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Canadian Manuscript Report of

Fisheries and Aquatic Sciences 2224

1993

REPORT OF THE ARCTIC FISHERIES

SCIENTIFIC ADVISORY COMMITTEE

FOR 1991/92 AND 1992/93

by

S.E. Cosens, R. Crawford, B.G.E. de March and T.A. Shortt

Central and Arctic Region

Department of Fisheries and Oceans

Winnipeg, Manitoba R3T 2N6

This is the 33rd Manuscript Report

from the Central and Arctic Region, Winnipeg

ii

© Minister of Supply and Services Canada 1993Cat. no. Fs 97-410000E ISSN 0706-6473

Correct citation for this publication is:

S.E. Cosens, R. Crawford, B.G.E. de March and T.A. Shortt. 1993. Report of the Arctic FisheriesScientific Advisory Committee for 1991/92 and 1992/93. Can. Manuscr. Rep. Fish. Aquat.Sci. 2224: iv + 51 p.

iii

TABLE OF CONTENTS

Page

ABSTRACT/RÉSUMÉ . . . . . . . . . . . . . . . . . . . . iv

OVERVIEW OF THE ARCTIC FISHERIESSCIENTIFIC ADVISORY COMMITTEE . . . 1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1AFSAC membership . . . . . . . . . . . . . . . . . . . . . . . 1AFSAC activities . . . . . . . . . . . . . . . . . . . . . . . . . . 2General results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2General conclusions . . . . . . . . . . . . . . . . . . . . . . . . 3

REPORT OF THE AFSAC MARINE MAMMALSUBCOMMITTEE: 1991/92 . . . . . . . . . . . . . 3

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3High Arctic Narwhal . . . . . . . . . . . . . . . . . . . . . . . 3Southeast Baffin Beluga . . . . . . . . . . . . . . . . . . . . . 7

REPORT OF THE AFSAC MARINE MAMMALSUBCOMMITTEE: 1992/93 . . . . . . . . . . . . . 8

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Harp Seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Southeast Baffin Beluga . . . . . . . . . . . . . . . . . . . . 11Sub-Arctic Walrus . . . . . . . . . . . . . . . . . . . . . . . . 12Marine Mammal Research Plan . . . . . . . . . . . . . . 13

REPORT OF THE AFSAC FISH SUBCOMMITTEE: 1991/92 . . . . . . . . . . . . 14

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Lake Whitefish - Great Slave Lake . . . . . . . . . . . 15Arctic Charr - Sylvia Grinnell River . . . . . . . . . . 16Arctic Charr - Ikaluit River . . . . . . . . . . . . . . . . . 17Arctic Charr - Diana River . . . . . . . . . . . . . . . . . . 17Quota Recommendations: Commercial fish-

eries of anadromous Arctic charr,Northwest Territories - 1992/93 . . . . . . . . . . 18

REPORT OF THE AFSAC FISHSUBCOMMITTEE: 1992/93 . . . . . . . . . . . . . . . . 19Arctic Charr - Kuujjua River . . . . . . . . . . . . . . . . 19Arctic Charr in Freshwater Creek, Northwest

Territories . . . . . . . . . . . . . . . . . . . . . . . . . . . 21The Great Slave Lake Commercial Inconnu,

Stenodus leucichthys, Fishery . . . . . . . . . . . . 23Quota Recommendations for Commercial Fish-

eries in Anadromous Arctic Charr, North-west Territories, 1993/94 . . . . . . . . . . . . . . . . 25

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . 26

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . 26

LIST OF TABLESTable Page

1 1991/92, 1992/93 quotas andharvest and 1993/94 recommendedquotas for the anadromousArctic charr commercialfisheries in the NorthwestTerritories . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

LIST OF TABLES (cont’d)

Table Page

2 Recommended changes to commercialfishing quotas for anadromousArctic charr in the NorthwestTerritories 1992/93 and/or1993/94 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3 Comparison of data required formanaging marine mammals on thebasis of replacement yield . . . . . . . . . . . . . . . 36

LIST OF FIGURES

Figure Page

1 Geographic key to locationsdescribed in the stock reports . . . . . . . . . . . . 37

LIST OF APPENDICES

Appendix Page

1 List of AFSAC background docu-ments for 1991/92 and 1992/93 . . . . . . . . . . . 38

2 List of AFSAC background docu-ments by species, 1986 to1990/91 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3 Glossary of terms used in thereport by the Marine MammalSubcommittee for 1991/92 and1992/93 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

4 Glossary of terms used in thereport by the Fish Subcommitteefor 1991/92 and 1992/93 . . . . . . . . . . . . . . . . 50

iv

ABSTRACT

S.E. Cosens, R. Crawford, B.G.E. de March and T.A. Shortt. 1993. Report of the Arctic FisheriesScientific Advisory Committee for 1991/92 and 1992/93. Can. Manuscr. Rep. Fish. Aquat. Sci.2224: iv + 51 p.

The Arctic Fisheries Scientific Advisory Committee (AFSAC) was established in November1985 to develop and provide scientifically sound advice for stocks of fish and marine mammals inthe Northwest Territories, Yukon north slope and other territorial waters managed by the Centraland Arctic Region of the Department of Fisheries and Oceans. AFSAC is comprised of aChairperson, Executive Committee, Fish Subcommittee and Marine Mammals Subcommittee;operates on the peer review principle; reports to the Regional Director, Science, and advises theRegional Director General and Regional Director, Fisheries and Habitat Management. In 1991/92and 1992/93, AFSAC reviewed and developed advice on 7 fish stocks/stock complexes, annualcommercial quotas for Arctic charr in the NWT and four marine mammal stocks.

Key words: Arctic zone; fish; management; marine mammals; research; stocks.

RESUME

S.E. Cosens, R. Crawford, B.G.E. de March and T.A. Shortt. 1993. Report of the Arctic Fisheries Scientific Advisory Committee for 1991/92 and 1992/93. Can. Manuscr. Rep. Fish. Aquat. Sci.2224: iv + 51 p.

Le Comité scientifique consultatif des pêches canadiennes dans l’Arctique (CSCPCA) a été crééen novembre 1985 dans le but d’étudier de manière rigoureusement scientifique les stocks depoissons et de mammifères marins des Territoires du Nord-Ouest, du versant nord du Yukon et deseaux territoriales gérées par la Région du Centre et de l’Arctique. Le CSCPCA est composé d’unprésident, d’un comité exécutif, d’un sous-comité des poissons et d’ un sous-comité desmammifères marins; il fonctionne selon le principe de révision par les pairs, rend compte de sesactivités au Directeur régional des sciences et conseille le Directeur général régional et le Directeurrégional du service de Gestion des pêches et de l’habitat. En 1991/92 et 1992/93, le CSCPCA aexamine sept complexes stocks de poissons et quatre stocks de mammifères marins ainsi que sur lesquotas commerciaux annuels de l’omble chevalier, et fait des recommandations à leur égard.

Mots-clés: zone de l’Arctique; poisson; gestion; mammifère marins; programmes derecherche; stocks.

1

OVERVIEW OF THE ARCTIC FISHERIESSCIENTIFIC ADVISORY COMMITTEE:

1991/92 and 1992/93

INTRODUCTION

Since its establishment as a regional scientificadvisory body in November, 1985, the ArcticFisheries Scientific Advisory Committee (AFSAC)has provided management advice and researchrecommendations on a large number of Arctic speciesand stocks (See Appendix 2). AFSAC’s mainobjective, as originally described in 1985, continuesto be to provide sound biological advice to FisheriesManagement (the Regional Director General andRegional Director of Fisheries and HabitatManagement for the Central and Arctic Region) onArctic fish and marine mammal stocks so thatmanagement decisions result in the long-term well-being of these stocks. AFSAC has provided advice tofishery management boards and to Departmentalfishery managers to guide in the formulation ofmanagement decisions. Using a peer review principle,AFSAC ensures the scientific quality and biologicalsoundness of the advice which it provides.

In addition to management advice. AFSACidentifies, for Science managers, researchrequirements for the various stocks/species for whichthe Department is responsible in the Canadian Arctic.

According to the Terms of Reference andOperating Procedures April, 1987. the specificresponsibilities of AFSAC are:

a) to assess the status of fish and marine mammalstocks and to make biologically soundrecommendations on harvest levels;

b) to assess other biological aspects of manage-ment (such as size restrictions, closed seasons,mesh size, etc.) and to make biologically soundrecommendations on such operationalrequirements for management;

c) to assess the adequacy of biological informationavailable for making fisheries managementdecisions and to make recommendations for itsextension or improvement;

d) to review and assess biological aspects of generalmanagement plans for fish and marine mammals:and

e) to respond to any other request for biologicaladvice on fisheries management and habitatissues from the Director General. RegionalDirector of Fisheries and Habitat Management,Regional Director of Science, Central and ArcticRegion, as may from time to time arise.

In 1988, an AFSAC coordinator based inWinnipeg, was established and AFSAC broadened itsscope of involvement in Arctic management issues byincluding the Quebec Region.

To aid its work, AFSAC commissions thepreparation of background reports on specific topics;these are internal working documents solely for theuse of AFSAC members. A schedule for review ofimportant fish and marine mammal stocks isestablished in consultation with the RegionalDirector, Fisheries and Habitat Management and theRegional Director, Science. A list of backgrounddocuments used by the subcommittees in their1991/92 and 1992/93 reviews is provided asAppendix 1.

AFSAC MEMBERSHIP

AFSAC discharges its responsibilities throughthe activities of its Chairperson, Coordinator,Executive Committee, Fish Subcommittee andMarine Mammals Subcommittee. The majority ofmembers are from the Central and Arctic Region,Department of Fisheries and Oceans (DFO). but theQuebec Region, DFO. was represented as well - Themembership of AFSAC during 1991/92 and 1992/93was:

Executive Committee

R. McV. Clarke (Fisheries and HabitatManagement, Central andArctic Region)

T.A. Shortt (Science, Central and ArcticRegion) AFSAC Coordinatorand Chairperson

S. Cosens (Science, Central and ArcticRegion)

R. Crawford (Science, Central and ArcticRegion) 01/04/91 - 06/92

B.G.E. de March (Science, Central and ArcticRegion) 09/92 - 31/03/93

S. Labonté (Science, Quebec Region09/92 - 31/03/93)

Fish Subcommittee

R. Crawford (Science, Central and ArcticRegion) Chairperson 1991/92only

B.G.E. de March (Science, Central and ArcticRegion) Chairperson 1992/93only

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E. Gyselman (Science, Central and ArcticRegion) 1991/92 only

A. Kristofferson (F&HM, Central and ArcticRegion) 1991/92 only

J. Flannagan (Science, Central and ArcticRegion)

G. Low (F&HM, Yellowknife, Centraland Arctic Region) 1992/93only

D. Bodaly (Science, Central and ArcticRegion)

J. Lambert (Science, Quebec Region)1992/93 only

Marine Mammals Subcommittee

S. Cosens (Science, Central and ArcticRegion) Chairperson

S. Innes (Science, Central and ArcticRegion)

P. Richard (F&HM, Central and ArcticRegion)

T. Strong (F&HM, Central and ArcticRegion)

R. Stewart (Science, Central and ArcticRegion)

H. Cleator (Science, Central and ArcticRegion)

M. Kingsley (Science, Quebec Region)1992/93 only

During 1991/92 and 1992/93 a number ofchanges were made to the AFSAC committees.

Dr. R. Crawford vacated his position asChairperson of the Fish Subcommittee in May, 1992when he left the Department to assume a researchposition in the U.S.A. He was replaced by Dr. B.G.E.de March, a newly appointed member of the FishSubcommittee in September, 1992. G. Low. fisherymanagement biologist, South/Central Arctic Area forFisheries and Habitat Management in Central andArctic Region was appointed as a member of the FishSubcommittee for 1992/93. J. Lambert from Sciencein Quebec Region was appointed to thatSubcommittee for 1992/93.

Minimal changes occurred in the MarineMammal Subcommittee in 1991/92 and 1992/93. Dr.S. Cosens served as Chairperson and M. Kingsleyrepresented Science in Quebec Region for 1992/93.

The Executive Committee membershipunderwent some changes as well. In 1991/92, M.Papst, Science, Central and Arctic Region, resignedfrom the Executive Committee due to hisappointment to the Fisheries Joint ManagementCommittee (FJMC). In 1992/93 S. Labonté, Director,Biological Sciences for the Quebec Region joined theExecutive Committee. The Chairpersons of theSubcommittees also serve on the ExecutiveCommittee, so the changes in the Chairperson of theFish Subcommittee were also reflected in theExecutive Committee.

AFSAC ACTIVITIES

During 1991/92 AFSAC reviewed eightbackground documents including the annual report onharvests and quota recommendations for commercialfisheries of anadromous Arctic charr in the NorthwestTerritories and a report on the results of a 1991beluga survey in Clearwater Fjord. The AFSACbackground reports on fish stocks/species werereviewed at the Winnipeg meeting of the FishSubcommittee on March 9-10, 1992. In addition, thatyear, the Fish Subcommittee provided a definition ofconservation in response to a request from the officeof the Assistant Deputy Minister of Science for DFO.The Marine Mammals Subcommittee held its meetingon March 3, 1992. That Subcommittee also examineda definition of conservation offered by CanadianAtlantic Fisheries Scientific Advisory Committee(CAFSAC) and provided comments on its applicationto the management of Arctic stocks. As well, inFebruary, 1992, the Marine Mammals Subcommitteerevised a draft COSEWIC status report on high arcticbeluga.

In 1992/93. another eight background reportswere reviewed by AFSAC. In addition to the annualreport on harvests and quota recommendations forcommercial fisheries of anadromous Arctic charr inthe Northwest Territories, reports on cliff-top surveysof whales and of biological and ecological effects ofnet fisheries for whales were also reviewed. The FishSubcommittee held its 1992/93 meeting on February2-3, 1993 in Winnipeg, while the Marine MammalsSubcommittee met on. February 17, 1993. At thosemeetings, the Subcommittees completed their reviewsof and developed their recommendations formanagement and needed research on the stocksand/or species.

In November, 1992 in Ottawa, the members ofAFSAC’s Marine Mammals Subcommittee metjointly with the Marine Mammal Subcommittee ofCAFSAC and representatives from the Pacific StockAssessment Review Committee (PSARC). At thatmeeting, a number of issues of joint interest to marinemammal scientists were discussed, as well as issuesof particular interest to each committee -

AFSAC also considered whether a HabitatScience Subcommittee should be added but decidednot to do so for the time being.

3

GENERAL RESULTS

The main results of AFSAC’s activities in1991/92 and 1992/93 continued to be thedevelopment of management recommendations andthe identification of research requirements for sevenfish stocks! stock complexes, and three marinemammal stocks. As well, quota recommendationswere revised for anadromous Arctic charr commercialfisheries in the Northwest Territories.

The use of common reporting format by theSubcommittees was continued. The basic format forreports on each stock/species is:

IntroductionBackground

Stock definitionStock sizeVital parametersCurrent harvestOther impacts

Major issuesAssessmentStock prognosis

Management recommendationsResearch requirementsNext AFSAC review

The specific recommendations from each revieware contained in the reports of the Fish Subcommitteefor 1991/92 and 1992/93, and of the MarineMammals Subcommittee for 1991/92 and 1992/93;these constitute the four major sections of this report.They include summaries of the information presentedand AFSAC’s advice on the stocks! speciesconsidered.

As was initiated in the last report, literaturecitations and references have been included. Thesewill benefit those readers seeking more informationon species being reviewed. In addition, glossaries ofterms have been developed and are included asAppendix 3 for the Marine Mammals Subcommitteeand Appendix 4 for the Fish Subcommittee. Thedefinitions contained in these glossaries are thosewhich have been accepted by the Subcommittees andapply to this report and the previous report for1989/90 and 1990/91. Future annual reports byAFSAC will also contain these glossaries.

Figure 1 has been updated for this report. Itcontains a map marked with the locations referred toin the text and will be of benefit to those unfamiliarwith some of the areas frequented by Arctic species.

GENERAL CONCLUSIONS

Overall, the Subcommittees of AFSAC continuedto agree that biological data on Arctic species are stillinadequate. Once again, it was pointed out that thereis a continuing need to collect basic biological dataon several Arctic species. particularly those in the

marine environment not previously exploited forcommercial or subsistence purposes. As well, there isa need for continuity in the collection of data, a needfor collection of accurate and uniform catch statistics.as well as for continued research on stockidentification through genetics and on recruitment. Aslong as resources for Arctic stock assessmentresearch continue to be allocated on an uncertainyear-to-year basis, the required research will be veryslow and much important work will remain undone.

REPORT OF THE AFSAC MARINE MAMMALSSUBCOMMITTEE: 1991/92

INTRODUCTION

On March 3, 1992, the Marine MammalsSubcommittee met to review two cetacean stocks: thehigh arctic narwhal and SE. Baffin beluga stock. TheSubcommittee reviewed the following backgrounddocuments:

- High Arctic Narwhal. S. Cosens. (AFSACDocument 1991/92-01):

- S.E. Baffin Beluga Stock. P. Richard (AFSACDocument 1991/92-04);

- The 1991 Clearwater Fiord Beluga Survey.- D. Pike (AFSAC Document 1991/92-07).

In addition to reviewing stocks at the meeting inMarch, the Subcommittee reviewed several reportsand documents throughout the year. In September,1991, the Subcommittee was asked to comment on adefinition of ‘conservation’ proposed by CAFSACand assess its suitability for use in management ofarctic stocks. In October, the Subcommittee reviewedthe clause, requesting a bowhead quota, proposed forthe Tungavik Federation of Nunavut land claimsagreement. For that review, Subcommittee membersresponded as individual marine mammal expertsbecause the time frame was too short to develop aSubcommittee response. Finally, in February 1992.The Subcommittee reviewed the draft COSEWICstatus report on high arctic beluga.

HIGH ARCTIC NARWHAL

Introduction

This stock was first reviewed by AFSAC in1988/89 and was recommended for re-evaluation in1992, after completion of more research (Cosens etal. 1990). Since then, one research project has beencompleted and new harvest statistics have beencollected. These two developments have resulted insufficient new information to permit a revisedassessment of the status of this stock.

Background

Stock definition: Three stocks of narwhals

4

have been tentatively identified in and around theeastern Canadian Arctic: one summering adjacent tonorthwest Greenland, one in the Canadian high Arcticarchipelago and one in northwestern Hudson Bay(Strong 1988). Hunters in Arctic Bay, however,indicate that narwhals of two different body typesmigrate through their area in the spring (Innes pers.comm.). Late migrants (July) are darker and largerthan early migrants. The implication of theseobservations for stock identification is not clear. Thehigh Arctic stock occurs in the waters and deep fiordsof the eastern Canadian archipelago during thesummer and migrates westward from Baffin Bay inthe spring and eastward in the fall through LancasterSound. Hunters in the Upernavik and Thule regionsof Greenland also catch narwhals mainly from May toAugust (Kapel 1977), suggesting that the narwhalsfound off the northwestern coast of Greenland in thesummer months could be part of the high arctic stock.The summer range may, therefore, extend from theCanadian archipelago to northwestern Greenland.

Harvest data from Greenland show that narwhalsare taken from the southwest coast only betweenNovember and May (Kapel 1977). Catches arenegligible during late spring and summer, suggestingthat whales spend only the winter there. These datasuggest that the high Arctic narwhals winter aroundDisco Bay, then move northward in early spring.

Stock size: 1984 aerial survey data (DFOunpublished data) was used to derive an estimate of17 900 (95% C.I.= 13 100 - 21 400) narwhals to bepresent in four major summer concentration areas:Eclipse Sound/ Navy Board Inlet, Admiralty Inlet,Prince Regent Inlet and Peel Sound. These data arecurrently being re-analyzed to map the distribution ofsightings and adapt the data as a stock size index. A1985 survey counted 4 000 narwhals summering inthe Thule district of Greenland (Strong 1988). If theseanimals are part of the high Arctic stock. then stocksize could number 21 900 (C.I.= 17 100 - 25 400)visible animals.

Dueck (1989) estimated that the proportion ofnarwhals visible at the water surface at any giventime averaged .38 (95% CI.= .29 - .52) during pre-break up, late break up and open water periods, andA8 (95% C.I.= .34 - .64) during the early break upperiod around Admiralty Inlet. The proportion of timethat narwhals spend resting at the surface variedamong different groups and habitats, so correctionfactors must be used with caution. Nevertheless, thedata indicate that surveys may be sighting less than50% of animals present. Thus, there could be morethan twice as many narwhals present in areas ofknown concentration than have been counted. InCanada, estimates are not available for areas outsideof known concentration areas. If the summer range ofthe stock extends to the northwest coast of Greenland,then stock size has been underestimated.

Vital parameters: Reproductive andmorphometric data were taken from Hay (1984),Weaver and Walker (1988) and Roberge and Dunn(1990). Variation around the mean is expressed asStandard Error (+/- SE).

Age at first ovulation: 50% of females begin toovulate at 12 growth layers or 6 years of age (Hay1984). Ageing methods assume that two compositegrowth layers are laid down each year. Application ofthe DeMaster method (1978) to correct for age bias inthe sample provides an estimated ‘mean age at sexualmaturity’ of 12.3 composite growth layers (Hay1984).

Fatness: This condition factor has been quantifiedby two different measures: maximum girth/bodylength and dorsal axillary blubber thickness. Themean maximum girth/body length of males rangedfrom a minimum of 0.56 +/- 0.01 (N=15) in July to amaximum of 0.65 +/- 0.01 (N=22) in August:temporal differences were statistically significant(Hay, 1984). In the same study, maximum girth! bodylength of females ranged from 0.60 +/- 0.01 (N=23)in July to 0.63 +/- 0.01 (N=36) in August: differenceswere not statistically significant. Hay (1984) foundthat this ratio varied significantly with femalereproductive status, immature females averaging 0.65+/- 0.01 and lactating females averaging 0.59 +/-0.01.

More recent studies of narwhals have notreported measurements of females or included theirreproductive status, but this should be done tofacilitate interpretation of data col1ected in differentstudies and to monitor changes in stock status.Maximum girth/body lengths of individual narwhalslanded near Arctic Bay were not calculated byRoberge and Dunn (1990). Dividing the meanmaximum girth of the total sample by mean length ofthe total sample yields a condition ratio without anestimate of variation. The ratio for males was 0.62and for females was 0.59. Similarly, ratios werecalculated for animals landed at Pond Inlet. The ratiofor males was 0.59 and for females was 0.63.

Dorsal axillary blubber thickness of malesaveraged 6.7 +/- .18 cm (N=51) in Arctic Bay(Roberge and Dunn 1990) and 6.6 +/- .59 cm (N=10)in Pond Inlet (Weaver and Walker 1988). Comparingonly adult males, Roberge and Dunn (1990) foundthat Arctic Bay males (6.6 cm +/- 0.18, N=51) weresignificantly thinner than Pond Inlet males (8.0 +/-0.37, N=9). Blubber of females landed in Arctic Bayaveraged 5.2 +/- 0.34 cm (N=19). Only one femalewas measured at Pond Inlet. Hay (1984) reportedlateral blubber thickness for females but data are notdirectly comparable to those collected from huntmonitoring studies. It has been shown that blubberthickness of females varied by reproductive state.

5

Mean body length (adults): Arctic Bay: males458 +/- 2.8 cm (N=56), females 413 +/- 7.4 cm(N=20); Pond Inlet: males 435 +/- 3.7 (N=37),females 381 +/- 6.9 (N=20). Arctic Bay animals werelarger than Pond Inlet animals (Roberge and Dunn1990). but this may reflect different hunter sizepreferences between the communities. Hay (1984)has plotted growth curves (body length againstnumber of composite tooth layers) of both males andfemales. These data eliminate hunter bias in sizeselection but require that growth layers of theembedded tusks be counted.

Modal body length: Arctic Bay: males 440 cm(N=58), females 400 cm (N=20); Pond Inlet: males425 cm (N=40), females 375 cm (N=18)

Largest body length: Arctic Bay: males 540 cm,females 480 cm; Pond Inlet: males 485 cm, females415 cm.

Finite rate of increase (er): Although Kingsley(1989) estimates r to be 3 - 4% for narwhals, otherstudies examining other odontocetes have found 2 - 3% to be the best estimate (Beland et al. 1988, Reillyand Barlow 1986).

Pregnancy rate: 38% of 79 mature females werein a state of early pregnancy (Hay 1984). Females atfull term represented 19% of mature females.

Current harvest: Annual landed harvest between1976 and 1987 averaged 248 narwhals from allCanadian locations in the summering range of thisstock (Strong 1989). In 1988, 231 narwhals wereharvested (DFO 1991) from this stock in Canada.Roberge and Dunn (1990) examined struck and lossrates of Arctic Bay hunters, considering animals thatwere mortally wounded and not landed to be lost andthose that were killed and sunk to be lost. Loss ratesaveraged 31.7% during the floe edge hunt, 23.8%during the ice crack hunt and 7.4% during the openwater hunt.

Total harvests (DFO 1991) are not distinguishedby hunt phase so an overall estimator of total removalis necessary. Averaging loss rates from Arctic Bayacross years, including struck and loss data from1990 (Dunn unpublished data). and hunt phases,yields an overall loss of 23% or an estimated kill tolanded ratio of 1.30 (defined as 1/(1-loss rate)). Lossrates do, however, vary by community. Weaver andWalker (1988) estimated loss rates to be 27 - 56% forthe floe edge, 12 - 56% for the crack and 42% for theopen water hunt at Pond Inlet. A mean struck and lossestimate, averaged for 1983, 1988 and 1990 andacross hunt types is 31% (Dunn, unpublished data).For this community, the kill:landed ratio is estimatedto be 1.45. The Arctic Bay and Pond Inlet

communities take the major portion of narwhals inCanada so loss rates for these two communities couldbe applied to estimate total removal from the stock.

Narwhals are also harvested off the west coast ofGreenland. Catches are variable, with more beingtaken in years when savssats occur. Harvests reportedby Kapel (1977) averaged 154 (SE = 24.9) narwhalsannually for west Greenland from 1963 to 1974.Since 1975, catches have averaged about 400narwhals per year (see Born 1987; Born and Kapel1986: Kapel 1982, 1983; Kapel and Larsen 1984;Larsen 1990). Total landed harvest from this stock,including both Canada and west Greenland is about648 whales annually. Applying kill:landed estimatesto these data suggest that from 842 (648 narwhals x1.30) to 940 (648 narwhals x 1.45) are removed fromthis stock each year.

Other impacts: Lancaster Sound is the onlyfeasible shipping route through the eastern Arctic andcould assume importance if the oil and gas industry inthe Arctic becomes viable or other increasedindustrial activity involving vessel traffic occurs.Narwhals are susceptible to noise disturbance fromindustrial sources (Cosens and Dueck 1988) anddevelopment in Canadian or Greenlandic waterscould affect the stock. Some communities havealready expressed concern about the effects of noisefrom shipping activity on behaviour and distributionof narwhals.

Chemical pollutants, such as heavy metals andorganochlorines may pose a potential threat (seeWagemann et al. 1983).

A growing human population, and themodernization of hunting technology, could reducethe amount of undisturbed habitat available to thestock. For example, the use of snowmobiles andpower boats permits hunters to range over a greaterarea than was once possible. This form of habitatdegradation could have a negative effect on the stock.

There is an increasing interest in commercialmarine fisheries in Arctic marine waters, particularlyfor shrimp and turbot in Davis Strait. It is conceivablethat such fisheries could adversely affect the winterfood supply of this stock.

Major Issues

Bilateral agreement: Canada and Greenland havesigned a bilateral agreement, sharing managementresponsibility for this stock. The scientific workinggroup met in 1991 to discuss and recommendresearch and management needs for narwhal -

6

Land claims: Implementation of the TungavikFederation of Nunavut (TFN) land claims agreementwill result in changes in management authority withinCanada. The Nunavut Wildlife Management Boardwill share responsibility with DFO for developing andadministering a stock management plan for narwhal.

Assessment

Stock prognosis: Using 17 900 as the estimate forstock size in Canada, total removal from this stockcould be around 1.8 to 2.0% (248 x 1.3 =) 322 to(248 x 1.45 =) 360 individuals. Given that stock sizeis probably underestimated, this level of removal isunlikely to reduce stock size. If animals from Canadaand Greenland are assumed to be from a single stock,then current removal is calculated to be from 3.8%(842/21 900) to 4.3% (940/21 900) of the total stock.

Morphometric and condition data do not suggestthat there has been a change in stock size. Conditionwould be expected to improve with a decline in stocksize. Girth/length values measured in Pond Inlet inthe mid 1970s (Hay 1984) are similar to thosemeasured in Arctic Bay in the mid-1980s (Robergeand Dunn 1990). Differences in body length andblubber thickness between Arctic Bay and Pond Inletnarwhals (Roberge and Dunn 1990) are not consistentwith a declining stock size. If stock size is declining,Arctic Bay animals should be both larger and fatter.They are larger but not necessarily in better condition.Size differences could, for example, be due todifferences in hunter experience and selectivitybetween the communities. It is also possible that thecommunities are harvesting from different stocks.

Management Recommendations

1. Guidelines for Total Allowable Removal (TAR)have been calculated under two scenarios. Stocksizes are based on animals seen at the surface andare, therefore, conservative estimates.

Scenario 1: In this case, TAR is estimated byincluding only narwhals surveyed and harvestedin Canadian waters. TAR under this scenario isestimated to range from 13 100 x .025 = 328narwhals for low risk, to 17 900 x .025 = 448 formoderate risk and 21 400 x .025 = 535 for highrisk. Current removal in Canada is considered tobe in the low risk range.

Scenario 2: In this case, the 4 000 narwhalssurveyed in the Thule Melville area of Greenlandare included as part of the high Arctic stock.TAR under this scenario is estimated to range

from 17 100 x .025 = 428 for low risk, 21 900 x .025= 548 for moderate risk and 25 400 x 025 = 635 forhigh risk removal. Current removal in both Greenlandand Canada is calculated to be 892-940 andrepresents a high risk level.

2. Morphometric and condition measurements maybe useful for assessing changes in stock status. Itis recommended that data collection from landedanimals be continued with the goal of assessingchanges in stock status due to harvesting.Refinements in data reporting should, however,be made. Data should be reported by settlementand month and include gender of landednarwhals together with reproductive status offemales.

3. Data on hunter age and experience would beuseful for testing hypotheses about communitydifferences in hunting selectivity in morphometryof landed animals, and for monitoring changes inhunting pressure and selectivity over time.

Research Requirements

1. There is a need to more clearly define narwhalstocks in and around the eastern Canadian Arcticand to examine the relationship between animalssummering in Canada and those along thenorthwest coast of Greenland. It is recommendedthat stock relationships be examined. DNAanalysis, pollution profiles, morphometrics.satellite tagging and opportunistic marking arepotential tools that should be considered. forapplication to narwhals. All previously collectedmorphometric data should be archived and re-analyzed to address questions about stockidentity and changes in stock condition. Datashould be evaluated as a basis for future datacollection and evaluated for comparability amongyears and among communities.

2. Ageing techniques should be examined. Data onages of narwhals supports stock identificationwork by permitting calculation of growth curveswhich may be of value in discriminating amongstocks. Age- at- harvest data are also useful forassessing stock status. Growth layers in tusksamples should be examined to assess whethernarwhals have two dental growth layers perannum as belugas have.

3. It would be helpful to use a measure ofconfidence for survey estimates which is moreeasily understood than the 95% ConfidenceInterval. The 1983/84 aerial survey data shouldbe re-analyzed to provide a probabil-

7

ity density distribution of abundance estimates.This function provides a visual rather thannumerical representation of confidence and maybe more acceptable to managers -

Next AFSAC Review

The next review should be made after re-analysisof the aerial survey data or. after new information onstock identity becomes available.

SOUTHEAST BAFFIN BELUGA

Introduction

This stock was last reviewed in 1988/89. Anaerial survey, made in 1986. indicated that stock sizewas declining at a significant rate. AFSACrecommended that the harvest of this stock be closedto permit recovery. Discussions between DFO and theNunavut Wildlife Advisory Management Boardresulted in a reduced 1990 quota of 5 landed belugasfor each of the communities of Pangnirtung, Iqaluitand Lake Harbour. a total of 15 whales.Disagreement between DFO and the HTAs about thetrue status of the stock then led to the formation ofthe Southeast Baffin Beluga (SEBB) Committeewhich is now responsible for making managementdecisions for this stock. At the request of thecommunities, the quota was temporarily increased byDFO in 1991 to 90 whales. At the same time, thestock was reviewed and the SEBB Committeeformulated its management and research plans.

An aerial photographic survey was carried out in1990 and cliff counts were made in 1991 providingnew data on the size and status of this stock. TheMarine Mammals Subcommittee, therefore, revisitedthe S.E. Baffin beluga stock in light of these newdata.

Background

Stock definition: This stock concentrates inCumberland Sound from late July to October andincludes animals which summer in Frobisher Bay.There is also evidence from catch records that someof these whales summer near Lake Harbour (Richard1990).

Stock size: Based on the 1985 and 1986 surveys,this stock was estimated to number about500 beluga in 1986. An aerial survey, done by DFOin 1990, counted a total of 477 belugas in ClearwaterFiord and along the south coast of CumberlandSound.

Vital parameters: Reproductive and morpho-metric data, first reported by Brodie (1971) and

Sergeant and Brodie (1969), were collected frombelugas netted in Cumberland Sound. Netting selectsfor females and calves but is not size selective.Stewart (unpubl. data) has collected the most recentinformation from hunter-killed belugas atPangnirtung. In this case, hunters select for largeanimals, so sampling is biased for males.

Age at first ovulation: Ovulation begins at amean age of 5 years. This estimate is based on theassumption that two tooth layers are deposited eachyear (Brodie 1971).

Fatness: Both girth and blubber thickness havebeen measured by Stewart (unpubl. data). Summarystatistics presented here are based on these data. Themean axillary girth/body length of males (N=26)ranged from 0.50 to 0.64. averaging 0.58 +/- 0.01.That of females (N=7) ranged from 0.48 to 0.72,averaging 0.56 +/- 0.04.

Axillary blubber thickness of males (N=24)ranged from 4.5 to 8.5 cm, averaging 6.13 +/- 0.21cm and that of females (N=5) ranged from 4.9 to 6.9cm. averaging 5.62 +/- 0.41 cm.

Mean body length: Brodie (1971) summarizeddata for whales older than 10 years: males 427 cm(N=6), females 362 cm (N=7). Stewart (unpubl. data)also has data on belugas older than 10 years: males429 cm (N=5), females 393 cm (N=2). Males olderthan 6 years of age (N=17) averaged 392 +/- 9.54 cm;females older than 5 years of age (N=5) averaged 364+/- 17.72 cm.

Modal body length: Males (N=26) 330 cm(Stewart, unpubl. data), females (N=66) 350 cm(Sergeant and Brodie 1969).

Largest body length: Males 445 cm (Brodie1967; Stewart unpubl. data), females 405 cm (Brodie1967), 395 cm (Stewart unpubl. data). A preferredmeasure is asymptotic body length determined byapplying the Von Bertalanffy growth equation tolength-at-age data. It is estimated to be 455 +/- 18.10cm for males and 399 +/- 13.82 cm for females(Stewart, unpubl. data).

Finite rate of increase et: r 2.5 % of totalpopulation (Beland et al. 1988; Reilly and Barlow1986). This estimate may be optimistic for this stock.The oldest animal recorded by Stewart (unpubl. data)was 17 years, suggesting a truncated age distributionand abbreviated reproductive period (about 12 years).Modelled population parameters may therefore beoptimistic.

Current harvest: Although AFSAC hasrecommended that no animals be removed from thisstock (Cosens et al. 1990), the Nunavut WildlifeManagement Advisory Board recommended theallowable

8

landed harvest of belugas be S for Pangnirtung, 5 forIqaluit and 5 for Lake Harbour. After furtherdiscussions with the SEBB Committee, the quotaswere revised to 35, 35 and 20 for the threecommunities respectively for both 1991 and 1992.Lake Harbour takes an unknown proportion of itssummer harvest from this stock and the quota for thiscommunity is only in effect from 1 April - 1November. Harvests in 1991 were 36 forPangnirtung, 2 for Iqaluit and 21 for Lake Harbourfor a total of 69. Assuming a rate of removal of 1.09to 1.43 times landed catch (Cosens et al. 1990), totalremoval in 1991 was 64 to 84 animals. This wouldrepresent 13.4 to 17.6 % of the stock, if current aerialsurvey counts accurately estimate stock size (=500).

Other impacts: There is potential for increasedcommercial shrimp fishing in eastern Hudson Strait,the presumed wintering area for this beluga stock(Richard 1990). Nothing is known about the winterecology of either the beluga or the shrimp, but it islikely that these whales feed on shrimp, as do belugaalong the Keewatin coast of Hudson Bay. Anexpanded commercial shrimp fishery could reducethe rate and degree of stock recovery and even furtherendanger the stock at its current low level.

Major Issues

There has been divergence of views betweenDFO and the communities about the best approach tomanagement of this stock. The Southeast BaffinBeluga (SEBB) Committee was struck in 1991 tomake management and research recommendations forthis stock.

Assessment

Stock prognosis: Counts from aerial surveys haveshown fewer than 500 animals since 1967 (see Brodie1971; Richard 1990). Although these differentsurveys are not directly comparable, they do illustratea problem with assessing the status of this stock. Astock of 500 animals cannot sustain removal of morethan 2 animals per year, yet this stock has beensubjected to much larger removals since 1967,without a decline in stock size being detected byaerial surveys. This suggests that the stock is largerthan 500 animals and must be declining more slowlythan was suspected at the time of the last AFSACreport (Cosens et al. 1990).

Cliff counts, however, do suggest that the stock isdeclining. Maximum counts, made at ClearwaterFiord, reported by Pike (unpubl - data) indicate adownward trend, from 450 belugas in 1979 to 254belugas in 1991. Richard (pers. comm.) reported 379belugas in 1984. However, data collected by different

studies are not comparable and additional data arerequired to test the hypothesis that the stock isdeclining.

Management Recommendations

1. Management goals for this stock and strategiesfor reaching them need to be defined. It isrecommended that the S.E. Baffin BelugaCommittee develop a management plan for thisstock by April, 1993.

2. The ability of this stock to sustain any level ofharvest is uncertain. It is recommended that stocksize not be allowed to fall below the currentlevel, which is a population estimate based onsightings of visible animals.


1. Stock relationships and, consequently, thegeographic range of this stock are still unknown.Morphometric data, including gender and age,should continue to be collected from all whaleslanded in Lake Harbour, Pangnirtung and Iqaluit.Data should also be collected from all whaleslanded at Southampton Island (e.g. CoralHarbour), Repulse Bay, Cape Dorset, andnorthern Quebec. Date of capture andreproductive status also should be recorded.Additional tools such as satellite telemetry, DNAanalysis and comparison of vocal signals shouldbe considered to address questions about stockidentification.

2. Growth curves and age-at-harvest data areimportant methods for discriminating amongstocks and assessing stock status. Ageingmethods must be accurate. Ageing techniquesshould be investigated to corroborate data ondental growth layers.

3. Counts of whales in Clearwater Fiord have beenmade from cliffs. Although these cliff counts maybe a useful index of stock status, methods usedby different investigators in the past are notcomparable. A cliff count of whales inClearwater Fiord should be made over a period ofone month, using methods comparable to thecount made in 1983. This count should be donein 1993.

Next AFSAC Review

The next review should be done after completionof cliff counts or when additional data, which mayclarify stock relationships, becomes available.

9

REPORT OF THE MARINE MAMMALSSUBCOMMITTEE: 1992/93

INTRODUCTION

On February 17, 1993, the Marine MammalsSubcommittee met to review three cetacean stocks:harp seals, sub-arctic walrus and S.E. Baffin belugastocks. The Subcommittee examined the followingbackground documents:

- Harp Seal (Phoca groenlandica). S. Innes.(AFSAC Document 1992/93-01);

- Summer Distribution and Abundance of Walrusin Northern Hudson Bay, Western Hudson Strait,and Foxe Basin: 1988-1990. P. Richard. (AFSACDocument 1992/93-02).

- Preliminary Report to AFSAC on the Cliff-topSurvey of Whales in Clearwater Fiord.Cumberland Sound. S. Innes. (AFSACDocument 1992/ 93-03) -

Four requests for advice were also tabled at themeeting.

1. S. Innes, a member of the S.E. Baffin BelugaCommittee, asked for opinions on a draft harvestmanagement proposal which he had prepared forthe S.E. Baffin Beluga Committee. Discussionsresulted in a redrafting of the proposal.

2. S. Cosens led discussions about developing amethod of priorizing Subcommittee researchrecommendations. Members were not inagreement about the need for priorizing researchrecommendations so no method was selected.

3. R. Stewart presented a marine mammal researchplan for discussion. The plan was developed as aguide for future activities of the Arctic MarineMammal Ecology and Assessment ResearchSection within Science of the Department ofFisheries and Ocean’s Central and Arctic Region.In light of feedback obtained at the meeting,revisions to the plan were to be made.

4. M. Breton from Fisheries and HabitatManagement in the Quebec Region hadrequested advice on the impact of using nets as aharvesting method on beluga populations. M.Kingsley prepared a background document(92/93-08) which was discussed at the meeting.A revised version of the background documentwas sent to Ms. Breton and is included in thisreport.

In addition to reviewing stocks at the meeting inFebruary, the Subcommittee met with the MarineMammals Subcommittee of CAFSAC and repre-

sentatives from PSARC in November 1992 inOttawa. An overview of research activities ongoing inCentral and Arctic Region was presented. During theportion of the meeting devoted to issues of interest toAFSAC, four papers were discussed. These includeda report on results of aerial surveys for walrus in FoxeBasin and northern Hudson Bay by P. Richard,resolving inter- observer variation in ageing walrusby R. Stewart. using cliff counts to assess the statusof the S.E. Baffin beluga stock by S. Innes and theuse of mitochondrial DNA to discriminate amongbeluga stocks by J. Clayton.

Based on discussions held on these topics, theSubcommittee concluded that the clumpeddistribution of walrus results in an imprecise estimateof stock size when using the aerial survey method.While such counts may be useful as an index, theyare inappropriate for estimating Total AllowableRemoval. In the case of the ageing walrus, inter-observer variation in counting tooth layers is similarto variation in reading aerial survey photos. Althoughinter- observer variation in age estimates has beendocumented, it would be necessary to know the trueage of the animal in order to calibrate the accuracy oftooth layer counts. The use of cliff counts of S.E.Baffin beluga appears to be useful as an index ofstock size of this specific stock. Conclusions aboutstock size trends could not be discussed becauseresults had not yet been reported to the S.E. BaffinBeluga Committee. With respect to DNA analysismethods, nucleotide sequencing is, according to thesenior scientist, the most useful technique availablefor population genetics. To date, extensive variationin gene sequences has been found in tissue samplesfrom Beaufort Sea beluga, even from samplescollected from animals within a restricted geographicarea such as the Mackenzie Delta. More samples areneeded to more clearly delineate genetic variation inthis stock.

HARP SEAL

Introduction

This stock was reviewed as a result of a requestfrom the Eastern Arctic Area office. Questions hadbeen raised about the potential effects of competitionby harp seals on ringed seals, other marine mammalsand fish. This is the first review of this stock byAFSAC.

Background

Stock definition: In Canada, the NorthwestAtlantic harp seal population is divided into twomanagement stocks: Gulf of St - Lawrence and Front(north of Newfoundland and east of Labra-

10

dor). This distinction is based on historic location ofwhelping patches, mean whelping date andexploitation history. In late spring, animals from bothstocks migrate north through Davis Strait and BaffinBay to the high Arctic waters of Canada andGreenland. Harp seals are also found in northernHudson Bay and Foxe Basin during the summer.

Stock size: Total population size is estimatedusing data on vital rates collected from harvestedanimals or derived from population simulationmodels that satisfy estimates of pup production. Roffand Bowen (1983) estimated a population size ofanimals 1 year old or older to be between 1.4 millionand 3.5 million in 1983. Current estimates arebetween 2.4 million and 4.2 million (Anon 1991).

Vital parameters: Data are taken from Bowen etal. (1981). Variation is expressed as Standard Error.

Age at first ovulation: 57 +/- 0.48 years(1950- 1959)5.4 +/- 0.31 years(1960- 1969)4.6 +/- 0.46 years(1970- 1979)

Age at first pregnancy: age at firstovulation + 1 year

Pregnancy rate: 85-94% of maturefemales

Finite rate of increase (er): r = 7% of totalpopulation per year

Current harvest: No valid information is presenton the current harvest of harp seals in the CanadianArctic (Department of Fisheries and Oceans 1992).The mean known harvest of harp seals on thewhelping grounds off Newfoundland between 1974and 1983 was 176 800 +/- 5 933 (N = 9 years) sealsper year. Since the European ban on the importationof white-coated harp seal pelts, the harvest insouthern Canada averages 55 298 +/- 6 574 (N = 9years) seals annually.

Other impacts: Interspecies competition withringed seals and other marine mammals has beenraised as an issue. Investigations of harp and ringedseal competition suggests that, even with suchcompetition, these seal populations should reach astable equilibrium. Growth rates and carryingcapacities of both populations should be lower withcompetition than in the absence of competition(Innes, pers. comm.), but these changes would notlikely be detectable. Present ringed seal density isprobably below carrying capacity because this speciesis preyed upon by both polar bears and humans.

Thus, the impact of an increasing harp sealpopulation on ringed seal resources should beminimal.

Major issues

Hunting and culture: Harp seals represented animportant source of cash income for Inuithunters until the late 1970s. However, since theEuropean ban on harp seal pelts, there has been noexport market. Harp seals are still an importantsource of food for local dogs. For example, a failureof harp seals to come into Frobisher Bay in 1991forced many local hunters and recreational dogmushers to cut the size of their teams (Pike, pers.comm.)

Seal-fisheries interactions: Direct interference byharp seals in fisheries appears to be rare, tending tooccur only when fish populations are low. Harp sealswere caught in fishing gear in Norway when theBarents Sea capelin stock crashed. Competitionbetween harp seals and fisherman for northern codhas been suggested, but diet studies, carried outprimarily in inshore waters, have not supported thishypothesis. Northern cod have not been shown to bea major component of the diet for harp seals.

Assessment

Stock prognosis: Aerial surveys, hunterobservations and changes in age structure (Roff andBowen 1986) suggest that the harp seal population isincreasing in size.

Management recommendations

1. Harvest levels are unknown, so better harvestdata are needed both from Canada andGreenland. Current harvest seems to be belowoptimum sustainable yield.

2. The use of anti-fertility drugs on this stock tocontrol population growth has been suggested,however, the Baffin Regional Hunters andTrappers Committee opposes this proposal -Population control measures proposed insouthern Canada should be discussed withrelevant Arctic and sub-Arctic communities.

Research requirements

1. To test the relationship between population sizeand morphometric and reproductive parameters,data comparable to those collected in 1950-1980should be collected again.

11

Next AFSAC review

The next review should be carried out when newinformation, as indicated in the researchrequirements, becomes available.

SOUTHEAST BAFFIN BELUGA

Introduction

This stock was last reviewed by the MarineMammals Subcommittee of AFSAC in February1992.

Cliff counts done in 1992 have provided newdata on the size and status of this stock. The MarineMammals Subcommittee, therefore, updated the S.E.Baffin beluga stock sheet in light of these new data.

An aerial photographic survey done in 1990 andcliff counts done in 1991 have provided new data onthe size and status of this stock. The MarineMammals Subcommittee, therefore, reviewed the S.E.Baffin beluga stock in light of these new data.

Background

Stock definition: This stock concentrates inCumberland Sound from late July to October andincludes animals which summer in Frobisher Bay.There is also evidence from catch records that someof these whales summer near Lake Harbour (Richard1990).

Stock size: Based on the 1985 and 1986 surveys,this stock was estimated to number about 500 belugain 1986. An aerial survey, done by DFO in 1990,counted 477 belugas in Clearwater Fiord and alongthe south coast of Cumberland Sound.

Vital parameters: Reproductive andmorphometric data, first reported by Brodie (1971)and Sergeant and Brodie (1969), were collected frombelugas netted in Cumberland Sound. Netting selectsfor females and calves but is not size selective.Stewart (unpubl. data) has collected the most recentinformation from hunter-killed belugas atPangnirtung. Hunters select for large animals, sosampling is biased for large males.

Age at first ovulation: Ovulation begins at amean age of 5 years, assuming that two tooth layersare deposited each year (Brodie 1971).

Age at female at birth of first calf: 6 years(Brodie 1971).

Fatness: Both girth and blubber thickness

have been measured by Stewart (unpubl. data).Summary statistics presented here are based on thesedata. The mean axillary girth/body length of males(N=26) ranged from 0.50 to 0.64, averaging 0.58 +/-0.01. That of females (N=7) ranged from 0.48 to0.72, averaging 0.56 +/- 0.04.

Axillary blubber thickness of males (N=24)ranged from 45 to 8.5 cm, averaging 6.13 +/-0.21 cm and that of females (N=5) ranged from 4.9 to6.9 cm, averaging 5.62 +/- 0.41 cm.

Mean body length: Brodie (1971) summarizesdata for whales older than 10 years: males - 427 cm(N=6), females - 362 cm (N=7). Stewart (unpubl.data) also has data on belugas older than 10 years:males - 429 cm (N=5), females - 393 cm (N=2).Males 6 years of age (N=17) averaged 392 +/- 9.54cm; females 5 years of age (N=5) averaged 364 +/-17.72 cm.

Modal body length: Males (N=26) - 330 cm(Stewart, unpubl. data), females (N=66) - 350 cm(Sergeant and Brodie 1969). In both of these studies,the other gender was under-represented and data wereinsufficient to determine a modal body length.

Largest body length: Males - 445 cm (Brodie1967; Stewart unpubl. data), females - 405 cm(Brodie 1967), 395 cm (Stewart unpubl. data). Apreferred measure is asymptotic body length,estimated to be 455 +/- 1810 cm for males and 399+/- 13.82 cm for females (Stewart, unpubl. data),determined by applying the Von Bertalanffy growthequation to length-at-age data.

Finite rate of increase (er: r = 2.5 % of totalpopulation (Beland et al. 1988; Reilly and Barlow1986). This estimate may be optimistic for this stock -The oldest animal recorded by Stewart (unpubl - data)was 17 years. suggesting a truncated age distributionand abbreviated reproductive period (about 12 years).Modelled population parameters may be optimistic.

Current harvest:. Harvests in 1990/91 were 36 forPangnirtung, 2 for Iqaluit and 21 for Lake Harbour.Assuming a rate of removal of 1.09 to 1.43 timeslanded catch (Cosens et al. 1990), total removal in1991 was 64 to 84 animals. This is 13.4 to 17.6 % ofthe stock, if current aerial survey counts accuratelyestimate stock size.

Other impacts: There is potential for increasedcommercial shrimp fishing in eastern Hudson Strait,the presumed wintering area for this beluga stock(Richard 1990). Nothing is known about the winterecology of either the beluga or the shrimp but it islikely that these whales feed on the shrimp, as dobeluga along the Keewatin coast of Hudson Bay. Anexpanded commercial shrimp fishery could reducethe rate

12

and degree of stock recovery and even furtherendanger the stock at its current low level.

Major issues

There has been disagreement between DFO andthe communities about the best approach tomanagement of this stock. The Southeast BaffinBeluga (SEBB) Committee was struck in 1991 tomake management and research recommendations forthis stock. Dialogue between DFO and thecommunities has also been mediated by the SEBBCommittee -

Assessment

Stock prognosis: The average ‘greatest number ofwhales seen’ and the mean daily counts made in 1992were significantly lower than counts made in 1983.Regression and ‘bootstrap’ analysis indicate the stockis declining. Regression analysis estimates a declinein sightings of 3.3% per year. Bootstrap analysis alsosuggests that the stock is declining, with 77% of thesamples having negative slopes. Although the stockmay be larger than 500 animals and may be decliningmore slowly than was suspected (Cosens et al. 1990),it nevertheless seems to be declining.


1. Management goals for this stock and strategiesfor reaching them need to be defined. It isrecommended that the S.E. Baffin BelugaCommittee develop a management plan for thisstock by April, 1993.

2. The ability of this stock to sustain any level ofharvest continues to be uncertain. Stock sizeshould not be allowed to fall below the currentlevel, as indexed by a population estimate basedon sightings of visible animals.

Research recommendations

1. Stock relationships and, consequently, thegeographic range of this stock are still unknown.Morphometric data, including gender and age,continue to be collected from any whales landedin Lake Harbour, Pangnirtung and Iqaluit. Datashould also be collected from all whales landed atSouthampton Island (e.g. Coral Harbour),Repulse Bay, Cape Dorset, and northern Quebec.Date of capture and reproductive status must alsobe recorded. Additional tools; such as satellitetelemetry, DNA analysis and comparison ofvocal signals, should be considered to addressquestions about stock identification.

2. Growth curves and age-at-harvest data areimportant methods for discriminating amongstocks and assessing stock status. Ageingmethods must be accurate. Ageing techniquesneed to be investigated to corroborate data ondental growth layers.

3. Cliff counts and aerial surveys of whales inClearwater Fiord should be continued, usingidentical methods, so that trends in stock size canbe identified.

Next AFSAC review

The next review should be done after completionof cliff counts or aerial survey counts or whenadditional data, which may clarify stock relationships,become available.

SUB-ARCTIC WALRUS

Introduction

This stock was first reviewed by AFSAC in1986/87 and at that time a recommendation was madethat there should be a re-evaluation after completionof surveys to estimate stock size (Clarke et al. 1989).Aerial surveys have been completed and someresearch projects on this stock are currently inprogress. The results of new information obtained todate are included in this report.

Background

Stock definition: The sub-Arctic walrus stockencompasses those walrus residing in Hudson Bay,Foxe Basin, Hudson Strait and Davis Strait. Atpresent, there are insufficient data to test thehypothesis that walrus in this area can be subdividedinto discrete stocks. Walrus are present in FoxeChannel later in summer than at Coats Island, andinfluxes of walrus into Foxe Channel occur,indicating that there may be movements of walrusfrom Coats Island to Foxe Channel late in thesummer.

Stock size: Visual surveys using systematic striptransects, flown in Foxe Basin, resulted in estimatesof surface animals to number 5 200 (95% C.I. = 900 -30 500) in 1988, and 5 500 walrus (95% C.I. = 2 700- 11 200) in 1989. These numbers have not beencorrected for submerged animals or those surfaceanimals missed by observers. Walrus distribution washighly clumped so estimated surface numbers canhave large variances. Estimates of stock size givenhere are

13

considered to represent an index, not an absolutemeasure of abundance.

In northern Hudson Bay. walrus are most oftenfound in close aggregates in Evans Strait and attraditional land-based haul-out sites on Coats Island.Haul-out sites are also found on pack ice along theBell Peninsula. Following a survey design used byMansfield and St. Aubin (1991), Richard (unpubl.data) made maximum daily counts of 1 376 walrus atCoats Island and a day later 461 walrus atNottingham Island. These numbers only provide anindex and cannot be used as an estimate of stock size.

Vital parameters: Life history data werepublished by Mansfield (1958). However, no recentinformation has been published. Walrus research isongoing at DFO (Stewart. pers. comm.).

Current harvest: Annual landed harvest in1988/89 was 336 walrus and 339 in 1990/91. Themean annual landed harvest reported from 1972 to1985 was 553 walrus (Richard and Campbell 1988).however, the reporting accuracy of harvest data isquestionable (Strong, pers. comm.). Hunting lossesare estimated to be 20 to 32 % or 1.25 to 1.47 xlanded harvest (see Bodaly et al. 1992, for method ofcalculation). Based on the most recently availableharvest data (1990/91 = 339), an estimated totalannual removal of walrus would be 423 - 498 animals(1.25 x 339 to 1.47 x 339).

Other impacts: No serious impacts are identifiedbut potential threats include chemical and acousticpollution and human encroachment on traditionalhaul-out sites. Competition for food may become aproblem if development of commercial fisheriesproceeds. Intersettlement trade in igunuk has begunand Hall Beach has requested that the community beallowed to sell it. This could lead to larger harvests.

Major issues

The information available on catch and stock sizeis poor, making responsible managementrecommendations difficult.

Assessment

Stock prognosis: A cursory analysis of surveydata from 1976, 1977, 1989, and 1990 suggests onlya small probability that numbers of walrus in northernHudson Bay are declining. Additional data would benecessary to verify the trend in stock size. Stockprognosis in Foxe Basin is not possible due to lack ofdata.


1. There are insufficient data to calculate a TAR forsub-Arctic walrus. Given the limited state ofknowledge about this stock or stocks, it isrecommended that harvest rates not be increasedat the present time.

2. Better harvest statistics that include age andgender of harvested animals should be collected.Additional data on morphometrics, physicalcondition and reproductive condition ofharvested animals would also be useful forassessing stock status.


1. Stock identification is needed to determinewhether one or more stocks of sub-Arctic walrusexist. Skin and other tissue samples can be usedfor genetic analysis. Other stock identificationtools should also be used, whenever possible.

2. Data on walrus behaviour patterns should becollected. These data would be beneficial in theinterpretation of aerial survey results.

3. A survey method designed to index walrusnumbers in northern Hudson Bay should bedeveloped. Walrus distribution is clumped whichresults in imprecise estimates of population size.

4. The ongoing study of walrus morphometrics andreproductive rates should be completed. Thesedata will provide much needed information onstock status.

Next AFSAC review

The next review should be done after analysis ofthe morphometric and reproductive data has beencompleted.

MARINE MAMMAL RESEARCH PLAN FORCENTRAL AND ARCTIC REGION

Introduction

The Marine Mammals Subcommittee reviewedthis research plan, which was prepared by R. Stewartin 1991. The following summarizes that plan,incorporating points raised by members of theSubcommittee during discussion.

14

A new paradigm is required to allow DFO tomanage Arctic stocks of marine mammals on datawhich can be realistically obtained. Currentmanagement using replacement yield could continueas experimental management if it has clearly definedhypotheses and objectives, and as one aspect of abroader research program. To support thedevelopment of a more modern and adaptivemanagement approach, the plan proposes a programwhich defines populations and obtains indices ofpopulation abundance for comparison in theframework of dynamic response analysis (trends inrelative abundance), while developing quantitativedefinitions for various life history parameters to beused as optimal sustainable population measures(Table 3). This approach satisfies the needs of sciencein DFO by addressing immediate managementconcerns while advancing marine mammal (fishery)Science by quantifying the processes which governanimal abundance and by developing and testing newmanagement tools.

Research Recommendations

The approach requires much of the same data asare currently being collected. Stock identity andharvest levels are essential. For each stock, variousbiological, population and habitat parameters wouldbe assessed relative to other harvest levels. Thisapproach permits the monitoring of trends in amultivariate perspective which is more sensitive andpredictive than comparing estimates of absolutepopulation size. The technique has been usedsuccessfully for polar bears, in part due to theextensive network of biologists to sample bears.

To implement this modern approach, researchersin the Region should form a more cohesive unit andmore stable budgets. By adopting this plan, Sciencein Central and Arctic Region can ensure data arecollected in a cost-effective manner using the mostmodern or appropriate techniques. The approach isamenable to addressing immediate concerns, whiledeveloping a deeper understanding of the biologicalprocesses. To do this, specific requests from clients(resource managers, supervisors, resource users,settlement area representatives) must identifyinformation needs rather than request specificprojects. Without these changes, current data will beanalysed in the context of dynamic response analysisover the next 5 years, but there will be littleadvancement in DFO’s management of Canada’sArctic marine mammals or fishery (marine mammal)science.

REPORT OF THE AFSAC FISHSUBCOMMITTEE: 1991/92

INTRODUCTION

On March 9-10, 1992, the AFSAC FishSubcommittee met to review the 1992/93 quotarecommendations for the Northwest Territories’commercial fisheries for anadromous Arctic charr, toevaluate the status of three anadromous Arctic charrfisheries, and to begin a comprehensive evaluation ofthe Great Slave Lake commercial lake whitefishfishery.

Membership on the Fish Subcommittee consistedof:

R. Crawford (Science, Central and ArcticRegion) Chairperson,September 1991- June1992)

A. Kristofferson (F&HM, Central and ArcticRegion)



At that meeting, the Fish Subcommittee reviewedthe following documents:

AFSAC Background Report: “The Great SlaveLake Commercial Lake Whitefish, Coregonusclupeaformis, fishery” by A.C. Day and G. Low.AFSAC Document 91/92-08.

AFSAC Stock Status Report: “Arctic Charr ofthe Sylvia Grinnell River” by D. Pike. AFSACDocument 91/92-02.

AFSAC Stock Status Report: “Stock Status ofArctic Charr. Ikaluit River, Baffin Island.Northwest Territories” by M. Roberge and C.Read. AFSAC Document 91/92-03.

AFSAC Stock Status Report: “Stock Status ofArctic Charr in the Diana River, NorthwestTerritories” by A.H. Kristofferson, D.K.McGowan, and G.W. Carder, and R.F. Tallman.AFSAC Document 91/92-06.

AFSAC Quota Summary: “QuotaRecommendations for Commercial Fisheries ofAnadromous Arctic Charr. Northwest Territories,1992/93” by A.H. Kristofferson, G. Low, and D.Pike . AFSAC Document 91/92-05

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GENERAL COMMENTS

The Subcommittee thanks all those involved inthe preparation of the background reports for theiruntiring efforts. It recommends, and urges strongly,that these documents be prepared for publication inthe Canadian Fisheries and Aquatic SciencesTechnical Report series, or other suitablepublications, if and when appropriate.

The following sections summarize the review ofthe background documents, and provide a statementof the conclusions and recommendations of the FishSubcommittee. Note that references to ‘charr’ in thefollowing reports mean Arctic charr unless otherwisespecified.

LAKE WHITEFISH - GREAT SLAVE LAKE

Introduction

The background report provided a history of thelake whitefish fishery on Great Slave Lake. Thecomplex history of fishery management practices thathave occurred on Great Slave Lake since its inceptionin 1945 were reviewed. The Fish Subcommittee notedthat this report is a valuable aid to the study of thepresent condition of this fishery and recommendedthat the author publish it in the Manuscript Reportseries of Fisheries and Aquatic Sciences.

Author’s Abstract

The lake whitefish, Coregonus clupeaformis, isthe target species of the commercial fishery of GreatSlave Lake, Northwest Territories. In the past, laketrout (Salvelinus namaycush). was also a targetspecies of the commercial fishery but by the late1960s lake trout stocks in the western part of the lakehad collapsed due to overexploitation. The fisherybegan in the summer of 1945. Annual production ofall species peaked in 1949 at 4 055 t, declinedsteadily to approximately 1 250 t by the early 1970s,and remained at this level until the mid 1980s.Between then and the present, annual productionincreased to approximately 2 000 t. During the fiscalyears of 1988-89 and 1989-90, the lake whitefishharvest from Great Slave Lake constitutedapproximately three quarters of the commerciallandings and one half of the landed value of allcommercially caught fish in the NorthwestTerritories.

The history of the lake and management of itsfishery are unique with respect to other Canadiancommercial fisheries because, from the onset of thefishery to the present, (1) commercial fishing has

been done with 5 1/4 and 5 ½ inch gill nets only, (2)the production and biological parameters of thecommercially caught species have been monitored onan annual basis, (3) there have been no successfulintroductions of non-native species to the lake, and(4) the lake has remained relatively unpolluted.Harvests of the fishery are controlled by quotas whichare assigned to each of 7 management areas of thelake. The fishery and the reporting of its harveststatistics are divided into a summer season (May 16to Oct 31 of a given calendar year) and a winterseason (Nov 1 to May 15 of the following year). Inthe past, aggregate quotas (catch of all species) wereassigned by management area, fishing season, andfishing year, but presently they are assigned bymanagement area and fishing year only. Area 6 in thenortheast arm of the lake supports a lake trout sportsfishery and was commercially fished in the past, butis presently closed to commercial fishing. The historyof the management areas and their respective quotas,closures, and locations is dynamic and is the result ofa complex interplay between economics, politics, andfishery management advice. The fishery has beensubsidized since the formation of the Freshwater FishMarketing Corporation in 1969, and is considered tobe economically marginal.

Biological assessments of the lake whitefish andother commercial fish stocks (walleye, northern pike,lake trout, inconnu) have been conducted on anannual basis since 1945. In 1971 the Department ofFisheries and Oceans initiated a three part fieldprogram composed of fish sampling in the four fishplants on the lake, fishery observations andexperimental netting. The four objectives of thisprogram are (1) to maintain records of commerciallandings of all species, (2) to maintain records ofcatch per unit effort, cullage, and relative abundanceof all species, (3) to assess and record changes in thepopulation parameters of lake whitefish, and (4) toassess the population structure of all fish species.

Management Recommendations - none


1. It is recommended that a synoptic analysis beperformed on the data accumulated since 1971,and that the effectiveness and validity of thecurrent monitoring programs, quotas andmanagement areas be re-evaluated by examiningthe results of the aforementioned analysis in lightof (1) the results of a stock structure study whichis at present not completed, (2) an estimate ofyield for whitefish on a per stock and permanagement area basis, and (3) trends in thepopulation structure of whitefish.

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2. It is also recommended that a review beconducted on the effects of scale-derived ages onpopulation parameter estimates of Great SlaveLake lake whitefish.

Next AFSAC Review

February 1993.

ARCTIC CHARR - SYLVIA GRINNELL RIVER

Introduction

The Sylvia Grinnell River is located near Iqaluiton Baffin Island. The fishery for Arctic charr on thisriver was once one of the most productive in theeastern Arctic, producing over 5 000 kg per year overthe period 1958-1966. The commercial fisherycollapsed in 1967 and has not recovered. Fishing forrecreational and subsistence purposes has continued.Available evidence indicates that the stock continuesto be in a depleted state.

Background

Stock definition: Unknown; suspected to beunique but small charr populations occur in fourrivers within 20 km of each other.

Stock size: Unknown. An assessment has beendone. Extrapolation from harvest statistics results inan estimated run of about 160 000.

Vital parameters: Age and size distributions weretruncated in 1991, relative to 1948-50 data. Mean sizein 1991 was down to 343 mm from 474 mm in earlydata; mean age was down to 8.1 years from 13.7years. Length-at-age curves indicated fish in 1991were growing slowly relative to those in 1950.

Current harvest: Annual domestic catch hasvaried between 2 000 kg (1986) and 3 600 kg (1991).Fishermen are targeting smaller fish because theynow use 88 mm mesh nets. Sports catch in 1991approximated 400 kg. No commercial fisherypresently exists.

Other impacts: A possible pollution threat existsfrom Iqaluit town dump sites. Increased sport harvestis anticipated and hydroelectric development on theSylvia Grinnell has been proposed.

Major Issues

Stock depletion: In spite of the closure of thecommercial fishery since 1967, there is no sign of

recovery by the Arctic charr population.

Harvest levels: Current domestic and sportfishing levels are too high to allow stock recovery andfishing pressure will likely increase.

Possible pollution from town dump: This isviewed by Iqaluit townspeople as the major cause forfish population decline in the Sylvia Grinnell River.

Assessment

Stock prognosis: The Sylvia Grinnell RiverArctic charr population has been overexploited in thepast, and there is no sign of recovery, in spite of yearsof management efforts toward that end. Regulatoryamendments to reduce the sports fishery catch limitare to be implemented in 1992. Proposedamendments to regulate the domestic fishery (e.g.increase minimum mesh size. area and seasonalclosures, etc.) require consultation with the usergroups. There is significant disagreement betweenuser groups and DFO as to the root cause of the lownumbers of fish. However, this issue remainsunresolved.


1. There should be attempts to improvecommunications between DFO and the resourceuser groups. Information packages on the“Biology and Stock Status of Sylvia GrinnellRiver Arctic Charr” and “Why large mesh netsare recommended for the Sylvia Grinnell Riverfishery”, should be prepared by DFO staff.

2. There should be increased opportunities forpublic input to the management plan for thisriver.

3. The net exchange program should be continuedand more actively promoted.


1. The possible threat of the Iqaluit communitydump sites to the heath of the Sylvia GrinnellRiver Arctic charr population should beexamined.

2. The possibility that faster growing fish may havebeen extirpated from the population by years ofoverfishing should also be studied.

3. The feasibility of installing a fish ladder at thetidal falls to circumvent the obstruction andreduce the vulnerability of fish waiting at theriver mouth for upstream mi-

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gration should be examined.

4. A fish hatchery has been proposed for the river inthe past, but this is not now recommended as asolution.

ARCTIC CHARR - IKALUIT RIVER

Introduction

The Ikaluit River is located on Tay Sound, BaffinIsland, near the community of Pond Inlet. The riversupports subsistence, commercial, and sport fisheriesfor Arctic charr. Most commercial and subsistencefishing is carried out in Ikaluit Lake, whereas mostsport fishing occurs in Ikaluit River. Concerns havebeen expressed by Pond Inlet residents about declinesin the size and numbers of Arctic charr in the IkaluitRiver run, leading to recent assessments by DFO onthis stock.

Background

Stock definition: With limited informationavailable, the charr found in this river are assumed tobe a single stock.

Stock size: The upstream migration of charr wascounted for the first time in 1989. Between 6-27August, 282 576 fish were counted.

Vital parameters: Fish length in the samplestaken from the 1989 run had a bimodal distribution:smaller fish were between 280-299 mm; larger fishwere between 400-419 mm. Fish larger than about460 mm were mature (age 12+); sex ratio was 1:0.7(males:females). The mean condition factor (K) forboth sexes was 1.23. Instantaneous total mortality (Z)of adult charr was0.59.

Current harvest: The commercial harvests in1988 and 1989 were 2 246 and 2 300 kg,respectively. The corresponding subsistence harvestwas estimated to be about 6 800 - 9 000 kg. Theannual sport fishing harvest since the late 1970s wasestimated to be about 100 kg. Total 1989 harvest wasthus estimated at about 11 000 kg.

Other impacts: None identified.

Major Issues

Subsistence harvest: There are no accurateestimates of the subsistence harvest. For example, in1987 estimates by DFO and Renewable Resourcesvaried between 1 800 - 40 000 kg.

Exploitation rate: Although definitive data arelacking, there is evidence that total exploitation rateby the commercial, subsistence and sport fisheriesexceeds 0.045.

Assessment

Stock prognosis: There is evidence that fishingmortality has reduced the number of large. fecundfish from the stock. Clarification of the studymethodology is required before conclusions on thisstock can be made.


1. A provisional commercial harvest of 2 300 kg isrecommended, which is the status quo.

2. Commercial catch data from the 1989, 1990, and1991 fisheries, if available, should beincorporated into an emergency stock statusreport to be prepared for the February 1993AFSAC meeting.


1. The study of the subsistence fisheries harvest sizeshould be given urgent priority.

2. It is recommended that a carefully designed falltagging study be carried out to estimatepopulation size (spawners and non-spawners) inthe upstream and estimate subsistence harvest (bytag ratios from the commercial and subsistencefisheries).

Next AFSAC Review

February, 1993.

ARCTIC CHARR - DIANA RIVER

Introduction

The Diana River is tributary to Hudson Bay nearthe community of Rankin Inlet. Inuit havetraditionally utilized the charr of this river forsubsistence purposes - Sport fishing began in the late1950s and commercial fishing in the Rankin Inletarea began in the 1960s. The commercial fishery ofthe area was closed in 1985, and the subsistence catchvoluntarily reduced, due to evidence of decreasingcatches, and size and age of fish caught. Assessmentof the stock has been carried out to evaluate anypossible stock recovery.

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Background

Stock definition: Because of the largefluctuations in the number of upstream migrants inprevious years, it is likely that the run includes asignificant number of individuals which overwinteredin another system the previous year. Thus, theupstream counts on the Diana River may not providea reliable estimate of this stock or stocks.

Stock size: The upstream migration of charr wascounted in 1991. About 29 000 fish were counted, ascompared to 40 000 - 86 000 fish annually over theperiod 1973 - 1986.

Vital parameters: Fish taken from the 1991commercial fishery had a modal length of 550-600mm. a modal age of 10+ years, mean fork length of598 mm, and 48% were 600 mm or larger in length.Fish caught in the 1991 upstream run had a modallength of 350-400 mm. modal age of 9+ years, meanfork length of 419 mm, and only 8% were 600 mm orlarger in length.

Current harvest: The 1991 commercial harvestwas 5 550 kg and the subsistence harvest wasestimated to be 5 100 kg. The sport fishing harvestwas estimated to be 370 kg. Total harvest was thusestimated at about 11 000 kg.

Other impacts: There is a possibility thatcumulative effects of major hydro-electricdevelopments on rivers entering Hudson and JamesBays could be impacting charr stocks along theHudson Bay coast.

Major Issues

Stock identification: Stock identification isconsidered to be a pressing issue for the managementof this fishery. Understanding the apparentintermixing of stocks at some overwintering sites andduring mid-summer when commercial fisheriesoperate is needed.

Subsistence harvest: Because direct sampling hasnot been done, subsistence harvest has been estimatedfrom previous, community-based research. Thus, therelationship of this harvest to particular charr stocksis uncertain.

Assessment

Stock prognosis: The Diana River stock has beenoverexploited in the past, as indicated by decliningcommercial harvests and mean sizes for the stockmeasurements in the early 1980s. Biological samplingof the 1991 commercial harvest suggests that some

increase in mean size has occurred since the closureof the fishery in 1985. However, size and abundanceof charr has not recovered to levels seen in the early1980s. Cohort analysis indicates that fishing pressuredue to the subsistence harvest may have been quitehigh since the closure of the fishery and this mayhave impeded stock recovery.

Variability of weir count data suggests thatstraying among adjacent streams may be significant.Whatever the cause, this variability complicatesinterpretation of the size of the population fromupstream counts. For example. the relatively smallsize of the upstream run in 1991 suggests a furtherdecline in population numbers since the mid-1980s.However, average size and age data suggest a partialrecovery. Without further study, the true dynamics ofthis stock are not predictable.


1. The commercial fishery quota should not exceed4 000 kg. The Fish Subcommittee recognizes theinvolvement of the local community in resourcerecovery efforts. Continued commercial fishing isrecommended to provide a tag recoverymechanism for a proposed downstream taggingprogram to estimate subsistence harvest. Thecommercial harvest will also provide anopportunity for collection of a good biologicalsample for continued fish population assessment.


1. It is recommended that cohort analyses, and othermodern statistical tools be utilized in additionalstudies of the performance of this and otherArctic charr fisheries.

2. The study of subsistence fisheries to quantifyharvest levels should be given urgent priority. Aspring downstream tagging study should be donein the Diana River to derive an estimate of thesubsistence harvest of this fishery.

QUOTA RECOMMENDATIONS FOR:COMMERCIAL FISHERIES OF ANADROMOUS

ARCTIC CHARR,NORTHWEST TERRITORIES - 1992/93

Summary

With the exception of the rivers noted below, the1992 quotas outlined in Table 1 are endorsed.

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Ekalluk R.

The commercial fishery was closed by agreementwith the local community which is activelyparticipating in resource recovery efforts. The fisheryshould remain closed. If the fishery is opened, thequota should not exceed 7 500 kg. It is imperativethat DFO obtains a sample in 1992 for biological dataanalysis. Samples obtained during the first few daysof the run should be avoided.

Kulguyak R.

Fishermen licensed to participate in this fisheryhave been setting their nets several kilometres awayfrom the river, and may have been exploiting a mixedstock of fish in a summer feeding ground. Thecommercial licence should be modified to contain arestriction which limits fishing activity to the rivermouth proper. It is also recommended that a taggingstudy be conducted in the Ellice River in 1992. Tagrecoveries must be monitored in both the Ellice andKulguyak fisheries for evidence of migratoryexchange of fish and overlapping exploitation.

A properly managed partial weir should beconsidered as the primary capture method for remotesites such as Kulguyak to minimize weather-causedcullage episodes.

REPORT OF THE ARCTIC FISHERIESSCIENTIFIC ADVISORY FISH SUBCOMMITTEE

FOR 1992/93

INTRODUCTION

The 1992/93 meeting of the AFSAC FishSubcommittee was held on February 2 and 3, 1993.Membership of the Fish Subcommittee consisted ofthe following:

B.G.E. de March (Science, Central and ArcticRegion). Chairperson


E. Gyselman (Science, Central and ArcticRegion)


G. Low (F&HM, Yellowknife, Centraland Arctic Region)

J. Lambert (Science, Quebec Region)

J. Lambert did not attend the meeting butreviewed the reports and provided committeemembers with written comments. He also receiveddraft reports resulting from this meeting andcommented on their content. His comments havebeen incorporated into this reports:

At that meeting, the Subcommittee consideredthe following reports:

- Stock Status of Arctic Charr in the KuujjuaRiver, Northwest Territories. LA. Harwood.(AFSAC Document 1992/93-04)

- Stock Status of Arctic Charr in Freshwater Creek,Northwest Territories. A.H. Kristofferson, D.K.McGowan, GW. Carder, and G. Low. (AFSACDocument 1992/93-05).

- Quota Recommendations for CommercialFisheries of Anadromous Arctic Charr,Northwest Territories 1993/94. A.H.Kristofferson, G. Low, and D. Pike. (AFSACDocument 1992/93-06).

- The Great Slave Lake Commercial Inconnu.Stenodus leucichthys, Fishery. AC. Day and G.Low. (AFSAC Document 1992/93-07).

The following reports were deferred either one ortwo years, and the stocks were not reviewed -

- Stock Status of Broad Whitefish, LowerMacKenzie Basin. R. Tallman.

- Revision of 1991/92 Stock Status Report ofArctic Charr in the Ikaluit River, NorthwestTerritories. C. Day.

- Stock Status Report of Arctic Charr in theHornaday River, Northwest Territories. L.Harwood.

The Subcommittee’s mandate was to examine thesubmitted reports vn the stocks under review, reporton the current status of stocks under examination,recommend management strategies based on presentdata and recommend on aspects of research needed toimprove the management of the stocks -

The Subcommittee thanks all those involved inthe preparation of background reports. It recommendsthat these documents be prepared for publication inthe Canadian Fisheries and Aquatic SciencesTechnical Report Series or other distributed media.

The following sections summarize the reviews ofthe background documents, and provide the con-clusions and recommendations of the Fish Subcom-

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mittee.

Note that references to ‘charr’ in the followingreports mean Arctic charr unless otherwise sped fled.

ARCTIC CHARR - KUUJJUA RIVER

Introduction

The Kuujjua River, which flows into Minto Inlet60 km northeast of Holman, NWT, has been thetraditional source of many of the charr taken in thesubsistence fishery of that community. In addition, acommercial quota of 600 kg was established in 1979to supply the local market, however, recent fisheriesdevelopment efforts have been directed to the eastend of Prince Albert Sound.

In 1991, the Fisheries Joint ManagementCommittee (FJMC) initiated a community-basedharvest monitoring program in response tocommunity concerns about the Kuujjua charr stock.The harvest data and biological sampling programwas expanded in by FJMC in 1992, to include a stockassessment program which included enumeration ofthe 1992 returning migrants to the Kuujjua Riversystem -

Background

Stock Definition: Anadromous Arctic charr thatspawn and overwinter in the Kuujjua River systemare assumed to comprise a discrete stock. Tag andrecapture information appear to support thishypothesis. Genetic analysis of samples collected in1991 and 1992 are in progress. There is tag andrecapture evidence that during the summer feedingmigration, the Kuujjua stock mixes with four PrinceAlbert Sound charr stocks in coastal areas that arefished by Holman residents.

Stock Size: A total of 10 493 charr were countedthrough a full-span conduit weir between August 11and September 8, 1992. The operation of the weiradequately spanned the timing of the upstream charrrun (August 23 to 31). Therefore, it appears the entirerun was counted.

Vital Parameters: Based on 2 358 length samplesfrom the weir study, mean length was 453 mm (range280 - 787 mm) with a single mode at 400 mm. Meanage was 10.2 years (range 7 - 19) with the mode at 10years based on a sample of 95 charr. Instantaneoustotal mortality (Z) calculated for the ages 10 to 15years was 0.346 (29%/year). The mean conditionfactor was 1.21.

Charr taken with 127 mm and 139 mm gillnets

during the 1992 winter fishery at Tatik Lake, on theKuujjua River system, were somewhat larger andolder than the weir sample, probably due to gearselectivity. Size and age (mean length 531 mm andmean age 11.1 years) for charr sampled from the1992 Tatik Lake fishery declined from 636 mm and12.8 years in 1987. By comparison, Kuujjua charrwere considerably smaller and younger than charrtaken with 127 mm gillnets in 1992 at TahiryuakLake on the Kuuk River system (mean length 788mm, mean age 15.9 years).

Current Harvest: Kuujjua charr is harvested in amixed stock summer fishery at Safety Channel and inother coastal areas near the community. Although therelative contribution of the various stocks to thesummer fishery is largely unknown, a highpercentage (206Z) of net marked fish returning to theKuujjua River confirms that the stock is heavilyexploited in the summer fishery.

The fact that fifty-five percent of charr tagged atKuujjua River in 1969 were recovered in the summerHolman fishery provides further evidence of summerexploitation of this stock. Based on the aboveinformation, the best estimate of mean summerharvest is 1 700 Kuujjua charr, (Approximately 50%of the mean (1989 - 1992) annual harvest of 3 341charr).

Kuujjua charr are also harvested in a fall under-ice fishery, primarily at Tatik Lake. Mean annualharvest (1989 - 1992) is 2 600 charr (range 1 500 -3 300 fish).

The best available estimate of total annualremoval of Kuujjua charr is 4 300 fish, consisting of1 700 during summer and 2 600 during fall.Therefore, the current harvest level based on the 1992weir count of 10 493 charr is 41%.

Other Impacts: No other serious impacts areidentified at this time.

Major Issues

Overharvesting: The stock appears to be in adepressed state due to overharvesting.

Assessment

Stock Prognosis: Given the recent reduction inmean size and age of charr in the Kuujjua system, thehigh proportion of net marked fish (21.6%), the highrecovery of summer tagged fish in the 1992 fallharvest (21%), and observations by the communityusers that fish are smaller and fewer in number, it isclear that the Kuujjua River stock is heavily exploitedand probably in a depleted state. The presentexploitation rate for

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the Kuujjua charr stock is at least double and perhapsas high as four times the maximum harvest of 10%currently recommended as a Safe Harvest Level(SHL) for eastern form Arctic charr stocks. If currentharvest practices continue, the stock will remain in adepressed state and further stock damage is expected.If, on the other hand the community decides onharvest levels that will permit recovery, the stock willlikely begin to recover. Other over-exploited charrstocks in the central Arctic (Ekalluk River andFreshwater Creek stocks) have shown positiveresponses to reduced fishing pressure. Speed ofrecovery appears to be dependent on the reduction infishing pressure on the stock.


1. The following are the recommended harvestlevels for the Kuujjua River charr stock based onlevel of risk and expected recovery.

a) Harvest level = 0% - 0 fish - best recoveryexpected, no further risk from fishing.

b) Harvest level = 3% - 315 fish - slow tomoderate recovery expected, low risk.

c) Harvest level = 5% - 525 fish - slow recoverypossible, some risk.

d) Harvest level = 10% -1 050 fish - norecovery expected, stock at risk.

e) Harvest level = greater than 10% (more than1 050 fish)- continued stock depression, high risk forstock,

2. In consultation with the community, a fishingplan for the Holman area, including the PrinceAlbert Sound and Minto Inlet (Kuujjua River)fisheries, should be initiated. It should beprepared jointly and implemented prior to the1993 summer fishery. The fishing plan shouldinclude harvest levels for both the summer andfall fisheries which exploit the Kuujjua stock, butalso it should include a strategy for the use ofmore remote fisheries to serve the fishery needsin the community during the recovery period ofthe Kuujjua stock.

3. The use of 139 mm (5.5”) mesh size isrecommended for the Holman fisheries. If thecommunity decides to continue fishing in themixed stock areas, the exclusive use of largermesh nets will target larger fish from less heavilyexploited Prince Albert Sound stocks and mayresult in a lower percentage of Kuujjua charrbeing harvested in the summer fishery.

4. There should be no commercial fishing activity inthe Kuujjua River system, or in the mixed fishery

coastal waters, until the stock has recovered and alldomestic fishery needs have been met.

5. Accurate harvest statistics, as well as biologicalsamples of the catch should be collected eachyear in order to develop a yield model of thisstock and monitor the progress of recovery. Tagreturns from the remaining fishing activity shouldbe aggressively pursued.

6. Consideration should be given to repeating theweir project at the Kuujjua River in 1993 or 1994to recover tags and to obtain a second count. Theharvest levels recommended to the communityare based on a single enumeration of thereturning migrants. A second count wouldprovide more information on possible variation inrun size and increase confidence in therecommended harvest levels.

Research Requirements:

1. The Kuujjua River charr stock should be thesubject of a weir enumeration study in 1997 tomeasure its state of recovery.

2. A yield model should be developed to determineTotal Allowable Catch (TAC) once the stock hasrecovered. Future management of the fisherycould then be based on TAC, ensuring a longterm sustainable fishery.

3. The stock identity and discreteness ofanadromous charr in the Kuujjua River system,and elsewhere, should be determined by geneticand morphometric analysis of samples collectedfrom all stocks in the Minto Sound and PrinceAlbert Sound area.

4. Population dynamics studies on Arctic charrshould continue in order to determine optimumyields.

Next AFSAC Review: 1997/98.

ARCTIC CHARR IN FRESHWATER CREEK,NORTHWEST TERRITORIES

Introduction

Freshwater Creek drains Greiner Lake. VictoriaIsland, NWT to the Arctic Ocean at Cambridge Bay.Enumeration of migrating charr in this short streamwas carried out in 1982, 1988 and 1991, and a surveyof subsistence and sport harvests was carried out in1983 and 1992. As a

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result of poor catches in 1987, a moratorium on allgillnetting was imposed in 1988 and is still in effect.As a result of the 1988 enumeration, sport fishinglimits were reduced. The present report discusses themost recent studies and provides recommendationsfor use of this resource.

Background

Stock definition: In the 5 years following the1982 study, 163 of the 808 fish tagged wererecaptured. Most (87%) were recaptured either in thedrainage system or within 20 km of the creek mouth.Thus, although there is some straying, it is believedthat the majority of the fish over-wintering comprise adiscrete stock. Summer distribution appears to bewithin 50-60 km of Cambridge Bay.

Stock size: The upstream migrant counts in 1982,1988, and 1991 were 9 961, 36 933, and 39 559respectively. The dates of the runs in these three yearswere 20 Aug. - 7 Sept., 20 Aug. -19 Sept., and 13Aug. - 12 Sept. respectively. Judging from the shapeof the graph depicting the daily counts, the majorityof the run was enumerated in each of the three years.

Vital parameters: Fork length (mm) and ages (y)of migrating fish calculated from random samples ofcatch. The sample number for large fish was small.

year 1982 1988 1991

Sizemode (mm)

550-599 350-399 400-449

Range (mm) 220-765 199-765 215-865

# fish in

550-599

mm size class 2 860 2 115 3 700

Age

mode (y) 12 8 10

Range (y) 6-18 6-17 4-16

Instantaneous total mortality (Z) calculated forfish of ages 12-15 years was 1.85 (84%) in 1982, 0.30(26%) in 1988, and 0.26 (23%) in 1991.

Current Harvest: In 1983 anglers harvested 637charr and other fisheries harvested around 1 000

fish for a total of 1 600 - 1 750 fish. Estimates ofexploitation rate varied from 12-17.5% depending onwhich population estimate is used.

The 1992 survey of sport and subsistencefisheries was carried out 12-24 July and 23 Aug. - 6Sept., coinciding with the upstream and downstreamruns. A total harvest of 1 315 charr (and 524 laketrout) was reported, of which 193 were taken in thesport fishery. It is estimated that an additional 300-350 charr from this stock were taken at sea near thecommunity of Cambridge Bay, and there is a possiblefurther harvest of 600- 700 Freshwater Creek charr aspart of the “Gravel Pit” fishery. (15 tags wererecaptured here from the 1983 tagging effort). Thusthe total current harvest is probably between 1 600and 2 300 charr.

The ratio (number in catch)/(number in upstreamrun), indicates an exploitation rate of 4-6%. However,because the fishery is size selective this figure is notdirectly comparable to the 1983 estimate of 16-17.5%. In 1982, 94% of the fish in the upstream runwere 400 mm and larger and thus available to thefishery. In 1992, 94% of the angled catch was 400mm or larger but only about 64% (25 400 fish) of thefish in the 1991 upstream run were this size or larger.Thus the exploitation rate, comparable to the onecalculated for 1982, is closer to 6-9%. This is veryclose to the exploitation rate of 11% of fish of thissize which lead to a decline of the Nauyuk Lake stock(Johnson 1989).

Other Impacts: During the upstream run, August1991, large gravel trucks were observed crossing theriver. The owner “ultimately” complied with a DFOrequest to discontinue this activity during the run.

Major Issues

Moratorium on gillnet fishing: In January 1988, itwas agreed at a public meeting to impose a ban on allgillnetting in Greiner Lake, Freshwater Creek, andtributaries and waters of Cambridge Bay. The ban ondomestic fishing was to be voluntary and compliancewas to be handled by The Cambridge Bay Huntersand Trappers Association (HTA). In addition, sportfishing catch was to be reduced from 4 daily and 7 inpossession to 1 daily and 7 in possession. Compliancewould be by enforcement of NWT FisheryRegulations.

The moratorium was to be in effect for 1988,1989 and 1990. The ban which did not apply to the“Gravel Pit” (a mixed stock fishery) was reasonablywell adhered to in the Freshwater Creek area, but lesswell in the other waters surrounding the communityof Cambridge Bay. The

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HTA extended the ban to 1991, to await results of theenumeration, and, subsequently, as a result of thatenumeration has extended the ban for a further 3years.

Assessment

Stock size and structure: It appears that the stockhas recovered from a low of less than 10 000 in 1982to almost 40 000 in 1991. This represents an averageincrease of 24.5%/year between 1982 and 1988, and2.3%/year between 1988 and 1991. The increase innumbers between 1982 and 1988 is largely due to theaddition of smaller, younger fish. Although thenumbers have increased, the modal size is still about150 mm shorter than in 1982.

Stock recruitment: The recruitment between 1982and 1988 is very high. One possible explanation isthe mechanism hypothesized by Johnson (1989), whosuggested that recruitment might not take place untilthe population reaches a critical low level. Sometimebetween 1982 and 1988, that low level was reached,and considerable recruitment occurred. Thismechanism is supported by the observation that alarge number of smaller fish were evident in 1988.However, other explanations such as immigrationcannot be discounted -

Length at age: In 1982 the modal age and size ofthe run was 12 years and 550-600 mm respectively.The modal length group was comprised of fish of 10-13 years of age. About 50% of a smaller peak of 400-450 mm fish were 8 years, but the group age rangedfrom 8-13 years.

In 1988, 70% of this 400-450 mm length groupconsisted of 8 year olds, and by 1991, was lengthgroup was dominated by 9 and 10 year old charr. In1982 the 500-650 mm group comprised 12 and 13year olds, in 1991 it was dominated by 11 year oldfish. Although the data are partly confounded by thesuggestion that the 1982, 8 year old fish were onlypartly recruited to the migrating population (becauseof their relatively small size compared to 1991, 8 yearolds), it is argued that the charr population is stilllarge for its age compared with 1982.

Mortality: Comparison of the 1988 and 1991 dataindicate a considerable reduction in 12 year and olderfish in the run. There were 4 800 9- year-olds in1988, but only 784 survived (as 12 year olds) to 1991.This is an average annual mortality of 46% per year.If all fish 9-13 years old in 1988 are considered, thenaverage annual mortality to 1991 is 44%. If naturalmortality is 17% year (Dempson 1978), 27% per yearcould be due to the fisheries. In 1991, this 27% wouldrepresent 1 300 fish. This roughly agrees with the

harvest figures mentioned earlier (1 600 - 2 300 fish).These figures suggest that fishing may have had asignificant effect on the population between 1988 and1991.

Stock prognosis: A conservative interpretation ofthese data suggests that this stock was overexploitedin 1982, and then increased in numbers migratingupstream by 1988, and subsequently increased inmodal size since 1988. These changes might beattributed to reduced harvests in the years 1983 to1987. The 1992 harvest has approached that of 1982,although since the total population is larger, thispresent day impact is less than that in 1982.Supported by examination of other, nearby stocks,and of the size and age structure of the 1991 results, itis believed that this stock has not yet recovered. Tofacilitate this recovery it is suggested that the harvestshould be limited to 2 300 charr annually, and thatthis limit be imposed until 1994, when the upstreamrun should be reassessed. In the intervening yearsaccurate annual harvesting statistics should becollected to allow development of a yield model andan estimate of the Total Allowable Catch.


1. The moratorium on gillnet fishing in FreshwaterCreek and its headwater lakes should becontinued until 1994.

2. A fishing plan should be developed with thecommunity of Cambridge Bay through the HTAto limit the subsistence fishery so that the totalharvest of charr from Freshwater Creek and itsheadwater lakes does not exceed 2 300 charr/yearup to and including 1994.

3. The status of the Arctic charr stock in FreshwaterCreek should be assessed in 1994, byenumerating the upstream run, using a weir, todetermine the state of recovery of the stock.

4. Accurate harvest statistics, including a randombiological sample of the catch are required everyyear so that a yield model applicable to this stockcan be developed.


1. A yield model should be developed to allowdetermination of a Total Allowable Catch (TAC)and development of a management plan based onthis TAC to ensure long term optimalexploitation of this resource.

2. The stock identity of the anadromous charr in thiscreek should be investigated and com

24

pared to those in adjacent systems by geneticstudies of spawners.

3. The degree of mixing of Arctic charr betweensystems during non-spawning years should bedetermined.

4. Studies of the population dynamics of the easternform of Arctic charr should continue in order todetermine optimal yields.

Next AFSAC Review: 1994/95.

THE GREAT SLAVE LAKE COMMERCIALINCONNU, Stenodus leucichthys, FISHERY

Introduction

Inconnu have been fished commercially on GreatSlave Lake since 1945. In recent years, there has beenan apparent decline in the stock(s) to the point thatjust two of five rivers that previously supported afishery, the Buffalo and the Slave, still supportfisheries. The stock(s) in the other rivers have beenlargely or totally depleted.

Inconnu make up a small proportion of theoverall commercial fishery on Great Slave Lake (lessthan 10%). However, value to the fishermen isdisproportionately high because inconnu is sought forthe smoked product market. The commercialfishermen are anxious to maintain an inconnu harvestbut are aware that the stock(s) are depleted and atemporary closure of the fishery may have to beimplemented if the fishery is to survive.

Background

Stock Definition: It is not known whethermultiple stocks exist in the lake nor whether any riversystem contains more than one stock. Historically,inconnu were reported from many river systemsemptying into western basin, but now only one or twosystems are known to support runs. Some stocks mayhave already been eliminated in the lake.

Stock Size: Based on CPUE figures, the size ofthe Buffalo River stock(s), if it is a distinct stock, hasdeclined by 90% since the mid 1970s. In recent years,there have been several, often consecutive, year classfailures, and this has prevented the stock(s) fromrecovering. This is believed to be due to the persistentharvesting of potential spawners.

Vital Parameters: Growth rates of inconnu inGreat Slave Lake are high compared to other stocks

in more northerly latitudes in Canada. Growth rateshave increased since the commercial fishing began,but the mean length of the fish in the commercialharvest has declined. Similarly, mean age hasdeclined since 1945. Both of these trends areindicative of overexploitation.

Instantaneous mortality rates in the years 1971and 1973-1983 ranged from 0.66 (48%/year) to 1.06(65%/year), up significantly from 0.20 (18%/year)shortly after the fishery began in 1947. The rate for1972 was exceptionally low, 0.33 (28%/year). Highmortality rates are also indicated by tag return data.

Between 1976 and 1979 the representation ofcurrent year spawners in the Buffalo River springharvest averaged 73.1% and 56.2% for male andfemale fish respectively. Between 1983 and 1991 thisrepresentation declined significantly and averaged38A% and 21.9% for male and female fishrespectively. This observed maturity status data, theobserved 90% decrease in inconnu relativeabundance and the occurrence of recruitment failureindicated by age frequency data indicate thatexploitation regimes have substantially reduced thereproductive potential of inconnu in Great SlaveLake.

Current Harvest: Harvest levels of inconnu inGreat Slave Lake have declined from a high of 163tonnes in 1949 to an average of 3.14 tonnes per yearsince 1988. Harvest of inconnu is not controlled by aspecific quota, rather the catch is considered to be aby-catch of the lake whitefish and lake trout fishery.However, a spring fishery specifically targetsinconnu. In an attempt to regulate this fishery, an areaclosure within 2 km of the mouth of the Buffalo Riverwas imposed in 1983, but enforcement has beendifficult and the measure has been ineffective,

Other Impacts: Impacts of other activities oninconnu in Great Slave Lake are minimal. While asignificant subsistence fishery existed until the early1970s, recent harvest levels have been very low.Harvesting by sport fisheries is also very low.Industrial activities around Great Slave Lake areminimal and pollution is likely not a factor in stockfailure.

Major Issues:

The inconnu fishery is important to localfishermen. In a petition presented to the Great SlaveLake Advisory Committee in 1992 by the area fisher-men, the closure around the mouth of the BuffaloRiver was perceived as ineffective, and the fishermenrequested a change in the fishing season to protect theinconnu and allow a recovery of the stock(s).

25

Assessment

Stock Prognosis: The Buffalo River inconnustock is apparently in a very depleted state andremains so by overfishing. Low CPUE, declining sizeand age, successive year class failures, lowreproductive potential and high mortality rates allindicate the stock cannot sustain the present fishingpressure. If the harvesting continues at the presentrate, the Buffalo River inconnu stocks maycompletely fail as apparently happened in other riversin the western Great Slave Lake basin.

Management recommendations:

1. It is recommended that fishing be closed in thespring (May and June) in Areas IE, IW, III, andV to protect not only the Buffalo River, but alsothe Hay, Little Buffalo, Slave and Taltson Rivers,in which the stocks may still recover. Closing ofthe fishery in all of the historic inconnu riversmay result in a larger overall stock recovery. Aspring closure would not affect the larger lakewhitefish and lake trout fishery since thesespecies are not active at this time.

2. If recommendation #1 cannot be implemented,then a 10 km radius closure at the mouth of notonly the Buffalo River, but all the historicinconnu rivers, should be considered -

3. Continued monitoring should be carried out ofthe Buffalo River stock(s) and preferably of allstocks, either through the commercial fishery if itcontinues, or through a test fishery program if thecommercial fishery is closed. This will extend theexisting data base and help determine the impactof the fishery if it continues, or the effects of theclosing of the fishery.

4. When the stock(s) have sufficiently recovered, aquota on the spring inconnu fishery should beestablished. This quota might be developedthrough negotiations between DFO, the GreatSlave Lake Advisory Committee and thefishermen.

5. If no stock recovery occurs in the rivers whereinconnu were once known to exist, areintroduction program might be considered.However, the success of such a program wouldbe dependent on an adequate knowledge of thelife history and population dynamics of inconnuin the Great Slave Lake basin and must beundertaken with the full understanding that theprospects of success are limited.

Research Requirements:

1. The information base available for makingmanagement decisions, other than 18 years ofsize/age data and harvest data, is limited. A longterm research plan for inconnu in Great SlaveLake should be developed which will eventuallyallow for the management of this species forpredictable production. This plan should includeat least the following:

- Studies of the life history of inconnu in theGreat Slave Lake drainage basin. Inparticular, determining the reasons for thefluctuations in year class success, other thanoverexploitation, are important to thisspecies.

- Identification of stocks in the Great SlaveLake Basin.

2. After some of the above questions have beenanswered, a tagging program to determine thecontribution of fish from various river systems tothe fishery should be developed andimplemented. A program using passive (Floy)tags would be practical only in conjunction withthe commercial fishery since tag recovery wouldlikely be very low in a test fishery. Active tags(VHF radio) are generally not cost effectiveunless very specific questions, such as thelocation of or fidelity to spawning sites, are beingaddressed.

Next AFSAC Review: 1997/98

QUOTA RECOMMENDATIONS FORCOMMERCIAL FISHERIES OF ANADROMOUSARCTIC CHARR, NORTHWEST TERRITORIES,1993/94.


1. The quota recommendations given in Table 1 ofthis report are endorsed.

2. Because of the large number of fisheries listed inTable 1 of the report for which current yearharvest information is not yet available, AFSACrecommends the inclusion, in future reports, ofthe previous year’s harvest records to provide aguide to actual harvests for most fisheries. Also,whenever commercial harvest statistics are notavailable, the reasons would be useful to AFSAC(e.g. not known because fishery still in progress;will never be known).

26

3. The Fish Subcommittee continues to see thevalue of applying yield models to exploitedpopulations of anadromous Arctic charr andencourages the development of a modellingapproach to such fisheries. Modelling shouldstart on fisheries for which relatively completedata sets are available and could be refined on anannual basis and extended to other fisheries asthe data bases permit.

4. Cullage is an important factor in many of thesecommercial fisheries. The efforts of staff to solvethe problem of cullage through education andenforcement are recognized by the FishSubcommittee. In the quota recommendations,cullage is generally taken to include theconversion from round to dressed weight, fishtaken on site for subsistence consumption, andspoilage. The use of a conversion factor of 0.87takes into account only conversion from round todressed weight, whereas a conversion factor of0.80 is intended to account for all three. Actualcullage is usually unknown for these fisheries,although it can be significant in cases wheretransportation is a problem.

The following additional comments andrecommendations are provided regarding specificfisheries which are detailed in Table 2:

Ekalluk River

The proposed quota of 7 500 kg for 1993/94 isendorsed. However, it is noted that samples taken in1991 and 1992 may not be free from sampling biasbecause, due to logistic necessity, they were takenfrom early in the run, and therefore, sample meansizes and ages may be larger than the true means forthe population. Thus, there may be little real evidencefor a recovery from exploitation in this population: itseems unlikely that such a population recovery wouldbe evident so soon after the cessation of intensivefishing. Additional samples from the 1993/94 catchshould be collected to determine if there is evidenceof recovery.

Kulguyak River

The population parameters for this stock aresimilar to those for other stocks which have beendeemed to have been severely overexploited. Thisfishery is probably taking fish from the Ellice Riverstock, which itself has been overexploited. Also, thisfishery has a particular problem with high cullage dueto bad weather limiting aircraft flights to transportfish. Thus, the recommended quota of 4 000 kg mayexceed the safe harvest level for this stock, especiallyif cullage is not taken into account when estimatingtotal

catch. It is therefore recommended that the quota of4 000 kg include cullage and that every effort shouldbe made to collect a biological sample from thisfishery if it takes place in the coming year.

Rankin Inlet area

The implementation of a 4 000 kg quota toprovide a recovery mechanism for tagged fish issupported.

Chesterfield Inlet area

The concept of a zonal quota system as anexperimental management plan to attempt to easeeconomic constraints on the fisheries of this area issupported.

Ikaluit River

The proposal for a 2 300 kg quota for this fisherycannot be evaluated in the absence of any newbiological data on the stock. In the interim, the statusquo should be maintained.


1. It is recommended that Central and ArcticRegion initiate a long-term population dynamicsstudy on anadromous Arctic charr in order to testthe many assumptions of population behaviourwhich form the basis of current fisheriesmanagement practices (see Bodaly et al. 1992).Also, such a study could include the experimentalexploitation of a population or populations toobserve responses to exploitation. Improvementof management practices depends on increasingthe underlying scientific understanding ofpopulation responses to exploitation.

ACKNOWLEDGMENTS

The AFSAC Executive Committee thanks D.Bodaly, R. Crawford, A. Kristofferson, J. Flannagan,E. Gyselman, G. Low and J. Lambert of the FishSubcommittee, and R. Stewart, S. Innes, P. Richard,T. Strong, H. Cleator and M. Kingsley of the MarineMammals Subcommittee for their efforts in thereview of the background documents, the preparationof the subcommittees reports and the review of thisreport; S. Cosens, S. Innes, A. Kristofferson, C. Day,D. McGowan, G. Carder, G. Low, E. Mitchell, D.Pike, R. Tallman, M. Roberge, C. Read and P.Richard for preparing the background documents: S.Cosens, R. Crawford, B.G.E. de March and

27

T. Shortt for their editing and preparation of theAFSAC annual report, R. McV. Clarke for his adviceand guidance on finalizing this report, and D-M.Glowaicki for her administrative and secretarialsupport.

REFERENCES

ANONYMOUS. 1991. Status of harp seal popula-tions in the northwest Atlantic. Canadian AtlanticFisheries Scientific Advisory CommitteeAdvisory Document 91/12. p. 3.

BELAND, P., A. VEZINA, and D. MARTINEAU.1988. Potential growth of the St. Lawrence(Quebec, Canada) beluga whale (Delphinapterusleucas) population based on modelling. J. Cons.Cons. Int. Explor. Mer 45: 22-32.

BJORGE, A., I. CHRISTIANSEN and T.0RITSLAND. 1981. Current problems andresearch related to interactions between marinemammals and fisheries in Norwegian coastal andadjacent waters. I.C.E.S. C.M. 1981/N: 18.

BODALY, R.A., S.E. COSENS, T.A. SHORTT, andR.E.A. STEWART. 1992. Report of the ArcticFisheries Scientific Advisory Committee for1989/90 and 1990/91. Can. Manuscr. Rep. Fish.Aquat. Sci. 2139: iv + 91 p.

BORN, E.W. 1987. Denmark. Progress report oncetacean research, June 1985 to June 1986 Part 1.Greenland and Denmark. Rep. Int. WhalingComm. 37: 166-168.

BORN, E.W. and F.O. KAPEL. 1986. Denmark.Progress report on cetacean research, June 1984to June 1985 Part 1. Greenland and Denmark.Rep. Int. Whaling Comm. 36: 151-153.

BOWEN, W.D., C.K. CAPSTICK and D.E.SERGEANT. 1981. Temporal changes in thereproductive potential of female harp seals(Pagophilus groenlandicus). Can. J. Fish. Aquat.Sci. 38: 495-503.

BRODIE, P.F. 1967. The biology of the beluga,Delphinapterus leucas Pallas, of CumberlandSound, Baffin Island. Unpublished M.Sc. thesis,McGill University, Montreal, Quebec.

BRODIE, P.F. 1971. A reconsideration of aspectsof growth, reproduction, and behaviour of thewhite whale (Delphinapterus leucas), withreference to the Cumberland Sound, BaffinIsland, population. J. Fish. Res. Board Can. 28:1309-1318.

CLARKE, R. McV., L. JOHNSON, G.D.KOSHINSKY, A.W. MANSFIELD, R.W.MOSHENKO and T.A. SHORTT. 1989. Reportof the Arctic Fisheries Scientific AdvisoryCommittee for 1986/87 and 1987/88. Can.Manuscr. Rep. Fish. Aquat. Sci. 2015: iv + 68 p.

COSENS, S.E., J.F. CRAIG, and LA. SHORTT.1990. Report of the Arctic Fisheries ScientificAdvisory Committee for 1989/90. Can. Manuscr.Rep. Fish. Aquat. Sci. 2063: iv + 40 p.

COSENS, S.E. and L.P. DUECK. 1988. Responsesof migrating narwhal and beluga to icebreakertraffic at the Admiralty Inlet ice-edge, N.W.T. in1986, p. 39-54. In W.M. Sackinger and M.O.Jeffries (ed.) Port and ocean engineering underarctic conditions. Vol. 2. University of AlaskaFairbanks, Fairbanks, AK.

DEMPSON, J.B. 1978. Biological assessment ofArctic charr (Salvelinus alpinus L.) stocks andsummary of the Atlantic salmon (Salmo salar L.)fishery in northern Labrador. Can. Fish. Mar.Serv. Tech. Rep. 817: 54 p.

DEPARTMENT OF FISHERIES AND OCEANS.1991. Annual summary of fish and marinemammal harvest data for the NorthwestTerritories, 1988-1989, Volume 1: v + 59 p.

DEPARTMENT OF FISHERIES AND OCEANS.1992. Annual summary of fish and marinemammal harvest data for the NorthwestTerritories, Volume 3, 1990-1991: xiv + 67 p.

DUECK, L.P. 1989. The abundance of narwhal(Monodon monoceros L.) in Admiralty Inlet,Northwest Territories, and implications ofbehaviour on survey estimates. UnpublishedM.Sc. thesis, University of Manitoba, Winnipeg,Manitoba.

HAUG, T., A.B. KROYER, K.T. NIELSSEN, K.I.UGLEND and P.E. ASPHOLM. 1991. Harp seal(Phoca groenlandica), invasions in Norwegiancoastal waters; age composition and feedinghabits. I.C.E.S. J. Mar. Sci. 48: 363-371.

HAY, K.A. 1984. The life history of the narwhal(Monodon monoceros) in the eastern Canadianarctic. Unpublished Ph.D. thesis, McGillUniversity, Montreal, Quebec.

JOHNSON, L. 1989. The anadromous Arctic charr,Salvelinus alpinus, of Nauyuk lake, N.W.T.,Canada. Physiol. Ecol. Japan, Spec. Vol. 1: 201-227.

28

KAPEL, FO. 1977. Catch of belugas, narwhals andharbour porpoises in Greenland, 1954- 75, byyear, month and region. Rep. Int. WhalingComm. 27: 507-522.

KAPEL, FO. 1982. Denmark (Greenland) progressreport on whale research June 1980 to May 1981.Rep. Int. Whaling Comm. 32: 173-174.

KAPEL, FO. 1983. Denmark (Greenland) progressreport on cetacean research June 1981 to May1982. Rep. Int. Whaling Comm. 33:203-205.

KAPEL, F.O. 1985. Denmark. Progress report oncetacean research, June 1983 to May 1984 Part 1.Greenland. Rep. Int. Whaling Comm. 35: 162-165.

KAPEL, F.O. and F. LARSEN. 1984. Denmark(Greenland) progress report on cetacean researchJune 1982 to May 1983. Rep. Int. WhalingComm. 34: 191-193.

KINGSLEY, M. 1989. Population dynamics ofthe narwhal Monodon monoceros: an initialassessment (Odontoceti: Monodontidae). J. Zool.Lond. 219: 201-208.

LARSEN, F. 1990. Denmark. Progress report oncetacean research, June 1988 to May 1989 Part 1.Greenland and Denmark. Rep. Int. WhalingComm. 40: 190-192.

MANSFIELD, A.W. 1958. The biology of theAtlantic walrus, Odobenus rosmarus rosmarus(Linnaeus) in the eastern Canadian arctic. Fish.Res. Board Can. Manuscr. Rep. Ser. (Biol.) 653:146 p.

MANSFIELD, A.W. and D.J. ST. -AUBIN. 1991.Distribution and abundance of the AtlanticWalrus, Odobenus rosmarus rosmarus, in theSouthampton Island . Coats Island region ofnorthern Hudson Bay. Can. Field-Nat. 105(1):95-100.

REILLY, S.B. and J. BARLOW. 1986. Rates ofincrease in dolphin population size. Fish. Bull.84: 527-533.

RICHARD, P.R. 1990. Status of the belugas,Delphinapterus leucas, of Southeast BaffinIsland, Northwest Territories. Can. Field-Nat.105: 206-214.

RICHARD, P.R. and R.R. CAMPBELL. 1988.Status of the Atlantic walrus, Odobenus rosmarusrosmarus, in Canada. Can. Field-Nat. 102: 337-350.

RICKER, W.E. 1975. Computation and interpreta-tion of biological statistics of fish populations.Bull. Fish. Res. Board Can. 191: 382 p.

ROBERGE, MM. and J.B. DUNN. 1990. Assess-ment of the subsistence harvest and biology ofnarwhal (Monodon monoceros L.) fromAdmiralty Inlet, Baffin Island, N.W.T.., 1983 and1986-89. Can. Tech. Rep. Fish. Aquat. Sci. 1747:32 p.

ROFF, DA. and WD. BOWEN. 1983. Populationdynamics and management of the northwestAtlantic harp seal (Phoca groenlandica). Can. J.Fish. Aquat. Sci. 40: 919-932.

ROFF, D. and WD. BOWEN. 1986. Further analysisof population trends in the Northwest Atlanticharp seal (Phoca groenlandica) from 1967 to1985. Can. J. Fish. Aquat. Sci. 43: 553-564.

SERGEANT, D.E., and PF. BRODIE. 1969. Bodysize in white whales, Delphinapterus leucas. J.Fish. Res. Board Can. 26: 2561-2580.

SNEDECOR, G.W, and W.G. COCHRAN. 1967.Statistical methods, 6th ed. Iowa State UniversityPress, Ames, IO. 593 p.

STRONG, J.J. 1988. Status of the narwhal,Monodon monoceros, in Canada. Can. Field-Nat. 102: 391-398.

von BERTALANFLY, L. 1938. A quantitative theoryof organic growth (inquiries on growth laws II).Human Biol. 10: 181-213.

WAGEMANN, R, SNOW, N.B., LUTZ, A. and D.P.SCOTT. 1983. Heavy metals in tissues andorgans of the narwhal (Monodon monoceros).Can. J. Fish. Aquat. Sci. 40: 206-214.

WEAVER, P.A. and R.W. WALKER. 1988. Thenarwhal

(Monodon monoceros L) harvest in Pond Inlet,Northwest Territories: hunt documentation andbiological sampling, 1982-1983. Can. Manuscr.Rep. Fish. Aquat. Sci. 1975: iv + 26 p.

WINTERS, G.H. 1988. The development and utilityof sequential population analysis. In Rivard, D.(editor). Collected papers on stock assessmentmethods. CAFSAC Research Document 88/61.

29

Table 1. 1991/92 quotas and harvest, 1992/93 quotas and harvest, and 1993/94recommended quotas for the anadromous Arctic charr commercial fisheries in theNorthwest Territories. Regions and numerical designations of water bodies followsthat of Schedule V. Northwest Territories Fishery Regulations. Quotas and harvestfigures are in kilograms, round weight. Quotas in brackets are equivalent dressedweight. For quotas marked *, round to dressed weight conversion factor is 0.80.This includes an estimate for subsistence take and cullage. For all other quotas,conversion factor is 0.87 because data on subsistence take and cullage are notavailable for these fisheries. (NF = not fished: NA = not available at present; S =biological sample taken during fishing year; not opened = no interest expressed infishing that year; closed = available information indicates that fishing should nottake place that year). No changes are recommended for most stocks in either yearbecause no additional information was available, catch for effort indicated thatstocks were not in trouble, or no significant changes were noted when results ofbiological samples were compared with the previous year. Changes wererecommended for stocks marked **, and details of these are given in Table 2.

Waters 1991/92Quota/Harvest

1992/93Quota/Harvest

1993/94Quota

REGION I - MACKENZIE DELTA

9. Hornaday River closed closed closed12. Mackenzie River closed closed closed

REGION IV - CENTRAL ARCTIC

1. Agnew River Area 4 500/NF 4 500/NF 4 500 (3 900) 2. Arrowsmith River 1 000/998 1 000/198 (S) 1 000 (900) 3. Becher River 1 000/808 1 000/504 1 000 (900) 6. Coppermine River 600/581 (S) 600/603 600 (500) 7. Curtis River 4 500/268 4 500/NF 4 500 (3 900) 9. Ekalluk River closed/ (S) 7 500/NF (S) 7 500 (6 000)**10. Ellice River 8 000/7 971 (S) 8 000/NF 8 000 (6 400)* 13. Halovik River 6 800/7 354 (S) 6 800/6 872 6 800 (5 500)* 14. Jayco River 15 600/2 225 (S) 15 600/NF 15 600 (12 500)* 16. Kagloryuak River not opened not opened 1 000 (900) 17. Keith Bay 4 500/449 4 500/301 4 500 (3 900) 18. Kellett River 1 000/682 1 000/686 (S) 1 000 (900) 20. Kulguyak River 8 000/3 852 4 000/NF 4 000 (3 200)** 21. Kuujjua River 600/NA not opened 600 (500) 22. Lachlan River 9 100/8 807 (S) 9 100/9 320 (S) 9 100 (7 300)* 23. Lord Lindsay Lake 2 500/2 920 2 500/2 407 (S) 2 500 (2 200) 25. Murchison River 9 100/NF 9 100/NF 9 100 (7 900) 26. Norway Bay 2 500/NF 2 500/NF 2 500 (2 200)

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Table 1. cont.....Waters 1991/92

Quota/Harvest1992/93

Quota/Harvest1993/94Quota

REGION IV - CENTRAL ARCTIC cont...

27. Paliryuak River 9 100/8 953 (S) 9 100/8 884 (S) 9 100 (7 300) 29. Perry River 6 500/601 (S) 6 500/HF 6 500 (5 200) 30. Port Parry 1 000/745 1 000/245 1 000 (900) 32. Simpson River 4 500/HF 4 500/HF 4 500 (3 900) 33. Stanwell-Fletcher 6 800/2 144 6 800/HF 6 800 (5 900) 36. Thomsen River not opened not opened 1 400 (1 200) 40. Unnamed River closed closed closed 41. Unnamed River not opened not opened 2 500 (2 200) 142. Unnamed River not opened not opened 900 (800) 143. Unnamed River not opened not opened 4 500 (3 900) 144. Unnamed River not opened not opened 4 500 (3 900)

REGION V - KEEWATIN

1. Alden Lake and R. not opened not opened 900 (800) 4. Baker Foreland 4 600/2 648 4 600/1 143 (5) 4 600 (4 000) 7. Belcher Islands closed closed closed 8. Bennett Bay, Wager 2 300/100 2 300/HF 2 300 (2 000) 9. Big River not opened not opened 900 (800) 13. Brown River 6 800/HF 6 800/HF 6 800 (5 900) 16. Chest. Inlet, Fish Bay 4 500/4 611 4 500/2 972 closed**17. Churchill River Area 500/HF 500/HF 500 (400) 18. Christie Lake not opened not opened 900 (800) 19. Cleveland River Area (summer) 6 100/572 6 100/1 949 6 100 (5 300) (winter) 3 000/200 3 000/NA 3 000 (2 600) 20. Copperneedle River 4 500/781 4 500/290 4 500 (3 900) 21. Corbett Inlet 4 500/2 130 4 500/32 4 500 (3 900) 24. Diana Lake closed closed closed 26. East Point not opened not opened closed**28. Eskimo Point Area 4 500/958 4 500/87 4 500 (3 900) 29. Ferguson River 13 000/4 589 13 600/1 014 13 600 (11 800) 32. Gibson Cove not opened not opened 2 300 (2 000) 33. Gordon River not opened not opened 1 100 (1 000) 34. Gore Bay 3 600/150 3 600/HF 3 600 (3 100) 36. Hanway River not opened not opened closed**37. Haviland Bay Area 2 300/1 300 2 300/HF 2 300 (2 000) 39. Josephine River closed closed closed40. Kamarvik Creek not opened not opened 2 300 (2 000) 45. Maguse River 4 500/668 4 500/122 4 500 (3 900) 48. Merle Harbour 2 300/771 2 300/HF closed**49. Mistake Bay 2 300/544 2 300/80 2 300 (2 000) 51. North Pole River 2 300/127 2 300/HF 2 300 (2 000) 57. Peter Lake closed closed closed

31

Table 1. cont.....Waters 1991/92



REGION V - KEEWATIN cont...

58. Piksimak River 2 300/150 2 300/NF 2 300 (2 000) 59. Pistol Bay 2 300/841 2 300/177 2 300 (2 000) 63. Ranger Seal Bay 9 100/2 000 9 100/NF closed*64. Rankin Inlet Area 5 000/5 550 4 000/1 457 4 000 (3 500)**65. Robin Hood Bay 6 800/NF 6 800/NF 6 800 (5 900) 66. Sandy Point 900/638 900/599 900 (800) 69. Snowbank River 2 300/75 2 300/NF 2 300 (2 000) 71. Steep Bank Bay 4 500/1 654 4 500/NF closed**72. Stoney Point Area 6 800/916 6 800/NF 6 800 (5 900) 75. Thomsen River 8 400/NF 8 400/NF 8 400 (7 300) 2-yr76. Wallace River 2 300/NF 2 300/601 2 300 (2 000) 77. Whal e Cove Area closed closed closed79. Wilson Bay (summer) 8 000/2 491 8 000/1 121 8 000 (7 000) (winter) 2 000/NA 2 000/NA 2 000 (1 700) 81. Unnamed River 2 300/HF 2 300/NF 2 300 (2 000) 82. Unnamed River 2 300/NF 2 300/NF 2 300 (2 000) 83. Unnamed River 6 800/HF 6 800/NF closed**84. Unnamed River not opened not opened closed**85. Unnamed River not opened not opened closed**

REGION VI - BAFFIN - HIGH ARCTIC 1. Adams Island Lake and not opened not opened 700 (600) 2. Amadjuak Lake not opened 9 100/NF 9 100 (7 900) 5. Blandford Bay River not opened not opened 900 (800) 7. Cape Adair Lake and R. not opened 2 300/HF 2 300 (2 000) 9. Clyde Inlet not opened/700 2 300/NF 2 300 (2 000) 10. Cockburn River 5 000/HF 5 000/HF 5 000 (4 400) 11. Coutts Inlet 900/NF 900/HF 900 (800) 13. Duart Lake not opened 700/HF 700 (600) 14. Eque Bay Area not opened not opened 900 (800) 16. Feacham Bay Lake not opened not opened 900 (800) 18. Gifford River 3 600/HF 5 000/7 321 5 000 (4 400) 19. Hall Lake 11 400/6 670 11 400/2 268 11 (9 900) 21.1 Ijaruvung Lake 2 000/1 432 2 000/1 791 2 000 (1 700) 21.2 Ikaluit Lake R. Peel In. 1 400/1 400 1 400/1 182 1 400 (1 200) 21.3 Iqaluit River 2 300/2 390 2 300/2 300 2 300 (2 000)**21.4 Ikalukjuak L. and R. not opened not opened 1 400 (1 200) 21.5 Ikikeesarjuk Lake 2 000/1 697 2 000/186 2 000 (1 800) 21.6 Ikpik R., L. Gillian not opened not opened 3 200 (2 900) 21.7 Ikpikiturjuaq Lake not opened not opened 1 100 (1 000) 21.8 Iqallujjuaq Fjord not opened 1 400/364 1 400 (1 200) 22. Irvine Inlet not opened 4 500/1 024 4 500 (3 900)

32

Table 1.....Waters 1991/92



REGION VI - BAFFIN - HIGH ARCTIC cont...

23. Isortog River and L. not opened not opened 5 000 (4 400)23.1 Kangisuajuq L. not opened/500 2 700/49 2 700 (2 300) 24. Kingnait Fjord 4 500/4 545 4 500/4 955 4 500 (3 900) 26. Kukaluk River 3 600/HF 3 600/2 496 3 600 (3 100)26.1 Kuutannak River not opened not opened 1 400 (1 200) 27. Lethbridge Lake not opened not opened 1 400 (1 200)27.1 Magda River 3 000/3 090 3 000/287 3 000 (2 600) 30. Newton Fjord Area not opened 2 300/HF 2 300 (2 000) 31. Nettilling Lake 22 000/300 22 000/3 450 22 000 (19 000) 32. Nudlung Fjord 4 500/150 4 500/3 160 4 500 (3 900) 33. Okalik Bay not opened 1 400/HF 1 400 (1 200)33.1 Opingivik Lake 1 000/1 114 1 000/1 013 1 000 (900) 35. Padle Fjord 3 600/3 916 3 600/6 471 3 600 (3 100) 36. Padloping Island not opened not opened 900 (800) 37. Paquet Bay R. and L. not opened 1 000/HF 1 000 (900) 38. Phillips Creek closed closed closed 39. Piling L. and R. 1 800/HF not opened 1 800 (1 600) 41. Qualluatik Lake not opened 700/HF 700 (600) 42. Ravn River 5 000/HF 9 100/9 215 5 000 (4 400) 43. Rowley River 5 000/HF 5 000/HF 5 000 (4 400) 44. Sam Ford Fjord not opened/816 3 600/3 600 3 600 (3 100) 45. Saputing River 9 100/5 189 9 100/8 013 9 100 (7 900)45.1 Tarrionituk Lake not opened 4 500/HF 4 500 (3 900) 46. Tarsuaq Arm R. and L. not opened not opened 2 500 (2 200) 47. Tasialojuak Lake closed 4 500/HF 4 500 (3 900)47.1 Tinitonito Lake 5 500/1 100 5 500/289 5 500 (4 800) 48. Tugaat River and L. 1 000/HF 1 000/HF 1 000 (900) 50. Whyte L. and R. 900/HF 900/HF 900 (800) 51. Unnamed River not opened not opened 900 (800) 53. Unnamed River not opened not opened closed 59. Unnamed Lake and 2 300/1 900 2 300/1 773 2 300 (2 000) 60. Unnamed R. and L. not opened not opened 500 (400) 61. Unnamed L. and R. not opened not opened 900 (800) 62. Unnamed River 2 500/HF not opened/NA 2 500 (2 200)

33

Table 2. Recommended changes to commercial fishing quotas for anadromous Arctic charr in theNorthwest Territories, 1992/93 and/or 1993/94.

REGION IV - CENTRAL ARCTIC

9. Ekalluk River

Declining size and age of charr in samples from the commercial catch over the period 1986 to1990 led to a recommendation to reduce the 1991 quota to 7 500 kg from the previous 14 500 kg.This recommendation was discussed with members of the Ikaluktutiak Cooperative inCambridge Bay by DFO Area staff prior to the 1991 fishing season. The Coop represents thecommercial fishermen in the community. The fishermen requested that the commercial fishery beclosed entirely for that year to ease pressure on the stock, rather than fish at a reduced quota.DFO complied with their wishes and did not open the fishery in 1991. The quota was opened for7 500 kg in 1992 but was not fished for economic reasons. However, DFO staff set experimental(commercial size) gillnets in the river and obtained a biological sample in 1991 and 1992 tomaintain continuity of the sampling record. A seven-year summary of sample results is presentedbelow:

YEAR MEAN FL (MM) MODAL FL (MM) MEAN AGE (Y) MODAL AGE (Y)

1986 701 700-750 14.9 14

1987 684 650-700 15.2 15

1988 611 600-650 13.9 14

1989 640 600-650 13.6 14

1990 621 600-650 12.7 12

1991 662 700-750 12.6 11

1992 685 650-700 13.9 14

Although data from the 1991 sample indicated that the mean size increased from 1990, thesample may have been biased because it was taken at the start of the upstream run.

Also, results from previous tagging programs indicate that some charr tagged in the upstream runin the Ekalluk River were subsequently taken at other commercial fishing sites in WellingtonBay. Therefore, although the Ekalluk River remained closed for the 1992 season, there is apossibility that some charr from that stock were taken by adjacent fisheries. Regardless, thisstock has been exploited at a lower level during the past two years and the samples suggest that ithas recovered to some extent. A sample of the 1993/94 catch should be taken to determine ifthere is evidence of a stock recovery.

34

REGION IV - CENTRAL ARCTIC .......

20. Kulguyak River

This fishing location was opened in 1991 after a hiatus of at least 12 years. The original requestwas for a quota of 1 500 kg. However, the decision by the Ikaluktutiak Cooperative not to fishthe Ekalluk River in 1991 led to a request to increase the quota to 8 000 kg at this location. Thequota may have been reached but only 3 852 kg was delivered to the plant in Cambridge Bay.This was apparently due to very bad weather which severely affected flights into the fishing siteto pick up the catch. Rather large cullage at the site is suspected. More important, the fishery tookplace along the coast instead of at the river mouth. A biological sample of the catch showedmean length was 667 mm and mean age was 11.1 years. Modal size was 600-650 mm and modalage was 11 years. Instantaneous total mortality (Z) for ages 12-14 years was 0.73. This mortalityis high for a stock that has apparently not been exploited for a long time. This observation, plusthe coastal location of the fishing site suggests that some of the catch may have been itinerantcharr from another system. The Ellice River is adjacent to this location to the east. It wasrecommended that the quota for the Kulguyak River be reduced to 4 000 kg for the 1992 seasonas a precautionary measure to prevent overexploitation of the Ellice River stock. Due toeconomic reasons, this fishery did not take place in 1992. However, the recommended quota of 4000 kg remains for 1993/94. A tagging program is recommended to determine stock structure.

REGION V - KEEWATIN

64. Rankin Inlet Area

This fishery took place in 1992 as part of a tagging study of Arctic charr in the nearby DianaRiver. The study was designed to determine whether there was evidence of over-exploitation ofthis stock and to provide an estimate of the subsistence harvest at Rankin Inlet. See AFSACDOCUMENT 1991/92-06 for details. The success of the tagging program was limited due to avery late breakup and the fishery was not very successful either. An attempt will be made torepeat the tagging program in 1993. Therefore, the commercial fishery with a quota of 4 000 kgis recommended to provide a recovery mechanism for the tagged charr.

16. Chesterfield Inlet, Fish Bay, 26. East Point, 48. Merle Harbour, 36. Hanway River, 63.Ranger Seal Bay, 71. Steep Bank Bay, Unnamed Rivers 83., 84., and 85.

A multi-year experimental program will be carried out in the Chesterfield Inlet area to determinethe feasibility of a mixed-stock fishery to overcome severe economic constraints. A zonal quotasystem, including open water commercial fishing zones and subsistence fishing zones wasdevised at a community workshop. These zones will replace the regular schedule fisheries.Tagging programs will be conducted so that stocks can be identified and exploitation ratescalculated. Fishermen will maintain logbooks and record CPUE and economic data.

35

REGION VI - BAFFIN - HIGH ARCTIC

21.3 Iqaluit River

This stock is currently under investigation and the recommended quota may change. Further dataanalyses are pending. In the interim, the status quo will be maintained.

36

Table 3. Comparison of data required for managing marine mammals on the basis ofreplacement yield (RY), on the population’s position between maximum netproductivity level and carrying capacity, (MNPL- K) and on optimum sustainablepopulation level (OSP) measures. (+ indicates all marked parameters are needed,= indicates some of the parameters are needed).

Data Required Management Approach

RY MNPL-K OSP

stock identity + + + harvest level + + + age of maturity + = reproductive rates + = breeding ratios + = natural mortality + = hunting mortality + = age structure + = population size + + = past age structure + past population size + carrying capacity + MNPL:K + relative population responses + + = including: antagonistic behaviour = displacement behaviour = foraging time = time tending young = dietary components = physical condition = growth = incidence of infection = rate of population change = effects on habitat =

37

38

Appendix 1. List of AFSAC Background Documents for 1991/92 and 1992/93.

1991/92 Background Documents

91/92-01 High Arctic Narwhal. S. Cosens.

91/92-02 Arctic Charr of the Sylvia Grinnell River. D. Pike.

91/92-03 Stock Status of Arctic Charr, Ikaluit River, Baffin Island, Northwest Territories.M. Roberge and C. Read.

91/92-04 S.E. Baffin Beluga Stock. P. Richard.

91/92-05 Quota Recommendations for Commercial Fisheries of Anadromous Arctic Charr,Northwest Territories, 1992/93. A.H. Kristofferson, G. Low and D. Pike.

91/92-06 Stock Status of Arctic Charr in the Diana River, Northwest Territories. A.H.Kristofferson, D.K. McGowan, G.W. Carder and R.F. Tallman.

91/92-07 1991 Clearwater Fiord Beluga Survey. D. Pike.

91/92-08 The Great Slave Lake Commercial Lake Whitefish, Coregonus clupeaformis,fishery. A.C. Day and G. Low.

39

1992/93 Background Documents

92/93-01 Harp Seal (Phoca groenlandica) S. Innes.

92/93-02 Summer Distribution and Abundance of Walrus in Northern Hudson Bay,Western Hudson Strait and Foxe Basin; 1988-1990. P. Richard.

92/93-03 Preliminary Report to AFSAC on the Cliff-top Survey of Whales in ClearwaterFiord, Cumberland Sound. S. Innes.

92/93-04 Stock Status of Arctic Charr in the Kuujjua River, Northwest Territories. L.Harwood.

92/93-05 Stock Status of Arctic Charr in Freshwater Creek, Northwest Territories. A.H.Kristofferson, D.K. McGowan, G.W. Carder, and G. Low.

92/93-06 Quota Recommendations for Commercial Fisheries of Anadromous Arctic Charr,Northwest Territories 1993/94. A.H. Kristofferson, G. Low and D. Pike.

92/93-07 The Great Slave Lake Commercial Inconnu Stenodus leucichthys, Fishery. A.C.Day and G. Low.

92/93-08 Biological and Ecological Effects of Net Fisheries for Monodontid Whales in theCanadian Arctic. M. Kingsley.

40

Appendix 2. List of AFSAC Background Documents by species from 1986 to 1992/93.

SPECIES BACKGROUND DOCUMENT # TITLE/AUTHOR(S)

FISH SUBCOMMITTEE

Arctic Charr 86/87-10 Status Report on Searun Arctic CharrStocks in the Northwest Territories.A. Kristofferson, G. Low, L. Dahlke,E. Gyselman and L. Johnson.

87/88-01 Stock Assessment for Arctic Charr inthe Steensby Inlet Area, N.W.T.M.M. Roberge.

87/88-05 Stock Status of Arctic Charr in theFirth River, Yukon Territory.A.H. Kristofferson and R.F. Baker.

87/88-06 Stock Status of Arctic Charr in theBabbage River, Yukon Territory.A.H. Kristofferson and R.F. Baker.

87/88-07 Stock Status of Arctic Charr in theRat River, Northwest Territories.A.H. Kristofferson and R.F. Baker.

87/88-08 Stock Status of Arctic Charr in theBig Fish River, NorthwestTerritories. A.H. Kristofferson andR.F. Baker.

87/88-09 Stock Status of Arctic Charr in theHornaday River, NorthwestTerritories. A.H. Kristofferson.

87/88-10 Stock Status of Arctic Charr in theKuuk River, Northwest Territories.A.H. Kristofferson.

87/88-11 Stock Status of Arctic Charr inFreshwater Creek, NorthwestTerritories. A.H. Kristofferson,G. Carder, D.K. McGowan and G. Low.

87/88-12 Recommended Commercial FishingQuotas in the Northwest Territories1988/89. A. Kristofferson,L. Dahlke and G. Low.

88/89-09 Quota Recommendations for CommercialFisheries of Anadromous ArcticCharr, Northwest Territories,1989/90. A.H. Kristofferson,G. Low, D. Pike and B. Stewart.

88/89-10 Stock Status Report of Arctic CharrCommercial Fisheries of CambridgeBay, Northwest Territories.A.H. Kristofferson, D. McGowan,G. Carder and G. Low.

41

89/90-10 Stock Status of Arctic Charr in theKagluk R., N.W.T. P. Lemieux.

89/90-11 Stock Status of Arctic Charr in theRat R., N.W.T. P. Lemieux andA. Kristofferson.

89/90-12 Stock Status of Arctic Charr in theHornaday R., N.W.T. P. Lemieux andA. Kristofferson.

89/90-13 Annual Summary Arctic Charr inN.W.T. A. Kristofferson.

89/90-14 Arctic Charr: Keewatin.A. Kristofferson.

90/91-03 Stock Status of Arctic Charr in theNaloagyok River, NorthwestTerritories. P. Lemieux.

90/91-04 Stock Status of Arctic Charr in theKagloryuak River, NorthwestTerritories. P. Lemieux.

90/91-05 Arctic Charr of the Sylvia GrinnellRiver. D. Pike and L. Dahlke.

90/91-06 Annual Summary Arctic Charr inN.W.T. A. Kristofferson.

90/91-08 Commercial Fishing Potential forSearun Arctic Charr, Koukdjuak Riverand Nettilling Lake, Northwest Territories.

91/92-02 Arctic Charr of the Sylvia GrinnellRiver. D. Pike.

91/92-03 Stock Status of Arctic Charr,Ikaluit River, Baffin Island,Northwest Territories. M. Robergeand C. Read.

91/92-05 Quota Recommendations for CommercialFisheries of Anadromous ArcticCharr, Northwest Territories,1992/93. A.H. Kristofferson, G. Lowand D. Pike.

91/92-06 Stock Status of Arctic Charr in theDiana River, Northwest Territories.A.H. Kristofferson, D.K. McGowan,G.W. Carder and R.F. Tallman.

92/93-04 Stock Status of Arctic Charr in theKuujjua River, NorthwestTerritories. L. Harwood.

92/93-05 Stock Status of Arctic Charr inFreshwater Creek, NorthwestTerritories. A.H. Kristofferson,D.K. McGowan, G.W. Carder, andG. Low.

92/93-06 Quota Recommendations for CommercialFisheries of Anadromous ArcticCharr, Northwest Territories

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1993/94. A.H. Kristofferson, G. Lowand D. Pike.

Walleye 86/87-06 Status of the Walleye Utilizing theHay River, Northwest Territories.M.M. Roberge and G. Low.

86/87-07 Status of the Walleye Stock fromTathlina Lake, NorthwestTerritories. M.M. Roberge andG. Low.

86/87-08 Status of the Walleye Stock fromKakisa Lake, Northwest Territories.M.M. Roberge and G. Low.

86/87-09 Status of the Walleye StockUtilizing the Mosquito Creek,Northwest Territories. M.M. Robergeand G. Low.

87/88-04 The Walleye of Mosquito Creek,Northwest Territories.M.M. Roberge.

Lake Trout 86/87-05 Status of Lake Trout in Great BearLake, N.W.T. G. Yaremchuk andM.M. Roberge.Update on the Status of Lake Troutin Great Bear Lake, NorthwestTerritories. M.M. Roberge.

Broad Whitefish 87/88-02 Interim Report on the Status of theBroad Whitefish (Coregonus nasus)Stocks of the Lower Mackenzie Basin.R.F. Baker.

88/89-01 Status Report on Broad WhitefishStocks of the Lower Mackenzie Basin,Northwest Territories. R.F. Bakerand J.D. Reist.

Lake Whitefish 89/90-04 Lake Whitefish: Chitty Lakes.E. Gyselman.

91/92-08 The Great Slave Lake Commercial LakeWhitefish, Coregonus clupeaformis,Fishery. A.C. Day and G. Low.

Arctic cisco 88/89-02 Arctic Cisco, Coregonus autumnalis,in the Mackenzie River Basin, StockStatus Report. W.A. Bond andJ.D. Reist.

Inconnu 92/93-07 The Great Slave Lake CommercialInconnu Stenodus leucichthys,Fishery. A.C. Day and G. Low.

43

Greenland Turbot 88/89-04 Greenland Halibut of the InshoreEastern Arctic. R. Crawford andL. Dahlke.

89/90-09 Update of the Baffin Island TurbotFishery. R. Crawford.

89/90-09A Greenland Halibut Allocation:Baffin Region. D. Pike.

90/91-02 On the Davis Strait/Cumberland SoundGreenland Halibut (Reinhardtiushippoglossoides Walbaum): ItsBiology and its Fisheries.R. Crawford.

Iceland Scallops 88/89-07 Iceland Scallops in the EasternArctic. R. Crawford.

89/90-07 Biology of Iceland Scallops and ItsImplications for the Management of anArctic Fishery. R. Crawford and C. Hudon.

89/90-08 A Preliminary Analysis of the 1988Cumberland Sound Iceland ScallopFishery. R. Crawford and D. Pike.

MARINE MAMMALS SUBCOMMITTEE

Beluga 86/87-11 Status of the Sub-arctic Beluga(Delphinapterus leucas) Populationsin the Northwest Territories andNorthern Quebec. P.R. Richard.

87/88-13 Status Report: Beaufort Sea Beluga.J.T. Strong.

88/89-06 Status of the Western Hudson BayBeluga (Delphinapterus leucas)Populations. P.R. Richard.

88/89-08 Stock Status Sheet Southeast BaffinBeluga (Delphinapterus leucas).R. Stewart.

89/90-01 Beaufort Sea Beluga. T. Strong.89/90-02 Ungava Bay and Eastern Hudson Bay

Beluga. R. Reeves and E. Mitchell.89/90-06 Lancaster Sound Beluga Whales.

S. Cosens and R. Stewart.90/91-07 Eastern Hudson Bay Beluga.

T. Smith.91/92-04 S.E. Baffin beluga stock.

P. Richard.91/92-07 1991 Clearwater Fiord Beluga Survey.

D. Pike.92/93-03 Preliminary Report to AFSAC on the

Cliff-top Survey of Whales inClearwater Fiord, Cumberland Sound.S. Innes.

44

Narwhal 86/87-13 Status of the Narwhal, Monodonmonoceros, in Canada. J.T. Strong.

87/88-14 Northern Hudson Bay Narwhal Stock.P.R. Richard.

88/89-05 Status of the Narwhal, Monodonmonoceros, in Canada. J.T. Strong.

91/92-01 High Arctic Narwhal. S. Cosens.

Bowhead 88/89-11 Stock Status Report on CanadianArctic Bowhead Whales.E.D. Mitchell.

89/90-03 Review of the Estimated Stock Sizefor the Western Arctic BowheadWhale. S. Innes.

Walrus 86/87-12 Status of Walrus (Odobenus rosmarus)in Canada. P.R. Richard.

92/93-02 Summer Distribution and Abundance ofWalrus in Northern Hudson Bay,Western Hudson Strait and FoxeBasin; 1988-1990. P. Richard.

Ringed Seal 87/88-15 Status of the Ringed Seal in Canada.M.C.S. Kingsley.

89/90-05 Ringed Seal. S. Innes.

Bearded Seal 90/91-01 Bearded Seal. H. Cleator.

Harp Seal 92/93-01 Harp Seal (Phoca groenlandica)S. Innes.

GENERAL TOPICS86/87-01 Arctic Fisheries Scientific Advisory

Committee, Terms of Reference andOperating Procedures, July 1986.Position Paper on the ArcticFisheries Scientific AdvisoryCommittee, April 1987.

86/87-02 Studies on the Systematics andPopulation Structure of ArcticMarine, Anadromous, and FreshwaterFishes. A Justification andStatement of Need for Research.J.D. Reist.

86/87-03 Exploitation of Arctic Fishes.R. Crawford.

86/87-04 Limnology, Oceanography andFisheries Research. The View fromthe Arctic Window. L. Johnson.

88/89-03 Review of Keewatin Lakes.L. Johnson.

45

89/90-15 Framework for Making Management andResearch Recommendations by theAFSAC Marine Mammal Subcommittee:Objectives, Data Requirements andDefinitions of Terms. S. Cosens,S. Innes, P. Richard, R. Stewart andT. Strong.

92/93-08 Biological and Ecological Effects of NetFisheries for Monodontid Whales in theCanadian Arctic. M. Kingsley.

46

Appendix 3. Glossary of terms used in the reports by the AFSAC Marine MammalsSubcommittee for 1991/92, 1992/93 and earlier years. The following definitionshave been agreed upon by the AFSAC Marine Mammals Subcommittee andapply to the reports by that Subcommittee contained in this report, as well asfuture reports by that Subcommittee for AFSAC.

95% Confidence Interval: Represents the upper and lower bounds of a regime that contains thetrue mean 19 times out of 20 samplings.

Abundance estimate: Uses abundance in an incorrect fashion. An abundance is a plentitude.However, an abundance estimate in colloquial terms is the estimate of the number of animalsinhabiting the area sampled during a population survey.

Age at first ovulation: This reproductive parameter which is a more precise measure of age ofmaturity should be estimated with some measure of central tendency, variance and sample size.The technique used to identify age and ovulations should be described and biases discussed.Normally it is expressed in years and often a range is more accurate.

Age at first pregnancy: This parameter should be estimated with some measure of centraltendency, variance and sample size. The technique used to identify age and pregnancy should bedescribed and biases discussed.

Age structure of population: This is estimated from the frequency distribution age classes,usually individuals sampled from the stock. The ageing method should be identified. Authorsmust also discuss the sex and age bias of the sampling procedure so that interpretation ofdifferences between samples is not confounded by differences in sampling procedure.

Axillary blubber thickness: There are 3 blubber thicknesses measured on the axillary girth (girthat the “armpit”): dorsal, lateral and vertical.

Fatness: This variable is estimated by measuring blubber thickness and amount of core fat.Gender, reproductive status (e.g. pregnant, lactating) and nutritional status (e.g. fasting) ofindividuals and the date samples were collected must be included. This is an important variablethat is not measured and reported on in all samplings, however, it should be.

Finite rate of increase (er): This variable is population growth rate calculated from age specificfecundities (the number of female calves born in one year per female of a given age class in theprevious year) and survival rates (the percentage of individuals in any given age class thatsurvive to enter the next age class) (Reilly and Barlow 1986). At small values of r, er isapproximately equal to 1 - r where r is the instantaneous rate of increase expressed as apercentage of total population per year. Values of r, used for narwhal and belugas have beenderived from population models (Beland et al. 1988; Kingsley 1989; Reilly and Barlow 1986).Those used for some pinnipeds, such as the ringed seal, have been derived from ‘age at harvest’studies. Authors should indicate how estimate was derived.

47

Haulout site: A location either on land or ice where walrus leave the water.Several hundred animals may congregate at these sites.

Iqunuk: Fermented walrus meat, blubber, liver and intestine.

Index: An index is a measurable quantity which is related to but not equal to the quantity ofinterest. A population index is an observation concerning the size of the population which isrelated to the total number of individuals in the population.

Maximum daily counts: The largest number of animals counted during a single day.

Mean body length: Is the average body length calculated by adding all the body lengths togetherand dividing by the number of body lengths in the sum.

Modal body length: Is the most frequently occurring body length. It often represents a mostfrequent class of lengths, such as between 60-69.9 cm and not the actual measurement such as60.54.

Optimum Sustainable Yield(s): A yield that is at or below the replacement yield of the stock.Optimum refers to the maximization of the yield under a number of constraints. In the UnitedStates OSY refers to the range of possible yields from a stock between its Maximum NetProductivity Level and its carrying capacity.

Pregnancy rate: This is the percent of pregnant females relative to the total number of sampledadult females. The date when samples were collected should be included because the value ofestimate will depend upon the time of year where samples were collected. Other variables such asbirth rate or calving rate could also be reported, but the method, date of the sample and adiscussion of biases also need to be included.

Probability density function (distribution): This is a mathematical or graphical presentation of theprobability of an event occurring in relation to some other observation. For example, theprobability that the next whale seen will be at 1.15 km from the airplane.

Reproductive status: Immature, pregnant, lactating, etc.

Savssat: Ice entrapment.

S.E. (standard error): This is the standard deviation (sx) of the mean (0) as described in Snedecorand Cochran (1967; p. 50). It is estimated as sx//n.

Stock: Cetacean stocks are identified by their areas of summer concentration, to avoiduncertainty about the degree of genetic mixing in the wintering area. Local declines of whalesusing particular estuaries suggest this to be a useful management approach (Reeves and Mitchellin press). Pinniped stocks may be similarly defined. For example, ringed seals are continuouslydistributed across the arctic but can be depleted on a local level, at least temporarily. The area oflocal depletion should therefore define the stock.

48

Stock distribution: The distribution or geographic range of the stock includes the summering,migration and wintering locations. Spatial and temporal overlap with other stocks should beidentified, if known or suspected. Authors should indicate how stock identification has beencarried out. Any terminology used to identify methods, e.g. body length or girth should beoperationally defined such that data sets for different stocks can be readily compared byindividuals elsewhere.

Stock size: The number of individuals in a stock is estimated using some measure of centraltendency and an estimate of variance, such as a 95% Confidence Interval, calculated fromsurveys, mark-recapture or some other acceptable method. Authors should indicate whether thevalue includes a correction factor, its variance and how the correction factor alters theuncorrected estimate. Potential biases in sampling design or method should also be identified.

Struck and lost rate: This variable is estimated by the total animals struck and wounded but notlanded during a hunt, and is expressed as a percent of the total number of animals struck.Assuming that all animals struck and lost are removed from the population:

landed animals = Total removal - (total removal × loss rate)

This equation can also be expressed as:

Total removal = landed × 1 1-loss rate

A preferred measure of hunting loss is the ‘killed and lost’ rate, calculated in a similar way. Thenumber killed must then be estimated by assessing whether a lost animal was mortally woundedor not. Whichever estimate is used, some explanation of assumptions used in deriving theestimate should be included. For example, are all animals struck and lost assumed to be removedfrom the stock?

Total Allowable Removal (TAR): The total number of animals that can be removed from a stockfor any reason including harvest, live capture or scientific samples. With respect to harvesting,this number includes those animals landed and those struck and lost. This value is equivalent tototal allowable harvest used previously by the Subcommittee, but more accurately denotes thatlanded and lost animals are included. For a management goal of a harvest that results in zeropopulation decline, TAR is calculated by multiplying the current estimated stock size by r (seeFinite rate of increase). To estimate TARs with varying levels of risk the following methodshould be used. Low risk: Lowest estimated stock size (derived from the Mean - 95% ConfidenceInterval) multiplied by r; Medium risk: Mean stock size multiplied by r; High risk: Highestestimated stock size (derived from the Mean + 95% Confidence Interval) multiplied by r. Lowrisk TAR is considered to be unlikely to cause a decline in stock size, whereas a high risk TAR isconsidered to be more likely to cause a decline in stock size.

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Appendix 4. Glossary of terms used in the reports by the AFSAC Fish Subcommittee for1991/92, 1992/93 and recent years. The following definitions have been agreedupon by the AFSAC Fish Subcommittee and apply to the reports by thatSubcommittee contained in this annual report, as well as future reports by thatSubcommittee for AFSAC.

Age at length = 0: See t0 in “von Bertallanfy growth curve”.

Asymptotic length or weight: L4 or W4 . See L4 in “von Bertallanfy growth curve”.

Bimodal distribution: See Distributions.

Brody growth coefficient: See k in “von Bertallanfy growth curve”.

Cohort analysis: This term is also called “Sequential computation of rate of fishing and stocksize”. A “cohort” refers to all fish of the same age which are assumed to be subjected to the sameenvironmental and fishing pressures in a given year or time interval. In a simple sense, cohortanalysis means the interpretation of cohort frequency data and related fishing data collected overa period of time. However, “cohort analysis” usually refers to a number of complexcomputational techniques which estimate “F”, the instantaneous fishing mortality rate, from thefollowing observations or estimates: “Z”, the instantaneous mortality rate, “S”, the annual harvestrate, “A”, the annual mortality rate, “C”, the catch, and “N”, the number of fish in a year-class orsample. The object of such calculations is to determine the fishing pressure that populations canwithstand. See Ricker (1975) and Winters (1988).

Condition factor: The condition factor (cf) is a simple calculation which describes the relative“plumpness” or condition of a fish. It is calculated as cf = (weight in grams)/(length in mm)3 ×100,000. It is an informative statistic for comparing the condition of fish of approximately thesame length. However, since it also tends to increase with fish length and age, it is not the properstatistics when comparing the condition of fish with different lengths.

Culling episodes: Cases in which fish were discarded, and not included in harvest statistics.

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Distributions: Distributions of biological measurements such as age, lengths or weights are mostoften described by the following type of graph, relating the values of the measurements to theirfrequency, or by tables with the same and similar information.

The first frequency distribution depicts a “unimodal” distribution of fish lengths, since it has onlyone peak frequency. The “modal length” is approximately 35 cm, since the largest frequency offish, namely 34 % are between 30 to 40 cm. The second distribution is a “bimodal” one, sincetwo groups of fish can be identified by the two peaks. In this second population, most small fishare three years old, and most large fish are 8 years old. Thus there are two “modal ages” or mostfrequent ages, 3 and 8 years.

Instantaneous mortality rate (Z): Is the negative natural logarithm of the survival rate. It iscalculated as Z=-{loge (Nt+y /Nt)]/y, in which Nt is the number of fish in year t, Nt+y is the numberof fish in year t+y, or after y years, and y is the elapsed number of years. Mortality is expressedin this form because, over a period of years, annual mortality and survivorship are expected to bea fraction of the existing population, not a constant number per year. The instantaneous rate canbe easily expressed as “percent mortality per year” by calculating 100 × (1 - eZ).

Instantaneous rate of natural mortality (M): When natural and fishing mortality operateconcurrently, M is equal to the instantaneous mortality rate, multiplied by the ratio of naturaldeaths to all deaths.

Instantaneous rate of fishing mortality (F): When fishing and natural mortality act concurrently,(F) is equal to the instantaneous mortality rate, multiplied by the ratio of fishing deaths to alldeaths. (F) is also called rate of fishing and instantaneous rate of fishing.

Maximum Sustained Yield: Largest average catch or yield that can continuously be taken from astock under existing environmental conditions.

Modal age: See Distributions.

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Modal length: See Distributions.

Recruitment: Addition of new fish to the population which is vulnerable to a particular kind offishing method. Recruitment occurs by growth of individuals from smaller size categories.

TAC: Total allowable catch or quota is total number of fish or weight of fish which areharvested.

von Bertallanfy growth curve: The most commonly used growth curve in fisheries statistics,which describes the growth of individuals or a group of individuals. To describe the increase inlength, the curve is:

lt = L4 (1 - e-k(t-to))

“e” is the natural base of logarithms or e = 2.71828; lt is the length at time t. Parameters whichare estimated after fitting the curve are:

t0, the theoretical age when the length is zero (1t = 0);

L4, the asymptotic length. As t increases, the predicted length or weight approaches an asymptote;

k, the Brody growth coefficient, or the instantaneous growth rate of the ratio(L4)/(L4 - Lt).

For more details, see von Bertallanfy (1938) and Ricker (1975).

Yield-per-recruit: Yield (catch) of a fishery per number (or unit weight) of recruits entering thefishery.

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