RAINBOW TROUT SPAWNER SURVEYS

WEST ARM OF , 2014

FWCP PROJECT F-F15-19

Prepared for: Fish and Wildlife Compensation Program - Columbia 601 18th Street Castlegar, B.C., V1N 2N1

Prepared by: Masse Environmental Consultants Ltd 812 Vernon Street Nelson, BC, V1L 4G4

November 2014

Cover photo. Rainbow trout redds at Site RL35.2M, left (south) bank of Grohman Narrows, May 15, 2014. Rainbow Trout Spawner Surveys: West Arm of Kootenay Lake, 2014

EXECUTIVE SUMMARY

Rainbow trout spawner surveys were conducted in the West Arm of Kootenay Lake, from the Corra Linn Dam to Balfour, during April and May of 2014. A combination of low level helicopter surveys and boats surveys were used. The majority of spawning activity was observed in four general areas of the West Arm - Grohman Narrows, Nine Mile Narrows, Harrop Narrows, and Fraser Narrows/Balfour.

Over the course of the study, 809 redds were observed. Spawning activity was initially observed in Grohman Narrows on April 11th during boat surveys. Peak spawning activity occurred in the first week of May based on the increase in redds observed between consecutive surveys. Spawning activity had decreased by the end of May, a time when the elevation of the lake was rapidly rising due to increased runoff. During both aerial and boat surveys, both large ‘Gerrard’ size rainbow trout (~60-70 cm) and smaller, insectivorous, rainbow trout (~30-40 cm) were observed at spawning locations in the Fraser Narrows/Balfour area. Only insectivorous rainbow trout were observed at the other spawning locations.

Depth and water velocity were measured at major spawning areas soon after redds were first observed. The majority of redds occurred at depths between 1 and 4 m and where the water velocity at mid-column was between 0.4 and 0.8 m/s.

Low level helicopter surveys proved to be a suitable method of monitoring rainbow trout spawning activity in the West Arm. Individual redds could be clearly distinguished as light areas of substrate against a darker background. The exceptional water clarity of the West Arm allowed surveys to document redds at depths of up to 7 m. Continuing these surveys in future years is recommended as a means to monitor the population in the West Arm.

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ACKNOWLEDGEMENTS The following people assisted with field work and/or provided comments and background information that was incorporated into the report. Their assistance and input is appreciated.

Field Work: Jeremy Baxter (Mountain Waters Research) Clint Tarala Sean McTague Sylvie Masse Al Irvine Jennifer Ross Christine Nicol Mark Fjeld

Helicopter services: High Terrain Helicopters

Mapping and GIS services: Gary Pavan

BC Hydro Carol Lamont Dave Strajt

Marley Basset and Jeff Burrows (MFLNRO) provided temperature information for the West Arm of Kootenay Lake. FWCP provided a Marsh-McBirney flow meter for use during the project.

The project was funded by the Fish and Wildlife Compensation Program (FWCP) on behalf of its program partners BC Hydro, the Province of BC, Fisheries and Oceans Canada, First Nations and the public, who work together to conserve and enhance fish and wildlife impacted by the construction of BC Hydro dams.

Supplementary funding was provided by BC Hydro as part of the Grohman Narrows Channel Improvement project.

This report was prepared by:

Ico de Zwart, Ph.D., R.P.Bio. Masse Environmental Consultants Ltd 812 Vernon St, Nelson, BC, V1L 4G4

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TABLE OF CONTENTS Executive Summary ...... i Acknowledgements ...... ii Table of Contents ...... iii List of Figures ...... iv List of Photos ...... iv List of Tables ...... iv List of Appendices ...... iv 1 Introduction ...... 1 2 Goals and Objectives ...... 1 3 Study Area ...... 1 3.1 The West Arm of Kootenay Lake ...... 1 4 Methods ...... 3 4.1 Spawner and Redd Surveys ...... 3 4.1.1 Boat Surveys ...... 3 4.1.2 Aerial Surveys ...... 3 4.2 GIS and Mapping ...... 4 4.3 Lake Elevation and Water Temperature ...... 4 5 Results ...... 4 5.1 Overview ...... 4 5.2 Spawning Locations ...... 5 5.2.1 Grohman Narrows ...... 5 5.2.2 Nine Mile Narrows ...... 7 5.2.3 Harrop...... 7 5.2.4 Balfour ...... 9 5.3 Spawn Timing ...... 17 5.4 Habitat Attributes ...... 18 6 Discussion ...... 19 6.1 Abundance ...... 19 6.2 Spawn Timing ...... 20 6.3 Habitat Preference ...... 20 6.4 Habitat Availability ...... 21 6.5 Fisheries Management ...... 21

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7 Recommendations ...... 22 8 References ...... 23

LIST OF FIGURES Figure 1. Kootenay Lake and the West Arm study area...... 2 Figure 2. Overview of observed rainbow trout spawning locations in the West Arm of Kootenay Lake, 2014...... 10 Figure 3. Rainbow trout spawning locations in Grohman Narrows, May 2014...... 11 Figure 4. Rainbow trout spawning locations at , May 2014...... 12 Figure 5. Rainbow trout spawning locations in Nine Mile Narrows, May 2014...... 13 Figure 6. Rainbow trout spawning locations in the Harrop Narrows, May 2014...... 14 Figure 7. Rainbow trout spawning locations in Fraser Narrows, May 2014...... 15 Figure 8. Rainbow trout spawning locations at Balfour, May 2014...... 16 Figure 9. Kootenay Lake elevation during the study period...... 17 Figure 10. Water temperature in the West Arm of Kootenay Lake during the study period ...... 18 Figure 11. Redd depth frequency distribution...... 19 Figure 12. Redd water velocity frequency distribution...... 19

LIST OF PHOTOS Photo 1. Spawning area below Pacific Insight (RR35.2M), May 1, 2014...... 6 Photo 2. Spawning area downstream of Grohman Creek (RR36.9M), May 1, 2014...... 6 Photo 3. Spawning area on the Lasca Creek fan (RL55.8M), May 15, 2014...... 7 Photo 3. Spawning activity on right bank at Harrop Narrows (RR64.8M), May 15, 2014...... 8 Photo 4. Spawning area on left bank at Harrop Narrows (RL64.9M), May 15, 2014...... 8 Photo 6. Spawning area adjacent to Harlequin Island, Balfour (RL70.3M), April 23, 2014...... 9

LIST OF TABLES Table 1. Summary of surveys completed ...... 3 Table 2. Summary of aerial rainbow trout spawner counts in the West Arm of Kootenay Lake, 2014...... 5 Table 3. Summary of aerial rainbow trout redd counts in the West Arm of Kootenay Lake, 2014...... 5

LIST OF APPENDICES Appendix 1. Sample survey form. Appendix 2. Survey data

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1 INTRODUCTION Rainbow trout (Oncorhynchus mykiss) are a cold-water trout species that are considered an indicator species of ecosystem health and a popular target for recreational fishers. In Kootenay Lake, two distinct strains of rainbow trout are present - insectivorous rainbow trout and large piscivorous ‘Gerrard’ rainbow trout. Limited information is available regarding the status and habitat requirements of insectivorous rainbow trout in Kootenay Lake, despite the West Arm of Kootenay Lake once being considered one of the premier fly fish fisheries in (Andrusak 2006).

2 GOALS AND OBJECTIVES The objective of these rainbow trout spawner and redd surveys is to identify areas in the West Arm of Kootenay Lake where rainbow trout spawning occurs, and to enumerate rainbow trout redds and/or spawners. The goal of the project is to develop an index of rainbow trout abundance and to identify restoration or enhancement opportunities. The project addresses the following FWCP objectives that were identified in the large lakes action plan (FWCP 2013): 1) ensuring a diverse and productive aquatic ecosystem, and 2) maintaining or improving opportunities for sustainable use.

3 STUDY AREA 3.1 The West Arm of Kootenay Lake Kootenay Lake is a large fjord-like lake with a surface area of approximately 400 km2 that drains a watershed of almost 51,000 km2 (Figure 1). The West Arm of Kootenay Lake is one of the three arms of Kootenay Lake and is the outlet for the main body of the lake. The West Arm extends for approximately 35 km from Balfour downstream to the Grohman Narrows. An additional 10 km of the lower between Grohman Narrows and Corra Linn Dam is also included in the study area. The main body of the lake is comprised of the north and south arms. Most of the inflow into the lake is into the South Arm via the Kootenay River (Kootenai River in the USA). The Duncan River enters the North Arm and contributes ~ 10% of inflows.

The morphology of the West Arm is distinct from the main lake, and is best considered as a series of shallow basins connected by short narrow riverine sections (Daley et. al 1981). The West Arm is divided into upper and lower portions for fisheries management purposes. The Lower West Arm is the area between Corra Linn Dam and McDonalds Landing (Six Mile). The Upper West Arm is the area between McDonalds Landing and a line between Balfour Point and the Proctor Lighthouse at the outlet of the main body.

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Figure 1. Kootenay Lake and the West Arm study area.

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4 METHODS 4.1 Spawner and Redd Surveys 4.1.1 Boat Surveys Boat surveys were conducted between April 1 and May 20th, 2014 (Table 1). The purpose of the boat surveys were to: 1. identify potential spawning areas, largely based on the presence of suitable substrate, 2. determine the onset of spawning activity to inform when helicopter surveys could begin, 3. verify spawning in areas identified during aerial surveys where there was some uncertainty, 4. accurately georeference spawning locations 5. provide micro-habitat information on redds, such as water depth, velocity and substrate.

Water velocity and water depth was measured at a subset of redds within major spawning areas.

4.1.2 Aerial Surveys Aerial surveys of the entire West Arm were conducted at approximately weekly intervals from April 23 to May 30, 2014 (Table 1). Surveys were conducted on sunny days between 10:30 and 13:00 to ensure optimum viewing conditions. Elevation during the surveys ranged from 30 - 50 m above the water level. An experienced 2 person crew was used for enumeration, both viewing from the left side of the aircraft so it was clear they were viewing the same area. Using handheld counters, one crew member enumerated redds while the other enumerated spawners. Individual redds were easily distinguishable as light patches of gravel against a darker background. In areas with increased spawning activity, larger areas of gravels were often disturbed and individual redds were not discernible. In this case, the number of redds was estimated based on the size of the area disturbed and the area or size of a typical redd (~2 m²) in the lower Kootenay and lower Columbia River (Jeremy Baxter, Pers. Comm.). Redd and spawner data was recorded on standardized survey forms (Appendix 1).

Table 1. Summary of surveys completed

Date Aerial Boat Conditions Comment April 1 X Good Corra Linn – Nelson. April 2 X Good Nelson – Nine Mile April 11 X Good Grohman Narrows April 16 X Good Grohman Narrows April 23 X Excellent Entire West Arm April 26 X Good Grohman Narrows May 1 X Excellent Entire West Arm May 2 X Good Grohman Narrows and Balfour May 8 X Excellent Entire West Arm May 15 X Excellent Entire West Arm May 20 X Good Balfour May 30 X Good High water levels obscured early redds.

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4.2 GIS and Mapping Prior to conducting the surveys, the West Arm was delineated into 100 m segments using GIS. Each segment is named based on: 1) the distance from the confluence of the Kootenay River and the Columbia River (KM0.0); 2) bank location (RL – river left bank or RR – river right bank); and 3) channel location (M – mainstem or S – side channel). Similar naming conventions are used on the Columbia River, lower Kootenay River, and Duncan River, and are designed to provide unambiguous site names. During the aerial surveys, each spawning location was also given a named based on its location that would be easier to remember. For example, ‘power lines Balfour’ (RL69.4M) is located below the power line crossing of the West Arm near Balfour.

Aerial imagery of the West Arm was provided by BC Hydro.

4.3 Lake Elevation and Water Temperature Lake elevation during the surveys was obtained from BC Hydro. Lake elevation is measured at three locations on the West Arm - Corra Linn, Nelson and at Queen’s Bay.

Water temperature data for the West Arm was obtained from the Ministry of Forest, Lands and Natural Resources Operations, who maintain a temperature logger in Balfour (M. Basset pers. comm.).

5 RESULTS 5.1 Overview Aerial surveys provided an effective and efficient means of enumerating rainbow trout spawners and redds in the West Arm. The entire West Arm from Corra Linn to Balfour could be surveyed in less than two hours. Weather conditions were favorable for most of the time when aerial surveys were conducted. Flights where scheduled at weekly intervals and the first four flights coincided with calm, sunny days. Viewing conditions were excellent for these flights, and all redds were readily distinguishable. The fifth flight was delayed by a week due to poor weather. Although viewing conditions on this survey (May 30th) were excellent, rising water levels in the West Arm obscured many of the redds that had been observed on previous flights. As a result, this survey only reported new or shallow redds for a reduced number of locations (Appendix 2).

Redds were readily distinguishable from undisturbed substrate and the survey crew was able to distinguish redds up to 7 m in depth provided light conditions were favorable. Individual fish could also be identified in shallower (< 5 m) areas. Very little redd fading occurred during this period based on the continued ability to observe several redds that were initially marked on April 16th using a large nut with flagging. Rainbow trout redd life is approximately 30 days in the lower Kootenay and lower Columbia rivers (Jeremy Baxter, Pers. Comm.).

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Aerial spawner and redd counts in the West Arm are summarized in Table 2 and Table 3. The full data is provided in Appendix 2. The peak spawner count of 324 fish occurred on May 8th. The peak redd count occurred on May 15th, when 711 redds were observed. An estimated 98 new redds were observed on the May 30th flight, bringing the total number of redds observed to 809.

Table 2. Summary of aerial rainbow trout spawner counts in the West Arm of Kootenay Lake, 2014.

Location April 23 May 1 May 8 May 15 May 30a Grohman 22 67 111 131 14 Lasca 0 12 12 25 40 Harrop 0 18 38 52 26 Balfour 0 28 163 55 15 Total 22 125 324 263 95

Table 3. Summary of aerial rainbow trout redd counts in the West Arm of Kootenay Lake, 2014.

Location April 23 May 1 May 8 May 15 May 30a Grohman 31 117 240 299 30 Lasca 0 18 38 80 12 Harrop 14 45 107 175 34 Balfour 5 135 227 157 22 Total 50 315 612 711 98 a only new redds recorded as earlier redds obscured.

5.2 Spawning Locations Spawning activity was observed in four general areas in the West Arm – Grohman Narrows, Nine Mile Narrows, Harrop Narrows, and Fraser Narrows/Balfour (Figure 2). These locations are all where the West Arm narrows.

We also incidentally recorded spawning activity on the Kootenay River below Corra Linn dam on the April 23 and May 1 flights. Forty redds and 19 fish were observed on May 1, 2014. This part of the Kootenay River is isolated from the remainder of the Kootenay River by the Corra Linn Dam (upstream) and Upper Bonnington Dam (downstream). The locations of these redds are provided in Appendix 2.

5.2.1 Grohman Narrows Three major spawning areas (> 40 redds) were observed in the Grohman Narrows (Figure 3). These were on the left bank below Pacific Insight (RL35.2M) (Photo 1), on the left bank adjacent to the island (RL36.6S), and on the right bank downstream of Grohman Creek (RR36.9M) (Photo 2). Several smaller

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Photo 1. Spawning area below Pacific Insight (RR35.2M), May 1, 2014.

Photo 2. Spawning area downstream of Grohman Creek (RR36.9M), May 1, 2014. areas were also observed, notably at the mouth of Grohman Creek, at the downstream end of the island, and upstream of the Hwy 3 bridge at Taghum (Figure 4). Limited spawning activity was observed around the bar complex on the right bank (RR35.7M – RR36.0M) despite the area having abundant gravels. This

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was attributed to the limited flow through this area during the spawning period. Spawning was also observed in the lower Kootenay River near Beasley (Figure 2) and near Taghum (Figure 4).

5.2.2 Nine Mile Narrows One major spawning area (RL55.8M) was observed in the Nine Mile Narrows, on the Lasca Creek fan downstream and adjacent to the navigation beacon (Figure 5). Spawning was initially observed on the edge of the fan near the drop off. As water levels rose, additional spawning occurred in shallow areas (Photo 3). A peak count of 80 redds was observed.

Photo 3. Spawning area on the Lasca Creek fan (RL55.8M), May 15, 2014.

5.2.3 Harrop Large spawning areas were observed on both sides of the Harrop Narrows, approximately 300 m upstream of the ferry crossing (Figure 6). Most redds (~ 2/3) were observed on the right bank (RR64.8M, Photo 4), the remainder were observed on the Harrop Creek fan (RL64.9M, Photo 5). A peak count of 175 redds was observed.

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Photo 4. Spawning activity on right bank at Harrop Narrows (RR64.8M), May 15, 2014.

Photo 5. Spawning area on left bank at Harrop Narrows (RL64.9M), May 15, 2014.

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5.2.4 Balfour Three major spawning areas were observed near Balfour. The majority of spawning occurred near the upstream end of the small island (Harlequin Island) upstream of Fraser Narrows (RL70.3M) and on the right bank adjacent to this (RR70.4M) (Figure 7). The third major spawning area was on the right bank at the inlet to West Arm (RR72.8M) (Figure 8). Spawning was also observed on both sides near the upstream end of Fraser Narrows (RL69.4M, RR69.7M), on the right bank on the downstream end of Fraser Narrows (RR68.3), as well as several locations along the right bank at Balfour.

Of note, several large ‘Gerrard’ size rainbow trout were observed in several of these areas from the helicopter on consecutive flights. Boat surveys on May 2 and May 20th confirmed the presence of large (~ 60-70 cm) rainbow trout and regular (30-40 cm) rainbow trout on spawning grounds at the inlet to the West Arm and near Balfour.

Photo 6. Spawning area adjacent to Harlequin Island, Balfour (RL70.3M), April 23, 2014.

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Figure 2. Overview of observed rainbow trout spawning locations in the West Arm of Kootenay Lake, 2014.

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Figure 3. Rainbow trout spawning locations in Grohman Narrows, May 2014.

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Figure 4. Rainbow trout spawning locations at Taghum, May 2014.

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Figure 5. Rainbow trout spawning locations in Nine Mile Narrows, May 2014.

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Figure 6. Rainbow trout spawning locations in the Harrop Narrows, May 2014.

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Figure 7. Rainbow trout spawning locations in Fraser Narrows, May 2014.

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Figure 8. Rainbow trout spawning locations at Balfour, May 2014.

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5.3 Spawn Timing Spawning was first observed in Grohman Narrows during boat surveys on April 11th. Although these initial boat surveys focused on Grohman Narrows, the first aerial survey recorded few redds in other areas of the West Arm, indicating that this is representative of the start of spawning. The peak spawner count was observed on May 8th. The largest increase in redds (297 new redds) occurred between May 1st and May 8th indicating that peak of spawning occurred during this week. The peak redd count was recorded on May 15th, although spawning activity continued after this date since new redds were observed on the last survey conducted on May 30th. Spawn timing was similar for all locations in the West Arm.

The elevation of Kootenay Lake during the survey period is provided in Figure 9. Data is shown for Queens Bay, at the entrance to the West Arm, and for Nelson. The timing of the aerial surveys and the cumulative redd count are also shown. Over the course of the surveys, water depth increased by 1.76 m at Queens Bay and 1.56 at Nelson, with most of the increase in elevation occurred between the fourth and fifth surveys.

534 1000 Queens Bay Nelson Redd Count

533 750

532 500 Elevation (m) Redds (CumulativeRedds Total)

531 250

530 0 3 Apr 1 May 8 May 10 Apr 17 Apr 24 Apr 15 May 22 May 29 May Date

Figure 9. Kootenay Lake elevation during the study period (data from BC Hydro). The vertical dashed lines denote the timing of aerial surveys. The cumulative redd count is shown.

Water temperature for the West Arm of Kootenay Lake (at Balfour) during the study period is provided in Figure 10. Redds were first observed on April 11th when the daily average water temperature was 5.2°C.

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The majority of spawning occurred between April 24 and May 8, which is when the daily average water temperature began to consistently increase above 5°C. The date when water temperatures reach 5°C is considered a predictor of when rainbow trout spawning begins in many systems (McPhail 2007).

10 1000 Temperature Redd Count

8 750

6 C) o

500

4 Temperature ( Redds (CumulativeRedds Total)

250 2

0 0 3 Apr 1 May 8 May 10 Apr 17 Apr 24 Apr 15 May 22 May 29 May Date

Figure 10. Daily average water temperature in the West Arm of Kootenay Lake during the study period (data from MFLNRO). The vertical dashed lines denote the timing of aerial surveys. The cumulative redd count is shown.

5.4 Habitat Attributes Depth and velocity measurements were collected at subset of redds within major spawning areas. The data was collected soon after the redds were initially observed. Redds depths ranged from ~ 1.0 m to over 10 m, with most occurring at depths between 1 – 4 m (Figure 11). Mid-column water velocity ranged from 0.35 – 1.2 m/s, with the majority ranging from 0. 4 – 0.8 m/s (Figure 12). Redds were all located in areas of laminar flow and very little difference in water velocity was observed between the bottom to the top of the water column.

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6

5

4

3 Frequency

2

1

0 0-1 1-2 2-3 3-4 4-5 5-6 6-7 7+ Depth Increment (m)

Figure 11. Redd depth frequency distribution.

7

6

5

4 Frequency 3

2

1

0 > 0.2 0.2 - 0.4 0.4 - 0.6 0.6 - 0.8 0.8 - 1.0 1.0 - 1.2 > 1.2 Velcoity Increment (m)

Figure 12. Redd water velocity frequency distribution.

6 DISCUSSION 6.1 Abundance Rainbow trout spawner and redd counts provide an index of abundance that can be used to monitor this population. Although peak counts are often used as a simple metric, they may be unreliable. The peak count may not occur on the day a survey was conducted, leading to an underestimate. Alternatively, in

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some years, the spawning period may be temporally compressed, resulting in inflated counts relative to years when spawning occurs over a longer period.

A variety of methods can be used to estimate total spawner escapement using count data. The simplest method is to multiply the peak count by an expansion factor to estimate total escapement. The expansion factor is typically developed based on studies where information is available on both total escapement and count data.

Area under the curve (AUC) methods can also be used to estimate the number of fish on days when surveys were not conducted by extrapolating between survey dates. This provides a measurement of the number of fish for each day and allows a total number of fish days to be estimated over the spawning period. If information on residence time, the average time a fish spends in the spawning area is known, the total escapement can be estimated.

The total redd count would seem to be a simple method of estimating total escapement using the assumption that each redd requires two fish. However, this is unreliable since some fish construct more than one redd, redd superimposition can occur where multiple redds overlap, and, if redd fading occurs during the study period it is difficult from the air to obtain a total count. For example, in this study, rising water levels at the end of May opened up additional habitat spawning but also obscured many older redds. As redds have a long residence time, distinguishing between new and old redds can be difficult.

6.2 Spawn Timing Spawn timing in the West Arm is comparable to rainbow trout spawn timing in nearby systems. Annual rainbow trout spawner surveys are conducted on the Columbia River below Hugh L. Keenleyside Dam and in the lower Kootenay River below , and on the Lardeau River at Gerrard. In 2014, peak spawning occurred on May 7th in the Columbia River, April 28th on the Kootenay River (J. Baxter, pers comm.), and May 6th on the Lardeau River. For all of these systems, peak spawning typically occurs in the last week of April or the first half of May, depending on the year.

6.3 Habitat Preference Water depths and velocities measured at redds in the West Arm are similar to other systems. In the Columbia River, detailed habitat measurements were collected on redds < 1.5 m deep (Thorley & Baxter 2012). A minimum depth of 0.5 m was required and depths greater than 0.8 m were preferred. Redds are also observed at depths > 1.5 m in the Columbia River but habitat measurements on these redds were not collected. Water velocities between 0.4-0.9 m/s were selected. Similar preferences have been documented for Gerrard rainbow trout spawning in the Duncan River below the (Thorley et. al 2011) and in the Lardeau River at Gerrard (Thorley and Bowers 2006). Water depths of 0.25–2.5 m and water velocities from 0.3-0.9 m/s are also reported in the literature (McPhail 2007).

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6.4 Habitat Availability Spawning habitat in the West Arm is restricted to the narrows, where increased water velocity occurs during the spawning period. In these areas spawning habitat does not appear to be limiting, since the amount of redd superimposition was limited. In areas where spawning habitat is limited relative to the number of spawners, a high degree of superimposition is expected.

Spawning has also been reported in tributaries to the West Arm, although no survey data is available. We assessed the fans and/or the lower reaches of all tributaries to the West Arm from the Corra Linn Dam to Nine Mile Narrows in early April when Kootenay Lake was near its minimum elevation. Spawning habitat in all these tributaries was very limited. Based on our observations during this study, spawning in tributaries is expected to constitute only a small fraction of the spawning activity in the West Arm for the following reasons: 1. Tributaries to the West Arm only contain a small amount of the spawning habitat compared to what is available in the West Arm. 2. Water temperatures are colder in tributaries and spawning would be delayed compared to the West Arm. 3. When water temperatures become suitable for spawning, stream flows in tributaries are typically highly variable and streams contain elevated levels of suspended solids. In comparison, the West Arm provides consistent, stable, habitat with very low levels of suspended solids throughout the spawning and incubations period.

6.5 Fisheries Management Spawner and redd counts provide a useful tool for fisheries management purposes as they provide a metric that can be used to monitor abundance. The West Arm is divided into two areas for fisheries management purposes. Grohman Narrows is located in the Lower West Arm, and the remaining major spawning areas are located in the Upper West Arm. The current regulations allow for up to 5 rainbow trout per day to be caught. The Upper West Arm requires release between Jan 1 – May 31, but no restriction is in place on the Lower West Arm.

Angler effort in 2006 was estimated to be < 10% of the effort in the 1970’s, suggesting a relatively large decline in the population had occurred (Andrusak 2006). During our surveys, we occasionally observed boats moored on or adjacent to spawning areas, suggesting anglers are specifically targeting these areas during the spawning period. Although there is no evidence at this stage to indicate that fishing pressure on spawning grounds is affecting the population, if this is the case then encouraging anglers to avoid spawning areas during the spawning period may be a useful management tool. Although we have limited information on the total rainbow trout escapement in the West Arm, and no information on trends over time, the observation of 809 redds suggests that the population is relatively small.

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7 RECOMMENDATIONS 1. Annual aerial spawner surveys are recommended as a cost effective means of monitoring this population. At a minimum 3 flights at weekly intervals beginning late April or early May is recommended, although additional flights would be preferred if spawn timing varies between years. Flights should occur between 10 and 1 pm on sunny days to ensure optimum viewing. Approximately 1.5 - 2 hours of helicopter time is required per flight to survey from Corra Linn Dam to Balfour.

2. Conduct additional surveys at Balfour to determine the extent of spawning by Gerrard-size rainbow trout in this area. This could include snorkel surveys to obtain a more accurate count of Gerrard-size rainbow trout, and angling to verify spawning. Samples for genetic analysis could be obtained to determine whether these rainbow trout are distinct from those that spawn in the Lardeau River and the Duncan River.

3. Develop a communication and outreach program to inform anglers of areas of known spawning and encourage avoiding these areas from April to May to avoid disturbing spawning fish.

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8 REFERENCES Andrusak, G.F. 2006. West Arm Kootenay Lake rainbow trout stock status and their recreational fishing potential. Report prepared for the Habitat Conservation Trust Fund. Reported prepared by Redfish Consulting.

Daley, R.J., E.C. Carmack, C.B.J. Gray, S. Jasper, C.H. Pharo and R.C. Weigand. 1981 The effects of upstream impoundments on the limnology of Kootenay Lake, B.C. Environment Canada, Scientific Report Series No' 117' 98pp.

FWCP (Fish and Wildlife Compensation Program) 2012. Columbia Basin large lakes action plan. Draft. June 2012.

McPhail, J.D (2007). The freshwater fishes of British Columbia. University of Alberta Press, Edmonton, AB.

Thorley, J.L. and J.T.A. Baxter 2012. WLR Monitoring Study No. CLBMON-46 (Year 4) Lower Columbia River Rainbow Trout Spawning Assessment 2011. Columbia River Water Use Plan. BC Hydro, Castlegar. Mountain Water Research and Poisson Consulting Ltd.

Thorley, J.L., Irvine, R.I., Baxter, J.T.A., Hagen, J. and Porto, L. (2011) Lower Duncan River habitat use monitoring (Year 2). Duncan Dam Project Water Use Plan VE51873-2010. BC Hydro, Castlegar, BC.

Thorley, J. L. and J. Bowers 2006. Gerrard rainbow spawning habitat assessment: water depth and velocity over the main spawning gravels on the Lardeau River during low flows. Prepared for Ministry of Environment, Nelson, BC.

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APPENDIX 1

EXAMPLE SURVEY FORM

Rainbow Trout Spawning Survey Field Sheet

MOUNTAIN WATER RESEARCH Survey Type: ⃝ Boat ⃝ Heli DATE: CREW: CONDITIONS: Marker Depth Kootenay Rainbow Trout Spawner Survey REDDS FISH WPT Velocity COMMENTS # (m) KOR033.80 RUB Above Taghum Bridge KOR033.80 LUB Above Taghum Bridge (mid) KOR035.20 RUB at Insight KOR036.40 Grohman Island Point RUB KOR036.45 RUB Grohman Island KOR036.65 RUB Grohman Island Top Ch. KOR037.00 LUB d/s Grohman Creek KOR038.25 Grohman Docks KOR055.60 Nine Mile Narrows KOR064.90 RUB Proctor KOR064.90 LUB Harrop KOR068.35 LUB Balfour Narrows KOR069.30 RUB Power lines Balfour KOR069.75 LUB Near Bay KOR070.40 RUB Balfour Island Head End KOR072.25 upstream of Balfour Docks KOR072.65 RUB Last Dock (Sailboats) KOR072.85 LUB upstream of light beacon

Marker Depth Kootenay River - Downstream Corra Lynn REDDS FISH WPT Velocity COMMENTS # (m) KOR024.90 Mid Channel Between Islands KOR025.10 RUB Bank Downstream Dam

ADDITIONAL COMMENTS:

APPENDIX 2

SURVEY DATA

Redd count data in the West Arm of Kootenay Lake, April/May 2014.

Name RiverSIte River Km LUB/RUB Easting Northing 23‐Apr‐14 1‐May‐14 8‐May‐14 15‐May‐14 30‐May‐14 Comments Beasley u/s island RL028.2M 28.2 RUB 467683 5481441 7 Beasley RL028.9M 28.9 RUB 468321 5481271 10 Taghum old bridge RR032.7M 32.7 LUB 471788 5481907 4 above Taghum bridge RR034.0M 34 LUB 472569 5482755 23 13 above Taghum bridge (mid) RL034.1M 34.1 RUB 472759 5482720 2 21 0 at Insight RL035.2M 35.2 RUB 473704 5483075 22 54 78 86 Island complex RR035.7M 35.7 LUB 474261 5483120 7 Island complex RR035.8M 35.8 LUB 474309 5483038 7 Island complex RR035.9M 35.9 LUB 474464 5483137 2 Island complex RR036.0M 36 LUB 474579 5483096 4 Grohman Bluffs RR036.2M 36.2 LUB 474676 5483084 4 Grohman Island Point RL036.3M 36.3 RUB 474821 5482858 1 5 5 13 Grohman Island RL036.4S 36.4 RUB 474867 5482721 2 4 4 Grohman Island top channel RL036.6S 36.6 RUB 474979 5482712 8 16 39 51 Outfall below Grohman Creek RR036.9M 36.9 LUB 475346 5482822 15 64 73 d/s Grohman Creek RR037.1M 37.1 LUB 475493 5482647 12 35 u/s Grohman Creek RR037.3M 37.3 LUB 475660 5482579 13 13 Nine Mile Narrows RL055.8M 55.8 RUB 488074 5494019 18 38 80 35 estimate 65% are old redds Redfish RR064.8M 64.8 LUB 496383 5495272 4 28 68 120 60 estimate 65% are old redds Harrop RL064.9M 64.9 RUB 496533 5495182 10 17 39 55 36 estimate 65% are old redds d/s Fraser Narrows RR068.3M 68.3 LUB 499796 5495960 14 8 15 d/s Fraser Narrows RR068.3M 68.3 LUB 499774 5495965 40 power lines Balfour RL069.4M 69.4 RUB 500875 5496118 20 26 19 4 Near Bay RR069.7M 69.7 LUB 501112 5496337 6 24 9 3 Balfour Island head end RL070.3M 70.3 RUB 501740 5496323 5 48 79 34 70.4 ‐ 70.65 RR070.4M 70.4 LUB 501861 5496524 2 87 74 docks RR070.9M 70.90 LUB 502262 5496638 4 near ramp RR071.1M 71.10 LUB 502453 5496687 6 last dock (sailboats) RR072.2M 72.2 LUB 503538 5496799 3 5 3 mid island RR072.3M 72.3 LUB 503662 5496812 3 upstream Balfour docks RR072.8M 72.8 LUB 503996 5497043 2 3

Notes: River Km measured from the confluence of the Kootenay River and Columbia River LUB ‐ left upstream bank; RUB ‐ right upstream bank (as viewed from the helicopter) Rainbow trout count data in the West Arm of Kootenay Lake, April/May 2014.

Name RiverSIte River Km LUB/RUB Easting Northing 23‐Apr‐14 1‐May‐14 8‐May‐14 15‐May‐14 30‐May‐14 Comments Beasley u/s island RL028.2M 28.2 RUB 467683 5481441 Beasley RL028.9M 28.9 RUB 468321 5481271 5 Taghum old bridge RR032.7M 32.7 LUB 471788 5481907 4 above Taghum bridge RR034.0M 34 LUB 472569 5482755 20 above Taghum bridge (mid) RL034.1M 34.1 RUB 472759 5482720 6 at Insight RL035.2M 35.2 RUB 473704 5483075 12 22 55 34 Island complex RR035.7M 35.7 LUB 474261 5483120 5 Island complex RR035.8M 35.8 LUB 474309 5483038 Island complex RR035.9M 35.9 LUB 474464 5483137 Island complex RR036.0M 36 LUB 474579 5483096 Grohman Bluffs RR036.2M 36.2 LUB 474676 5483084 2 Grohman Island Point RL036.3M 36.3 RUB 474821 5482858 6 10 Grohman Island RL036.4S 36.4 RUB 474867 5482721 Grohman Island top channel RL036.6S 36.6 RUB 474979 5482712 10 10 14 21 Outfall below Grohman Creek RR036.9M 36.9 LUB 475346 5482822 9 21 26 d/s Grohman Creek RR037.1M 37.1 LUB 475493 5482647 13 30 u/s Grohman Creek RR037.3M 37.3 LUB 475660 5482579 10 Nine Mile Narrows RL055.8M 55.8 RUB 488074 5494019 12 12 25 40 Redfish RR064.8M 64.8 LUB 496383 5495272 12 26 27 20 Harrop RL064.9M 64.9 RUB 496533 5495182 6 12 25 6 d/s Fraser Narrows RR068.3M 68.3 LUB 499796 5495960 4 15 Large fish observed May 1 ‐ sturgeon? d/s Fraser Narrows RR068.3M 68.3 LUB 499774 5495965 Large fish observed May 1 ‐ sturgeon? power lines Balfour RL069.4M 69.4 RUB 500875 5496118 18 20 5 Gerrard size fish Near Bay RR069.7M 69.7 LUB 501112 5496337 20 Gerrard size fish Balfour Island head end RL070.3M 70.3 RUB 501740 5496323 35 Gerrard size fish 70.4 ‐ 70.65 RR070.4M 70.4 LUB 501861 5496524 2 25 Gerrard size fish docks RR070.9M 70.90 LUB 502262 5496638 near ramp RR071.1M 71.10 LUB 502453 5496687 last dock (sailboats) RR072.2M 72.2 LUB 503538 5496799 2 5 mid island RR072.3M 72.3 LUB 503662 5496812 4 Gerrard size fish upstream Balfour docks RR072.8M 72.8 LUB 503996 5497043 2 54 50 Gerrard size fish

Notes: River Km measured from the confluence of the Kootenay River and Columbia River LUB ‐ left upstream bank; RUB ‐ right upstream bank (as viewed from the helicopter) Depth and velocity measurements for selected spawning locations ‐ West Arm of Kotoenay Lake, 2014

Name RiverSite River Km Date Depth (m) Velocity (m/s) Comments above Taghum bridge (mid) RR034.0M 34.0 02‐May‐14 9 to 11 general depth in area ‐ no redds visible from boat above Taghum bridge RL034.1M 34.1 02‐May‐14 7 to 8 0.95 gravels and cobbles at Insight RL035.2M 35.2 02‐May‐14 2 to 3.5 0.8 gravels. Area of laminar flow Grohman Island Point RL036.3M 36.3 02‐May‐14 3 0.48 superimposed, sands/gravel Grohman Island RL036.4S 36.4 02‐May‐14 2.5 0.4 Grohman Island top channel RL036.6S 36.6 02‐May‐14 2.8 0.4 gravels Outfall below Grohman Creek RR036.9M 36.9 02‐May‐14 2.2 1.2 along bank, some superimposed d/s Grohman Creek RR037.1M 37.1 15‐May‐14 2.6 0.35 u/s Grohman Creek RR037.3M 37.3 15‐May‐14 0.8 0.55 u/s Grohman Creek RR037.3M 37.3 15‐May‐14 1.1 0.7 u/s Grohman Creek RR037.3M 37.3 15‐May‐14 1.8 1.1 Nine Mile Narrows RL055.8M 55.8 02‐May‐14 4.6 0.7 Redfish RR064.8M 64.8 02‐May‐14 3.9 0.55 Harrop RL064.9M 64.9 02‐May‐14 1.3 0.7 plus more at up to 4 m depth d/s Fraser Narrows RR068.3M 68.3 02‐May‐14 5.7 lots of whitefish observed (video) power lines Balfour RL069.4M 69.4 02‐May‐14 2.1 0.55 1 large RB (60+ cm) Balfour Island head end RL070.3M 70.3 02‐May‐14 3 0.8 saw several large fish, gravels with occasional boulder