Columbia River Project Water Use Plan Columbia White ... · 4/30/2013 · Columbia River Project...

April 30, 2013

Columbia River Project Water Use Plan Columbia White Sturgeon Management Plan Mid Columbia River Sturgeon Egg Mat Monitoring and

Underwater Videography Feasibility Implementation Year 6

Reference: CLBMON-23 White Sturgeon Spawning Monitoring: 2012 Investigations

Study Period: July – September 2012

Louise Porto MSc., R.P.Bio. Christin Davis BSc. Crystal Lawrence BSc., R.P.Bio.

AMEC Environment & Infrastructure Suite 601E, 601 Front St., Nelson, BC V1L 4B6

amec.com VE52241-2012

Middle Columbia River White Sturgeon Spawning Monitoring CLBMON-23 Year 6 Data Report (2012)

Submitted to: BC Hydro Submitted by: AMEC Environment & Infrastructure Nelson, BC April 2013

http://www.bchydro.com/�

AMEC Environment & Infrastructure a division of AMEC Americas Limited Suite 601E, 601 Front St. Nelson, BC Canada V1L 4B6 Tel +1 (250) 354-1600 Fax +1 (250) 354-1677 www.amec.com

Middle Columbia River White Sturgeon Spawning Monitoring

Year 6 Data Report - 2012

Submitted to:

BC Hydro

Castlegar, British Columbia

Submitted by:

AMEC Environment & Infrastructure a division of AMEC Americas Limited

Nelson, BC

Submitted:

30 April 2013

AMEC File: VE52241-2012

BC Hydro – CLBMON-23 Mid-Columbia River White Sturgeon Spawning Monitoring April 2013

AMEC File: VE52241-2012 Page i

Recommended Citation: AMEC. 2013. Middle Columbia River White Sturgeon Spawning Monitoring (CLBMON-23). Year 6 Data Report. Report Prepared for: BC Hydro, Castlegar. Prepared by: AMEC Environment & Infrastructure Ltd. 23 pp + 3 App. Key Words: Middle Columbia River, White Sturgeon, Spawning, Eggs, Free Embryos, Revelstoke Dam


AMEC File: VE52241-2012 Page ii

TABLE OF CONTENTS

Page

Acknowledgements…………………………………………………………………………………v Executive Summary…………………………………………………………………………………vi

1.0 INTRODUCTION ............................................................................................................... 1 1.1 Objectives ................................................................................................................. 2 1.2 Purpose .................................................................................................................... 2

2.0 METHODS ........................................................................................................................ 4 2.1 Study Area ................................................................................................................ 4 2.2 Environmental Parameters ........................................................................................ 4 2.3 Sample Timing .......................................................................................................... 4 2.4 Spawn Monitoring ..................................................................................................... 5

2.4.1 Egg Collection Mats ...................................................................................... 5 2.4.2 D-Ring Larval Drift Nets ................................................................................. 8

2.5 Egg Incubation .......................................................................................................... 9 2.6 Egg Stranding ........................................................................................................... 9 2.7 Preservation, Staging & Spawn Timing Estimation .................................................... 9

3.0 RESULTS ........................................................................................................................ 10 3.1 Environmental Parameters – Discharge, Water Temperature & Elevation .............. 10 3.2 White Sturgeon Egg & Free Embryo Collection ....................................................... 13

3.2.1 Egg Collection Mats .................................................................................... 13 3.2.2 Drift Nets ..................................................................................................... 13

3.3 Staging & Estimated Spawn Timing ........................................................................ 14 3.4 White Sturgeon Spawning and Physical Parameters .............................................. 15

4.0 DISCUSSION .................................................................................................................. 17 4.1 Management Question 1: Where are the primary White Sturgeon incubation sites

below Revelstoke Dam? ......................................................................................... 17 4.2 Management Question 2: How do dam and reservoir operations affect egg and larval

survival in this area? Specifically, do significant numbers of eggs become dewatered as a result of operations? ....................................................................................... 17

4.3 Management Question 4: What is the most effective method for monitoring spawning of White Sturgeon? ................................................................................................ 18

4.4 Management Question 5: Can modifications be made to operations of Revelstoke Dam and ALR to protect or enhance White Sturgeon incubation habitat? .............. 18

5.0 ASSESSMENT OF METHODS ....................................................................................... 20

6.0 RECOMMENDATIONS ................................................................................................... 21

7.0 REFERENCES ................................................................................................................ 22


AMEC File: VE52241-2012 Page iii

Lis t of Figures

Figure 1: Overview of the middle Columbia River, which includes the Upper and Lower Arrow lakes, depicting Revelstoke and Hugh L. Keenleyside dams. ..................................... 3

Figure 2: Study area and sample site locations for Middle Columbia River White Sturgeon spawn monitoring below Revelstoke Dam, 2012. ....................................................... 7

Figure 3: Hourly total discharge (m3/s) from Revelstoke Dam (REV) and hourly water level elevation (meters above sea level) of Arrow Lakes Reservoir (ALR) as measured in Nakusp, BC, April 1 to September 30, 2012. ............................................................ 10

Figure 4: Hourly total discharge (m3/s) from Revelstoke Dam and hourly water temperature (°C) measured at Km 227.8 by BC Hydro’s TR2 sensor, July 1 to September 30, 2012. The red arrow indicates the date one dead White Sturgeon egg was collected, black arrows when free embryos were collected and the dotted bar indicates estimated spawn timing. ........................................................................................................... 11

Figure 5: Hourly total discharge (m3/s) from Revelstoke Dam and hourly water surface elevation (meters above sea level) measured at Km 227.8 by BC Hydro’s TR2 sensor, July 1 to September 30, 2012. The red arrow indicates the date one dead White Sturgeon egg was collected, black arrows when free embryos were collected and the dotted bar indicates estimated spawn timing. .............................................. 12

Lis t of Tables

Table 1: Sample effort for CLBMON-23 Middle Columbia River White Sturgeon spawn monitoring, 2012. ....................................................................................................... 4

Table 2: Summary of egg collection mat sampling, August 1 to September 13, 2012. ........... 13Table 3: Summary of egg collection mat and drift net sampling by study year, 2007-2012. .... 13Table 4: Summary of drift net sampling, August 1 to September 13, 2012. ............................ 14Table 5: Estimated timing of spawning events based on the developmental stages of captured

White Sturgeon eggs and free embryos, August 1 to September 12, 2012. ............. 15Table 6: White Sturgeon spawning events and physical parameters observed below

Revelstoke Dam (July-August) during spawn monitoring programs, 1999 to 2012. Note that spawn monitoring was not conducted in 2002, 2004 and 2005. Table reproduced from Golder (2012). ............................................................................... 16

Lis t of Appendices

APPENDIX A Egg Collection Mat Sampling APPENDIX B Drift Net Sampling APPENDIX C Station Location Coordinates

AMEC File: VE52241-2012 Page iv

IMPORTANT NOTICE

This report was prepared exclusively for BC Hydro by AMEC Environment & Infrastructure Limited, a wholly owned subsidiary of AMEC. The quality of information, conclusions and estimates contained herein is consistent with the level of effort involved in AMEC services and based on: i) information available at the time of preparation, ii) data supplied by outside sources, and iii) the assumptions, conditions and qualifications set forth in this report. This report is intended to be used by BC Hydro only, subject to the terms and conditions of its contract with AMEC. Any other use of, or reliance on, this report by any third party is at that party’s sole risk.


AMEC File: VE52241-2012 Page v

ACKNOWLEDGEMENTS

The following people are gratefully acknowledged for assistance and information contributions during this study:

BC Hydro

James Crossman, Castlegar Margo Dennis, Burnaby Guy Martel, Burnaby Karen Bray, Revelstoke Canadian Columbia River Intertribal Fisheries Commission (CCRIFC)

Bill Green Jon Bisset Jim Clarricoates

The following employees of AMEC Environment & Infrastructure Ltd. contributed to the collection of data and preparation of this report:

Louise Porto MSc., R.P.Bio. Senior Aquatic Habitat Biologist, Co-Author Crystal Lawrence BSc., R.P.Bio. Aquatic Biologist, Co-Author Christin Davis BSc. Sturgeon Biologist, Co-Author Katherine Fraser Data Technician Matthew Yuen GIS Technician The following Subcontractors also contributed to this program: Clint Tarala Field Technician Jeremy Baxter Field Technician, Mountain Water Research Marco Marrello Field Technician, Terraquatic Resources Jim Clarricoates Field Technician, CCRIFC Bill Green Senior Review, CCRIFC


AMEC File: VE52241-2012 Page vi

EXECUTIVE SUMMARY

The Columbia River White Sturgeon Management program was initiated to address flow management issues with respect to impacts on White Sturgeon (Acipenser transmontanus) spawning events, timing, frequency, egg deposition, and habitat conditions (BC Hydro 2012). A small population of White Sturgeon has been documented in Arrow Lakes Reservoir (ALR), between Hugh L. Keenleyside (HLK) and Revelstoke (REV) dams (BC Hydro 2012). Spawning has been documented intermittently since 2003, mainly at an area approximately 5 km downstream of REV (BC Hydro 2012). Monitoring conducted in 2012 was Year 6 of the annual middle Columbia River White Sturgeon spawning monitoring study program (CLBMON-23).

White Sturgeon spawning monitoring in the middle Columbia River was conducted between August 1 and September 12, 2012 at stations between river Km 228.0 and 229.9. Methods included egg mat and larval drift D-ring net sampling, which have previously been used to capture White Sturgeon eggs and free embryos at this location. Thirteen egg mat sample sites were established and inspected weekly for the presence of White Sturgeon eggs and/or free embryos. In total, 8,773 hours of egg mat sampling effort resulted in no capture of White Sturgeon eggs or free larvae in 2012. Larval drift D-ring nets were set weekly at two to five locations for an average of 3.8 hours per set. In total, 107 hours of larval drift net sampling effort resulted in the capture of one dead White Sturgeon egg (CPUE = 0.01/hour) on August 1 and seven free embryos (CPUE = 0.07/hour or 0.01/100 m3 of water sampled), two of which were captured on August 10 and five of which were captured on August 17, 2012. The capture timing of the one dead egg and the developmental stages of the free embryos suggested that approximately one spawning event occurred between July 25 and August 4, 2012 (Table 5).

Middle Columbia River discharge reached a higher peak (2,573 m3/s on July 21, 2012) than has been observed over the past five years of CLBMON-23. Discharge continued to reach near this peak throughout the 2012 monitoring period, which resulted in higher flows throughout the spawning period compared with previous years. The surface elevation of ALR resulted in a backwatering effect in the sample area until late August, which was later than this effect has been observed in this area in previous years.

The current state of knowledge for White Sturgeon spawning below Revelstoke Dam with respect to BC Hydro’s management questions for CLBMON-23 is provided in the table below.

Management Ques tion Sta tus Where are the primary White Sturgeon incubation sites below Revelstoke Dam?

Based on White Sturgeon spawning studies conducted below Revelstoke Dam since 1999, the primary White Sturgeon spawning and egg incubation area is located adjacent to the Revelstoke golf course, beginning across from the mouth of the Jordan River and extending approximately 0.8 km upstream (Golder 2009 and Golder 2012a). In 2012, one egg and seven free embryos were collected between Km 228.7 and Km 229.9 within the primary spawning area observed during past studies.


AMEC File: VE52241-2012 Page vii

How do dam and reservoir operations affect egg and free embryos survival in this area? Specifically, do significant numbers of eggs become dewatered as a result of operations?

In 2012, water levels did not fluctuate enough during the White Sturgeon spawning period to expose the gravel bar where White Sturgeon eggs have been observed stranded (Golder 2010). This was likely due to the high discharge from REV and backwatering influence from ALR throughout the sturgeon spawning period.

What is the most effective method for monitoring spawning of White Sturgeon?

In previous years, eggs and/or free embryos have been captured on egg collection mats and in larval drift D-ring samplers. In 2012, eggs and free embryos were only collected in larval drift nets. This may have been a function of the high discharge and water levels that precluded effective sampling with egg mats in the thalweg or a result of higher drift net sampling effort in 2012 than in previous years.

Can modifications be made to operation of Revelstoke Dam and Arrow Lakes Reservoir to protect or enhance White Sturgeon incubation habitat?

Changes to REV operations in late 2010 resulted in an increase in minimum flows and discharge capacity at REV. Additional information on the effects of fluctuating discharge, water temperatures and elevations on White Sturgeon spawning activity and embryo development is required for the middle Columbia River to address this management question. The influence of REV operations and ALR elevation on the physical conditions observed at the spawning area is also being identified during concurrent BC Hydro Water License Requirements (WLR) programs.


AMEC File: VE52241-2012 Page 1

1.0 INTRODUCTION White Sturgeon (Acipenser transmontanus) have experienced reduced population abundance in the Columbia River due to recruitment failure, lowered food resources, and degradation or lack of access to suitable habitats (Porto 2008) and were listed as endangered under federal Species at Risk Act (SARA) legislation in 2006. The Columbia River population is considered at significant risk of extinction in the wild given strong evidence that, for several decades, natural recruitment has been too low to sustain this population (UCWSRI 2002).

A small component of the Columbia River population resides in the area between Revelstoke Dam (REV) and Hugh L. Keenleyside Dam (HLK), which includes the Arrow Lakes Reservoir (ALR; Figure 1). This population component, referenced as the middle or middle Columbia River population, is comprised of approximately 52 adult White Sturgeon (population estimate ranges between 37 - 92 individuals) that are older than the 1969 age class (Golder 2006; Porto 2008). Natural spawning has been documented downstream of the REV tailrace, near the Revelstoke Golf Course (R.L. & L. Environmental Services Ltd. 2000), but spawning has been intermittent and naturally produced juvenile White Sturgeon have never been captured (UCWSRI 2002). Spawning investigations occurred in 2000, 2001, 2003, 2006, 2008, 2009, 2010, and 2011 with spawning events documented in 2003, 2006, 2008, 2009 and 2011 (Golder 2012a). Spawn timing has been confirmed to occur from late July through August and this area represents the only known spawning area for White Sturgeon in the ALR (BC Hydro 2012).

Revelstoke Dam was built in 1984 and its operations are a function of discharges from the Mica Dam and local inflows to Revelstoke reservoir. In turn, Mica Dam discharges are regulated by the Columbia River Treaty (CRT) and the Non-Treaty Storage Agreement. REV is a hydropeaking facility and since early 2011 discharges within a 24 hour period have varied between the operational minimum of 145 m³/s to approximately 2100 m³/s (BC Hydro 2012, Golder 2012a). Prior to the installation of a fifth turbine unit in December 2010, referred to as ‘REV5’, flows could be varied from zero to approximately 1700 m3/s (Golder 2012a). The effect of hydropeaking operations at REV is a constant variation in flow rates at the White Sturgeon spawning area downstream of the REV tailrace. Further adding to the complex flow regime is a backwatering effect observed as far upstream as REV when ALR water levels exceed 437 meters above sea level, which generally occurs during the White Sturgeon spawning period.

BC Hydro has funded a number of White Sturgeon investigations in ALR since 1995, which has included spawn monitoring downstream of REV. Annual spawn monitoring below REV is required under the terms of the Columbia River Project Water Licence (WLR) Order to document spawning events, timing, frequency, egg deposition, and habitat conditions (BC Hydro 2012). Spawn monitoring studies under BC Hydro’s WLR process were carried out from 2007 to 2011 below REV (CLBMON-23A) with concurrent studies that assessed the feasibility of sonar techniques for detecting adult White Sturgeon within the spawning area (CLBMON-23B; as cited in Golder 2012a; Crossman et al. 2011). An additional five years of spawning investigations were initiated to document spawning events, timing, frequency, egg deposition, and habitat conditions to inform future management decisions.



1.1 Objectives The primary objectives of this monitoring program are to (BC Hydro 2012):

1. Assess sturgeon incubation sites and conditions downstream of Revelstoke Dam;

2. Relate egg stranding risk to discharge from the dam and water elevation of Arrow Reservoir;

3. Assess the feasibility of underwater videography or other remote sensing techniques for monitoring presence of White Sturgeon spawners (already covered under CLBMON-23B);

4. Select and implement the most effective method (egg mats or videography or other remote sensing) for ongoing monitoring of spawning of White Sturgeon (already covered during previous studies conducted under CLBMON-23A and 23B); and

5. Provide input to recommendations for the water allocation schedule for White Sturgeon spawning and incubation.

The fundamental Management Questions to be addressed through this study are (BC Hydro 2012):

1. Where are the primary White Sturgeon incubation sites below Revelstoke Dam?

2. How do dam and reservoir operations affect egg and larvae/free embryos survival in this area? Specifically, do significant numbers of eggs become dewatered as a result of operations?

3. Can underwater videography or other remote sensing methods be used to effectively monitor staging and spawning of White Sturgeon?1

4. What is the most effective method for monitoring spawning of White Sturgeon?

5. Can modifications be made to operation of Revelstoke Dam and Arrow Lakes Reservoir to protect or enhance White Sturgeon incubation habitat?

1.2 Purpose The following report fulfills AMEC’s commitment to provide BC Hydro with a data report for studies conducted in 2012 and adds to the dataset collected in previous years.

1 This management question was addressed under a different program (CLBMON-23B Mid-Columbia River White Sturgeon underwater videography feasibility study; Johnson et al. 2009) and will not be further addressed by the present program.

ReferenceBase data: hydrology - BC Watershed Atlas (1:50,000 scale)

June, 2012

VE2012P-109

UTM Zone 11

DATE:

JOB No:

PROJECTION:

ANALYST: FigureMYPDF FILE:

01-50-001_overview_map.pdf

GIS FILE:01-50-001.mxd

NAD83DATUM:

Overview map of the middle Columbia River depicting hydroelectric facilities

PROJECT: CLBMON-23 Mid-Columbia River White Sturgeon Spawn Monitoring

QA/QC:

LP

CLIENT:

BC Hydro

COLUMBIA RIVER

Seymour River

COLUMBIA RIVER

Adams

Lake

SHUSWAPLAKE

Duncan River Kootenay RiverTroutUPPER ARROW LAKE

LakeMabelLake

WindermereLake

DuncanLake

KOOTENAY River

ColumbiaLake

Kalamalka

Lake

SlocanLake

LOWER ARROW

LAKE

KOOTENAY LAKE

Revelstoke Dam

Hugh L. Keenelyside Dam

Nelson

Vernon

Kimberley

Cranbrook

Castlegar

Revelstoke

Salmon Arm

Spallumcheen

LegendDamCity / TownRoadRiverWaterbodyBC/Alberta Border

1:1,000,000Scale:10 0 10 205

Kilometres

Y:\G

IS\P

ropo

sals

\VE

2012

P-1

09_W

hite

_Stu

rgeo

n\M

appi

ng\0

1-50

-001

.mxd

ben.brown

Typewritten Text

1



2.0 METHODS 2.1 Study Area The study area included the spawning area from Revelstoke Dam (Km 235) to just upstream of Big Eddy (Km 228; Figure 2), consistent with monitoring conducted during the first five years of this program (Golder 2012a). Sites were concentrated in the area where over 97% of White Sturgeon eggs have been captured since 2000, from Km 228 to Km 229 (Golder 2012a; Figure 2).

2.2 Environmental Parameters In order to help answer Management Questions 2 and 4 pertaining to operations and dewatering, environmental parameters were monitored during the program. Hourly discharge (m3/s) from REV, separated by turbine and spillway flow, and water surface elevation (meters above sea level) of ALR at Nakusp were obtained from BC Hydro Power Records. Water temperature (°C) and water surface elevation collected at 10 minute intervals just downstream of the spawning area (Km 227.8) by BC Hydro’s TR2 sensor were also obtained from BC Hydro. Two thermograph stations, both with Onset TidbiT v2 loggers accurate to 0.2°C, were set up to provide a redundant method for collecting water temperatures within the spawning area (Figure 2). Their locations were in both the upper portion of the 2012 study area (Km 229.5) and at the lower end of the study area, downstream of Big Eddy (Km 228.1). Both water temperature monitoring stations were located on the east side of the river (left downstream bank).

2.3 Sample Timing The sampling period occurred from August 1 to September 13, 2012 during the known White Sturgeon egg incubation period below Revelstoke Dam. The onset of sampling was delayed by one week due to high water levels and associated REV discharge. A summary of field sample sessions is provided in Table 1.

Table 1: Sample effort for CLBMON-23 Middle Columbia River White Sturgeon spawn monitoring, 2012.

aDrift nets deployed only on second day.

Session DateNo. Egg

Mats Deployed

No. Drift Nets

Deployed1 Aug. 1 2 22 Aug. 9 & 10 8 53 Aug. 16 & 17 11 4a

4 Aug. 22 & 23 13 4a

5 Aug. 29 & 30 14 5a

6 Sep. 5 & 6 13 4a

7 Sep. 12 0 4a



2.4 Spawn Monitoring

2.4.1 Egg Collection Mats In order to continue baseline spawn monitoring below REV, standard egg mats (cf. below) were used to collect White Sturgeon eggs/free embryos that drifted during spawning events. This method has been successfully used in the middle Columbia River to monitor White Sturgeon spawning (e.g., Golder 2012a) and has been used throughout the Columbia basin in both Canada and the US to monitor other White Sturgeon populations (e.g., McCabe and Beckman 1990). Previous studies have determined that the most effective method for monitoring White Sturgeon spawning in the study area (Management Question 4) is a combination of egg mat and drift net sampling (Golder 2012a).

Egg mats were retrieved/deployed from a boat as per BC Hydro’s Specific Work Instructions (see Health & Safety Plan). Thirteen egg mat stations were deployed (10 set to shore and 3 middle channel sets) and concentrated in the spawning area between Km 229.9 and 228.0. A combination of nearshore and mid-channel egg mat sets have been used below REV to adequately cover potential spawning areas across the river channel (e.g. Golder 2012a). High water during the 2012 monitoring period resulted in fewer mid-channel and more nearshore sets than during previous years at this location.

Each egg mat was comprised of a steel frame that enclosed latex covered animal hair filter material. The filter material was present on both sides of the frame, so when deployed, one side of the filter material was always sitting upward where drifting eggs and free embryos could lodge and attach. Egg mat dimensions were approximately 0.77 m by 0.92 m.

The egg mat system consisted of two 30 kg claw anchors attached to one another with an approximately 6 m galvanized steel chain and a float line which attached to the front anchor; a 10 m rope attached the rear anchor to the egg mat with a second float line (15 to 45 m) coming off the rear of the egg mat for retrieval. The lengths of rope used depended on depth and degree of flow fluctuations that were encountered.

Egg mats had a rope bridle system attached to each end, so that one end was attached to the rope/chain/anchor and the other bridle had a separate float line for retrieval. The retrieval float line was pulled up by the field crew, wrapped around the winch of the boat (which was permanently affixed to the bow) and used to pull the egg mat up. The egg mat was detached from the rope system and a spare egg mat was attached to the rope system and deployed. The boat operator drove to the shore and the field crew inspected the egg mat. Near shore egg mat sample locations were tied to shore instead of having a second float line. Having two float lines on mid-channel sets allowed the field crew to pull up the egg mat directly, but also the float line attached to the anchor provided a secondary means to pull up the egg mat set, should there have been a problem with the egg mat float line.

Data collected at each egg mat included: station name (e.g., J30 = retrieval buoy labelled J30); UTM; channel location (L= left bank when facing downstream and M = mid-channel); set and pull date and time; water temperature; set depth; number of eggs; number of free embryos; number of eggs/free embryos preserved; other species/observations; and, any relevant comments. If egg mats drifted significantly, they were moved back to their original location and noted in the comments; no new site designation was required. Data was



recorded on standard data sheets set up for this program (see attached). A photograph of each data sheet was taken during each field session to provide a back up. In the office, all data sheets were additionally scanned and then entered into MS Excel. GIS was used to convert each site UTM collected in the field to a river kilometre with channel location designation (e.g. 229.0L = river Km 229.0; L = left downstream bank). QA/QC was completed by the Data Manager (Crystal Lawrence) who checked entered data for errors by comparing to field data sheets. Detailed site maps for each egg mat location are provided (Figure 2). Catch-per-unit effort (CPUE) was calculated for each egg mat (number of White Sturgeon eggs/hour of effort) for comparison between sampling years.



Figure 2: Study area and sample site locations for Middle Columbia River White Sturgeon spawn monitoring below Revelstoke Dam, 2012.



2.4.2 D-Ring Larval Drift Nets In addition to the use of egg mats, collection of White Sturgeon eggs/free embryos was monitored using D-ring larval drift nets (referred hereafter as drift nets). This method has been successfully used to collect White Sturgeon eggs/free embryos in the middle and lower Columbia rivers as well as throughout the Columbia River in the US. Drift nets consist of a D-shaped metal frame (0.8 m wide by 0.6 m high) with an attached net (3.6 m long, 0.16 cm knotless mesh, 11.4 cm diameter collection bottle). Researchers maintained an upright sampling position of the D-ring by using weights at the front corners (approximately 4.5 kg lead weight attached to each corner) in order to more effectively sample drifting debris/aquatic life (e.g., Howell and McLellan 2006 as cited in Golder 2012a; personal observations). In addition, a flow meter (e.g., General Oceanics) was fixed to the D-ring frame at the top of the opening to measure the volume of water sampled; this method has been used previously for drift net sampling in the middle Columbia River (e.g., Golder 2012a).

Drift nets were deployed at the start of the second field day and were fished for ~3 hours. Drift nets have previously been set on two consecutive days per week in the middle Columbia River (e.g., Golder 2012a). However, additional effort was required to deploy additional egg mat anchor locations on the first field day each week in 2012 as high water levels at the program outset had prevented deployment. Therefore, field sessions included checking and redeployment of half the egg mats and deployment of additional anchor sites on Day 1 while Day 2 included drift net sampling, checking and redeploying remaining egg mats and relocation or removal of anchors set the previous day if significant downstream displacement was observed.

Drift net sites were selected to cover the upper, middle and lower portion of the spawn monitoring area during each field survey. Drift net anchor sites were established during the first field session when egg mats were set and two drift nets were deployed as a trial for that day. Two 30 kg claw anchors were used for drift net sites. Anchors had approximately 20 ft of galvanized steel chain between them. The first anchor had a float line attached and the second anchor had a section of chain then rope to attach the drift net. The bottom end of the drift net frame was clipped onto this chain/rope line. A second float line for retrieval was attached to the top of the drift net frame. Retrieval of the drift net was similar to the egg mat in that the float line was retrieved and the winch used to pull the drift net into the boat. The drift net was detached and the float line reattached. Two drift net anchor sites (229.0L and 229.4L) were consistently used for the duration of the project. Additional drift nets were set at other sites (228.0L, 228.7L, 228.75L, 229.2L 229.7L and 229.9L) over the duration of the sampling period. Drift nets were set on the same anchor systems and/or rope used for egg mat sampling (Section 2.4.1).

Upon retrieval of the drift nets, the contents of the bottle and drift net were emptied into a white bucket. The contents of the bucket were further diluted with river water into small white wash basins and field crew members sorted through the debris to find any White Sturgeon eggs/free embryos using tweezers. Trial overnight sets were conducted at two drift net anchor sites on the night of August 9, but were discontinued for the duration of the sampling period because debris accumulation filled the collection cups above capacity or blew out the



mesh lining. Data recorded for drift net sampling included: station name (similar to egg mats); river km and channel location; set and pull date and time; water temperature; set depth; start/end readings of the flow meter for calculation of water volume sampled; number of eggs/ free embryos; number preserved; other species observed; and, relevant comments (e.g., drifting of station, quantity of debris, whether eggs/free embryos were alive/dead). Data recording, entry and QA/QC followed that outlined for egg mats above. Detailed site maps for drift net locations are provided (Figure 2). Catch-per-unit effort (CPUE) was calculated for each drift net (number of White Sturgeon/hour and number/100 m3 water volume) for comparison with other sampling years.

2.5 Egg Incubation White Sturgeon eggs were immediately staged on the boat upon capture. If this had not been possible, then eggs were to be preserved in Prefer and staged by dissection microscope in the office. Eggs staged in the field were loaded into incubation capsules and fixed in the river in a location close to the point of capture and incubated until free embryos were observed. Free embryos were then collected and preserved in 90% ethanol to be used in future parental lineage investigations.

2.6 Egg Stranding In order to address whether White Sturgeon eggs become dewatered as a result of operations (Management Question 2), stranding surveys were to be conducted when White Sturgeon spawning event(s) occurred. The area identified where White Sturgeon eggs have been previously observed to dewater includes a cobble/gravel bar across from the mouth of the Jordan River (~Km 228; Figure 2). However, flow reduction sampling did not occur due to high water levels experienced throughout the 2012 White Sturgeon spawning and incubation period.

2.7 Preservation, Staging & Spawn Timing Estimation In order to address Management Question 2 related to survival and spawn timing, captured White Sturgeon eggs/free embryos were staged to estimate spawn timing and number of spawning events that occurred during the study program. As discussed above, captured eggs were staged immediately in 2012. Free embryos were preserved in 90% ethanol for further inspection and DNA analyses. Standard egg staging procedures were used as described in Dettlaff et al. (1993) and Wang et al. (1985). Egg and free embryo stages were used with mean water temperatures observed during sampling to estimate the number and timing of spawning events (Wang et al. 1985). The total number of eggs/free embryos, status (alive/dead/damaged), spawn timing and number of estimated spawning events were summarized. In the case of any free embryo stages falling between those noted by Wang et al. 1985, a range was calculated to cover the possible spawn timing.



3.0 RESULT S 3.1 Environmental Parameters – Discharge, Water Temperature & Elevation Discharge from Revelstoke Dam exhibited daily fluctuation between April 1 and September 30, 2012 due to the hydropeaking operations at the facility (Figure 3). Arrow Lake Reservoir elevation steadily increased between April and July, reaching a peak elevation of 440.53 m above sea level (masl) in late July and gradually decreased from mid-August through the remaining study period (Figure 3).

Figure 3: Hourly total discharge (m3/s) from Revelstoke Dam (REV) and hourly water level elevation (meters above sea level) of Arrow Lakes Reservoir (ALR) as measured in Nakusp, BC, April 1 to September 30, 2012.

Peak discharge occurred in late July (2,573 m3/s on July 21 at 00:00); this occurred during a spill operation, which lasted six days, from July 18 to July 24 (Figure 4). The maximum daily discharge continued to reach levels up to 2,200 m3/s through September 8 in 2012 (Figure 4). Minimum discharge (145 m3/s) was observed during all periods except during the typical spawning window between mid-July and mid-August. During this period, discharges remained near maximum, between approximately 1,600 and 2,570 m3/s, from July 16 to 30 (Figures 3 and 4). The intensity and duration of the peak discharge period during sampling

426

428

430

432

434

436

438

440

442

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

2,200

2,400

2,600

2,800

Elevation (m

asl)

Discharge

(m3/s)

Date

REV Discharge

ALR Elevation



was higher than that observed during the previous five years of the program. Discharge generally peaked at approximately 1,700 m3/s between July and August from 2007 to 2010 (Golder 2008, 2009, 2010, 2011). Following the addition of a fifth operational unit at REV in late 2010, peak levels reached approximately 2,100 m3/s during the 2011 spawning period (Golder 2012a). However, between 2007 and 2011, discharges ≥1,700 m3/s were not maintained for periods longer than 2 to 3 days during the summer months.

Water temperatures at the spawning area are the result of a combination of thermal conditions in the REV forebay, REV discharge volume and backwater effect from ALR (Golder 2011). Water temperature fluctuated between 7.8°C and 13.5°C during the July through September period (Figure 4). The greatest hourly fluctuations in water temperature observed during the study period occurred on July 10 when the temperature increased from 9.0 °C at 01:00 to 9.8 °C at 02:00 (0.8 °C/hr) and decreased from 10.1 °C at 09:00 to 9.4 °C at 10:00 (0.7 °C/hr; Figure 4). One other water temperature increase of 0.7 °C/hr was recorded on July 15 when the temperature increased from 9.4 °C at 06:00 to 10.1 °C at 07:00.

Figure 4: Hourly total discharge (m3/s) from Revelstoke Dam and hourly water temperature (°C) measured at Km 227.8 by BC Hydro’s TR2 sensor, July 1 to September 30, 2012. The red arrow indicates the date one dead White Sturgeon egg was collected, black arrows when free embryos were collected and the dotted bar indicates estimated spawn timing.

8

9

10

11

12

13

14

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

2,200

2,400

2,600

2,800

Temperature (°C)

Discharge

(m3/s)

Date

Discharge

Temperature



Water level elevation over the spawning area reached its seasonal maximum during late July with the highest elevation of 441.0 masl (as measured at BC Hydro’s TR2 sensor located at Km 227.8) on July 23 at 12:00 (Figure 5). Elevation remained stable during the period of maximum discharge from REV. Daily fluctuations in elevation were moderate (<0.8 m/day) from this period until August 20 when fluctuations increased (>1.0 m/day). Fluctuations were highest at the end of the sample period and a fluctuation of 2.7 m/day on September 6 and 7 were the greatest observed (Figure 5). The magnitude of water level fluctuation at the spawning area is affected by the backwatering effect of ALR (reduced backwatering results in increased water level fluctuations), which declines when surface elevation at Nakusp drops below 437 masl (Golder 2011). This occurred on August 29 in 2012 and reservoir elevation was maintained below this level for the remainder of the study period (Figures 3 and 5).

Figure 5: Hourly total discharge (m3/s) from Revelstoke Dam and hourly water surface elevation (meters above sea level) measured at Km 227.8 by BC Hydro’s TR2 sensor, July 1 to September 30, 2012. The red arrow indicates the date one dead White Sturgeon egg was collected, black arrows when free embryos were collected and the dotted bar indicates estimated spawn timing.

435.5

436.0

436.5

437.0

437.5

438.0

438.5

439.0

439.5

440.0

440.5

441.0

441.5

442.0

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

2,200

2,400

2,600

2,800

Elevation (m

asl)

Discharge

(m3/s)

Date

Discharge

Elevation



3.2 White Sturgeon Egg & Free Embryo Collection

3.2.1 Egg Collection Mats A total of 8,773 mat-hours of effort (mean sample duration per egg mat = 143.8 hours; SD = 44.6) were spent during the 2012 sampling period (Table 2; Appendix A). However, no White Sturgeon eggs/free embryos were collected by egg mats. Effort expended in 2012 was lower than in previous years due to high water levels experienced during the first half of the program (Table 3). Therefore, egg mats could only be set along the slower river margins and mid-channel (thalweg) sets were not possible.

Table 2: Summary of egg collection mat sampling, August 1 to September 13, 2012.

a Sample period was delayed by one week due to high water levels. b CPUE = no. White Sturgeon eggs/24 mat-hours.

Table 3: Summary of egg collection mat and drift net sampling by study year, 2007-2012.

3.2.2 Drift Nets Drift nets (n=28) were set for a total of 107 hours (mean sample duration per net = 3.8 hours; SD = 3.4) during the 2012 sampling period (Table 4; Appendix B). Drift net sampling effort was similar among sample sessions with the exception of two sessions: i) August 1 – initial drift net trial; and, ii) August 9 and 10 – overnight drift net set trial. It was determined that drift nets could only be set during the day since the nets set during the overnight trial period (15-16 hours) were completely full of debris and one net was blown out.

In total, one White Sturgeon egg and seven free embryos were captured by drift nets (Table 4). One egg was collected on August 1, one hatching egg (considered a free embryo as

Session Datea No. Mats Deployed

No. Mats Retrieved

Effort (Mat-

Hours)

No. Eggs /Free

Embryos

Catch-Per-Unit-Effort (CPUE)b

1 Aug. 1 2 0 0.00 N/A N/A2 Aug. 9 & 10 8 2 392.92 0.00 0.003 Aug. 16 & 17 11 8 1276.03 0.00 0.004 Aug. 22 & 23 13 11 1245.62 0.00 0.005 Aug. 29 & 30 14 13 1983.23 0.00 0.006 Sep. 5 & 6 13 14 1971.41 0.00 0.007 Sep. 12 0 13 1903.62 0.00 0.00

61 61 8772.83 0.00 0.00Totalsremoved all egg mats

Notes

Initial session

No. Deployed

Total Effort (hrs)

CPUE No. Deployed

Total Effort (hrs)

CPUE

2012 61 8,773 0 28 106.8 0.07 Current Study2011 128 22,169 0.03 23 61.2 0.30 Golder 20122010 96 20,514 0 15 67.4 0 Golder 20112009 115 18,860 0.05 22 65.3 0.70 Golder 20102008 164 27,009 0.004 6 12.6 0.30 Golder 20092007 136 25,818 0 8 24.7 0 Golder 2008

ReferenceStudy YearEgg Mats Drift Nets



hatching was observed) and one free embryo were collected on August 10 and five additional free embryos were captured on August 17 (Table 4). White Sturgeon eggs/free embryos were collected in the main spawning area at sites along the left downstream bank. The egg collected on August 1 was located in the middle section of the 2012 sample area (229.4L). The seven free embryos were captured at four sites distributed throughout the study area (228.7L, 229.4L, 229.7L and 229.9L; Figure 2). Overall, catch-per-unit effort (CPUE) for White Sturgeon eggs collected by drift nets was 0.01/hour (0.24/24 hours) and the total volume of water sampled was not collected (Table 4). CPUE for free embryos was 0.07/hour (1.7/24 hours) or 0.01/100 m3 of water sampled (Table 4).

Table 4: Summary of drift net sampling, August 1 to September 13, 2012.

a Velocity meters not used during these sets. b Drift nets set overnight and velocity meter readings could not be determined as meters zeroed themselves an unknown number of times. c Total free embryo CPUE (No./ 100 m3) does not include water volume sampled on August 1 and 9 as values were not available on these dates.

3.3 Staging & Estimated Spawn Timing

In total, one White Sturgeon egg and seven free embryos were captured during the study (Section 3.2) and all were preserved in ethanol with the exception of one free embryo, which was inadvertently released into the river. Preserved free embryos were all suitable for developmental staging; staging was not possible for the one egg that was dead upon capture.

Free embryos were captured on August 10 (n=2) and August 17 (n=5) (Table 5). Predominant features (or lack thereof) for newly hatched embryos included the lack of a mouth opening, pectoral fins or gill clefts. Samples collected on August 10 were observed to be newly hatched and were classified in the first of the free embryo stages (stage 36; Table 5). Based on Wang et al. (1985), the development rate for White Sturgeon to reach stage 36 is approximately 311 hours at 11°C; this resulted in an estimated spawn time of July 28, 2011.

The free embryos collected on August 17 were more developed than those collected on August 10. These free embryos ranged in their development stages (between stage 37 and 39) with some displaying more developed barbels, gill clefts, mouths and pectoral fins than others (Table 5). Two of the five free embryos observed on August 17 also had more development in the brain and heart areas. Wang et al. (1985) described the development

Duration (hr)

Estimated Volume

(m3)No./hr No./ 100 m3 No./hr No./ 100 m3

1 Aug. 1 2 4.50 -a 1 0.22 -a 0 0.00 -a

2 Aug. 9 2 31.44 -b 0 0.00 -b 0 0.00 -b overnight set trial2 Aug. 10 3 12.53 9546 0 0.00 0 2 0.16 0.023 Aug. 17 4 10.96 10854 0 0.00 0 5 0.46 0.054 Aug. 23 4 11.71 11485 0 0.00 0 0 0.00 0.005 Aug. 30 5 12.09 17565 0 0.00 0 0 0.00 0.006 Sep. 6 4 12.70 19000 0 0.00 0 0 0.00 0.007 Sep. 12 4 10.90 10441 0 0.00 0 0 0.00 0.00

28 106.83 78891 1 0.01 -a 7 0.07 0.01 c

Notes

White Sturgeon Eggs White Sturgeon Free Embryos

No. No.

Catch-Per-Unit-Effort (CPUE)

Catch-Per-Unit-Effort (CPUE)

Session DateNo. Drift

Nets Deployed

Sample Effort

Totals



rates for free embryos at stages 36 and 40 at 11°C to be 311 and 544 hours, respectively. As the five free embryos collected on August 17 fell between those stages, spawn timing was estimated to occur between July 25 and August 4 (Table 5). This range also includes the spawn date for the embryos collected on August 10 and it was therefore estimated that all free embryos collected in 2012 were from the same spawning event. Therefore, the developmental stages of the six free embryos suggested that approximately one spawning event occurred between July 25 and August 4, 2012 (Table 5). These estimations of spawn timing are an approximation as they are solely based on the stages of free embryos, as staging of the one egg captured in 2012 was not possible. In general, back calculation of White Sturgeon spawning dates are more robust when earlier embryonic stages are used (Wang et al. 1985). Variability in water temperature during the incubation period may have affected the development of free embryos captured in 2012 (Parsley at al. 2012). Though the average water temperature at the spawning location was 11°C during the incubation period, a number of temperature fluctuations occurred between the estimated spawn date and that of capture (between 9.8 and 13.5 °C; Figure 4).

Table 5: Estimated timing of spawning events based on the developmental stages of captured White Sturgeon eggs and free embryos, August 1 to September 12, 2012.

a See Figure 2 for locations. b Based on Wang et al. 1985 and Dettlaff et al. 1993.

3.4 White Sturgeon Spawning and Physical Parameters A summary of White Sturgeon spawning events and physical parameters observed below Revelstoke Dam during the spawning period (July-August) in years where spawn monitoring was conducted is provided in Table 6. The number of White Sturgeon spawning events recorded between 1999 and 2012 has varied from zero to three (Table 6). Maximum discharges were higher in 2011 and 2012 than other years that spawning monitoring was conducted; minimum discharge was also higher during those years (i.e. no flow events did not occur in 2011 and 2012; Table 6).

Collection Date

Sample Locationa

Egg/Free Embryo Stage Water

Temperature (°C)Estimated Spawn

Dateb Description

1-Aug-12 229.4L Egg 29 10.6 N/A dead10-Aug-12 228.7L Free Embryo 36 11.8 28-Jul-12 hatching observed - free embryo released10-Aug-12 228.7L Free Embryo 36 11.8 28-Jul-12 no development of head, gills or fins17-Aug-12 229.7L Free Embryo 38 11.9 25-Jul to 4-Aug-12 barbels and pectoral fins forming; mouth formed

17-Aug-12 229.9L Free Embryo 39 11.9 25-Jul to 4-Aug-12development of pectoral fins, brain and heart area; evident line on the yolk sac from the pectoral fin to the heart; barbels forming and gills becoming more developed

17-Aug-12 229.9L Free Embryo 39 11.9 25-Jul to 4-Aug-12development of pectoral fins, brain and heart area; evident line on the yolk sac from the pectoral fin to the heart; barbels forming and gills becoming more developed

17-Aug-12 229.4L Free Embryo 38 12 25-Jul to 4-Aug-12 mouth open and barbels starting to form; yolk sac was popped so hard to get a good look at sample

17-Aug-12 229.4L Free Embryo 37 12 25-Jul to 4-Aug-12 largest of all the free embryos, but no development of pec fins or gills; mouth is formed



Table 6: White Sturgeon spawning events and physical parameters observed below Revelstoke Dam (July-August) during spawn monitoring programs, 1999 to 2012. Note that spawn monitoring was not conducted in 2002, 2004 and 2005. Table reproduced from Golder (2012).

a Temperature data were only available from August 4-31. b Data not available.

1999 2000 2001 2003 2006 2007 2008 2009 2010 2011 20123 0 0 2 1 0 2 3 0 3 182 0 0 50 1 0 8 65 0 37 10 0 0 1 0 0 0 18 0 11 7

Mean 1230 1139 682 901 939 1185 712 744 540 957 1506Min. 0 0 0 0 0 0 0 0 0 145 150Max 1838 1635 1612 1667 1630 1773 1752 1715 1757 2140 2573Mean 10.3a 9.8 9.5 10 9.7 9.2 10.9 11 10.6 10.8Min. 9.2a 6.4 6.9 8 4.5 6.7 7.6 7.5 8 7.8Max 11.6a 13.1 13.6 13.1 12.9 11.8 16.2 14.2 12.5 13.5Mean 438 438.9 429.4 438 438.1 437.5 439.2 436.5 437.7 439 439.5Min. 437.2 437.6 427.3 436.2 435.2 435.3 438.7 435.8 436.1 438 436.6Max 440 444 430.4 439 439.8 438.6 439.9 437.5 439.3 439.5 440.5

25 8 36 36 12 8 49 42 39 0 0

Parameter

Discharge (m3/s)

Water Temperature (°C)

ALR Water Surface Elevation at Nakusp (m above sea level)

-b

No. Spawning EventsNo. Eggs CapturedNo. Free Embryos Captured

No. Zero Flow Events



4.0 DISCUSSION The following discussion is structured along the management questions.

4.1 Management Question 1: Where are the primary White Sturgeon incubation sites below Revelstoke Dam?

Based on White Sturgeon spawning studies conducted below Revelstoke Dam since 1999, the primary White Sturgeon spawning and egg incubation area is located adjacent to the Revelstoke golf course, beginning across from the mouth of the Jordan River and extending approximately 0.8 km upstream (Golder 2009 and Golder 2012a). In 2012, eggs and free embryos were collected between Km 228.7 and Km 229.9, which was mainly within the primary spawning area observed during past studies as well as slightly upstream. Sampling in 2012 was only conducted within the primary spawning area identified during past studies. Previous sampling has occurred in areas upstream and downstream of the 2012 sample area (Golder 2012a). In 2008, one egg was captured approximately 1 km upstream of the primary spawning area and in 2011, the majority of eggs were captured from 0.2 to 0.7 km upstream of the primary spawning area (Golder 2012a).

The interaction between REV discharge and ALR elevation may influence spawning locations in the middle Columbia River. Previous egg capture and DIDSON monitoring suggest White Sturgeon use of upstream areas is low (Golder 2012a, Crossman et al. 2011). However, on years when eggs were collected in upstream areas, ALR water surface elevations were the highest of all years sampled (Table 6) which resulted in a backwatering effect at the White Sturgeon spawning area near Revelstoke Golf Course. It has been suggested that backwatering in the spawning area may result in reduced velocities which may redistribute spawners to upstream areas where velocities are greater (Golder 2012a). Columbia River White Sturgeon spawn in turbulent, high velocity (>0.8 m/s mean water column velocity) areas (Parsley et al. 1993). As the backwatering influence was present at the spawning area for the majority of the study period in 2012, spawners may have used slightly upstream areas as free embryos were captured as far upstream as Km 229.9. However, it should be noted that discharge during this period was notably higher than during previous years, which may have negated the backwater influence and maintained velocities throughout the spawning area. Data collected during concurrent WLR programs in the middle Columbia will help address how velocities change with respect to ALR levels and REV discharge.

4.2 Management Question 2: How do dam and reservoir operations affect egg and larval survival in this area? Specifically, do significant numbers of eggs become dewatered as a result of operations?

In 2012, water elevation did not fluctuate to low enough levels during the White Sturgeon spawning period to expose the gravel bar where White Sturgeon eggs have previously been observed stranded (Golder 2010). This was due to the high discharge from REV and the backwatering influence from ALR throughout the 2012 spawning monitoring period.

The operational regime of REV has changed over the course of spawning monitoring surveys in the middle Columbia River. Prior to the installation of a fifth unit at REV (REV5) in December 2010, REV flows could be varied between zero and 1,700 m3/s. Prior to the 2011



spawning period, zero flow events occurred during the spawning period (late July to early September) in all years monitoring was conducted (Table 6). Upon installation and start-up of REV5, the minimum flow requirement at REV increased to 145 m³/s; the estimated maximum also increased to 2,100 m³/s due to new operational capacity. The increase in minimum flows and overall capacity has increase the estimated total wetted riverbed area in the middle Columbia River by approximately 37% when ALR is below 425 m (Golder 2012b).

Flow modelling was used to determine if the egg incubation areas would be exposed during no flow periods following spawning events. During the initial 5-years of this program, egg stranding surveys were conducted twice to investigate exposure of incubation areas, once in 2009 when minimum REV flow was zero and once in 2011 when minimum REV flow was 145 m3/s (Golder 2012a). In 2009, seven White Sturgeon eggs were recorded in the 29 m2 of exposed gravel bar surveyed, which resulted in a density estimate of 0.24 stranded eggs/m2 and a potential estimated 7,600 stranded eggs over the entire 31,600 m2 area assuming egg density was the same over the entire gravel bar (Golder 2010). In 2011, no eggs were observed in the 30 m2 of exposed gravel bar surveyed when approximately 8000 m2 of the bar was dewatered (Golder 2012a).

Changes in the operational regime and capacity of REV since December 2010 and observations during low flow periods suggest significant numbers of eggs do not become dewatered as a result of operations. Additional observations in years without sustained high reservoir elevations through the White Sturgeon spawning and egg incubation period are required to further investigate stranding rates and whether operations affect egg and larval survival below Revelstoke Dam.

4.3 Management Question 4: What is the most effective method for monitoring spawning of White Sturgeon?

Previous studies have shown the most effective method for monitoring White Sturgeon spawning in the middle Columbia River appears to be a combination of egg mat and larval drift net sampling. Other methods for monitoring White Sturgeon spawning in this area have included sonic telemetry and DIDSON monitoring (Golder 2009, Crossman et al. 2011). Though these methods were effective for observing sturgeon in the spawning area, they were ineffective methods for spawning monitoring.

In 2012, eggs and free embryos were only collected in larval drift nets, which may have been a function of the high discharge levels that precluded effective sampling with egg mats in the thalweg. Egg mats have been the most consistent method for monitoring White Sturgeon spawning below REV since monitoring began in 1999. However, additional larval drift net sampling in upcoming years may help determine whether one of these two methods is most effective.

4.4 Management Question 5: Can modifications be made to operations of Revelstoke Dam and ALR to protect or enhance White Sturgeon incubation habitat?

Physical conditions at the White Sturgeon spawning area have varied substantially over the years that spawning monitoring has occurred below REV. The REV discharge regime, along



with ALR elevation, influence the physical conditions (depth, velocity and thermal regime) observed at the spawning area. No correlations have been identified between these physical conditions and observations of spawning below REV (Golder 2012a). Flow modifications associated with the addition of REV5 changed the operational regime observed at the spawning grounds beginning during the 2011 spawning season. Additional information is being collected to investigate the influence of REV operations and ALR elevation on White Sturgeon spawning habitat.

White Sturgeon spawning below REV is the latest known to occur within the range of the species (Parsley et al. 2011). Parsley et al (2011) found that White Sturgeon eggs hatched under a cool thermal regime similar to that observed below REV hatched later, were shorter at hatch and developed slower than those hatched under a warm thermal regime similar to conditions mimicking those of the lower Columbia River at the international border. Though eggs and free embryos are captured regularly downstream of REV, natural recruitment to juvenile life stages has not been observed. Late spawn timing and the cool water temperature regime in the middle Columbia River have been hypothesized to result in reduced condition of early life stages of White Sturgeon (Parsley et al. 2011).

Water temperature below REV is influenced by the conditions within the REV forebay (i.e. thermal stratification) as outlet gates generally release cooler, hypolimnetic water while spill gates draw warmer, epilimnetic water from the reservoir surface during the spawning period (Bray 2012). The time periods that the largest hourly fluctuations in temperature were observed at the spawning area (maximum of 0.8 °C) all occurred within two to four hours of the onset or cessation of spill gate use at REV. This observation may indicate that the source of REV forebay water (epilimnetic or hypolimnetic) can influence thermal conditions at the spawning area. Characterization and quantification of the thermal regime of the REV forebay is ongoing and the results could be used to determine if allocation of warmer, surface water could increase water temperatures at the spawning grounds (Bray 2012).

The discharge capacity and operational regime observed in the middle Columbia River changed with the installation of a fifth turbine at REV in December 2010 (Section 4.2). Initial observations suggest flow modifications since the installation of REV5 have increased REV peak discharge and increased the total wetted riverbed area (Golder 2012b). These physical modifications have likely reduced the potential dewatering of incubating White Sturgeon eggs; no eggs were observed during one stranding survey conducted during a low flow event in early September 2011 and no low flow events occurring during the incubation period in 2012. Future stranding surveys during low flow events following spawning observations will help clarify if the current operational regime has mitigated potential dewatering of incubation areas.

The water temperature regime may also have been altered over the spawning area following the addition of REV5. Water temperatures observed at the spawning area in 2011 were within a narrower range over the spawning period than what had been observed during previous sampling years (4.5 °C as opposed to ranges between 5.1 °C and 8.6 °C; Golder 2012a). In 2012, the range was slightly higher but at the lower end of what has been observed in previous years (5.3 °C). Information collected under CLBMON-27 could provide



insight into whether a narrow temperature range throughout the spawning period influences the incubation of White Sturgeon eggs.

The influence of REV operations and ALR elevation on physical conditions observed at the spawning area is being identified during concurrent BC Hydro WUP programs. Data has been collected during other studies in the same area, including CLBMON-20 (Mid Columbia River White Sturgeon Spawning Habitat Assessment), CLBMON-27 (Mid Columbia River Sturgeon Incubation and Rearing Study) and CLBMON-54 (Mid Columbia River Effects of Flow Changes on Incubation and Early Rearing Sturgeon). Upon completion of these programs, a detailed review of the physical conditions over the spawning area (discharge, thermal regime and substrate) compared with what is known on White Sturgeon spawning habitat requirements elsewhere could provide insight into potential modifications to REV operations to protect or enhance spawning habitat.

5.0 ASSESSMENT OF METHODS Modifications to the previous sampling regime were required in 2012 due to extreme high water conditions in the White Sturgeon spawning area below Revelstoke Dam. The study program started 7 to 10 days later than in previous years and mid-channel sampling was not possible until the latter portion of the study period due to high discharges. As a result, less effort was expended on egg mat sampling, especially at mid-channel locations. However, as recommended in Golder (2012a), larval drift net sampling was increased in 2012 and was successful at capturing both White Sturgeon free embryos and one egg. Larval drift nets were generally set on only one day each week, which reduced the temporal coverage of this effort compared to previous years. Overnight larval drift net sets were not a feasible means of increasing effort as the debris load over that period rendered the nets ineffective. This can be readdressed in the future if water conditions permit.



6.0 RECOMMENDATIONS The following are recommendations for the 2013 White Sturgeon spawn monitoring program.

1. Continue to focus sampling effort at the sturgeon spawning area adjacent to the Revelstoke Golf Course in the middle Columbia River (Km 228.4 to Km 229.9). Significant sampling effort expended since 1999 have identified this as the predominant incubation area.

2. Commence the 2013 sampling program in the fourth week of July and continue sampling through early September; high water levels delayed sampling until August 1, 2012. Spawning events have been documented between July 25 and August 28 in the middle Columbia River (Golder 2012a).

3. Continue to deploy egg collection mats at both near shore and mid-channel locations in the White Sturgeon spawning area. Effort expended at mid-channel locations was limited in 2012 due to the high discharge observed at the spawning area. In addition, near shore sets should be weighted to extend the distance they are set from the shore line.

4. Split larval drift net sampling in the White Sturgeon spawning area between both field days each week. Larval drift net sampling effort was higher in 2012 than in previous years though drift net sampling was predominantly conducted on only one day each week. Larval drift net sampling effort could be increased by sampling on both field days each week. Effort in overnight drift net sets may be possible when conditions are not as extreme those observed in 2012.



7.0 REFERENCES

BC Hydro 2012. Columbia River Project Water Use Plan Monitoring Program Terms of Reference. CLBMON-23 Mid Columbia River White Sturgeon Spawn Monitoring.

Bray, K. 2012. Kinbasket and Revelstoke reservoirs ecological productivity monitoring. Progress report Year 3 (2010). BC Hydro, Environment. Study No. CLBMON-3. 4pp. + appendices.

Crossman, J. A., Martel, G., Johnson, P. N. and Bray, K. 2011. The use of dual-frequency identification sonar (DIDSON) to document white sturgeon activity in the Columbia River, Canada. Journal of Applied Ichthyology 27: 53-57.

Dettlaff, T.A., A.S. Ginsburg and O.I. Schmalhausen. 1993. Sturgeon fishes. Developmental biology and aquaculture. Springer-Verlag, Berlin, Germany, 300 pp.

Golder Associates Ltd. 2006. A synthesis of White Sturgeon investigations in Arrow Lakes Reservoir, B.C. 1995 – 2003. Report prepared for BC Hydro, Castlegar, B.C. Golder Report No. 041480016F: 61 p. + plates + 11 app.

Golder Associates Ltd. 2008. Middle Columbia River White Sturgeon spawn monitoring: 2007 investigations data report. Report prepared for BC Hydro, Revelstoke, B.C. Golder Report No. 07-1480-0053F: 12 p. + plates + 2 app.

Golder Associates Ltd. 2009. Middle Columbia River White Sturgeon spawn monitoring: 2008 investigations data report. Report prepared for BC Hydro, Revelstoke, B.C. Golder Report No. 08-1480-0029F: 24 p. + 2 app.

Golder Associates Ltd. 2010. Middle Columbia River White Sturgeon spawn monitoring: 2009 investigations data report. Report prepared for BC Hydro, Castlegar, B.C. Golder Report No. 09-1480-0040F: 20 p. + 2 app.

Golder Associates Ltd. 2011. Middle Columbia River White Sturgeon spawn monitoring: 2010 investigations. Report prepared for BC Hydro, Castlegar, B.C. Golder Report No. 10-1492-0061F: 17 p. + 1 app.

Golder Associates Ltd. 2012a. Middle Columbia River White Sturgeon spawn monitoring: 2011 investigations. Report prepared for BC Hydro, Castlegar, B.C. Golder Report No. 11-1492-0071F: 21 p. + 1 app.

Golder Associates Ltd. 2012b. Middle Columbia River physical habitat monitoring. CLBMON-15a. Annual technical report – 2011. Report prepared for BC Hydro, Castlegar, BC. Golder Report No. 11-1492-0084. 44 p. + 6 app.

Johnson, P. N., M.H. Tiley, S. LeBourdais and R.C. Bocking. 2009. Monitoring Study No. CLBMON-23b. Mid-Columbia River White Sturgeon underwater videography feasibility study 2008-2009 final Report.

McCabe, G.T., and L.G. Beckman. 1990. Use of an artificial substrate sampler to collect white sturgeon eggs. California Fish and Game 76:248–250.



National Recovery Team for White Sturgeon (NRT). 2010. Recovery strategy for White Sturgeon (Acipenser transmontanus) in Canada. In Species at Risk Act Recovery Strategy Series. Ottawa: Fisheries and Oceans Canada. 249 pp.

Parsley, M.J., L.G. Beckman & G.T. McCabe, Jr. 1993. Spawning and rearing habitat use by white sturgeons in the Columbia River downstream from McNary Dam. Transactions of the American Fisheries Society 122: 217-227.

Parsley, M.J., E. Kofoot, and T.J. Blubaugh. 2011. Mid Columbia Sturgeon Incubation and Rearing Study (Year 2 – 2010). Report prepared for BC Hydro, Castlegar, B.C. 23 p + 1 app.

Porto, L. 2008. White Sturgeon populations in the BC Hydro dam footprint impacts area. Report prepared for the Columbia Basin Fish and Wildlife Program, Columbia Basin, Nelson, BC. 45 p. + 1 app.

R.L. & L. Environmental Services Ltd. 2000. White sturgeon investigations in Arrow Reservoir and Columbia River, B.C., 1999 study results. Report prepared for B.C. Ministry of Environment, Lands and Parks, Nelson, B.C. R.L. & L. Report No. 754F: 38 p. + 4 app.

Tiley, M. 2005. White Sturgeon larval and juvenile development and survival reared under fall and early winter Revelstoke Reach temperature conditions. Final Summary Report, March 2005. Prepared for the Endangered Species Recovery Fund.

Upper Columbia River White Sturgeon Recovery Initiative (UCRWSRI). 2002. Upper Columbia White Sturgeon Recovery Plan. 90 pp.

Wang, Y.L., F.P. Binkowski and S.I. Doroshov. 1985. Effect of temperature on early development of white and lake sturgeon, Acipenser transmontanus and A. fulvescens. Environ. Biol. Fishes.



APPENDIX A Egg Collection Mat Sampling

Date (2012) Time

Water Temp (°C)

Date (2012) Time

Water Temp (°C)

Eggs Free Embryos

CPUE Eggs

229.0L 4.0 Aug. 01 13:45 10.6 Aug. 09 18:03 10.9 196:18 196.3 0 0 0

229.4L 6.0 Aug. 01 13:52 10.6 Aug. 09 18:29 10.9 196:37 196.62 0 0 0

228.65M 5.5 Aug. 10 16:25 11.6 Aug. 17 12:49 12.0 164:24 164.4 0 0 0

229.0L 4.5 Aug. 10 14:30 11.9 Aug. 17 10:54 12.0 164:24 164.4 0 0 0

229.1L 5.4 Aug. 10 15:28 11.8 Aug. 16 17:55 12.0 146:27 146.45 0 0 0

229.45L 4.0 Aug. 10 10:40 11.8 Aug. 16 18:08 11.9 151:28 151.47 0 0 0

229.4L 4.2 Aug. 10 14:34 11.9 Aug. 17 10:28 4.7 163:54 163.9 0 0 0

229.6L 5.2 Aug. 10 11:40 11.8 Aug. 16 18:18 11.9 150:38 150.63 0 0 0

229.7L 6.5 Aug. 10 11:54 11.8 Aug. 16 18:34 11.8 150:40 150.67 0 0 0

229.9L 3.3 Aug. 10 12:08 11.8 Aug. 16 18:49 11.8 150:41 150.68 0 0 0

229.1L 4.2 Aug. 16 17:55 12.0 Aug. 22 15:30 11.2 141:35 141.58 0 0 0

229.45L 3.8 Aug. 16 18:08 11.9 Aug. 22 15:56 11.2 141:48 141.8 0 0 0

229.6L 3.1 Aug. 16 18:18 11.9 Aug. 22 16:12 11.2 141:54 141.9 0 0 0

229.7L 4.0 Aug. 16 18:34 11.8 Aug. 17 11:16 11.9 16:42 16.7 0 0 0

229.9L 2.3 Aug. 16 18:49 11.8 Aug. 17 11:33 11.9 16:44 16.73 0 0 0

228.75L 5.6 Aug. 17 14:41 12.0 Aug. 23 10:41 10.9 140:00 140 0 0 0

228.7M 4.0 Aug. 17 14:46 12.0 Aug. 23 10:10 10.9 139:24 139.4 0 0 0

Table A1. Egg collection mat sampling data collected during middle Columbia River White Sturgeon spawning monitoring, August 1 to September 12, 2012

Station Name

Total Time

Hours of

Effort

WSG Catch Summary1Set

Depth (m)

Set Data Pull Data

229.0L 4.1 Aug. 17 13:41 11.8 Aug. 23 9:32 10.9 139:51 139.85 0 0 0

229.4L 4.4 Aug. 17 13:16 11.8 Aug. 23 9:51 10.9 140:35 140.58 0 0 0

229.7L 4.1 Aug. 17 13:58 12.0 Aug. 22 16:03 11.2 122:05 122.08 0 0 0

229.9L 2.4 Aug. 17 14:14 11.8 Aug. 22 16:20 11.1 122:06 122.1 0 0 0

228.0L 2.8 Aug. 22 17:00 11.1 Aug. 23 9:20 10.9 16:20 16.33 0 0 0

229.1L 4.3 Aug. 22 15:35 11.2 Aug. 29 16:05 11.6 168:30 168.5 0 0 0

229.45L 4.0 Aug. 22 15:56 11.2 Aug. 29 16:43 11.7 168:47 168.78 0 0 0

229.6L 3.1 Aug. 22 16:12 11.2 Aug. 29 16:51 11.7 168:39 168.65 0 0 0

229.7L 4.2 Aug. 22 16:05 11.2 Aug. 29 17:01 11.7 168:56 168.93 0 0 0

229.9L 2.3 Aug. 22 16:20 11.1 Aug. 29 17:15 11.7 168:55 168.92 0 0 0

228.0L 3.3 Aug. 23 12:30 11.0 Aug. 30 9:06 11.2 164:36 164.6 0 0 0

228.75L 4.1 Aug. 23 10:41 10.9 Aug. 29 15:55 12.0 149:14 149.23 0 0 0

228.7M 2.3 Aug. 23 11:34 11.0 Aug. 30 9:23 11.3 165:49 165.82 0 0 0

229.0L 3.7 Aug. 23 12:37 11.0 Aug. 30 10:00 11.3 165:23 165.38 0 0 0

229.1M 5.1 Aug. 23 13:36 11.1 Aug. 29 16:18 11.8 146:42 146.7 0 0 0

229.2L 2.8 Aug. 23 13:11 10.9 Aug. 29 16:35 11.7 147:24 147.4 0 0 0

Date (2012) Time

Water Temp (°C)

Date (2012) Time

Water Temp (°C)

Eggs Free Embryos

CPUE Eggs

Station Name

Total Time

Hours of

Effort

WSG Catch Summary1Set

Depth (m)

Set Data Pull Data

229.4L 4.4 Aug. 23 12:56 11.0 Aug. 30 10:14 11.2 165:18 165.3 0 0 0

228.75L 3.7 Aug. 29 15:55 12.0 Aug. 30 9:23 11.3 17:28 17.47 0 0 0

229.1L 3.9 Aug. 29 16:05 11.6 Sep. 05 14:48 10.9 166:43 166.72 0 0 0

229.1M 4.8 Aug. 29 16:18 11.8 Sep. 05 14:40 11.0 166:22 166.37 0 0 0

229.2L 1.6 Aug. 29 16:35 11.7 Sep. 06 10:05 11.8 185:30 185.5 0 0 0

229.45L 3.3 Aug. 29 16:43 11.7 Sep. 05 15:06 11.0 166:23 166.38 0 0 0

229.6L 2.6 Aug. 29 16:51 11.7 Aug. 30 10:24 11.2 17:33 17.55 0 0 0

229.7L 2.7 Aug. 29 17:01 11.7 Sep. 05 15:29 11.1 166:28 166.47 0 0 0

229.9L 1.5 Aug. 29 17:15 11.7 Sep. 06 10:38 11.9 185:23 185.38 0 0 0

228.0L 3.5 Aug. 30 12:15 11.4 Sep. 05 13:56 11.0 145:41 145.68 0 0 0

228.75L 3.6 Aug. 30 13:40 11.4 Sep. 06 9:45 12.0 164:05 164.08 0 0 0

228.7M 2.4 Aug. 30 9:23 11.3 Sep. 05 14:04 11.0 148:41 148.68 0 0 0

229.0L 3.4 Aug. 30 12:50 11.3 Sep. 05 14:17 10.9 145:27 145.45 0 0 0

229.4L 3.8 Aug. 30 13:10 11.4 Sep. 06 10:25 11.9 165:15 165.25 0 0 0

229.6L 2.7 Aug. 30 13:25 11.4 Sep. 05 15:19 11.1 145:54 145.9 0 0 0

228.0L 2.1 Sep. 05 13:56 11.0 Sep. 12 13:42 10.9 167:46 167.77 0 0 0

228.7M 1.6 Sep. 05 14:04 11.0 Sep. 12 16:10 10.6 170:06 170.1 0 0 0

229.0L 2.3 Sep. 05 14:17 10.9 Sep. 06 9:50 12.0 19:33 19.55 0 0 0

229 1L 3 5 Sep 05 14:48 10 9 Sep 12 15:04 10 7 168:16 168 27 0 0 0229.1L 3.5 Sep. 05 14:48 10.9 Sep. 12 15:04 10.7 168:16 168.27 0 0 0

229.1M 4.7 Sep. 05 14:40 11.0 Sep. 12 15:15 10.6 168:35 168.58 0 0 0

229.45L 3.0 Sep. 05 15:14 11.0 Sep. 12 14:44 10.6 167:30 167.5 0 0 0

229.6L 2.1 Sep. 05 15:25 11.1 Sep. 12 14:35 10.7 167:10 167.17 0 0 0

229.7L 3.1 Sep. 05 15:38 11.2 Sep. 12 14:13 10.7 166:35 166.58 0 0 0

228.75L 2.8 Sep. 06 11:55 12.1 Sep. 12 16:13 10.6 148:18 148.3 0 0 0

229.0L 2.8 Sep. 06 13:05 11.7 Sep. 12 13:55 10.7 144:50 144.83 0 0 0

229.2L 1.7 Sep. 06 13:20 12.3 Sep. 12 14:53 10.7 145:33 145.55 0 0 0

229.4L 3.5 Sep. 06 13:37 12.4 Sep. 12 14:02 10.7 144:25 144.42 0 0 0

229.9L 2.1 Sep. 06 13:45 12.4 Sep. 12 14:18 10.7 144:33 144.55 0 0 01 WSG = White Sturgeon; CPUE = Catch per Unit Effort (no. eggs/hour of effort)



APPENDIX B Drift Net Sampling

D t Water W ater F CPUE CPUE F

CPUE E

CPUE Free Station Set

Depth

Set Data Pull DataEstimated

Volume S l d

White Sturgeon Catch Summary1

Total Hours of

Table B1. D-Ring larval drift net sampling data collected during middle Columbia River White Sturgeon spawning monitoring, August 1 to September 12, 2012.

Date (2012) Time

ateTemp (°C)

Date Timeate

Temp (°C)

Eggs Free Embryos

CPUE Eggs

(No./hr)

Free Embryos (No./hr)

Eggs (No./ 100

m3)

Embryos (No./ 100

m3)229.0L 4.0 1-Aug 11:27 10.6 1-Aug 13:45 10.6 2:18 2.3 -a 0 0 0 0 -a -a

a a a

Name Depth (m)

Sampled (m3)

Time of Effort

229.4L 6.0 1-Aug 11:40 10.6 1-Aug 13:52 10.6 2:12 2.2 -a 1 0 0.45 0 -a -a

229.0L 3.5 9-Aug 18:24 10.8 10-Aug 9:40 11.8 15:16 15.27 -b 0 0 0 0 -b -b

229.4L 3.4 9-Aug 18:30 10.8 10-Aug 10:40 11.8 16:10 16.17 -b 0 0 0 0 -b -b

228 7L 5 0 10 Aug 9:20 11 8 10 Aug 13:10 11 8 3:50 3 83 3182 0 2 0 0 52 0 0 016228.7L 5.0 10-Aug 9:20 11.8 10-Aug 13:10 11.8 3:50 3.83 3182 0 2 0 0.52 0 0.016

229.0L 4.5 10-Aug 9:39 11.8 10-Aug 14:30 11.9 4:51 4.85 3182 0 0 0 0 0 0

229.4L 4.2 10-Aug 10:43 11.8 10-Aug 14:34 11.9 3:51 3.85 3182 0 0 0 0 0 0

229.0L 4.4 17-Aug 10:54 12.0 17-Aug 13:41 11.8 2:47 2.78 3326 0 0 0 0 0 0229.0L 4.4 17 Aug 10:54 12.0 17 Aug 13:41 11.8 2:47 2.78 3326 0 0 0 0 0 0

229.4L 4.7 17-Aug 10:28 12.0 17-Aug 13:16 11.8 2:48 2.8 4295 0 2 0 0.71 0 0.017

229.7L 3.6 17-Aug 11:16 11.9 17-Aug 13:58 11.8 2:42 2.7 1617 0 1 0 0.37 0 0.023

229.9L 1.8 17-Aug 11:33 11.9 17-Aug 14:14 11.8 2:41 2.68 1617 0 2 0 0.75 0 0.046

228.0L 2.2 23-Aug 9:20 10.9 23-Aug 12:12 11.0 2:52 2.87 1548 0 0 0 0 0 0

229.0L 2.8 23-Aug 9:32 10.9 23-Aug 12:37 11.0 3:05 3.08 1278 0 0 0 0 0 0

229.2L 1.5 23-Aug 10:30 10.9 23-Aug 13:11 10.9 2:41 2.68 3622 0 0 0 0 0 0

229.4L 3.7 23-Aug 9:51 10.9 23-Aug 12:56 11.0 3:05 3.08 5036 0 0 0 0 0 0

Date (2012) Time

Water Temp (°C)

Date TimeWater Temp (°C)

Eggs Free Embryos

CPUE Eggs

(No./hr)

CPUE Free

Embryos (N /h )

CPUE Eggs

(No./ 100 3

CPUE Free

Embryos (No./ 100

Station Name

Set Depth

(m)

Set Data Pull DataEstimated

Volume Sampled

(m3)

White Sturgeon Catch Summary1

Total Time

Hours of

Effort( C) ( C) (No./hr) (No./hr) m3)

(m3)

228.0L 1.8 30-Aug 9:06 11.2 30-Aug 12:15 11.4 3:09 3.15 3045 0 0 0 0 0 0

228.75L 3.3 30-Aug 9:37 11.3 30-Aug 9:48 11.3 0:11 0.18 393 0 0 0 0 0 0

229 0L 3 4 30 Aug 10:00 11 3 30 Aug 12:50 11 3 2:50 2 83 4027 0 0 0 0 0 0229.0L 3.4 30-Aug 10:00 11.3 30-Aug 12:50 11.3 2:50 2.83 4027 0 0 0 0 0 0

229.4L 3.6 30-Aug 10:14 11.2 30-Aug 13:10 11.4 2:56 2.93 5683 0 0 0 0 0 0

229.6L 1.1 30-Aug 10:25 11.2 30-Aug 13:25 11.4 3:00 3 4418 0 0 0 0 0 0

229 0L 2 7 6-Sep 9:50 12 0 6-Sep 13:05 11 7 3:15 3 25 3343 0 0 0 0 0 0229.0L 2.7 6 Sep 9:50 12.0 6 Sep 13:05 11.7 3:15 3.25 3343 0 0 0 0 0 0

229.2L 1.5 6-Sep 10:11 11.8 6-Sep 13:20 12.3 3:09 3.15 6069 0 0 0 0 0 0

229.4L 3.5 6-Sep 10:25 11.9 6-Sep 13:36 12.4 3:11 3.18 6276 0 0 0 0 0 0

229.9L 1.1 6-Sep 10:38 11.9 6-Sep 13:45 12.4 3:07 3.12 3313 0 0 0 0 0 0p p

228.0L 1.9 12-Sep 13:44 10.9 12-Sep 16:28 10.5 2:44 2.73 2993 0 0 0 0 0 0

229.0L 3.1 12-Sep 13:56 10.7 12-Sep 16:40 10.1 2:44 2.73 2542 0 0 0 0 0 0

229.4L 2.7 12-Sep 14:03 10.7 12-Sep 16:43 10.1 2:40 2.67 3834 0 0 0 0 0 0

229.7L 3.2 12-Sep 14:14 10.7 12-Sep 17:00 10.5 2:46 2.77 1072 0 0 0 0 0 01 CPUE = Catch per Unit Effort (number of eggs or free embryos / hour of effort or 100 m3 of water sampled).a Velocity meters not used during these sets.b Drift nets set overnight and velocity meter readings could not be determined as meters zero'ed themselves an unknown number of times.



APPENDIX C Station Location Coordinates

Zone Easting Northing229.0L 11 U 413406 5651850229.4L 11 U 413688 5651999

229.45L 11 U 413737 5652038229.6L 11 U 413861 5652130229.7L 11 U 413956 5652204229.9L 11 U 414156 5652323

228.65M 11 U 413229 5651560229.1L 11 U 413469 5651860228.7M 11 U 413261 5651594228.0L 11 U 413451 5651377229.2L 11 U 413569 5651923229.1M 11 U 413430 5651908228.75L 11 U 413268 5651613

UTM CoordinatesStation Name

Table C1. UTM coordinates of sample locations during White Sturgeon spawning monitoring in the middle Columbia River, 2012.

Columbia River Project Water Use Plan Columbia White ... · 4/30/2013 · Columbia River Project...

Documents

Transcript of Columbia River Project Water Use Plan Columbia White ... · 4/30/2013 · Columbia River Project...