HILL CREEK SPAWNING CHANNELADULT KOKANEE ENUMERATION

REPORT 2003

PREPARED BYGrant Thorp, Harvey Andrusak, Allison Alder

November 2003

COLUMBIA BASINFISH & WILDLIFECOMPENSATION

PROGRAM

www.cbfishwildlife.org

Hill Creek Spawning Channel

Adult Kokanee Enumeration Report – 2003

by

Grant Thorp1, Harvey Andrusak2, Allison Alder1,

for

Columbia Basin Fish and Wildlife Compensation Program#103 – 333 Victoria Street

Nelson, BC V1L 4K3

1 Hailstorm Ridge Environmental Services, PO Box 93 Nakusp, BC V0G 1R02 Redfish Consulting Ltd. 5244 Highway 3A Nelson, B.C. V1L 4K3

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Executive Summary

Hill Creek Spawning Channel Adult Kokanee Enumeration Report - 2003

This report reviews and summarizes 2003 kokanee (Onchorychus nerka) datacollected from the Hill Creek Spawning Channel (HCSC). This summary is partof a long term data set that tracks the performance of the kokanee compensationprogram on the Arrow Reservoir. The HCSC is the principal kokanee productioncenter for the entire Upper Arrow Reservoir.

The HCSC was completed in 1980 as partial compensation for the loss ofspawning habitat incurred as a result of the Revelstoke dam constructed on theupper Columbia River 2 km north of Revelstoke BC. The channel, locatedapproximately 68 km north of Nakusp (Fig. 1), is 3.2km in length and 6.1m inwidth and was designed to provide quality spawning habitat for approximately150,000 kokanee. The design criteria and specific biophysical description of thechannel are described by Lindsay (1982) and is shown in Figure 2. Sincechannel operations began in 1980 there has been on-going evaluation(s) ofkokanee spawners and subsequent fry production resulting in development of agood time series data set.

The 2003 migration of kokanee spawners into Hill Creek commenced on August22nd and by September 21st some 155,826 adult kokanee had been enumerated.The number of spawners in the HCSC was 133,951 with the remainder (21,875)distributed in the natural portion of Hill Creek below the channel. Enumerationwas conducted predominantly at two permanent fence sites, fence 3 located atthe lower end of the spawning channel and fence 4 located at the intersection ofHill Creek with Hill Creek Road. The 2003 escapement was slightly lower thanexpected most likely because of a shift in age-at-maturity of the progenyproduced in 2000.

Sampling was conducted throughout the spawning run to monitor variousbiological parameters required to estimate egg deposition and ensure continuityfor the comprehensive time-series database. Mean spawner length (21.4 cm),weight (107 g) and fecundity (233) all decreased in 2003 compared to the resultsfor the previous three years escapements Egg retention estimates and male tofemale ratios were consistent with the historical records.

The HCSC provides a key index of kokanee abundance within the ArrowReservoir and provides important data required for monitoring and assessing theon-going Arrow Reservoir Fertilization program.

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Table of Contents

Executive Summary ............................................................................................................ i

Table of Contents ............................................................................................................... ii

List of Figures ................................................................................................................... iii

1.0 Introduction............................................................................................................ 1

2.0 Methods .................................................................................................................. 12.1 Enumeration Methods ........................................................................................ 1

2.2 Sampling Methods............................................................................................... 2

3.0 Results .................................................................................................................... 43.1 Total Estimated Return ...................................................................................... 5

3.2 Channel Enumeration......................................................................................... 5

3.3 Adult Sampling Data........................................................................................... 6

3.4 Egg Deposition Estimates ................................................................................... 63.4.1 HCSC Egg Deposition Estimates ............................................................................. 63.4.2 Fence #4 to HCSC (Fence #3).................................................................................. 63.4.3 Fence #4 downstream to Galena Bay ....................................................................... 7

3.5 Fry Production Estimates - 2004........................................................................ 73.5.1 HCSC Fry Production Estimates .............................................................................. 73.5.2 Fence #4 to HCSC (Fence #3).................................................................................. 73.5.3 Fence #4 downstream to Galena Bay ....................................................................... 7

3.6 Adult Projections - 2007...................................................................................... 8

4.0 Discussion .............................................................................................................. 8

5.0 Recommendations ................................................................................................ 10

6.0 Acknowledgements............................................................................................... 10

7.0 References ............................................................................................................ 10

8.0 Appendix............................................................................................................... 12Appendix 1: Daily Escapement Estimates – Fence #4................................................ 12

Appendix 2: Daily Escapement Totals – Channel ...................................................... 13

Appendix 3: 2003 Sampling Data for Adult Spawners .............................................. 14

Appendix 4: Egg Retention Data ................................................................................. 19

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List of Figures

Figure 1: Hill Creek Spawning Channel Location 3

Figure 2: Hill Creek Spawning Channel Site Plan 4

Figure 3: Hill Creek Spawning Channel Returns 1977-2003 5

Figure 4: Hill Creek Spawning Channel Egg- Adult Survival 9

Figure 5. HCSC Adult Kokanee Size at Return 10

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1.0 Introduction

The Arrow Reservoir was formed from the Upper and Lower Arrow Lakes by completionof the Hugh Kennleyside Dam in 1967. Arrow Reservoir is part of the Columbia Riverwith two dams located upstream, Revelstoke (1984) and Mica (1973). The onlyassessment of Arrow Lakes sport fish losses prior to dam construction was conductedby Martin (1976) who estimated annual losses due to Revelstoke Dam were probably4,000 bull trout (Salvelinus confluentus), 1,000 rainbow (Onchorychus mykiss) and500,000 kokanee (Onchorychus nerka). The Hill Creek spawning channel wasconstructed to offset the loss of the 0.5 million kokanee and an experimental hatcherywas built later at Hill Creek to compensate for trout and char losses due to impacts of allthree dams (Kennleyside, Revelstoke and Mica Dams). A more detailed description offish losses and the compensation program are described by Pieters et al. (1998).

The Hill Creek spawning channel operations and maintenance are funded by acompensation program jointly established by the provincial government and BC Hydro.The Columbia Basin Fish and Wildlife Compensation Program (CBFWCP) providesfunding and oversees fish and wildlife compensation work throughout the Canadianportion of the Columbia basin.

This report describes the 2003 adult kokanee enumeration program at HCSC along withresults and comparisons with previous historical data. Operational components includeadult kokanee enumeration and biological sampling of spawning kokanee that typicallyare present from late August through to mid October. Kokanee are the keystonespecies for the Arrow Reservoir therefore monitoring their abundance is crucial to theunderstanding of the reservoirs’ current status particularly in view of the Reservoirfertilization program that began in 1999.

2.0 Methods

Various standard sampling protocols are consistently employed to determine specificbiological parameters required to measure channel performance. The rationale forbiological sampling, standard sampling procedures and the details of the physicalcharacteristics of the channel has been described by Redfish Consulting Ltd. (1999).Some additional measurements are made at Hill Creek for daily enumeration andpopulation management purposes and these are described as follows:

2.1 Enumeration Methods

Manual counts were done by visually enumerating up-streaming kokaneepassage through a custom fabricated, inverted “V” aluminum enumerator. APulsar® Model 550C resistivity fish counter was also used, in conjunction withmanual counts, to electronically record upstream fish passage.

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The Pulsar® counter uses conductivity as the primary method of measuring fishpassage through a series of tunnel banks. Each tunnel bank is composed of 4counting and one reference tunnel, each with a series of 5 imbedded electroderings. The reference tunnel is blocked and acts only to update and monitorconductivity in order to provide a benchmark for the counting banks. Thecounting tunnels are bi-directional (i.e. up-stream and/or down-stream) and onlyrecord a complete up-stream or down-stream count once a fish has completelycleared the opposite end from which it entered.

Daily enumerations for kokanee entering Hill Creek at the lower counting fence(Fence #4) were accomplished through manual and electronic methods.Enumeration estimates for kokanee entering the spawning channel were doneexclusively through manual counts (Appendix 2). Adult enumeration, at bothsites, commenced August 22nd and was complete by September 22nd.

2.2 Sampling Methods

Spawners are sampled at two locations on the channel throughout the duration ofthe run with the samples assumed to be representative of the whole. A typicalrandom sample of 10-30 fish is collected periodically throughout the course of thespawn run at Fence # 4 for purposes of determining length, weight, fecundity,sex ratio and otolith analysis (Appendix 3). Post-spawner egg retention samples(Appendix 4) are collected at random within the spawning channel and again, areassumed to be representative.

Samples collected at the Fence #4 location were measured for fork length andweighed on an Ohaus® Model 2100 portable electronic field balance. Allfemales were eviscerated to determine egg retention information and otolithswere extracted from a random sub-sample for ageing purposes.

The information collected from these samples is used primarily to:• estimate potential egg deposition• generate fry production approximations the following spring• generate future adult return projections and,• monitor channel performance.

Potential egg deposition is calculated using the following formula:

Pe = Fs x (f – r) x Pa

Ts

where; Pe = potential egg depositionFs = # females in total samplef = mean fecundityr = mean retentionPa = number of fish in a known populated areaTs = total number of fish sampled

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Figure 1. Hill Creek Spawning Channel Location

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Figure 2. Hill Creek Spawning Channel Site Plan

3.0 Results

An estimated total of 155,826 kokanee returned to spawn in Hill Creek for 2003 ofwhich, 133,951 fish spawned in the channel (Fig. 3).

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HCSC Adult Returns 1977-2003

-

50,000

100,000

150,000

200,000

250,000

300,000

350,000

19771981

19851989

19931997

2001

Year

# A

dults

ChannelTotal Return

Figure. 3 Hill Creek Spawning Channel Returns 1977-2003

3.1 Total Estimated Return

The 2003 total estimated adult kokanee return to Hill Creek was 155,826 with themajority enumerated primarily between August 22nd and September 22nd

(Appendix 1). Peak day for counting was August 30th when an estimated 20,053adults were enumerated through Fence #4 representing approximately 13% ofthe total.

A visual estimate of the number of spawners utilizing the natural creek down-stream of Fence # 4 to the confluence with Galena Bay/Upper Arrow) wasconducted on September 22nd. An estimated total of 3,715 kokanee werecounted and this number is included as part of the overall escapement estimate.

A further 21,875 kokanee were estimated to be utilizing Hill Creek betweenFence #4 and #3.

3.2 Channel Enumeration

The total estimated adult kokanee enumerated into HCSC in 2003 (133,951)occurred primarily between August 28th and September 22nd (Appendix 2). Thepercentage of the return population enumerated into HCSC represented 86% ofthe total.

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3.3 Adult Sampling Data

A total of 237 samples were collected and analyzed in 2003 (Appendix 3). Arandom sub-set collection of 111 samples were taken for future otolith/ageinganalysis and are highlighted in italics within Appendix 3. An additional 124samples were collected chiefly within HCSC to determine egg retention and areshown in Appendix 4. Samples were taken at various times throughout theenumeration and post-spawning process, are assumed to be statisticallyrepresentative and provide the following data:

• mean fork length of 21.4 cm• fork length range of 17.3 – 38.4 cm• mean weight of 107 g• weight range of 54 – 650 g• mean fecundity of 233 eggs/female• fecundity range of 129 – 1,272• mean egg retention was 9 eggs/female• egg retention range was 0 - 144

3.4 Egg Deposition Estimates

Based on the enumeration and sample results in 2003, it is estimated that adultreturns to Hill Creek generated a total green-egg deposition of approximately16.7 million. This estimate takes into account egg retention and represents thesum of three distinct areas in the system. i.e. channel, the stream betweenfences # 3 and 4 and the stream below Fence #4.

3.4.1 HCSC Egg Deposition Estimates

Based on the enumeration and sampling results identified in the precedingsections, the egg deposition estimate for HCSC is 14,432,796 and wascalculated as follows:

133,951 x 114 x (233 – 9) = 14,432,796237

3.4.2 Fence #4 to HCSC (Fence #3)

Based on the enumeration and sampling results identified in the precedingsections, the egg deposition estimate for this section was 1,897,745 andwas calculated as follows:

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17,613 x 114 x (233 – 9) = 1,897,745237

3.4.3 Fence #4 downstream to Galena Bay

Based on the enumeration and sampling results identified in the precedingsections, the egg deposition estimate for this section is 400,279 and wascalculated as follows:

3,715 x 114 x (233 – 9) = 400,279237

3.5 Fry Production Estimates - 2004

A forward-looking prediction is provided of what the 2004 fry production shouldbe based on twenty years of measured egg-to-fry survival rates. Assumingaverage survival rates occur during 2003-2004, the total fry production in 2004 isestimated to be 4.44 million.

3.5.1 HCSC Fry Production Estimates

Assuming a green-egg survival rate of 30% for adults spawning in HCSCand based on egg deposition estimates (shown in the previous section)the estimated fry production in 2004 should be 4.32 million calculated asfollows:

14,432,796 (egg est.) x 30% (assumed survival rate) = 4,329,839

3.5.2 Fence #4 to HCSC (Fence #3)

Assuming a green-egg survival rate of 5% for adults spawning in HillCreek proper and based on egg deposition estimates (shown in theprevious section) the estimated fry production in 2004 should be 94,887calculated as follows:

1,897,745 (egg est.) x 5% (assumed survival rate) = 94,887

3.5.3 Fence #4 downstream to Galena Bay

Assuming a green-egg survival rate of 5% for adults spawning in HillCreek proper and based on egg deposition estimates (shown in theprevious section) the estimated fry production in 2004 should be 20,014calculated as follows:

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400,279 (egg deposition estimate) x 5% (assumed survival rate) = 20,014

3.6 Adult Projections - 2007

Adult projections provide forward-looking information and are generally shown asa rough approximation and guidance tool only. Based on that premise as well ashistorical survival rates, the estimated adult spawner returns in 2007 are 222,237calculated as follows:

4,444,740 (est. fry production) x 5% (assumed fry to adult survival) = 222,237

Since kokanee fry spend 2 or 3 years in the reservoir immediately followingemergence, all generated fry projections and subsequent adult returns to HillCreek are assumed to be equal.

4.0 Discussion

The overall timing of the adult kokanee spawner return to Hill Creek in 2003 appearedto be consistent with historical data however, the initial peak and secondary “wave”materialized much earlier than typically experienced (Thorp, G.N., et al. UnpublishedM.S. reports 1984-2001). Run timing did not appear to be delayed or adversely affectedby the warmest, driest summer weather experienced in B.C. in nearly 75 years(http://www.climate.weatheroffice.ec.gc.ca/advanceSearch/searchHistoricDataStations_e.html).

Spawner escapement to Hill Creek in 2003 was less than anticipated. Based on fryenumeration conducted at HCSC in 1999 (Thorp, G.N. 1999), it was expected thatapproximately 220,000 adult kokanee would return to spawn in the fall of 2003 based onan assumed 5% fry-to-adult survival rate. The actual return of 155,826 represents a 4%fry to adult survival rate, slightly lower than the 5% used to forecast the 2003 return (Fig.4). Andrusak (2002) suggested that a shift in age at maturity occurred in 2002 with 50%of the spawners returning at age 2+ rather than age 3+. He speculated that this shiftwas most likely due to a density growth response since this cohort grew in the lakewhen total numbers were very low. i.e. during 1998-2000 when kokanee numbers werelow but fertilization began. It follows then that the 2003 return would be lower thanforecast since half of them spawned a year earlier.

The lake carrying capacity has been increased due to lake fertilization but it is expectedthat a new equilibrium level will soon be reached given the large numbers of fryproduced from HCSC over the last four years. The age data from the 2003 spawnerswill be most informative since the majority of these fish may have already shifted backto age 3+.

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HCSC Egg-Adult Survival

0

2

4

6

8

10

12

14

16

1977 1980 1983 1986 1989 1992 1995 1998 2001

Year

% S

urvi

val

% Survival

Figure 4. Hill Creek Spawning Channel Egg-Adult Survival Rate

Mean spawner size in 2003 was marginally larger than in 2002. The dramatic decreasein size experienced in the last two years follows equally substantial increased in sizeduring the late 1990s that coincided with reduced numbers in the lake and start up oflake fertilization. The recent erratic size of Hill Creek spawners should soon even outand a more discernible pattern re-establish once the longer-term effects of thefertilization program on survival rates and in-lake population densities stabilizes.Historical size data for kokanee returning to spawn at HCSC is shown in Figure 5The current field procedures and techniques employed at HCSC are based on aconsistent and systematic approach to enumeration and sampling regime. There arenumerous technologies which could be used to obtain a higher degree of accuracy butfor the level of management applied to Arrow Reservoir fisheries the current methodsand techniques are quite acceptable. Hill Creek spawning channel operations and thedata derived from the monitoring program represent the single most important kokaneeescapement dataset available for Arrow Lakes Reservoir.

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HCSC Spawner Size at Return

200

220

240

260

280

300

320

19771980

19831986

19891992

19951998

2001

Year

Mea

n Fo

rk L

engt

h (c

m)

Fork Length

Figure 5. HCSC Adult Kokanee Size at Return

5.0 Recommendations

• Continue to monitor kokanee spawner utilization of the HCSC• Ensure that age at maturity is determined for the 2003 spawners• Continue to record basic biological data such as length at maturity, fecundity and

egg retention.• Continue to estimate egg deposition so that egg-to-fry survival rates can be

determined• Replace damaged/missing weir timbers in channel• Replenish spawning-grade gravel at channel

6.0 Acknowledgements

The authors acknowledge the assistance of Harald Manson (CBFWCP) and ColinSpence (WLAP) for their efforts in providing review and comments.

7.0 References

Andrusak, H. 2002 Response of Arrow Reservoir Kokanee to ExperimentalFertilization in 2001 Redfish Consulting Ltd Contract Report for the ColumbiaBasin Fish and Wildlife Compensation Program Nelson BC

Lindsay, R.A., 1976 Restoration and Enhancement Opportunities on the ArrowReservoir (Northern Natural Resources Ltd.). Unpublished M.S., BC Fish

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Wildlife Branch, Nelson BC, 68p

Lindsay, R.A., 2002 Physical & Biological Criteria Used in the Design of the HillCreek Spawning Channel. Unpublished M.S., BC Fish and Wildlife Branch,Nelson BC, 22p

Martin, A.D., 1976 Interim Report of Investigation of Fish Populations that will beaffected by the Revelstoke 1880 Dam. Unpublished M.S., BC Fish and WildlifeBranch, Nelson BC, 48p

Pieters, Roger, Lisa C. Thompson, Lidija Vidmanic, Meghan Roushorne, JohnStockner,Ken Hall, Mark Young, Steve Pond, Ken Ashley, Bob Lindsay, GregLawrence,

Harvey Andrusak, Dale Sebastian, George Scholten. 2000. Arrow ReservoirFertilization Year 1 (1999/2000) Report. Fisheries Project Report No. RD 82.Province of BC, Ministry of Environment, Lands and Parks.

Redfish Consulting Ltd. 1999 Performance Evaluation of Six Kokanee SpawningChannels in British Columbia. Unpublished M.S. Ministry of Fisheries,Province of British Columbia Victoria BC.

Thorp, G.N., 1999 Hill Creek Spawning Channel Kokanee Fry Enumeration Report in1999. Unpublished M.S. Ministry of Environment, Province of BC Nelson BC12p.

Thorp, G.N., Millar, B. 2002. Hill Creek Spawning Channel Adult Kokanee Enumeration Report for 2002. Unpublished M.S. Ministry of Water, Land and

Air Protection, Nelson BC.

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8.0 Appendix

Appendix 1: Daily Escapement Estimates – Fence #4

Date Daily Cumulativedd mm yy Total Total

20 8 2003 - -21 8 2003 -22 8 2003 18 1823 8 2003 6 2424 8 2003 242 26625 8 2003 181 44726 8 2003 34 48127 8 2003 403 88428 8 2003 1,092 1,97629 8 2003 7,360 9,33630 8 2003 20,053 29,38931 8 2003 9,193 38,582

1 9 2003 9,025 47,6072 9 2003 6,053 53,6603 9 2003 5,810 59,4704 9 2003 10,054 69,5245 9 2003 10,697 80,2216 9 2003 8,757 88,9787 9 2003 15,981 104,9598 9 2003 15,172 120,1319 9 2003 3,925 124,056

10 9 2003 3,546 127,60211 9 2003 4,660 132,26212 9 2003 8,441 140,70313 9 2003 3,148 143,85114 9 2003 2,050 145,90115 9 2003 1,675 147,57616 9 2003 1,043 148,61917 9 2003 1,549 150,16818 9 2003 782 150,95019 9 2003 212 151,16220 9 2003 284 151,44621 9 2003 106 151,55222 9 2003 12 151,56423 9 2003 Fence #4 Removed 151,564*

*An estimated 3,715 kokanee were visually estimated to be spawning in Hill Creek between Fence#4 and Galena Bay (Upper Arrow Reservoir) on September 22nd, 2003. This brings the totalestimated escapement to 155,279.

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Appendix 2: Daily Escapement Totals – Channel

Date Daily Cumulativedd mm yy Total Total23 8 2003 1 124 8 2003 - 125 8 2003 1 226 8 2003 - 227 8 2003 - 228 8 2003 8 1029 8 2003 19 2930 8 2003 12,729 12,75831 8 2003 11,128 23,8861 9 2003 7,513 31,3992 9 2003 8,008 39,4073 9 2003 4,952 44,3594 9 2003 11,481 55,8405 9 2003 14,651 70,4916 9 2003 8,227 78,7187 9 2003 4,054 82,7728 9 2003 7,852 90,6249 9 2003 10,719 101,343

10 9 2003 2,509 103,85211 9 2003 1,653 105,50512 9 2003 5,220 110,72513 9 2003 9,436 120,16114 9 2003 2,929 123,09015 9 2003 871 123,96116 9 2003 1,913 125,87417 9 2003 2,350 128,22418 9 2003 2,418 130,64219 9 2003 1,244 131,88620 9 2003 1,475 133,36121 9 2003 471 133,83222 9 2003 119 133,95125 9 2003 Fence #3 removed 133,951

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Appendix 3: 2003 Sampling Data for Adult Spawners

Sample Date Sex Length Weight Fecundity#* YY MM DD (mm) Mean (g) Mean #/ Mean1 2003 8 27 M 274 2302 2003 8 27 M 268 2203 2003 8 27 F 287 225 5414 2003 8 27 M 217 945 2003 8 27 M 222 1026 2003 8 27 M 243 1357 2003 8 27 M 221 1048 2003 8 27 M 211 969 2003 8 27 M 218 96

10 2003 8 27 M 254 16011 2003 8 27 M 225 11412 2003 8 27 M 209 8613 2003 8 27 M 203 9014 2003 8 27 M 220 234 98 132 54115 2003 8 29 F 227 116 28016 2003 8 29 M 212 9017 2003 8 29 F 202 84 24818 2003 8 29 M 220 10819 2003 8 29 M 208 10220 2003 8 29 M 210 10421 2003 8 29 M 215 11422 2003 8 29 M 225 11423 2003 8 29 F 212 90 17224 2003 8 29 M 208 9225 2003 8 29 F 220 102 24526 2003 8 29 M 207 10227 2003 8 29 M 207 9628 2003 8 29 M 220 10629 2003 8 29 M 218 10430 2003 8 29 F 211 104 16231 2003 8 29 F 211 96 25832 2003 8 29 M 203 10033 2003 8 29 M 216 10234 2003 8 29 M 230 14535 2003 8 29 M 212 222 110 238 26836 2003 8 30 F 222 112 24837 2003 8 30 M 218 12038 2003 8 30 F 225 110 26439 2003 8 30 M 203 9040 2003 8 30 M 240 14041 2003 8 30 M 227 12642 2003 8 30 M 230 14043 2003 8 30 M 218 12644 2003 8 30 M 221 13045 2003 8 30 M 225 12246 2003 8 30 M 207 10047 2003 8 30 M 200 104

- 15 -

48 2003 8 30 M 198 9649 2003 8 30 M 217 10650 2003 8 30 F 200 87 19251 2003 8 30 M 228 13052 2003 8 30 M 207 10453 2003 8 30 M 197 9254 2003 8 30 M 211 10655 2003 8 30 F 199 78 15356 2003 8 30 F 203 87 16357 2003 8 30 M 222 10858 2003 8 30 F 213 104 20759 2003 8 30 M 173 6460 2003 8 30 F 205 88 14361 2003 8 30 F 213 106 23262 2003 8 30 F 210 218 98 111 214 23363 2003 8 31 M 217 10664 2003 8 31 M 221 11065 2003 8 31 M 218 11266 2003 8 31 F 208 92 17867 2003 8 31 M 220 11868 2003 8 31 M 193 8069 2003 8 31 M 225 12270 2003 8 31 M 219 11871 2003 8 31 M 192 7672 2003 8 31 M 220 12473 2003 8 31 M 214 10274 2003 8 31 F 192 68 12975 2003 8 31 M 210 10476 2003 8 31 F 200 78 17377 2003 8 31 F 211 98 31078 2003 8 31 F 201 80 19979 2003 8 31 M 210 10480 2003 8 31 M 218 11681 2003 8 31 F 213 98 28382 2003 8 31 F 203 88 14483 2003 8 31 M 205 10484 2003 8 31 M 210 10285 2003 8 31 F 189 215 72 108 163 22286 2003 9 1 F 221 110 31587 2003 9 1 F 229 135 25488 2003 9 1 M 212 11289 2003 9 1 M 216 10290 2003 9 1 M 205 9891 2003 9 1 M 237 15592 2003 9 1 M 216 11293 2003 9 1 M 218 11294 2003 9 1 M 217 11095 2003 9 1 F 230 117 36496 2003 9 1 M 207 9497 2003 9 1 M 207 9098 2003 9 1 F 206 92 22499 2003 9 1 M 206 90100 2003 9 1 F 197 80 215101 2003 9 1 F 208 90 136

- 16 -

102 2003 9 1 F 212 100 290103 2003 9 1 F 192 78 176104 2003 9 1 M 206 85105 2003 9 1 F 204 90 288106 2003 9 1 F 204 215 86 107 214 229107 2003 9 1 M 212 118108 2003 9 1 M 220 120109 2003 9 1 M 208 108110 2003 9 1 M 244 155111 2003 9 1 M 227 118112 2003 9 1 M 210 94113 2003 9 1 M 210 99114 2003 9 1 M 204 90115 2003 9 1 M 213 114116 2003 9 1 F 210 96 200117 2003 9 1 F 203 94 201118 2003 9 1 M 213 117119 2003 9 1 F 204 96 159120 2003 9 1 M 205 102121 2003 9 1 M 202 94122 2003 9 1 M 211 110123 2003 9 1 F 217 112 251124 2003 9 1 F 204 92 217125 2003 9 1 M 210 108126 2003 9 1 M 198 84127 2003 9 1 F 216 106 285128 2003 9 1 M 198 90129 2003 9 1 F 199 92 269130 2003 9 1 M 202 214 100 106 229131 2003 9 5 M 356 450132 2003 9 5 M 358 490133 2003 9 5 F 216 96 220134 2003 9 5 M 215 110135 2003 9 5 M 201 78136 2003 9 5 M 200 92137 2003 9 5 M 213 90138 2003 9 5 M 202 88139 2003 9 5 M 254 150140 2003 9 5 F 197 76 217141 2003 9 5 M 215 104142 2003 9 5 M 214 96143 2003 9 5 M 216 104144 2003 9 5 M 215 112145 2003 9 5 M 189 66146 2003 9 5 F 222 108 214147 2003 9 5 F 206 90 208148 2003 9 5 M 211 98149 2003 9 5 F 214 102 171150 2003 9 5 M 217 216 102 110 226151 2003 9 6 M 224 135152 2003 9 6 M 225 140153 2003 9 6 F 234 122 312154 2003 9 6 M 215 106155 2003 9 6 M 212 104

- 17 -

156 2003 9 6 F 220 100 307157 2003 9 6 M 212 98158 2003 9 6 F 202 86 233159 2003 9 6 M 216 116160 2003 9 6 F 206 94 206161 2003 9 6 F 183 60 197162 2003 9 6 F 218 104 223163 2003 9 6 M 225 104164 2003 9 6 M 192 74165 2003 9 6 F 205 90 236166 2003 9 6 F 206 88 251167 2003 9 6 F 201 86 212168 2003 9 6 F 216 100 266169 2003 9 6 F 203 94 220170 2003 9 6 M 217 116171 2003 9 6 F 216 108 247172 2003 9 6 M 208 96173 2003 9 6 F 210 92 161174 2003 9 6 F 210 94 152175 2003 9 6 F 202 86 244176 2003 9 6 F 198 78 208177 2003 9 6 F 205 86 218178 2003 9 6 M 198 88179 2003 9 6 F 181 62 184180 2003 9 6 F 185 214 64 108 218 226181 2003 9 7 F 210 88 257182 2003 9 7 M 226 140183 2003 9 7 M 207 98184 2003 9 7 F 203 82 226185 2003 9 7 M 207 104186 2003 9 7 F 212 104 279187 2003 9 7 F 204 90 153188 2003 9 7 F 242 130 256189 2003 9 7 M 210 88190 2003 9 7 F 204 78 182191 2003 9 7 M 211 96192 2003 9 7 F 180 62 195193 2003 9 7 F 228 116 329194 2003 9 7 F 206 88 173195 2003 9 7 F 219 106 223196 2003 9 7 F 201 80 154197 2003 9 7 F 217 98 288198 2003 9 7 F 208 92 193199 2003 9 7 F 205 96 200200 2003 9 7 F 215 102 266201 2003 9 7 F 207 99 249202 2003 9 7 F 193 78 161203 2003 9 7 F 208 93 222204 2003 9 7 F 177 54 149205 2003 9 7 F 205 88 198206 2003 9 7 F 210 92 228207 2003 9 7 F 213 100 231208 2003 9 7 F 205 212 94 104 204 220209 2003 9 12 F 384 650 1272

- 18 -

210 2003 9 12 F 213 88 262211 2003 9 12 M 196 94212 2003 9 12 F 208 80 199213 2003 9 12 M 202 104214 2003 9 12 F 209 90 204215 2003 9 12 F 212 88 208216 2003 9 12 F 207 86 213217 2003 9 12 F 205 88 217218 2003 9 12 F 214 98 236219 2003 9 12 F 198 84 237220 2003 9 12 M 226 130221 2003 9 12 F 211 98 246222 2003 9 12 F 224 106 308223 2003 9 12 F 203 88 179224 2003 9 12 F 191 72 167225 2003 9 12 F 218 98 257226 2003 9 12 F 211 94 139227 2003 9 12 F 207 88 242228 2003 9 12 F 182 214 66 107 218 233229 2003 9 18 F 212 98 234230 2003 9 18 F 219 104 249231 2003 9 18 F 208 90 209232 2003 9 18 F 222 108 214233 2003 9 18 F 206 92 224234 2003 9 18 F 192 80 186235 2003 9 18 F 203 88 221236 2003 9 18 F 197 86 219237 2003 9 18 F 224 214 110 107 292 233

*Samples shown in italics had otoliths removed for ageing purposes

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Appendix 4: 2003 Egg Retention Data

Date # of Egg RetentionSamples Range Mean

September 18 13 0 - 28 10September 20 21 0 - 144 11September 22 26 0 - 72 12September 24 27 0 - 63 11September 29 21 0 - 31 9October 2 17 0 - 65 9

Total 124 0 - 144 9