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CONSERVATIONCONSERVATION

REPORT REPORT

SERIESSERIES

Summer Sport Fishery for Lake Trout, Walleye and Northern Pike at Cold Lake, Alberta, 2005

CONSERVATIONCONSERVATION

REPORT REPORT

SERIESSERIES 25% Post Consumer Fibre

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The Alberta Conservation Association is a Delegated Administrative Organization under Alberta’s Wildlife Act.

Summer Sport Fishery for Lake Trout, Walleye and

Northern Pike at Cold Lake, Alberta, 2005

Bill Patterson

Alberta Conservation Association #111, 4999‐98 Avenue, Twin Atria Building

Edmonton, Alberta, Canada T5R 2X3.

i

Report Series Editor PETER AKU Alberta Conservation Association #101, 9 Chippewa Rd Sherwood Park AB T8A 6J7 Conservation Report Series Type Data, Technical ISBN printed: 978‐0‐7785‐6501‐7 ISBN online: 978‐0‐7785‐6502‐4 Publication No.: T/144 Disclaimer: This document is an independent report prepared by the Alberta Conservation Association. The authors are solely responsible for the interpretations of data and statements made within this report. Reproduction and Availability: This report and its contents may be reproduced in whole, or in part, provided that this title page is included with such reproduction and/or appropriate acknowledgements are provided to the authors and sponsors of this project.

Suggested citation: Patterson, B. 2006. Summer sport fishery for lake trout, walleye and northern pike at

Cold Lake, Alberta, 2005. Data Report, D‐2006‐005, produced by Alberta Conservation Association, Edmonton, Alberta, Canada. 24 pp. + app.

Cover photo credit: David Fairless Digital copies of conservation reports can be obtained from: Alberta Conservation Association #101, 9 Chippewa Rd Sherwood Park AB T8A 6J7 Toll Free: 1‐877‐969‐9091 Tel: (780) 410‐1999 Fax: (780) 464‐0990 Email: info@ab‐conservation.com Website: www.ab‐conservation.com

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EXECUTIVE SUMMARY

The Alberta Conservation Association (ACA) conducted a creel survey at Cold Lake

during the 2005 summer fishing season to provide information on angler use, sport fish

yield and population structure. The survey focused primarily on the lake trout sport

fishery although data on the walleye and pike sport fisheries were also collected.

Access point surveys were conducted from two sites, the Cold Lake Marina (hereafter

CLM) and the Cold Lake Provincial Park (hereafter PP) from 21 May to 21 August 2005.

During the survey period, approximately 69% of the angling effort was from CLM and

PP combined. The remaining 31% was by anglers who used access points not surveyed

(e.g., provincial parks, boat launches). An estimated 9,088 anglers (95% CI = 7,839 ‐

10,393, n = 1,940) fished the lake for 31,525 h (95% CI = 27,112 – 36,236, n = 6,933) or 0.90

h/ha (95% CI = 0.78 – 1.04).

At the survey sites recreational anglers were the majority (i.e., CLM = 83%, n = 1,060;

PP = 99%, n = 880). Anglers utilizing the guiding services available on Cold Lake

represented 17% and 1% of the CLM and PP anglers, respectively.

An estimated 1,098 lake trout (95% CI = 853 – 1,371, n = 244) were harvested by anglers

during the survey period of which 68% were harvested by recreational anglers while

guided anglers harvested 32%. Simulations using three scenarios of incidental

mortality (i.e., low 5%, moderate 10%, and high 15%) suggest additional 174 ‐ 521 fish,

respectively could potentially die from incidental mortality.

An estimated 3,473 lake trout (95% CI = 2,829 – 4,174, n = 858) were reported released by

anglers, of which 75% were by recreational anglers and 25% by guided anglers.

Generally, the length of the harvested lake trout ranged 352 – 803 mm (fork length) and

weight ranged 2,350 – 7,500 kg. Mean weight of a trout harvested by either group was

4,443 g (95% CI = 4,427 – 4,642, n = 161) with estimated yield of 0.140 kg/ha

(95% CI = 0.139 – 0.144). The total catch rate for lake trout was 0.162 fish/h. Guided

anglers had a higher total catch rate (harvest + released fish) than the recreational

anglers i.e., 0.427 fish/h versus 0.130 fish/h. Harvest and release rates were 0.036 fish/h

and 0.126 fish/h, respectively. Of the 165 observed harvest, 8 were protected‐length

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fish. Reported release rates for protected‐length and legal‐length lake trout were

0.089 fish/h and 0.037 fish/h, respectively. All lake trout captured were mature.

An estimated 30 walleye (95% CI = 84 – 526, n = 26) were harvested by anglers during

the survey period. All walleye were harvested by recreational anglers; guided anglers

did not capture any walleye. Estimated mean weight of harvested walleye was

2,328 g/fish (95% CI = 2,175 – 2,519, n = 18) and yield was 0.015 kg/ha (95% CI = 0.006 ‐

0.035). Anglers released 745 walleye (95% CI = 347 – 1,532, n = 101). The incidental

mortality of walleye was an additional 41 fish (95% CI = 18 ‐ 73). Overall, the catch rate

for walleye was very low. The exaggeration of catch rates may indicate that fishing

success is much poorer than reported.

An estimated 554 pike (95% CI = 409 – 697, n = 124) were harvested by anglers during

the survey period. Similar to walleye, all pike were harvested by recreational anglers;

guided anglers did not capture any. Estimated mean weight of harvested pike was

2,224 g/fish (95% CI = 1,997 – 2,425, n = 55) and yield was 0.036 kg/ha (95% CI = 0.030 ‐

0.038). Anglers released 7,855 pike (95% CI = 6,458 – 9,369, n = 1,530). Based on data

collected from the test angling, pike released had a mean weight of 0.909 kg/fish (95%

CI = 0.861 – 0.946, n = 110); estimated additional yield due to incidental mortality was

0.011 kg/ha (95% CI = 0.009 ‐ 0.013). Age‐class distribution for pike (both recreational

harvest and test angling) was moderately broad with low densities. The catch rate was

low for legal‐size pike and moderate for protected‐length fish. Pike were growing to

the legal‐size limit in five years. No large fish (>70 cm TL) were caught. Sport anglers

had very poor success and a small portion of anglers harvested the majority of fish.

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ACKNOWLEDGEMENTS

The Alberta Conservation Association funded this work. I thank Troy Furukawa and

Kevin Yachyshyn for conducting the field component of this work; spending countless

hours interviewing anglers on land and water, test angling, and conducting ratio‐of‐use

(ROU) surveys. I also thank Alberta Sustainable Resource Development (ASRD),

particularly George Walker and Wes English, for arranging accommodations and a

work boat for the field, conducting ROUs, and providing local knowledge and fisheries

expertise. I am grateful to the anglers who contributed their time and fish to this study,

Alberta Student Temporary Employment Program (STEP) for financial support, and

The Fish’n Hole for discounts on equipment.

CONSERVATIONCONSERVATIONREPORT REPORT SERIESSERIES

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TABLE OF CONTENTS

EXECUTIVE SUMMARY.............................................................................................. ii

ACKNOWLEDGEMENTS...........................................................................................iv

TABLE OF CONTENTS ................................................................................................v

LIST OF FIGURES.........................................................................................................vi

LIST OF TABLES..........................................................................................................vii

LIST OF APPENDICES ............................................................................................. viii

1.0 INTRODUCTION................................................................................................. 1 1.1 General introduction ......................................................................................... 1 1.2 Study rationale ................................................................................................... 2

2.0 STUDY AREA..................................................................................................... 2

3.0 MATERIALS AND METHODS ....................................................................... 4 3.1 Survey design ..................................................................................................... 4 3.2 Access point creel survey.................................................................................. 4 3.3 Ratio‐of‐use surveys .......................................................................................... 5 3.4 Test angling......................................................................................................... 5 3.5 Biological fish data............................................................................................. 6 3.6 Data management and analysis ....................................................................... 7

4.0 RESULTS ............................................................................................................. 9

4.1 Survey effort ....................................................................................................... 9 4.2 Angler surveys ................................................................................................. 10 4.3 Lake trout harvest and yield .......................................................................... 11 4.4 Lake trout population structure..................................................................... 12 4.5 Walleye harvest and yield .............................................................................. 15 4.6 Walleye catch .................................................................................................... 16 4.7 Northern pike harvest and yield.................................................................... 17 4.8 Northern pike population structure.............................................................. 17 4.9 Summary ........................................................................................................... 20

5.0 LITERATURE CITED ...................................................................................... 22

6.0 APPENDICES ................................................................................................... 25

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LIST OF FIGURES

Figure 1. A map of Cold Lake, Alberta. . ..............................................................................3

Figure 2. A flow chart outlining the process used for estimating parameters for the access point creel surveys on Cold Lake, 2005. ...................................................8

Figure 3. Length‐frequency distribution of lake trout harvested by anglers from Cold Lake during the 2005 summer survey. ...............................................................12

Figure 4. Length‐at‐age of lake trout sampled from the angler harvest and by test anglers from Cold Lake 2005. ..............................................................................13

Figure 5. Age‐class distribution of lake trout as sampled from the sport fishery .......14

Figure 6. Distribution of fork lengths of mature female and male lake trout harvested by anglers from Cold Lake during the 2005 summer survey.. .......................14

Figure 7. Distribution of total catch rates for walleye collected during summer creel surveys from the 1990s and 2000s.. .....................................................................16

Figure 8. Age‐class distribution of pike harvested by the sport fishery and test angling during the Cold Lake creel survey in 2005..........................................18

Figure 9. Length‐class distribution of pike harvested during the Cold Lake creel survey in 2005 . ......................................................................................................19

Figure 10. Length‐at‐age of northern pike harvested by anglers during the 2005 survey ..................................................................................................................................19

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LIST OF TABLES

Table 1. Summary of the ratio‐of‐use surveys conducted at Cold Lake, 2005. ...........10

Table 2. Summary of observed and estimated number of anglers and angler‐hours on Cold Lake from 21 May to 21 August 2005 ..................................................10

Table 3. Summary of catch rates during the Cold Lake creel survey in 2005..............11

viii

LIST OF APPENDICES

Appendix 1. An example of a creel survey field form..................................................25

Appendix 2. Daily summary data from the creel surveys at Cold Lake Marina (CLM) and the Cold Lake Provincial Park (PP) in 2005. .....................26

Appendix 3. Data collected during 22 Ratio‐of‐use (ROU) surveys conducted during the summer creel survey at Cold Lake 2005. .............................28

Appendix 4. Standardized probability density function of the estimated number of anglers at Cold Lake during the 2005 survey..........................................29

Appendix 5. Standardized probability density function of the number of angling hours estimated at Cold Lake during the 2005 survey. .........................29

Appendix 6. Standardized probability density function of the angling pressure (h/ha) estimated at Cold Lake during the 2005 survey..........................30

Appendix 7. Standardized probability density function of the number of lake trout harvested from Cold Lake during the 2005 survey................................30

Appendix 8. Standardized probability density function of the yield of lake trout from Cold Lake during the 2005 survey. .................................................31

Appendix 9. Standardized probability density function of the number of lake trout associated with incidental mortality simulations and the total harvest of lake trout from Cold Lake during the 2005 survey............................31

Appendix 10. Standardized probability density function of the mean weight of lake trout harvested during the 2005 survey .................................................32

Appendix 11. Biological data collected from sport angler‐harvested fish at Cold Lake in the summer of 2005.......................................................................33

Appendix 12. Biological data collected from fish sampled during test angling at Cold Lake, 2005. ..........................................................................................41

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1.0 INTRODUCTION 1.1 General introduction

Lake trout (Salvelinus namaycush) are native to North America, are long‐lived, grow to

large sizes, and are adapted to deep, cold oligotrophic lakes (Shuter et al. 1998). These

attributes make them a prized sportfish throughout their range (Nelson and Paetz 1992;

Scott and Crossman 1998). However, lake trout are also characterized by having slow

growth rates, late maturity and relatively low reproductive rates making them

vulnerable to overexploitation from angling (Shuter et al. 1998; Post et al. 2002),

especially in areas close to large urban centers (Pacas and Hunt 2004).

Lake trout occur in Alberta and are believed to be native to the Slave, Peace, and Beaver

River drainages and in headwater lakes of the Athabasca, North and South

Saskatchewan river drainages (Nelson and Paetz 1992). To protect these fish from

overexploitation, Alberta Fish and Wildlife implemented fishing regulations that allow

for the possession of one lake trout > 65 cm total length (TL) (Alberta Guide to

Sportfishing Regulations 2005). Alberta currently does not have a management

strategy for lake trout, therefore, parameters commonly used to assess sport fisheries

are discussed (e.g., size distribution, growth, and maturity).

Prior to the mid 1990s, high angling pressure, combined with high fish harvest rates,

resulted in the over‐harvest of walleye (Sander vitreus) and northern pike (Esox lucius)

populations of several lakes in Alberta (Sullivan 2003a). To aid the recovery of these

fisheries, the Alberta Sustainable Resource Development (ASRD) implemented two

new management strategies, the Alberta’s Walleye Management Recovery Plan

(WMRP) in 1996 and Alberta’s Northern Pike Management and Recovery Plan

(NPMRP) in 1999 (see Berry 1995, 1999). Through strategies identified in these two

recovery plans, each fishery was assigned one of three management status as 1)

collapsed, 2) vulnerable, or 3) stable. Sport fishing regulation on individual lakes were

then modified according to the status assigned (Sullivan 1998). Accordingly, the

walleye fishery on Cold Lake was classified as a vulnerable fishery in 1996 and anglers

were restricted to harvesting up to three walleye (i.e., daily maximum bag limit), each

with a minimum size limit of 50 cm TL. Similarly, the northern pike fishery was

2

designated as a stable‐recreational fisheries in 1999 and anglers were restricted to a

daily harvest of three northern pike, each with a minimum size limit of 63 cm TL.

1.2 Study rationale

The Alberta Conservation Association (ACA) and ASRD conducted a joint creel survey

at Cold Lake during the 2005 summer fishing season to provide information on angler

use and sport fish yield. Creel surveys are a non‐invasive technique that can effectively

estimate the parameters required (e.g., angler use, sport fish yield and sport fishery

structure) for management. The primary purpose of the survey was to examine the

lake trout fishery at Cold Lake and to also collect data on the walleye and pike fisheries

to provide ASRD with current data describing these fisheries for the summer of 2005.

With Alberta’s increasing population and increasing accessibility to sport fisheries,

discussions between ACA and ASRD suggested it was timely and important to survey

the walleye and pike fisheries at Cold Lake.

2.0 STUDY AREA

Cold Lake (TWP 63 ‐ 65, RNG 26, 27, W3) located approximately 300 km northeast of

the City of Edmonton, is a mesotrophic lake in the Beaver River Drainage basin (Figure

1). It has a surface area of 34,907 ha and a maximum depth of 99 m (ASRD unpublished

data). Several rivers and streams flow into the lake, including the Medley and the

Martineau rivers. The outlet, the Cold River, flows eastward to the Beaver River (in

Saskatchewan). A more complete description of the physical, chemical and biological

characteristics may be found in Mitchell and Prepas (1990). The Town of Cold Lake is

located on the southwest corner of the lake. Cold Lake is shared by the Provinces of

Alberta and Saskatchewan. The Saskatchewan side of the lake is located within

Meadow Lake Provincial Park. Alberta Community Development maintains three

camping and day‐use facilities on the lake: Cold Lake Provincial Park, Frenchman’s Bay

Provincial Recreation Area and English Bay Provincial Recreation Area. Four other

areas provide public access to the lake and are operated by local municipalities and the

Saskatchewan Provincial Government.

3

Calgary

Cold Lake

Edmonton

Cold Lake

ColdRiver

Martineau River

MedleyRiver

Cold Lake Marina

Hwy 55

Hw

y 28

ALB

ERT A

SASK

ATC

HEW

AN

N

Calgary

Cold Lake

Edmonton

Cold Lake

Calgary

Cold Lake

Edmonton

Cold Lake

ColdRiver

Martineau River

MedleyRiver

Cold Lake Marina

Hwy 55

Hw

y 28

ALB

ERT A

SASK

ATC

HEW

AN

N

Figure 1. A map of Cold Lake, Alberta (scanned from Mitchell and Prepas 1990). The

Cold Lake Marina and the Cold Lake Provincial Park angler survey sites are labeled on the map. The stippled grey area indicates a portion of Cold Lake’s drainage basin and the small black unlabelled arrows indicate the flow of creeks and rivers.

4

3.0 MATERIALS AND METHODS

3.1 Survey design

From 21 May to 21 August 2005, a creel survey was conducted on Cold Lake. This

survey was comprised of two components, an access point survey (Pollock et al. 1994)

and a ratio‐of‐use (ROU) survey. The ratio‐of‐use surveys provided a multiplier that

was used to extrapolate estimates of parameters (e.g., angler effort, harvest) to spatial

strata that was not surveyed (i.e., access sites that were not surveyed).

3.2 Access point creel survey

3.2.1 Angler interviews

Upon returning to the survey access point, all angling parties were asked a series of

questions regarding the number of hours fished, number of each species kept and

released, the number of anglers, angling method, targeted species, use of electronics,

use of barbless hooks, and residence. Two creel clerks conducted the angler surveys.

These data were recorded on a creel survey data form (Appendix 1). Creel clerks made

a subjective evaluation of each angler’s skill level. Children and anglers that lacked

equipment and knowledge regarding fishing were classified as novices. Anglers that

demonstrated clear superiority in equipment and knowledge were classified as

professionals. All other anglers were considered to have moderate skill. Anglers that

were guided by a guiding service were classified as guided anglers. Data collected

from guided anglers was analyzed separately because it was assumed guided anglers

were more successful than recreational anglers and their data would bias the results of

the sport angler survey.

3.2.2 Spatial extent of survey

The access point surveys were conducted at both the marina located within the Town of

Cold Lake (CLM) and at the Cold Lake Provincial Park (PP) (Figure 1). These areas are

located at the southwest corner of Cold Lake.

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3.2.3 Temporal extent of sampling

The access point surveys were stratified into weekdays (Monday‐Thursday) and

weekend days (Friday‐Sunday and statutory holidays). Surveyed days were further

stratified into morning (0830 ‐ 1530) and afternoon (1530 ‐ 2300) shifts. Each shift

consisted of a 14‐day rotation. Each survey location was creeled for five consecutive

days (i.e., PP surveyed Friday to Tuesday and CLM surveyed Wednesday to Sunday).

The remaining four days were days‐of‐rest. This schedule was repeated seven times

throughout the summer. Survey dates and summary information are listed in

Appendix 2.

3.3 Ratio‐of‐use surveys

Ratio‐of‐use surveys provide a site‐use ratio (e.g., 493 anglers out of 664 interviewed

used the access sites as their landing site; Appendix 3) that is used to extrapolate creel

survey parameters (e.g., number of anglers, number of hours, number of fish caught) to

spatial strata that are not surveyed. Lake activity surveys include interviewing anglers

on the lake as they were randomly encountered by boat. The lake activity interview

was identical to the access site interview but included the location of angler party

landing (i.e., where the boat touched shore at the end of the angling trip). The surveys

had a temporal stratification of weekdays and weekend days and two shifts (i.e.,

0800 ‐ 1530 and 1530 ‐ 2300) that reflected angler use. Twenty‐two lake activity surveys

were conducted during the survey period. For safety, lake activity surveys were

completed by two crewmembers.

3.4 Test angling

Catching lake trout require specialized equipment and expertise. Because of the

knowledge and specialized equipment required to successfully angle lake trout, the

creel clerks were not required to test angle for lake trout. Instead, Cold Lake Area

ASRD staff asked the local guiding professionals to measure and record the lengths of

the lake trout they caught.

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Since sport anglers were required to release walleye and pike that were shorter than the

minimum size limit (walleye 50 cm, pike 63 cm TL), creel clerks could not obtain any

information regarding these protected‐length fish. Hence, test angling was conducted

throughout the survey period to collect additional information on the age and size

frequency distributions of walleye and pike populations. Test angling consisted of creel

clerks, as well as ACA and ASRD fisheries staff, all of varying skill levels, fishing for

walleye and pike using lures, baits, and adopting techniques that would normally be

used in the sport fishery. Test anglers recorded the number of hours fished, and the

fork length (FL, ±1mm), of all fish caught. Ageing structures collected included the first

three rays of the left pelvic fin for walleye and pike. All fish caught during the test

angling were released. To reduce handling time, weights from test angling‐sampled

fish were not collected. Therefore, weight was estimated using a length‐weight

regression (WT = (1E‐05)(FL)(2.9941), r2 = 0.91, df = 897, P < 0.001) after applying an FL to

TL conversion. The ratio of legal‐length fish to protected‐length fish sampled during

the test angling was assumed to be equal to the corresponding ratio from the sport

fishery following Sullivan (2003b). These ratios were compared to determine the angler

exaggeration rate, and to estimate the total catch rates for walleye and pike. Calculated

weights of fish caught during the test angling were applied to incidental mortality and

total yield calculations. The catch rate calculated from the test angling was not

included in any of the calculations regarding sport angler catch rate, effort (h) or fishing

pressure (h/ha).

3.5 Biological fish data

Creel clerks, when permitted, collected biological data from fish that were harvested by

anglers. Data collected included FL (±1 mm), total weight (±10 g), ageing structures,

sex, and state of maturity. Ageing structures included otoliths for lake trout, the left

operculum and the first three rays of the left pelvic fin for walleye, the left cleithrum

and the first three rays of the left pelvic fin for pike. Sample material and ages were

determined according to Mackay et al. (1990). Sex and state of maturity of each fish

was determined following Duffy et al. (2000).

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3.6 Data management and analysis

Field data were recorded on field data forms in pencil by creel clerks and then

transcribed into Microsoft Excel files by a professional data entry service using double

entry verification. Prior to analysis, frequency distributions of each creel survey

parameter were calculated and the original data sheets and creel daily journals used to

investigate and verify outliers. Scatter plots of weight‐length and length‐age were

generated to identify outliers. Outliers were identified visually and omitted if

measurement or recording error was suspected.

I used a bootstrap technique to calculate estimates and confidence intervals for number

of anglers, number of hours, angling pressure (h/ha), harvest and yield (i.e., kg/ha) of

sport fish. Sullivan (2004) summarized bootstrapping as a statistical procedure

whereby an original sample of the population is subsequently re‐sampled and a new

mean calculated. Bootstrap samples are assumed to approximate the distribution of

values that would have arisen from repeatedly sampling the original population

(Haddon 2001). Sullivan (2004) explains that repeating this procedure thousands of

times results in a distribution of possible means describing the likelihood of the true

(population) mean being within that distribution. This group of means represents the

distribution of possible means from data with the same scale of variation as observed in

the original data set. Frequentist parameter estimates (e.g., means) are typically equal

to maximum‐likelihood estimates (MLE) for the parameters of the specified probability

density function (Gotelli 2004). Empirical confidence intervals (95% CI) were calculated

following Haddon (2001). The final proportions (i.e., probability densities) were

standardized to range between 0 and 1 (Paul et al 2003).

The site‐use ratio (e.g., 493 anglers out of 664 interviewed used the access sites)

collected from the lake activity surveys, as a binomial probability, has a range of

variation. I simulated this binomial (using Microsoft Excel’s Random Number

Generation), thereby creating a list of possible site‐use ratios, with a range of variation

that is correlated to the size of the original data sample.

Each parameter that was obtained from creel survey data (e.g., number of anglers,

number of hours, number of fish caught, yield was estimated to include spatial and

8

temporal strata that were not surveyed. Each parameter and estimate is presented as a

likelihood profile, using the simulation procedure described above and combined by

multiplying or adding the likelihood profiles. A flow chart describing the steps for

calculating estimates for each creel site and for the survey is presented in Figure 2.

Site Estimates

Weekend meane.g., # hours +

Site 1

x# Weekend days not surveyed

Sum of weekend dayshours observed

+

Site 1 estimatee.g., # hours

Estimate of weekendday hours=

Weekday meane.g., # hours +x

# Weekdays not

surveyed

Sum of weekday hours

observed

Estimate of weekdayhours=


Above steps repeated for Site 2

= x

+

Sites estimate e.g., # hours

Survey Estimate

Ratio‐of‐useSurvey estimate e.g., # hours

Site Estimates

Weekend meane.g., # hours +

Site 1

x# Weekend days not surveyed

Sum of weekend dayshours observed

+


Estimate of weekendday hours=

Weekday meane.g., # hours +x

# Weekdays not

surveyed

Sum of weekday hours

observed

Estimate of weekdayhours=




= x

+

Sites estimate e.g., # hours

Survey Estimate

Ratio‐of‐useSurvey estimate e.g., # hours

Figure 2. A flow chart outlining the process used for estimating parameters for the access point creel surveys on Cold Lake, 2005. Circles represent values with no variance (i.e., known values or observed data) and rectangles represent data with variation (i.e., likelihood profiles).

Incidental mortality likely contributes to the overall yield of sport fish. For lake trout,

published estimates for incidental mortality ranged from near zero to approximately

15% for typical sportfishing methods (Loftus et al. 1988; Muoneke and Childress 1994;

Persons and Hirsch 1994; Lee and Bergersen 1996). Using this range (0 ‐ 15%) as a

guide, I simulated three levels of incidental mortality: low (5%), medium (10%) and

high (15%). For walleye, a mean incidental mortality was calculated from incidental

mortalities collected from nine previous creel surveys following a multivariate analysis

9

as suggested by Reeves (2004). Reeves (2004) used a multiple regression approach to

calculate incidental mortality from month of capture, incidental location (e.g., stomach,

gill, inner mouth), capture depth, water temperature, length category of walleye

caught, angling gear (e.g., bobber, crank bait), and hook type (e.g., jig, treble). It

seemed reasonable to assume that pike and walleye had similar incidental mortalities

since pike typically had mortalities under 15% (Muoneke and Childress 1994). The total

harvest estimate was determined by adding the resulting incidental mortality estimate

(i.e., fish released x incidental mortality) to the angler harvest estimate.

To quantify catch inequality among anglers for pike, Gini coefficients and angler

success rates were calculated following Baccante (1995). A Gini coefficient of zero

indicates all anglers caught equal numbers of fish and a coefficient of one indicates that

a single angler caught the entire catch.

To quantify size‐class for pike, proportional stock density (PSD) and relative stock

density (RSD) classifications were calculated following procedures in Gablehouse

(1984). The PSD is the number of pike caught that are ≥ 530 mm TL, expressed as a

proportion of the number of fish ≥ 350 mm TL. A high PSD value indicates a larger

portion of mature fish, and therefore can be interpreted as reflecting a more stable

population. The RSD (stock‐quality) is the proportion of pike caught between 350 and

529 mm TL relative to the total number of pike ≥ 350 mm TL. Sport anglers were

required to release pike less than 63 cm TL (protected‐length fish), therefore pike

caught and sampled during test angling were used for RSD calculations.

All data were stored in the Fisheries Management Information System of ASRD.

4.0 RESULTS 4.1 Survey effort

During the surveyed period, 27 weekend days and 21 weekdays were surveyed. At the

CLM, 14 weekend days and 12 weekdays were surveyed. At the PP, 13 weekend days

10

and 9 weekdays were surveyed. Twenty‐two ROU surveys were conducted

throughout the survey period. Table 1 summarizes the number of surveys per stratum.

Table 1. Summary of the ratio‐of‐use surveys conducted at Cold Lake, 2005.

Day strata Shift strata Number of ratio‐of‐use (ROU) surveys

Weekday 0800 to 1530 4 1530 to 2300 5

Weekend day 0800 to 1530 8 1530 to 2300 5

4.2 Angler surveys

During the survey period (21 May to 21 August 2005), 1,940 anglers were interviewed

at both survey sites (Table 2). Specifically, 1,060 anglers at the CLM and 880 anglers at

the PP. The majority of anglers (69%) accessed Cold Lake using the two survey sites

(Appendix 3). An estimated, 9,088 anglers (95% CI = 7,839 ‐ 10,393; Appendix 4) fished

for 31,529 h (95% CI = 27,112 ‐ 36,236, n = 6,933.5; Appendix 5) equivalent to an angling

pressure of 0.90 h/ha (95% CI = 0.78 ‐ 1.04; Appendix 6). Angler catch rates are listed in

Table 3.

Table 2. Summary of observed and estimated number of anglers and angler‐hours on Cold Lake from 21 May to 21 August 2005.

Access site Number of anglers Angler‐hour

Observed Estimated (95% CI) Observed Estimated (95% CI) Cold Lake Marina

1,060 3,346 (2656 ‐ 4098) 3,928.25 12,485 (10,413 ‐ 14,786)

Cold Lake Provincial Park

880 3,399 (2870 ‐ 3951) 3,005.25 11,32 (8,883 ‐ 14,004)

Total 1,940 9,088 (7,839 ‐ 10,393) 6,933.50 31,529 (27,112 ‐ 36,236)

11

Table 3. Summary of catch rates during the Cold Lake creel survey in 2005.

Catch rates Cold Lake Marina

Cold Lake Provincial Park

Sites combined

Lake trout

Observed kept/ h 0.045 0.022 0.036 Reported released legal‐size/h 0.058 0.006 0.037 Reported released protected‐size/h 0.104 0.068 0.089 Total 0.207 0.095 0.162

Walleye

Observed kept/h 0.003 0.005 0.004 Reported released legal‐size/h 0.002 0.000 0.001 Reported released protected‐size/h 0.007 0.021 0.013 Total 0.012 0.026 0.018

Northern pike

Observed kept/ angler‐h 0.018 0.018 0.017 Reported released legal‐size/h 0.030 0.034 0.031 Reported released protected‐size/h 0.144 0.248 0.189 Total 0.192 0.299 0.238

4.3 Lake trout harvest and yield

Estimated angler harvest of lake trout during the 2005 creel survey was 1,098 fish (95%

CI = 853 ‐ 1,371, n = 244; Appendix 7). Anglers accessing the lake though the CLM

harvested 567 lake trout (95% CI = 450 ‐ 692, n = 178) and those using PP harvested 290

(95% CI = 182 ‐ 400, n = 66). The mean weight of a harvested lake trout was

4.443 kg/fish (95% CI = 4.427 ‐ 4.642 kg, n = 161) which resulted in a yield of 0.140 kg/ha

(95% CI = 0.139 – 0.144; Appendix 8). Of the observed lake trout harvested (n = 165),

73% was by anglers at the CLM (32% guided anglers and 41% recreational anglers) and

27% by recreational anglers from the PP; guided angler using the PP did not catch lake

trout.

Overall, anglers reported releasing 3,473 lake trout (95% CI = 2,829‐ 4,174, n = 858)

during the study period. Anglers using the CLM released 2,034 lake trout (95% CI =

1,582‐ 2,529, n = 637) and those from PP released 928 (95% CI = 630‐ 1,230, n = 22). Of

12

the fish reported released, approximately 25% were released by guided anglers using

the CLM; recreational anglers using the CLM and PP released 50% and 25%,

respectively.

When three scenarios of incidental mortality were simulated i.e., 5%, 10% and 15%

mortalities, the additional harvest attributable to these mortality rates were 174 (95% CI

= 140 ‐ 209), 347 (95% CI = 283 – 417) or 521 (95% CI = 424 – 626) fish, respectively

(Appendix 9). Therefore, estimated total harvest of lake trout, including the incidental

mortality simulations, ranged from 1,271 (95% CI = 1,241 ‐ 1,290) to 1,619 fish (95% CI =

1,524 ‐ 1,707). Since the biological data collected by the volunteer anglers was

inadequate, yield estimates associated with the three incidental mortality simulations

could not be calculated.

4.4 Lake trout population structure

Except for one fish that measured 305 mm FL, length of lake trout harvested by anglers

typically ranged 550 – 803 mm FL with a mean of 671 mm (n = 165) (Figure 3). Seven of

the 165 lake trout sampled from the sport harvest were sublegal‐sized fish.

0

0.001

0.002

0.003

0.004

500

550

600

650

700

750

800

850

Fork length (mm)

Catch ra

te (fish

/h)

Figure 3. Length‐frequency distribution of lake trout harvested by anglers from Cold

Lake during the 2005 summer survey.

13

The lake trout sampled from the sport harvest and test angling reached the minimum

size limit (596 mm FL) by ages 9 to 10 (Figure 4). The age‐class distribution of

angler‐harvested lake trout was broad and ranged from 9 to 26 y (Figure 5). The mean

age of fish harvested by the sport fishery was 15 y (n = 159). The lake trout harvested

by anglers had a mean weight of 4,443 g (range = 2,350 ‐ 7,500 g, n = 160) (Appendix 10).

All the lake trout harvested during our survey were mature (Figure 6). Fifty‐two

percent of the catch were males and 48% were females with mean lengths of 673 mm

(range = 550 ‐ 803, n = 73) and 668 mm FL (range = 352 ‐ 785, n = 80), respectively. The

minimum size limit regulation may have biased the length‐at‐maturity sample since it

requires the release of lake trout shorter than 650 mm TL (596 mm FL).

200

300

400

500

600

700

800

900

5 7 9 11 13 15 17 19 21 23 25 27Age (y)

Fork leng

th (m

m)

Angler harvestTest angling

Figure 4. Length‐at‐age of lake trout sampled from the angler harvest and by test

anglers from Cold Lake 2005.

14

0.000

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30Age (y)

Catch (fish/h)

Figure 5. Age‐class distribution of lake trout as sampled from the sport fishery (n = 159, catch/h = 0.036)

0

5

10

15

500 550 600 650 700 750 800 850

Fork length (mm)

Percen

t catch (%

)

Mature females

Mature males

Figure 6. Distribution of fork lengths of mature female and male lake trout harvested

by anglers from Cold Lake during the 2005 summer survey.

15

The reported catch rate for lake trout was 0.162 fish/h with harvest and release rates of

0.036 and 0.126 fish/h, respectively (Table 3). The reported release rates for

protected‐length and legal‐length lake trout were 0.089 and 0.037 fish/h, respectively.

The guided anglers using the CLM had higher catch rates (harvest = 0.115 fish/h,

protected‐length release = 0.190 fish/h, and legal‐length release = 0.122 fish/h) for lake

trout than the recreational anglers using either the CLM (harvest = 0.031 fish/h,

protected‐length release = 0.086 fish/h and legal‐length release = 0.045 fish/h) or the PP

(harvest = 0.022 fish/h, protected‐ length release = 0.068 fish/h and legal‐length release =

0.006 fish/h). The guided anglers using the PP did not catch any lake trout.

4.5 Walleye harvest and yield

Anglers harvested an estimated 230 walleyes (95% CI = 84 ‐ 526, n = 124) during the

survey. Approximately 35 (95% CI = 17 ‐ 56, n = 10) and 65 walleye (95% CI = 32 ‐ 110,

n = 16) were harvested from the CLM and the PP, respectively. Harvested walleye had

a mean weight of 2.238 kg (95% CI = 2.175 ‐ 2.519, n = 18) resulting in a yield of 0.015

kg/ha (95% CI = 0.006 ‐ 0.035). Biological data collected from harvested walleye are

listed in Appendix 11.

Anglers released an estimated 745 walleyes (95% CI = 347 ‐ 1,532, n = 101). According

to Sullivan (2003), and based on catch rate data collected from 20 Alberta lakes, angler

exaggerations of walleye catch rates are negatively correlated with release rates and

anglers exaggerated their catch rate by 3.7 times (exaggeration factor). Applying this

exaggeration factor to Cold Lake would suggest that fishing success was likely four

times poorer than indicated by anglers.

By applying an incidental mortality of 5.3% (95% CI = 4.2 ‐ 6.6%, n = 9) to the estimate of

released walleye, the additional number of fish dying because of incidental mortality

was 39 (95% CI = 18 ‐ 73); no walleye were sampled during test angling.

16

4.6 Walleye catch

Due to the lack of biological data from the sport fishery and the test angling, the stock

assessment indices described in the WMRP and Sullivan (1998) could not be calculated

for walleye. However, anglers reported catch rates during the creel survey and these

are described below.

The total catch rate of walleye was 0.018 fish/h with a harvest rate of 0.004 fish/h. The

reported release rates for legal‐size and protected‐length fish were 0.001 fish/h and

0.013 fish/h, respectively. Cold Lake, compared to other Alberta lakes, had a very low

catch for walleye (Figure 7). This data may indicate a low density of walleye.

According to the creel clerks who were accomplished anglers, test angling for walleye

was very challenging.

Recreational anglers using the CLM had similar harvest rates as those using the PP

(Table 3). However, recreational anglers using the PP reported higher release rates than

those using the CLM. The guided anglers using either the CLM or the PP did not catch

any walleye.

0.00.51.01.52.02.53.03.54.04.55.0

Pigeon ʹ06

Pigeon ʹ03

Buck ʹ04

Wolf ʹ05

Spencer ʹ92

Pine

hurst ʹ92

Baptiste ʹ99

Pine

hurst ʹ93

Pine

hurst ʹ97

Beav

er ʹ98

Pine

hurst ʹ94

Baptiste ʹ97

Marie ʹ96

Beav

er ʹ05

Baptiste ʹ95

Iron

woo

d ʹ96

Calling ʹ96

Hild

a ʹ97

Touc

hwoo

d ʹ97

Seibert ʹ93

Pigeon ʹ99

Elinor ʹ96

La N

onne ʹ97

Seibert ʹ94

Rock Island ʹ96

Long ʹ96

Seibert ʹ92

Touc

hwoo

d ʹ94

Grego

ire ʹ96

Moo

se ʹ95

Vinc

ent ʹ97

Touc

hwoo

d ʹ93

Ste. Ann

e ʹ95

NSR ʹ97

Touc

hwoo

d ʹ91

Touc

hwoo

d ʹ92

Kehiwin ʹ95

Wolf ʹ99

May ʹ96

Wolf ʹ91

Ethe

l ʹ97

Chris

tina ʹ96

Wolf ʹ92

Wolf ʹ93

Whitefis

h ʹ96

Cold ʹ00

Wolf ʹ94

Cold ʹ05

Floa

tingstone ʹ97

Lac S

te. A

nne ʹ97

Garner ʹ96

Pine ʹ99

Lake and year of creel survey

Walleye

/h

Figure 7. Distribution of total catch rates for walleye collected during summer creel

surveys from the 1990s and 2000s. The catch rate collected during the Cold Lake 2005 creel survey is indicated by the arrow.

17

4.7 Northern pike harvest and yield

Anglers harvested an estimated 554 pikes (95% CI = 409 ‐ 697, n = 124) during the

survey. Approximately 216 (95% CI = 165 ‐ 273, n = 70) and 201 pikes (95% CI = 127 ‐

289, n = 54) were harvested from the CLM and the PP, respectively. Mean weight of

harvested pike was 2.224 kg/fish (95% CI = 1.997 ‐ 2.425 kg, n = 55), resulting in a yield

of 0.036 kg/ha (95% CI = 0.030 ‐ 0.038 kg/ha). Biological data collected from harvested

pike are listed in Appendix 4.

Anglers released 7,855 pike (95% CI = 6,458 ‐ 9,369, n = 1,530). Assuming pike had the

same incidental mortality as walleye (5.3%), the estimated additional number of fish

dying as a result of incidental mortality was 416 (95% CI = 307 ‐ 557) with a yield of

0.011 kg/ha (95% CI = 0.009 ‐ 0.013).

4.8 Northern pike population structure In total, 108 pike were caught and sampled. The total reported catch rate of pike was

0.238 fish/h (harvest 0.017 fish/h + reported release 0.220 fish/h). Of the observed

harvested pike, 88% (51/58) were legal‐size therefore, the catch rate of legal‐length pike

was 0.015 fish/h. The reported protected‐length and the legal‐length release rates were

0.189 and 0.031 fish/h, respectively. The total pike catch rate was therefore 0.235 fish/h

(legal‐length harvest + reported protected‐length release + reported legal‐length

release). Following Sullivan (2003) and using the protected‐length to legal‐length ratio

from test angling, I estimated the release rate to be 0.093 pike/h. Thus, the estimated

total catch rate for pike was 0.110 fish/h. Data collected during the test angling are

listed in Appendix 12.

The recreational anglers using either the CLM or the PP reported the same harvest rates

(0.018 fish/h) and similar legal‐length release rates (0.030 fish/h and 0.034 fish/h,

respectively). The main difference was the release rate for protected‐length pike was

higher from PP (0.248 fish/h) than from the CLM (0.144 fish/h).

The range of age‐classes harvested by the sport fishery and sampled by the test angling

were similar. Age of the sport harvest ranged from 2 to 10 y and that of the test angling

18

ranged from 3 to 12 y (Figure 8). The higher‐density age‐classes as sampled by the test

angling were 4, 5, and 6 y. Ages 2, 3, 7, 8, and 9 were low‐density age‐classes. In

contrast, all the densities associated with the sport fishery sample were similar and low.

The sport fishery harvest was likely a biased sample due to the minimum size limit (630

mm TL, Figure 9). The mean age of the sport fishery and test angling were 7 (range 3 –

12, n = 55) and 4 y (range = 1 – 7, n = 108), respectively. Utilizing the test angling data,

six year‐classes were measurable (i.e., had a catch rate > 0.002 fish/h.

The length‐at‐age of pike was relatively high, with pike averaging 630 mm TL (593 mm

FL) by age 5 (Figure 10), indicating a fast rate of growth according to criteria in the

NPMRP (Berry 1999).

0.000

0.010

0.020

0.030

0.040

0.050

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Age (y)

Catch ra

te (fish

/h)

Sport fishery

Test angling

Figure 8. Age‐class distribution of pike harvested by the sport fishery and test

angling during the Cold Lake creel survey in 2005.

19

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

400 450 500 550 600 650 700 750 800 850 900 950 1000

Fork length (mm)

Catch ra

te (fish

/h)

Figure 9. Length‐class distribution of pike harvested during the Cold Lake creel

survey in 2005 (n = 58).

300

400

500

600

700

800

900

2 3 4 5 6 7 8 9 10 11 12 13 14 15Age (y)

Fork leng

th (m

m)

Figure 10. Length‐at‐age of northern pike harvested by anglers during the 2005 survey

(n = 55).

The mean weight of pike > 630 mm TL harvested during the 2005 creel survey was

2.373 kg (range 1.350 ‐ 5.650, n = 48). Based on criteria on Sullivan (1998), the low catch

20

rates along with a fast rate of growth and a high mean weight likely indicate a low

abundance of pike.

Of the pike sampled, the RSD for “stock‐quality” (35 ‐ 52 cm) was 53%. Forty‐four

percent of the sample was “quality” (53 ‐ 70 cm). No pike > 70 cm were sampled. The

PSD (proportion of pike sampled > 53 cm) was 44%. With the low catch rate, the

proportional and relative stock densities likely indicate a vulnerable fishery.

Success was low in catching legal‐length pike. Only 11% of the anglers interviewed

during the creel survey were successful. A Gini coefficient of 0.84 indicates a high level

of inequality in the catch of pike. Percent success and Gini metric include the anglers’

reported released pike. Since the catch was likely exaggerated, the percent success is

likely lower than calculated and the Gini coefficient is likely higher than calculated.

4.9 Summary

This creel survey was successful at quantifying angling pressure on lake trout, walleye

and pike, as well size distribution of these species in Cold Lake. I estimate that this

survey collected information from the majority of the recreational and guided anglers

utilizing the lake during the summer angling period. The use of the bootstrap

technique allowed for the analysis of this comparatively complex survey design, and

provided a measure of uncertainty around parameter estimates. Also, the measure of

uncertainty around the estimates can be used to identify areas that may require more or

less sampling effort in the future in addition to their applications to fisheries

management

Generally, the lake trout harvest consisted of fish approximately 671 mm (FL) in length

and weighing 4.443 kg on average. Ages of lake trout harvested ranged from 9 to 26 y.

Growth rate of lake trout was slow and the mean age was 15 y. During the creel

survey, all fish observed in the angler’s harvest were mature. Guided and recreational

anglers reported a harvest rate of 0.036 fish/h and protected‐length and legal‐length

release rates of 0.089 and 0.037 fish/h, respectively. Guided anglers reported higher

catch rates than recreational anglers.

21

Anglers harvested approximately 230 walleye during the 2005 survey. Approximately

35 and 65 walleye were harvested from the CLM and the PP, respectively. The yield of

walleye was approximately 0.015 kg/ha. The incidental mortality was approximately

39 fish. Overall, catch rate for walleye was low. Recreational anglers using the CLM

had similar harvest rates as recreational anglers using the PP. Recreational anglers

using the PP reported higher release rates than the recreational anglers using the CLM.

The guided anglers caught zero walleye. The calculated exaggeration factor may

indicate that fishing success was much poorer than reported.

According to the NPMRP classification, there was some variation in the assessment of

the pike fishery at Cold Lake during the 2005 creel survey. The age‐class distribution

was moderately broad with low densities. Catch rate of legal‐size fish was very low

and the catch rate for protected‐size pike was moderate. Growth was high with fish

reaching the minimum size limit in 5 y. No large fish (>70 cm TL) were caught. Sport

anglers had very poor success and a small portion of anglers harvested the majority of

fish.

22

5.0 LITERATURE CITED

Baccante, D. 1995. Assessing catch inequality in walleye angling fisheries. North

American Journal of Fisheries Management 15: 661‐665.

Berry, D.K. 1995. Alberta’s walleye management and recovery plan. Alberta

Environment Protection, Natural Resources Service, Number T/310, Edmonton,

Alberta, Canada. 32 pp.

Berry, D.K. 1999. Alberta’s northern pike management and recovery plan. Alberta

Environment Protection, Natural Resources Service, Number T/459, Edmonton,

Alberta, Canada. 22 pp.

Duffy, M., J. McNulty, and T. Mosindy. 2000. Identification of sex, maturity and gonad

condition of walleye Stizostedion vitreum vitreum. Ontario Ministry of Natural

Resources, Kenora, Ontario, Canada. 33 pp.

Gablehouse, D. 1984. A length‐categorization system to assess fish stocks. North

American Journal of Fisheries Management 4: 273‐285.

Gotelli, N.J., and A.M. Ellison. 2004. A primer of ecological statistics. Sinauer

Associates Inc., Sutherland, Massachusetts, USA. 510 pp.

Haddon, M. 2001. Modeling and quantitative methods in fisheries. Chapman and

Hall/CRC, Boca Raton, Florida. 406 pp.

Lee, W. C., and E. P. Bergersen. 1996. Influence of thermal and oxygen stratification

on lake trout incidental mortality. North American Journal of Fisheries

Management 16: 175‐181.

Loftus, A. J., W. W. Taylor, and M. Keller. 1988. An evaluation of lake trout (Salvelinus

namaycush) incidental mortality in the upper Great Lakes. Canadian Journal of

Fisheries and Aquatic Sciences. 45: 1473‐1479.

23

Mitchell, P., and E. Prepas. 1990. Atlas of Alberta Lakes. University of Alberta Press,

Edmonton, Alberta, Canada. 675 pp.

Mackay, W.C., G.R. Ash, and H.J. Norris (eds.). 1990. Fish ageing methods for Alberta.

R.L. & L. Environmental Services Ltd. in association with Alberta Fish and

Wildlife Division and University of Alberta, Edmonton. 113 pp.

Muoneke, M. I., and W. M. Childress. 1994. Incidental mortality: a review for

recreational fisheries. Reviews in Fisheries Science. 2(2): 123‐156.

Nelson, J. S., and M. J. Paetz. 1992. The Fishes of Alberta. University of Alberta Press,

Edmonton. 437pp Paul, A. J., J. R. Post, and J. D. Stelfox. 2003. Can anglers influence the abundance of

native and nonnative salmonids in a stream from the Canadian Rocky

Mountains? North American Journal of Fisheries Management 23:109–119.

Persons, S. E., and S. A. Hirsch. 1994. Incidental mortality of lake trout angled though

ice by jigging and set‐lining. North American Journal of Fisheries Management

14: 664‐668.

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. 371 pp.

Post, J.R., M. Sullivan, S. Cox, N.P. Lester, C.J. Walters, E.A. Parkinson, A.J. Paul, L.

Jackson, and B.J. Shuter. 2002. Canadaʹs recreational fisheries: The invisible

collapse? Fisheries. 27: 6‐17.

Scott, W.B., and E.J. Crossman. 1998. Freshwater Fishes of Canada. Galt House

Publications Ltd. Oakville, Ontario. 966 pp.

Shuter, B.J., M.L. Jones, R.M. Korver, and N.P. Lester. 1998. A general, life history

based model for regional management of fish stocks: The inland lake trout

24

(Salvelinus namaycush) fisheries of Ontario. Canadian Journal of Fisheries and

Aquatic Sciences. 55: 2161‐2177.

Sullivan, M.G. 2004. Computer simulation of sport fishery parameters. Alberta Fish

and Wildlife Division Unpublished Memorandum. 16 pp.

Sullivan, M.G. 2003. Exaggeration of walleye catches by Alberta anglers. North

American Journal of Fisheries Management 23:573‐580.

Sullivan, M.G. 1998. Northern management classification criteria for Alberta.

Unpublished. Alberta Fish and Wildlife Division Memorandum, Edmonton,

Alberta, Canada 11 pp.

25

6.0 APPENDICES

Appendix 1. An example of a creel survey field form.

26

Appendix 2. Daily summary data from the creel surveys at Cold Lake Marina (CLM) and the Cold Lake Provincial Park (PP) in 2005. Day codes: 1 = Monday, 2 = Tuesday, 3 = Wednesday, 4 = Wednesday, 5 = Friday, 6 = Saturday, 7 = Sunday, 8 = holiday. Species codes: LKTR = lake trout, WALL = walleye, NRPK = northern pike. Other codes: REL. LS = released legal‐size, REL. PL = released protected‐size.

Date Access #Anglers #Hours LKTR LKTR LKTR WALL WALL WALL NRPK NRPK NRPK

Site Kept Rel. LS Rel. PL Kept Rel. LS Rel. PL Kept Rel. LS Rel. PL5/22/05 PP 141 487.5 2 2 4 3 0 3 10 44 1075/23/05 PP 12 28.5 0 0 0 1 0 0 0 0 605/25/05 CLM 3 6.00 0 0 0 0 0 0 0 0 005/26/05 CLM 14 35.00 2 0 1 2 0 0 0 0 005/27/05 CLM 24 60.50 0 0 1 0 0 0 0 0 005/28/05 CLM 90 347.50 15 26 7 1 0 1 10 35 5805/29/05 CLM 67 216.50 2 3 9 1 1 2 3 10 236/4/05 PP 52 204.25 2 0 7 1 0 10 5 7 856/5/05 PP 56 183 3 1 13 1 0 2 7 5 316/7/05 PP 25 88.5 3 0 8 0 0 0 2 0 1906/08/05 CLM 46 161.75 3 7 7 2 2 7 4 1 2006/09/05 CLM 42 154.50 7 10 5 0 0 4 1 1 706/12/05 CLM 41 204.50 16 30 12 0 0 0 1 2 86/17/05 PP 30 96.5 2 1 4 0 0 0 3 1 176/19/05 PP 51 163.5 6 2 7 4 1 2 4 2 626/20/05 PP 52 179 7 0 22 0 0 1 1 1 206/21/05 PP 25 77 7 0 9 0 0 0 0 0 706/22/05 CLM 16 45.00 3 8 10 0 0 2 2 3 2806/23/05 CLM 1 0.00 0 0 0 0 0 0 0 0 006/24/05 CLM 43 171.50 12 22 28 0 0 0 3 12 3706/25/05 CLM 67 314.50 22 23 48 0 6 4 1 7 487/2/05 PP 2 9 0 0 0 0 0 0 0 0 107/4/05 PP 53 192 10 1 23 4 0 17 3 6 497/5/05 PP 42 128.5 6 0 18 1 0 0 8 1 2707/06/05 CLM 44 130.75 7 23 19 1 0 0 2 0 1807/07/05 CLM 33 99.00 8 2 3 0 0 0 3 3 39

27

Appendix 2 continued.

Date Access #Anglers #Hours LKTR LKTR LKTR WALL WALL WALL NRPK NRPK NRPKSite Kept Rel. LS Rel. PL Kept Rel. LS Rel. PL Kept Rel. LS Rel. PL

07/08/05 CLM 60 225.00 15 8 20 3 0 8 4 0 3607/09/05 CLM 81 307.50 14 13 32 0 0 0 11 3 417/15/05 PP 25 100 4 0 10 0 0 3 1 7 327/16/05 PP 8 19 0 1 5 0 0 0 0 3 97/17/05 PP 73 213 0 0 0 0 0 1 3 4 10307/20/05 CLM 23 78.00 3 4 16 0 0 0 1 1 137/21/05 PP 2 11 0 0 0 0 0 0 0 2 607/22/05 CLM 37 132.00 5 4 9 0 0 0 3 2 237/22/05 PP 3 10.5 0 0 0 0 0 0 1 0 37/30/05 PP 87 321 8 0 25 1 0 6 5 14 407/31/05 PP 80 337.5 6 8 35 0 0 17 1 3 608/2/05 PP 25 68.5 0 0 0 0 0 0 0 1 2208/03/05 CLM 5 5.00 0 0 0 0 0 0 0 0 008/04/05 CLM 62 257.00 13 16 40 0 0 0 1 1 2408/05/05 CLM 64 184.75 6 6 16 0 0 0 4 1 2208/06/05 CLM 79 340.00 11 13 58 0 0 0 2 29 8008/07/05 CLM 26 94.00 1 0 12 0 0 0 1 1 28/12/05 PP 20 35 0 0 0 0 0 0 0 0 158/16/05 PP 16 52.5 0 2 13 0 0 0 0 1 1408/17/05 CLM 1 0.00 0 0 0 0 0 0 0 0 008/19/05 CLM 23 69.50 3 0 26 0 0 1 3 1 1408/21/05 CLM 68 288.50 10 10 30 0 0 0 10 5 25

28

Appendix 3. Data collected during 22 Ratio‐of‐use (ROU) surveys conducted during the summer creel survey at Cold Lake 2005. Codes: LKTR = lake trout, WALL = walleye, NRPK = northern pike, Rel = fish released, CLM = Cold Lake Marina, PP = Cold Lake Provincial Park, ROU = Ratio‐of‐use.

#Anglers #hour LKTR LKTR WALL WALL NRPK NRPK Kept Rel. Kept Rel. Kept Rel.

Other 171 404 14 35 2 6 9 114

CLM + PP 493 1246.5 51 204 2 7 26 224

Total 664 1650.5 65 239 4 13 35 338

ROU 0.74 0.76 0.78 0.85 0.50 0.54 0.74 0.66 mean ROU = 0.69 SE = 0.04 n = 8

29

Appendix 4. Standardized probability density function of the estimated number of anglers at Cold Lake during the 2005 survey. The estimate is the mean of the bootstrap estimates.

0.0

0.2

0.4

0.6

0.8

1.0

6000 7250 8500 9750 11000 12250

Number of anglers

Stan

dardized proba

bility

func

tion

Appendix 5. Standardized probability density function of the number of angling hours estimated at Cold Lake during the 2005 survey. The estimate is the mean of the bootstrap estimates.

0.0

0.2

0.4

0.6

0.8

1.0

18000 28000 38000 48000

Number angling hours (h)

Stan

dardized proba

bility

func

tion

30

Appendix 6. Standardized probability density function of the angling pressure (h/ha) estimated at Cold Lake during the 2005 survey. The estimate is the mean of the bootstrap estimates.

0.0

0.2

0.4

0.6

0.8

1.0

0.50 0.70 0.90 1.10 1.30Angling pressure (h/ha)

Stan

dardized proba

bility

func

tion

Appendix 7. Standardized probability density function of the number of lake trout harvested from Cold Lake during the 2005 survey. The estimate is the mean of the bootstrap estimates.

0.0

0.2

0.4

0.6

0.8

1.0

400 650 900 1150 1400 1650 1900Number lake trout harvested

Stan

dardized proba

bility

func

tion

31

Appendix 8. Standardized probability density function of the yield of lake trout from Cold Lake during the 2005 survey. The estimate is the mean of the bootstrap estimates.

0.0

0.2

0.4

0.6

0.8

1.0

0 0.05 0.1 0.15 0.2 0.25 0.3Yield of lake trout (kg/ha)

Stan

dardized proba

bility

functio

n

Appendix 9. Standardized probability density function of the number of lake trout associated with incidental mortality (IM) simulations (5%, 10% 15%, grey lines) and the total harvest of lake trout (harvest + incidental mortality, thinner black lines) from Cold Lake during the 2005 survey. The heavy black line represents the harvest of lake trout without any associated incidental mortality (see Appendix 7). The estimates are the means of the bootstrap estimates

0.0

0.2

0.4

0.6

0.8

1.0

0250

500

750

1000

1250

1500

1750

2000

2250

2500

2750

3000

Lake trout mortality (# fish)

Stan

dardized probability

functio

n

Harvest

5% IM

10% IM

15% IM

+5% IM

+10% IM

+15% IM

32

Appendix 10. Standardized probability density function of the mean weight of lake trout harvested during the 2005 survey (mean = 4,443 grams, n = 160). The estimate is the mean of the bootstrap estimates.

0.0

0.2

0.4

0.6

0.8

1.0

3800 4000 4200 4400 4600 4800 5000Mean weight of lake trout (g)

Stan

dardized proba

bility

func

tion

33

Appendix 11. Biological data collected from sport angler harvested fish at Cold Lake in the summer of 2005. Species code: LKTR = lake trout, WALL = walleye, NRPK = northern pike. Codes: FL = fork length, WT = weight. Sex code: M = male, F = female.

Date Sample# Species FL (mm) WT (g) Sex Maturity Age (y) 5/21/05 1 WALL 734 F Mature 14 5/22/05 2 LKTR 650 4000 M Mature 11

3 WALL 448 1100 6 4 WALL 550 1750 10 5 WALL 685 2500 11 6 NRPK 595 1700 M Mature 6 7 NRPK 605 1750 5 8 NRPK 640 2250 6 9 NRPK 720 2150 8 10 NRPK 750 3500 7 11 NRPK 614 1950 7 12 NRPK 635 2000 7 13 NRPK 575 1750 6 14 YLPR 321 500 M Mature 8

5/23/05 15 WALL 711 4000 F Mature 21 5/26/05 16 LKTR 594 2900 F Mature 12

17 LKTR 635 3150 F Mature 13 18 WALL 602 2250 F Mature 9 19 WALL 555 F Mature 8

5/27/05 20 LKTR 615 3250 F Mature 12 5/28/05 21 LKTR 785 7500 F Mature 24

22 LKTR 803 7250 M Mature 26 23 LKTR 735 6600 F Mature 17 24 LKTR 670 4100 F Mature 19 25 LKTR 590 3250 M Mature 12 26 LKTR 725 4300 F Mature 17 27 LKTR 665 4250 F Mature 16 28 LKTR 683 4250 15 29 LKTR 690 4500 F Mature 18

34

Appendix 11 continued. Date Sample# Species FL (mm) WT (g) Sex Maturity Age (y) 6/4/05 30 LKTR 602 3050 F Mature 11 31 LKTR 619 F 13 32 WALL 606 2400 F Mature 15 33 NRPK 730 2850 8 34 NRPK 631 1850 M Mature 6 35 NRPK 701 2550 M Mature 8 36 NRPK 637 1750 F Mature 6

6/5/05 37 LKTR 652 4350 F Mature 13 38 LKTR 600 3000 F Mature 10 39 LKTR 655 4050 F Mature 40 WALL 727 3400 F Mature 19 41 NRPK 657 1900 F Mature 6 42 NRPK 750 3100 F Mature 7 43 NRPK 620 1550 F Mature 6 44 NRPK 647 2100 M Mature 8 45 NRPK 686 2350 F Mature 5 46 NRPK 610 1650 M Mature 5 47 NRPK 648 1950 F Mature 7

6/7/05 48 LKTR 672 4750 F Mature 15 49 LKTR 635 3850 M Mature 14 50 LKTR 705 4600 F Mature 19 51 NRPK 665 2150 F Mature 7 52 NRPK 664 2200 F Mature

6/8/05 53 LKTR 715 4300 F Mature 17 54 LKTR 704 4950 F Mature 16 55 LKTR 635 3700 F Mature 11 56 WALL 570 2250 M Mature 8 57 WALL 498 1300 F Mature 5 58 NRPK 701 2300 F Mature 7 59 NRPK 690 2500 F Mature 8 60 NRPK 656 2050 F Mature 7

6/9/05 61 LKTR 696 5400 M Mature 62 LKTR 601 3050 F Mature 14 63 LKTR 667 M Mature 16 64 LKTR 614 3000 F Mature 11

35

Appendix 11 continued. Date Sample# Species FL (mm) WT (g) Sex Maturity Age (y) 65 LKTR 695 3700 M Mature 12 66 LKTR 695 4950 F Mature 14 67 LKTR 693 4800 F Mature 17 68 NRPK 830 3800 F Mature 11

6/12/05 69 LKTR F Mature 24 70 LKTR 5250 F Mature 16 71 LKTR 605 3450 F Mature 10 72 LKTR 652 3500 M Mature 13 73 LKTR 750 6150 F Mature 17 74 LKTR 630 3450 F Mature 13 75 LKTR 714 5250 F Mature 16 76 LKTR 735 5200 77 LKTR 655 11 78 LKTR 720 17 79 LKTR 660 4350 M Mature 16 80 LKTR 655 15 81 LKTR 641 3800 M Mature 15 82 LKTR 696 5250 F Mature 14 83 LKTR 740 6400 19 84 LKTR 772 5150 M Mature 24 85 LKTR 643 3500 M Mature 14 86 NRPK 715 2350 F Mature 8

6/17/05 87 LKTR 621 3350 F Mature 11 88 LKTR 650 3800 F Mature 15 89 NRPK 531 1200 4 90 NRPK 560 1300 4 91 NRPK 600 1350 M Mature 5

6/19/05 92 LKTR 650 4500 M Mature 15 93 LKTR 671 4400 M Mature 16 94 LKTR 735 5150 M Mature 20 95 LKTR 577 2800 M Mature 11 96 LKTR 613 3300 F Mature 10 97 LKTR 550 2350 M Mature 9 98 WALL 510 1600 M Mature 8

36

Appendix 11 continued. Date Sample# Species FL (mm) WT (g) Sex Maturity Age (y) 99 WALL 587 2200 F Mature 8 100 WALL 550 1950 F Mature 7 101 WALL 491 1400 M Mature 7 102 NRPK 835 4300 F Mature 10 103 NRPK 614 1800 M Mature 9 104 NRPK 740 3000 F Mature 8 105 NRPK 603 1850 M Mature 7

6/20/05 106 LKTR 610 3200 F Mature 11 107 LKTR 650 3500 M Mature 13 108 LKTR 623 3400 M Mature 12 109 LKTR 625 3300 12 110 LKTR 665 4350 M Mature 111 LKTR 718 4500 F Mature 15 112 LKTR 630 3500 F Mature

6/21/05 113 LKTR 613 2950 M Mature 114 LKTR 580 2700 M Mature 9 115 LKTR 712 5400 F Mature 116 LKTR 622 3000 M Mature 10 117 LKTR 602 2750 F Mature 11 118 LKTR 630 3400 F Mature 15 119 LKTR 728 4950 M Mature 19

6/22/05 120 NRPK 690 1500 9 121 NRPK 645 1750 F Mature 7

6/23/05 122 LKTR 723 4850 M Mature 22 6/24/05 123 LKTR 725 4750 F Mature 21

124 LKTR 630 4200 F Mature 13 125 LKTR 680 3800 F Mature 17 126 LKTR 638 3350 M Mature 14 127 LKTR 710 5350 M Mature 17 128 LKTR 703 4650 M Mature 18 129 LKTR 617 3400 M Mature 12 130 LKTR 735 5950 F Mature 19 131 NRPK 635 1950 F Mature 6

6/25/05 132 LKTR 685 4150 M Mature

37

Appendix 11 continued. Date Sample# Species FL (mm) WT (g) Sex Maturity Age (y) 133 LKTR 735 5150 F Mature 20 134 LKTR 660 3850 M Mature 18 135 LKTR 651 3900 M Mature 15 136 LKTR 715 5580 F Mature 137 LKTR 754 6300 F Mature 20 138 LKTR 770 6850 F Mature 21 139 LKTR 655 3750 F Mature 11 140 LKTR 5250 F Mature 15 141 LKTR 660 5000 F Mature 15 142 LKTR 4400 M Mature 11 143 LKTR 675 4500 F Mature 15 144 LKTR 706 4400 M Mature 19 145 LKTR 650 4650 M Mature 16 146 LKTR 650 4200 F Mature 12 147 LKTR 637 3600 F Mature 11 148 LKTR 685 5900 M Mature 13 149 LKTR 5200 F Mature 16

7/4/05 150 LKTR 675 4000 F Mature 15 151 LKTR 661 3600 M Mature 11 152 LKTR 697 3400 F Mature 16 153 LKTR 675 5000 F Mature 14 154 WALL 2300 7 155 WALL 4150 15 156 WALL 1500 6 157 WALL 3850 13 158 NRPK 678 2000 M Mature 8

7/5/05 159 LKTR 640 4000 F Mature 13 160 LKTR 678 5100 M Mature 161 NRPK 620 1700 F Mature 6 162 NRPK 475 850 M Mature 3 163 NRPK 541 1250 M Mature 4 164 NRPK 503 900 M Mature 4 165 NRPK 523 1050 F Mature 4

7/6/05 166 LKTR 715 5450 17

38

Appendix 11 continued. Date Sample# Species FL (mm) WT (g) Sex Maturity Age (y) 167 LKTR 637 3400 F Mature 13 168 LKTR 600 3200 M Mature 11 169 LKTR 603 2800 M Mature 12

7/7/05 170 LKTR 765 4450 F Mature 13 171 LKTR 675 4050 M Mature 18 172 LKTR 748 5250 M Mature 21 173 LKTR 665 3950 174 LKTR 712 5350 F Mature 17 175 LKTR 719 4150 M Mature 16 176 LKTR 714 3950 M Mature 15 177 LKTR 630 10

7/8/05 178 LKTR 719 5200 15 179 LKTR 671 5000 M Mature 16 180 LKTR 780 5200 M Mature 18 181 LKTR 735 5500 M Mature 23 182 LKTR 635 3850 F Mature 10 183 LKTR 586 3350 M Mature 11 184 NRPK 763 F Mature 8 185 NRPK 635 2050 F Mature 5

7/9/05 186 LKTR 715 5400 F Mature 17 187 LKTR 660 5300 F Mature 15 188 LKTR 715 5400 M Mature 16 189 LKTR 750 7000 M Mature 16 190 LKTR 732 6400 F Mature 17 191 LKTR 629 3300 M Mature 13 192 LKTR 630 3200 F Mature 11 193 LKTR 733 5150 M Mature 20 194 LKTR 721 4300 M Mature 15 195 NRPK 685 2400 F Mature 8 196 NRPK 693 2500 F Mature 5 197 NRPK 635 2300 M Mature 7 198 NRPK 710 3000 F Mature 7 199 NRPK 893 5950 F Mature 12

7/10/05 200 WALL 580 2050 M Mature 8

39

Appendix 11 continued. Date Sample# Species FL (mm) WT (g) Sex Maturity Age (y) 7/15/05 201 LKTR 713 6300 F Mature

202 LKTR 639 3600 M Mature 13 203 LKTR 690 4700 M Mature 15 204 LKTR 625 4050 F Mature 15 205 NRPK 701 2300 F Mature 8

7/17/05 206 NRPK 610 1950 F Mature 5 207 NRPK 675 2350 M Mature 7 208 NRPK 623 1700 F Mature 6

7/19/05 209 WALL 659 12 210 WALL 492 8 211 WALL 615 F Mature 8

7/20/05 212 LKTR 710 5450 F Mature 17 213 LKTR 725 6550 F Mature 16 214 LKTR 712 6100 F Mature 16 215 NRPK 640 2000 7

7/22/05 216 LKTR 740 6350 M Mature 19 217 LKTR 724 6050 F Mature 15 218 LKTR 638 4500 F Mature 13 219 LKTR 685 4650 15 220 NRPK 878 4800 10

7/30/05 221 LKTR 740 6100 M Mature 17 222 LKTR 718 4800 M Mature 15 223 LKTR 620 3200 M Mature 11 224 LKTR 637 3900 F Mature 14

7/31/05 225 LKTR 665 4100 F Mature 12 226 LKTR 630 4000 F Mature 13

8/4/05 227 LKTR 635 4500 M Mature 15 228 LKTR 640 4500 M Mature 11 229 LKTR 690 5000 M Mature 17 230 LKTR 697 5200 M Mature 18 231 LKTR F Mature 16 232 LKTR 720 5900 F Mature 15 233 LKTR M Mature 13 234 LKTR 665 4100 F Mature 15

40

Appendix 11 continued. Date Sample# Species FL (mm) WT (g) Sex Maturity Age (y) 8/5/05 235 LKTR 650 4000 F Mature 15 236 LKTR 690 6400 M Mature 18 237 LKTR 615 4150 F Mature 11 238 LKTR 604 3200 M Mature 11 239 NRPK 742 3150 F Mature 7

8/6/05 240 LKTR 721 5450 M Mature 19 241 LKTR 740 M Mature 242 LKTR 691 F Mature 15 243 LKTR 603 3250 M Mature 12 244 LKTR 590 3100 F Mature 10 245 LKTR 678 4400 M Mature 17 246 LKTR 715 5400 M Mature 16 247 LKTR 610 3100 M Mature 11

8/7/05 248 LKTR 673 4150 M Mature 14 8/13/05 249 LKTR 674 4750 M Mature 14 8/19/05 250 LKTR 750 4500 F Mature 23

251 LKTR 635 3500 F Mature 14 252 LKTR 715 4800 M Mature 17

8/20/05 253 NRPK 653 5 254 NRPK 614

41

Appendix 12. Biological data collected from fish sampled during test angling at Cold Lake, 2005. Codes: NRPK = northern pike, LKTR = lake trout, FL = fork length.

Date Sample# Species FL mm 5/21/05 1 NRPK 485

2 NRPK 699 3 NRPK 544 4 NRPK 502 5 NRPK 578 6 NRPK 526 7 NRPK 523

6/06/05 8 NRPK 465 9 NRPK 446 10 NRPK 535 11 NRPK 428 12 NRPK 535 13 NRPK 514 14 NRPK 578 15 NRPK 513

6/10/05 16 NRPK 431 17 NRPK 538 18 NRPK 526 19 NRPK 496 20 NRPK 499 21 NRPK 695 22 NRPK 596 23 NRPK 551 24 NRPK 475 25 NRPK 514 26 NRPK 545 27 NRPK 475

7/02/05 28 NRPK 463 29 NRPK 521 30 NRPK 530 31 NRPK 539 32 NRPK 481 33 NRPK 488 34 NRPK 534 35 NRPK 536

42

Appendix 12. Continued.

Date Sample# Species FL mm 36 NRPK 497

7/18/05 37 NRPK 466 38 NRPK 321 39 NRPK 518 40 NRPK 474 41 NRPK 522 42 NRPK 550 43 NRPK 577 44 NRPK 615 46 NRPK 283 47 NRPK 294

7/21/05 48 NRPK 697 49 NRPK 518 50 NRPK 482 51 NRPK 470 52 NRPK 490 53 NRPK 530 54 NRPK 605 55 NRPK 546 56 NRPK 495

7/29/05 57 NRPK 494 59 NRPK 475 60 NRPK 516 61 NRPK 525 62 NRPK 605 63 NRPK 590

8/14/05 64 NRPK 553 65 NRPK 465 66 NRPK 528 67 NRPK 480 68 NRPK 515 69 NRPK 493 70 NRPK 473 71 NRPK 507 72 NRPK 584 73 NRPK 464 74 NRPK 471

43

Appendix 12. Continued.

Date Sample# Species FL mm 75 NRPK 576 76 NRPK 530 77 NRPK 508


8/18/05 84 NRPK 512 85 NRPK 480 86 NRPK 537 87 NRPK 550 88 NRPK 571 89 NRPK 607 90 NRPK 582 91 NRPK 528 92 NRPK 475 93 NRPK 528 94 NRPK 452 95 NRPK 515 96 NRPK 506 97 NRPK 542 98 NRPK 486 99 NRPK 552 100 NRPK 535 101 NRPK 645

6/16/05 102 LKTR 595 103 LKTR 630 104 NRPK 575


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