Assessment of Sport Fish Distribution
and Relative Abundance in the Lower
Red Deer River, Alberta, Phase II
CONSERVATION
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Assessment of Sport Fish Distribution and Relative Abundance in the Lower Red Deer River, Alberta, Phase II Jason Blackburn and Jason Cooper Alberta Conservation Association 2nd Floor, YPM Place 530‐8 Street S. Lethbridge, Alberta T1J 2J8
Report Series Co‐editors PETER AKU KELLEY KISSNER Alberta Conservation Association 50 Tuscany Meadows Crescent NW #101, 9 Chippewa Rd Calgary, Alberta T3L 2T9 Sherwood Park AB T8A 6J7 Conservation Report Series Type Data, Technical ISBN printed: 978‐0‐7785‐7707‐2 ISBN online: 978‐0‐7785‐7708‐9 Publication No.: T/195 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: Blackburn, J., and J. Cooper. 2006. Assessment of sport fish distribution and relative abundance in the Lower Red Deer River, Alberta, Phase II. Technical report, T‐
2006‐003 produced by Alberta Conservation Association, Lethbridge, Alberta, Canada. 56 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) 410‐1998 Fax: (780) 464‐0990 Email: info@ab‐conservation.com Website: www.ab‐conservation.com i EXECUTIVE SUMMARY Fish species distribution and abundance was assessed on 450 km of the Lower Red Deer River (LRDR) using electrofishing. A total of 90 1‐km reaches were sampled of a predetermined 95 sample reaches. Species distribution and abundance, and total abundance by section, were determined from capture totals, visual counts, and catch‐
per‐unit‐effort (CPUE). Goldeye and shorthead redhorse displayed the broadest distributions, as well as the greatest abundance throughout the study area. Sauger was the next most abundant and widely distributed sport fish species, followed by walleye, burbot, mooneye, and northern pike. Sections with the highest total abundance of fish were section 1 near Joffre, downstream of the Highway 11 bridge crossing, and sections 12 to 13 near Buffalo and Bindloss, toward the confluence with the South Saskatchewan River near the Alberta ‐ Saskatchewan border. The total number of fish observed during sampling differed substantially from the total number captured, with 1,116 fish observed compared with only 429 captured. Capture success was low (inefficient) and possibly linked to water turbidity, with reduced success in clear water. Overall sample efficiency was highest via visual counts in clear water, with 58% of all tallied fish made by visual counts in three resampled sections. Comparison of abundance data collected in 2004 with that collected between 1990 ‐ 1991 revealed a statistically significant decline in total relative fish abundance from an average of 25.5 fish/km in 1990 – 1991 to 5.3 fish/km in 2004. In particular, significant decreases in abundance were observed for goldeye, sauger, walleye, white sucker, shorthead redhorse, longnose sucker, and quillback sucker. There was no significant change in relative abundance of burbot, mountain whitefish, northern pike, lake whitefish or lake sturgeon. Declines in abundance were attributed to sampling inefficiency in 2004 and/or the effects of consecutive drought years prior to the assessment. Species composition between assessments was similar; however, species distribution patterns were typically smaller and more fragmented in 2004. Species richness was greater in 2004 than the previous survey and was probably the result of a larger study area and greater sampling effort. In comparison to the assessment in 1990 ‐ 1991, aging structures collected in 2004 indicated slower growth rates in goldeye and mooneye, but faster rates for walleye and sauger. Use of a broader variety of sampling methods is recommended to increase capture success, and an angler creel survey could be used to verify anecdotal reports of increased sauger catches in recent years. A comprehensive habitat assessment of the ii LRDR should be conducted to assist future conservation measures to ensure sustainability of the fishery. Additional focused sampling of the data deficient species quillback and sauger should be undertaken, encompassing other southern Alberta river systems to ensure sufficient data capture. Long‐term monitoring of declining sauger and goldeye populations should also be initiated. iii ACKNOWLEDGMENTS This study was funded by the Alberta Conservation Association (ACA). Thanks to Kevin Wingert and Vance Buchwald (ASRD, Fish and Wildlife, Fisheries Biologists, Red Deer) and Cam Wallman (ASRD, Fish and Wildlife, Fisheries Biologist, Brooks) for their time and expertise piloting the boat and sampling during the field portion of the assessment. Special thanks to Byron Jensen (ASRD, Fish and Wildlife, District Conservation Officer, Drumheller) for offering his knowledge of the LRDR and for filling in and working long hours on the river on a Sunday when we were shorthanded. Additional thanks to Chad Tourand for providing accommodations and entertainment during equipment down‐time and repair. This report benefited from constructive comments offered by Cam Wallman, Glen Clements (ASRD, Fish and Wildlife, Fisheries Biologist, Lethbridge), Vance Buchwald and Trevor Council (ACA, Fisheries Biologist). iv TABLE OF CONTENTS EXECUTIVE SUMMARY...........................................................................................................ii
ACKNOWLEDGMENTS ..........................................................................................................iv
TABLE OF CONTENTS .............................................................................................................v
LIST OF FIGURES......................................................................................................................vi
LIST OF TABLES...................................................................................................................... vii
LIST OF APPENDICES .......................................................................................................... viii
1.0 INTRODUCTION ............................................................................................................ 1
1.1
Phase II objectives ........................................................................................................2
2.0 STUDY AREA................................................................................................................... 2
3.0. MATERIALS AND METHODS ..................................................................................... 5
3.1
Phase I ............................................................................................................................5
3.2
Phase II...........................................................................................................................7
4.0 RESULTS ......................................................................................................................... 11
4.1
Species composition and relative abundance.........................................................11
4.2
Species distributions ..................................................................................................15
4.3
Fish catchability ..........................................................................................................23
4.4
Sport fish species distribution and habitat observations......................................24
4.5
Non‐sport fish species distributions ........................................................................26
4.6
Comparison of 2004 and 1990 ‐ 1991 data...............................................................28
5.0 DISCUSSION .................................................................................................................. 40
5.1
Capture success in the 2004 assessment..................................................................40
5.2
Methodology...............................................................................................................41
5.3
Measuring total fish abundance and distribution .................................................43
5.4
Comparing relative abundances ..............................................................................44
5.5
Comparing species distributions .............................................................................48
5.6
Potential effects of angling ........................................................................................50
5.7
Future considerations and recommendations........................................................50
6.0 LITERATURE CITED .................................................................................................... 53
7.0 APPENDICES ................................................................................................................. 57
v
LIST OF FIGURES Figure 1.
Map of the Red Deer River watershed showing the 473 km study section ...4
Figure 2.
Catch‐per‐unit‐effort by species during the initial sampling event using electrofishing on the Lower Red Deer River in 2004. ......................................14
Figure 3.
Observed total number of fish by species from all sampling events on the Lower Red Deer River in 2004. ...........................................................................14
Figure 4.
Combined observed and captured fish totals by species from all sampling events on the Lower Red Deer River in 2004....................................................15
Figure 5.
Total catch‐per‐unit‐effort by river kilometer on the Lower Red Deer River in 2004. ...................................................................................................................21
Figure 6.
Combined observed and captured fish tallies per river kilometer during the initial spring sampling event on the Lower Red Deer River in 2004. ...........22
Figure 7.
Observed versus captured fish abundance per section on the Lower Red Deer River in 2004. ...............................................................................................22
Figure 8.
Comparison of combined observed and captured fish totals during initial spring conditions with observed totals from clear‐water resampling on the Lower Red Deer River in 2004. ...........................................................................23
Figure 9.
Comparison of capture results for sport fish species between assessments in 1990 – 1991 and 2004 on the Lower Red Deer River........................................29
Figure 10. Comparison of capture results of fish species between assessments in 1990 – 1991 and 2004 (initial sampling event) on the Lower Red Deer River..........29
Figure 11. Fish species presence by section in the Lower Red Deer River, 1990 ‐ 1991 and 2004. ................................................................................................................33
Figure 12. Combined observed and capture totals per sample kilometer, 1990 ‐ 1991 and 2004 .................................................................................................................34
Figure 13. Mean June discharge and percent fish recruitment from the 2004 total fish sample. ...................................................................................................................47
Figure 14. Mean June discharge and percent fish recruitment from the 1990 ‐ 1991 total fish sample.............................................................................................................48
vi LIST OF TABLES Table 1.
Fish species captured during the Lower Red Deer River sport fish assessment in 2004................................................................................................12
Table 2.
Summary of measurements and species abundance for fish species in the Lower Red Deer River assessment in 2004. ......................................................13
Table 3.
Species capture totals by section during the initial spring sampling event on the Lower Red Deer River in 2004. ....................................................................16
Table 4.
Observed species totals by section during the initial spring sampling event on the Lower Red Deer River in 2004. ...............................................................17
Table 5.
Combined captured and observed species totals by section for the initial spring sampling event on the Lower Red Deer River in 2004. ......................18
Table 6.
Combined captured and observed species totals during resampling of sections on the Lower Red Deer River in 2004. ................................................19
Table 7.
Combined captured, observed and catchability totals by species from all sampling events on the Lower Red Deer River in 2004. .................................20
Table 8.
Comparison of fish species totals and percent composition between assessments in 1990 – 1991 and 2004 on the Lower Red Deer River using data from sites common to both assessments...................................................30
Table 9.
A comparison of fish abundance between sites sampled in 1990 ‐ 1991 and 2004 assessments...................................................................................................31
Table 10.
Comparison of sport fish measurements between assessments in 1990 ‐ 1991 and 2004 on the Lower Red Deer River.............................................................37
Table 11.
Lower Red Deer River spring discharges at Red Deer during typical spring runoff months, and drought sequences preceding assessments in 1990 – 1991 and 2004. .......................................................................................................46
vii
LIST OF APPENDICES Appendix 1.
Location and site summary data for sampling sections on the Lower Red Deer River in 2004.. ............................................................................57
Appendix 2.
Lower Red Deer Phase II sample season windows...............................62
Appendix 3.
Lower Red Deer River turbidity and water quality data used to conduct Phase II of the study on the river in 2004. ...............................65
Appendix 4.
Comparison of species percent composition distributions by section between the 1990 ‐ 1991 assessment and initial sampling during the 2004 assessment on the Lower Red Deer River. ....................................70
Appendix 5.
Sauger age and length measurement relationships from the 1990 – 1991 and 2004 assessments on the Lower Red Deer River. ..................73
Appendix 6.
Walleye age and length measurement relationships from the 1990 – 1991 and 2004 assessments on the Lower Red Deer River. ..................77
Appendix 7.
Goldeye age and length measurement relationships from the 1990 – 1991 and 2004 assessments on the Lower Red Deer River. ..................81
Appendix 8.
Mooneye age and length measurement relationships from the 1990 – 1991 and 2004 assessments on the Lower Red Deer River. ..................85
Appendix 9.
Fork length frequency distributions for other species from the sport fish assessment on the Lower Red Deer River in 2004..........................89
viii
1.0 INTRODUCTION Effective management of sport fish populations depends, in part, on the availability of current information on their distribution and abundance. The Lower Red Deer River (LRDR) represents a 473 km river reach that supports a diverse assemblage of sport and non‐sport fish species. The status (distribution and abundance) of these species in the LRDR is poorly understood. Quantitative information on these species was most recently collected by Alberta Sustainable Resource Development (ASRD) in 1990 and 1991 (ASRD, Red Deer, File data). However, revisions of the provincial status of many Alberta fish populations suggest that population densities can change relatively rapidly. Consequently, up‐to‐date information on fish populations in the LRDR is required to support responsible and proactive management. The purpose of this study was to assess sport fish distribution and relative abundance in the LRDR to provide current and relevant information to assist with management of several sport fish populations including walleye (Sander vitreus), goldeye (Hiodon alosoides), mooneye (Hiodon tergisus), sauger (Sander canadense), and northern pike (Esox lucius). Of particular concern is sauger, which has been designated as a ‘Sensitive’ species (ASRD 2001); although, anecdotal evidence from angler reports suggests the population has been increasing over the last ten years in the LRDR. Quillback suckers (Carpiodes cyprinus) also occur in the LRDR and are also of special interest because the status of this species in the province is currently undetermined, and the species is considered ‘Data Deficient’ (ASRD 2001).
To undertake the assessment of the status of fish species in the LRDR, two separate phases of study were implemented. Phase I (the planning stage) was conducted in 2003 and included preliminary reconnaissance of the river to gather information on access, logistics, and to delineate study reaches within the study area (see Cooper and Council 2004). Phase II (the implementation stage) was undertaken in 2004, in cooperation with ASRD, to gather field data on distribution and abundance of sport and non‐sport fish along the 473 km stretch of the LRDR. Comparison of the results of this study (Phase II) to results from the earlier study on the LRDR in 1990 – 1991, and to results from other studies, will help illustrate long‐
1
term species population trends and will help assess the effectiveness of current sport fish regulations on the LRDR. 1.1 Phase II objectives The specific objectives of Phase II were to: i.
Collect fish species abundance and distribution data in the proposed study area for sport and non‐sport fish species; ii.
Analyze fish population and growth trends; iii.
Assess relative fish catchability via the selected sampling methodology; iv.
Compare species abundance, distribution, growth and population trends with previous assessments; v.
Prepare a Phase II final report; and vi.
Assess existing data deficiencies to direct future data collection priorities toward target species. 2.0 STUDY AREA The Red Deer River is one of four sub‐basins that constitutes the South Saskatchewan River Basin. The other three sub‐basins include the Bow, Oldman, and South Saskatchewan river basins. The Red Deer River is the largest of the sub‐basins with a watershed area of 46,998 km2, representing 41% of the South Saskatchewan River Basin area (Longmore and Stenton 1981). Although the largest, the Red Deer River sub‐basin contributes only 18% of the mean, annual, natural flow of the South Saskatchewan River Basin, with the Bow, Oldman, and South Saskatchewan sub‐basins contributing 43%, 38% and 0.7%, respectively (Golder 2003). 2 The Red Deer River originates in the Rocky Mountains, roughly 30 km within the eastern boundary of Banff National Park, northeast of Lake Louise, Alberta (Figure 1). The river begins a 708‐km traverse eastward through the foothills boreal forest to Sundre (Roth 2002). The river then flows northeast into the Parkland region, and is backed up by the only impoundment on the river, the Dickson Dam, which forms Gleniffer Reservoir. The river continues northeast through Red Deer and then south. A transition from Parkland to the Badlands region begins as the river nears Drumheller where it continues southeast toward Dinosaur Provincial Park. Finally, from the park onward, the river meanders easterly through the rolling grasslands across the Alberta ‐ Saskatchewan provincial boundary (Swenson 2002), where it flows an additional 17 km in Saskatchewan before reaching the confluence with the South Saskatchewan River. The Red Deer River is unique to Alberta in that it flows through all five of Alberta’s major ecoregions: mountain, foothills, boreal forest, parkland and prairie (Rood et al. 2002). The lower two‐thirds of the Red Deer River from Joffre (Highway 11 bridge crossing) to the Alberta ‐ Saskatchewan border is 473 km long and represents about 67% of the entire watercourse. This section of river consists of a large, single, wide channel (89 m at Red Deer, 96 m at Drumheller, 168 m at Empress), with a mean depth ranging from 0.8 ‐ 1.0 m, interspersed with islands and sand bars. This particular stretch of river has a very flat gradient (0.8 ‐ 0.3 m/km) and high turbidity levels downstream of Drumheller. The upper part of this section of river from Joffre to Drumheller generally consists of clearer water, with gravel streambeds in riffle areas, and long stretches of fine sand/silt substrate in pool and run areas. The lower part of the Red Deer River from Drumheller to the Alberta ‐ Saskatchewan border has a predominant sand/silt streambed and experiences a constant high level of turbidity (Longmore and Stenton 1981). These features contribute to a river that is relatively warm and slow moving. Cool water sport species are known to inhabit the lower two‐thirds of the Red Deer River, as well as warm water non‐sport species. Low discharge rates, low dissolved oxygen levels, high turbidity and high summer water temperatures are believed to be why fish populations and production in this stretch of river are limited and species abundance is low. 3 10
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Map of the Red Deer River watershed showing the 473 km study section (map from Longmore and Stenton 1981). 3.0. MATERIALS AND METHODS 3.1 Phase I 3.1.1 Review of the 1990 ‐ 1991 study Phase I began with an information session with the ASRD Area Fisheries Biologist in Red Deer, Vance Buchwald, on how the previous assessment of the LRDR in 1990 – 1991 was conducted, including sampling methodology, location of sampling sites, time of year of sampling, and a brief summary of capture results from 1990 ‐ 1991. Topographical maps with 1990 ‐ 1991 sample locations were obtained and the locations were converted into Universal Transverse Mercator (UTM) coordinates (NAD 83) using ASRD’s Spatial Data Management Environment (SDME) Internet Mapping Framework (IMF) (Appendix 1). UTM coordinates were then put in a Global Positioning System (GPS) unit. 3.1.2 Ground reconnaissance Reconnaissance was conducted on the ground in June 2003 to locate suitable launching sites for an electrofishing jet boat, with water levels in mind. Photos were taken and field forms developed. Logistic information was collected and included the location of nearest fuel facilities, campsites and accommodations, and supply facilities (to aid in partitioning the river into manageable daily sample sections). Information regarding sandbar locations and potential low‐water obstructions was also collected. 3.1.3 Water flow review Historical water flow data were compiled from Alberta Environment in an attempt to establish a sample window with sufficient flows to safely maneuver a jet boat, but with low enough discharge to effectively capture fish. Extensive historical review of spring discharge and consultation with Vance Buchwald (ASRD, Red Deer) and Conservation Officer Byron Jensen (ASRD, Drumheller), dictated that a reactionary approach to daily river conditions was imperative in order to complete Phase II of the project. 5 3.1.4 Known fish species composition A summary of fish species known to be present in the LRDR was compiled from previous assessments and literature. Lists of known sport fish and non‐sport fish species were produced to help predict the fish community that would likely be encountered, and to generate a suitable field fish‐identification key. The list of sport fish included: northern pike, sauger, mooneye, lake whitefish (Coregonus clupeaformis), yellow perch (Perca flavescens), burbot (Lota lota), lake sturgeon (Acipenser fulvescens), mountain whitefish (Prosopium williamsoni) and goldeye. Goldeye were expected to be the most numerous sport fish species present in this lower stretch of river (Longmore and Stenton 1981; B. Jensen, pers. comm.). Only a slight chance of encountering rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) was expected, and only in the uppermost part of the study section (Joffre area). The non‐sport fish species list included: emerald shiner (Notropis atherinoides), river shiner (Notropis blennius), spottail shiner (Notropis hudsonius), flathead chub (Platygobio gracilis), longnose dace (Rhinichthys cataractae), quillback sucker, longnose sucker (Catostomus catostomus), white sucker (Catostomus commersoni), shorthead redhorse (Moxostoma macrolepidotum), silver redhorse (Moxostoma anisurum), trout‐perch (Percopsis omiscomaycus), and spoonhead sculpin (Cottus ricei) (RL & L 1997). Other non‐sport fish species expected to be present in the LRDR according to Nelson and Paetz (1992) were: lake chub (Couesius plumbeus), pearl dace (Margariscus margarita), northern redbelly dace (Phoxinus eos), finescale dace (Phoxinus neogaeus), fathead minnow (Pimephales promelas) and brook stickleback (Culaea inconstans). 3.1.5 River section division The study area is 473 km in length from the Highway 11 bridge crossing east of Red Deer to the Alberta ‐ Saskatchewan provincial boundary. Partitioning of the river into manageable, logistically feasible reaches was essential for the completion of the assessment. Based on ground assessments, personal communications, ortho‐photo interpretation, and launch / crossing locations, the 473 km reach of the LRDR was divided into 13 sections ranging from 26 to 49 km in length with between five to ten sample locations (reaches) per section (Appendix 1; also see Cooper and Council 2004). This division resulted in a total of 95 1‐km reaches along the river being identified for 6 sampling (Cooper and Council 2004). Of these, 80 reaches corresponded (as closely as possible) to sites sampled during the 1990 – 1991 study (see section 3.1.1). Details on these sites and the additional sample reaches not sampled during the 1990 ‐ 1991 survey are provided in Cooper and Council (2004). 3.1.6 Angling and fisheries management Based on the information collected during Phase I, it was concluded that angling pressure is considered light with very few anglers fishing by boat (B. Jensen, pers. comm.), and that pressure is typically heavy only at access points (bridges) where most anglers target goldeye, walleye, and sauger (Longmore and Stenton 1981). However, there has never been a comprehensive angler survey conducted on the LRDR. 3.2 Phase II 3.2.1 2004 water flow The minimum discharge required to safely jet boat the river was 50 m3/s at the Red Deer gauging station (Vance Buchwald, ASRD, pers. comm.). As a result, flows and river levels were scrupulously monitored on the Alberta Environment website (Alberta Environment 2004) throughout the spring, leading up to and well into the recommended sampling window of late May through early July (Cooper and Council 2004). When flows reached acceptable sustained levels, sampling commenced. Additional resampling of sites was conducted after the recommended timeframe had passed because flows remained suitable longer than expected (Appendix 2). 3.2.2 Sampling methodology Jet boat electrofishing was used to capture fish. A Coffelt VVP 15 electrofisher and dual six‐dropper anode arrays on booms were used on a fiberglass Glascon river jet boat propelled by a 90 hp Evenrude outboard jet. As above, 80 sample sites from the fisheries inventory done in 1990 ‐ 1991 were sampled in 2004 and were located using a Garmen Etrex GPS unit uploaded with UTM coordinates using Garmin MapSource Metro Guide Canada V4 Software. Electrofishing was conducted in a downstream progression starting at section 1 downstream of the Highway 11 bridge crossing and 7 ending at section 13 near the Bindloss bridge crossing. Sample locations were 1 km in length and occurred systematically every 5 km, representing a variety of riverine habitats (riffle, pool, run) through random chance (Cooper and Council 2004). Upon arrival at a sample location, the boat was slowed to a drift and electricity was administered 10 s on and 8 s off, plus whatever additional output was deemed necessary to contain fish in the electrical field. Typically, electrofishing was conducted along the banks and in areas of cover; however, open water sections in the main channel were also sampled when habitat was homogenous. Measurements were recorded of electrofishing output in voltage and amperage, and effort in seconds. Captured fish were contained in a live‐well until the end of each respective 1‐km sample stretch at which point fish were sampled and released back to the river. Fish data collection included species, condition, fork‐length (FL), weight, sex when possible, and non‐lethal aging structures. Capture locations were also recorded to verify species distributions throughout the watercourse. All species of sport fish greater than 250 mm FL were tagged with Hallprint® T‐bar anchor fish tags. Tags were orange in color and were imprinted with a unique sequential identification number beginning at SER 12000 and a phone number to facilitate voluntary reporting of recaptures by anglers. Occasional repeat sampling of sites was conducted in an attempt to establish fish catchability on given sampling events. Marked fish were released back to the section of stream in which they were initially captured and ratios of marked to unmarked fish captured on repeat runs were recorded. Throughout the course of electrofishing, many fish were observed but evaded capture. Consequently, a running tally of observed numbers of each species was initiated to account for readily identifiable fish that avoided capture. Some sections that were thought ineffectively sampled during initial spring sampling were subsequently resampled at a later date to validate first pass assessment results. Water conditions were recorded at intervals throughout the assessment. Water clarity was measured as the depth‐of‐visibility; the approximate measure of underwater distance (depth) that crewmembers can accurately identify subsurface features and fauna. Additional water quality measurements included water temperature and conductivity (Appendix 3). 8 3.2.3 Species distribution and abundance analysis All fish and site data were compiled into a Microsoft Access database and also housed in the provincial government’s Fisheries Management Information System (FMIS) database. Species composition and distribution were determined from all fish tallied during initial spring sampling, summer resampling, and all catchability runs combined. Species distributions were determined based on presence/absence per river section on a per‐species basis, to assess continuity of distributions in the study area. Species presence by section was determined using only initial spring sampling. Species presence/absence was compared with 1990 ‐ 1991 results to examine possible changes in species distribution patterns and range. Proportionate species distribution by section was compared between 2004 and 1990 ‐ 1991 assessments for four sport fish species and one non‐sport fish species to compare the percent composition of the species totals in relation to their locations in the study area. Species abundance per section was measured in terms of catch‐per‐unit‐effort (CPUE), observed fish totals, captured fish totals, and combined totals (observed and captured) per section. CPUE was calculated for all captured fish during initial spring sampling based on electrofishing effort. Total fish abundance on a per section and per sampled river kilometer basis was evaluated in an attempt to illustrate general fish productivity levels throughout the watercourse. Combined observed and captured totals per section were compared between 2004 and 1990 ‐ 1991 assessments to illustrate trends in total fish productivity by location along the watercourse and change over time. Relative species abundance was measured in CPUE of boat electrofishing time as well as combined observed and captured fish totals. Comparisons of relative abundance between 2004 data and data from 1990 – 1991 were made using data from 80 sample locations that were similar between studies for total combined fish species, as well as per species. Paired t‐tests were used to compare results from the two assessments using JMP IN Statistical Discovery Software, version 4.0. 3.2.4 Capture and biological data analysis Biological data collected on all fish successfully captured and measured was used to assess catchability and investigate population structure and growth. 9 To assess catchability of fish, sites where all fish captured on the previous sampling event were marked were resampled. The subsequent ratio of marked to unmarked fish was intended to provide a ratio of the proportion of fish captured during a given sampling event, and thus reflect the ability to estimate total fish present per sampling location. Length data for captured samples of fish species were compiled into fork length frequency distributions to assess size class distribution trends per species and were compared with 1990 ‐ 1991 data. Length‐at‐age and age‐class profiles were produced for sport fish species with suitable non‐lethal aging structures and sufficient sample sizes. The profiles were compared with previous studies and/or other provincial rivers. Growth was assessed using von Bertalanffy growth equations (von Bertalanffy 1938) and growth equations were calculated using Fisheries Analysis and Simulation Tools (FAST) version 2.0 software. The von Bertalanffy (1938) growth equation is: L t = L ∞ (1 ‐ e
‐k (t ‐ t 0 )
)
where, Lt = length at age t, L∞ = the asymptote or final maximum size, K = the rate at which the growth curve approaches the asymptote, and t0 = a time scaler, the hypothetical time when the fish was size zero. The parameter used to estimate growth in the von Bertalanffy model is K, which represents the rate at which the fish approaches maximum size (L∞). Higher values of K represent faster growth and are usually associated with a lower L∞. Due to small sample sizes of small fish, t0 was fixed at zero to reduce bias in the growth function. 10 4.0 RESULTS Spring sampling commenced on 15 June at section 1 near Joffre and concluded on 29 June at section 13 near Bindloss. A total of 90 1‐km reaches were sampled of the proposed 95 sample reaches (Appendix 1). Mechanical failure ended the survey 20 km short of the 470 km target objective; however an additional ten sample reaches were added to the 1990 ‐ 1991 survey area, representing an additional 45 km of river sampled in 2004. A total of 19 1‐km reaches were resampled on 28 ‐ 29 July from section 3 at km 385 to the first site in section 6 at km 294. 4.1 Species composition and relative abundance Nine of 12 potential sport fish species known to be present in the LRDR were captured in 2004 (Table 1). Yellow perch, rainbow trout, and brown trout were not captured or observed during sampling. Nine non‐sport fish species were captured in the LRDR in 2004. Of non‐sport fish previously captured in the LRDR (RL&L 1997), silver redhorse, spottail shiner, trout‐perch and spoonhead sculpin were absent from 2004 samples. Lake chub was not captured in the earlier study, but was captured in 2004. In total, 429 fish were captured through electrofishing. An additional 1,116 fish were observed (visually) but were not captured (Table 2 and Figures 2 and 3). Goldeye was the most abundant species in the study comprising the highest total CPUE via electrofishing with 1.48 fish/10 min captured during spring sampling. A total of 173 goldeye were captured and an additional 498 fish were observed (Table 2 and Figures 2 to 4). Important to note, when tallying observed fish, goldeye and mooneye were both considered goldeye due to the inability to distinguish them during visual counts. Sauger was the second‐most abundant species in terms of CPUE (0.51 fish/10 min; Figure 2). However, in terms of total abundance, shorthead redhorse was the second‐
most abundant species with a combined observed and captured total of 322 fish, followed by 180 white suckers and 132 sauger (Figure 4). Overall, goldeye comprised 43% of the total sample (i.e., captured and observed fish) followed by shorthead redhorse (21%), white sucker (12%) and sauger (9%). Walleye 11 comprised 4% of the total, while northern pike, mooneye and burbot each contributed 2%. Together, quillback sucker, longnose sucker, lake sturgeon, mountain whitefish and lake whitefish comprised the remaining 5% of the sample. Table 1. Fish species captured during the Lower Red Deer River sport fish assessment in 2004. Family Common name Scientific name Code* Sport fish Acipenseridae Esocidae Gadidae Hiodontidae Percidae Salmonidae Lake Sturgeon Northern Pike Burbot Goldeye Mooneye Sauger Walleye Mountain Whitefish Lake Whitefish Acipenser fulvescens Esox lucius Lota lota Hiodon alosoides Hiodon tergisus Sander canadense Sander vitreus Prosopium williamsoni Coregonus clupeaformis LKST NRPK BURB GOLD MOON SAUG WALL MNWH LKWH Non‐sport fish Catostomidae White Sucker Catostomus commersoni Longnose Sucker Catostomus catostomus Shorthead Redhorse Moxostoma macrolepidotum Quillback sucker Carpiodes cyprinus Cyprinidae Lake Chub Couesius plumbeus Flathead Chub Platygobio gracilis Emerald Shiner Notropis atherinoides River Shiner Notropis hudsonius Longnose Dace Rhinichths cataractae *Fish species codes follow MacKay et al. (1990). WHSC LNSC SHRD QUIL LKCH FLCH EMSH RVSH LNDC Summer resampling of three sections resulted in a total of 906 individuals, of which 98% were observed and 2% were captured. Totals from the resampled sections represented 59% of the total fish tallied in 2004. Goldeye was again the most abundant species comprising 44% of the sample, shorthead redhorse 27%, white sucker 17%, walleye 4%, sauger 4%, northern pike 2%, quillback sucker 1%, and burbot and longnose sucker together the remaining 1%. 12 Table 2. Summary of measurements and species abundance for fish species in the Lower Red Deer River assessment in 2004. Catch‐per‐unit‐effort (CPUE) is based on initial spring sampling conducted between 18 – 29 June, and excludes resampling events between 28 ‐ 29 July. Species GOLD MOON SAUG NRPK WALL LKWH MNWH BURB LKST SHRD QUSC WHSC LNSC FLCH TOTAL Total measured CPUE (# fish/10 min) Total observed 173 31 62 8 16 6 9 27 1 35 2 17 10 32 429 1.57 0.28 0.55 0.07 0.15 0.05 0.08 0.25 0.01 0.33 0.02 0.08 0.09 NA 3.61 498 3 70 24 41 0 0 11 2 287 16 163 1 NA 1,116 Fork length (mm) Max 401 296 489 962 708 448 379 719 1,005 450 412 481 456 230 13 Min 207 244 189 404 143 346 156 236 1,005 155 407 170 201 104 Mean 320 268 359 643 449 370 215 355 1,005 344 410 387 399 163.4 Weight (g) S.D. 26 12 60 172 179 39 78 100 N/A 82 4 101 75 28.2 Max 730 296 1,210 3,585 4,230 1,145 845 1,640 N/A 1,485 1,410 1,930 1,370 145 Min 195 244 50 430 25 470 40 95 N/A 50 1,265 80 105 5 Mean 366 268 458 1,760 1,411 673 184 321 N/A 344 1,338 1,059 903 51.4 S.D. 97 14 234 1,981 1,363 243 266 311 N/A 344 102 524 355 33.1 Total effort = 18.33 hours
2.0
N = 163
1.5
1.0
N = 56
0.5
N = 31
N = 24 N = 24
N = 17
N = 14
N= 9
N= 8
N= 7
0.0
N= 6
N= 1
N= 1
GOLD SAUG MOON SHRD BURB WHSC WALL LNSC MNWH NRPK LKWH QUIL LKST
Figure 2. Catch‐per‐unit‐effort (CPUE) by species during the initial sampling event using electrofishing on the Lower Red Deer River in 2004. 800
N = 1116
700
600
N = 501
500
400
N = 287
300
200
N = 163
N = 70
100
N = 41
N = 11
N = 24
N = 16
N=1
N=2
BURB
NRPK
QUIL
LNSC
LKST
0
GOLD &
MOON
Figure 3. SHRD
WHSC
SAUG
WALL
Observed total number of fish by species from all sampling events on the Lower Red Deer River in 2004. 14 800
N = 1544
N = 705
700
600
500
400
N = 321
300
N = 180
200
N = 132
100
N = 57
N = 38
N = 32
N = 18
N = 11
N=9
N=3
BURB
NRPK
QUIL
LNSC
MNWH
LKST
0
GOLD&
MOON
Figure 4. SHRD
WHSC
SAUG
WALL
Combined observed and captured fish totals by species from all sampling events on the Lower Red Deer River in 2004. 4.2 Species distributions General distributions (based on species presence) varied between species as the fish community changed with habitat. With the exception of shorthead redhorse and goldeye, which were consistently present throughout the entire study area, there was a general decline in species richness downstream. This was particularly evident in sections 8 and 9 from the Finnegan Ferry crossing to Dinosaur Provincial Park where there was very low species diversity and abundance. Species diversity and abundance appeared to increase with proximity to the confluence with the South Saskatchewan River (Tables 3 to 7). 15 Table 3. Species capture totals by section during the initial spring sampling event on the Lower Red Deer River in 2004. BURB FLCH GOLD LKST LKWH LNSC MNWH MOON NRPK QUIL SAUG SHRD WALL WHSC 1 16 16 6 7 5 19 6 13 6 9 14 2 4 16 3 7 7 1 3 2 4 2 4 1 5 1 1 5 2 1 SECTION 6 7 8 1 3 6 1 36 7 8 1 3 1 3 4 3 1 1 TOTAL 117 38 8 1 10 51 SPECIES 15 *Only two sites were sampled in section 13. 16 13 9 9 1 1 10 4 20 1 9 1 1 1 11 1 7 23 6 1 12 1 1 18 1 1 6 3 1 13* 7 3 1 2 5 2 11 37 38 32 20 TOTAL 24 30 163 1 6 9 8 31 7 1 56 24 14 17 391 Table 4. Observed species totals by section during the initial spring sampling event on the Lower Red Deer River in 2004. BURB FLCH GOLD LKST LKWH LNSC MNWH MOON NRPK QUIL SAUG SHRD WALL WHSC 1** 2** 3 2 1 1 1 4 1 2 1 1 4 4 5 3 SECTION 6 7 8 1 1 14 4 12 1 1 3 3 2 6 1 1 4 TOTAL 0 0 5 13 3 24 SPECIES 8 22 9 7 10 11 1 5 6 11 22 1 1 13 8 5 12 1 30 2 5 8 1 13* 8 3 6 1 7 23 50 47 18 *Only two sites were sampled in section 13. **Observed totals in sections 1 and 2 were influenced by high turbidity levels. 17 TOTAL 3 0 109 2 0 0 0 3 10 3 39 39 7 5 220 Table 5. Combined captured and observed species totals by section for the initial spring sampling event on the Lower Red Deer River in 2004. BURB FLCH GOLD LKST LKWH LNSC MNWH MOON NRPK QUIL SAUG SHRD WALL WHSC 1 16 16 6 7 5 19 6 13 6 9 14 2 4 16 3 7 7 1 3 2 2 5 3 1 4 1 3 1 1 4 4 5 1 1 5 3 2 1 SECTION 6 7 8 1 2 3 6 1 50 11 20 2 4 4 6 2 10 4 2 4 1 TOTAL 117 38 13 14 13 75 SPECIES 23 *Only two sites were sampled in section 13. 18 35 9 16 1 1 10 4 31 1 1 14 7 1 1 11 1 7 45 1 1 19 8 6 12 2 1 48 1 3 11 11 2 13* 7 11 1 5 11 3 18 60 88 79 38 TOTAL 27 30 272 3 6 9 8 34 17 4 95 63 21 22 611 Table 6. Combined captured and observed species totals during resampling of sections on the Lower Red Deer River in 2004. SPECIES BURB FLCH GOLD LKST LKWH LNSC MNWH MOON NRPK QUIL SAUG SHRD WALL WHSC TOTAL SECTION 3 4 5 3 1 5 130 137 128 1 3 8 1 9 2 8 22 39 76 124 4 16 14 10 31 97 188 273 408 6* 4 3 3 7 20 37 TOTAL 9 0 395 0 0 1 0 0 15 13 35 246 34 158 906 *Only one sample site was resampled in section 6. 19 Table 7. Combined captured, observed and catchability totals by species from all sampling events on the Lower Red Deer River in 2004. SPECIES SECTION 6* 7 8 1 2 3 6 1 50 11 20 2 4 8 3 9 2 10 11 2 4 21 BURB FLCH GOLD LKST LKWH LNSC MNWH MOON NRPK QUIL SAUG SHRD WALL WHSC 1 16 16 6 7 5 19 6 13 7 9 14 2 5 18 1 4 7 7 3 3* 4* 5* 3 1 6 1 132 138 133 1 3 2 4 11 1 9 7 9 24 41 80 125 4 16 14 11 35 97 TOTAL 118 45 200 287 421 112 23 * Denotes sample sections that were resampled (shaded). **Only two sites were sampled in section 13. 20 35 9 16 1 1 10 4 31 1 1 14 7 1 1 11 1 7 45 1 1 19 8 6 12 2 1 54 1 3 14 17 2 13* 1 9 7 1 1 4 15 5 18 60 88 94 43 TOTAL 38 32 671 3 6 11 9 34 32 18 132 321 57 180 1,544 4.2.1 Total fish productivity by section Section 1 had the highest average CPUE per section with a mean of 11.5 fish/10 min of electrofishing and the highest maximum CPUE at any sample site in the study at 18.7 fish/10 min (Figure 5; Appendix 1). Sections with the next highest average CPUE values were section 13 with a mean of 7.18 fish/10 min and section 6 with a mean of 4.24 fish/10 min. Figure 5. Total catch‐per‐unit‐effort (CPUE) by river kilometer on the Lower Red Deer River in 2004. After section 1, sections 6, and 11 through 12 were the next most productive sections in terms of total fish numbers with combined observed and captured fish totals of 75, 88 and 79 individuals, respectively (Table 5 and Figure 6). A comparison of captured versus observed fish totals showed similar river transects where peak numbers occurred, specifically sites in section 6 and sections 10 though 12 (Figure 7). However, in sections 1 and 2, fish were exclusively captured and not observed, and in section 4 fish were almost exclusively observed and not captured. Generally, there was a trend for totals of captured fish to be highly variable across study sections; whereas there was a general increasing trend in total numbers of observed fish (Figure 7). 21 Figure 6. Combined observed and captured fish tallies per river kilometer during the initial spring sampling event on the Lower Red Deer River in 2004. Figure 7. Observed versus captured fish abundance per section on the Lower Red Deer River in 2004. 22 Clear‐water resampling of the least productive sections from the early sampling period (sections 3 through 5 and one site in section 6) resulted in observed totals a full order of magnitude higher than the total number of fish enumerated in the same sections during initial sampling (Figure 8). Total fish caught and observed per site averaged only 1.2 fish during initial sampling but increased significantly to 47.7 fish/site during clear water resampling (P = < 0.0001, df = 18). Figure 8. Comparison of combined observed and captured fish totals during initial spring conditions with observed totals from clear‐water resampling on the Lower Red Deer River in 2004. 4.3 Fish catchability During the 2004 assessment a total of four catchability runs were conducted with only two recaptures. Initial capture success was low because of avoidance, resulting in a corresponding low recapture success. Consequently, no meaningful ratio could be calculated. Evidence from observed totals (compared to total fish captured) and fish behavior (observed avoidance) suggested that only a small fraction of fish present within an area were successfully captured. 23 4.4 Sport fish species distribution and habitat observations 4.4.1 Goldeye Goldeye showed the greatest abundance and the most continuous distribution throughout the 2004 assessment (Tables 3 and 5). This species was frequently observed in large roaming schools, particularly during summer resampling when the water was extremely clear. Schools were tight and typically comprised of approximately 30 individuals, although schools as large as 60 individuals were observed. Fish were captured in a variety of habitats including deep pools, shallow riffles, inside and outside bends, near structure, and in flat open‐water with no apparent cover. 4.4.2 Mooneye Mooneye was present sporadically through the sample area. Mooneye was observed more frequently in upper reaches and was less prevalent in middle and lower reaches (Table 5). Mooneye was found in habitats similar to that of goldeye. Although mooneye may have been counted as goldeye during visual counts, capture rates suggest mooneye occur only in small numbers (Table 3). 4.4.3 Sauger Sauger was consistently represented through most of the sample sections with the exception of middle stretches (sections 7 ‐ 9) where all species were low in abundance (Table 5 and Figure 5). Sauger tended to occur in shallow water, which probably contributed to its relatively high CPUE due to the close proximity of the electrical field. Fish were frequently found in shallow fast moving riffle‐crest areas at tail‐outs of pools or runs and also in deeper pools and holding close to shoreline structure. Juvenile sauger were captured along with juvenile walleye in a shallow muddy rearing area vegetated by sparse rushes and flooded willows, near the Bindloss bridge crossing in section 12. 24 4.4.4 Northern pike Northern pike was observed periodically, but in low numbers primarily upstream of Bindloss (Table 5). Pike occurred exclusively in locations of high vegetative cover, typically slow moving pools, and deeper runs or eddies with abundant aquatic vegetation or woody debris. Downstream of section 6 (Drumheller), the species was less abundant as the river channel became more broad and open. 4.4.5 Whitefish Both lake whitefish and mountain whitefish were captured in small numbers in only the uppermost portions of the study area (Tables 3 and 5). Whitefish were captured concurrently with goldeye in a variety of habitats. Distribution of whitefish is likely limited by temperature tolerances, as downstream maximum summer temperatures exceed whitefish tolerance limits (Longmore and Stenton 1981). 4.4.6 Walleye Walleye was present in moderate abundance in the upper and lower portions of the study area. Walleye occurred sparsely in sections 2 through 9 (Table 5). Fish were located primarily in deep pools and occasionally in faster moving runs. Walleye capture success was likely poor because of its deep‐water habitat preference, positioning it beyond the reach of the electrical field. Large walleye were observed at the bottom of deep pools and were not affected by the electrical field. Walleye were also observed lying in direct contact with the river bottom, which is common for sauger but not typically of walleye (Nelson and Paetz 1992). 25 4.4.7 Lake sturgeon Lake sturgeon was first observed and recorded in section 6 while traveling between sample sites. This individual was identified during an acrobatic leap directly in line with the boat’s trajectory of travel. The first and only lake sturgeon captured was also in section 6 near the hamlet of Dorothy. An additional sturgeon was observed near Jenner in section 11 where large, deep pools were documented. 4.4.8 Burbot Burbot was continuously distributed throughout most of the study area in small numbers (Table 5). Fish were observed where large substrate, vegetation, or cover persisted, and were also observed in the broad, open channel portion of the river. 4.5 Non‐sport fish species distributions 4.5.1 Shorthead redhorse Shorthead redhorse was the most abundant and most widely distributed of the four sucker species captured during the survey (Table 5), and had the second‐largest numbers of any species throughout the study area. Shorthead redhorse were observed in slow‐moving, shallow stretches with all kinds of substrates including rocky, vegetated or clay/sand bottoms. During the summer resampling, large schools of 25 ‐ 50 individuals were observed. 4.5.2 White sucker White sucker was found mainly in the upper portion of the study area but was also represented in lower reaches (Table 5). Large white suckers were captured individually in slow‐moving eddies and pools and in areas of cover. Smaller white suckers were typically found in large schools, with as many as 45 individuals (Table 6), over a variety of substrates including rocky, silty and vegetated bottoms. 26 4.5.3 Longnose sucker Longnose sucker was sporadic in its distribution throughout the study area and occurred only in small numbers (Table 5). Longnose suckers were typically found individually, but occasionally they were observed within schools of other sucker species. 4.5.4 Quillback sucker Quillback sucker occurred in a few small, isolated groups in sections 4 through 6 and sections 11 through 12 (Tables 5 to 7). Its distribution may be linked to specific habitats, although no obvious habitat observations were made at capture locations. Quillbacks were observed individually or in small schools of up to four fish. The species was also observed schooling with other sucker species. Quillback sucker numbers may be low because successful capture occurred late in the study. Confident visual identification was possible only during sampling events occurring in and around that timeframe. Summer resampling allowed for verification of visual identification because of clear‐water conditions. 4.5.5 Flathead chub Flathead chub was observed in the middle and lower sections of the study area and was often the only species captured at sample locations where river habitat was marginal. Flathead chub was relatively continuous in its distribution from section 5 through section 13 and was the only species that appeared more abundant in a downstream progression (Table 5). The species was not captured in section 9; however, the turbid conditions in lower reaches and a focus on larger size‐classes and sport fish species may have resulted in flathead chub being overlooked in this particular section. 4.5.6 Other non‐sport fish species Four other minnow species observed throughout the study were lake chub, emerald shiner, river shiner and longnose dace. Counts of these species were not recorded in order to focus netting and tallying of larger fish and priority species. Likewise, the 27 locations and distributions of these minnow species were not systematically documented. 4.6 Comparison of 2004 and 1990 ‐ 1991 data 4.6.1 Species composition and relative abundance Species composition and species diversity differed slightly between the 2004 and 1990 ‐ 1991 assessments. A total of 18 fish species were captured in 2004 compared with 14 species in 1990 ‐ 1991. Two sport fish species, lake whitefish and lake sturgeon, were represented in 2004 but were not encountered in the 1990 ‐ 1991 study. Three non‐sport fish species, lake chub, river shiner, and longnose dace, were also captured in 2004 but not in the earlier study. Fathead minnow was present in the 1990 ‐ 1991 study, but was absent in 2004. In 1990 ‐ 1991, a total of 858 fish were captured across the 80 sample sites. All fish captured during that study were sport fish and included goldeye, mooneye, walleye and sauger. In 2004, a total of 282 fish of these four species were captured across 109 sample sites ¿ (Figure 9). In 2004, the combined totals of all sport fish and non‐sport fish species was 429 fish, exactly half the 1990 ‐ 1991 capture total represented by only the four sport fish species. No fish were captured in 19 of 90 (21%) of sample sites in 2004. In comparison, only 9 of the 80 sites (11%) sampled in 1990 – 1991 resulted in zero captured fish. Combined observed and captured fish totals between the two studies using data from the initial capture event in 2004 showed a 70% decrease in total fish abundance between study years, and a 26% decrease when data for 2004 included captures from initial sampling and resampling (Figure 10 and Table 8). ¿
The 2004 study area included 10 additional sample sites more than the 1990 – 1991 study, and 19 sites were resampled. 28 800
Fish Captured in 1990-1991 assessment
700
Fish Captured in 2004 initial assessment and
resampling combined
Number of fish
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Figure 9. SAUG
WALL
MOON
Comparison of capture results for sport fish species between assessments in 1990 – 1991 and 2004 on the Lower Red Deer River. 1400
1990-1991 combined observed and captured fish totals
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2004 combined observed and captured fish totals from
initial sample event
Number of fish
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Figure 10. Comparison of capture results of fish species between assessments in 1990 – 1991 and 2004 (initial sampling event) on the Lower Red Deer River. 29 Table 8. Comparison of fish species totals and percent composition between assessments in 1990 – 1991 and 2004 on the Lower Red Deer River using data from sites common to both assessments (n = 80 sites). Species GOLD WHSC SAUG SHRD LNSC WALL BURB MOON QUIL NRPK MNWH FLCH LKWH LKST TOTAL a
1990 – 1991 species totals n Percent 1,229 59.3 205 9.9 198 9.5 188 9.1 56 2.7 53 2.6 34 1.6 34 1.6 31 1.5 11 0.5 4 0.2 29 1.4 a
0 NC a
0 NC 100 2,074 2004 species totals all sample events n Percent 671 43.5 180 11.7 132 8.5 321 20.8 11 0.7 57 3.7 38 2.5 34 2.2 18 1.2 32 2.1 9 0.6 32 2.1 6 0.4 3 0.2 100 1,544
2004 species totals initial event only n Percent 220 43.6 22 4.4 80 15.8 42 8.3 8 1.6 16 3.2 26 5.1 33 6.5 1 0.2 18 3.6 8 1.6 22 4.4 6 1.2 3 0.6 100 505 NC ‐ not captured. A comparison of only those sections sampled in both assessments and using data only from the initial sample event in 2004, revealed a significant decline (nearly five‐fold) in total fish abundance (based on combined totals for observed and captured fish for all species, excluding cyprinids) from 25.5 fish/km in the 1990 – 1991 study to 5.3 fish/km in 2004 (P = < 0.0001, df = 79; Table 9). Species composition (percent of each species) was similar across studies but overall abundance was typically different (Table 8). Goldeye was the most abundant species (highest percent composition) in the LRDR in both studies. The absolute number of goldeye captured was 16% lower in 2004 than in 1990 ‐ 1991 (Table 8). There was also a significant decrease in relative abundance between studies from 15.36 fish/km in 1990 – 1991 to 2.66 fish/km in 2004 (Table 9). Percent species composition was similar between 30 Table 9. A comparison of fish abundance between sites sampled in 1990 ‐ 1991 and 2004 assessments. Paired t‐test results are based on 80 sites sampled in both assessments. Species GOLD SAUG WALL MOON MNWH NRPK LKWH LKST WHSC QUSC SHRD LNSC BURB *Total combined 1990 ‐ 1991 mean fish/km 15.36 2.48 0.66 0.43 0.05 0.14 0.0 0.0 2.6 0.39 2.35 0.70 0.43 25.5 2004 mean fish/km 2.66 0.99 0.20 0.41 0.10 0.09 0.08 0.13 0.2 0.0 0.25 0.10 0.29 5.30 p‐value < 0.0001 0.0001 0.005 0.4795 0.1602 0.7912 0.0793 0.1602 0.0002 0.0002 < 0.0001 0.04 0.8230 < 0.0001 Degrees of freedom 79 79 79 79 79 79 79 79 79 79 79 79 79 79 *Excludes cyprinid species. studies for white sucker and sauger (Table 8); however, abundance (mean number of fish/km) of both species was significantly less in 2004 than in 1990 ‐ 1991, with declines from 2.48 fish/km to 0.99 fish/km for sauger, and 2.6 fish/km to 0.2 fish/km for white sucker (Table 9). Of the remaining sport fish species, percent composition of walleye in the samples was similar between studies (Table 8), but abundance declined from 0.66 fish/km in 1990 – 1991 to 0.20 fish/km in 2004 (Table 9), and mooneye showed no significant change in abundance between studies (Table 9). Other species for which percent composition was similar between studies, but that significantly declined in terms of abundance between 1990 ‐ 1991 and 2004 included quillback suckers (0.39 fish/km to 0 fish/km; Table 9), shorthead redhorse (2.35 fish/km to 0.25 fish/km; Table 9), and longnose sucker (0.70 fish/km to 0.10 fish/km; Table 9). Percent composition in the sample between study years was similar for the remaining sport fish species including burbot, mountain whitefish, northern pike, lake whitefish and lake sturgeon, and no significant changes in abundances were found (all P values from 0.08 to 0.82, df = 79; Table 9). 31 4.6.2 Species presence and distribution There were many similarities in fish distributions between the 1990 ‐ 1991 and 2004 assessments. Of note, however, is that sections 4 and 5 in the 1990 ‐ 1991 assessment were sampled in the fall, whereas the remainder of sections (in both studies) were sampled in the summer (July). Nonetheless, several general trends in distribution across sample sections remained constant between studies. In particular, in both studies, a stretch of low fish abundance and low species diversity occurred between sections 6 through 9 (Figures 11 and 12). Individual species tended to show similar distributions between the two assessments in regards to fish presence per section and species patterns of distribution through the study area (Figure 11). In both assessments, goldeye and shorthead redhorse were relatively continuously distributed through the study area. Sauger was also widespread throughout the study area during both assessments, although there was more discontinuity in its distribution in 2004. Mountain whitefish and mooneye occupied mainly the upper portion of the study area in both assessments, with additional occurrences of mooneye further downstream in 2004. In both assessments, walleye was similarly distributed throughout the study area occupying upper and lower portions of the river, although there appeared to be a reduction in its range in 2004. In 2004, northern pike occurred further upstream than in 1990 ‐ 1991. Quillback sucker seemed to exhibit a reduction in its range in 2004 compared to the 1990 ‐ 1991 study; however, its disjunct distribution pattern was similar in both assessments. In terms of fish presence by location, white sucker was similarly distributed in both assessments, although its range in 2004 had receded further upstream and was more disjunct. In both assessments, burbot occurred throughout most of the study area, but was absent around section 9. The distribution of longnose sucker was broader and more scattered in 2004 than in 1990 ‐ 1991. Flathead chub had a similar distribution in both assessments, with occurrences from the middle sections (sections 5 and 6) downstream; although, the species was found slightly further upstream in 2004. Lake sturgeon and lake whitefish, present in low numbers in some 2004 sample sections, were not represented in the 1990 ‐ 1991 assessment, precluding a comparison of their distributions between the two assessments. 32 ACA & ASRD, 2004
F & W 1990-1991
End of Survey
FLCH
FLCH
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Figure 11. Fish species presence by section in the Lower Red Deer River, 1990 ‐ 1991 and 2004. 33 13
Border
12
Bindloss
11
Buffalo
10
Jenner
9
Dinosaur
8
Emerson
7
Finnegan
6
Dorothy
5
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HWY 590
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WALL
Section
13
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Emerson
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5
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WALL
Section
Figure 12. Combined observed and capture totals per sample kilometer, 1990 ‐ 1991 and 2004. 4.6.3 Percent composition by species by section Goldeye The percent composition of goldeye by section differed between the 1990 ‐ 1991 and 2004 assessments. In 2004, goldeye abundance increased in a downstream progression with a spike in abundance in section 6, whereas in 1990 ‐ 1991 goldeye abundance declined steadily in a downstream direction with a drop in the middle sections 5 through 7 (Appendix 4). Mooneye Mooneye percent composition by section was similar between the two assessments with the vast majority of mooneye captured in the upstream‐most reaches, mainly in section 1 (Appendix 4). Walleye The percent composition of walleye per section was considerably different across the two studies. In the 1990 – 1991 assessment, walleye were encountered throughout the study area with an increase in abundance toward the lowest reaches (sections 9 to 11). In 2004, walleye showed a similar increase in abundance toward the lowest reaches 34 (sections 9 to 13), but the vast majority were encountered in section 1 (Appendix 4). In 2004, no walleye were captured or observed in sections 2 through 9 during initial sampling, however three of these sections were later resampled and all yielded walleye. Sauger In both the 1990 – 1991 and 2004 assessments, sauger were uniformly distributed throughout the study area. In 1990 – 1991, sauger were encountered more readily in the mid to upper reaches of the study area, whereas in 2004 sauger tended to occur in the lowest reaches. As with goldeye, the location of highest sauger occurrence was almost inverse in nature between the two assessments. In 2004, sections 3 through 7 yielded the lowest percentage of sauger, in contrast to the 1990 ‐ 1991 assessment where these sections yielded the highest proportion of sauger (Appendix 4). Shorthead redhorse Shorthead redhorse displayed similar patterns in percent distribution between assessments. The uppermost reaches accounted for similar percentages of the species totals in both assessments and there was a decline in occurrence in section 2 common to both assessments. Similarly, in both assessments, the lower reaches of the study area accounted for an increasing percentage of the species total (Appendix 4). 4.6.4 Total fish abundance by section Total fish abundance by section was substantially higher throughout the study area in the 1990 ‐ 1991 assessment. Similarities in total fish abundance across the 1990 – 1991 and 2004 assessments included the highest abundance occurring in section 1, and low abundance in sections 7 and 8 (Dorothy to Highway 36 bridge at Emerson campground). Observed total abundance during clear‐water resampling in 2004 matched closely with 1990 ‐ 1991 abundance totals; however, there was a sharp increase in abundance in section 5 in 2004 which mirrors a similar but smaller increase in this section in 1990 ‐ 1991 (Figure 12). Statistical comparison of total fish abundance between 2004 clear‐water resampling and data from 1990 ‐ 1991 showed no significant difference between assessments, with an average total number of fish per site of 33.3 fish/site in 1990 ‐ 1991 and 47.7 fish/site during 2004 resampling (P = 0.086, df = 18). 35 4.6.5 Fish measurement summaries A comparison of measurement data between 2004 and 1990 ‐ 1991 assessments revealed similar size ranges for the four primary sport species (goldeye, mooneye, walleye, and sauger, Table 10). Overall, fish in the 2004 assessment were older than the previous study and maximum fork lengths for walleye and sauger were larger. 4.6.6 Sauger age and length measurement relationships The age‐length relationship for sauger in 2004 suggests a potential increase in growth rate since the 1990 ‐ 1991 assessment (Appendix 5). The von Bertalanffy growth constant shows a three‐fold increase between the two assessments also indicating an increase in growth rate. Consistent with the age‐length profile, it appears that mean length‐at‐age also increased slightly between assessments (Appendix 5). Sauger FL distributions varied between assessments. In 1990 ‐ 1991, sauger FL ranged from 280 to 470 mm, whereas in 2004 FL varied from 190 to 490 mm. (Appendix 5). In 2004, the strongest year classes for sauger were 1997 and 1998 corresponding to age‐
6 and 7 fish (Appendix 5). The overall age profile for sauger in 2004 showed a symmetrical range of ages‐3 to 10, whereas the sample from 1990 ‐ 1991 study showed a less symmetrical age‐class distribution but the same range of age classes were represented. There was an abundance of age‐4 and 5 fish representing 1986 and 1987 recruitment years from the 1991 sample, but also strong age‐4, 5 and 7 classes from the 1990 sample, representing 1983, 1985, and 1986 recruitment years. 36 Table 10. Comparison of sport fish measurements between assessments in 1990 ‐ 1991 and 2004 on the Lower Red Deer River. Fork Length (mm) Species n Weight (g) Age (y) Goldeye 2004 Goldeye 1990‐91 173 319 Max 401 410 Min 207 141 Mean 320 329 S.D. 26 37 Max 730 770 Min 195 30 Mean 366 399 S.D. 97 136 Max Min Mean S.D. 9 7 4 1 6 5 1 1 Mooneye 2004 Mooneye 1990‐91 31 22 296 295 244 223 268 256 12 20 296 350 244 70 268 212 14 66 9 7 5 3 6 5 1 1 Sauger 2004 Sauger 1990‐91 62 115 489 464 189 273 359 357 60 40 1,210 1,000 50 110 458 436 234 163 10 10 3 3 6 6 2 2 Walleye 2004 Walleye 1990‐91 16 30 708 691 143 135 449 322 179 131 4,230 4,010 25 20 1,411 533 1,363 817 14 10 3 1 7 4 3 2 37 4.6.7 Walleye age and length measurement relationships The age‐length relationship for walleye in 2004 indicated that fish of a given age attained a greater length compared to 1990 ‐ 1991, suggesting an increase in growth rate. However, no feasible solution could be calculated for the von Bertalanffy growth equation using data from 1990 – 1991, precluding a direct comparison of growth rates between assessments (Appendix 6). A comparison of mean length‐at‐age between the two assessments revealed an apparent reduction in mean length occurring at around age‐6 in both surveys (Appendix 6). In 2004, the walleye FL distribution showed a wider range of fish > 550 mm, whereas in 1990 ‐ 1991 no walleye were represented in the 450 to 650 mm FL range (Appendix 6). Few walleye were captured in 2004 (n = 16); however, a broad range of year‐classes was represented and successful recruitment occurred for seven consecutive years between 1995 and 2001 (Appendix 6). Comparatively, fewer year classes were recorded in the 1990 ‐ 1991 survey and the years 1980, 1982, 1983 and 1985 were not represented in either samples suggesting years of less successful recruitment. Combined walleye totals from the 1990 ‐ 1991 study show strong recruitment in 1986, 1987, and 1988, as well as highly successful recruitment in 1990 with abundant age‐1 fish in the 1991 assessment. Successful recruitment prior to the 1990 ‐ 1991 survey occurred for five consecutive years from 1986 to 1990 (Appendix 6). 4.6.8 Goldeye age and length measurement relationships The age‐length relationship for goldeye in 2004 indicated that, for a given age, goldeye tended to be smaller compared to the 1990 ‐ 1991 assessment, suggesting a potential decrease in growth rate. However, no feasible solution could be calculated from the von Bertalanffy growth equation (Appendix 7). Goldeye mean length‐at‐age was consistent with the age‐length slope, showing an apparent decrease in slope compared to the 1990 ‐ 1991 assessment, indicating a slower growth rate (Appendix 7). In 2004, goldeye had a narrower fork length distribution than in 1990 ‐ 1991, although strong representation around the 300 to 320 mm range was consistent between the two 38 studies (Appendix 7). However, the distribution from 2004 appears to be truncated around 330 mm. In 2004, the goldeye sample consisted mainly of age‐5 and 6 fish (1998 and 1999 year classes), whereas in 1990 and 1991 the samples contained primarily age‐4 fish representing 1986 and 1987 year classes (Appendix 7). 4.6.9 Mooneye age and length measurement relationships Age‐length relationships for mooneye suggested that in 1990 ‐ 1991 fish of a given age attained a greater length than in 2004. However, no feasible solutions could be calculated from the von Bertalanffy growth equations (Appendix 8). A comparison of mean length‐at‐age for mooneye between the two assessments showed virtually no change in growth rates (Appendix 8). In 1990 ‐ 1991 mooneye FL ranged from 230 to 270 mm; broader than the 2004 size range which included no individuals smaller than 250 mm (Appendix 8). The lack of representation of small size classes in the 2004 sample is likely a factor in the difference in age‐length relationships between the two assessments. In 2004, the strongest year classes for mooneye were 1997 and 1998 corresponding to age‐7 and 6 fish, respectively. In 1991, age‐4 and 5 mooneye were the strongest age‐
classes, representing 1987 and 1986 (Appendix 8). 4.6.10 Species not compared between assessments Fork‐length measurement data collected in 2004 on burbot and three non‐sport species that were not collected in 1990 ‐ 1991 provided frequency distributions that may be used for future comparisons (Appendix 9). 39 5.0 DISCUSSION 5.1 Capture success in the 2004 assessment During the 2004 fish assessment on the LRDR, it became readily apparent that capture success was extremely low and that sampling was not yielding the desired results. Inefficiency in successful fish capture during the assessment was likely due to a number of factors described in the following sections (5.1.1 and 5.1.2). 5.1.1 Effects of turbidity Fish capture success in the upper reaches of the study area was greater than in lower reaches (Figure 5) and was likely due to water clarity. Turbidity is likely beneficial to fish capture success because it decreases the chance of visual avoidance by fish and increases the element of surprise by samplers. When turbidity was recorded as high, CPUE was comparatively higher than when water was clear. In the upper reaches of the study area the water was turbid during the time of sampling (Appendix 2). Sections 1 and 2 (from km 470 to 390) were extremely turbid with water clarity ranging from 0 to 60 cm, and CPUE was highest in these reaches. After section 2, from the Tolman Bridge downstream, the water became increasingly clear as water levels declined, and capture success subsequently decreased (Table 3). 5.1.2 Confounding effects of water clarity, volume and conductivity The LRDR is typically wide, slow and flat. Floating this type of water simply pushed schools of fish ahead of the boat and out of range of the electrofisher. Throttling forward while electrofishing only succeeded in scattering schools of fish. In contrast, fish in faster, steeper grade water tended to hold in currents and were captured readily during clear water conditions as the boat drifted quickly overhead. Fish in the LRDR are free to swim in a lacustrine‐type environment and can readily avoid the sampling boat. Deep pools were encountered and fish were visible but were unaffected by shocking. Evidently, boat‐electrofishing of slow, wide, prairie rivers such as the LRDR may be intrinsically ineffective. 40 Water conductivity ranged from 378 to 392 microsiemens and may have increased electrofishing inefficiency as levels > 200 microsiemens are considered high by local guidelines (Montana Fish, Wildlife & Parks 2002; ASRD 2004). High conductivity limits the electrical field radius (Smith‐Root 2003). The combined effects of clear water (McInerny and Cross 2000), high conductivity (Hill and Willis 1994) and depths exceeding the capabilities of the sampling equipment may have lead to poor capture efficiency. Under the existing sampling conditions, fish easily avoided the smaller electrical field because of the water clarity and volume, especially in deep pools. Consequently, the sampling method used was inefficient for a river under the given conditions. Night electrofishing is one method commonly used to counter the effects of avoidance in lentic environments (McInerny and Cross 2000), and more efficiently uses a smaller electrical field; however obvious safety concerns arise when electrofishing and navigating shallow, flowing waters in darkness. 5.2 Methodology 5.2.1 Alternative capture techniques Fish measurements and samples are required to determine population size and age class demographics. The following alternative capture techniques would increase the number and range of representative individuals in samples. 5.2.2 Throwing anode A throwing anode would likely significantly increase capture success in slow, open‐
channel sections with high water clarity. Fish that were just out of reach of the electrical field of the booms could have been captured more effectively by landing a throwing anode into some of the large schools which were only a short throwing distance away. This method would result in a greater proportion of observed fish being captured. A throwing anode would also increase success in deep pools where fish were observed but were unaffected by shocking. Probing down into deep pools would bring the electrical field to depths that the booms could not attain. This technique would be ideal for capturing species of special interest. Results from this study provided little insight regarding walleye and quillback suckers, species of 41 particular interest in terms of their management and conservation. A throwing anode would allow for selective sampling of these species during clear water conditions and collection of larger samples. 5.2.3 Angling Selective sampling of target species could be achieved through angling. Species such as walleye and sturgeon, which inhabit pools often too deep to electrofish, are readily captured by angling with bait. In some instances, sight angling could have been applied during the 2004 assessment where large walleye were observed in deep pools, lying stationary on the bottom out of range of the electrofisher. A baited hook carefully positioned directly in front of these fish may have enhanced capture of walleye and also enhanced representation of the largest walleye size classes (Jensen, pers. comm. 2004). Angling also may have increased capture of sturgeon. Only one individual was captured through electrofishing. Other individuals were observed but were either too deep to capture or too powerful to be contained in the electrical field. Angling has proven a highly successful technique to sample a wide range of sizes and age classes of sturgeon on past surveys in the South Saskatchewan River (RL & L 1997). 5.2.4 Higher electrical output An additional means of increasing capture efficiency in the lower, slower water reaches, may be the use of an electrofisher and generator with higher output potential. Some fish were only slightly affected by the electrical field and immediately darted away. This result is because the field is not large enough to encompass the fish, the field is not intense enough to elicit taxis, or a combination of both factors. Greater power potential would increase the size and intensity of the electrical field allowing fish to be reached at greater depths and distances (Miranda and Dolan 2004). In extreme conductivity, electrofishing is most effective and least damaging to fish when using low voltage with high current (amps) (Smith‐Root 2003). Under these configurations, however, the limiting factor then becomes the rating of the electrofisher unit and generator required to administer adequate current (Smith‐Root 2003). Use of such equipment would alleviate power limitations and allow for a larger electrical field with sufficient current amplitude to elicit taxis. 42 5.3 Measuring total fish abundance and distribution Use of CPUE to estimate relative fish abundance in the 2004 assessment may not have been the most reliable method to estimate relative abundance. Values may not have reflected total fish abundance per section due to the effects of turbidity. CPUE was typically highest when turbidity was high and lowest when water clarity was high. Also observed was an unequal capture efficiency among species resulting in greater CPUE for some species than others. For example, sauger were effectively stunned and relatively easily netted, however quillback sucker, pike and shorthead redhorse were significantly more difficult to capture. Including numbers of observed fish in CPUE calculations, as was done in the 1997 study by RL & L, was not feasible for the 2004 study. Output duration was sustained at somewhat regular on/off intervals throughout the study and total fish (observed and captured) per unit effort should be an indicator of fish tallied per unit of time spent on the river. However, the variation in water clarity between sites inevitably skews the results so that clearer sections will always have higher CPUE because of the influence transparency depth has on visual counts. Combining captured and observed fish totals, was therefore the most reasonable means to measure abundance in order to compensate for the effects of water clarity on capture efficiency. In clear water, CPUE was lower but visual counts were higher, whereas in turbid water CPUE was higher but visual counts were lower. This means of measuring total abundance also allowed for easier comparison with the 1990 ‐ 1991 assessment, from which effort was unavailable. The most efficient means of determining relative abundance is likely visual counts during high water clarity. Of the total fish tallied in the study, 58% resulted from visual counts conducted during resampling of sections 3 through 6 in clear water. Observed fish totals during resampling were significantly higher than combined totals (observed and captured) during initial sampling when conditions were recorded as turbid (Figure 8). In clear water, schools of readily identifiable fish species outside the electrical field radius were accounted for by visual sampling. Consequently, the sample area surveyed increased in size from the immediate proximity of the 43 electrofishing boat to a visual radius surrounding it. However, drawbacks to visual counts include increased observer subjectivity, inability to see or count smaller species and size classes, and potential misidentification of species depending on the experience level of the observers. 5.4 Comparing relative abundance Significant changes in abundance were observed between the 1990 ‐ 1991 and 2004 assessments. Total fish captures were significantly lower in 2004 for nearly every species, with a three‐fold decrease in total capture success of the four primary sport species in the river (goldeye, mooneye, walleye, and sauger, Figure 9). The difference between studies may be attributed to a variety of factors, not excluding a general population decline in the river. 5.4.1 Capture efficiency A comparison of species totals, and overall total abundance data, between the two assessments suggested a significant decline in fish abundance. However, the difference in abundance between studies also may be linked to poor sampling efficiency in 2004. It has been shown that captured versus observed totals were vastly different in 2004 and that equipment issues were suspected. Considering numbers of fish observed by visual counts in clear water conditions, it is apparent that a large proportion of the fish present were not accounted for in capture totals (Figure 8). Combined 2004 resampling totals compared with combined 1990 ‐ 1991 totals, however, displayed quite similar combined total abundances per section, with no statistical difference (Figure 12). It is possible that combined observed/captured totals during initial sampling in 2004 were lower than 1990 ‐ 1991 totals simply because the “capture” component was so inefficient in 2004. If the equipment used in 2004 was not as efficient as it was in 1990 ‐ 1991, then 2004 clear water resampling might be a more comparable measure of abundance with 1990 ‐ 1991 results. Water clarity during 2004 resampling may have made possible the visual counting of a proportion of fish that would have been captured in the previous assessment but were not represented during initial sampling of 2004, and as a result would more accurately represent the combined sample efficiency (visual observation and captured fish) of the 1990 ‐ 1991 assessment. If so, 44 this would indicate there was no significant change in relative total fish abundance between the two assessments. However, this is based only on 19 sample locations and does not account for seasonal sampling differences between studies, as sections 4 and 5 were sampled in the fall of 1990 ‐ 1991, but during the summer in 2004. 5.4.2 Population decline It is possible that the 2004 assessment data accurately reflect a decline in fish abundance in the LRDR. Despite suspected sampling inefficiency in 2004, sections 1 through 11 were sampled using the same electrofishing equipment, similar crew experience, and personnel present during the 1990 ‐ 1991 assessment. While clear water visual counts in 2004 yielded larger abundance totals during resampling than during the initial sample event, it is possible that given the same water conditions in 1990 ‐ 1991 the same differences in abundance would have resulted. 5.4.2.1 Effects of Drought Average monthly flow data from the years immediately prior to the two assessments supports a general decline in fish numbers. Low stream flow is considered the primary cause for sauger declines in Montana, impeding spawning migrations, larval drift, and decreasing the availability of suitable offstream and tributary spawning and rearing areas (Schmidt et al. 2002; Jaeger 2004). Both mooneye and goldeye are dependent on water temperatures as a cue to spawn (Nelson and Paetz 1992; Schmidt et al. 2002), and are fluvial specialists (Barko et al. 2004) depending on the spring flood pulse for downstream transport of floating eggs and larvae (Nelson and Paetz 1992; Jorgensen 2003). When river discharge at Red Deer drops below 50 m3/sec, the channel‐bed becomes more exposed (at which point jet boat operation is unsafe). Prior to 1990 sampling, combined spring averages fell below this level for three consecutive years between 1983 to 1985 and then again for two years in 1987 to 1988 (Environment Canada, 2003). Prior to the 2004 assessment, spring averages were below this level for four consecutive years. Although there were more combined drought years prior to the 1990 assessment, there was a longer continuous drought period prior to the 2004 assessment (Table 11). The four year drought prior to 2004 probably had deleterious 45 effects on the entire fish community, and could have accounted for the observed overall decline of nearly all fish species (Figure 10). Table 11. Lower Red Deer River spring discharges at Red Deer during typical spring runoff months, and drought sequences preceding assessments in 1990 – 1991 and 2004. Recruitment Year Monthly Discharge (m3/sec) Runoff May June May + June 2004 survey mean median mean median mean 1997 75.4 61.0 103.0 89.6 89.2 1998 46.7 32.0 140.0 105.0 93.4 1999 30.1 28.8 36.4 30.8 33.3 2000 30.6 27.8 37.5 37.0 34.1 2001 30.4 22.0 61.7 60.2 46.1 2002 38.4 36.8 54.9 46.7 46.7 2003 134.0 136.0 92.8 89.8 113.4 May June May + June 1990‐91 survey mean median mean median mean 1983 57.4 54.8 22.6 21.0 40.0 1984 44.0 34.4 23.4 21.8 33.7 1985 24.2 21.9 30.1 31.9 27.2 1986 99.3 56.1 101.0 86.3 100.2 1987 36.6 39.0 37.6 37.0 37.1 1988 19.3 18.1 37.1 40.7 28.2 1989 55.8 54.7 61.9 61.0 58.9 1990 109.0 69.8 312.0 276.0 210.5 Shaded areas denote years of low average spring flow. 5.4.2.2 Recruitment as an indicator If low flows have contributed to the decline in total fish abundance, it would be expected that in years of low flow during spring runoff, that lower recruitment and/or survival would be expected than in years of average or above average flows. Walleye, sauger, goldeye and mooneye are all spring spawners and influenced by spring runoff events. Year‐class structures for these species at the respective sampling dates provided insight into the effects of low spring flows on recruitment levels. Of the fish sampled in the 2004 assessment, 1998 proved to be the strongest recruitment year for 46 goldeye, mooneye and sauger. Similarly, 1998 was also the year of the highest average June flows at 140 m3/sec (Table 11), as well as the highest combined monthly average discharge during the spring runoff (May and June combined) in a seven‐year span (the approximate mean age of all captured fish). The year with the next most successful recruitment numbers was 1997, which also had near average June flows at 103 m3/sec, in contrast to consecutive drought years 2000 through 2003, which were well below the average of 122 m3/sec and consequently showed low recruitment for these species (Figure 13 and Table 11). Similar evidence for the effects of spring flows on fish numbers and recruitment survival are evident from the 1990 ‐ 1991 data. June flows in 1986 approached the historic average at 101 m3/sec, and subsequent recruitment was higher (Figure 14). Similarly, the 1990 average June flows were the highest in over 60 years (Table 11) and resulted in a successful year class (age‐1) of walleye captured in 1991 (Appendix 6).
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Figure 14. Mean June discharge and percent fish recruitment from the 1990 ‐ 1991 total fish sample. 5.5 Comparing species distributions 5.5.1 Effects of habitat and channel characteristics There is a general trend in the 1990 ‐ 1991 and 2004 assessments of declining fish abundance in a downstream progression. High relative abundance in the upper sections, but low abundance in the lower sections is likely a consequence of habitat and channel characteristics. In section 1 for example, the narrow channel in the upstream portion of the study area concentrates fish, thereby increasing the probability of capture compared to the wide, open channel in downstream reaches where fish may be more scattered and are less likely to be encountered. Therefore, as the channel widens, the probability of encountering fish likely decreases. In addition, differences in habitat variety also likely impacted local species abundance and richness, as a diversity of habitat is strongly related to species richness (Koel 2004). Upstream reaches had a greater variety of fish habitats such as riffle areas, side channels and eddies, and more woody debris from the surrounding vegetation. Downstream reaches were typically more homogenous, slow, shallow run areas with limited variety of habitats. 48 5.5.2 Species diversity Despite the dramatic decrease in total abundance from 1990 ‐ 1991 to 2004, greater species diversity was observed in the 2004 assessment, likely a consequence of the larger study area. The 1990 ‐ 1991 assessment terminated at section 11 so there was no data for comparison in sections 12 and 13. However, according to 2004 trends in abundance (Figure 6) and species distribution patterns (Figure 11), section 13 where the Red Deer and South Saskatchewan rivers converge, is likely to contain the greatest species diversity and total abundance. Section 13 was sampled at only two of a possible seven sites because of mechanical failure; however, there was an increasing trend in the number of species and fish abundance. It is suspected that species diversity and abundance should increase closer to the confluence with the South Saskatchewan River as species more common to that river, such as silver redhorse, quillback sucker and lake sturgeon (RL & L 1997) become increasingly prevalent. 5.5.3 River productivity The LRDR assessment resulted in fish numbers that were relatively low. Even when observed fish totals were included, fish populations in the lower stretches of the Red Deer River were modest considering the length and intensity of the study. The total of captured and observed fish from all sampling, resampling and catchability runs combined in 2004 was 1,544 fish. Considering this total was based on a study section of a combined 109 km or 109,000 m of direct sampling, the results are only 14 fish/km, or less than 2 fish/100 m of river sampled. In contrast, total fish abundance in 1990 – 1991 was 2,074 fish in 80 km of river sampled, or about 26 fish/km or just under 3 fish/100 m of river. Overall, we agree with Longmore and Stenton’s assessment (1981) that the LRDR displays low productivity, typical of turbid, low‐light, low‐oxygen, warm‐water rivers (Kalff 2001). Thus, apparent declines in fish abundance should be met with added concern, considering the inherently low fish productivity in the LRDR and the potential challenges for recovery. 49 5.6 Potential effects of angling Anecdotal evidence suggests that sauger catch rates may be increasing, which contradicts data from 2004 that suggest an overall decline in fish numbers. However, angler perceptions may prove accurate. Stream flows have been well below average over the past four to five years, thereby concentrating fish populations into smaller areas. Consequently, the probability of finding a fish increases and the density of individuals in a particular area is greater, resulting in greater angler success. Increased angler success may confound the effects of low flows by increasing hooking mortality and angler harvest. An angler creel survey on the LRDR would help address anecdotal evidence of increased catch rates, as well as help identify factors contributing to the apparent decline in fish numbers, by providing more accurate measures of angling pressure, angler success, angler harvest and species targeted by anglers. 5.7 Future considerations and recommendations 5.7.1 Lower Red Deer River sampling •
Sections 1 through 9: Sampling to determine abundance and distribution should be conducted during clear water conditions via visual counts by experienced observers using tally‐counters, where water velocity and turbulence is low. Sub‐samples of fish from counted schools could be collected using a throwing anode visually. In swift water and areas of dense fish cover, sampling should be conducted using traditional boat electrofishing. This procedure is intended to provide a more accurate depiction of species composition while maintaining fish data requirements. •
Sections 10 through 13: In sections that are turbid throughout the year where capture efficiency is good and where visual counts are not, traditional boat electrofishing should be used as the primary sampling method with an electrofishing unit capable of greater electrical output. Supplemental sampling via angling should be conducted in deep pools where electrofishing is not effective. Sampling should be completed in section 13, the lowest reach in the study area, to the confluence with the South Saskatchewan River to provide a 50 more complete assessment of the river and insight into the role of river connectivity on species abundance and distributions. •
Selective sampling for walleye, quillback sucker, and lake sturgeon should be conducted using a throwing anode and angling to enhance capture and reduce data deficiencies pertaining to these species in the LRDR. Sampling effort should be concentrated at locations where these species are known to be most prevalent. •
Sampling from the Dickson Dam downstream to Joffre should be conducted to complete the LRDR inventory and should include cold‐water species such as trout and whitefish. Additional sampling of minnow species via seining or trapping should also be considered in order to construct a comprehensive database of fish communities in the Red Deer River and their interactions. 5.7.2 •
Addressing potential population declines An angler creel survey should be conducted on the LRDR to quantify angler harvest and the potential effects of hooking mortality on sport fish populations. This information would help explain apparent declines in fish populations and address anecdotal evidence of increased sauger catch rates. •
An in‐depth habitat assessment should be conducted along the LRDR to establish in‐stream flow needs and habitat criteria required to sustain fish populations, particularly in light of planned water allocation changes in the South Saskatchewan River Basin. •
Long term population monitoring of declining sauger and goldeye populations should be initiated. 5.7.3 •
Data deficient species Focused investigations on sauger and quillback sucker populations in the LRDR to the South Saskatchewan River confluence, and in other southern Alberta 51 rivers, should be conducted and compared to enhance knowledge of these species and better monitor their status and distributions. 52 6.0 LITERATURE CITED Alberta Environment. 2004. Alberta’s river basins. Available online at: http://environment.alberta.ca/apps/basins/default.aspx. [Accessed 2004]. Alberta Sustainable Resource Development. 2001. The general status of Alberta wild species 2000. Alberta Environment / Alberta Sustainable Resource Development, Edmonton, Alberta, Canada. 46 pp. Available [online] http://www.srd.alberta.ca/fishwildlife/speciesatrisk/generalstatus.aspx. Alberta Sustainable Resource Development. 2004. Electrofishing policy respecting injuries to fish: Alberta electrofishing guidelines. Alberta Fisheries Management Branch, Edmonton, AB. Barko, V., M. Palmer, D. Herzog, and B. Ickes. 2004. Influential environmental gradients and spatiotemporal patterns of fish assemblages in the unimpounded Upper Mississippi River. American Midland Naturalist 152: 369‐386. Buchwald, V. Pers. Comm. Contacted May 2003. Area Fisheries Biologist. Alberta Sustainable Development, Red Deer, Alberta. Email: [email protected]. Cooper, J., and T. Council. 2004. Assessment of the distribution and relative abundance of sport fish in the lower Red Deer River (Phase I). Data report (D‐
2004‐004) produced by Alberta Conservation Association, Lethbridge, Alberta, Canada. 22 pp + App. Environment Canada. 2003. Near real‐time water level information: Red Deer River at Red Deer, archived hydrometric data. Updated March 14, 2003. http://www.wsc.ec.gc.ca/hydat/H2O/index_e.cfm?cname=graph.cfm&RequestTi
meout=300. [accessed 3 March 2005]. Golder (Golder Associates Ltd.). 2003. Strategic overview of riparian and aquatic condition of the South Saskatchewan River Basin. Prepared for Alberta Environment, Edmonton, Alberta. 53 27 pp + 9 App. [online] http://www3.gov.ab.ca/env/water/regions/ssrb/pdf_phase2/SORAC_Report_co
mplete.pdf. Hill, T., and D. Willis. 1994. Influence of water conductivity on pulsed AC and pulsed DC electrofishing catch rates for largemouth bass. North American Journal of Fisheries Management 14: 202‐207. Jaeger, M. 2004. Montana’s fish species of concern: sauger. Montana Cooperative Fisheries Research Unit, Montana Chapter of the American Fisheries Society, Bozeman, Montana. Updated 2 March 2005. http://www.fisheries.org/AFSmontana/SSCpages/Sauger%20Status.htm. [Accessed 4 March 2005]. Jensen, B. Pers. Comm. Contacted January 2004. Conservation Officer. Alberta Sustainable Resource Development, Drumheller, Alberta. Email: [email protected]. Jorgensen, D. 2003. Evaluation of spring rise for the Missouri River. Prepared for: Missouri River Technical Group, Papio‐Missouri River Natural Resources District, Missouri Levee and Drainage Districts Association, and the Coalition to Protect the Missouri, Jefferson, South Dakota. Kalff, J. 2001. Limnology: inland water ecosystems. McGill University, Prentice‐Hall Inc., Upper Saddle River, New Jersey. Koel, M. 2004. Spatial variation in fish species richness of the Upper Mississippi River system. Transactions of the American Fisheries Society 133: 984‐1003. Longmore, L.A., and G.E. Stenton. 1981. The fish and fisheries of the South Saskatchewan River basin: their status and environment requirements. Alberta Energy and Natural Resources, Fish and Wildlife Division, Edmonton, Alberta. 335 pp. 54 Mackay, W.C., G.R. Ash, and H.J. Norris. 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, Alberta. 133 pp. McInerny, C., and T. Cross. 2000. Effects of sampling time, intraspecific density, and environmental variables on electrofishing catch per effort of largemouth bass in Minnesota Lakes. North American Journal of Fisheries Management 20: 328‐
336. Miranda, L., and R. Dolan. 2004. Electrofishing power requirements in relation to duty cycle. North American Journal of Fisheries Management 24: 55‐62. Montana Fish, Wildlife & Parks. 2002. Electrofishing methods policy: Montana electrofishing guidelines. Fisheries Division, Helena, Montana. Nelson, J.S., and M.J. Paetz. 1992. The fishes of Alberta. 2nd edition. The University of Alberta Press, Edmonton, Alberta. 437 pp. R.L. & L. Environmental Services Ltd. 1997. Fisheries inventories of the lower Bow, Lower Oldman, and South Saskatchewan rivers, 1995‐1996. R.L.& L. Report No. 516F, prepared for Alberta Environmental Protection, Natural Resources Service, Fisheries Management Division, Edmonton, Alberta. 90 pp + App. Rood, S.B., C. George and W. Tymensen. 2002. Recreational instream flow needs (R‐
IFN) for the Red Deer River, Alberta. Report for Alberta Environment, Lethbridge, Alberta. 30 pp. Roth, C. 1999. Lower Red Deer map: Drumheller to the Red Deer Forks. Alberta Recreational Canoe Association, Edmonton, Alberta. Swenson, R. 2002. Lakes, rivers, and streams of Alberta, Volume 1: southern basins. Space Maps Incorporated, Spruce Grove, Alberta. 423 pp. 55 Schmidt, K., N. Paulson, and J. Hatch. 2002. Natural history of Minnesota fishes. University of Minnesota. Updated February 16, 2004. http://www.gen.umn.edu/research/fish/fishes/goldeye.html#reproduction , http://www.gen.umn.edu/research/fish/fishes/walleye.html#reproduction , http://www.gen.umn.edu/research/fish/fishes/sauger.html#reproduction , March 4 2005. Smith‐Root Inc. 2003. Selecting a GPP Electrofisher. Updated October 21, 2003. http://www.smith‐root.com/products/electrofishers/select_your_gpp.php. [Accessed 10 March 2005]. von Bertalanffy, L. 1938. A quantitative theory of organic growth. Human Biology 10: 181‐213. 56 7.0 APPENDICES Appendix 1. Location and site summary data for sampling sections on the Lower Red Deer River in 2004. Geographic coordinates specified Universal Transverse Mercator (UTM) coordinates, NAD 83. Section Number and Name River km Easting Northing Effort (s) (Section 13) Bindloss to AB – SK border Total (Section 12) Buffalo to Bindloss Total 0‐1 4‐5 9‐10 14‐15 19‐20 24‐25 29‐30 2 sites 34‐35 39‐40 44‐45 49‐50 54‐55 59‐60 64‐65 69‐70 8 sites 568900 565360 562509 557877 554865 553737 549328 545230 541095 540007 539458 536108 531545 527054 522427 5646470 5646127 5643796 5642809 5642619 5639472 5639266 5641522 5644074 5643112 5638194 5634754 5632519 5634113 5632758 N/A N/A N/A N/A N/A 955 810 1,765 786 552 752 741 762 843 848 857 6,141 57 Total fish CPUE captured (fish/10 min)
N/A N/A N/A N/A N/A 4 16 20 3 6 2 8 3 2 3 5 32 N/A N/A N/A N/A N/A 2.51 11.85 Mean = 7.18
2.29 6.52 1.60 6.48 2.36 1.42 2.12 3.50 Mean = 3.29
Appendix 1. Continued. Section Number and Name River km Easting Northing (Section 11) Jenner ‐ Buffalo Total (Section 10) Dinosaur PP ‐ Jenner Total 74‐75 79‐80 84‐85 89‐90 94‐95 99‐100 104‐105 109‐110 114‐115 119‐120 10 sites 124‐125 129‐130 134‐135 139‐140 144‐145 149‐150 154‐155 7 sites 517907 513873 511802 509212 505100 500834 496491 492220 489760 488005 484713 480634 478100 476214 472304 468067 464412 5633555 5634475 5638050 5641243 5643765 5641796 5640370 5639029 5635299 5631828 5634921 5635402 5631556 5627214 5624157 5623152 5624632 58 Effort (s) 779 834 910 859 905 805 868 901 985 930 8,776 791 788 838 931 925 903 775 5951 Total fish CPUE captured (fish/10 min)
4 3.08 1 0.72 6 3.96 7 4.89 9 5.97 2 1.49 1 0.69 3 2.00 2 1.22 3 1.94 38 Mean = 2.60
1 0.76 4 3.05 6 4.30 6 3.87 9 5.84 6 3.99 5 3.87 37 Mean = 3.67
Appendix 1. Continued. Section Number and Name River km Easting Northing (Section 9) Emerson Bridge ‐ Dinosaur PP Total (Section 8 ) Finnegan Ferry ‐ Emerson Bridge Total (Section 7) Dorothy – Finnegan Ferry Total 159‐160 164‐165 169‐170 174‐175 179‐180 184‐185 189‐190 194‐195 8 sites 199‐200 204‐205 209‐210 214‐215 219‐220 224‐225 229‐230 234‐235 8 sites 239‐240 244‐245 249‐250 254‐255 259‐260 5 sites 460196 457390 456501 452919 448350 444105 441634 439698 435650 431873 434957 434845 433408 431876 429065 425148 422317 418982 415620 412694 409569 5624347 5628297 5632239 5634272 5633497 5632016 5635461 5640160 5640640 5642084 5645006 5648716 5653124 5657748 5660810 5663047 5666333 5669424 5672877 5675978 5678549 59 Effort (s) 804 746 641 848 760 610 534 509 5452 526 638 718 574 614 625 681 778 5154 887 784 765 1025 776 4237 Total fish CPUE captured (fish/10 min)
2 1.49 2 1.61 0 0.00 1 0.71 6 4.74 0 0.00 0 0.00 0 0.00 11 Mean = 1.07
0 0.00 0 0.00 4 3.34 1 1.05 3 2.93 0 0.00 2 1.76 3 2.31 13 Mean = 1.42
0 0.00 10 7.65 0 0.00 5 2.93 12 9.28 27 Mean = 3.97
Appendix 1. Continued. Section Number and Name River km Easting Northing (Section 6) Drumheller ‐ Dorothy Total (Section 5) Bleriot Ferry ‐ Drumheller Total (Section 4) Tolman Bridge ‐ Bleriot Ferry Total 264‐265 269‐270 274‐275 279‐280 284‐285 289‐290 294‐295 7 sites 299‐300 304‐305 309‐310 314‐315 319‐320 5 sites 324‐325 329‐330 334‐335 339‐340 344‐345 349‐350 354‐355 7 sites 406381 402040 397754 394066 390148 387276 383693 380224 376110 372983 370274 369047 369875 368841 367465 366081 364897 363775 362201 5682279 5684615 5687366 5691182 5694223 5698177 5700534 5702932 5703857 5706971 5709571 5713692 5718346 5722646 5726869 5731148 5735442 5739694 5743589 60 Effort (s) 786 854 839 818 754 775 728 5554 540 542 509 576 569 2736 717 743 726 686 702 637 547 4758 Total fish CPUE captured (fish/10 min)
6 4.58 8 5.62 11 7.87 5 3.67 7 5.57 2 1.55 1 0.82 40 Mean = 4.24
3 3.33 0 0.00 2 2.36 4 4.17 0 0.00 9 Mean = 1.92
0 0.00 0 0.00 0 0.00 1 0.87 0 0.00 0 0.00 0 0.00 1 Mean = 0.12
Appendix 1. Continued. Section Number and Name River km Easting Northing Effort (s) Total fish CPUE (fish/10 min)
(Section 3) Hwy 590 ‐ Tolman Bridge 359‐360 364‐365 369‐370 374‐375 379‐380 359770 361707 363722 367411 369054 5747402 5751268 5754644 5757113 5760911 517 570 788 603 484 2 1 1 0 4 2.32 1.05 0.76 0.00 4.96 384‐385 367016 5764822 584 0 0.00 Total 6 sites 3546 8 Mean = 1.51 (Section 2) Hwy 21 ‐ Hwy 590 389‐390 394‐395 399‐400 404‐405 409‐410 414‐415 419‐420 365045 362549 361075 361346 359783 359192 359161 5768633 5772562 5776828 5781462 5785541 5789610 5794000 736 687 747 696 592 732 747 7 4 12 6 2 4 2 5.71 3.49 9.64 5.17 2.03 3.28 1.61 424‐425 358116 5797576 816 1 0.74 Total 8 sites 5753 38 Mean = 3.96 (Section 1) Joffre Bridge ‐ Hwy 21 429‐430 434‐435 439‐440 444‐445 449‐450 454‐455 459‐460 464‐465 353795 349742 345779 346300 343421 339305 335366 330711 5798752 5798344 5797955 5793659 5791300 5791195 5790521 5790138 545 623 882 694 676 661 644 677 17 17 17 9 12 12 9 5 18.72 16.37 11.56 7.78 10.65 10.89 8.39 4.43 469‐470 326629 5792899 758 19 15.04 Total 9 sites 6160 117 Mean = 11.54
61 Appendix 2. Lower Red Deer Phase II sample season windows. 62 Appendix 2. Continued. 63 Appendix 2. Continued. 64 Appendix 3. Lower Red Deer River turbidity and water quality data used to conduct Phase II of the study on the river in 2004. Section Number and Name Section 1: Joffre Bridge to Hwy 21 Bridge Section 2: Hwy 21 (Content bridge) to Hwy 590 (McKenzie) crossing Section 3: Hwy 590 to Tolman Bridge Sample date 15‐Jun‐04 16‐Jun‐04 16‐Jun‐04 17‐Jun‐04 17‐Jun‐04 17‐Jun‐04 17‐Jun‐04 17‐Jun‐04 17‐Jun‐04 18‐Jun‐04 18‐Jun‐04 18‐Jun‐04 18‐Jun‐04 18‐Jun‐04 18‐Jun‐04 18‐Jun‐04 18‐Jun‐04 18‐Jun‐04 24‐Jun‐04 24‐Jun‐04 24‐Jun‐04 24‐Jun‐04 25‐Jun‐04 65 River km 439‐440 434‐435 429‐430 469‐470 464‐465 459‐460 454‐455 449‐450 444‐445 424‐425 419‐420 414‐415 409‐410 404‐405 399‐400 399‐400 394‐395 389‐390 384‐385 379‐380 374‐375 369‐370 364‐365 Visibility depth (m) 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 1.83 1.83 1.83 1.83 1.83 Water temp (oC) 14 18 18 Conductivity (μS) Appendix 3. Continued. Section Number and Name Section 4: Tolman Bridge to Bleriot Ferry Section 5: Bleriot Ferry to Drumheller Section 6: Drumheller to Dorothy Section 7: Dorothy to Finnegan Ferry Sample date 25‐Jun‐04 25‐Jun‐04 25‐Jun‐04 25‐Jun‐04 25‐Jun‐04 25‐Jun‐04 25‐Jun‐04 25‐Jun‐04 26‐Jun‐04 26‐Jun‐04 26‐Jun‐04 26‐Jun‐04 26‐Jun‐04 26‐Jun‐04 27‐Jun‐04 27‐Jun‐04 27‐Jun‐04 27‐Jun‐04 27‐Jun‐04 27‐Jun‐04 27‐Jun‐04 28‐Jun‐04 28‐Jun‐04 28‐Jun‐04 28‐Jun‐04 66 River km 359‐360 354‐355 349‐350 344‐345 339‐340 334‐335 329‐330 324‐325 319‐320 314‐315 309‐310 304‐305 299‐300 294‐295 289‐290 284‐285 279‐280 274‐275 269‐270 264‐265 259‐260 254‐255 249‐250 244‐245 239‐240 Visibility depth (m) 1.83 1.83 1.83 1.83 1.83 1.83 1.83 1.83 1.22 1.22 1.22 1.83 1.83 0.31 0.46 0.46 0.46 0.46 0.46 0.46 0.46 0.15 0.15 0.15 0.15 Water temp (oC) 18 Conductivity (μS) Appendix 3. Continued. Section Number and Name Section 8: Finnegan Ferry to Emerson Bridge Section 9: Emerson Bridge to Dinosaur PP Section 10: Dinosaur PP to Jenner Sample date 28‐Jun‐04 28‐Jun‐04 28‐Jun‐04 29‐Jun‐04 29‐Jun‐04 29‐Jun‐04 29‐Jun‐04 29‐Jun‐04 29‐Jun‐04 29‐Jun‐04 29‐Jun‐04 30‐Jun‐04 30‐Jun‐04 30‐Jun‐04 30‐Jun‐04 30‐Jun‐04 30‐Jun‐04 30‐Jun‐04 5‐Jul‐04 5‐Jul‐04 5‐Jul‐04 5‐Jul‐04 6‐Jul‐04 6‐Jul‐04 67 River km 234‐235 229‐230 224‐225 219‐220 214‐215 209‐210 204‐205 199‐200 194‐195 189‐190 184‐185 179‐180 174‐175 169‐170 164‐165 159‐160 154‐155 149‐150 144‐145 139‐140 134‐135 129‐130 124‐125 Visibility depth (m) 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0 0 0 0 0 0 Water temp (oC) 20 21 21 17 18 Conductivity (μS) 392 378 Appendix 3. Continued. Section Number and Name Section 11: Jenner to Buffalo Section 12: Buffalo to Bindloss Sectjon 13: Bindloss to AB ‐ SK border Section 3: Hwy 590 to Tolman Bridge Sample date 6‐Jul‐04 6‐Jul‐04 6‐Jul‐04 6‐Jul‐04 6‐Jul‐04 7‐Jul‐04 7‐Jul‐04 7‐Jul‐04 7‐Jul‐04 7‐Jul‐04 7‐Jul‐04 7‐Jul‐04 7‐Jul‐04 7‐Jul‐04 8‐Jul‐04 8‐Jul‐04 8‐Jul‐04 8‐Jul‐04 8‐Jul‐04 8‐Jul‐04 9‐Jul‐04 28‐Jul‐04 28‐Jul‐04 28‐Jul‐04 28‐Jul‐04 28‐Jul‐04 28‐Jul‐04 68 River km 119‐120 114‐115 109‐110 104‐105 99‐100 94‐95 89‐90 84‐85 79‐80 74‐75 69‐70 64‐65 59‐60 54‐55 49‐50 44‐45 39‐40 34‐35 29‐30 24‐25 29‐30 384‐385 379‐380 374‐375 369‐370 364‐365 359‐360 Visibility depth (m) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3.66 3.66 3.66 3.66 3.66 3.66 Water temp (oC) 20 16 17 Conductivity (μS) 378 381 367 Appendix 3. Continued. Section Number and Name Section 4: Tolman Bridge to Bleriot Ferry Section 5: Bleriot Ferry to Drumheller Section 6: Drumheller to Dorothy Sample date 28‐Jul‐04 28‐Jul‐04 28‐Jul‐04 28‐Jul‐04 28‐Jul‐04 29‐Jul‐04 29‐Jul‐04 29‐Jul‐04 29‐Jul‐04 29‐Jul‐04 29‐Jul‐04 29‐Jul‐04 29‐Jul‐04 69 River km 354‐355 349‐350 344‐345 339‐340 334‐335 329‐330 324‐325 319‐320 314‐315 309‐310 304‐305 299‐300 294‐295 Visibility depth (m) 3.66 3.66 3.66 3.66 3.66 3.66 3.66 3.66 3.66 3.66 3.66 3.66 3.66 Water temp (oC) 19 Conductivity (μS) Appendix 4. Comparison of species percent composition distributions by section between the 1990 ‐ 1991 assessment and initial sampling during the 2004 assessment on the Lower Red Deer River. Goldeye 1990-1991 Goldeye
50
2004 Goldeye
Percent of Goldeye
40
30
20
10
Section 13
Section 12
Section 11
Section 10
Section 9
Section 8
Section 7
Section 6
Section 5
Section 4
Section 3
Section 2
Section 1
0
Mooneye 1990-1991 Mooneye
100
2004 Mooneye
50
25
70 Section 13
Section 12
Section 11
Section 10
Section 9
Section 8
Section 7
Section 6
Section 5
Section 4
Section 3
Section 2
0
Section 1
Percent of Mooneye
75
71 Section 13
Section 13
Section 12
Section 11
Section 10
Section 9
Section 8
Section 7
Section 6
Section 5
Section 4
Section 3
Section 2
Section 1
Percent of Walleye
50
Section 12
50
Section 11
Section 10
Section 9
Section 8
Section 7
Section 6
Section 5
Section 4
Section 3
Section 2
Section 1
Percent of Sauger
Appendix 4. Continued. Walleye 1990-1991 Walleye
2004 Walleye
40
30
20
10
0
Sauger 1990-1991 Sauger
2004 Sauger
40
30
20
10
0
72 Section 13
Section 12
Section 11
Section 10
50
Section 9
Section 8
Section 7
Section 6
Section 5
Section 4
Section 3
Section 2
Section 1
Percent of Shorthead redhorse
Appendix 4. Continued. Shorthead Redhorse 1990-1991 Shorthead redhorse
2004 Shorthead redhorse
40
30
20
10
0
Appendix 5. Sauger age and length measurement relationships from the 1990 – 1991 and 2004 sport fish assessments on the Lower Red Deer River. Sauger age‐length relationships Fork Length (mm)
550
500
von Bertalanffy growth equation
Linf = 654 mm
k = 0.065
T0 = -6.519
450
400
350
300
250
200
150
100
Sauger, 1990-1991,N=115
y = 101.19Ln(x) + 186.51
R2 = 0.6088
50
0
0
Fork Length (mm)
550
500
1
2
3
4
5
6
Age (yrs)
7
8
9
10
11
von Bertalanffy growth equation
Linf = 509 mm
k = 0.196
T0 = -0.007
450
400
350
300
250
200
Sauger, 2004, N=59
150
100
y = 158.53Ln(x) + 65.862
R2 = 0.6075
50
0
0
1
2
3
4
5
6
Age (yrs)
73 7
8
9
10
11
Appendix 5. Continued. Sauger mean length‐at‐age relationships 500
450
Mean FL (mm)
400
350
300
250
RDR 2004, N=59
200
150
100
RDR 1990, N=115
50
0
1
2
3
4
5
6
7
8
9
10
11
Age (yrs)
500
450
Mean FL (mm)
400
350
300
250
BOW 1995 -1996, N=8
200
OLDMAN 1995 -1996, N=16
150
S.SASK 1995 -1996, N=96
100
RDR 2004, N=59
50
RDR 1990, N=115
0
1
2
3
4
5
6
Age (yrs)
74 7
8
9
10
11
Number of fish
Appendix 5. Continued. Sauger fork length frequency distributions 16
14
12
10
8
6
4
2
0
Sauger,1990-1991, N=115
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
16
Sauger, 2004, N=62
Number of fish
14
12
10
8
6
4
2
0
0
50
100
150
200
250
300
350
400
450
500
550
Fork length (mm)
75 600
650
700
750
800
850
900
950
1000
Appendix 5. Continued. Sauger age‐class profiles 50
Sauger, 1990, N=32
% Frequency
40
1985
30
1986
1983
20
1984
1987
10
1982
0
1
2
3
4
5
6
7
8
9
10
11
12
Age (yrs)
50
Sauger, 1991, N=83
% Frequency
40
30
1987
1986
20
1984
1983
1985
10
1988
1982
1981
0
1
2
3
4
5
6
7
8
9
10
11
12
Age (yrs)
Sauger, 2004, N=59
50
% Frequency
40
30
1998
20
1997
1999
1996
2000
1995
10
2001
1994
0
1
2
3
4
5
6
7
Age (yrs)
76 8
9
10
11
12
Walleye age and length measurement relationships from the 1990 – 1991 and 2004 sport fish assessments on the Lower Red Deer River. Walleye age‐length relationships Fork Length (mm)
Appendix 6. 800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
von Bertalanffy growth equation
No feasible solution
Walleye, 1990-1991,N=30
y = 189.51Ln(x) + 120.2
R2 = 0.8466
Fork Length (mm)
0
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
1
2
3
4
5
6
7
8
Age (yrs)
9
10
11
12
13
14
15
von Bertalanffy growth equation
Linf = 746 mm
k = 0.245
T0 = 1.534
Walleye ,2004, N=13
y = 333.22Ln(x) - 120.4
R2 = 0.9247
0
1
2
3
4
5
6
7
8
Age (yrs)
77 9
10
11
12
13
14
15
Appendix 6. Continued. Walleye mean length‐at‐age relationships 800
700
Mean FL (mm)
600
500
400
RDR 2004, N=13
300
200
RDR 1990, N=30
100
0
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Age (yrs)
900
800
Mean FL (mm)
700
600
500
BOW 1995 -1996, N=21
400
OLDMAN 1995 -1996, N=13
300
S.SASK 1995 -1996, N=75
200
RDR 2004, N=13
100
RDR 1990, N=30
0
0
1
2
3
4
5
6
7
8
9
Age (yrs)
78 10
11
12
13
14
15
16
Appendix 6. Continued. Walleye fork length frequency distributions Number of fish
10
Walleye, 1990-1991, N=30
8
6
4
2
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
Number of fish
10
Walleye, 2004, N=16
8
6
4
2
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
79 Appendix 6. Continued. Walleye age‐class profiles Walleye, 1990, N=17
50
% Frequency
40
1987 1986
30
1988
20
1984
10
1981
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Age (yrs)
Walleye, 1991, N=13
50
% Frequency
40
1990
30
1988
20
1987
1989
10
1984
1981
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Age (yrs)
50
Walleye, 2004, N=13
% Frequency
40
30
1996
20
2001 2000
1999 1998 1997
10
1995
1993
1990
0
1
2
3
4
5
6
7
8
Age (yrs)
80 9
10
11
12
13
14
Appendix 7. Goldeye age and length measurement relationships from the 1990 – 1991 and 2004 sport fish assessments on the Lower Red Deer River. Goldeye age‐length relationships 450
von Bertalanffy growth equation
No feasible solution
400
Fork Length (mm)
350
300
250
200
Goldeye, 1990-1991,N=319
y = 138.06Ln(x) + 121.05
R2 = 0.7285
150
100
50
0
0
1
2
3
4
5
Age (yrs)
6
7
8
9
10
450
von Bertalanffy growth equation
No feasible solution
400
Fork Length (mm)
350
300
250
200
150
Goldeye, 2004, N=165
100
y = 76.161Ln(x) + 184.34
R2 = 0.2099
50
0
0
1
2
3
4
5
Age (yrs)
81 6
7
8
9
10
Appendix 7. Continued. Goldeye mean length‐at‐age relationships 450
400
Mean FL (mm)
350
300
250
200
RDR 2004, N=165
150
100
RDR 1990, N=320
50
0
1
2
3
4
5
6
7
8
9
10
Age (yrs)
450
400
Mean FL (mm)
350
300
250
BOW 1995 -1996, N=4
200
OLDMAN 1995 -1996, N=5
150
S.SASK 1995 -1996, N=53
100
RDR 2004, N=165
50
RDR 1990, N=320
0
1
2
3
4
5
Age (yrs)
82 6
7
8
9
10
Number of fish
Appendix 7. Continued. Goldeye fork length frequency distributions Goldeye,1990-1991, N=694
90
80
70
60
50
40
30
20
10
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
Number of fish
Goldeye,2004, N=173
90
80
70
60
50
40
30
20
10
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
83 Appendix 7. Continued. Goldeye age‐class profiles 60
Goldeye, 1990, N=79
1986
% Frequency
50
40
30
1987
20
1985
10
1989
1988
1
2
1984
1983
6
7
0
3
4
5
8
9
10
11
12
Age (yrs)
50
Goldeye, 1991, N=240
1987
% Frequency
40
1986
30
1985
20
10
1984
1988
0
1
2
3
4
5
6
7
8
9
10
11
12
Age (yrs)
Goldeye,2004, N=165
50
1998
% Frequency
40
1999
30
1997
20
10
1996
2000
1995
0
1
2
3
4
5
6
7
8
9
10
11
12
Age (yrs)
84 Appendix 8. Mooneye age and length measurement relationships from the 1990 – 1991 and 2004 sport fish assessments on the Lower Red Deer River. Mooneye age‐length relationships 350
von Bertalanffy growth equation
No feasible solution
Fork Length (mm)
300
250
200
150
Mooneye, 1990-1991,N=22
y = 81.003Ln(x) + 132.65
R2 = 0.6154
100
50
0
0
1
2
3
4
5
Age (yrs)
6
7
8
9
10
350
von Bertalanffy growth equation
No feasible solution
Fork Length (mm)
300
250
200
150
Mooneye, 2004, N=25
100
y = 49.229Ln(x) + 177.56
R2 = 0.2361
50
0
0
1
2
3
4
5
Age (yrs)
85 6
7
8
9
10
Appendix 8. Continued. Mooneye mean length‐at‐age relationships
350
Mean FL (mm)
300
250
200
150
RDR 2004, N=25
100
50
RDR 1990, N=22
0
1
2
3
4
5
6
7
8
9
10
Age (yrs)
350
Mean FL (mm)
300
250
200
BOW 1995 -1996, N=35
150
OLDMAN 1995 -1996, N=30
S.SASK 1995 -1996, N=20
100
RDR 2004, N=25
50
RDR 1990, N=22
0
1
2
3
4
5
Age (yrs)
86 6
7
8
9
10
Appendix 8. Continued. Mooneye fork length frequency distributions Number of fish
10
Mooneye, 1990-1991, N=22
8
6
4
2
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
Mooneye, 2004, N=31
Number of fish
10
8
6
4
2
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
87 Appendix 8. Continued. Mooneye age‐class profiles 50
40
% Frequency
Mooneye, 1991, N=22
1987
1986
30
20
1985
10
1988
1984
0
1
2
3
4
5
6
7
8
9
10
11
12
Age (yrs)
50
1998
1997
40
% Frequency
Mooneye, 2004 N=25
30
20
1999
10
1995
0
1
2
3
4
5
6
7
Age (yrs)
88 8
9
10
11
12
Appendix 9. Fork length frequency distributions for other species from the sport fish assessment on the Lower Red Deer River in 2004. 10
Burbot, N=27
Number of fish
8
6
4
2
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
Shorthead Redhorse, N=35
10
Number of fish
8
6
4
2
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
10
White Sucker, N=17
Number of fish
8
6
4
2
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
Number of fish
10
Flathead Chub, N=32
8
6
4
2
0
0
50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000
Fork length (mm)
89 CONSERVATION
REPORT
SERIES
Alberta
Conservation Association
The The
Alberta
Conservation
Associationacknowledges
acknowledges
for their
their generous
support
of of
following
partner for
the the
following
partner
generous
support
this project
this project