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Report 1.2.1: Changes Between Historic and Current Fish Relative Abundance and Size Within Selected Foothills Model Forest Watersheds

Prepared by Richard McCleary, Cameron Nelin, Chantelle Bambrick, Scott Wilson and Chad Sherburne Fish and Watershed Research Program Foothills Model Forest March 19, 2003


Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Foothills Model Forest Publication Disclaimer The views, statements and conclusions expressed, and the recommendations made in this report are entirely those of the author(s) and should not be construed as statements or conclusions of, or as expressing the opinions of the Foothills Model Forest, or the partners or sponsors of the Foothills Model Forest. The exclusion of certain manufactured products does not necessarily imply disapproval, nor does the mention of other products necessarily imply endorsement by the Foothills Model Forest or any of its partners or sponsors.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Acknowledgements In 2001, this project was funded through a partnership that included the Alberta Conservation Association (ACA), Weldwood of Canada Ltd. (Hinton Division), and the Canadian Forest Service. The funding from Weldwood was made available through the Forest Resources Improvement Program. Additional support for this Foothills Model Forest project was received through Alberta Sustainable Resource Development and Jasper National Park. Mike Blackburn organized the literature review and re-sampling schedule. The 2001 field crew that participated in re-sampling inventories was Jason Blackburn and Tyler Muhly. Jason Blackburn developed the database for storage of the historic and current survey data. Dr. Hans Zuuring, Professor of Forestry Biometry, Director of Qualitative Services Group, School of Forestry, University of Montana provided a review of the statistical methods used to compare catch rates and proportion of catchable size fish. Cameron Nelin completed analysis of the historic and re-sample fisheries data. George Sterling provided a review of an earlier version of this report. Fran Hanington provided editorial review of the final report.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Abstract The purpose of this study was to determine if the replication of historical fish inventories could provide any indication of the effects of more recent human-use activities on fish populations and fish size within twelve watersheds in the Foothills Model Forest. In addition, we attempted to develop two indicators of fish population sustainability that could be incorporated into other longer-term Foothills Model Forest studies. In 2001, a search for historical studies identified a total of 59 reports that had been completed between 1960 and 1992 in ten of the study area watersheds. From these 59 reports, only 33 sites were identified as candidates for re-survey. Numerous historical studies did not describe the sampling methodology with sufficient information to permit replication. Details of electrofishing effort and individual fork lengths were often excluded. In the late summer and fall of 2001, current information was collected that allowed a comparison of data at 21 sites. Information from ten of the historic-current pairs was suitable to compare catch rates within four watersheds. Significant differences in catch rates were detected in two of those basins. Information from four of the historic-current pairs was suitable to compare the changes in proportion of catchable size sport fish. Each of these four sites was from a different watershed. The findings were compared to the results from an overview of land-use and an overview of changes in fishing regulations and potential explanations were provided. We observed several changes in the indicators that corresponded to changes in angling regulations, however, no changes were detected that related to increases in land-use. More detailed studies of Rainbow Trout in MacKenzie Creek may be required to explain observed changes in that watershed. Follow-up survey sites were identified and recommendations for future Foothills Model Forest before-after type monitoring exercises were presented.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Table of Contents Foothills Model Forest Publication Disclaimer ............................................................................... i Acknowledgements......................................................................................................................... ii Abstract .......................................................................................................................................... iii Table of Contents........................................................................................................................... iv List of Figures ................................................................................................................................. v List of Tables .................................................................................................................................. v 1 Introduction............................................................................................................................. 1 2 Methods................................................................................................................................... 1 2.1 Study Area ...................................................................................................................... 1 2.2 Historic Data / Literature Search .................................................................................... 2 2.3 Data Management ........................................................................................................... 3 2.4 Site Selection .................................................................................................................. 3 2.5 Field Surveys .................................................................................................................. 3 2.6 Data Analysis .................................................................................................................. 4 3 Results..................................................................................................................................... 6 3.1 Summary by Watershed.................................................................................................. 6 3.1.1 Lambert Creek ........................................................................................................ 6 3.1.2 MacKenzie Creek.................................................................................................... 9 3.1.3 Moon Creek .......................................................................................................... 11 3.1.4 Pinto Creek............................................................................................................ 11 3.1.5 Solomon Creek...................................................................................................... 12 3.1.6 Upper Erith River.................................................................................................. 14 3.2 Summary for all Monitoring Watersheds ..................................................................... 15 3.2.1 Statistical Analysis of Differences in Historic and Current Survey Catch Rates . 15 3.2.2 Changes in Proportion of Catchable Size Fish ..................................................... 16 4 Discussion ............................................................................................................................. 17 4.1 Relationships Between Changes in Catch Rates, Angling Regulations and Land-use. 17 4.2 Relationships Between Changes in Proportion of Catchable Size Fish and Land-use . 19 4.3 Considerations from Observed Relationships............................................................... 19 4.4 Considerations for Future Foothills Model Forest Monitoring Efforts ........................ 19 4.4.1 Lack of Habitat Data............................................................................................. 20 4.4.2 Catch per Unit Effort Calculations from Backpack Electrofishing ...................... 20 4.4.3 Fish Identification ................................................................................................. 20 4.4.4 Statistical Limitations ........................................................................................... 20 4.4.5 Electrofishing and Fish Spawning Seasons .......................................................... 21

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

List of Figures Figure 1. Monitoring watersheds within the Foothills Model Forest. ........................................... 2 Figure 2. A comparison of historic and current surveyed rainbow trout captured at Location 971 in the Lambert Creek watershed. ............................................................................................ 8 Figure 3. A comparison of historic and current surveyed rainbow trout captured at Location 962 in the MacKenzie Creek watershed. ..................................................................................... 10 Figure 4. A comparison of historic and current surveyed brook trout captured at Location 131 in the Solomon Creek watershed. ............................................................................................. 13 Figure 5. A comparison of historic and current surveyed rainbow trout captured at Location 714 in the Upper Erith River watershed. ..................................................................................... 14

List of Tables Table 1. Summary of fish species represented in selected monitoring watersheds. ....................... 6 Table 2. Catch rate comparisons for the Lambert Creek watershed (Locations 926, 927, and 972). ........................................................................................................................................ 7 Table 3. Number of catchable size sport fish (>149mm) captured in the Lambert Creek watershed. ............................................................................................................................... 8 Table 4. Proportion of catchable size sport fish (> 149mm) comparison for the Lambert Creek watershed. ............................................................................................................................... 9 Table 5. Catch rate comparisons for the MacKenzie Creek watershed (Locations 432 and 961). 9 Table 6. Number of catchable size sport fish (>149mm) captured in the MacKenzie Creek watershed. ............................................................................................................................. 10 Table 7. Proportion of catchable size sport fish (> 149mm) comparison for the MacKenzie Creek watershed.................................................................................................................... 10 Table 8. Catch rate comparisons for the Moon Creek watershed (Locations 8 and 19).............. 11 Table 9. Catch rate comparisons for the Pinto Creek watershed (Locations 88 and 978)........... 12 Table 10. Number of catchable size sport fish (>149mm) captured in the Solomon Creek watershed. ............................................................................................................................. 13 Table 11. Proportion of catchable size sport fish (> 149mm) comparison for the Solomon Creek watershed. ............................................................................................................................. 13 Table 12. Number of catchable size sport fish (>149mm) captured in the Upper Erith River watershed. ............................................................................................................................. 14 Table 13. Proportion of catchable size sport fish (> 149mm) comparison for the Upper Erith River watershed. ................................................................................................................... 15 Table 14. Summary of statistical analysis of differences in historic and current survey catch rates. ...................................................................................................................................... 16 Table 15. Summary of Size Distribution for all selected monitoring watersheds. ...................... 17 Table 16. Summary of changes in catch rates, fish size, angling regulations, harvest and road development in monitoring watersheds of the FMF. ............................................................ 18

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

1

Introduction We selected two different before-after type strategies to learn about the potential effects

of human-use activities on fish populations. The first strategy relied on annual population estimation at a small number of sites. This approach builds on the Tri - Creeks study. Its strength is the continuity of the dataset from year to year. Its weakness, however, is the small sample size that results in a poor representation of the human-use activities and ecological conditions within the study area. The findings from this long-term monitoring effort are described in Report 1.2.2: Long-term changes in relative abundance of Rainbow Trout at selected sites within the Foothills Model Forest. In our second strategy, we postulated that if a large enough number of government and industry-related inventories had been completed within the study area watersheds, some valuable information could be gained by replicating the historic surveys. The strength of this approach was that a larger number of sample sites would be more representative of the range of human-use activities and ecological conditions within the study area. Its major weakness was that fish populations are highly variable from year to year and without a continuous population history, the ability to arrive at definitive conclusions would be limited. Nonetheless, we determined that the strategy warranted investigation and our findings are described in this report. Concurrent to this study, the Foothills Model Forest (FMF) was in the process of identifying a set of biodiversity indicators to support a long-term effort to measure forest resource sustainability (FMF 2003). Any of the parameters from this study that provide meaningful information related to the sustainability of aquatic resources would be candidates for continued monitoring as part of the ongoing FMF indicators program.

2

Methods

2.1 Study Area The study area included 12 watersheds within the Foothills Model Forest (Figure 1). With the abundance of data from a number of different years, the Tri-Creeks data provided a unique opportunity to study trends in fish populations at specific sites over time. As a result, these data were better suited to other analysis methods addressed in a separate report.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Figure 1. Monitoring watersheds within the Foothills Model Forest.

2.2 Historic Data / Literature Search The first step in this project was to conduct a literature search of all past fisheries projects completed within the study area watersheds. Data sources included: •

Alberta Sustainable Resource Development, Fish and Wildlife Division, Historic Phase II reports

Alberta Environment Fisheries Management Information System database

Northern Alberta Institute of Technology forestry reports, and the

Alberta Sustainable Resource Development library located in Edson.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

2.3 Data Management A database was developed in Microsoft Access to store and manage the historic data. Fields in the database included site location, sample methods, sample dates, sampling effort, species composition, individual fish fork lengths and weights, and surveyed stream lengths and widths. The location information from the historic reports was presented in a variety of ways including UTM coordinates, legal land description, maps, or written descriptions from the old reports. This information was interpreted and survey sites were mapped as point data in Arcview 3.2 (ESRI 1999). UTM coordinates were then generated for each point using an Arcview extension tool (ESRI 1999). These confirmed locations were then entered into the database.

2.4 Site Selection Once the historic sites were mapped, comparisons were made between historic sites and existing FMF inventory sites to determine if the FMF had recently surveyed any of the historic sites. Historic sites and FMF sites were considered to be the same location if they (1) were within close spatial proximity, (2) were located in a stream reach with similar slope, and drainage area size, (3) had the same stream order, and (4) were not bisected by a potential barrier such as a road or waterfall. Where a historic site and an FMF site were at the same location, the sample dates were compared to see if they were from the same season. This seasonal timing was broken down into three sampling seasons; spring, summer, and fall consisting of May-June-July, July-August, and August-September-October respectively.

2.5 Field Surveys Where a historic site and an FMF site shared the same location and sampling season, no further sampling was necessary to establish a historic-current pair. Those historic sampling sites lacking a current pair were selected for inventory during the 2001 field season. Field staff used detailed maps displaying site locations and UTM co-ordinates to determine site access and collected fish and habitat data according to standard FMF inventory methods (McCleary et al. 2001). Field surveys were conducted at a total of 24 sites from August 9, 2001 to October 4, 2001. Foothills Model Forest

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

2.6 Data Analysis The two most similar sampling dates were selected when more than one survey had been completed in a year. 2.6.1

Statistical Analysis of Differences in Historic and Current Survey Catch Rates from a

Number of Sites within an Individual Basin To test the null hypothesis that the mean historic catch rate wquals the mean current catch rate, we used a two-tailed paired t-test (α = 0.20), (Equations 1 and 2). Fish species in a unique paired survey were only included in this paired comparison if a sample of at least five fish were captured in either the historic survey or the current survey. The statistics were calculated with SPSS (v10.0) statistical software. The results of the paired t-tests were summarized in tables.

Equation 1:

Equation 2:

2.6.2

Ho: µ historic catch rate = µ current catch rate

2P (T ≥ |t|)

Changes in Proportion of Catchable Size Fish Providing an opportunity for angling is an important objective of both fishery and fish

habitat managers. Previous studies in both of these disciplines have used a 150 mm cut-off for the minimum size fish to be sufficient for sport fishing (Koning and Keeley 1997). In addition, for resident rainbow trout populations, maintaining a sufficient number of fish of this size could also provide an indicator of the spawning or reproductive capacity of a population. Previous studies that report the proportion of fish of catchable size did not include a statistical analysis. However, such methods are used in other natural sciences applications. To test the null hypothesis that the proportion of catchable size sport fish (> 149mm) on the historic date and current date were equal (equations 3 and 4), we used two-tailed Z-tests (α = 0.20) as calculated in Equations 5-7 (Moore and McCabe 1993). Fish species in a unique paired survey were only included in the comparison if a sample of at least ten fish greater than 50 mm fork length were captured in both the historic survey and the current survey.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

p1 = p2

Equation 3:

Where p1 = proportion of historic population > 149mm p2 = proportion of current population > 149mm Equation 4:

2P (Z ≥ |z|)

Z

Equation 5:

p

=

p1 − p 2

σ

p1 − p 2

Where: p1 = proportion of sample 1 p2 = proportion of sample 2

σ p1 − p2 = Standard error of the difference of proportions

Equation 6:

σ p1 − p2 =

Where:

Equation 7:

 n + n2   pˆ (1 − p ) 1  n1n2 

pˆ = The pooled estimate

pˆ =

n1 p1 + n 2 p 2 n1 + n2

An increase in the proportion of fish of catchable size would be considered a positive indicator only if this occurred with the maintenance of juvenile size classes. The case where an increase in the proportion of catchable size occurs while juvenile fish are poorly represented would be indicative of recruitment failure. Therefore, in order to confirm the presence of juvenile size classes, fork length frequency distributions were generated for all cases that met the criteria for the proportional analysis (i.e. At least 10 fish greater than 49 mm fork length were captured). Based on the findings from previous studies in the region, fish with a fork length of a minimum of 120 mm were considered adults and smaller fish were considered juveniles.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

3

Results A total of 33 sites suitable for replication were identified from a total of 59 historic

reports within 10 of the 12 watersheds (Appendix 1). Of the 33 historic sites suitable for replication, the FMF was able to obtain data to form historic-current pairs at 21 sites. Historiccurrent paired surveys were not obtained for the Emerson and Lynx Creek watersheds. Data was sufficient for an analysis of catch rates in four watersheds including Lambert, MacKenzie, Moon, and Pinto Creek. Data was sufficient for an analysis of changes in proportion of catchable size fish at a total of four sites from four watersheds including Lambert, MacKenzie, Solomon, and the Upper Erith River. A total of 14 fish species were captured between the historic and current surveys (Table 1). Table 1. Summary of fish species represented in selected monitoring watersheds.

Species Bull Trout Rainbow Trout Brook Trout Arctic Grayling Burbot Mountain Whitefish White Sucker Longnose Sucker Spoonhead Sculpin Brook Stickleback Finescale Dace Pearl Dace Trout-perch Northern Pike

Scientific Name Salvelinus confluentus Onchorhynchus mykiss Salvelinus fontinalis Thymallus arcticus Lota lota Prosopium williamsoni Catostomus commersoni Catostomus catostomus Cottus recei Culaea inconstans Phoxinus neogaeus Margariscus margarita Percopsis omiscomaycus Esox lucius

3.1

Summary by Watershed

3.1.1

Lambert Creek

Abbreviation BLTR RNTR BKTR ARGR BURB MNWH WHSC LNSC SPSC BRST FNDC PRDC TRPR NRPK

3.1.1.1 Statistical Analysis of Differences in Historic and Current Survey Catch Rates

The catch rate for rainbow trout was different between the historic survey and current survey at the 80% confidence level (Table 2). Foothills Model Forest

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Table 2. Catch rate comparisons for the Lambert Creek watershed (Locations 926, 927, and 972).

Species ¹

Survey

ARGR

Historic Current Difference Historic Current Difference Historic Current Difference Historic Current Difference Historic Current Difference Historic Current Difference Historic Current Difference Historic Current Difference Historic Current Difference Historic Current Difference Historic Current Difference

BRST

BURB

FNDC

LNSC

NRPK

PRDC

RNTR

SPSC

TRPR

WHSC

Mean (# fish / Standard Deviation 100m² / min) (# fish / 100m² / min)

0.0000 0.0003 -0.0003 0.0000 0.0196 -0.0196 0.0017 0.0040 -0.0023 0.0000 0.0294 -0.0294 0.0087 0.0259 -0.0173 0.0005 0.0000 0.0005 0.0156 0.0000 0.0156 0.0029 0.0083 -0.0054 0.0000 0.0040 -0.0040 0.0020 0.0039 -0.0019 0.0489 0.0006 0.0484

0.0000 0.0005 0.0005 0.0000 0.0320 0.0320 0.0029 0.0037 0.0044 0.0000 0.0419 0.0419 0.0103 0.0307 0.0206 0.0009 0.0000 0.0009 0.0169 0.0000 0.0169 0.0039 0.0037 0.0019 0.0000 0.0049 0.0049 0.0035 0.0068 0.0033 0.0835 0.0006 0.0840

T-statistic

P-value

-1.000

0.423

-1.062

0.400

-0.901

0.463

-1.215

0.348

-1.450

0.284

1.000

0.423

1.601

0.251

-4.857

0.040*

-1.411

0.294

-1.000

0.423

0.998

0.423

* Significant difference at 80 % (α= 0.20) confidence interval. ¹ ARGR = Arctic Grayling; BRST = Brook Stickleback; BURB = Burbot; FNDC = Finescale Dace; LNSC = Longnose Sucker; NRPK = Northern Pike; PRDC = Pearl Dace; RNTR = Rainbow Trout; SPSC = Spoonhead Sculpin; TRPR = Trout-perch; WHSC = White Sucker

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

3.1.1.2 Changes in Proportion of Catchable Size Fish

At location 971, rainbow trout from both juvenile (< 120 mm) and adult (> 120 mm) sizes were present in 1979 and 2001 (Figure 2). Historic

Current

HISTORIC (1979) n = 17 Minimum FL = 51 Maximum FL = 148 Mean FL = 58

25

Number of fish

20

CURRENT SURVEY (2001) n = 83 Minimum FL = 50 Maximum FL = 210 Mean FL = 103

15

10

5

210

200

190

180

170

160

150

140

130

120

110

100

90

80

70

60

50

0

Fork Length (mm) Figure 2. A comparison of historic and current surveyed rainbow trout captured at Location 971 in the Lambert Creek watershed.

During the historic survey at Location 971, no rainbow trout with fork lengths greater than 149mm were captured (Table 3). However, during the current survey, 11 rainbow trout met this criterion. Table 3. Number of catchable size sport fish (>149mm) captured in the Lambert Creek watershed.

Location Species ยน

971

RNTR

Historic Total # # >149mm 17 0

Current Total # # >149mm 83 11

ยน RNTR = Rainbow Trout

The proportion of rainbow trout of catchable size at Location 971 was different between historic survey and current survey at the 80% confidence level (Table 4).

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Table 4. Proportion of catchable size sport fish (> 149mm) comparison for the Lambert Creek watershed.

Location 971

Species ¹ RNTR

Z-value -1.591

P-value 0.112*

* Significant difference at 80% (α = .20) confidence interval. ¹ RNTR = Rainbow Trout

3.1.2

MacKenzie Creek

3.1.2.1 Statistical Analysis of Differences in Historic and Current Survey Catch Rates

The catch rate for rainbow trout was different between the historic survey and the current survey at the 80% confidence level (Table 5). Table 5. Catch rate comparisons for the MacKenzie Creek watershed (Locations 432 and 961).

Species ¹

Survey

BLTR

Historic Current Difference Historic Current Difference Historic Current Difference

MNWH

RNTR

Mean (# fish / Standard Deviation 100m² / min) (# fish / 100m² / min)

0.0031 0.0026 0.0006 0.0000 0.0010 -0.0010 0.0713 0.0221 0.0492

0.0044 0.0036 0.0008 0.0000 0.0013 0.0013 0.0130 0.0047 0.0083

T-statistic

P-value

1.000

0.500

-1.000

0.500

8.339

0.076*

* Significant difference at 80% (α = .20) confidence interval. ¹ BLTR = Bull Trout; MNWH = Mountain Whitefish; RNTR = Rainbow Trout

3.1.2.2 Changes in Proportion of Catchable Size Fish

Although adult and juvenile size classes were present during both surveys at Location 962, juvenile size Rainbow Trout were poorly represented in the current survey sample (Figure 3).

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Historical

Current

HISTORIC (1983) n = 39 Minimum FL = 74 Maximum FL = 225 Mean FL = 130

9 8

CURRENT SURVEY (2001) n = 12 Minimum FL = 55 Maximum FL = 259 Mean FL = 163

Number of fish

7 6 5 4 3 2 1

260

250

240

230

220

210

200

190

180

170

160

150

140

130

120

110

100

90

80

70

60

50

0

Fork length (mm) Figure 3. A comparison of historic and current surveyed rainbow trout captured at Location 962 in the MacKenzie Creek watershed.

Most of the Rainbow Trout captured at Location 962 during the current survey were of catchable size (Table 6). Table 6. Number of catchable size sport fish (>149mm) captured in the MacKenzie Creek watershed.

Location Species ยน

962

RNTR

Historic Total # # >149mm 39 12

Current Total # # >149mm 12 9

ยน RNTR = Rainbow Trout

The proportion of rainbow trout of catchable size at locations 961 and 962 was different between the historic survey and the current survey (Table 7). Table 7. Proportion of catchable size sport fish (> 149mm) comparison for the MacKenzie Creek watershed.

Location 962

Species ยน RNTR

Z-value -2.722

P-value 0.007*

* Significant difference at 80% (ฮฑ = .20) confidence interval. ยน RNTR = Rainbow Trout

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

3.1.3

Moon Creek

3.1.3.1 Statistical Analysis of Differences in Historic and Current Survey Catch Rates

There were no differences in catch rates between the historic and current survey sites in Moon Creek at the 80% (α = .20) confidence interval (Table 8). Table 8. Catch rate comparisons for the Moon Creek watershed (Locations 8 and 19).

Species ¹

Survey

BLTR

Historic Current Difference Historic Current Difference Historic Current Difference

MNWH

RNTR

Mean (# fish / Standard Deviation T-statistic 100m² / min) (# fish / 100m² / min)

0.0556 0.0226 0.0330 0.0015 0.0006 0.0010 0.0192 0.0028 0.0164

0.0619 0.0255 0.0363 0.0021 0.0008 0.0013 0.0272 0.0040 0.0232

P-value

1.284

0.421

1.000

0.500

1.000

0.500

¹ BLTR = Bull Trout; MNWH = Mountain Whitefish; RNTR = Rainbow Trout

3.1.3.2 Changes in Proportion of Catchable Size Fish

Fork length data were not available from the historic survey at Location 19 in the Moon Creek watershed. 3.1.4

Pinto Creek

3.1.4.1 Statistical Analysis of Differences in Historic and Current Survey Catch Rates

There were no differences in catch rates between the historic survey and the current survey sites in Pinto Creek watershed at the 80% (α = .20) confidence interval (Table 9).

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Table 9. Catch rate comparisons for the Pinto Creek watershed (Locations 88 and 978).

Species ¹

Survey

Mean (# fish / 100m² / min)

ARGR

Historic Current Difference Historic Current Difference Historic Current Difference Historic Current Difference

0.0025 0.0026 -0.0001 0.0025 0.0000 0.0025 0.0085 0.0038 0.0047 0.0246 0.0650 -0.0404

BLTR

MNWH

RNTR

Standard Deviation T-statistic (# fish / 100m² / min)

0.0035 0.0036 0.0001 0.0035 0.0000 0.0035 0.0120 0.0054 0.0066 0.0107 0.0773 0.0880

P-value

-1.000

0.500

1.000

0.500

1.000

0.500

-0.648

0.634

¹ ARGR = Arctic Grayling; BLTR = Bull Trout; MNWH = Mountain Whitefish; RNTR = Rainbow Trout

3.1.4.2 Changes in Proportion of Catchable Size Fish

Fork length information was available from the historic surveys at both sites in Pinto Creek. However, the sample size was not greater than 10 for any fish species at any one site for the historic survey and current survey. Therefore, no additional analysis of fish size was presented. 3.1.5

Solomon Creek

3.1.5.1 Statistical Analysis of Differences in Historic and Current Survey Catch Rates

Due to a lack of historic effort data, neither a catch rate summary nor a statistical analysis for differences in catch rate could be completed. 3.1.5.2 Size Distribution

Brook trout were present in both juvenile and adult size classes at Location 131 in Solomon watershed (Figure 4).

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Historical

Current

HISTORIC (1992) n = 75 Minimum FL = 58 Maximum FL = 252 Mean FL = 105

18 16

Number of fish

14

CURRENT SURVEY (1997-99) n = 67 Minimum FL = 51 Maximum FL = 221 Mean FL = 117

12 10 8 6 4 2

260

250

240

230

220

210

200

190

180

170

160

150

140

130

120

110

100

90

80

70

60

50

0

Fork length (mm) Figure 4. A comparison of historic and current surveyed brook trout captured at Location 131 in the Solomon Creek watershed.

Brook Trout were the only fish species of catchable size (Table 10). Table 10. Number of catchable size sport fish (>149mm) captured in the Solomon Creek watershed.

Location Species ยน

131

BKTR

Historic Total # # >149mm 75 15

Current Total # # >149mm 67 19

ยน BKTR = Brook Trout

There was no difference in the proportion of catchable size Brook Trout at Location 131 in Solomon Creek at the 80% (ฮฑ = 0.20) confidence interval (Table 11). Table 11. Proportion of catchable size sport fish (> 149mm) comparison for the Solomon Creek watershed.

Location 131

Species BKTR

Z-value -1.165

P-value 0.244

ยน BKTR = Brook Trout

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

3.1.6

Upper Erith River

3.1.6.1 Statistical Analysis of Differences in Historic and Current Survey Catch Rates

Due to a lack of historic effort data, neither a catch rate summary nor a statistical analysis for differences in catch rate could be completed. 3.1.6.2 Changes in Proportion of Catchable Size Fish

At Location 714, juvenile and adult size classes of rainbow trout were present at both the historic survey and current survey (Figure 5). Historic

Current

HISTORIC (1979) N = 27 Minimum FL = 68 Maximum FL = 189 Mean FL = 116

4.5 4

Number of fish

3.5

CURRENT (1999) N = 19 Minimum FL = 78 Maximum FL = 199 Mean FL = 134

3 2.5 2

C

1.5 1 0.5

200

190

180

170

160

150

140

130

120

110

100

90

80

70

60

0

Fork length (mm) Figure 5. A comparison of historic and current surveyed rainbow trout captured at Location 714 in the Upper Erith River watershed.

Catchable size rainbow trout were present at both the historic survey and current survey (Table 12). Table 12. Number of catchable size sport fish (>149mm) captured in the Upper Erith River watershed.

Location Species ยน

714

RNTR

Historic Total # # >149mm 27 6

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Resurvey Total # # >149mm 19 6

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

There was no difference in the proportion of catchable size rainbow trout between the historic survey and current survey at location 714, at the 80 % confidence level (Table 13). Table 13. Proportion of catchable size sport fish (> 149mm) comparison for the Upper Erith River watershed.

Location 714

Species RNTR

Z-value -0.712

P-value 0.478

ยน RNTR = Rainbow Trout

3.2

Summary for all Monitoring Watersheds

3.2.1

Statistical Analysis of Differences in Historic and Current Survey Catch Rates

Statistical analysis of the differences in historic and current survey catch rates were performed in four of the watersheds using the catch rates from either two or three sample sites (Table 14). Differences in catch rates at the 80% confidence interval were found for rainbow trout abundance in the Lambert and MacKenzie Creeks. Differences were not significant for any of the other species found within these watersheds.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Table 14. Summary of statistical analysis of differences in historic and current survey catch rates.

Historic Catch Rates (# fish / 100m² / min) ARGR 0 BRST 0 BURB 0.0017 FNDC 0 LNSC 0.0087 Lambert 3 NRPK 0.0005 PRDC 0.0156 RNTR 0.0029 SPSC 0 TRPR 0.0020 0.0489 WHSC BLTR 0.0031 MacKenzie 3 MNWH 0 0.0713 RNTR BLTR 0.0556 Moon 2 MNWH 0.0015 RNTR 0.0192 ARGR 0.0025 BLTR 0.0025 Pinto 2 MNWH 0.0085 RNTR 0.0246 * Significant difference at 80% (α = .20) confidence interval. Watershed

Sample Species ¹ Size

Current Catch Rates (# fish / 100m² / min) 0.0003 0.0196 0.004 0.0294 0.0259 0 0 0.0083 0.004 0.0039 0.0006 0.0026 0.001 0.0221 0.0226 0.0006 0.0028 0.0026 0 0.0038 0.065

Difference P-Value

-0.0003 -0.0196 -0.0023 -0.0294 0.0206 0.0009 0.0169 0.0019 0.0049 0.0033 0.084 0.0006 -0.001 0.0492 0.033 0.0009 0.0164 -0.0001 0.0025 0.0047 -0.0404

0.423 0.4 0.463 0.348 0.284 0.423 0.251 0.040* 0.294 0.423 0.423 0.5 0.5 0.076* 0.421 0.5 0.5 0.5 0.5 0.5 0.634

¹ ARGR = Arctic Grayling; BLTR = Bull Trout; BRST = Brook Stickleback; BURB = Burbot; FNDC = Finescale Dace; LNSC = Longnose Sucker; MNWH = Mountain Whitefish; NRPK = Northern Pike; PRDC = Pearl Dace; RNTR = Rainbow Trout; SPSC = Spoonhead Sculpin; TRPR = Trout-perch; WHSC = White Sucker

3.2.2

Changes in Proportion of Catchable Size Fish

Statistical analysis of the differences in proportion of catchable size fish was completed within four of the monitoring watersheds (Table 15). Significant differences were found on two occasions. The increase in proportion of catchable size fish at the location in MacKenzie Creek corresponded to a poor representation of juvenile age classes.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

Table 15. Summary of Size Distribution for all selected monitoring watersheds.

Current survey Historic Watershed Species Site # Sample size P > 15cm Sample size P > 15cm P-Value Lambert RNTR 971 17 0 83 11 0.112* MacKenzie RNTR 962 39 12 12 9 0.007* Solomon BKTR 131 75 15 67 19 0.244 Erith RNTR 714 27 6 19 6 0.478 * Significant difference at 80% (ι = .20) confidence interval. š BKTR = Brook Trout; RNTR = Rainbow Trout

4

Discussion

4.1

Relationships Between Changes in Catch Rates, Angling Regulations and Land-use Changes in catch rates between historic and current surveys were detected in two of the

four watersheds where catch rate comparisons were completed (Table 16). In Lambert Creek watershed, an increase in catch rate corresponded to implementation of catch and release angling regulations. Harvest and road development levels were low during both historic and current surveys. In MacKenzie Creek watershed, a decrease in catch rate of Rainbow Trout corresponded to the implementation of zero catch limit of Bull Trout in 1995 and full angling closure in 2000. Harvest and road development levels remained low throughout the study. In Moon Creek watershed, no changes in catch rate were detected despite an implementation of more restrictive angling regulations. There was little change in harvest levels and there was a decrease in road density from high to medium. In the Pinto Creek watershed, no change in catch rate was detected despite an increase in angling restrictions, harvest extent and road development. To allow additional catch rate analyses, current surveys could be completed at two sites in both Anderson Creek watershed and Lynx Creek watershed, as well as one additional site in the Upper Erith River watershed. All of these watersheds have had some increase in either harvest level or road development.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

0 0

-

-

Lambert

4

4

0

Lynx

2

0

2

Future field inventory required Yes (+) RNTR Future field inventory required Yes (+) RNTR * low juvenile recruitment Insufficient sample size Insufficient sample size No

Yes (-) MacKenzie

4

3

1 RNTR

Moon

2

2

0

No

Pinto

4

2

2

No

Solomon

1

1

0

Insufficient historic data

Teepee Upper Erith River

0

-

-

2

1

1

Insufficient historic data

BKTR No RNTR

Implementation of catch and release restrictions Implementation of catch and release restrictions Implementation of catch and release restrictions • Zero Bull Trout limit introduced in 1995 • Full closure of stream to fishing in 2002 Implementation of catch and release restrictions Implementation of catch and release restrictions Implementation of catch and release restrictions Implementation of catch and release restrictions

¹ Harvest Information: < 10 % = low, 10-30 % = medium, > 30 % = high ² Index of Road Density: ≤ 0.2 = low, 0.3-0.4 = medium, ≥ 0.5 = high Foothills Model Forest

18

Change

Antler Fish

Future field inventory required Yes (+) RNTR Future field inventory required

Current

2

(yes / no)

Related angling regulation changes

Historic

0

(yes / no) ( +/- to indicate increase or decrease)

Index of Road Density ²

Harvest Information ¹

Change

# of potential sites lacking a current replicate

2

Significant change in proportion of catchable size fish

Current % Harvested

# of current replicate sites

Anderson

Watershed

Significant change in catch rate detected

Historic % Harvested

# of potential sites identified from historic reports

Table 16. Summary of changes in catch rates, fish size, angling regulations, harvest and road development in monitoring watersheds of the FMF.

med

high

med

high

high

low

-

-

-

-

-

-

low

low

low

low

low

low

low

med

low

low

high

med

low

low

low

low

low

low

med

med

low

high

med

low

low

med

med

low

med

med

low

low

low

low

low

low

-

-

-

-

-

-

low

low

low

low

high

high


Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

4.2

Relationships Between Changes in Proportion of Catchable Size Fish and Land-use Changes in proportion of catchable size fish were detected in two of the four watersheds

where those comparisons were completed (Table 16). In Lambert Creek watershed, an increase in proportion of catchable size fish corresponded to the implementation of catch and release angling regulations. Harvest and road development levels remained low through both survey dates. In MacKenzie Creek watershed, an increase in proportion of catchable size Rainbow Trout corresponded to very low juvenile recruitment and therefore should be considered an indicator of concern for the health of that population. This change corresponded to the implementation of more restrictive angling regulations including the zero catch limit on Bull Trout in 1995 and full angling closure in 2000. In Solomon Creek watershed, no significant changes in the proportion of catchable size Brook Trout were detected despite the more restrictive angling regulations and lack of increase in land-use. In the Upper Erith River watershed, no change in proportion of catchable size Rainbow Trout was detected despite the increase in angling restrictions and high increase in road development. To allow additional analyses of proportion of catchable size fish, the data from eight other historic sites could be reviewed to determine which sites would meet the sample size criteria for this test.

4.3

Considerations from Observed Relationships Via a major highway, Lambert Creek is in close proximity to the towns of Edson and

Robb. As a result, this watershed may have historically had the highest angling pressure of all the monitoring watersheds. Therefore, it seems plausible that the Rainbow Trout population in that watershed may have responded favourably to increased restrictions in angling regulations. In MacKenzie Creek, the decrease in Rainbow Trout catch rate is more difficult to explain. One possible explanation is the recent angling regulation changes. The province-wide ban on Bull Trout harvest may have resulted in an increase in Bull Trout use of MacKenzie Creek, which is an important Bull Trout spawning stream. Any increase in Bull Trout numbers may have resulted in increased Rainbow Trout predation in the MacKenzie Creek watershed. Investigating other potential factors seems warranted.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

4.3

Considerations for Future Foothills Model Forest Monitoring Efforts

4.4.1

Lack of Habitat Data

In order to practice adaptive forest management, any negative change in an aquatic resource would have to be linked to a particular forest management activity. For any changes other than those related to angling or angler access, some measure of habitat impact would be required. Most of the historic surveys did not contain habitat data that could have been replicated. In addition, specific hypotheses and methods related to habitat features should be formulated prior to initiation of future monitoring programs. Residual pool depths and spacing data have been collected at all sites and their potential as habitat indicators will be evaluated as part of this study. 4.4.2

Catch per Unit Effort Calculations from Backpack Electrofishing

Electrofishing effort was calculated based on area and time, however, power was not considered. Power is influenced by a number of factors including pulse width, pulse frequency, output voltage, water conductance, and anode size (Smith-Root Inc. 2002). Standardization of electrofisher power is a key component of maintaining consistent or comparable sampling effort (Smith-Root Inc. 2002). Standardization was not possible given the lack of information from most historical studies. In addition, recording water conductance has not been a standard requirement during Foothills Model Forest (FMF) electrofishing surveys. Therefore, changes should be made to FMF protocols to ensure that standardization of electrofishing power on any subsequent surveys can be achieved. 4.4.3

Fish Identification

During the historic surveys in Lambert Creek watershed, Pearl Dace were captured and no Finescale Dace was captured, while the reverse was true during the current surveys. These results indicate the possibility of a fish identification error. The current program could be expanded to include a more frequent use of voucher specimens or more rigorous testing of fish identification abilities. 4.4.4

Statistical Limitations

The use of catch rates as an indicator of fish population status presented several limitations including the very low sample size (n = 2 or 3) and high variability between sites in a

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

watershed. As a result, the possibility of both Type 1 and Type 2 error remained high. These problems were not associated with the use of proportion of catchable size fish. 4.4.5

Electrofishing and Fish Spawning Seasons

Damage to eggs within redds may occur as a result of electrofishing. Consequently, several jurisdictions require that electrofishing in known Bull Trout streams occurs prior to their spawning season. The FMF should consider adopting this practice.

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Report 1.2.1 - Changes Between Historic and Current Fish Relative Abundance and Size in Selected FMF Watersheds.

5

Literature Cited

Koning, C.W., and E.R. Keeley. 1997. Fish Habitat Rehabilitation Procedures in Watershed Restoration Technical Circular No.9. British Columbia Ministry of Environment, Lands and Parks and Ministry of Forests. Cao, Y.D.P. Larsen, and R.M. Hughes. 2001. Evaluating sampling sufficiency in fish assemblage surveys: a similarity-based approach. Canadian Journal of Fisheries and Aquatic Sciences. Vol. 58: 1782-1793. ESRI (Environmental Systems Research Institute). 2000. Arcview 3.2a GIS software. FMF (Foothills Model Forest). 2003. Report 1.2.2: Long-term changes in relative abundance of Rainbow Trout at selected sites within the Foothills Model Forest. Prepared for the ACA, Weldwood of Canada (Hinton Division) and ASRD. FMF, Hinton, Alberta. McCleary, R., C. Johnson, and C. Nelin. 2001. 2000 ACA Annual Report â&#x20AC;&#x201C; An evaluation of the effects of human-use on fish: A description of fish populations and habitats in selected watersheds within the Foothills Model Forest. Report completed for the Fisheries Management Enhancement Program, Alberta Conservation Association by the Foothills Model Forest. Moore, D.S. and G.P. McCabe. 1993. Introduction to the Practice of Statistics, second edition. W.H. Freeman and Company. New York. Smith-Root Inc. 2002. Principles and Techniques of Electrofishing. Vancouver, WA, USA. SPSS Inc. 1999. SPSS 10.0 for Windows software. Chicago, IL, USA.

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Fwp 2003 03 rpt changesbetweenhistoriccurrentfishrelativeabundancesize