. Approximate is better than exact for interval estimation ofbinomial proportions. American Statistician 52: 119-126.

ARA Consulting Group. 1994. The Kinbasket Sport Fishery Creel Survey Design. Reportprepared for Columbia Basin Fish and Wildlife Compensation Program by ARAConsulting Group, Inc., Vancouver, B.C.

Arndt, S. 2001. Summary of Winter Creel Surveys for Columbia and Windermere Lakesfrom 1995-2001. Technical report of the Columbia Basin Fish & WildlifeCompensation Program. 18 pp. + appendices.

Coast River Environmental Services. 1995. Tonkawatla Creek Rainbow Trout Evaluationand Broodstock Collection. Report prepared for the Columbia Basin Fish andWildlife Compensation Program by Coast River Environmental Services Ltd.,Vancouver, B.C.

Doxey, M. 2000. Fishery Management Report for Sport Fisheries in the Lower TananaRiver Management Area for 1998. Alaska Dept. of Fish & Game, Fishery MgmtRep. No. 00-10.

Kapuscinski, A.R. and L.D. Jacobson. 1987. Genetic Guidelines for Fisheries Management.Dept. of Fisheries and Wildlife, University of Minnesota. 66 pp.

Latham, S.J and E.B. Tayor. 2001. Hatchery-mediated reduction of genetic differentiationamong bull trout populations: assessment of mechanisms and consequences usingneutral genetic markers. Pages 89-97 in Brewin, M.K., A.J. Paul, and M. Monita,editors. Bull Trout II conference proceedings, Trout Unlimited Canada, Calgary,Alberta.

Pieters, R. and 12 other authors. 1998. Arrow Reservoir Limnology and Trophic Status –Year 1 (1997/1998) Report. Fisheries Project Report No. RD 67 1998, Ministry ofEnvironment, Lands, and Parks, British Columbia.

Pollock, K.H., C.M. Jones, and T.L. Brown. 1994. Angler Survey Methods and TheirApplications in Fisheries Management. American Fisheries Society SpecialPublication 25.



Quinn, S. 2000. The status of recreational fisheries for burbot in the United States. Pages128 –135. In V.L. Paragamian and D.W. Willis, editors. Burbot: biology, ecology,and management. American Fisheries Society, Fisheries Management Section,Publication Number 1, Bethesda.

R.L. & L. Environmental Services. 1993. Native Arrow Lakes Rainbow Trout Brood StockCollection, 1992 Collection Data. Report prepared for Mica Fish and WildlifeCompensation Program. 8 p. + Appendix.

Sebastian, D., H. Andrusak, G. Scholten, and L. Brescia. 2000. Arrow Reservoir FishSummary. Stock management report prepared for BC Ministry of Fisheries andColumbia Basin Fish & Wildlife Compensation Program.

Taube, T.T. 2000. Area Management Report for the Recreational Fisheries of the UpperCopper/Upper Susitna River Management Area, 1996-1997. Alaska Dept. Fish &Game, Fishery Mgmt. Rep. No. 00-4.

Taylor, E.B. 2000. Microsatellite DNA polymorphism in rainbow trout (Oncorhynchusmykiss) from the Upper Arrow and Kinbasket watersheds in British Columbia,Part II: analysis at additional loci. Technical report prepared for the ColumbiaBasin Fish & Wildlife Compensation Program.

Taylor, E.B. and J.E. McLean. 1999. Microsatellite DNA polymorphism in rainbow trout(Oncorhynchus mykiss) from the Upper Arrow and Kinbasket Watersheds in BritishColumbia: can “Yellowfin” rainbow trout be identified genetically? Technicalreport prepared by Department of Zoology, University of BC for CBFWCP,December 1999.

Thorp, G. 1995. Hill Creek Hatchery and Spawning Channel 1995 Annual Report. BCEnvironment, Fisheries Program, Kootenay Region. 38 pp. + Appendices.

Toth, B.M. and K. Tsumura. 1996. Arrow Lakes Rainbow Trout Broodstock Collection.Ministry of Environment, Lands, and Parks, Fisheries Branch. Fisheries ProjectReport No. RD60.

Winsby, M. and E. Stone. 1996. Hill Creek Hatchery Assessment and Operating PlanOptions Report. Report prepared for Columbia Basin Fish & WildlifeCompensation Program by Hatfield Consultants, West Vancouver, BC.



Appendix 1. Hill Creek Hatchery contribution to the harvest and total populationsof bull trout and rainbow trout in the Arrow Lakes reservoir in 1998 and 1999 andapproximate costs per fish.

Bull TroutTotal Contributionto Harvest

Cost1 perHarvested Fish

Total Contribution toLake Population2

Cost1 per Fishin Population

1998 15 $8,556 83 $1,5461999 20 $6,417 187 $686

Rainbow Trout1998 53 $1,211 483 $1331999 28 $2,292 276 $232

1 The 1995-96 cost estimate for Hill Creek Spawning Channel and Hatchery was $383,500including $23,000 for the creel survey, and $5,000 for helicopter surveys of kokanee spawners(1995-96 task sheet). Average cost for the 5 previous years was $385,000 including the hatcherymanager’s salary (~$40,000) that was paid by Ministry of Environment at that time. There were nomajor capital projects noted during these years.

Cost estimates of the spawning channel were not separated from the hatchery costs until 2001-02(then estimated at $163,000). Subtraction of the creel and helicopter surveys and the spawningchannel leaves $192,500 as a conservative estimate of the cost of the bull trout and rainbow troutstocking programs in 1995-96. This year was used to estimate the cost per fish in the table above.Due to the requirement for wild broodstock collection and a longer hatchery rearing period, 2/3 ofthe $192,500 was apportioned to the bull trout program ($128,333) and the remainder ($64,166) tothe rainbow trout programs.

2 Fish surviving to catchable size



Appendix 2. Stocking records for Arrow Lakes reservoir from 1990 – 1997.

Number of fish released by ageSpecies/Stock Year Yearling (age 1+) Age 2

Rainbow/Gerrard1 1990 29,575 -

1991 38,272 -1992 81,716 -1993 73,252 -1994 60,602 5,1701995 75,460 5,0691996 51,842 -1997 82,348 -

Rainbow/Littoral(Hill Creek)2 1990 3,120 -

1991 6,409 -1992 3,066 -1993 ? -1994 ? -1995 10,308 -1996 7,235 -1997 6,634 -

Bull Trout3 1990 55,671 -1991 171,386 -1992 65,046 -1993 103,506 6,5661994 27,311 5,0631995 - 2,4671996 - 13,3081997 - 392

1 data from Appendix 3b of Sebastian et al. 20002 data from Appendix 3a of Sebastian et al. 20003 data from BullTroutreleases.xls provided by Hill Creek hatchery



Appendix 3. Length and weight distributions of clipped rainbow trout in the 1998and 1999 Arrow Lakes reservoir creel survey (both years combined).

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