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La -reprodu~:itn, ·~~e,ni0 artie lie~ 'de'· ce ~i;~ilm est . s~umise a Ia' Loi ~nad;e~e ·SUr le droit ,d'a4teur, SRC ·1970, c. C-30. Veuillez -prf!ndre connaissance des formulas d'autorisation·-qui a_ccom~agnent: c~~e these.

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NO~S.L'AVONS RE\ UE. \

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. . . . . . . . . "' ··AGE DETERMINATION :AND BIOLOGICAL 'STUDIES

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OF NORTHERN' .PIKE ESOX LUCIUS liNNAEUS .:1758

.J~ lOBSTIC~ AREA, ~~~LWOOD RESmV:DI~, lABRADOR· . . .. ..

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. . . ~-· ... · © : ·, J.ohil,P: :.Wh•~ler, B.Sc. (HonourS) ·

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A' thesis submitted iA ·partial , fulfillment of !£.e · requirem~nts

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. fo-:· the deg~e of \ . .. . Master of Sclen·ce . ·

DeP.artffie.Jit. of Biology - . · · Menioriaf University ·Of Newfoundland

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·A ·sample o-f 415 n~r-thern pike .was tak.en from· l>elo~i · L~bsti.ck . · ..

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, structure, Smallwoo·a . Reservo-ir-; during the su11111ers of 1977 and 1.97.8.- - . '· . -· .. . ·'

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. ·. - . .. :Four· met~ods u.~ determination, scaie$, _op·erc:ula·, d _eithra an~ ; .' ~ .

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·~· ·atoli.ths, were~ompared -to dettrr_ifine .;.f ~Hfer~nt . met'hod~ provid~d -, ' ,, ·: ' .' . r • ' ' ', \ n • :' I • •,' '

.' '.' Comparable , ages· for . th~ ·S~f!le · fi.sh. )malysis ·Of· COV(l~_iaJlce showed . . ' . . . .

.: si gnifi.cimt differenc~s between empirical .and : ba~k-cal cul a'ted age..: - . . . ' ' ·. . . . ' ' ' .

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length. re_gressions using scales, a·pe~c~la . and· clei thra; _ there w~re ./ • •• J , • I : . . ~.. . . ·. • . , . • . . . . . . . . . . . .

· -- .no diffe·renc·es-us.fng otoli-ths. ·otoliths .were - iJs~d · to study a·ge:·.an(f · . ' . . - . . ' ~ . . . . ' . . ' . .

·.- ·· ···growth:M 'pi~~e- · froni ··L9bstjck_: ·:The maximu'~ age. ~co~ded was -J~ years, .· "' . . . ' . .. . . . . . '

-. ·with 49~ of the· fi'sh in the: -7 and-8 age..;g~oups: · The fish . ra.ns~d in_ · ~ ' ' • . . • . . . . ' ' . • ' ' i . : • ' ~ ,,!'. • ' ' • • • • : • •

.. length from.9.3 ·to' 87.5 em, · w"ith a mean · fork -length-.of 62_.0 em .. The · • • • ' 0

- ' . ' . . ·· .. :·: wei ~ht in~rease~ . a_~· th~ · 3:0634 p·ower ot' the 1 ength ... ·_ Coeffi.c.ient of .

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. condition .values of mature. fish, sampled · from June 'tO -September, ·· . .. • . . . ·I .

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.. ' were highest in e~rly June '_and lowest in late Jtb,e. I Instant~ileou~ - .

tot.al · m~rt.al ·i~y rates.,'c~l·~~lated .. f.ro~ :a ~-at~h -curve,· ~ere hi~her fbr · · · -• ' •, , • . ' ' • ·, . \ i ' ' • ' ', ' ' ,' ' • '

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fem~les. (0. 37) ·th .. an fQr _ nia~es· (0. ·32).: . -The overall · sex _ratio was, · · . ... · · ~ .· . .1-{ . · - .. . .

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. clo.se t~ · l :1 . . t~ales . were. ~predominan·t>ly '(sot)' mature .by ~ age 5, 'or. . . . . : . - ··. . . : . .. ( . . : ' ·_ . . ' - . - . . ., . ._ .' . ~ ' .:

· . · at 40 em,· fenia1es by age •.8, ·or at 60 cni. Observation of :. ovaries of ; ' o • • 'o, ' o • ' ' ' ; ' o o ,; • o , : ' ' • ' • o • ' I ,' ~ ' ,I o o : ' ' • • • •

. . mature ·piRe :indicated tna,t all pike did not spawn each 'year. · F~cundity I . ' • • . : . • • • . . . ' : · ' • . '" . : • • • -. • . -:. . . • . ' • • ·. I : ~

. estimates of · fisn 51 ~0 to · 87- ~5-·cm in length ranged . from 5?J2 to 62,000 · . . . . . . . . , . . . . .. · · t

' .· . . . . . . . , . . ' . I , · ~~; th a mean of 28;016 . .. Of the 86 stomachs examined for ·food contents,

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62% "were· empty . . Whitefish · was t~e principal item {64%) where food > ; • :. : • • . • . • • • • ' - • • • . ....... .. • • : .

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. _,_.: ·. : , · . _ AcK~IOWLEDGEMENTS .· ·_- · .. . _: ..

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·{ _. -:- .; ... The author would like -to ex·pres·s ~iricere 'than.ks· to hi'~.: Supervisor, -· . ·. ·::_·-: ···I .. _.·: .- . - . . . ~: .· .·· ·. . .. ·._ ··, . .. ;·· .·:._; - .. . . ·_/ . _.· .. ' . ~ .. ·. 1

·'1. . ·· \ .. ; ·;~ Dr. _ Jrf4. ~_reen, Biology : .Oepart~rent, · for. he·lp_- a~d g_uidance ·,throughO.IJt:thi_.s :: l1

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The author is very··_ grateful to the Fisheries and MarJ ne Servi<:e, Freshwater : .. · i . .

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: ;\_· .. :;a~d Anadrornous Fi~h )·1anage~ent ~r:~~r.~in,f~r t~eir. financia 1 · a ~d man~p~wer. · ~. . ~ . .

~ I. · _ ._~ -~P~~rt ~roughout·th)_ i~v~sti.ga'tio~ ._.. Speci ~1 ·thank_s ~are·_ : ~~xte~ded. 'to : , _., ,

. . . : \ - .Mr.· W.Jf •. .' Bruce, job\stiperVisor, fo'r ·his' con.str~eti-ve ¢riti-c;ism and encouragement:. ·:· · / • , • ' I I ' ' • • ' ;. ! • ' • ' '" • '' ' ' ' • -' '

·1 · during th'e ._study._ ~he a~thor .. would. also· like to: thank t~chnicians~ · p.·. Down-ton, · ' · · · ':' !I . . .· : . . . . ··: - ,.

-. J ·_.· . .· j, .: Caine; anld D. 'Jaco~s for· _their .~ssi~t~nc~ . i~ : _da .~.a. _co1le'ctio1!! Thanks ·are ·.

I : .-.. : l. ·.: . :a,.so: ~xtended tQ 'or; · -~. K. · Misr:a,- H. lear and. fi: Tucker · for~ their . as.sistanc,:! .. ·. r .-- _ . . . .. · . ---'. :. : . ·. · . : . , · . . · . . .. ·_ . ... - ~--- -. c: ··-: ··:· :/

... i ~; th ,'st~tis.ti_ ~~ l,a~ci'l~s_es an~ ~-o~pute~ p~gra_~fn_g _ •. : :~ - : .. ~ ·. ·:·· _._-· . • .. _ . . (. ~ i The. author also acknowledges the ass~stance of the Churchill Falls Labrador ·. · I·. . . .. . . . -~ . . . -. ·. . .. . . . . . . . . . . . . . : . . -~ . -:. . . '

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.. ·,j:- . .-, ·.-- Corpo:-ation·, in·· particul}r __ ~· · Nuss and S .. Lew_is ' fo_r provid~ n~ water .flow :,da~ .

> oj; -and It Bar~~·s_ for assisting in data _collectio-n. · · 1

. . i . . . . - d . . .· • • . . . . . .

j .. "' Thcinks· are also - ~,.x_tended to or·. ____ D; .La_rson:·:. s;olo_9!-· ~p_ar_t~~t~- - ~o: .

"t- ·:·· ·critically reading the the~i -~ and his -valu~b 1 e conments. im:_~ sug~es ~ions . .. . . . . .I • ' ' ' ·. . .. ( . . - , . -~, . .

· Fi nal)ci a 1 s uppor.t \'tas provided in the form of a _Pro vi nci'a 1 Goyernme·F) t · · ·

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. ' Fellowship :and a University FellO\'ISh.i p which are g~eatly a~kno~l~~ged. . · ... ·. . . . ·... . ",' . -;· .... ' . . . .' i'-' ..... : . : . . . . . "'· . ' . • ,, .

'· Finally, the. author wtshes to thank. Mrs._ M. _ ~nes for ~the ty'ping·of this . . . - . .. ' ·. . .

/ . ~ manuscript.· .. . ' : ·

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• ' . ··. . · . · · .· ACKN9_WL.EOGEMENT~ . ~ · . . .

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• · · • . 'LIST OF TABLES . ' ·,~ • ' • • I " . ·.

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·; 'liST OF FIGl,IRES ,. ,· . .' .. · .• --<. • . ,"-

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· INTRODl!CTI,ON · · ,.. . ·. .·. ··.. •, . . . : . . . ; . · .. ~ES¢r_t_I PT){lN OF $,TUDY .. AREA . . . · .. ::-_ .. ·

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· . ! - .. . MATERIALS AND METHODS · ': ·

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. : -!· ·. · .. . :· -. • .. r. Age dete~1n_ation . . .. ' . , •.

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, ( . I : • ,. • ' . ! . ,'· -.. -· •' . . . / ' . . ~ - · ·. · -~ .. ·.· ·IL __ Biological · stud.ies:· · . .. .. · :·:· · ·.

. · _: -L :.-. ·• _.. , . . -- ~ . J.\; s_i ze · a~~ .a~~ ·ao~pos; tion :. _. . :. : _· . . :· . . . · : . 18.' .

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l . _. ·. · ,:2 We·1gh_~_ · · ·. :-. ' • ---, · . · . .. -. _

. · _ : .. ·. .- .. . d·. , 3) Agf! > __ . _ . . · ,> · .. ·· . . .• • -1 I ' . <l · ·: . · · ·:·:. -- '. :- ·s·. ·GrowtH-. · · · ·. . ·

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'4.1 . . ' . ' -. : . >--~ . ' . . . . • . ' ' .. · \. .· · · · · . ·. · · _. .. l f L~ngth :..we1ght · rela~jons:hip ' · . -.

-; · · · ' 2') · Length "111stribution;:of-age- roups -. .. ·. "-. \·· ·; · · · · · . 3) Weight distributi.bn of age- .roups

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· 4).- Coefficient 9f ·con'di.tion : . . :. '·. 5 r Marta l i :t;y and 's u rv' val ' :

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. c·. ~ Reproductive bi.olo.gy_ . . _-/ ,. · . . . . . ..

.-.:, .' 1~ Sex ratios . . :- · -2 Age an~ length .at f1~s ~ ~aturi ty

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D . . Food habits 4 •• ' .. • • • • ' \' : ...

. ' . : DIS_CUSSION. --·. . ·.

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Table

. . . 1

- v -. ~ .

._,

"' .. . · LIST. OF TABLES · ·

' I 'o

·I :\-' . ,' I ' o > \ >

.Relat~on betw'een· fork lengt, of fish (em) and -magni.fied (<:m.-x 22)' ·s~a·le l'ength of northern · pike .from Lollstick,· Labrador. · · .· . : .. . '

· ·2 · . Re>lation between .fork .length of fish (ern) and '· magnified (em x 6.67). opereulam length (if· · ·

northern pike from LobstiCk,. labrador. . l . • ' .

· · 3 Relation b~.t~een fo.rk length of 'fish (em) aiid·.magnified _.(em x 6_.67) cleithrum l~ngth.: of . northern pik.e from Lobstick·, Labr~Idor..'

, .' , ' I • - ' >

.·.ReJation b~tween . fo.r~_ len·gth of _fish(em) . and· - . . · :_!!!agnified (em x··30} otolith length of n·orthern · · ~ .

4 "

· . . _ __. .......... _pike _from .Lobstick, Labrador. · . . •;-/ \ r • • • ' . • .

.. 5,. .. . Jogaritnmi c and exponent.i a f forms . of the . · __ · · regression equations· for _ the relationship . -between--fish .for_k l~_ngth (L) and elength _of the ·agirrg struct'ure (S);: using ·scales·, opercula, clei~hra·, and otoliths~, - of ~.orthern pi_ke fro"'m...,) Lobstick, Labrador. ·- · ·. • _}.

6 Empiri~al - and back~calcula.ted average fork -· lengths . (em), using scales; ofth~ different. · ~­

, · . · age-·groups of ·northern .piRe ftom lobstick, ·.: ·

/ 7.

8 -

9

·'

I ·

. . ·

' >!)

· · · LabPador. -: · · · r., :

...

Empirical and back-calculated avera._ge fork • -1.1engths (em); using opercula, _of. the different

·_ ag~:.groups of ·northern. pike· from Lobstick •. ~abr~dor. . : · · • . · · · . · ·

. ' , - ... . - /

. Empi ri c'a (and back.:.:ca lc'ul a ted avffft~ge- fork . .- · ·1 engths (em}, us i rig ~ c 1 ei th r:a, ofthe ·differ!!nt age-groups of no'rthe m pike (from lobstick • . Labrador. · . · i. • · · . ' . .

' .

Einpi\t:ical aAd back- calculate-d ave'rage fork : ·, lengtlis ·(c!f!), using .otoliths, of the different· age-groups of northern pike from Lobstick, ; · Labrador:

.. , '

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'· . ... ~·-~- -··- . ... .

. _I

I .

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Page· ·

-1'9:

: 25 . ' ' ' •'

. ··27

28 /

, ,

'30

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32

34

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. Table ·

10·

. 11

... . 12

13

14

. .. '

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..

· - vi - . ·

. ·.

. . . I .

:bsummary of. results· of ,,covariaric~ analyses for · empjric~l arid.t back_-~_l_cti1ated ·age .. lerigth · .,

regress 1 ons, rna 1 es vs .· femql~s il . of northern ·. .. pike· from Lobs t,i c~, ta~ radbr~ ~: ~~. .. . . _. ·· ·

·-~ Summary of results of .covarial.e. _analyses for age-length· regressions (~exes·. separated·

' and combined), empitical .vs,_~· back..:calculcited · of northern pike . from Lobs tt'ck, · Labrador. ·

. . . . I ' I . I • . otto • .'1 . . . : . • . '

Summary o·f results ·.of cova.~iance ·analyses;for ·empirical arrd . ba~k-~alcul:ated age-length- . regression~ . (sexes separated and combined)~ · -:

.scales, vs •. operculaj vs • ./cle.ithra· 'vs . • otol.i,ths ·~ . of. northern pike 'from Lobstick,-. Labrador. . ·

' .I. I I

I I I

I \ I

\ \

, I

. .

. \um~~Y .of• re.sul ~s'. p~· ,'~ovar~an~e· a:n~lyse·s · for back,.calculated~_ageil~ngth regressions (sexe.sl

·separated and combined), otoliths ,vs. · scales, . . otol.iths vs. cleith;r~, oternhs vs .. opercuH1~ · ·' . seal es v~. OP,erc_ul a:; ,seal es vs • . cl E!ithra, an ·

. opercula vs. :cleit~ra of northern pike from , · lobsti'ck, labrador.i ·': ' · . . . . . . ; ·

. . ' ! . •

Page ·_

-. '36

:

••

"37

' ·

'

.. . 38

.·• 39

. . ' . /

lEmgth distributiori·· of' northP.rn. pike from · · · ,40 · Lobsti~k - for se~es j~·ombined and _~exes -__ s~parated~, . ./ · ·

15 . · · . . Wei -~ht .diS t~i i>titi 0~ Of ·nO ~th~rn ~i.ke . . from . ;·I . 43 · Lobstick fo~ "s~xes~ ;combined .and se~e~ . sep_ar~~e~_· . · . . ·

Age composi.tion·ot ''n.orthetn pike from Lobstick · 16 .

1.7

18 .·

19

. for sexes -combi.ned- ~and 'sexes . separated. . 44 · ••

45 · Loga.ri ~hmi c. ·arid exp!pnen.ti a.l regressi-on ,equ.at·i~ns . . for the relationship between fork length .(L em)

· and whole weight (Wl' kg) ·of northern pike from ·. · Lobstick, Labrador. · · · · · ·

· Empirica~ ~md -~al .~~ ee1 · a:ver~~e \'/hole . weigh~s-. . . 45 . . · (kg) ~of the differe t fori< length· (em) interva.ls .· of . northern 'pike from Lobstick, · Lab~ador f . . . ' .. : I I . ' .

·· Comparjson o(the c~icul .ated fork len.gths ((:m) of . .. 4l

' . ...

·. the diferent ag~- groups ' ' sexes combined, of ·. nqrthe • pike from four -areas of Labrador.

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Empi rica 1: and c~l cul a ted .a v£{~age ·weights · o·f . . ··.1

the different age-groups _of norther:n pik~ · .. ' • .

/ 20

from · Lobstick, Labrador. . ._ - - · . . - ... . .; -~ ' ·. -'\ . 1-

Change ~ coef.ficien~f · 'c<?~dition~ . from , June to September 1978,- ,of mature northern,.,.· 1

- ·_, ... \ ·. pike •. stomachs , e~pt.Y. a.t ti~·· of captl!r.e~ ~ 1fn)' orTI' . · \ Lobst1ck, .. Labr~dor. · ·. . . 1 _ ~t~J:_ . i

. 2~. -. -: Se~ · ratios .of. northern pike• by age-·grciup, . ... . . '- _ from Lobst1ck-, .Labrador. . ._ ....._.. · . ;

\ . .. t· . . . . . I

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55 . ' ' ' · .

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i .. · 23 ·. Percentages_.; o.f rna ture nort~ern ·p; ke; by -age / • .. cla!is ' ·· from Lobstick, Labrador. . ·

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, . Percentages of mature northern· p1 ke ~ by I

length - class~ from Lobstick, Labrador. · - •' ,. . · . The·.· ~e11~tionship between t~e· .n~mber ~f ~mat~·re · ~ · . eggs · (greater than . 1..0 nm. in di.ame.ter) per .. · . - female· and :fork length (em) . for '49 northern · pi~e . from L~bstick, 'Labrador. .. ,

' Th~ re.lationship 'betWeen the numbe·r.of ·mature. ' . eggs· {greater than l .. O.rrm tn diameter) per:: ·. female ~~d weig~t (kg) · for 49. northE!rn pike . <from Lobstick, Labrador . . · - . . '. . .,

. . . . . ' . ,. "' . a . . . -

· .The ·relationship between 'the nuriber of. mature eggs (greater than l.O .rim in diameter) ·per .· fema 1 e · cmd age· .(y~ars· ). .fot- 49 northern pike

' ' .

~ Jrom L~b~~ick, ·Lab:a~'ir· · · " ,

Percentage. occurrence ·of food · i terns in stomachs · \: . with food present from pike of various 'sizes . frqm lpbstrck• Labrador.

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. .. ·. · 1 llST OF FiG.URES . .. ' \

-; .' • I . iii .

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Locati.on .map of ·smallwood R~se-rvoi r . and . ~· •• !'

' . . - ' _~,.:·<-\.~. .. ~obs}~ C.~ ·1 tr~c tu~e: · . _. · · ·.. : .. . ·' . · . · . . '•

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·,, 2 ; lobst1._ck structure, .Smill'lwood Reservoir.

'· . . ·. . . . . . r·. . . . - . . . . . . Fyke·: net j,"" flooded. ba.ckwater _bel o~rlGbsti ck · '• . ' J . .

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· s -tructure~' · · · - · . · · ·. · ' I , •' t • ·, \ • '

4 · .' · .. : l~b~-ti ck .,s;urface .. wa~Efr. temp~rature· (C) :from-. June· to September.1978. . · . . . . ·. · . .· . . I . . . . / .·.· .. ·

· 5 - ·. Average ~aily ~ater. f ,1 O'f! '(M3/~ec) through · · lo.bstick ~tructure from · May -to S'eptember 1978. ·

' ~ tl I ' ' • ' ' ' ' ' • , ' ', : ' ' ' ' ,' ' I

.. Empirical . (sea tter p·l ot·s an·d . rahg.es.) and. . · · ·. c·alcuh~d {fftted;curves) body ·length-scal.e

. <' . 0 . ' I ·,

' . _. . :· · · length r:-el~tfonship~ of northern pike .from · ~obstick, L~brajlor. ... . . ~ - .:. _ _ :· . . : . ':

. , ,, . 7 • o • I . . .

·. ·.

. . :.. 9. 9

· · :· lo ·, 1 .

1·1 · •. .. ·

~mpir.iCa_l .:,(scatter pl~ts arid. -~a.n~es)_:_artd~ . calcula._fed {fi tte~ curves) bo~-etJ9th-~penculum . 1 ength -rel.ationshlpS .Q.:t.nOrtfle-rn · P.l.ke 'from · ' .Lobstick, Lab ra o~ .. · .

. /'

jr{lcal {scatte'r plots and ·ranges) an'd' ·calculated (fitted curves) body ·length~cJei thrum length relati on.ships· ·of: northern· pike ·from · Lobstick, Labrador: . · . · ;, · . ;: . .. . . . . . ' .

" . Empi-rical (scatter 'plots and ranges} · and . . . c~l culated ·(fi ttefcurv~);o,dy ' le~g~h-otol i th.

: length relationsh1ps O'f .northern . p1ke from · Lobsti~k, Labradqr. · .· . .. ,. · ·· · ·,. . /.

· .. Empirica_l · {sca:tter plqts a~d ranges) and back- · _: ca.lcula ted· {fitted ·turves) . average ·1 engths ·(em),' . using ~ca-les, of the different age-.. groups of · -~· · northern· pike fr.:om ;Lobstick, L,abrador. ·. ·1

. . . :' .\ . . ·· .. : ·. . . . ·_ ·. . . . .

.11 ' .. ·· · . Empirical (;;catter. plots ·and· ranges -) and· back- . calculated . {fitted curves) average 1 engths . '(em), using o'perc'u1 a, of the different age- gro'ups .

·of northern . pike from lobs'ti ck, lab radar • .. · ·. · • • • • Clo • • • -. •

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. ~ . . - . ' . . ·. ·, .. . 1'2 . \ -E~pi·rical · (scatte~ pJots ~ and ·.ranges)_ '~~c(bac~~ ·

__ ... .. : calculated (fitted curves) , average lengths (em),.-,­-· using . ~h~ithr~ -. _- of the · dif.f'~rent age~gr-oup_s _: ~-~ . of _no~them pi-ke from Lobs.t1ck, ~a~r~dor. · ' · .·

" . . . . ' .

, . . ' i· . ··.···

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33 .. - ·- .· ..

<-u-. ' '·

1.3 · Empirical (scatter:-.: piots and ranges.} . anc(b~ck- . . ---cal.c..uJ:ate-d--(..f.i-tte&-cur~es ) · -average _ lengttls~ .(cm) ~

-_ using otol} ths •. of the d~-fferent a~e-g[.o'ups ~f

: . . 35

· y

. ··r

_·14 .

. - northern PJ ke -from Lobstl ck, Labr.ad~r. - . · ' . . . . .· ' ·: . . ·. . : . . ' . . '· . . ' · ..

Length-wei gh't relations~; p -, sexes separated~----­.. · i>f_ northern· pike from Lobs .tick, : laprador • . ·

·! · ·· · ·- · 15 .- .· E~ -i~ical . (~cat~er·--~lofs ~~~ -r~n~e~) a:~ ·d :-<- ~ .. ' · . . i. . ~ : .. . : ca leu la ted {fitted curves·) ·.average wef gh ts . (kg'). . ~\ _··- ·. · ·- · · . -of the -diffet7ent age;..groups of .northern pike · ·

. I - · -from Lobsti·ck,· Labrador. · _·.: _ :..- ·. · . .· ~ .. ·

49 . · .. :

.. ',\

. ' .. . , .

.. ;

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. ~. _.:: .. : · 16: Cnang~ .i·n· c~ef~i ~~-i oi .cond~ti ~-n·:: ·.~rom : ·~u~e .. ~o .. . ·._, ·· · · .. ·. _ ; September.1978, :of mature northern p1ke, sexes I

.. ·combined, stomachs empty ·at' 'tim~ of capture, .·

'52 :· . k ·:·-_ ·

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. ·from lobstick, .Labradar.·: · · · · · · -. • • ~ • • • ' • • ' • ••• • f .' •

· __ .. A _plof i.of.~unt~r ~-f - fish· ca~ght (na-tural . _ logarithm scale) and -age (arithmetic scale), ~­' . used to e'stimate the fnstantane'ous .total . - · , . .

_ - mortality-rate -of northern · p'ike from . La~stick; · la~rador .. : ·. < · .- ~ · _· i

18 ·_ . The - r~lations.hip. b ·etw~en: fork·leng.th . (em) _.and e'gg . 58 . -·. numb7r in. nort~ern :pike from L?bsti-ck, labrador.: 'I "

. ' . . • b . '

19', ·tne t:"elatio~sh'ip .'hetw~~n whole ,weight{kg) ·an'd egg ·/ . -59 · w: n~n'ber _i:n northern pike from· Lobstick, ~abrador. · ·

20 - ~~-~- The .reia~ionship between. a~e (~~ars· ) and egg number . . . 62 • . f,, '1, in northern _pike ,,from lobstick, labrador. . . ·_

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-" - ·~ ' ~ ' Hed~,r~_trom ~e~OWJized the_ diffi"C.!.!l~~ in aging no~thern .pike; he suggest~d :.: ,"if . ..,:(' ' .... " ..... . • .· • ' -· ... ! ~ ,'· · .. ~ ~t • .. • ~· ... ·· . .. .... ' . ·_' . ..

~{ · ..:~· .· ·:.··.·. , th~t· a f1,s~cou~<t be _a_ged by 1_ts. ~e~~eb?-"~1'~ j\ngs s1~1la:r to .a_ ~re~ b~ittg aged

.. ·.~'}:~ :· _ b/it~· gro~th rin,9s. -Var,iations·. of th';'s t&'hnicfue have ~~en used te· age .· .. · "'· ,;a~~- , ' • • • . ~· • I , - ' ' •·

· -.:·-~ : ·. · ·· ), nortttern·_ pike · f~r the .. Pa~t ·· 220;-ye~r-S·: .. . si~~/ .ann~lar ~r.Owth zones _Wftre .first • ... . . ' . ' ...-;: } ' .

' ~etected 'on ' pi_k~'".c;~~e~. by 'Hof~~4~~ __ (190~·), ·:~ey\~h~v~ b~n. · use-~ ext~ns.ively 0

in-age a,nd grow asses·s~rents H1i11e·r. and Kenm!dy \, l948;rWilli'ams 1955'; -Frost • • ~ ' ., • • - • • , • ':f ... <> ' • :l .. ... • • . 1 . , ,. · ·.l·apd ·Kipling 1959; -Ca~,selrnan . ._19()7_)'. ·~everal_ hard t'issues· have ~lso b~e~ uset

X .., .. I , .._ ,' V • .~ • , , ' • . 'l.l~,.U , 1

·. "- i .. -'·· . · . >o.petlcuJ~ (Svetovidov. 1929; Frost a"'n·d Kipling -1959)) teeth ··(Ast!tnin -1947), . fin '·, . ~ . . . . . ·~ ... . •. ' - .

' · .:.; · .· .: .. . rays:· (doh~s·on 1959)',....o_tolith~ (Hatfie.ld et:· al. 1972) -arid ci-~ithr.a (Casselman·. • • I I • . • • . . •• , I.:-'·; . . . . . . ... . . • . ~ . .

··~:-,- ~·- . · ;. i-~p~ep~r~~-on) ·: .'\ ~-, .. · . ; ~ ·- ~ ~ • ..

, .... . •

.. \· .

-.. ~ -~·-. ·" : ·.> ··. _: ./ T·h~ - ~~a.r~~nt'-'of Ffshar-ies. and O'cea·n·~ has cond~~t~d ·:several fish studies.

--~- • • • .

1

, • !_ bf,na~4·ral~ lak~s -· , an.d t~e · s~a1 )woo~ . ~e·~.~Fi~i :r i ~;-~est~ . labrad~r.. T~ese . . -_ .L , .. ~. i ~:. _ . i.nve~~·igati-~ns·· .. of Ja;o~ie . L~k~ · (Br,uce 197~}, L~bst1ck : a.nd 'saodg.irt l~kes · ·;

~ ~ (~r~~e 1975); Ten · ~n~ . La~e -.CPa~on~·19:75_)~·and · ~·s~okma-nu~~ Red'er,v~ir {Bru~e · .. ~. - ~and P~r~o~s ~979{ have deal~,~~ - ~art:·.~-i -th th·~. : ~-iolo·~ of north~·rn. ~ik~·~' . ~ .. - .. . . . .. .. . ' . . \ . . .·''· . .

<· ·. , . -:, .. · In the_ sunme~ •. ofb_l97,7 and 1978, :a rrored~ta<ilec;f bi_ol __ og1ca1 ~tudy wa_s

~ . ~- l!~ -. : ~

. 1 ' . . . .... . . ' ' ·, . ~ . ' ' . . . . ~ . . · ~ ~ conducted ·on ;northern pik~ froin . wat~:s below!, lob's tick structur~ a release

Ji . •, . . ' . ·, . ,_ . . . . .

g~te :for the .-sm~ll~o~d Reservoir. ·· The ·-if~a was ·· chose~ because of its

' · .. · , ,acd~s• i U.nty an: the, knO:.n pf.es;nt~ .of •a 1a rge ~ ~ ti on 0 f no rther'n Pike . . J ·. · . ·· ...--' The stiuty .Was d~signoid to cdmPare fotir' methOds : Of age .detenriinatiOn; •

·· l , 1: · .s·cal;~.; opercula·, cleith;~ an~. o~tolith~ .. -;J.'The C:~ffip.ari!ion~ ~e~e maje to.-.· \ [ · · _. , · · dete,·~.ine1: i_f __ di~;~~n~ .,rtetho_ ~s · ~ -~-·'i~d~~-. _.· ._· .. a'ble ~g~s f_or the saine fish.

·,J· •,l· Tlie phehoo;<;non · of .differe~ t ages for' fish.' aged by. S ca 1 e_s ~nd : ope ~cu11 a has,

.. \ j :_·. been ~~su~rited (Leer~~ ·19~~; F~d. Kipli~g ~ .9s9; H~~s~n ·1978). Aging ~ . . . . > . . . ··. . ... . ._;· ·. c :? :. . . ~ .. . ', . . . . ..

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s tudi ~-~ \of another. es~~i d,

. 9+ ye_a rs could ~of b~,' aged

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. ' I ' .. . the_!llusJ<ell un~e, have shown that . fish older tha·n

. / . . . fro"l scales, but cleithra were useful for.fis~ as . \ .

old as 16+ years (Har:rison and' Hadley 197~). The preV.:J~ous; tJSe ot' oto)lths . ' ' ' IJ I ' ' ' o '

~ · ···-· . for· a~ determi·natjon of pike has been fimited· (Hatfiel1f- et al ~ 1972); they . .

h-ave ~een usedextensivelY to age other freshwater and marine· species, reviews ' . ( . 'r,.

,I I

. . ' . . ' .· · r;~ • . · . ;.---_ . ,i)r _p

of .w~·ic,h have .been _presented .by' .Graham ·(l929)', ·Trout (1956} and 'Chugunova (1959) • . . . ~ - .. I • · '

Differences have also been -shown between ages derived from -scales ane otolith~

· :of other northern freshwa'ter fish. For e~~ple~ Dubois a~d Lagueux (19~8)

found that: for ·lake trout,· such differenc-es, i .ncre~sed wi.th. old;r .fish.

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Simi ~larly~ for_ i~rgemout~ bass, :Ma~ald~_ · and MacCrimmo~ o9i~)-. found .thatage"s .- :0

_-greater ~han 7 ,yea_rs assigned.:f .rorri scale~ wer~ .more. lik~iy to uhde_res't~mat~ tr~e a·g.es . than th~s~·· assi-gne~ - ~~om oto"l:iths . . such agi~g dis~;epa~cies produce :

. . I . . . • -

diffe.rent _ estimate~ of growth, mortality, · age at. maturity and. ~bundance of year~

·' ' l

' . '

classes, whfch -complicate .s to.ck assessment and managemef.lt-'deci's ions.-

Di fferenc.es betwe~;~ . the ·g-~owth . rates· genera ~d· by 1 each. of the . four aging . . : . . , . . . ' . : . ... ··~ . . ,;.. . ' ' . '• '

. •methods ·were · analyzed to-try to . deternlin.e if the results · of any one method were ~ . '. ,. • I ' ' • ' ' , ~ ' ~ ""':' i \ ' , ( ' • ' ' ' ' ;t '

, .

~~re- rei iable .tha~ a·nath~~· · . G~ow~~ --~asuremen,ts obtaine·d 'from fle~gi n~. ~ethod • ~ • : ' • • ' ·. ' • • • • • ~ ' • • • : • • • • \ • <:> ' •

ll)_ay. be precise if'visi.ble annuli : are ·eas.ily ' delineated; however, ' those. meastiremenl s . ' .·. . ' . . . . . .

may not be -biologically meaningful if f;or ~orne reaso~ one or more annuli are . .~ ..

· obscured and are·_ not counted in agi'ng the · fish. Even if .tfle 'annuli.' ar.e··

easily delineated., it must ~e . <!et.errrii ned .. that they are yearly and not fals_e p

-. checks caused by a cessation of grow.th during ·spawning_ er advers~ . envh·oryniental

conditions.1

Empj,rical .and back- calculated growth rat es should . not dfffer . . . ' . . . . • t. • . ' . • - . '

, . . signifi~an.tly 'assu~fng that the aging. structure acc'urat~ly reflec'ts. th'e growth .. . . '• ' .

·._· . o( the fish a~d that no a~ing -.~rrors ha~e b·een made. lee's phenomenon, a de_crease .

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in the lengths of younger ·fish ~aH:ulated froin succes~ively older ·age-groups··, 'J . . . ·, ff.

' ' , . . could produce differences between empirrical ·and back..;ca'lculated growth rates.

' ' . .. ' . ' . . . . '

It has been doculiiehted -for pike sampled by ·gi'llnet (Wolfert ·-and Miller: '1978}; . . . . . \ - , ' . . . ~ . . .

.. howe:Ver, Mi.ll~r af# Kenneqy (194.8> · suggest· that for pike·, 'Lee's .. ph~nollEnon '-1 • • •

: is pr:-ob~bly 'an . artef~ct - in.troduced by inaccur~):e ~thods of 'grow~h"-"-~~mput~tion. ~

· · The aging method . which showe,d the least -variation between ·e:mpir.ical and.·back-. ' . l ' . . . • ' . .

. ~ .·calculated g'rowth ..... rates was used' in investi g'ations 'of the size and aie · .... ' . . . I . . , · '

' I < . I .

· .~ .structur.e, growth .ra·tes, · and reproductive ·~iology of\ pike · -fr~m the .Lobstick . . . ' . . •' ·. . . . . ' '.

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DESCRIPTION OF STUDY AREA

' / '\

: ," The development of,:t:he upper Churchi.il River hydroel~ctric J • . . . ~

:potential has created a single -large water system over much· of the / . ' .- \ . ' . . .. . ' . -

,- Lab~ador. _. phteau -('fig. 1}.· 'lobstick -structure (53°52 1 N-, 65~0l'W) ' \ . I , . . . . ' . .·. ,' ; . . . . .

• · (Fig. 2), approximately 90 kril northwest ~f .the town of Chur~ill

F~~l -s, ' releas~s water fr~ t~e -5700 km~ Smallwoo~ R·ese~voi/. .From

· Lob'stick;;the water flows· southeast, approximately 6o' kni, to

Jacop.ie lake where· it is reta'ined in~o · foreb~ys before .entering . . . . . : > I · .. ·. the powerhouse at Churchill Falls.· . · • - ' •• • • <• ~ •

· ....... • • • • \.. 0

Be 1 ow Lobs ti'cl(, the ·sys tern fo 11 ows a natura 1 ri',er channe 1 , . -.. .

wi denin'g approximately 2 km belo~ the ' st~ucture into slow-movi-ng . . . . . . .. . ..

. '

areas wi-th n_umerou·s backw.at~rs and bays (Fig. 3) .. ·The rivfir. ri~rrows -

0 /'

. a~~i-n ap?roxi~ate.ly ' ~2 . km downst~eam. ~11 ~amples were. taken -f~oni the area in-mediately below the .structure to approxim~tely 16-k,m .

. downriver. .. Surfa~e water temperature ·below Lobst-i.ck structure {f'ig. 4), . .

.• . . r 'during the summer of 1978,· increased froni 2 c 1n June to 15 c in

A:· July·, and · dropp~d to ·a ·c by 'septemb~r. ·

... - )h~ · dail,X water flow through _Lobstick structure' durin~· the • ' ' ,, I • ' · , • • ,• . ' ~ • •

sunmer of l978 ranged _from 550 to· 3l30 f.i3/sec. Water. level I • ' • .

fluctuations · up :to'l.5 _f!!, observed in the system.below- (obstick - - - - -- ·- ----- - - . ~ . ' . ' .. . . . :. . ' . .

structure, were due to the variable ·rates ·of \'later -flow ·through I . . _ . ~ . .

the structure (Fig. ,5). Entire backwaters and bays were flooded -. · · . . I -~ . '. '. ~ · ..

1,1 '

· ?r drained wi'thin a few hours - .~ue· to t.he rapid wa~er level-//

f.l uCtuati ons .

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-~-- .... ~ ·-- .. · t ···:·;··~--~-..---:~----- ~-~ --.. -...... -..... - ( ..... _-·-·- ,--... ·-·--: ·· ~ - - . cl) ..

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· .. •. \

. - 6 -'•, .. .-..

., . . "- '

· .. -. . · . / . · A heavy gr:owth of deciduous bush~s· .e.xtends ·tp the ~iater•s ·· . ·

( . . edge throughout ' much of' the studY area; combinations of marsh and · . . ' . ~ . . . ·· .. ' . . .. _. . .. . . . .· - . '

low bushes are found along some backwaters. At times ·of high • ' I

~ . ; · < ' • • - , • • , _I

~ter, these · areas are inu·ndated and. small ponds and bogs are I

I : . . . united with the main system . .

·' · The bedrock of the area · consists . of archaean gr~ni tes .a.nd

' . I .

gneisses 'dating back to the' Cainb_rian era (Po~ell 197-1 L Limnological

· . studi~s of the are.a' (Duthie·. and o'~tr~f~ky- - 1974) sugges ~ that the. . ' .

': . . bedrock·, which is poor in nu·trients ·and · slow ·to 'weather, ·is

• I, , , • • , , ' I . , , '

·ill)portant in determining ' the water .chemistry, of the system. . : . . . . . ' ' . ... The fish faunQ. of the area· consi?ts of at least ten species:

•.

9 ' .. Large concentrations of lake 'whitefi'sh (Coregonus clupeaformis) are . .

/.

· present iinrredi ately bel ow Lobstick stru~ture : _Qther species present. . ' •' . . ' . ?'

. t• .

. . .·- .

i~clude: nqrthern pike (Esox lucius), l~ngnos~ suck~rs · cca.to~tomus ' . '

catostomus),. white suckers .(f.. · commerson·n "'. lake trou;t (SalVelinus ,·' '

· n'amaycustii,. broo~ . trout (~. ·fontinalis), lan,dlocked salmon (Sal.nio · ' .1 ' : , ,1 . '

salar)~ _burbot ~(Lota. lota),, r~und whJ_ ~eJis~ (Prosopium cyl i ndf.aceum},

and ·lake ·chub ·(couesius plumbeus) .. ' .

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LOCATION--· MAP

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Fig. 2. Lobstick structure, Smallwood Reservoir.

Fig. 3. Fyke net in flooded backwater belo~tJ the lobstick structure.

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f'lg . 5, Average dally wa te r; flow 5eptelltler ,' 1978.

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,. · MATEk'IALS AND ~1ETHODS '1: .. . ·:· I

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i .. I • . . .. . Sev~ral . methods w'ere us~q_,-to collect pi~e: - angling~ fyke nets, \

.. I . ' . . I gi_l.lnet, sein~ an~ pl~xiglas~ traps:. The fyke nets, or live traps, '(·

were constru.cted of 1. 9 ern s'.tretched mesh ~nit ted nylon. They, . . : . ~ . . . . . I . . . ·. . . . . . . . . consisted of _'a 30.5 -~ .le_a~er,\ t\'10 '9.1 m wings, a·. body of -one ·. l.2 m

frame, on'e ,0.9~ f~ame, three\ 6.·6' ~ fr~rres and a trailing cod ~nd •.

. , ' }he. leader ·a~d wingswer~ 1.8·~- ·in .deep .... · ~he gil.lnet, with. 7:6 em . · .... ~ . . . . . . .i) .. ' . ·l . . . . : . { . . . -~·-. . .

• .. ~tre;ch_ed JnC?_nof~l~ment nylon ~esh, .was _ 45:5 m ~ong ~nd L _8 m deep·.

The sei'ne, constr~cted of L5 \em stretch~d mesh . knitted nylon, ·was· · ! • . ' •• •· • • '

. . ·. . . . .· \ . . . . ' . . : 3G.5. m long and· 3.0 m deep \'lith a central bag-like extension .of .

• ·. , ' I ' ' Ill ·, .' • ' ' \ , •' ' I : ' ' ' ' ' •

4.b m. · The_'pl.exiglass _tr,aps~ ~imilar in design to the 'fy~~ nets, . .. . . . ·: . ·· ' . . . \ . . . .

· were constructed of 6 .mm commercial grade 'plexiglass ·(Casselman . . . . . , . . • . . I. . . . . . .

. and·.Har.vey 1973). They · consi-sted of a. 1.5 m stretched mesh knitted : . . . . .. ··. I . . I . •. : . . ·• • . _ . • ••

nylon. leader, tv1o 0.8 m plexigl~ss ~lings and a .tw.o compartment .

. \. plexi~lass · ~fap bo~, \neasurin~ 0.9. ~·lo.ng; 0.4 .m wide a.nd 0.4 . m ' . . . ' • ..

\" . ·., . J

A sampl~ o·f 415.pike was cblle.ct~d • .' Diie .to the restricted . . ' . ! ' . . .

• .. • • - ~ ' ' • ! '

· field season inLabrador., samples \'lere collec~e~ from . ~y through·

September. Most of the sqmples \'Jere t 'ak_en in June, prior to and . ' ' \ : • ' • ' ' ~ • I

!fter the .pike had spawned. A -su.bsample ~f· 213"of th~ 41~ pike

was selected for age .determination s·tudies. · This ·subsample· . ' , .

··· ··.ir:tcluded .alJ Of the, Smaller· fish (Q-55 em) ~ollected and -a . I . . I . . . . . . . . . . . . . . , -· ·repre-sentative sa!llple of the .large length . classes {56-9o ,cm) .. / The

: su~sample facilitated· faster a~alysis of age and grol'lth 1,1sing each

of. the four · aging . structures •. . ... · .

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Scales were remoyed fro111 the .ri gti_t side of ea~h _fish ju~./ . ·

below t~e d·orsat fin · arid above · the lateral 1 i~~- The · sagjftae, ·

the largest of. the' three· pa.irs o~ · -otoli~hs. _were-· i.fmov:d. after

maki rig·. a mi d-:-sagittal cJt. through the skull. ,The opercu1 urn and· .

cle~thrum~ere removed 1from th~ right side 'of·thebodyanQ_were ~.- ·· ·.

. inmedi ate-ly cleaned;using a s·cafpef ·and_ water. . . . Sca·J es, .oto 1 j ths,

cle.ithra- -and opercula · .·he+tceforth called "aging structu.res": . ... u .

were ~ach pla_ced between paper and-stored jn an ·~nvel'ope.

Fork .1 ength,.' the d·istance from ·t:he most anterior ex.tremity . . . . . . . . . : . ...

. to · the not~h in th~ ·caudal fin, and total lengt~; 'the distanc~ from­

the ll)OSfanterior extre~ity to the tip of -the caudal fin, ·Were . , ·

measured to the .nearest 0;1 em . . · A conversion factor was calculated I' / ,'

; .... - .

for · ~ork length t~ total length... Total .weight was ~e:asured to the -~ . ·

nearest o •. o(kg ~si:ng a· Chati.llon ba_lance. I ' '' · • , - ' "'

' 0 ' ' a r ! ' . ' ' • Sex and stage of maturity were .. determi.ned by gross inspection · . . . . . . (

of·,the gon~ds. Males were designated immatu~ if the testes were

smal.l~ narrow and th~ead.ljke~ .'and s~~~ed.:nb sign of vasculari·z~ti~n. ~ . ' ·. : ~ ' . . ·. ' ' ·. ·. ' . : ' . ' . '. . .

Maturing .males _had lar:ger, prominent, highly v_as_cularized tes.tes. · .. . ~

The testes of spent ·males showed this . vascularization but .were : fla2t;d a·n·~ not a~· prominent ~ :.·.F~males w~'re desi_gnated -immatur~ if

. the ' ovaries w~re· small and narrow,_ with mi~'ute eggs less than 1· mm

. in ·diameter. · . Maturing ovaries of fema,les . wer~ ·-larger and very . , . , ' - '

\ ' \ ' I

prominent, filling · muc~ of the body cavity. The ·ovaries of spent·

female~ were large, flaccid ' and 'bloodshot, and somet~mes CODtained

a few ·residual eggs .. · -1 '

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., The s.cales were examined using a Bausch and l'"Onb 'mic o-. ' . ~~ . ·:' . . . . . : . . . . ' . . . ' .

projector. (22 x) and aged (lccording to the method of Wil iams . '. , : ' I ·:, / , .

(195~)· ~ ···Drawings 'were made of ea~h scale ~nd annular increments . .

' l<o ~ ~- I • • ~ C"'..-.-:-{- • ' ~ ' ' I ' '

of ·_growtJFM~re measured from these ·drawings. The opercula_ ·and ' . . ~~~i~}'.}. ' . . . . ·, >:- . • • • •

. cleithra.1~·~ examined using a Bausch and Lomb dissecting ; ' . . . . ' ' . '

. I

mict-Qscope _(6~67 x). The: epercula were aged. according to Frost • ' • • • • • ' • .. ,, l \ ' ' • •

and Kipling (l9.5~L the ~jthra ·accord.ing to ~asselman {191'4)~ ,. . lti ···.; • . . : • . ' • • . • •

For botn operc.ul a and c1ei. th.ra:~ annul a·r . i~crements'· of growth·· were • - I "'

measured using . ar:~ _optical micrometer. Pr'io·r to aging·, the·· ' . . . ' : ' '• . . ' ·.. . . . . . . . ·. · ,

:~ otoliths "were · g~ound and. bur~t", a mo.dification o(the: techniq.ue • ~ • ' ': : ' • ' • • • · ' ' •' •·• . . _,... -- · ,..,... .... . • • • • I!

. outlined by Chr.istensen .·(1964).: · The Jatefal surfaces of the . . . . .. ... - . .

otoliths \'lere polished usi·ng· a·~w;t' stone.; the otoliths were then • • ~ • ', ' • ·, 0 __,.~J-"' ~· .- - I ' I ' ' ' ' . ' · ~ , ' • '• . : • • • ' • ·_

placed on· a hot rf:>lale at a· temp·erature that caused them to brown • • ' ,..... .......... • •• p ~. ' ' • ' ~ • • • • • • • Q • • ~ '. : • • ' \ - • •

in about~2o · sec. They were droppe'd iJ'111lediately into 95% 9lcohol ~ · :., ..... " ....- . ·... •' • ' ·. . . then he-ated again, dropped· once rrore in alcohol, and alldwed to . . ' ' ~ . .

. I

~ool. When ex9niine~~· th~y were ifumersed .. \n -.~lcohol and v)ewed .. . . . '' \'

against a bla¢k. back·~round (Schott '1965). ·using a Wild M7·binocula·r-- J . . . ' . . . "-.; . . · .' '

micr~scop~ (3.0 xJ.. _.}he otol{th_s ·we~e · agec!.'according ·to Ch~iste~se~ . . . ' ,.

{1,964_) a·nd· resch. {1968). Each. otOlith i~age 'was drawn, using a

camera J uci da· attactied to ,the mi c~oscope; ~nnul ar ·growth . \ . . •/"'

· nieasureme_nt·; -were .ma~e· from the drawings (l~acKay 1967)·. ·. . . . . ' . : . ./ . . . . • : : !

· To, determine·. growth, total lengths ~nd annual growtt) increments ·· ' . . . . . . ~ . .

. of'· the aging structur_es were · measured"... T~e. radius o'f ·each aging ' , . r • , , • ' , • • •

. structure was meas_ure.d from_ the mid- point of the 'nuCleus to the ' •. . . ' - . ' . . ..

• : .!:; . · ~-argin . along a ·sta?dard axis: The distance ·from the· nucleus to each . -··. . . '. ·.: . .

._ . · ,· .• ,· ' . ' . ,, ' '.

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·annulus ·was also · rileasured· a·long ' this a·xis. The opercular nucleus._:.'' . ' ' .

wa~ chosen .. ~s the · po~nt where a line drawn' Jrom the opposite .

indentations of the articulating nnubn is -biseciJd; mea·s~~e~nts ' . - . •' . . . ~- .

. I ' , , ' , ·,. ' ,

were made on the · concav~ ,(inner) surface of. the bone at·.ri,ght

angles . ~~·the line used in locating the .chosen ce~tr.e (Fr~st ·,. . • . . . ' . . . ' . • • • ' • : . . • . 0 : . ' • . ' .

and Kipling ' l959). · .The cleithr~l. ·radius was ·measured from :f:he .. _

or.igin to the p~int whe'r~" the t.ip of the an~eripr bl~de inters.~cts .. ' - ' ·. , ' ' ' ' ' f ' ' ' • '.. ' ,• ' ' , ' • ' ; t_ ·:; '

· the. 1red1al cos .~a (Casselman ·1974),. ~ The origin was cho.s~n .as the··: • • (l · . . , - . . ' • .

· point of i ntersectipn of two lfnes, one 'drawn· along ·the medta_r · -•• ' • · , ' . . ' 1, . • • ' • • ' · • .

·CO~ta , arid the . . othe·r along'the 'inter1or ni~rgi· n · of -th~ ,bone. frQm : . .. · . ' ~)i ' "' • - ' ' ' . ·. . ·: • '

-the 'ti .p of the dorsal spine.'' . . Otolith . radiu·$ was ·~a~ur.ed along an -' ' ' ' ' ' " ' ' ' ' . ~ " ' .·' .

. axis from the nucleus. to the . edge of t~e .Postrost:rum~. · ·

T~: l:fack-calculate growth of pike~ the ~ctual ·relationship . . . : . I . . , : . . '

b.etween the grm<~th . of each · agir}g. stru~ture and the length ' of the -

•' .

·' l . . . ~ ' . . . ~ \. . ' . • ~ ' ..

fish was de.termined. )ndi_vi.dual · tis~ ·len.gths a·nd .the corre.spondi~g ' . . l"' • , • I f:i 0 : •. • • • , # • ,

.. aging structure 'lengths were used · to calculate these · relationships. . -:- ' . .. . . ' . , . ' . ~

Linear and · cu~viline·~·r bcidy~;· .. aging s.tructure.· relat1o~ships .~~re . . . . ' . . . . , ··,

. deri veil; the· curved relationships were used based upon .their .higher . . . . . . . .· . ' ..

correlation coefficients. · Each _of the .expon.ential equations was

co~verted to a strai.ght.lirie. _ using ~ the fol'lm·ling transformation: . . . . - ' , . ' . ·._ .. 1 o.g _: 1 = l -+ n . ( 1 ci ~ S ). · .;. ..

.. ' '

' ~ .

! where 1 is fjsh length, K is the ¥-intercept '(in log units)·, n is

, I ~he· slope of th~· _r:elationship · a~d .S. is the- length of .. th-e aging .

.. ..

' .'

· structure (14onas. tyrsky i.930) • . . ·

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Back-calculated age-length relationships we~e determined . . ;. ! . ; . .J . ' • ~ •• ' ' ' . • ' • • ' • ' .. . . t • ' ' • • · ,, •• • • • \ \

. ·, by fitting ave_rage annular aging · structu~ le,..gth~n th-e '-.- . . ·. : I I • '

' a~propri'ate boqy.; : ag~ng· struct~re regres~ion. ·. ' • • ,t I

·-.· ' . \ ... ' \ -· ~ ' , I ' "\ I I . . . ~ .

·. -< . '· ' '

. ' , '

test the _·age-length ··regressions generated ·by . each of the · a ·

methods. ·: Th~ :cov·aria~c~ ~nalysis'~was tis~d · f~_r ,com~a~· a- ·- of - b~tf( -·" : . ··<J.-. . . ' . ·,. . ~ . . . ~. . . - ·~ '~- .·: .• i .

· sl_opes ~nd ~d~·usted mean.s. - • , Als~; .j:"·. ~-?~e. c_~ses, . ~r _:. . .. . _·\. _ _. . J:-~·

.regr~ssions:·· were -~nipaf:~d simul taneousJy. · By· co~ r.ng 'adjusted··._ · .. . . ·-· .- :· ·. · . · · ·. · !_ ~ -. \ . ' : . - . . · ···. . . . , -- . ' : _·_ - .· - ' . .. · .. · .. .

, ·.. , . ."~ II , , , ' .

· ·· 'Analy'sis of covariance (Zar 19~4) was used ·to statistically .· . .. . - ', . · ' \ \ . .. . ' .. . . ----t---

-..

•'.

·· .. ,· . . . . · . - ~~ans~he _ ~leva~io_ns of the regressi~ns _we_r~ c~m ~r-~d -. . Ad~usted_·_ •

:'·

inean~ were tested onlY,. \ f the' slopes PT the regre sions .were-. . ; ~-. . s.i gnff~~at:d;ly :~ifferen~rJ . The-te,for~- , i.f e·i:th~r th s_f~pe~ . ~r - : :.

. · . . ·., , ,. ~ · .. Q/ \' :.' , ·. , , . , . I · , .. ·. ,I ·. ,' ,.

·adjusted ~aris.of -t~e lfnes differed s_1gnifican y _ a~t p ::: -0.05,-

i . . . ( . .

. •·. . ' . . i :; . . I· . . _- . .., · . .

", . . . . : ~- . l- . . . ' . \ .. ' ' . .. ' ,' ~

_, . . ' ' ... I

. t

the reg~essi'ons were con~i,dered significantly different. . . . - ~ . . _; :. ·. . . .· , . :. . . " : :. - . . . . . . . . . . . . .: .

·: __ · The coeff-fcient of condition· was··calculated. by· the following · ·. · . . · · .:

--; · :· ' ~ .

. .. ,-

·' .

. ' /

. .

. , 0 • • • • - . • •

equat1on~ ' . " -' . . . ;

/ ·' ' . 'l . .

K =· w_.x ws . . . .:··.-.. l.: 3 .. . · ·... . . . ~ . -~

' - · Jher~ -w is_ whole · ~~i~ht ~kg}. --.1 is fork' length (cm) .and· lOs · is a · , .. ' I . . • . ' . _· - ~ ·, . . . . . . '. · . . .

•o . - constant Which allows K to assume a val~e near _.unity (Hile. -1~36) •.. . . ' . . ·: · Ovaries fro~· 49 ripe females '.~1ere preseryed ·-;n Gilson's flu.id .. ·.

\ • ' • ; ' , : ' • • ~j • - • • • _l ' '. ... . . ,

. (Simpson .l951). : Fecundity was· determined for 32·ovaries US'ing· an . .. . . . . . . . . ' . . - . . . " . ' . . . . : . . .. . . ' ~"' . . . . . . '

e 1 ~'c troni c DECCA batch count~r ' (Bc:>.Yar and 'Cl; fford 1967 Land :tor-. ' . - ' \ ,• - . . . . . - .

. - .. . . . ' . :~1: ' " . .0 ;_

· .:J-·1 .

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ol . -:. ' !' .

.. ' & , • . I . . -.,. .

~ . '.

.' ·

.. . . . : . -~

/ < ' the r~maining 17 by yolumetric .displa·celll!nt ~(Kan~le·r - ~nd Pi..Witz , • -:_. ... . ' . . "' . . . , /' . ·~ ' .~,. '·. .'· . : -~ .

,, _.

l957). The volumetric .method -was used fcn~· ·-those . ovar-ies · in .w.hich··. • ? ' __ ··-: · ;·: · .- .. _~ ~ - ~_-:_ ·,. - . ' .· :· . ~.- - .. :· . .'· ._·

egg casings were · too decompo_sed by the -Gilson's fluid to -be .coonted ' . "' I • , • • ' '

electro-nicafl.y. · Egg nUmb~r ~as. e:stimated _twice_;. usi'tlg the 6atch _ ., . • . P,, . , ' , - - • , .

. -. . ...

b ' ' .

.. '7 .

·• 1 ~ . . : ' .. .

, · l •

. . ' . .

r- .·

· • ,t

~~:~ ; i .

'... . l

. .,. . 11 ..... . .. _ v . . .... ....

. : ·· .. tJ · • '

I .. . ..

,

. -. ~- A .

•.,.·­, . . , ~~

't:. · . . •

.. , . . \.' . . ..

-~

... " . · .. . .

. , ' . __:./' 1'6~ .· ..

' ... !

'·

.. · . :, .. 'i . : ... .... -::... ,

·. ,r .• .. ; .

. i ,

·• : )

..

' . f :. ~

. ~ '

. , .. i ! t: 1 r. r !

..

·0.\ . j •. t

• D

I .

. . ,

/

' •,

'

/. '

(I

~) f .. '.., • . . ·~ r ~ .. f . il

( ~-

, ~ -

. \ 1·

\ i'

.• !

;· !

, .. , . ·:

,

,. ' .

f . ,.

· I

·. ·· .. ••.. . -t

. -· --·-.'.

-: . < '

. . . • , • . .o . . · .. , . . . . .

. · cou~ _te_r~ :_ for . a - ~.-~bS-alJlpl:.· of .f;v~ o_'-:ades: _ Esti.ma~in~d .f~~ .

the .two runs· de~ated less t~an 3% . . Egg count est1mate·s. on. a • • • • • • " • p •

. • . ' ' • • ' • ". t ; ··• · _ - . • • . .

subsample of 'five ovaries .• us·ing both the batch· counter and volumetric· . . . ' ·.· . .

. method, de vi a ted iE~ss than. 10%. ·:

. . t . . '

The .degre~ .of . full nes~ · of the stomach and its contents .were . . .

. .. . . ' ~'·! . l ••

' recorded· for a sample of 386 f]sh,. Fr~quency of,. ·occurrence was used

as a qua.;1 i tiiti v~ -~thod of f~o~ ana lys i_s •. · I .

..

' I ' . ' ·, . . ·\·.

' '

. \ .

• , '

! . '. ) .·.

: . ~ , I

'.

.,

.· - ~ ., (

0

;-/

; '

./ •"

' .· '.; . . .

• • ' o.,.

' /' ' . \ ·1 ~I '

. , .. .

( '

. . ; ·; , ' 0 '•

. . ···-----· __ ,_ --- - ------·-··. . , . . . .

' . . ~ -.... ' ,•

'\ . '

i ' \ (

..

..

I

t. !

:

l ·l

- ~ -:~ .il ..

· ;t

j ~ I l :J I

' I ' i I '

j . '

. ' .. l '

?r .. ,. I I . . l l i '

..

. ·.

I

. • ' . , . · 0 ' -.... :

, \ ., ; .,.· .~. :....,_ .·. ::._.~ •• ~~-·~: _ _ ;_;, _ _.:~--_;_~~-~ ~~: • • ~~ - :.;: • • :. · .~_:_;_..;.~-· -~~-:-~----•--•·---~-,-- .. -".- " I ~ •• •

. -.. . Q

.. ; .

' • : J •

.... ' I

•.

:

. ,

'

i ' ( ~

. -~

I

"~ I '

' ·-,

·· ·i ' !

I

.r

I. r

( .

' .

.. .., .. . .-. ·. -. .

... . '

. · .. - 17 ...; . ' /' ..,.' l

.. ' J·

· "'· . o I ~

-RESULTS . ....,. . . ;· .

' ; ' I

.· / - " ,'. ,.- ·

j . . -~· ' : . . . I

. I ' . -; ' .

. 1. Age .determination '<t.u

,. 0 ••

f' •

:

..

. ; ,..· ,;..,

... .,~ ... ~·

.-. • ,I, w

- . .A - . . . . . .

Th.e .empirical .r~lationships between the' length of each aging . 1 ~ ' • ' • , , • ' 0 . , . , ' ' . ·,.

•

0

: ... • • • ) structure and. the_ length_ of the fish ~~e _ p~esented in Tables 1-4 . . . / ' o, • - ' • "

'

~:.

·A

·;

. : and Figs. 6-9. · The . regressi an ·lines are graphic _representatio~ . . '

~- .·· · of the calculated regress'ions (Table 5}, ~1hile_ the scatter plots . . . . • ' .

. ':o r

--.. and ~anges repr.esent tbe empi t:"i cal data · of average fot:k le·ngths . . ( . . . . . . ·. . . . ' . l . . .

and _average length's · of the . pqrticular aging structure. Regression:· .

eq~~tions were _c-alculated for ·sexe-s separated and c.o~b-ined. ·. All·· . . . . . -. . .' . ' . . . )

aging· s1ructl.lr:e lengths in Tables 1-5 are magnified }engt}Js. It • . .

Empirica 1 an'(back~cal cul a ted age-length· data are presented . . - - _ _,., ':e . .

in Table~ 6.:9 and Figs.l0:-13. Sca·tt~r plots and ranges represent ·.

"'empirical .averag~!ork l~ngths' at a.ge·; curves ~epresent bac~.-

.·calculated relationsh-ips derived from ' the appra~ria.te .body ': ~aging :

stru~ture regression (Table 5·)·. : . '

.-Analyses of covar_ianc;e · were ·used ,tP :tes·t for significant

· : . . I ,

· difference at -p .:::· 0.05 .between slopes or adjusoted ·means for the . ~ . . . . . - , ··, . ' .

, following·age-·l ength n:!gressi9ns:

· · ·,Regressi_on·

males v~. females for each aging metho<l; einpirica 1 and _tlack:-cal culated·. . . ·

, Q. • ' , r ,. . I

· eni'pirical vs. back--:c~lculated for each aging .method; sex_es separated .and contined. · 1 .:

: J.'I

10

11

.. _ . ,, .... - . :· sea les vs . ope.rcula 'vs .. clei thra vs . . otoliths; empirical and· back-calculated;

.f2

sex~s~ separated arid combined. · ·

. : '!

' :· . .. . - ........ ------~ ~ --• I

i · .

. · .

..

' - ;.. ....

"-

I

'

.1 • •

' I

' I . I

!· ,I

'

J

l 1

I 'l : i

r ' ' I

,.

·.

.. ~ . ~-f_

f f - f

L ( t.

f ~

. . ·.f. -· f r ,·

' r .

. : ._,; . \ '.-

' -.... ' ··- ;_' ..... ,. .. ., ... -----· :-·"'·-·----:- ..... -· .......... --~ .... ~··"' ~·· .. ; _____ ...,, _ .. ____ _ ,. , . . . •r·-··· -•-- •••··------' --- - ,, -

"I', \i •

I .

- .

<;'

.- 18-

.·.

Regre~sion

. - . / - . otoliths vs. scale~,· . otol.iths vs ~ cleithra,

I ..

I . •

. '

. . . .-'!; .· · Table . No ..

. --'--l3

'· otoliths .vs. operculcl, scales vs. opercula, · scales vs. · cleittJ.ra, and opercula vs·. clei.thrai back-calculated; . sexes separated · and combined. : . ' . . .

\ ' .. /

-· . ' "

Empirical age-length regres·sions for.males did not differ · "'- . . . . . . . . · significantly from· females, using ,any of the· four aging methods .

' ,\;.\ ' ' I > t, ..;'

·{TabJe 10). The difference be~een back-calc~lated age-length ' . . . . '

reg~~ssions formal'es cy1d females~as signifi-cant, for each of .. ' the four: agi-ng me.thods. : . · . ' '

. ~ -

I \• 'l

,Emp!dc~l .and bacf- calculated a~e .. le~h- ~egressions !diffe'rd ' I • .

· si gnific.ant1y : using/ seal es, opercula·and clei thra (Table 11).

' However, using.otoliths, the difference was not significant. \ . .

' . . . Empirical age-leng~h regressions did nbt differ signifi-cantly,

- ~hen compad ng a 11. fou.r aging. methods whereas _ baek-ca 1 cul ate d

· regressio_ns did differ signifi~ant1y . (Tao'ie 12); . . For s.exes . . I . .

separated·~nd combined, the back-cal_culate'd age-:-l~ngth _regressions

,generated by each aging method diffe~ed sig~i fi cantly from · those

.. generated by any other method with one exception; fo-r )\rna 1 es, ' .

the, back~ca) culated age-length .regressions,_ using. oto1Hhs or -scales,

~i d not differ significantly _(Table 13).

II. · Bi ol ogi ca 1. s tudi.es

A:• Size and age •compositio( .

. 1. length ' ·

., . T~e fork length distribu t ion (Table 14} · is uni'modal with the _

.. '' ;. ' ., ~ ·

: ' .

.(

I '

. \ J i

. )

.. - ~

) \ 1

) '

..

- . ~

~ ...

i · •

J

l

. L..i

} . . .. ------ ·· - •-<• "0. -v-•1 - · ~ ~ ••- # ~ • - . . .

I i •• f • • •

I .

· ' . !

1 . • I

I

.,

·; 1

I 1 .i

! .

. '

. I

. I

-•'

·,

-.. \' :, . \ . . .

Table 1. -The relationship betwee_n fork length ('em)' and magnfr{ed ·(c~ · ~ 22) scale length of northern. · · · pi. ke fr~f!l Lobstick, Labrador. . · . · . , ) · · · . · .

( - . Fork 1 ength ·

. · (em)

·- 1 o.o .. . 14.0 .

18. 0 ;.·

22.0

. 26.0 30.0

. 34.0 .38.0 .

. 42.0

.46~ o. ·~--.,: ..

.~o.o ·

54.0

. 66.0

70,0

74.0 ·78.0

82.0 86.0

.(}

Males

Mean . Range

. 1. 3 '1. 2- 1 • 4

. 5.2 6.9

-.

8.8 .. ·'.• 8.6- 9.0

9.8 ·' 8.9-l0.7

1 0 • 0 . 8. 8-11. 5 11.4 10.6-12.5

11.9 ro.3-l3.l 13.4 12.4-15.7

13. T 12. 4-15~ 6. 14. 6 . 1 3. 4-l6. 8

14. 8 1 3 ;O-1 6 , 5

15.3 12.3-17.4 -18.4

·-

. -.. -- . Scale· Length (cin x"22)

Sample Size

.. . 2

0 . ~

0

0

1 .

0 2

7

3 9

14 - 16

14 . 17

.19-.

3 l

0 0

Female~ ___: __ ........).__--..S,-am--p-.-1-~ . ··

Mean~, - Range · . Size ·

1..8

7.7 8.6 . 7.9- 9.6

1

0 · 0

0

-o 0

5

9.2 8.8- 9.8 . . 3 . .

' 10.1 9.7-l1.3 11-.1 . 1 0.0-ll. 8 .

12.0 10.9~13.9 ' 12~8 11.8.:.13.7

. .

5 ..

5

·9.

:., 13.4 ' 12'.1-1(3 . 6 "

. 13.8 12.;4-H?.4 ·

. 1 5 • l 1 2 • 6-1 7\ 3 '

. . )5.0 . '13.4-16.2 1 5 • 7 . 1 4 . 4~ 1'6 ·• 8

. , .

. 16.1 13.5-17i5 -18.6

18 '

18

, 3 . . ·-. r!' .

·.A .

-·

C_ombined

Mean Range. ·

·1.5 1.2- 1.8

-5.2 6.9 ~

7:7 .8.6 7.9- 9.6

9.6 8.8-1.0. 7

10.1 8.8-1.1. 5 . 11.3 .10.-0-12.5

l2.0 10.3-13:9 . 13~' 2 11.8-15.7

13.6 12.1-15.6 _'14 .• 2 12.4-16.8

J 5;0 12,6-1 ~. 3

15.1 12.3-17.4 16.1 14.4-18.4

16.1 13.5-17.5 ' 18.6

Sample · Size

3

·.o 0

0 \...

1 ..

1 . . , 7

10 .,

8 14

23. 22

20 35 .

37 , 16.

' 7 . .... l

7 1

\

' '

• • ·~~ .... ..... .... _ ...... ~. ~ .,,::...: , • • h~ .... -:~·-··&dC>'1hA!:t' '>·Cvr i ; ~·.,;·r t i'?i a-

' I .

. ' .

. : i ·:l . . I I .

! i . . . ~ ~ I

. i

.I t . l: •i

l ·. I

l . l i I f I .

. '

I ...

.\ . . . ··. ·- ,, e -·. ·~ . -: ~-··:· ··· -·---·-- -~----~:- ···-·--------~-------·-r·~-- -.-.. . .. - ~-- ----~---_.....~--. --. ·--~-~~--- ---

/ ·

• I

. ;

I ·

. ;

. .

.. \ . '

ao.o ·

j . . . : Q 60.0 . ....

.=· -401 b.Q ,

~ 40.b . ~

~ -1'4 ' e

Jic '2 o.o

- . ~ ·.

i •. ~

' l:l

:

I

i l .l ! .I : ; '"

()

I ' 0

,, ' ,. 1-

...

. '

. .

·•

. , .

( I '

- I

f·1ALES.

'L. = . 7. 1647 s· o • 821 3

r = o·. 97

. I

s~o 10.0

... ~~.0

. ./

60.0 t .

'-· . .

.. '40.0

' 20.0

20- . '\.

I .

-F~I·IALE~ L=5.4oofs o.9 .. 9o _

{ I .

..

15.p 5.0 ·10.0' :15.0

SEXES COMBINED

L =l.4S21 s 0 . 8711

r = 0. 97 /

,.

.. . 5.0 10.0 15.0 , ',f.

~ :. Seale length (c~ X 22) ,. . . . . . .

, Fig. 6. Empirica-l . (scatter plots and ranges) ·and cal.culiited (fitted curves.) body length:.scale length relationships of ·northern ·

·pike f rom Lobs tic~, _Labrador. 1 , ·

·'

...

.. ...

~

\ I

. · ,

• .

.·

. (

! . . i .

. ;

·1 '-"' ·~

. rJ •\

.:J

1 . :f

-~

( I 1 . • ' j .

.. I

1 ~I 1 ~

·. ·.; I

.' :1 1

J q

. ~l . . :'-.~

I j.

1 ,·' ~ , .

)

i . ' . ' I

.. I

- . i ;

____ .,...,_., _______ ~~~---· - · - -·-- · . ----· - ---~ .. .... . - -- - - --~ - --- - · - - - --- .. - --. · : · --- . ·

.' ' ' ~ .. - . \ . :-:.. . Table 2. -The relat'i.onship between fork length of fish- (em) and magnified (em x 6.67) operculum

- · ·length of JlOrth!'!rn pike from Lobstick, Labrador. , n

Fork 1 ength · {em) ·

' .I ..

. ~ .... _.

10.0 14.0 .

.. ' J .8 .• 0

'--,.· 22.0

26.0 30 .. 0

. 34.0

38.0 42.0 "'

\. 46.0 ' 50.0

54.0

58.0

62.0

66.0 70.0

74.0 78.0 82. 0

86.0

_,__~'----- ~ -.. ·- ~ --- ·- •.. -·-- . . "· ~ ~--·-·

Mean

3.4

.8.9 ' 10.1 -

13.5 14.6

14.9 18.4

19. 1

0 20.7

2L8

23. 1 24. 6 ,

26.5 27.8

Males

.Range

' 3. 3- 3. 5

·' ":

-' 13.-0-13.9 .

· i3.5-ls.s

~ample Si_ze

2 0

0 0·

1 1

.- 0

- 2 1- •

14.3-15.5 .· ' 3 17.1-19.8 9

-18.4-20.5 14

19. ·5-22 ~4 16

' 19.6-24 . 4 14

20.7-24.3 --17 23.3- 26.5 19

· 24.3-27 .a 3 1 ' \

0

; . 0

· Operc-ulum Le~gth {cni x f?.~7) .. Q Females·

Mean Range

~- 7_ -

..

\ -.

-11.8 '

l3.1 12._1-13. 6 · ' - 14_. 3 13:-7-1_5.0 .,

16.5 15.7-17 .0 1 7. 5 ' 16 •. 6-18. 0

19.4 18. 1..;21.3

20 . 8 . 20.2-2l~ 5 .. ,;;, 22.3 21.4-23.6

23 . 6· 21.0-26.1 25 . 4 22.8- 28 •. 0

25~9 23.5-29 .o ' .26.6 25.8-27.2 -. 28.2 27. 3-30-~ 6

' 31. 7'

Sample , Size

l 0

-: 0 0

0 0

1

_5,7 3

5

5

9

6 6 -

-18 ' 18-

13

6

7

1

'\

.. ' '

. ' . • • " • • •• . ... .,o • :.. , - .; • ...,. , • .. . . -~;,.-,.,~ ... - - :. .. :.;r.~ <".t:"~4 ".;.~'1,.':o ....... --..>-'_.-l '.l.~ •~'-'-.. -,

.-

. Combi ne d _

Mean Range ·

, 3.5 3.3- 3.7

- - .. -a.9

_loy ' '

11 .:8

13.2 12-.1-13.9 .14.5 l :t 5-15 .. 5

15_.~ 14 ;3-17.0

18.1 16.6-19.8 ~ 19.2 . 18. 1 ~21.3 '

..

20 . 8 - 19.5-22.4 21_:9 19.6-24,4

23'. 3 20. 7- 26.1 25.0 22. 8- 28.0'

26.0 '_24.3-27_.8

26 .& :25.8-27.8 . ~

28. 2 . 2 7. 3-30. 6

31.7 : ? .<

Sample -Size

·;y 0

·a 0

1 -1 -

' 1 .-7

_. 10

8 . 14

23

22 20

35 ' . 37

16

7 ' · ?-

1

\

:J• ' .

_.,

' \ \' .

- . - \~ ' . '

' . • ' ~ I

1 .

:-. '

{ .. I . l l 'l

I

1

i : : . i

i i -I I ! 1 ' i ' 4 J - . I

·, '

1 . I ! . ' 1' I I l -

' ! ' :

.. _.--./" -

. · . .. ', ' . ,

. ( '. ' ' . ' ,1·. -J: ••• .. . ... - .. ~--·· · .. ..... _ . _ ____ .... ___ ............... ___ ..,7"~ ------ - -· .. ,. ·. ·:·

· . . · ,

MALES · ··

' II . ao.o. . L =. 3J l's3 s a. 9104

r = 0.99 -.- s C) -

~ .':

60.0 .

~ ~ . bJ)

' ~ ' CI) 40.0 . ..... ~·

- J.4 . 0 ·· .. .. . ~ . '20.0

' . / ~

.. I.

..

22 .-.·

FEt-.1ALES

L = 3. 3274 S o .-9479

r = 0. 98

/

I ·

•

• I

.·j

...

.. ·'

... ;~ ' :~.

ill .:l . ~~

. ~~ . i ~

L . ·1 . ' . ~ .••.. j

: ~

.; . ~ / . ( .

\ .

:.

I •

.•

i" j • {

~ ..

. / l !

. j

'!-. I i

. J

l.

.,., ,•

..

./.

· t .

·Jo.o

' ...

I . •

~0.0

...

60.0

. I

40.0·

20.0

I

20.0 30.0

, SEXES COMBINED

L = 3 ~ 1908S 0 : 963o

r =o ·:gg ·

)

\.

10.0 : 20.0 . 1 ... ..

/ .

. I .

20.0 . - .30.0

Operculum lgt (~x 6.87')

ao.o

(;

' I .

Fig' . .7. · Empirical . (sca tter plots and r anges ) . and ca·lculated (fitted . · ' curves) body length-opercul um l engt h r elationships of · ·

. northern pike from Lobstic~1 • . Labrador. · :

L.

<' ; : t '. ,..

• f

- - •... .- I

.. ·- ..

.:.

. - .

. . r . • $

.. · , • • !

r· · ~ .. ;

. :.

. .. . : .

.! :.

I .

....

• !I"':'JJ'J •. ~ '"":t,t; All P4]4'\UJQ4,t Jiik4q¢4(qq ...... _ .... . • - · ·--· - · ' ·-. ··:-- ~ "-'_' " .. ----. ... - • •• v . ' ... ' ........ " - -

-·

' ' i

• '

. ~ .. ·::<-... <~;:·~: ·. . . ~ ·· ·· . ·-~: · ... ... ~ . ·-., ~ . · · '

3 . The ?relationship 6etW~en f~rk length. of fish (em) and ·.mag~'/'f~e9~-.(~~:"F~'G:67) clefthrum Table . .. - ·Tength of_ northern pike from .lobstick, Labrg~dor. . · · . · , .. · .. · : , . ., . . :- . · "' ..

. . . ., . ~ -:-.

Fork length · (em)

10~0 .

14.0

18.0 . ~-0

·--·26:0

30.0

34.0

38.0 ' 42.0

,46.0 50.Q

54.:0 _-_,·sa:o

62.0

66 •. 0 7p.o 74.0

78.0 82.0

·. 86,0

. .

Mean

: ~ '6.9

18.5

21'.0

l -. .26.0 27~9 -_,.

33.8 3i.9 35.9 -

39.5 ., 40.3

' 43.6

46.4

47.3

50.0

. . Cleitlirum length . {em x 6.67) \

Males Fema 1 es · · Comb.ined

Sample . Sample ,_.Sample Range "' Size · ~- ·t:fean Size . Mean · Range Size

6.8- 7.0 .2 a·

' 0 - o

' - -1

1 0

25.0-27.0 -2 26.5:..30.0 - 7

30.0-40.5 3 30.5-36.0 9 \ 32._5-.<1-2',0 '14

37.0-43·. 5 -16 36.0-43.0 14

41.5-45.0 17 I

44.5-48.5 19 42. 5-S,Q~O 3 ...

1 • . . '0

- 0

. '

~-

II

7. 7 --

22.5

26.3 25.5-27~0 27.7 - 27.0-29.0

30 •. g 30. 0-31. 5 1-

·32.8 30.5-35.0 ' 36.4 34.0-38.5

·38.8 37.5-39.5

1 0

0

0 0

, 0 -~ 1

5 -3

5

-5 -9

6 .39.8 35.5-42.0 6

43.5 40.0-46.0 - 18

45.5 35.0-48.0 18 ~8.0 '43.0~50.0 . 13

49.9 .48.5-51.0 :52~0 47.0-56.0

60.0 " J•

6 7 '

·. 1

..... · ·:

7 • 2 . 6 • 8- 7. 7

18.5 - '

21.0 ' ' 22.5- .

26:2 25.0·27.0 "- 27.8 - 26.5-30.0 .

. 32.0 30.cf-:40.5

33 ~5 30. 5-36. 0 36.1 . 32.5-42.0.

39.3 . 37.0-43~5 40.1 35:5-43.0

43.5 40.0-46.0•

45.9 . 35.0-4~.5 47.9 42.5-50~0

49.9 -48.5-51.0 ' 52. 0 4 7 ~-o- 56. 0

'"So.o -- -

<

.. 3 0

0

0 1

" 1 1

.]

10

8

14 23"

22 .

' 20

35

37 . ;"

16

7 7' ~

l

- _/ I • - -. . . .,J -- '

_:.~ .~..:_~--~~.C.-"-'-......... ""'""-._ ":"i ~ _... ' ~ _·_::*o ; ._. ~

-N .w

. -_ ·._.. _(

; · .

' ' l .

. ~ . i .

' 'l ; -! . . 1 ·. 1

I .j \ ' ' 1

' -~·t ··· . i

f

? l I

.J I

'· ;

'.! ..

I I _

• .

.-

I •

I I . I

·­·'

....

. I

j

' . ;

\ < ' .

. '

' . ·: i

~ . t

I

t '·

i !

/j

l I I . •

·: .

. I ·~·- ..

: . .

..

·,

.. -. .

-. \

...

'

/

\ .

;~ . ~o.o

·-·.a : . ~ 60.0

2o.o .

. I'

. '

"/:' .

!. ·-

I

.· \

Fig. 8.

" . \'

' - ~

" . - 24

· \

I . . ·I

t-1ALES . . FEMALES .. \ . -

l ;;, L3820· ' ~ _1· _02 38 , I ' r- = .0.99

.L = 1.4122 ~ - = 0.:9.8 -

L. .

• ' !

,-:

. . c( .

\

\ '

20.0

. 60.0

40.0

·20.0

-. ~

·40.0 ·. , 60.0 /

SEXES COMBINED.

L = 1.3574 S

\

-20.0 40.0 . 60.0 ' ' I

-Cleith~m lgt. (em x 8.67) . .

40.0 601J

. ,

l .

:. "

Empirical {sc.atter plots and · ~ ranges) and calculated (fitted curves) body length-cle-ithrum. length -relati onships of northern pike f _roril lobstick, labrador. ·

/ ' :,\' . 1

-,

.. .

- '

. . · 4

/

I ,

. l

_. \

. .

. ; .•. -i

. '··

l < _,

"·· ~ l .1

' . .. ·. :

. , . .

1 ' ...

. '

.·.

I· I I ! · i .

. . ; .

...

. : '·

. . . . -- .., • • .. -·- ·•• .......- •-r·-:-'-• ·-.~-- ~ • - - •;'• • .,. •' •• -· • - •

~ '·

\

. ·rabl'e 4. ·The- relationship b-etween fork lemgth olfish (em) a·nd ~magnified (i:m ·:x 30) otolith . 1 ength of northern pike from Lopsti ck; Labrador. :.. : . ~ ·

· ·. Fork length r (em)

.-. ·.· 10~0.

14.0 18 ~0

'

22.0 26.0 ·- .

\ ~0.0

34.0

38.0

42.0 ..

46.0

50.0 54.0

58.0 . 62.0

-66.0

'70.0 74...0

78 ~ 0 . 82.0

86.0

Mean

1 • 9

4~8

5. 5.

6.4 .

6.7 7.3

7.6 . 7. 7

8.0 ._ 8. ~

8.8

9.2 9. i

.1 0. 3

l .

G

- ' <

Otolith Length (em x 30)

Mean

1.8

5.·0

6.5 6.6

,6.8

.7. 5 7.7

8.0 7. 9 8.2

8.8 : 9. 3 ,

9.4-10.1

11.2 ..

· Females

Sample Ran·ge .- Size

' .

5.9- 6.8 6.5- ·6.8

. · 6.4.:. 7.6

7.1- 8.1 6_. 8- 8.5

7.0- 8.5 7.5- 8.6 5~2- 9.4

7,.8- 9.9 8 ',5-10.0

8.7-10.0 . 9.1-11.5

1 .

0 0 ·· .

0

0

0 1

s · 3

5 "- •

5 9

6 6

18

: 18 - ] 3

- 6 -7 .

1

· · .. Comb;i'ned .

.R.ange Sample Size - .

1. 9 1. 8- 1 : 9 . 3

4.8 .

5.5 5.0 - ~

6.5 5.9- 6.8 6.7 6.3- ?'.4

7.0 6.4- 7. 7_

. 7. 6 6.8- B.B . 7. 7 ·6.8- 8.5 .

·. a.o 7~0- 8.7 -

,8. 1 7.2- 8 •. 9

8.5 , 5. _2- 9.5 . 9.0 --7.8-10.2 9.3 .. 8. 5-l 0 .o

9.6 8.7-10.0 10.1 9.1-11.5

'i 1. 2

0

0

·o . 1

1 1 7

'10

a· . 14. . 23

22 - 20

35 . .

37 - 16

. 7 7'

-1 . 0

\ '

N - U1 . .

\

' •,

I ..

. '

..

' ' o ·

i I ! -!

I . I

• I

! 1 . . ; ·

·\

--~ . \ i

. ' . ' \ ; .

i .

I·

I ·

·,·

. .. . : \

.-

' . . '

.' r. ., .

.. •.

. ' . l '

l I I

'(

l'

. . . . . . 1'

/ ·

: I' '1"' . , . . • ~¥ .... ___ ... __ ..... , __ .,_~ ... "'"'~'""":"l'•'"''f"'"'~ .. ---...... -~ . ....... r; . ...... - . .... __,....._.: ....... -- , • • - • ...:... .,.._.. • ·· ·· ~·~· ·;-· ............. --- '" :- - .. · ··-.- . ·· ·~··-.~-~ ..... -............. . ' . :

/ . \ .

( .

. .. ·

' ' ' I

· ' ·

, ; . ,lo ti'•

. ·· . . . . , . r .

\" . ' · . . -I

. ) .

26 - .

. ' MALES . ...

8.0.0

-! .. - :o.so .. o · ~

,.a . bD s:r · .

. .! 40~0 ~ k ./ . 0 ,. ..

~ ?0.0

. . . L = 4.2053 S 1· :2 5 8· ~.

r = 0.96 ·

' .

FEMALEiS ·

L= 5.1928

r =_ o.91

·"

.I . .

{ .

,· .

· .

' . .

\; '

' .

.. ) .. .

· ...

I .... : .

· .. " •

.. :

..... :

\ ·.

., .

Fig.· 9 .. . ..

... .

. 8.0 . •

ap .

. . . ..

SEXES COMBINED .· .

SO.Q . L = 4.4802 S 1;22814.­. . .

.·' r = ... 0. 76 ·

.so.o

' ..

. 40.0 ,,

20.0 .l

I '

'

.• 4~0 8.0. ' Otolith lgt: (om x 30)

~ . I . . .

Empirical .(scatter ·p.lots and ranges) and· calculated ('fitted ·curves) bodylength-otolith · r~ationships '· of northern pike . from Lobs.tick,· labr:-~dor . . : ·· .. ' . . . .

·~. ( (i) .

· ' /

• •

. . ·

... .. !

. . . /. .

• t!

:;::-.

., .

. . . . . ~

. .. 'l . '! . 'l . . -·~

:1 ·~

.. t . 1 .< ..

- < ' . ' ·

,r ,·• • •' '

.. . ·

.- · .'\. .. !

. i . ~

-~

.,

·) · .. · ~: ·· .. A'}

;.. -·:. -·.

i ,· l I

. ': i . \ \

' . .

. . ,/

.· ,· ,

• I 1·'

t I . \ . .

I .

"":---

\ .

\

, • I

. \ \

·"

-·

, .. j.,

'

. \ . . . ~

Table~ ·5. Logarithmic and exponential forms of the regression equations for the relationship between fish fork .length (L} and length of the aging structure {S), using scales, opercula, cleithra arjd otoliths, of northern pike from l,.ob?tick, labrador-. _

. .~ ·,

Logarithmic Form

. \·

' ..

Exponentia}-Form · · Correlation

Coefficien-t · . " .. . . .....

SCALES (em x -"22) . .• · _Males · ·

Females

. .· . . .

log L =··o-~a213 lo~ ·~ · + · o~:es52.> -. -~- ~ : ,;. ·i:·1s47 ·s -log L =·0.9490 log· s.+ 0.7324 L = 5".4001 s

0_· 82.13 -. . . . o··949o

Sexes Conibi ned log L = O.Q711 log S + D.8097 l ~ - 6.4521 . S 0·.87H

0.97 . 0.96 ~-

. . . . 0. ·g 7 ~ ' ·. . ~~· _.,_ . I .. - - (

OPERCULA (em. x 6~ 67) - . . . . ·Males · · · .. · .. • log L-= 0.9704 1og ·s + 0.4935

F_emales log L = 0.9479 jog s. + 0.5221-Sexes· Combined log L = o-.9630 . 1og s + ·o.S039 .· -

. . . \ " .. _. :

CLEITHRA (em. x 6.67) Males females Sexes Combined

OTOLITHS ·(cm· x .3o") Males Females .

· Se.xes Co~b i ned

.\

"\ log l = 1 1 0238 lpg S + 0~1405 1 og L = l • 0216 log s + o. 1499' log l ~ 1.0318 logS+ 0.·1327

log L = 1.2583 logS + · 0.62~8 log L = 1.}801 log$ .+ 0;7154 log L = 1:2280 log _S + 0.6513

\

·.

.L = 3.l153 ·S 0 " 97q~ · L. ; 3.3274 S 0~9479 .L = 3~1908 S 0 "~ 63 0

.. .. . 0.9"9 · o.9a .

0;99.

L = 1.3820 S l•D2.3S . · .. · 0.99 • 0

·L = 1 .4122 'S 1.:02.16 0;98 . l = 1.3574 S i·o3ia · 0,99 ·· .

. i

L = 472053 S .1 f2-5~ 3 - .

L = 5.1928'S l ' tBOl L • 4;480~5, 1•2280

o;g~

o. gy_ 0.76

' .

~ ..........:__ .

.......

,· -

.. . . . . .· .

. ~- - · - -~-_ .. ... ..J~~ .. :..~ .... :t~~ ... i;;'@t'n('iWr'lf7fr_1'.

f .

. • . • .. · ).l-ot .

..

.-,·.

: }

·.

~ _~_ i .._, T :

I .

0

; -

( .. ~ .,

. ' i

\ . ' I

..:.._..---:-'-----..~-----·-------·-- ~· .. -- .. : .. - ... ------~-:: ... ·:: .

/'

~ _; ..

t.-- ··.

~ - ·

"-' ·· ~ .

0

· '

r ... ·. . "- . ·. ~

·. '

' ' .

.. Tab1e 6.· · Empirical and back-calculated average fork lengths (em), using 'scales, of the different age-groups .

· _of northern pike fromJ Lobstick • . Labrador." . · · · · · · · -· .

' Age · · Fork Leng..t hs (em) (years) · Males - · Femaies CombiJJed

~pi_ric":1 . Back- Emp1 rica 1- _Back-Sample ca 1 c. : ·· .sample -·cal c.

Empiri ta l · . Back-.·. Sample c a 1-c· • .

· .. Mean Range - . Size Mean ·Range Size Mean Range Si ze 1\ •

ti

9;-9.~ 6 .• 1 9.5 - 2 •. 15.7 10 . 7 ~ - 1 ·- 13.4 ~

0 '22.8 .2 - 0 25".0

9.9 . - 9.3-10.7 3 14.8

- 0 <•_ 24-.2 -· 3 27.5 1 34.3 { 0 32 .. 2 . :.

. '4 . 43.3 ' l 41.6 0 .40.8 27.5

,. 33.6

.43.3 1 . : 41.5 :

5 46.3 40.0-52.5 2 \ 47.9 40.2 35.-5.:.46 .• 4 .6 47.8 41."7 35.5-52.5 8 · 48. 1 6 . SO.CF 31.2-65.6 . n 51 ', 5 47 . 0 37.0-59,0 ·n . 5'5, 6 -,.

7 56.4 37.0-66.5 '29 ss:3 60.1 46. 0- 77. 0 . - 18 ):;6d. g-

8 56.4 41.7-67. 0 . 14 ?7 . 9 64.7 53. 4-74 ._2 . 23 q5. 2

-48.5 31.2-65.6 22 . . 53.5

-· . 57.8' -. 37.0-77.0 47 ·58.0 : r: .

61 . 5 4 1 ~ 7- 74. 2 . · 37 . 61. 4 .

9 63.7 ~_M.Q .. 75.0 . 29 61.4 . 67.5 ·- 49.5-73.5 15 ~ 68.2 65.0 '44. 0·'75. 0 '

44 64~ 5. 67 . -.2 - 57. 5 -:.74 ~ 3 13 . ' -

10 63.4 72.5 55.0-80 . 8 19 71.7 -11 57.8 52,0-78,0 5 66 .• 4 76.8 . 62,5-84,0 .. 6 73.0

. 70.4- 5~ . 0-80 .8 . i

32 . 67.6 . 72.7 52.0-84 .o 11 69. 7 -.

,. , \ · _s·o.-o 12 - . 69.5 , 71. 1 . 77 •. 0-82.4 4 74.0 73.1

• .': 82.1 13 =- 1 74 . 8 ' . - ~ "' - ' 0 '·

.. 71. 9 ·- 77 .9 69.5-82. 4./ ·S

73,1 1 76. 1

. 14 .0 - o· S4. 3 ... - 0 80. 4 15 - ·0 87.5 1 8 6 .6 . -87.5

_., ' - 82. 3_

<0 .

- · - · .. . ... ·- -.. . _ _ ...:.,.._.:_.. ... -- ·"!' •"":·:', J: .. .. ...... .. ___ ... _, __ ·- - - ' --- _-:=_

'i

' . . . -~ \ '

. ' I

-. . r

·!

I ' I

r-.>j col _J l i

. ~

1 J l l J

.f I ' .

. ' ., i.

.;

I

i '

·. ·. '·· ..

~ t

' :· •·

. , .. - :

: . t; . ,. ,_.

0. 0

/

..,. ,

J

.., ' f ! [ $

~ t . ~ .

~ l :

. f t i t

..

.·= .. ,;.-. ..•.

( £1 •.

·,

•. ~-

0

. I .

~ . ·----- ., ... -.· --~ .. -. ..... .:. .~:..... ... - \ : - ~# L '

..... a CJ , ._., ol 60.0 .= r •

+l · ' b.O .• / =. ' ~ 40.0 ,!4 . ~

·,

0 ; '

·~~ 20.0

'' '·.

'·

'·.

·--

I

/ .

·I

..

MALES

·•

I

BOD

so.o

• ··-· .. ·--·--. ~-- ... - - .. -··"~~-·--··-·- .. - ............ ..._.._ ,; _ _ .. #Oi o"':::

..

~ -29-

A· - ' . ·'

·I

12 /' .

SEXES COMBINED

4

" !

a· "'

" •,

• 0 ..

/

·• . t .,l '

. il'' . . •.

' I

-~ .

I .. ,.

I

. \

. • '

/ ,

·6:

I ' . .,

·r···-

. ' . .. . I . { ..

~ f I

."'

.. · : ·

' • • '. 1, 0 ' ~ •

. . 40.0

r; 9 • 1o: · . . .. .

20.0

• / I

i' ! :·

4 e . .. 12 .

.·Age (year~) ' · .. . I . ' . . . I . . .. _. . . .• Empi rica 1-,(sca t t~r: p 1 o ts and ran~es) arid (:a 1 cul ate~ (fitted curves ) average . -·1 engths (em) s using s·ca les ~

.of the . different' age;.groups of. nprthe.rn' pike _from .. , lobstick, labrador. · · · · . . . . . . ' • .

• c ~ · .... ' l '', li'

. '

(. ~ . I > \~

. . ·-.: :.

' I •

I.

. " /

.' ...

0 ! :

• 0 .

. ,. ' . . .

- ... -. - ---- "·: --·· .. :·· ---·--··· - - -.-.---------'----~ -. ~

' .~

. . ; -... · . . •. . ..- ·.

./ .

.. . .r.. - . ' . r:-• . . -. . -' . . .

~ • 0 ' · ..

··~ ' r • • . . L-,. _....,:.__,..., ,..,.;, '"'"""'' , __ ...... ,_, • .,...,i'CI'ir"''"""'' s -. • .,...., • ·7;·-....,.·~•--:-.._ _.:_, __ ..... . .

~ . . ' ,• ~ . •. .' . ·- . • . .... '

, · , - · J

\ - . , __

. .. 0 ll ~- .

. - . --- ., .... ~-- · ~-- ~ · -- -.- --.. .... ' -o-

- '

. ·,

.-·'

1 0

"· ~

' • . (1 .. • . • • • , _ • . • 0

} ·

_-_ I . -1-

.Table . . 7. - Emp.ir-ical and back.;.c'alculated ~average fork lengt-hs (crri), using. ORer_cula, of the-diffe·rent ~ · - _ · age-groups of northe-m)-·.pike from Lobsti"ck, .Labrador. · --. . . . . . . . "~.. . : . .

z · ,~· . <

.. . .

_Age . - . . • Q , Fcir-k Lengths"'~ ( em) (years) ·· -~·-_ -".,_;- -~- -:-:M~a 1::-e-s__;,_._,. ··-· :::-~ - _----:---. -'------;::_F,_.em--a-..1-es------------:::;c--om-rb:-;i~ne~d~----.·

-:_· ·. -:... ... '

.. .. :. 1

.f 1 - '

. ' < •

. - . . ' . '. ~

\ ,;

, ~mpi rica 1- . Bac~- ~- .·. Empiric~ 1. _ Back- ·• · Empi rica 1 0 . ·,Sample·-- cal~. · " ·. S~mple ; calc. . - Range ~; ze ~ _ -Me.an Range· • Size - -. . ·. .

. 1) .

.. ..1 · 2

-. I .

·2

·0 . 3 . . ' 33:~8· 27.5-:-40.'0 2 .

24.,7 -.3-3. 5

_-·41-·. 2'Y ' . ..... 0. ~- '

. -.4 39.a ,·31.2-43.3, .s·-. 47~5 .: §: so:2 . 41.7-57.5 17 -S2.9·

1.0. 7 1 26.3 ~t <;..

0 ·' Js:a 3 ' 43\6 .

' 41'( 5 ,. ~7:5-46.4 . ·' ·7 51.3

Mean , -Range

9. 9 . 9 • 3-9. 6 . .

.. , . ,· 6· ~7.2. ·?0.2-66 ~ 0 . _.25. - 57.~ '

48.5 ' 40.0-:_56.'5 60. 3 . :4S.. 5-:73 ~ 4

7

1~

"56 . 5

62·.2

37.6 27.5-48.0

40.8 31.2-46.4 .

49.7 40.0-.57.5

58.5 45.5-73.4 65.0 . 37.0-78.1 .

69.6 62.0-80.8 .

70.8 49.5-83.3

' i

I

' · .

. . 7 62.1 ' 37.0-71.3.-- 2'9 "" 62.0 . . .

a·· ··. 68.1- . ~63'.4-74.3 : 14 _ - 65.4

.67-.1 " 51.0-78.1 '. 39: ' 66.8 ..

77.1 62.0-80.8· .' 14 . 69.3 . . ·,. .

a: ·. 67. T ~ ·- '· 12.2 49 ~ 5-ai-. 3 -~- 9 ·-..

_.-_· 69. 1 _. ~ _64; •. 6-:-7S. o · 9 . 2~

71. 6

74-.0 ' .

10 ..

.11 12'· ~

l3 14

' .. , 5·

68. 6 65. () ... '71 -._ 4 ." • ..

73.6 69.7-78.0

-'

..

0

4 .·:·68.3 78:2 '74.0-82.4

.3 72.1 82.0 79.9-84.0 . "<

' 0 ~~

- .

0 ... ~ 80._5

0

\ 87 ~ 5 0 --

2 -77.5

.' 0 . . 76·. 2

.1 - --7.9 .·6

,o 86 •. 0

1 88·. 1

. - 71.8' 65.0-82.4

' 76.9 69.7~84.0

.· ·-80.5 .

87.5

. ' '~-' .

,,

· Back- :. Sample .c~lc.

Size .. ' . \

3 '" 25.5 .. 0 .34; 7

5 . 42.5

~12 49.5.

24 54.8 43 .--., 60.Q·

68 - 64.4

28 .6Z.6

J-7 ., 69.9.

6 I) 71 .~ 5 75.5··

0 76 :a -

l . 80.3

o. 86.9 89.0

- o

. J

: . r '

I j

l -. j \:: l i .

0 i ' ;

. ~ ~ J

' v

. i /o I .

! . ;. I i ! i

I

,.

. I

' .

·•.

;-

·~· ·

. i

;.•

\ i' J.

t . l !: f· t ! l. t i l t . . i

j ·.·J

·~ '

...... --,.-.. ...... -,.-·\--·-------.... ·-..... - . ---------- - ~·~ .. ~-~~·-.~~_;_'.'-";~ ~.: ~~;~~--~·~·--·-~-·-·---~ -----

/

·, '

.~.·

I .

· ...

. •

·t·

•,

-.=·

. ..-a bJ) s=

-.

..

~ - 40-0

~ ,Joe 0 ~ -

·20.0

' .

: : i

. MALES

• •.

. ......

-I

, •

/ .• ~~·

311

.. \

' ·. .. ,.

.. , . '

\

,. SEXEs·-cor1BINED . . . .

60.0 I

40~0

...

.. -·' .

• ' 0

F-EMALES~~ • ..... -·?'",..- . ,,

\ · I

f· !

. ·~ . I • \

.· .. •'.

,i .

I \.

/".

.. .....

·, .

• I

..

.. ... · I

; • I ' I 1 ~·,; .. ..-# ...

. . ~ ....... ...!..-

J '

l .

·. ' . ·

· ..

/

''

··.

\. : .. . 1,· •. ' •.

. . \ I

'· 20.0 I

. " " ' I

• .

! I

I .

• • . . .. ,

_.r' ' .. I

. I I

I ·.

. Fig., ll.

! '

"

' '

/ . .4 8 12 i ·\ . · ·~ge (-ye~rs L _ ', . . .

- . ' f • ' o • • ' \t ~ 1', \ :' I

· 'Ern~ir.i~al (scatter plots an~ rahges}. and.ca·lculate·d · · (htted curves)· average ·ler,gths (em), us1ng opercula~ ·of'.-:the di ffe~nt age-groups of rior.t~ern _pike from '-

... Lob.~tick,' Labrador. .. · . . · · -

···' •. 'I'

I

I

4 ' .\

··. -.

.. , ~ -~·---~~ .··.t;t '.

L

·• ··:

l • t .H

' I . I !

,. ·'

.• ' .

....

- ..

. . •

'-

. !

•' . .... ~

: i ._. il

l ' ~

· .~ ·-· 'i

. j

-, ... , .... .· .

... : .

.~

\ . - '

i I· .

. ·• .~ ,. ·,

/ . .. .~ ,·; :.t . ..

·J. ...... .

. ·: i I. •I

.-, )

. " ·< ·

I .

. '·

• ·

-.

; •,1

I ' . ' -· ·. • '

.-,

i-• . • ..,.. __ ____ .,..,,_.;.. _____ ,...-.. --,_..,..,_ ,__ ....... -. ..,......_,___.......,.~---c-~·-w------· · ••-·---- ,._ , . . ... . ...... -. ~""'·•-;

I

' -

_, -:

- 0

Tabl'e at. _Empjrical and ba~k-car~u!ated average fork ieng~ -(cm), using_cl--eithra, of the- , different~ ..., - age-groups -of _ nor~hern :ln ke from Lobs t1 ck, Labrador. · · _ · t

Age (years) Males·

Empirical

Range Sample Size

Back­cal c. __

Mean

Fork Lengths (em)

Females Empirical

Range

B'ack­Sample calc. Size

Combined Em pi rica 1

, __ Mean-Sample

Range Size

Bad<­calc w

2- 17 ;4 ' 10.7 ' 1· 18.1 -- 9.9 9.3-10.7 "3 : 17.6

--

· i

~. 2 - 3

4 -5

6

7 - 8 -

9

10

11

12

13 14 15'

., -·

.;. ..-.•_..--,. ,.•,, ,.;:, ro .• ••• ' • -

r-

27.5 39.7 31.2-43.3

- 48.3 40.5-55.5 58.1 50.5.;.66.0 61.1 . 48.0-75.0

0 28. g·

1- 37.6

5 44.9

14 51.0 34 56.3

-25 60.3

~68.6 " "64.3-74.3 -12 64.0 68.0_ 61.0-72.0 --- 8 '. 65.8

- 68~6 65.0-71.4 - ~ 67.4

7.8.0 - ' 1 68.8

73.1 ' 1 64.2

0

0 . .-

- 0

35.5

43.5 - 37.5-50.5

-:47.2 39.5-56.5

58.3 37.0-72.0

66.5 51.0-77.0

. 70 1 3 62 ; 0-80. 8

72.1 49.5-80.5

72.2 55.3-84.0

82-.9 82.4-83.3

-·' ....

87. 5 )

· '

0. 29·:·3

1 3"8.5

4 46.3

l1 - 52.5-

19.- sa:s 29 63.6

18 , 66.7

' 12 69.6

5 . - 73.0

2 76.9 -

0 77..3

· · 1 8L2

0 - 86~ 3

1 92.6

~-

· . - ... : - -....... . . ··' ....... -· - ' : ... ..:. ·.- -··---- ·;...: .. ·- ... ~ - -·- ·- · ; .

~1.5 27.5-35.5

41.4 \ 31.2-50.5

47.8"' 39.5-:-56'.5

58.1 37'.0-72.0

64.0 . 48.0-77.0

69. 6 62. 0-8o-.-8·

70. 5 49 . 5-80. 5

:70.-2 55.3-84.0 1

: ~~ 81.2 78.0-83.3

73.1

. 80.5

-87.5

0

2

9

25

51 54

. 30

20

11

3

1

1 0 _1

29.0 -38. 1

45.7

. 51.9

57.7

62. 4

65.9

68.2

70.8

74. 5

_73.2

81.2 -

86..4

92.8

----,-----+-

w N

-·

. ! .... .

. !

! ' ~ j )

-' 1 . i .

! . i

- ' I

. ! ~ -' . I ; t

! ·I'

lv 1'

· J . \

I ! I

! .j ' \

I • I i ! ;

--~

. '

. . . .. ~ ...... ":'~~ ....... - ._. ... ~: ___ : ...... ""' ~~~-.--:-.. ~----:_:.._~-, -- . 0

---·-~---. - ----- .

·._.... .

a .0 ~

.= ..., ~

= C) ...... .!at ;:.. 0 ~

-~. : I

' I I'• ,..

, I .. '

' I f

.:I .f [

/ I

I l-f, ' • }

' '

\ . ' '

I . :

' .. I

, . ,.. '0

" '

80.0

so.o

40.0

...

I·

' 33, ·- ;-

MALES : · · FEMALES

/ ,

\.

"! ' , •

• • /

... .-. .e

I '

SEXES COt-lB I~ED acto

• ... 60.0 ·, .

' 40.0 f. '

' ··--. • . .,.·.

' f

. ' . . Age · (year~)

/

· Fig~ 12. Empirical (scatter plots and ranges) a~d - ~alcul~ted (fitted .curves) average"l.engths (em); using cleithra~ . of the different age-groups of north.ern pike from ~obstick, Labrador.' ·

.• . .

- .·.

' . I t ,.

. ' . \ .

.. l . \ .

!• .·,, .· .•

I I

l 1 .

·' ' ' :

•.'

.....

- -,

·-

Table 9. - Empir_ical and back-calcula-ted ave.rage fori< len-gths (em), using-otoliths~ of the different age-groups ·of northern pil<e from Lob~tJ c~, Labrador.

\ · ·· .. , .

I'

~ • I

' ' '

j '

' '

I

. , l

' ' j

•,

I

'•

.•

" '

80.0

- .. e:. 0 / -/

· ,.t( 60.0· .

~ -Ql) "

=· Q) 11""4 40.0 ~-

J-1 o . ~

20.0

..,.

. .

I"" / "

. I .

i .

- _, ____ ., __ ...... ~~-.. _,..._ ., ...... ......._... ____ . __ " _____ .:~--

.- 35.

~1ALES , . . . \"

·FEt1ALES . I ,

··. -

/

\ '

•• ' · •

' 4

\ . \

S~XjS .COt-18 I f~ED · ' ·

. 80~0 . I

so.o

·. ' '40~

.6 ..

-. .

. 20,0

• , .

4 8 12

Ag~ . (years_)

ll' . ' ' ' • ...

I ., .

.. \ ·, . ' .

I ' , I •

Empirical (s.catter P.lots ·and ranges) : .. and c~l .c~lated (fitted curves) average lengths (em), . using ot~liths, of the di ffererit; age- gro.ups of northern pi ~e from

· Lobstick, . Labrado.r. "'.

. , ( ·-

. ..

·'

., ~

/ . ~' ., ~ ,·:

"I

' :1,

:~·

"

J ~~

., i

' -! ' i

I J

n . l ·,. I

'

I .

I i·

~ ~

.. i

i I

I

I t . !

,.. Table 10. Summary of results' of 'co_variance _analyses for empirical -arid back-calculated age-l ength regressions,

males vs. females, of northern _pike fro·m Lobstick, Labrador (p = 0.05_; significant difference • ihdicated _by '*'"). . ,

Method of Aging ·

Scales .·.

'Empirical- · Back-ca 1 cul a: ted

·, .

Mean s9·uares ~~-:-----.i-----:-- \. Within Regression Samp 1 es .Coef_fi ci ents

.001419 .'000070

.000735 ,'007998

Mean Squares Adjusted · · ·. Slope ·. Common Adjusted .!,1,:.~ns _. ·

F . · ·p . . Regression Means _, _ .~ F . P ~ .~ ;

0.05 0.822 ·.001329 .002788 2.10 . 6.165 10.88 0.004* •• 001051 · .001'234 1 • 1 7 ' · 0. 290

·] Opercula E'mpirical · · · .003278 . . 000058 0.02 0.891 ' .003088 • 006607 2. t4 . 0.159 ' .000099

·\.

!J

' .

~

• '

Back-calculated

Clei thra ·. Empirical ~ . . Back-ca 1 cul a '!:ed

Otoliths . Empirical Back-c_a 1 cu1 a ted

.000104

.. 002217 .000914.

.001986

.001675 .

·-

;·ooo·oo6 0.06 •,

; 001122' .0. 51 . . 000927 1.01

· .Oo'0002 0 \00 ·.000490 0.46

-! ' :

~

. I

' .

. '

. 0.811 . . · ~004842 ' 48. _85 <0·.001*

0 . 507 - .002153 .004969 2.31 0.144 0.32? .000915 . ~ 003878 4.24 0.04~~:.

. O.QTl · . . 001854 .003770 · 2.03 0.172 ; 0.512 -':'"001040 .011229 10.80 0.004*

"

''\

_ ...

·. , . . . . . \.

'."")

·. bJ . 0\

_ . . i ... ''

. ! . ~ I .. l I

·l ~ - .i

, I

l !

. f.

• • • I •

• 0

' ..

. . Table· li.

.,

. -' ' '

Surnnary.of results of covarianc;e analyses . for age-length reg-ressions (sexes combined and separated), empirical vs . . back-calcu1ated, of northern pike from .Lobstick, . Labrador (p _= 0.05; significant difference indicated by·~·). ~ -. .

.' \.

·. Mean Squares

With1n Regres~ion . Slope . · ·. - Mean ·Squares

Common Adjusted' Adjusted · · ~1eans .·" ·

Method of Aging. Samples- . Coe!ficients F P . ....:. . Regressj on Means F p

· Scales

. Opercula.

.. · Cl ei thra

; ...

__ Otoi i ths

·Males Females, Sexes Combi-ned

Males Females Sexes Combined

Males · Females se~S. Cornbin.ed

Male·s Females Sexes Combined

. 001981

.001089 .. 001468

.001.754 . -.

.0.02415

.002259 I

. 002251 · - : 001944

.002061

~OQ2444 .001397 .~QJ r7_1

.018885 ~ 006472 . ' . 015513. ' .. .067087' ·.057054

9.53 0.006* 5.94 0.025*

10.57 - ' 0.004*

38.24 <0.001* . ''23 .. 63' . <0'.001*

.. 058289 . - 2s.ao ·<o ;oo1* I

.042907

.018139

.024871

. 00136(

.001967 .. 001439 .

\

19.06 0.001* 9. 33 0.006*·

. 12.07 ~ 0'.002*

.·0.56 . 0. 530- . 1.41 - · 0.250 o.8i o.619.

·· ·-· . - -.... ~ ~ ... ~ .. .: - -- - ~-· ··· . _. ___ ,_ .:._.:_ .. -....... .. - --

J.

. 002786 .

.001406

.Q0207-9

. . 003669 . . . 001887 ... . 002944~- .

~005597 .015864 .·ooso16 . - . 01 022s .004927 .013726

.004390 ~00l716

·.003053 '

.002387

.001427

.001757

' .

.0039l3 ,·

.003298

.OCT4853

.000484

.000306

.000215

'\

1.32 0 . 263 . 1.34 - 0.262 -1.42 ' 0 •. 245 . . 2.83 0 . 107

.2 ... 04 0.165 · 2. 79 .:· 0.107

0.89 .0 : 641 \•

1. 21 0.283 1.59 0 .'218

0.20 .• o.-66l 0. 21 0.653

·o~12 0. 729

..

. ·,

'

·' (

-. . I '

I . l W " ! 'I · - i

' ;

\ I.

- ·1 -

i

\ . .

· .. -.

., ... ·! .

(-

. f1

' .. .... -.~ -- -.

( --0

:... .

(i • -

;. - ~

Table '12. Sumniary =of.. results of cova'riance-an~1yses· for emp-irical and back-calculated age-length regressions (sexes contiined and ~eparated), scales vs: opercula •vs. cleithra vs . otol iths, of northern pi_l<e from _Lobstick;Labrador ·(p = 0.05; sigriJfica~t differenc·e indicated· by · ~ ·) _.

I

Mean Squares ~ • Mean Squares Adj~sted rteans F p

Slope Within ·oRegression Samples Coefficients

Common Adjusted Regression Means F p

.-

-1.01 0.403 1:7}. 0.176 1.4 - -0 .. 231 -

\ Empirical Males -.002898 . 000626 • 0.2~ 0.885 . 00_2704., ' .002719

-Females ,;002409 .000063 . .I 0.()3 OA94 . 002181' .003822 Sexes Combined .003047 I .000114 0 . 04 . -0.-990 .002821 · .004210 .

I '\ . f

11.82 <0.001-* " 8.83 <0.001*

14;00 .<0~001*

-Back-. Males .. 000623 . . 016'496 . 26.49 <0.001* . _.001844· .021795 ca 1 cu·l a ted Females .000597 ' ·. 021449 35.90 . <0. _001 * ;001735 .015325

Sexes Combined .000544 .'018767 34.51. <0.001 *· . .001538. ·.021535 \

' .. ... '.

- -

·' ,.

:,-· ''ff -

; .· .. ,I

... .... .

\• ·--- '

• .. · - ·- , - · .. - - _,_.. ·• -.. : -·-· ,._,,:.. ....... ~ ... (~~ .: .... :. ·.:. - :_ .. _, -<. ~: ;.,., •. .__ •• ~ ..... ·-~-...:-~~ ..... ...... . ··- ·-~-~ · ., : , ..... -. ... ·-~ ....... -.,.-........... ... ·.}...:;.,(L•i. ~~f.;·Sc_. L.~l.?;/Si ' '? : y ··

·-· '

"

'

·. .• t w ' ~ ;

:v "CXl. ' j

I ·- ! . ~

-.. -"\ i

:,. i ' 1

-1

'\

1"' .• I

1-,

.. .

. -·=·

_, .

Table 13. Surrmary ·of results of co·variance analyses for back-calculated age-length regressions (sexes co~bined - and separated}, .otoliths vs; scales, otoliths vs~ cleithra, otoliths . vs. opercula, .-scales vs. opercula,

scales vs. cleithra,. and opercula vs. cleithra· of northern pike from . lobstick, Labrador (p = 0.05; ·. · significant difference - indica ted by ·, * ' ) . · · · .

. . ' "

Otolit~s vs. Sea-les ·Males Females

• ' Sexes Combined

OtolithS vs. Clei thra ·Males Females ·sexes Combined

Oto 1 i ths vs. ·Opercula Males Females

· Sexes Combined

Saal es . vs. Opercula -- Males ~·

Females Sexes Combined

-Scales vs. Cl ei thra Males

Females· Sexes Combined

·;.~. op~rcula vs. Cleithra ~Males

. . .

.· -.in-. : ""~ ~ . . .":'

,F:emal es Sexes Combined

. ' .

Mean Sguares

Wi th:in ~gression· Slope·

.. Samples Co fficients F p

.000824 .013558 1'6.44 0 . 001*

.000869 . .000012 0.01 o. 902 .

.000746 .006945 9. 31 o'.005* - .. 018205'. ' .000878 . 20.74 <0.001*

... :ooo616 .010194 . 16.54 . 0.001* .000696 .015849,. 22'. 77- <D. 001 *

. . 000557 .048q72 87.34 <0.001* .000493- . . 048220 97.73 <0.001* .000463 . . 054211 - 11 7. 21 <0. 001 *' ..... $

.000368 .·010854 29. 52 <0. 001 * . ~ .000579. .010467 80.72 <0.001* • 000391 • 022350 - 57.09' <0.001* ..

.000688 ' .000342 o. sot o. so4 ·

.·000701 . ,009501 1 3. 54 . 0. OQl * .. 000625 ~001811 2.90 0.097

. 000421 .007343 17 .45_ 0.001* • 000326 . 014071 .. 43.i2 <0.001* .000342 . 011436 ,33.48 0.001*'

' .i

-..

. I

Mean Sguares Adjusted .

Common -A9justed . fwleans ·· ·

Regression Means F p· .

.001946 • .006126 4.10 0.055

.000837 . . 000001 0.00 0.967

. 000976 . . 003142 3·. 22 0.081

.001790 .026730 14.94 _0.00~ *

. 000971 - . . 010550 10.86 0.00·3*

.001257 . . 025052 19.93 '<0.001*

.• 003090 . 058121 1 ~~ 81 O.OCT1* . 002261 .032701 1'4. 4'6 0.001* .002453 .053990 22.01 <0.001.* .

.000920 .026508 28. 83, <0. 001 *

.00'2287- .032282 . 14;12 ' 0.001*

.001205 . .031085 25. ~0 <0.001* \_

.000670 . ': 0072~3 10.84 - Q.004* ·• 001274 .Ol03f3 ·10.04 0.004* .. 000669 .010045 -15.62 0.001 *

..

.:_ .000785 .006020 7.67 O.OlZ* . . 000835 .006103 7. 31 0.011 .. .000753 .005488 7.29 0·.011 *

. . -·

\

, ·

,.

~\! ·· lO . i I ' ~ . . \h

. . 0

1 . ~

' '\ .-.. . '

. ~

..

; . .

' .,.

I. ' . '

. ~· ' '

•. ~

'

. \

. . · ( ·'

..,··.

' ·.

~ ·. I

' . /' .

I ; '

. . I.: I . ··/ . -.

. I: · / . i -

/ · ;

~ l. ·.

' I . i

-.

I

1 t ·

.·. \

I

·. '

'I

. . • • - - ··::-----·- ~ ._.._ ....................... , ........ -r-.,., ~ ..... <.-:•-T"r>:•<" -•· .. . - ...... . .......... ! .. - ··-: .... · ~.--·· -·

"' 40 - · . '.

...! • ,

Table 14 . . . Length distrjbution of northe~n pike . from Lobstick fQ,!' · ~ 1 sexes combined ~nd sexes sep-arated .(sample size in ·.

· · 'A parenthesis). · ' . Percent~ge. of fish in each length class

Length class (cf!l) -. Males

,. 0; 0- 4.9 5.·0- 9. 9 . 1 .l (2)

10.0-14' •. 9 '

. 15.0-19 . 9 ·' . . 20~ 0.:.24~ 9 . ·'.·

25.0-29·.9 0.5 (1) . _30.0-34.9 . 0.5 (1) 35~ 0-39.9 .. 0.5 (1) .

"40.0-44.9 6. 3 (12') 45.0.:.49.9 . ·5 . 3 (1 0) 50. 0-.54.9 13'; 7' (26) 55.0-59 . 9 20.5 (39) 60.0-64. g. . ·18.4 (35) 65.0-69 . 9. .. 22.1 (42) 70.0- 74.9 10.0 (19) 75. 0-79.9 1.1 . (2) . 8'0. 0- 84 . 9 . 85.0- 89.9 I

~ - · ' . Total s lOO ·. (190)

Mea.n l'engt h 59.3

Range '9; 3-78.0

.. Std~ dev. 10; 34 .

Std. ~rror · . . 0. 75

' . \

·.

' >- ~ \~·.

... -- ,.~ . . .

• ' ·. ' ..

'I

Females . Sexes Combined

0.4 (l)

r . 0.5 ' (2)

0.2 (.1} {1 '

"

0.2 (1 ) \ - / 0.2 '(l') ... .

2.7 (6) ' 1).

1.7 (7) 3.6 (8} . . 4.8 (20) 5.3 ' (12 ).' · 5.3 (22) . 7. 6 (17) 10.4 ( 43 )• .

1 0.2· (23) 14.9 (62) 14.2 (32) 16.2 (67) . 22.2 (50) 22.2 (92) '.· 17.8 . (40~ 14.2 (59) 10. 2 (23 6.0 (25) 4.9 (11) 2: 7 (-11 ) 0.9 ( 2) . 0.5 (2)

' 100 (225) 100 (415)':

. ' 64. 3 62.0

. 10.7-'87 . 5 . l

9. 3-87. 5

11 . 51 11 ' 26

0. 77 0. 55

. ,.

' ' '. ·, , I ..,

\ · , : •

I .

/

'·

, .

' ---

\ ~. '

· , \ .·

• ' .'""' I I . • I . ,._ ,~. ~ · ; · · ~ ~ -. _. , .. ... -........ _...,.. ..... ,_ .... ~_-.......... ... ______ · -- - -: .. ~ . - . -· ____ .............. - "PV'''" ""Il''"' ...... : ,,..... . ._......,.""1:'7,--,.- .., __ , ........... ,_ ____ ..,._. ...... ...... ..... ~ .. - .... . . . .. -..

I •

. . I

. ,"" .

·. \ o. I

' ! ·' . '

,. ; .

' ·! ' I , <1 > ;.· I

..

.; ' I

41 ; I

I ./ -

. . ' ! . -. . .

.

I / ~

r ·. • I . -. . . . . ··majority of fish (78%) bet\'1een ' 50 and 75 em. · -Males and females

('I ' / • ' I

.show.edd1ffererit .. length .distributions, femal~s growing -longer · · . . . . . . . .

than mafes. The .average length of males ·and -females differed · ~ . . '

significantly (t; 4.50, d.f. · ~ 413, p < 0.001) •. .. .

A .. conv~rsion factor for :fork i~ngth to ,. total' -l~~th was · . _

- . calculate~~- .fork length = ·0.94 total length. . ' I , ' •

2. Weight · ·: '·•

·. - . . ' . / . I .Similar to 'the length distribution, the total weight . •.

• ' ' • . . b •

diS'tr.i-b~ti·o~- 'is unimodal (Table 15). ·. F~r-· males, . 43% of_ the fish . : ,· . . -.

wei gtle'd. be~een 1. 00 and 2·. 00 kg; . for . f~ina 1 es. 36% weighed . . ·,. ' . ' ' . ' . , '

betw~~ti 2.00 and. 3.00 -kg: · The he~vi'est fish collected .were . .

:females'; mcdes and .fem~les 'differed si.9nifica~t1y 'in ave~~ge

_. we.ight. (t= 5.13, d.f. =.-4'13, p < 0.001}!. , I

'·

~ ' ' ~

I

/ ' -. · .. \

.. ' _,

. 0

. '

. Age composition, as detemined _from~otoliths, ranged ' . . .. _./ . . - . ' . . '

. ·. : .- ·from 1 t9 1'5~ with 56% in the 7~9- age-clas~·es (Tab_le_ J6). As . I

· .... . with -length1lnd wei ·ght di~tributions, '.females tended to b'e older

--- .- •~:-~~ttHm-mal~s;. the oldes .. i m~e sam~led'was 12 and ~he· oldest f~mal~ / . .15. . ., .. ,\' . . . \ . . . ; . ;.·.

I •

l ~ . , ..-:-

- ~

j ·B. ·Growth

1. Length:..weight relationship· I .

. · .J

> .

\ ' ' . . . .. The· length-weight regressions f~r . males · and femal.e~ (Table 17) .

: o I ' •

i y'

•"

,_·

l 4

! l ! .

·! ., . ·-: : ; ~~

.s I '

·i · • j , . : . ___}---:-

· \: ~:f

---~- _·.· .. .I ,I: . -..d

.J

(

! '

{ ·.

. .·.' __ di_fferent signifi~aritJy (F.= 16.~9·, ·d. f. = 1,410_, p < 0~001')~ There ' ' '

was. golod correlation ·between iength and \'leigh'( (r"'= 0.98 f~r ~ies.~ : . . · . . .

\ .

, . . .-.· . · ~.-

•. ' ' ' • • I ~ ;;

.. '. \' ' . :. , .'.· ' . ' . . . '··_- ... ~ .... - --.-... -:-· . ·--:-·--.. --;-,-:-.... -~---· . _ _... .... _ ~"'":---· --~.--- , ·, ·,.1: •• ~-r· : .. .... .

' .

I

, ..

1

.:.,

-... ·. ~ ........ ~ ... --........ ---··--·;.-·• - --: ~·? •' ·--: ·;l-·•·p·--· --·~ - ·'1'·•·· ......... - .. . ,: . ~ - - ~ ........ -~---;-... ---~; .. __ _.;.:..~ .... .--.. • .._:...... j- .... .... ~~ ...... : .......... ~.- ,..~- -----~--. • --~- .•• / •' <

'. ··

. ~ -. . . . · . ..

' ~ . ·' ·-

r . . . ·

.. : i

;. \ .

. '

. ...

:~ ': •

( 1·

- 'L I

··-t

,, l·-

·:! ~ . I

i:; ( . I h I t ·'· ; ,. \ ; l '.

, , )

i i

I ·. I l i I

.

! (

! ~

\ .L :

I

. . ,

, ; ' :·

' .

· "' I .

42 -' /

- ..:1 ~ . . "· I.

I .

r = CQ.99 for-fem.ales). . . . . . .

The exponent values for b'oth sexes were t

'close to: 3; .for males ri = 2.96~ for females n =· 3.1-a .. . . ' ' ; :.· The mean w~ights .calculated (using 'the COmPUted length-wei.ght .

' . \ ,·. . . . ' ' : . .. . . . equations) .for the mean leng.ths of· fish .. i~ each length ·_group are

the bases for 'the. c.urves .in Fig. 14 • . Thet'e ~as . good aQr~ement ·. · ' I ' . • t ' ' ,

. b~~ the empit:"ica) ~nd ca~ciJl.ated weights .for the sexes sepa:r.ated . / . . . ' ' ' . . .

a~d ~ombined (Tab1~ 18}. Minor. dis·crepancies _occurred.- at the . e~treme?; : .' '. ' . . ' . . .

.• . in the smaller and larger length 'classes, . wh~re ' the number of .. fish : l . ...

· sampl~d was small. , f ...

,"i

, \

. 2. Length distribution··of age groups · ..• ·, .

~--- . , ' ' ~

-~--. The length 'distributfon of a·ge group5 (Ta~le 9 and Fi·g. 13) I •

shows an ove.rlap jn length between age groups, especially in the. e .. , .-•t ••... .

:'

6710 age grG-Yps ·:where sample sizes a.re larg~r·.· The ove.rlaP.· is ' . . . . . ... . . " ~ .

greatest .for. 8~year-ol .d males,- ~hi.ch .ran.ge. from 41.-7 t~O ·em , : ' ' • \ , ' \; ':' . . ,.

a~~d for. 7-year:..:old. ·females·~ which range fro.m 3T. 5· to n'.o em.

Compaf'f~ns .of no~thern . pike growth rates ' fr9m four ·areas :·of· Labrador ' . .. '

I ;:

are _ giv~n~ in Table ll . Si nce Br-~~~ (1~74, 197Sf.and Parson~ (197S} '. .. '

use,if scales. for age. deter~jnati~n, ·age-length data. usi~g both cS~~les

and otoliths . have been in.cluded' i~ this comparison: .. . . - ' .

~-

. ,. .. , ), ,· _,_..,

. 3. Hei,ght distribution O'f ·age g.roi.Jps .- . . ' .

Empirical apcl calculated age-weight data are· given in Tahie 20 ' ' , o .' • ' I -o ' • • I \ , ; ' < ' '

an~ Fig.lS. ·_.· The .calculated· weights wer~ :obtained ~?om .th~(ien~th- . ·. ' '• ': •

1

D "' • • ' r , • • " ' .. • ' · , • • •

. . . weight relatiqnship!. using the back-calculated leng~hs .for each . ./ . . .. . . . .- . . ' . . . ' . . . . - ' . .. . · . .

age group.· ,The· cu·rves ·in Fig. 15 a're graptii!= representations . o~. }he·;;: : ., . !!,.' · ~ · .... ' · / ·,y-:-

.. '\.

.. . '

~ 0 ,' .. ' ..

. ·-·. ' . .

I . - .• • ·- ~ • . !

.I . , \

I . J ·_ .· l· .,..

'! • _r_'.:· . ..,

l

£ . ~

. {~

' ·; - ' , I !

i . !

d l .· : : Q t ;

. · ~

' ..

, .... .. .

' : \

. . ·.( . . I '1 ·i

'.j . . '

·'

' .

· .'

.. . \

'

~ __ ... _ -·

' '- , ' I .

·- ...... ,~, ... - ,.._-... -. ---...:::~ · ·- · ··---~-. ... ~-.• V.. .... - ...... - ~-.. , ... ,_,, .. ,_ ... _- -·-.. -- ·<~.· --·: __ __ :._ - ,'

·.· ~ .... · :r~ ........... _ ___ . ------------.. ·--.

I ' . -·· l o. . ... ~ 43 - '

. . , . ·'

'•

' · . , .....

- ~. Ct

·Table ·1s.' . We1ght distribution of northern pike fro·m lobstick for .. ;~ sexes combined and'sexes s~arated (sample size in -~

. . .

'I • '

· ... ..

·parenthesis). .. r:J / · ·'

. /

c: . ' . . . . . o ;,, ·w · -~t 1 • · ' ·! !0!1 g c ass .

'. ' kg) ... . . . ~ .. . / .

0.00-0.49 ,0.50-0. 99_ .. 1.00-1.49 ·. ,·.5o-1. 99 2.00-:2.49 ' 2 ~ 50-2. 9.9

" 3~ 00-3. 49 .. . · . . 3.50-3 . 99

I

~ Pe'rcent age or flsh· in. each · .we{gh~ :cl,as~· ·: ~les F~males · Sexes _Combined ,.

s.8 (11) . s.4 ,·(12j· ·. · ". s .-~ (23j. 12.1 {23) '8.9 (20 ' 10.4 (43 21.6 (41) 13~3 ·· {30.. ·, 1~.1' (71 21.6. '(41) 13."8 (31) .· : )7.4 . (72) · '

. 19·.5 . (37). 18.2 {41) 18.8 '{,78)•

. 14'.7 · (28) _· ' .. _17.·3 (39)'• 16~1 : - {67) . · 4.2 . <e> ,~ 11.6 (26.) a : 2 .. . (34)·; 0.5 (l) ' 5.8 ('13) . 3.4 (14)

. J!fj' _. 4.00~4.49 . ~ 4.50-4.99 ,( . 5.00-5-..49

2.2 ·,: ;(5) 1.2 (5) 2.2 . (5) ' 1.2 {5)

. ,

, To~a1s \ '

., '

.... ' _c . · ·' -. Mean. weight

. ' ' ' .

. • .

I p

. ,

.• · .;--~ .

' · r I . . i

·:-~ .

\'' .

·'.

.. Range

· · Std ~· dev.

Stp~ ~rror

·,

. ~ .

. f1

. )

100 . (1, 90)

l. 72 ' !

0.01-3.68

. 0. 7]. '.

0 . 06

' ( '

~ . . \ .

. · . ~ ~

-. ~ ..

'· . ... . . . . . '

. ·-

,, '

• f •

- ---'-··_,_,, ___,~·., · .. ------- ~

L3' (3)', ._.0.7 (3) . .

100 {225) ' 100 · (415) ' '

" 1--

2.22 1.99

0 .. 01:-5.30 0 . 01 -:5~30

1.10. 0,.99 '

0.07 . 0.05 ...

. r

t · . . . . ...

· ' ' ...

"·· .

. .

' ' ·'

~ . . ' ..

. .. ·. ,.

. ' . - ·'- -

.. I .

·~

I • ' · ' .... ·. - - --·r.:- -- - · ·. 1

.·,·.

. . . . i '

: . ) J.,_ .

,, .

./

:•. ' .,

.. / '

. .

. f . .J . ' < ·,

. : 1. . . . cr

. 'i' . ' ~ . J· . ..... _ ...

,. ~ . , --

. . . ~ ;, .. J-'' . ~ ' ' ' ' ~ ' I •. ~ : \ . .

I ·. v·. • .

1 ,o

I ;

· !

·' '

·I ,

I I .

! ,: .

c L , . . ,• , ' "1

~ ··· .. . I . . . ·. . . ... -:-. \.. \ ... 0 • r \ 0 0 > I ;_~ 0 -0 :, . • .. , '", • •

' f :· • ~~ ...... ,.,--~-,........_..._ ......... ___ --:--....;......-

·~ .. ~-~~ ~- ~- . .. ' ... '.. .- . ·" . ' . ··. ··- . ·: .... . '

' ' ':I .:

~' • I .~ ~. . ' . ,. ' · • . I , . ' . oL"<"".t_. 1 •

~ ~-- .· '~ : .. ~: : . . · . . -_; ...... ;:; ... ' . :- D • ._: ,.

~.-. •, . ' ' ~ "' . .

• l

·! -~ - . ' !: . ·'

• •-o::J ' ~ ' · ..

• ~ · ,/ : ,: • I

I • • , • •

. ·. - . .. " " . ~ . . ... . .. . . . ' \ ' ~ " • ·,. ' ' • • I I

, I, f ' '·. · .. ·.' .. · •, ,._ ·,. '! .. : ... ·. •'

.. :~ . ·' . :. . ' · .. ~ . . ~ . \. .

" . • ' .. ,·

..:. 44 - . , . . ' o I '

.. . ., . •

• ,1 ·· . I; '

. ... • . ,· I . _:'

·' . . ·. • . r•:,

.:: ··?(' .'~ -- . . . ' . ~ ~ . ~~\0 . - ·. . . . / I ; I'

' ; • . . . 0 • . • •

.· Table 16. ·.' Age· coinposi tion··,of· northern pik~ from Lob.sti~~ . 'for . ~exes _. . . . combined and sex~s separated (sample sfze in parenthesis). ·

. - ' (

-· . · Age . . I Percentage of fish .· in eac.h· age class • . • ' (J '" ) ·. .. -wears

·'

0'

.. .

. , , n

" " ; ' ·i i r

·t . ~ !-

. . ~ ~ L .; .. r! " . . r ''-

{ I

. . \ '. <,) ·. 1

' \ ; . -. , !

' r ~ '

I ., .... I

;.

l -2"' . ;

-· - . . 3 ' . ' 4 5 ' '6 .

. 7, -8 .

·g.

"' 10 . 11 .

. . . •12 :'-. I 13 .

14 . . . 15 .

Totals

. ·.·

. I. : . . . .

. .· . .. ... .J.

. . I .

- . . '/ · .· . ..

~~; . . ~~-·

.. • . , I .. . !

·. j

. . . . . ·.· .... .

,• '

. ~ . .

I

• • # •

I

I \ _.

Males ,/ .

" l. 9 . ( 2) . - .. (0) 0.9 (l) .1.9 . . (2) 4.6 (S')

~ 1.9 .. (13) ·22.9 .(25) .

. : ' 22.0 '(24) ' / 17.4 . (19).

8~3 .·.(9) 7.3 . (8) 0.9 u (l) .

(O~ (.O (O}

100 (1 09)

,.

' " I ~ :

..

' . ' . '

•

I • o o \: ' .

· ·~ ' . . . . . .

' • . ..

. Femal_es Sexes c.omoined

1~o · (1)_ '(3) . . '- .1.4 . . - . . . (O} (0) :

(0) Po· 0.5 (1) . . . -(0) 0 .• 9 ('2)

-6.7 (7) 5.6 (12) 10.·6 (11) ·.

' 11.3 (24) .

26.0 (27) 24.4 (5,2) . .26.9 (28) . ' 24 .• 4 - (52) 14.4 . (15) i 6.0 (34) . 5.7 (6) 7.0 · (1'5) ... .. .r ·. 2.9 (3) . 5.2 ·on-· ·.\ 2.9 ( 3) h9 - ~4) .. ' ~ -- . (O) · .. .. ' 0) . .

1.0 (l) . o.5· (1 -) · " 1.9 . (2) . 0.9 ' {?)

100 . {104) .. .. 100· (2l.3)' ., '

j

. . . ~ .

I . . .. o .

/. ·

\ :· .. .

. . . ' ' ... -~·: ·

, : I ' '

' I-

. I ·. \ : . .. .

'<. • !,) ·• .

' , . .

IJ / ' ·-

: . .. ..

·-. ..

· '

.. ; . . ,

" .

...

.. . '

• • • IJ

. . '

• ' ·,

··· ...

,.. . . ·, .

: I '

' I · .. . : !

... . ·=,/ .

- . . . . . -:...-.;,.-... _ .... __ -·~ · . -.~ ~. - -- . -... -.

... • ·-· ·-· .. --.......... ,.,;:.~-....... ~::;4'1>,.....;:...-~~~'t.~·:wir · 1 ... ·.-;a;nman

. . I . . ,. !

. I . '·. 1

' !. ~ -

--! - ' -:-:-· '

, ·

·' :

. . , _ !

.. ~

: • t -

-·

•, . - "' • <r '

. .-- --~---·-- - · ... . . ,.----.---- ~

- ---• ••• ;.~.~- -· : , -...,... .... -~: ...... ~_:__ ·- c_· __ . . .. - ··-·· .-·· . .. ......... . . . - - . . -

- · t • • ' . --I . '

Tabie ·1,7 •. · Logari~hmic and exponential - regression _equati~ns_ -fo'r the re.lationship between:f~rk I · · · · - length (L em) and whole we'ight (W kg) ·of n_orthern pike. from Lobstick, Labrador •. - ·' .· I . . . . . .' · '

-. - ~ Log .. regression ·form • r

._ ... :, ' j - - -

1 l I Males log W· = 2.~~15 : 1og - L ~ ~~05?8 :

log W = 3.1822log_L- 5.456.1

. W ·= 0. 000009 L2 • 9 6 1 s w = o~ooooo3 L3· - ~ 822

. 0.98 0.99

. . . . -~ -F~males

Sexes -.Combined -- . 1 og-W = -3. 0634 1 og . L -· 5. ~401 W = 0.000006 L3,0634 0.98-

TabJe l8 .. Empirical and caTculated average -whole weight~ (kg} of 'the. different fork length {em) i~tervals ' of r\orth~rn· piKe_ from Lobs:tick, Labr~dor • .

. '.

' ; ---------------------------------------------------~--~------~------~----------------------------~---Sexes' Combined · ... i - Average · . __ Ma _l~s •· ~Fema·les

,..;.. ~ ' length · Eriipirka.J . . Calculated- ~o ... of .. ·. Empir1cal. Calculated No: of ., -' (Gm), , Weight _(~g) Weight {kg) fish - Weight {kg) Weight '(kg):- - fis-h .

Empirical · Calculated No. ·of ·­We1ght- (kg) Weight (kg) fish

0;01

' " . ~ · ,

. .. · . ' . ... e. . ~· ... -. '

. ·-' . --,

. -- 1-· r I ,

L ·- .. , ' 'l

I .I

. . .. ,

- J, ' . ·-

:;~ . - . .- . ~- ~ -· . .. - '

/ - ' '· '· ' ~ .·t ,' ' . ' '

;i­t .J 1 j l

1-

i.

I j' i l

l :1 ·J

~ (

-1

I i

l.

.

. '

y ••.

~ 8.

I ,'

, I

I t I

l. < I ~

I

" t t ~ L . r-r i: •. i

. ! . - c

I. t

I - . -

t t

I . ·~

. .. ..

. .

.... ---:--"--·- ..

/ ,

-·. · . ' ' .

~ •.1 •

. -:. ·. Q) -

r .

' ··

I .~ . ;

0 .c. . ~

. . , ·

5.0

. ·1.0

•

'MALES ., .• : FEr-tALES W = 0.000009 L 2 • 9Gis ·w = o.booooJt

·r- -=-o.98-\ ' .

.r · = 0.99

•'

·' .

..

'1

:··,'

· 20.0 4o.o··so.o eo.o

. Fork ·length ...

3 ; 182 2 ••

I

:Fig. ·14. ,L:ength;,wei ght re 1 ationship·, -sexes sepa rated, of northern pike f rom Lo_bst ick, Labrador. :- .

· -· ~

•,

; .,

' . ;

./

•· • · .1

. .

. ' ..

.·

.·

·- '

I .

.. .- '

.' .. , ., , ,

' ; ~ '

I .

-. -·:----·--:--___;, __ _ ~__,__.....: .. ~---\-- ... - · · - f- · -- ·· ---t.-;__._. .. _,_ .. - ··-- - -·!-·_..:__ ,._:...,.,,_,,_ . "" / . • ' "'·· .

"P!!'h """!0!'. ;:t...,SII'!I!!E~P.I\;P~-!'!1!!. -. ,""'' I'PI! e-.... BI!Ol!X'!!"!.9 .l""'i ':"": lfE~, ""'#..,,_IMI!.""'""""''"'""!· z._,...;_ ._......__:. _ __ ,_:_;.:._~--- -~~---~~-... --.· .. ....-- ............... -~ -•• -_..__. ~;r _-----:.· ..:.._ .. ........ . ·-·:· • _. - · • . - • • " o ' O"- ~-- • ••- .. • • • * • - • • A , • • • • -~

--! . --· ;.

I

l .l . i

•I .. . i ·i·

.~ . i j.

-·.I --, . t.

I

: ­r -

-1. .- i .

-r . . ~

.,

- ' l

-. ~ -· . . \

·-. --~ . ---

\ . '

' -'

·'

._ L~

Tabl~ 19. Comparison of .the_' calculated fork. leng-ths (em-) of the diffe~ent <age .. groups ~ sexes combine·d, - . . · ()f northe~n pike fr.om jOlJ.r 51reas of Lab r ador ( sample ~ize · in parenthesis).

Age ·· (years·) -

' · . ' 1

"- '1 ' 2 -

3 . .

4 '

·5 .

6 7

.. 8 9

10 1_1

12

13 . 14

15

1L3 . ,· ·14.8·. 21 _.9 24.2

~ 31.2 33.6 38 ~ 4 4L5

44:3 . 48.1 '49.7 53 ~ 5 54.6 sa:o 58.7 61.4 62.9 - 64; 5

67.0 67.6 70.4 --.. r6~: 7

74.3 7-1.-9 .

. 77.0 . . . 78.1 81.1 - ~,o.4

88.5 82.3 ..

·- -. .

----

0

Sea 1_es - Scal es .

1 2~0 i'o.2 7.8 20.2 . . . · 19 ·. 7 20 .-2

-.· 27.6 29.·5 31. 7

33.9 36.1 - "41 • 9. ..

40.1 - }' . . ~6.1 · 50.5 > 46.0 / 51·. 7 . · ~7. 3~

... TO.'? 5&~ 2 : 60.8

55.8 60. 1 ~ 64.6--, 62 : 6 : ~ . 62.9 67 . 6

··66.0 . '65 . 5 69 .6 - 67.5

. I • • . 70 .• 2 ·

.70.0 71 .4 .

71 • 1 . e -73.0

. \'

-· . .. . -.. : - ' .. - - .. ~-

- I . -

• I·

• J

I· •. ~

. .

.r I

. ''i . i

. i

. I • I

' . ~ :

-•,. -. ; . .

!

! .

I I

\ ... _, .. . ,I

'\ .

__ ,· ;:, · .

. ~

Table 20. Empirical and. calculated averag~.:.weigh-ts of. the different age-gr9ups ·of northern pike · from

... .. ··.Age · (years)·

' ...

---r

. . 1 2

3 ·. 4

5

.. 6 7 -

a g ·

lO ·1,

-:· 12

13. H 15.

"

Lobstick; ~aqrador. · ~ - . \ ~ . 1 ·

- -~ . WhOle Height {kg) .

· Males · Females Empirical

Mean .Range

- o-~m ·

0.14 · 0.1921.20 0.70 _,

·o.a1 0. 37-1 . 09 ·,

0.96• 0.42-:-1.75 · l :s8 ... 0.35- 2.85

1.60 0. 38-3.14 ~-~2 ,0 .,48-3.18,.

. 2.35 . l.65-·2.93

2 ~ 91' 2 , 50-:3-.68--3. 16' .

-

. ·· Calc. Elripincal Calc. .., Sample ·

Size .. -.~ :· .. .. ..

b

Mean Range Sample_

. Size -

2 0 ·

. 1 2

5

. .Q. Ol 0.08 .•

0.22 0.40

0 .. 63

13· a·.a8 ·

v

·0 , 01

~ . -0. 71 . 0.40:..1.20 0.86 0.26-~.32

· 2s . 1.J8 1,8"'2-.- 0A0- 3. 16 .

24 L43 2.42 1.10-3.8_0 19 · Y. 76 2.60 . o. 70-4.-05 ·-

. . 9 2·.15 .· ·. 3.41 . ·2.22-4.38 ..

8 2 ~ 52 3.08 2 .50-3.85

. , ~.22 4.08 3.37-4.58

0 0

· o

I . -

4.30

4; 91 . 4. 7 4 _. 5. 08 .: .

,. :

0 "

0 0

7 ' •

1 -~~ 27.

. '28 . 15

6 .. . 3 ' .

3

0

'2

o.oi 0.09

0.26 .. \. 0.49

0. 74 .

1-.09 1.42

'1, 84 2.29

2. 71 .

·3.13· .

3. 73

3.95 4.63 .

.. 6.07

Combined

, Sampl e Mean Rang~ . . Size

0.01 3 I . 0

·0. 14 · '. ,, ":

0 . 70 0.19-1 ~?0 . 2

0.75 o~37-lf20 12 0 . . 91 0.26-2.32 24 1:71 0. 35:-3 •. 16 . . 52

2.04 . 0.38~3.80 . I 52 .. 2.22 0.48-4.05 34

2. 78 . l. 65-4. 38 15 •'

'2 . 96·- 2.50-3.85 ' 1-1

3. 85 '3, 37-·4. 58 . ~ -r"

. -· 0 4.30 .· 1

4 ."91 . . ·4··: 74-5.08 2

. -0,.01 0 . 07

0.22 ' ' 0.41 .

0.64 .· ' . r

0 . 91 1.21

1. 51 1.86

·2 .26 '

2.63

3.11

3.46 -4 . 04

5.30

. . . . .

;::,. (X)

"<:: I

. '· \. ,~.

. ' _, .. • : ~:-' ·:·:~. ''. ;, __ :<;:. .. ;,.,--:...._.:" :";;<_,;;;~...:~;.;_:_;:.~·,.._ ... ~,.-• .:,:... .. :.. .:,.._,;,,~~·-. .;;..¥...-.c;.,,;;,,;;.,·,~~'-""".:..~::.-~! ;..:.- -~ ..... -:--;;;;...;~. ;;,_,;;,£,~~{&~~~-~

. }

' ...

' . ~

J ' \ I ·• ~

.1 ·' 'j .. '

·-.· . ~ .

·, .

. -\. .

.. / > · /

.. .

. ' I ~

r ··.

·, • '. 1

'. r j; ._/

' ! •.. .. . ( ~-

r. i.'

. ~: f;· f~

f. · ~-

·t . ... ,:_

. r .

. ·· .. . . . . \ .. __,.. .·· --.

..

. ,

.,

• I

~1ALES

-Cl .J .¥ -- G .c Cl

QJ

~

1!-0

\ . - 49 -

FEMALES

•

/ '

.. · ....

l .·I . I

I

I r . · ..

' ' '

· 4 8

' ' SEXES cmisrNED

4.00 / . . '

/ '. 3.00

' .

2.00

· ' .1.00

'·

' "

4 I .

. . i

. :

. . . I .

·8 .·.·• ·,,

.. - ,. :· • '.

. '

. ' '

· 12.

I I

,,;;t. \ . ,.~ 4 8 1'2 "' . ·,

•••• : ·Age . (year sf

. ·. _Fig. 15. Emp.f.ri cal .. (scatter . plots .an<f ranges) and ca 1 cul ~ted · .· · {fitted curves) a·verag~ weights ( kg} of the -different : age-groups-.of. ~ortherrf· pike from Lobsti ck ; l abrador . .

! . ' I ' ' ' • • '

'/ :l'·' . '. . . . . . '. ' . ~ . . ' . . · ~ :~:~:.~~~------· - .- --- ~- ----~-~--:: .. _-~----, . . ... .

'. ; ..

' ' '

J ! I . ' . I

.. ~ ' ·: I . .

. j ... 1 ' '\· ' i . ) .

I ~ .j

·. ' j . -·--- -- ·--· ....... ~ .. : .

....

. '.

, .

} ' ; ,

. ' ·

t

. ~ . ~

! I. I. ,., . ~· ,. ]·

r t- ~

' : . .

'

~ : ... ·.. .

. , .

~ ' - .. ~

' ·'" . ' . . .

/

. .. - ·50 -

calculated age-weight data;. t~e sc~tter plots and ranges represent

ttie empi rica 1 ~ata. ' . . .

Simi 1 ar to the length di stri buti on, the weight distribution of I .

age. groups (Table 20) exhibits o,verlap in weight .between ag·e groups,

· the 1argest ove.rlap being fo·r 9-year-old females which range in ·

weight .from 0. 70 to· 4.05 kg." .

I ' ' ·. ·4. Coefficient of condition

. .

..

· · On.ly condition valu~s of m~ture fish; .\'lith empty stomach's .at ·

. · ·the ti~ of.."capture, were used ·to· sho~r the change in the coefficient . . I . . : . . .. . . . ....

. of· ~ondition ·from Jurie to September (Table 21 . and Ffg : l6), Of the . ' . . ' .. .

fish samp'led, . ~axi'muni .conditi ·onwas ' reached by the mid<;lle of June; . I .' . . .

minimum condition values were retarded in late June .

. · . · · ~ . . ..

·5. Marta 1 ity . and 's.urvi·va" . . .. ~ ·

results · obtained were: for m.ales l = 0.32, A"' 0.27 and s·. = 0. 73; · . . . . . ' .. . . . . .· for .feinales . l =· 0,37.;. A ·=.0.39 and s = 0.61.

. ·C. Reprodu'cti ve Bi'O 1 ogy

1 • . Sex . ratiOS '!' \ -

,.

' I

./ . \ . . . . . The ratio·.of males to females did n_ot differ signifi~antly for

' . . ..· . ... . • '

~--------· --·-· _. ____ ... ..,.._ .. __ .. ·.-' ...... ____ , ...

, · .

/

. ·. , i ,.

\ .

. . ~~

. :.~ . .

. ::.

) . i ____ ,__ ___ ..,._.......,......,......,___ .. _--=----~----·- ... 6- ·- ~-- _, .. , -- ___ ..,,__ ... __ ~---~ .. - - -- ~ . . - - ~ . . .

, ., . . -r

• I

. I I

. i . j

:·

·~. • I . . . ··

' · .. \ ' .

•\

·. '

:_ • • • • • , ;.-:.~-~ . .. .,. ·... ·.:. !. ••

,, ' >,

-\.,

:::

Table 21 • . Change if coefficient ·af ·condition·. · from .June to S~ptember 1978, of_mature nort{lern . \ pike, stomachs empty at -time of-capture, 'from lobstick_, .. Labrador .

. Males .. · Females· Sexes Combined

·oate of . · Sample Sample Sample Capture · Mean· · -Range Size Mean Range ~ize Mean - Range · Size

5 June b. 74 0.62-0.88 10 0.73 o·. 71-o. 74- 2 o. 74 . o. 62-o.·aa 12 '\ .

' 6 June ;, 0.68 0.54-0.76 7 0. 72 - 0.68-0~75 .· 4 Oo'69 . 0. 54-0.76 11 . ; '\ '

8 June 0. 81 -· . l . - 0.79 -· 1 0.80 0·. 79-0.81 2 . : ' -

-. ' . 9 June · · o.76 0.69-0.~4 0.75 0.68-0.·82 7 Q;76 0.68-0.86 '21 1 o June 0.75 ._0.69-0.83 ' . 6 ' 0.78 0.72-0.8.2 8 ·- r 0. 77 0.69~0.83 ' 14

13-June '. 0.38 ' o. 82-0. ~1 4 . 0. 75 0.62-0.91 16 0.70 . 0.62-0.79·._ 2 14 June _- o·. 73 · 0.62-0.8_9 .. 17 0 ~ 79 0.65-0.97 15 . 0. 76 0.62-0.97 32

16· June 0 0.83 0.78-0.86 4 0.83 0. 78..:0.86 •4 20 June . ·o.s7 0.49-0.70 3 · -. -. o· 0.57 0.49-0~70 . 3 .

23. June 0 ' - 0. 71 0.60-iJqg 3 0~71 · 0.60-0.79 ' 3

7- July · '0.}7 0.63· . 1 0.70 0. 63-0.77 2 14 July . 0.64 0.56-0.75 3 0.85 0.83-0.88 • 2 . 0.72 - 0.56-0.88 . 5

21 _July 0~73 1 0.7-3 0.63-0 :-82 ' 2 . 0~' 73 a·.63-o.sz 3 I

22 July · . 0 :- 0. 79. 0. 71-0.86 ' 2 0.79 0.71-0.86 2

8 Sept. 0. 75 o·. 71-o. ao 4 0. 72. ·0. 61-0.82 4 · ·a; 7.3 0.61-0.82 8 ..

' ·.

·. ·\

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o.so

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. 0.50 ·

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· Fig. 16.

. I

.. ' . 5 .: .

~ 52

, ·

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. '•

· ' . · :.

.

.. ..

July ·. August · September -

. i Change in co~fficient of .condition , ff,om · · June to September .1978, of mature nor1hern .pike, sexes -combined,' stomachs· empty t time of capture, from Lob~ti,ck, Labraaor.

I • " • " ~ , , , . • , , , . . .

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2.5

2.0

1.5

1.0

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: ·· .. . ··MALES

v=s:sa ·-o.32X

· r = 0.93 -~

/ ,

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,--·

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v = s.'85 -. o.37 ·x :.

r = 0.89 >"

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5· . 10 5 / 10 ; :

..

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.. . . .. . Fig • . 17 .

.·

. Age < years> . . . . . . . ..,.,

A plot of numbe r of f i sh ca.ught (natural l og arithm scale) on .age (ari thme tic scal e ), used to esti mate t he instan taneous tota 1 roorta 1 ity r a t e of nor t he.rn · pi k'e from Lobstick, .l a brador •

---~-----~----:...._~.-· -- . ~-~ - •. ·• .. •

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-· · any age group· (Tab l.e l2) • . o·ata ·were g~buped for ages . l-6 an-d

• • J • • •

10-·lS ·where sample sizes were small. Ttie overall male to female . - .

ratio ~.as ·1. 04.:J .00. - I >

· '-

' 2. Age and length at first maturity . . The percentage of -mature fish, b}l age group, (Table 23)-shows

that males are predominantly (50%.) matt~re ·by ag·e 5; females are not . - · ·

·. predominantly mature until age. B.

_The _percentage ·of mature fish., ~Y l~ngth class·, (Table ·24) · . . ; ·· . . . • . • fJ . . .

· shows _that mal~s are. predominantly mature at 40 ·em, f~male~ at 60 .em. " . ·-.

.' .· For sexes combined, the pike-are· r)ot enti~ely _mature until .· 75 em.

. ' 3. Fecundity

Fork · lengths were grpupe·d into 5,.:0 em intervals and_ -~he rrean

. : nflmb.er of· eggs ·per female was determined fo~ each (Table 25-and · : . · . . : . .. , / . Fi!;J • . -18). · The. empirica1 data·, fitted to a log r .egressi cpl, .gave the' . . equation:' .,

'• / ,

log F = ' 3.7~ · ·logl __ - -2.48 (r = 0.77) ·

~there 'F' is .the ·number of eggs and 'L' is 'fork .length· (~) . . · The -. . . .

:·cal cul~ted nurmer of e~gs per female -·\'lq.s c~niputed from thfs equation :

\~eights \'lere grouped ·into 0. 50 kg intervals an.d the ·mean nutrber

of· egg~· pel" f~male was detennined for . ~ach. {Table 26 . and .Fig. · 19).·

.The_ empi_rical data, fitte~ to ·a ;log regression~ gave the equation:

· _ . ·1 og F = 1. 21 : log)J +~ 3. 83 ( r· = 0. 81)

where 'F' . _iS number of eggs and 'W' i.s whole ~eight (~g) . .

• ' • ~ I

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0 •

: . : ·. . . . . ~ . . . • . . . ;l

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I I , .. . - '55- .

. ~·

·_Table 22. • cl '• • • •

~Sex ,ratios- of i10rthern pike, ·by ·a'ge-group, . from . ·~b.[ador. · · . I • . • ·

AC$ (}'ears ) 1 ~6 ' 7 8 ' ' 9 ., 0-15

' '

.Male 23 ' 25 24 19 18

Femal~ 19 27 2·8 15 ' 15 X2 value " 0.38 0.18 0·.·31 . 0.47 0.27

\

Si'.gnificant. · di He renee . None None None None None

... - '

•

lobs t'i ck;

Total

109 .- \ 104

0.08 '

None - ·

Table 23- Percentages of mature northern pike,' by age-class, from -

' o I

· · lobstick, ·labrador· (sample size in parenthesis)._ ·, '

Age · (yea·rs ) · -

~-1

2

3

4

5-

·6 . . 7 8

· g : '

10 ' 11

l2 13'

_.14 . ·15 I

. • f .

I'

( ' '

-, .

\ ' ' ,.

Perc,entage of mature fish

.Males ·' ·.- Femal es Sexes Combined

1o 0. 0 .(2). ' . o· .. o. (1) ' :. ' ' ' 0.0 : (3) . JO) {0) . , .. (0)

0.0 (i ) (0) 0.0.· (.J)

50.0 (2) ' ' (0) 50.0 (2} I

75.0 ' (5) ' 2~L '6 . (7) 4.5-.4 {12)

76}9 ' (13) 41.1 · {n r . 6P~o · (24) '

87 .s·· (25) . 42.3 (27) ' 64.0 (52) -

"'100.0 (24 ), ' 60.7 (2~) 78.8' (52)

94.1 ' .. (19)' 94.4 (15) ' 9~. 3 (34)

' '

. 100. Q ('9) loa ·~ o (6) lOQ .0 .{1-5}

100.0 (8) .· 100.0 (.3) 100.0 (11 y-100.0 ' _(1) •' ' 100.0 (3) '100. 0 (4) '

(0) / (0) ·(O) .:.. -

(0) 100.0 .' (1.-) ' '''100 ·.0 \ ' (1 ') .,

.:. (0) - 100.0 '- (2) ' 100~ (2) . '

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rabl; 24. p~·rc·entagesof matu~· n~rthe~~1length class' fto• . · · Lobstick, labrador ·(sample s,iz.e .. in parenthesis).

Fork 1 ength · (em) · Ma.les

2. 5 · ( 0)

7.5 ,' 0.0 {2) ,;•

{0) 12. 5· ' ' '

17~5 .: { o')

' -· Percentage·of ·mature fi~h I

Females

.{0)' "

' (0) ·. , I

.0.0 ·(1)

.-· : (o>

. -Sexes Combined

(0.) ..

0.0 (2)

0.0 ' (1) '

. (O)

·I

'

{0). -. ' (0) - (O) · . .-, 22.5 .

27.5 ' 0.0 { 1) ' ·- (0) 0.0 .(1)

32.5 ·_' ', o.o {l) .. - .,(0) 0.0 (1)

100.0 {l) . . 33.3 (6) . ~2.9. I (7)

' 75.0 (12) ~2.5 .(_8) ' 50.0 '(20)

90.0 ·-(io) · 16.7 (12) ~ . . 50.0 _(22_} ..

37 ~ 5 ., '<

42 . _5 ·

47.5 •I . '

(251) ' ' ' ·, .. 2 5: 0 ' ·~ 16) "6;3;f· ' (4~) . '88.0

89.5 ' (38) . 33.3 {24') • . 6 ·7.7 . (62)'

' 52. 5

.57. 5

100.0 { 36) ' . 61·.3 ('31) 82.1 (67) . -/ . 6a. s ./

. 67 .·5.- ·.· 97.6 (42) 73.5 -· (4_9)' 84.6 (91)

100.0 (19) 92~3 ·( 39) ( 94,8 1 (~8) 72.5 .

"

77.5 . 100.0 ' (2) ' 100.0 ' ( 21) 100.0 (23) / ' I

o:O - ' ·. (0) . lQO.O ·. (11) ' 100.'0 82.5 '

,87·. 5 (0) ' 1 00.0 {,2) 100.0 (2) '

. ' . '

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.j ,j · i .. ) .:

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1 ',' l . '­~ '

~ ' ' . ~· .. : ____ -__ : . .... --.... -- --·- -··--- -- -.-- - ' ·"' ~---· ·--:-·-------:-;·

' ';. , •. --... - ~---.• ··- ....... .. __ , . .. 5

. . -~ __ :

· / ' ..... · • ... . ~ ~ • . .. . : •.• i--~,.. ~- ~- , : ~ ~-~ o '( •'J ' -.~. J•,· ..... _ .. ~ :•\ ,; ~: .. ......... :;~~ .... ~~ ... --~-~~·)t.\.1..,,--;-: . ..,.j• ,,r-r.-::; .. ,!';~~·:"'·"'r•--,;:--::-..,.,~. , ""';-: ~.,.,..,.,~ ... ~---..... --. -· ·•-:' ~ .. • ;-·

. ' ... ' ' . ,.·. . . , . ' '

· Table 25 • . c

' ...J 0

.. -.. ;.

- ,~'.'" . ·- . . • • ~l. .. ·.

' •1 ;.· . ... , ·- ., . . _ .·.57 --' .. '

'• ...

/

.· : ..

The rel,~ ti~nshi p between ·the. number bf ma~ure .eggs (greater than· l .0 nm i .n diameter)· and· fork length. (em) for .49 northern pike from Lo.bstick,· labrador. -.. · · · ·

•. ' . ' .. _:, ,. ----':--:----.,.----:----__.;_---:---:.--..-:--..:__~---'-;..__;,.....:...__,_.....__;__.,:..._ __ ..:....,......:... ..,., Actual '·Numberof Eggs· per. F.emale . _l!, ,", Fork length

· , · . ' ,l

. ' j ,·

/ . . '

. I.·. .. . · (em)' ·· Mean . ·Range Number of fish

Calculated Number of EQgs per _Female .

·~.~ ~··

. I . • '

52.5 ;

57.5

62;5

'67.5

72.5

.. 11423

ll -544 .· ... . . 13969

. . -~ 2·169.5 ..

. . · 27348

:-' .. 'fi367~16720 ., ... _:

• ;' 5'732M21983 <•• . 10382-2-9200

.0•<.' . : .

.. 135·70-:40000 . •:

1 .

2 . 5 .

. 9

. .8062 .

11298

i5394 ~

20481 .

26699·

' •

:J : 't

i

T -~ .. 1 j '

I .

{l '

·. · . '- 77.5 ·. 33414 .

.. 46945

-~ - . '

' 241 00-475001

. 15. '

·-10 ·. . 34194 ' . '

43121 53640 .

f· !· \'

I .

' '.

' I

l ·, I

:\ '1: . . .

; r

( ~- 1 ..

,. ~ f

L

. o'

. 82.5

87 .. 5 I • '

'47050 .• "

' · .. .

/

. ,•, .. ' .

. 29752-73873

. 321 00~62000 ·.

' . ,-,;... . . . ~ '

·5 2 :

' ' ' : . . ;._,' / .

.. . ~ ..... ' · t

I •

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.. .. :- l ., . "l

Table 26_. :The telati~nship between··the number of ~atu~ egg-~· (grea·t~r. tha~ l.O mm · " in di~meter) per female and weight (kg) for ·49 northern pike fr()m- · .··

lobstick~ Labrador.. · · : I. ' 0 I ~ .. ., . / j~·

~------------~----------------~------------~--~----~-----. Wh~ i ·e weight . ·"'Ac t"~a ~ N~mber of Eggs per Fema.l e

.'I

· (_~g) . Mea·n .. · ~ange :

1 • 25 8895. 6367 .. 11423

1. 75 14712 12991.-16720

2.25 18488 / . \ :. 5732-~9200

r • 0.

135 70-38836 2. 75 . 24524.' '. '

3. 25 28304 .15330-40000 ..

3. 75 32799 28000-42800

3,9500-52000_

' 36300-7.3.873

4.25 .. . 46333 ... '

0 4. 75 '55087,: .

5.25 .. 47QSO 3~1 00-620!)0 ... . . ~ .

~ .

: ' .. L ..

• b . •

" ..

Number Cal cula~ed .Number · ·. . ) · . · of fish :. · .of ,Eggs per. Fema~e .. , .. . · · ~

2 ...

4 7 . · . . .

10 10' ..

9

.3

2 .

2 ....

I ·.

..

. :~ . . .

. 894~ < -.1.3435 . .. ·

. 182H) ,

i3l15 . \1

284115

33787-

. 3~312 44975 50765

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- • • •• · - ·----· --.. <n· -~.-... -..

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,Q .' 30 ·e I I ... ::J .z

' 20

·.

·.· .. . . ,; .·.

; ·.

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\ .· :' .~ . .. Fig. 18.

· ,

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• . ·. . ' . .. .. ,

.... . . · ,•

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I

600 ....

_/ . , . I

. · ·.· ~ork ·length ( em ) . ' '

r ·- •

The relationship .between: fork length : {em) •and egg nu'mber in northern pike from lobsti ck, . . .labrador .. {scatter· plots and . ranges' represen t .empirical results; fitt~d curve represent~ ·. ·

·. cal cul~'ted regression}. · . . · ..

=-... • ' ·I ·

(

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... .

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· .. ' .... :j ·-·C..-~---· _. _._· ·-~~:_· __ _ ·.:~.·6-: . .:...,.~·:.~-... ~ · . . . . . . : ••• : : • •• --,--.,.....:-----..--:----:-_:~~-:--,.-.:.... ' ' • , j

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·· . · .. . . . . .

<.,).

· ~ ;o;.._~;.,,;~t:•·~rfc"_~ ~~~~,,......,.~,..,..:-'",."·';..,.,.,._~-·~...;...;..,;..,~~·'!1,rr~~r,:?.iq,.~'·~~~pt~.:r.'~~i~."l"'t!!','t> ··· '

. : . · :·

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70 ·, ' >1. ·.

60

....

r~ ...

20

- b

/ · .... . ._ . .... . .-.w'~~·i·a : w•i~-~~;~- < ~o ·> . ·._., · .. Fig .' 19 . . Th~ relationship ~e'tw~en · whol~\iefght (kg) and

. ,

·_egg n~ ·r in northern -pike f rom lobsticl< , . . l abr:· _ (scatter plots and ranges represent ·

, eq>i'r~. 1 res ults~ ~itted . . curve · represents>. cal cul'a ted regression· ) ~ · · . . . · · '• I , .. ...• _ , • ' ' .

.. ~ ' ... . ,. '

. ... , . -.•,.

..

., I

.·

-:·." ' ·.· · :

---~--~----...,------:-'~-· _. l __ _ T!li:J . ..... •, - --~..:;. : .... :....· .. ": ... . .:. 1' •/'

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., .

··:· ...

. : ~ .

. . ' - 60 -:.. :

. The. rel··ationship between the .number of mature eggs per

female and age is given in Tab,.e 27 and Fig. 20. The· empirical

data, fitted to a log regression, gave the e~uation:

log F := 1. 36 log A + 3.11 · (r =. 0'.54) · .... . . · ~

. · wher~ 'F' is'the number of ' eggs an·~ _ 'A' is a9e ·(y~ars) . / .. 1. J'.

n~ Food habits ' .

' I

' .

\ .

I

'·:. Of the 386. stomachs examined for fo9d contents,' 240 ·or 162_% were .

. emp1~. Tne_'prj1cJpa··( foe~ it~ms ~~re: whit~fis:h . (6~-%:} an·~~· un_ide~~i ~ . :

ffable fi~h remains (25X) . .. Insects .- (~%), lake chub (3%) and burbot

(3%) \'lere also present . . ·.

I ,Of tile fish angled ... )'0%. had empty stomachs as oppos~d to ·. ::. ' .

' appro~ifnately 50% f.o.r those caught by fyke net,- gill net or seine • . . . .

A comparis·on .of the food ~a ten by pike .. M va ri o_us ~ i zes.-

. · (T~bie .28) shows that l~rger fish tend. to -eat larger food ite~; . . . . . . I

' • • ..-. ' . ' • I .·

the diet. becomes en~irely piscivcirous, mostly·whitefish, the mean I

· si ~e: .of \'lhi ch are 1 arg~r · than any of the in-sects or lake chub found . . . . . .

in the stomachs of .sm~l-ler ipike • .. There is als·o· a~ increase_ in the. .: · ,I ·

.. This · may be ·

. . l .

·. 1 . \·'

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· I . .; . .. .. • 0

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1) . .. , . I ' .

.,._, .... " . . ';- . . . .

· ·_ .· -:·~~€~M..,_ -,...,:'''""'""'"'~'~"'~"'.._.-:-.... ~,.....,...,,....,..,..,..,.~Il:!'~>~l~~?.L"'!~~·~~~:.~'!':t't~-~w~:-~·~JVJ1'"::~'.:C"~"~""-\"~=·s~·- · •

,. . """ . - 61 . -. _, . ~~~ . . ~· . ,.

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l . - j r . I

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. . '( -

I • ' • . I

, I r;. '. . ,~w .

-t -.

Table 27. :r _he relation_s.hip between the number qf matu-.:-e eggs ' (greater than - .. ----. . 1.0 mm in diameter) per_ female 'and age (yea~s) -for ·4a n~r~ern. · ~

. Age _ (years)

5

.6 .

7

-8

9

. 10

.11 •.

12

13_

14 - :

15 .\

pi ke from lobs-tick, La bra d0,r • • 'I , .... • • •

. 1 . .. •

. · Actual Numbe-r o·f Eggs per· Female

~lean . · · .- · Ran~t . ! '

636·1

5732

_.q9713

. 25318

I 29398

-· . 1142_3:-28276 .

i .299l-42aoo··

33485 .

38836

319~~~

.. ... : ' · ' .

" ·

1 0_382~ 73B73

. 13570-.52000

: . - 1 ,•,

21983-47500

--

-,, • · ' •• 0 ' \

.,

Number of fish

I

_1 .·

1 -! . . 5

... }4 - ·: ' - I

13

6

·.-_ 1

6

.. () 4 '

0/

1

...

:

talcuiate.d N~mber of Eggs p~r Fema 1 ~

~ ', .)..

: . 11391

- 14597 . -

- ~ . 21586

25336 ' . .... .

. ~9240_. - ~

33287

37468

·-

41777 - . .

4.6207 .

50753 . -

. . - . '

:~ ,;

.}

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F = 1276.37 A 1 ~ 36 • f •,

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Fig. · 20 ~

.. .,.:...;...,,...._ ___ '"'7'"'-,-----

u : •..

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... _

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. . ~ ·

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• ·: .

. ·':."·

• ••• •

. Age · (years) · t

The relatio~ship be~een age (years} and egg nuinber in · nort~erri pike from Lobs ti,ck,-· Labrador (scatt·er plots .and ranges.· represe-nt empirical results; fitted curve . represents ·calculated regression) •. ·

.. \\· . . •.

) f. . ·'

/ 0 .

/ ·

.. . ·/ . '

i, .

;.

· ,

1

1

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:, · 1

'\ _... . .. . - ·:_.~ :_. · : .. . ..__..-. .

·. . . . 7

·Table ·2a .·Percentage occurrence ··of -food items in stomachs with food prese~t · from pike of various. sizes f~oin · L<?bstick, ~abrador:. (sample · size _in p_aren'thesis). _ , - _ . ·· .,. · · . · . . -

Fork length inte~val (em) . . " \

· Food tYpe 0.0- 9.9 10.0-19.9 . 20.0-49 .-9 ~30.0-39 . 9 · 40.0-.49: 9 50.0-59.9 60. 0-69.9 -70.0-79.9 '80,.0.;89.9 ·- '

. \-- Whitefish : ": (0) -: (0) ' . . - (0)' . - (0) " 40.0 .(8) 71.8 (28) . 72.4 (42) : 72.2. (13) ' 100.0 (3 )

:. I - ' · Insects

l ·I

_ · Lake Chub

-Burbot ...

100.0 (1)

· (0) ·.

(0) .

. :.. (0) 100.0- (1) ' 40.0 {2)

, j

-·

20.0 (4') . 23 .. 0 {9)

~ . ( o}. · .. _- , ( o) . 4o. o 1·_( 2 )_ . 30. o ( 6) · · · ·- - · ( o)

- (0) .- (Q), 20.0'' (1) . ' · 10.0~ (?} . 2.6 (1) ~ ' .

... (0) .· {0) (0) :-- . - '(0) 2.6 (1) -:-

24. 2 ' ( i 4) _ 27.8 {5) -. .

· - ( <o> - (0)

3. _4 (2) .

(80) . · . .

(0)

(0) .· . ..

(O)_ . _·

(58) . ..

{0 ).

(o) -

(0)

(0 )

. (1 o') l l . .

. _· . S~omach empty . . .. : ·. · (1) . ·- . ,__(-1) . ·_ (-~) · .(4) · · {24) . ·(55) .. . ·

....... ~- \ " ' ~ -~----------~------~--~--~--~-~·~----------~~~--~~~~-----------:-------~-------------

- . . -' '.

. . ·

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• ~ - : · ~ 1• ' .,._. ~ ·r- ·· ~"1 ·-- .,.. .. ,.~-m ··~~ ~ --.. : .. ,.,..:.:::'• -· -.· .. -_· -~~-···· :,,..,.,...,... '"'~-:~-~-.~-~~ .. .,·11· r•'':-t;~ · ttt'T:'~,.,.:-r';-l'_..,~-~~7'1',. :"-~~· .. ,"~~:· " ., .. ,_,:·,':,..~....._- :~''?:'~ 'Xi';~"{"'.:·,t~ ... ,_ • .,.. ;''"!': ~-... ·--\~!';"'~':' .... ; .. ·1~-:-r.-'7:'-~'-":~,:·· ... ,. ;. ·. . 1

. '

' I

- 64 .:. ·, I '

' •,

.\ DISCUSSION . . I .

I. Age ·detenninati.on ,.

The four methods .of. ·age determinatiorr chosen for this study . .

.have be~n pre~iously used to assess:-age an·d grOI'Ith of no'rth.ern

. pi~e;· ·scales OHlliams 19.55),. opercula· .(Frost and. Kipling 1959), . . ~ ' . .

· cleithra (Casselman 1974) and otoliths (Hatfield et al. 1.912) . . .

The r~s ult~ of this study show differenc-es . j n b6th. ages and age~ : .. /: . ' . . . . . . . ' . ' .

1 ength re 1:ationshi ps ·derived from each aging· .structure. ' .

" Ideally, . analyses ·Of suc'h differences should be studied over

s~veral years. Tag a'nd recapture or ~adioa~tive marking ·exper:im~nt~ I . i . . .

were not feasibl 'e due •'primarily '. to the time ·constraint of the s.tu~y .

However~· the farge population size. and .openne~.s . of the .system would . . . ' . " ' .... - ~ . ' . ' . .

~-lSq have ·made it difficul t to' 6btain ~uf_ficient recaptures. · An

. a.iterna ti ve method of· compa'ri son_ had to be de vi seq 0 ' . . . .

/ ''

The. IJ)ethod chosen· involved comparison of age-length . · • ' . 7 ; ' ' , ' . . ' '

rel~_tio,riships d~rive.~ from ~ath ' agi~g structure.. ~he basi s . for -~ [ch · , I .

' '

·comparison i.s :that empirical ,af'!d back-c.alculated ag~-length . . . - . . . .. ·; . ' //~,.

· relationship~ should not differ, assuming. that (1) the aging ' structure / / ·

. ·: ~c~~r~tely r·eflet.ts -~~~ ._ growth' of the fish, a.nd (2) n~ ~g~FJg erro.~y/// · . .

·.: .·.have 'been made. lee' .s .phenomenon' co~ld ~au~e a 'difference~~ .. ,.,

empirical. an~ back-calculated ag.e-length ~el.ationshi~-Ho~~ve~,

~h·e~e djfferenc~s, if present~ rna~ be _uniformy l . of t~e aging

~thods.· . Harrison and Hadley (.1979) ! fo~~~/th.at for muskellunge Lee 's ' ·. . . . ,...-/ ' . ~ , .

• J ....... \

phenomenol) existed to a nearly_.... ~qual extent in the. back-calculated ' • ·, • , ·p ". , ' • .<"' ,#· ·- \ : , · ,~ ,

-lengths obtained from cl e'ithra and scales : If it can be sho\'m that . . ' . .. >/. . /

' ... .

. //~ ,/

/ , ./

./ /

'' .

~ · ... !'

\ . :

,. '

' ~ - \

' '· ':7.

·'

.. -~

, ' '

' -------;-:?· /

/. •

.·~---,_,--:.:.:.. ____ , ,\_ __ . -· ~----· ·· ... ---- .--- · - ··· ........ ...... ~ ....~. ... . ... , .... . · ,

/ ·' /

/ { .

. i

\

:. •

f·· (. ) .

' t i · ~.· . / i·'

'

\· .·. \

• !

1 i .,. I t

-j' ~-

/

· '

. . . . . . . .. . • .. , · ... ·· ,. ···; ... , ... ~ · • , ..... -.. ....... ~~· ..... -... ~ ~ .. ~ . -..,·~,;~ •w··-·; ......... ~ ................ ..... ...:.~ ..... ~--....... ~.,. ... "'''\'.,.. ~'~"/SII'r"'( t.l• :'1 ·r,"'~"7"'""'l r'"'"· ........ 1.~ "4~ . .. • ' :"" " ' ' ' '"- ..... ...... . .... ·· ~ · ·• ""S"•· .-,,.., , .... .. --~ ... - · ..... - •.

/

. ..

....

~··· ,

\

I.

. \

. . : ' /

- 65 -

L I -.

:each ~f· t~e four agin~: ~tructures \a:ccurat~ly reflec~· the growth .·

i . ~;.·the fjsh, then the aging ~truct~re from which the ' most ·similar

. · ~: e.mpfrical and· ba.ck-cal_c~~~te~ grow~h· curves ar.e ~~r~ve~." wotild .

. · ·.,be. ·the structure .from whi~h· the f~w~st agi~g ·~rrors ~re l.ikei.Y . . . ' . . I ' . . .

. I . .

tq be made and consequently most mea,ni.ngful ta use in age. and

·growth studies •. Aging ~rrors i.n~cilv·~ · the ·addition or deleti~n of . . . ; . . . . . . \ .

annuli . to the age given by a s.tructu~e. They _also include pr?blems '~ . . . . . . . ' . ~ . . . ',

in ·measuring annuli,~determining · the ~.xa~t focus :or. position of I • •

'. annu.li , .. and distinguish'ing true armuli

1from false ch.ecks. Although

' ' • > • • I' ,·' ' ' • ' '

. it WaS not possible. to determine if eve~;j check \'laS a true ·or false . • . . . : I . .. .

annulus, ge·neral .measures we're employed to 'distinguis-h ·between ,, the . r'

two.. Wi.~<li, ams (1955) suggests that on scales ••a ··good criterion . for.

: reccfgriizing _a fa.lse annulus .is it~absence at the a~"terio~ or high ' 0 o ' o I . ,

anterolateral · fie1 ds since ·annuli usually are dis.tinct .h.ere ~whereas /' . . . .

. . . . .. . . , . I ·. . .

the false a.nnuli are not" . . on . the bony structures, false annuli. are

recognizable be~ause they_show 'an abrupt instead of 'a ,gradual change

or: fadi~g . out from ·th·e ~pague to -the thin t~ansparent zon·e·' (Frost

' I

1 .•

"'· . . . . . . . , arid Kipling :1959). · 'As growth. slows ·;n later years; this' ch.aracteristic

> ,' ' ' 'I I

i's: harde~ tq distingui.sh. · At · Lobstick, the ·problem of false annulus · I . . ,

fOrmation did not· appear too s~vere~ This may be1accounted for by ,, I ,' • ' ~- ' ' ' :: • " • '

... the. abrupt season~l changes in the area .and:the . r~latively littie ·

growth t~at occu·rs . .from the ti rre of a·nnu.l us fo~mati on until ·s p~wning ,

.~ .·

...

I . I .. , .

. ·:

· ' '

.' , • • • . J . . I

' • • . . • • . ,. - • . I' . . . . :. t , • ' •

·. occ1,1rs; ·· Any check mark la~d dpwn . durin"g ._spaw~ing · would probably be ·. ..

·indisti~guishable ·fro~ the tru~ annui·u; . . ' ·

· There is a high correlation b~tWeen ·the. length of each of· the .

ag~ng -struct.ur.es a_nd the length ~f :·th~· fis~ ·(Table 5), sugge~tin·g

. \ ·.

. . . . .

·­. . ~

. ·'

· . . .. ·:·:

. ~ ---.-..t-..:__:.._._....___L..--,----·-- ;,_ --·-- •oi •• ~. ' ... - .-----. ··---~- _ .... .. . _.,---· -·-- --·--·- . .. ,.. .. __, . ... ...... .. -.. ~ . . - ., / .

-:

:'I

'.

p

'

·• ~··

. i /

'

; ~

'

~ .

' ! I . I I ! 1 !

.. i l

'

. ,.

. ·.. ·. . . . . .· . ' . \ . . - . ·. . ·.. . ... ' _';

• .. . ,. , _..' .. •· ••--· ·-.;:.,. ~:'"'"·: ' "' •· ~· ~:·-- ·•--:~ .', · -~· ~~-~-~··• , • .,.,;..~·· ·, :~'>"rJ-'1'~"''·'' ",'1'";':;..,~ ,·,_~ .• ,m • .• ~.~~_,...,,, "'" 'T' -· ,' ~ ----· .... \. ,' . ..

;' ..

.·.

'/•

·' ·

. .

. I /

. \. ' . \

! \

__ .66 - "1 .

' · . . : . I . . . . I '

' that all . four aging· structures accurately reflect the growth of ·. ' , I , '

<j I ~ \

the fish . . Curvilinear relationships e'~ist, ·.although the,re is

little difference between correlation coefficients for linear . . . '. ' . - \' . . '

and curvilinear· regressions. ·overall res~lts ·would :have been -q,,

.similar if 1i,near body: aging· structure relationships had been · ' · , . . . • • . I . , .

··used. Where curvilinear body: agir)g $truct'ure ·relationships ,' I I • 1 Jo) I exist, the length of-th~ ~gi~g s·tructlire usually follm·JS the ' ·

/'..growth pattem. ot:_ .the fish, . ~ncreasjng ·more ~-lowly as .the fish

-~ grows 'older. This is true for the body: scale_ length (Fig. 6-).'. ·

'· ·and body-: opercular le~gth (F.ig~ 7)' ·relationship{ but ·not so for

_.1 the body: cl.ei.t,hral (Fig. 8) . or body: otolith (Pig~ 9) relation­

ships. Neither cleithral nor otolith gro~th is reduf:ed with .. _.

increased · f ish ' length;. the increase in otolith length ·is more .. .. -

rap~d relative to fish }ength th-;ougho,ut the early life history

· (0-50 em) .and is .rel 'atively p~p~rtional'_t~ ·, fi~h . length in the ~ • ' \. • ' • I

·latter stages (50-90 cmh This is difficult to ·explain in . ·....---..._ '

relati'on to -t~,e ''reduc,tion -of .growth exhibfted ' by scal~ii- and : ' r ' ' ' •*' ' - .

opercula. ·

Analyses ·. o(covariance were used to test for st~tistical ' . < /'" • . . r

di~ferences betwt~~ the age-length r~gressjons derived from each . , ..

aging st~~cture··.

Empirical age-length . rel.~tionships for males" 'did not differ '

significa·ntly -fro.rri those for females, using any of .'the four . aging ' I " ' • i • ' ' •

. s~r\Jc~ures (Table _lO). All'male and .female back--calculated

·: age~ 1 ength rel ~·ti ohs~i ps \d~ ffere~ si gn~fic~ntly; th~ s 1 op_es

.· ..... .. · .• ;.-·

·-. · . ; . -

...

. ·-- ... ___ :._ ___ __:__·_. __ .. ___ ~ .. --- ; . - . . ' ' \

I ·.

\ ..

. ; ...

/

I ·.'

. .._

-}

! I

! J .'' I

! 1

. '

' .

·,

'.

J•

'

,, .· ' .

I .

. .._

I .

..

' .

. ~ .

. ;

I '

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' ' .

,• ' !

.. · . I ; , .· f ,

/ ··· ., differed _u·si.ng scales, the adjusted ineans using' qper.cula, cleith'ra . . ' .. ~ . .

. . and otoliths .. · T~e di-fferences in adjus.ted .means may b~ partly .. ·

· · du~ 'to· an -i!)~uffic_ient sample 'of small .fi?h -which 1~~ to·.

·.-.. difference~, .betwe-en males %nd female~, -in ~~e ~verage length~ of . :.·

o'percul'~, clt~ithra and -otoliths -at annuli .I and II.. · The d_ifference

;'~ - ~hese ··~~hen fitted.in- the app.ropriate.,body.:' _aging s·~ru~ture . . . . . . . ' .

· · · regress i-011, was· s uffi dent to · significantly, affect the predicted . . . . ' .. . .

adjusted ·means. : .

Differe-nces oc~ur· beb1een el!Jpirical and back..:calcul'ated age-. . . . . . . ' ., ' \ . . ·• ·_ .

length . regressions ·.!Jsing scales, opercula . andcl~it})r.a (Table ·ll); ·

. there was no· differ:enc~ ·using ·otoliths. '. Comparison _Of1 empirica·l . \ . . . .. . ,

·, '

~ge-len~th regre-ssions . shows no difference i~ slopes or' _q.djusted

mea~s 'between. any· of th~- ··four agin.g methods (Table .. 12). · Given -this

similarity betwee'n empiricar age~le~gth regressions_ d~ _rive~-from ' • • ' • • 1 ' ~ • -

' I ' •

all aging' methods and the high. correlation. betWeen th~ length of

each aging .structur~ and.· fish fork length. (Table 5), .thi~ suggests ·-

that the otolith method,: for which there are no empirical and back- · . ' ' . . ,' ' ' .

~alc~l~ted differe~ces, is ,nq~~ , reliable in · assess.ing ·ag.e ·and growth ... • I : •' ' ' • • • ' • ' ' '

I , . . .

of northern 'pike from Lobstick. The difference in slopes between . , . . . . . , . r

· empirica.l and back-calculated age-lengtn regressions, using scales, . ~ . . ' . . . . -

opercula_, and ·cleithra· ;·~·ag.ges.ts t~at ·ag-Ing e~rors have b~en made ~

T~ese err~~s cpuld hav~ be~n made in reading .the ages .or mea~uri~g annuli from the particula~ structure. ·Most problems involved either

} ' . . ' . . .

the first _ fe~ or last fe~l an!'JUli on t~e struct~re .. . Identification • • • • • • It • . .'

of the first ~ncf second annuli_ on _opercula wa~ often d1.fficult. Th-is

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. problem· has be.en documented by F~ost and Kiplin·g (1959)'"who ·suggest · . . ' · ··

.·. that the first _ and second ·a~n!;J_l ·i are. oftEln ·obscured by the g~wth . .

-.: of spongy tissue at ·the base of the operculum. For scales~· the i

' . problem: involved .measuring ·. the fi~st few annul;, the .delineation . . ~ .. . .

. '

_· of ·which were often ·unclear. \ , .

/

These. prob 1 ems become evl_f_:,nt . in the .

back-calculation of l'eng~hs ·at .agel {11) • . Scale, o'percular and

cleithral back-calcu~atfoni give larger resul~s fo,r_ i.l; , the. results . ~ . . ' . . .

for .. ·otol i ths are more c~mparable. with elJ)pirical';:·results' than are: ~ny ' .· . . \ : . \ .. . . . ~

of the other three methods. · Problem's also exist in identifying the .. -. .· ~ . . .

l_ast· few annuli m1 scales of older' fish. · The slow growth of· older • • I '

fish makes it ~ifficuH . . to di,s ti ngui sh annuli .and. measure _i n·c:rements

, of-growth -o~ the scale. - This becomes ·evident ~Jheh ~~~paring gr~th

curves generated from back-calculations of.scale . measurernents to .

. · ~ the other methods; back-calculated fork lengths at. the older ages

tend to be smaller ' than those derived ' frorri othe~ aging str~ctures •. • ' l"• ~ • • •

l~hen comparing 'the n~mber ~f zone~ .in scal~s and op~rcularb~nes - of ·' • ' , • , • • • • L '. ' \ • •' ' , •

.roa.ch, Hansen (1978) .found there' were fewer zones in scales from

fish older than 7 years. Similarly, for muskellunge, ·Harrison and '. . . . .

· Hadley (1979) . foun·d that · fis·h olde.r than 9 years could .riot be ·.aged . '

. fror:n scales, bu~ cleithra. were useful 'for fish· a's old as .16 years. . ' .

·,.· . · . Comparison. of emp·i rica 1 age:..l.en·gth regressions showed · no

di ffer.ence· between . any of the aging methods . (Table ·12) ~- · · Back-: - . . ,. . ': . ·. ' . . ' . .

..../. .

_ calc.ulah~d regre~sions of any 'aging method d_i.ffered signtficantly'

. ·· _. .; \ from tHbse of any· other m~th.od \·lith one: e~ceptio~-; . the regressions . •. . .. ,·,

for femal~s from otoliths ~nd scale's {.Table :13). ~Ji 'th the exception .. ..

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of the · regressions fr9m otol iths• and scales, sexes separated and

. combined; all ' other· c~mparisons of 'back-calcu-lated 'age-l~ngth . \ ,,

regressi~ns di~fe~ed vary si.gni_fica9t!Y· ·both in ~slopes an~ ·~ .

adjusted means. If otolith back-calcu'Jated age-length relationships

are accepted as _·standard~· ~n~· ~omp~ri;ons ~re made. to the~, then

operculr.r arid _clei.thral . relationships. bo~-Jl"predict too ·large . . ': . ,.. . .- .

lengths: at younger ages. ·This· could be ~xplained if the first ·and/ . . . ( ( . . . . . . . . . . . . '

or ~ec~n'd ann~li we_re 'obscured and not read from 'sC>Jne of 'the ' op~rcula . "'. ;

. . and ·tleithra. ·. ·.Th.is' w'ould i·ncrease the values of the average .lengths - . . . . ' . ' - . ' , . . , . .

·. at annuli I and II ~nd .cmiseque~tly .increase the .predicted _fork

...

lengths .at ?ges·~ 1. and ~ in the appropriate body: . aging structure /

·regression. · Although .this pr~·blem has been .docomented for .opefcula ·

, .. . {Frost and. Kfpling ·,.9~9; .. Ha~sen 1978), i:t has t:JO~b~~n documented , ;· .·. ·. . ~ ·· · , \. . . . - .. . ·...._ .. .

for the . cle,ithra of pike:(Casselman 1974). or. muskellunge .(~arrison-

and .Hadley· l979): . . . '

/ .The relative .sill!ilarity between age-length regres·sions 'derived

I .'.

. . . from . seale~ . and otol fths must b~ c:onsi.dered in choos1n9· a meth~ .

for age and growth ,. asses_srren'is ~ There are no statistical . . . ,

differ~nces ~. in the' a~just~d-. means .pr~dicte.d b~ scales ~ and otcili.ths, . . .. - ' ~~ . .

for 'sexes separated' orcombined. ih'e difference in .the .slopes~ . for . ' . . g} . . . . . •·. ·,

males and sexes . combined~ is: in the. earlier years, scales pr:-edictjng ·. ·' I " •• • ' '

. ; . . . . . ' ~- . . . . ·. · 1 / '

. larger' lengths than otoliths· from ages 1-to 6~ This · can be related . . . . . . '

· to the difficult,{ in delineatin.g ·and ~easu.ring the first few annuli ··

·c;>n some scales~

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· Ot9li.ths were ChQsen as the preferable method far the age

, ~ and growth stud~ of northern pike f;:oin Lobstick . . A ~ case could ' . . . . . . . . .. ·.. . .

. be presen.ted ·for the use ofscales based .i.Jpon .the · relative · .. . .

~imilarity of age-length '·relationships · derived from the two me_thods . . . ;, \ . ! '

and the ease of collection, _handling·and readi~g of · scales.-..

,(/

. . · · II. ·Biological studies ,I

' ' . . . ( ' . . : ., . . . The several methods used to sample norther.n pike from Lobstick ·

. \ ~ -: . '. . '( ' .

helped limit the. problem of.size selectivity of g~ars. Gillne.t

- s~l'ec~ion for -northern ·pi.k~is _ by size with~ lower.li~it'-~nly; ' I ' ' I

·an fi.sh' over a certain.si.ze are liable to capture (Kipling 1975). ' . . ' '. . ' . ' .

. ' I ' ' '

. Of/ the 415 northern pike· sampl~d. at Lobstick, 9% 07 fish)' we~e ·

gi)inetted. Th~ .fyke net,' a passive ·_ftshing -method, cQptur~-. . . . / ..

acti've. me"!bers \'titHin .a population; angling captures active and .· ~· ' , '"" . ' • ·. · .

/

· feeding fish. :''Fyke nets. accounted -for 29% (12.0 f ish) and angling · . . ' ' ' . . . . . . ·' ' ..... ··

. . · . ·,· . I •

56% (232. f1'sh') ·or. the sample~ The seine was · used to capture · ,

. conc;ent'rations of pike i:n shallow w'ater during the spawning season

_·and a~~oun~e-d. for·. 4.%· (n fish) . o; .. ~~ ~a~ple :: The pl~xigl'as.s trap

1 ..

. was ' used i.n.:shallaw ~at.er ' (< 0.'5 in) to obtain a ' sampl~ of the smaller ... r ' , .

size rang'es of pike_. ·. It ·captured pike ra_nging in s ize fro~ · 9.3 tci \ . ._ .

( 1'' . ' -~

-· 51.0 ~in and· accounted for 2% (9 fish) of the sample. · .. . . l .• , ~

In all fish · bio-logy studies, a· representati_ve ·sample ·of·. size :.· . . . . ' . . . . .. . .

.[ ·.

· ranges of the · pop·uJ _ati~n is required to. study age anp growth, : .. ~ . .

· fecundity.' a~d '-_food habits. Based upon sample ·size· and number-arid . /. ' '

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types of gears us.ed, 'the. s'ample of. larg~r length. classes (50- .' ' . ' ·. ·. . ' . . . . .. . ' · . .

. ! • '

90. em) appears· to be representative ·for th~ northern p.ike ·populatio11 . ·=· ·. · . ·,.,., ..

/ • - ~ # _ .

· . at Lobstick. The small sa.mple size of' fish. 0 ·to 50 i:m .probably . ·:· · . . · . . ·. ' ' . . . . .. ~ .

doe~ not trul~ rep-~sent th~ ·population but is" due~~· sampling ·

techrdques. Of th~ 'five gears~ thti plexi.gla~s trap. was ' the ~nly -· . l . '

' one capabl~of . being used in .. th~ h.abitat of th~se . fish . . S~ining · ~ . . . '

was i neffet;ti ~e due to submerged. b~shes and vegetati C?O" in the .

flooded · ba&kwaters; · :Other sampli.ng ·methods \'lere cons.1dered; however, . . . . . . . . . . .

suHable el,ectrofishing gear was not :availa.ble and~-rot.enone

pois~nin'g co~ld not be. u~ed · d~e :to fe~'eral gove·rmnen:t: ·polfcy

. restricting 'its us·~ . . Acknowledging 'the limitations imposed by . the .. . ' •, . . . •'

· sampring ~ethod~logy, the followi~'g , dis.cuss:i~n .. considers . . in~ biology, · . . ' . ., . , : . . . . .\' ·. . ., : . ': . . . . . ' . '. ' . ~ ...

·. of northern pike ~rom Lobs~·ick in·.relatio.n to the ~iology ·Of northern

pike from other parts .. of ·its c~nadian range. -· · ' • \ t • - •

·,The Smalh10od Reservoir. and ~ele~se gat~ · ~~ Lobstick create . ~ /. unique . en vi romrent ·for. all · fish. species.-. below the · Structure~ , The· . · · ·

,• 1:. · lo • • •• , • • , · . ' · • • • ' • •

·, ~tructure . act.s as a' barrier .. to-:upstream ,migration of al J_; speci~~ .. but'

al · l~ast tWo species·, : lake trout and pl"ook trout, can su~vive . . ~ . . . ' ' . ... . . ' ! . • • • : t' . • '

passage through the ·structure (Bruce Linp.ubl ished data). This one.- ~ ' ... . . . . /: . . .· . . . ' ' . .. · . ' __ ._ . ' -:- '

way'.movement of fish may help e;plai~ the large concentrations of • : ' ' . • • • . • ·. • ' . . : v' ' ~ . . .

fish immedicd:ely below·· the structure.·. The rate of water :·flow ',' . ' . ' ' . .. . ' . -~ . , , .. I

. through Lobs~ick varies throughout ·th1:1 .year. ~ .. This causes flu~tuating (I' . . ·. ' . . . ·. ' . ' . . . . . . ' .• · ..

water levels which affect both the spawni-ng· and .rearin~ areas • • ' ' ' • ' ' • • ' • • ' I • ' '~

·:·available to ~·mast ·fish species .' The.:·effects, ~f the · l.arge. / . ... \ ', . ' . . . . . '

: . con'centratio'ns ot' fis~--and· .. nuctuating water':levelso on ,the b1ology ' :· • (I • , I ' ' ', 6 0 - ' •

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: of n~rthern _pike .f_r.om lobstick ~till be· considered- more clo~ely . f

. .

· through_out .btne · discl!ssion .... '.~· . , · · •

Sfmilar··to othe.r unexploited .. fish, p.op~lations .in~·orthem . '' ' I •

":?, .·

' ! ' · !

. ,,-

:_ iakes"' (Johnson 1976; .Po~er . l978), the northern p.ike from · ~obs-tick ' f • • • ' • '•' • • II '

,' .. . ·.:_. ~ e~hibit ·large·· meari l~ngths ·arid:·.weights< whic.h cluster iiro.und·.·a modal I .· . . . . . . . . . . . .. .

! · · .. . valu~ (Tables 14·and TS) ·. ~ . Ttlis-is nat~r~l for.· a pisc1vorous species,

•· ; .... I :.n - ~hi c~. ·a:s ·i ;t i.ncrea~¢s .. in.~i.ze ·, _ha~· fe~e~ ~~urai p_re.ciators ' . .. There . . I ,

• .. • • • \) • • • .' : • V"

. ,

is little fishing mortality; ·therefone, most removals from . the 1• • : ; j . . ; · I

I ' 'j • • • ~ ,

. population are due to natura 1 morta 1 ity. ·• I .

4• • • • • , . ' · • • J' b

· ,;·· . · . f:stimatfS·\-ie're made of the inst1antJln'e'ous tot.al mo,rtality -rate

~ I

.. . . _· . . ··(t:) · for ·~.a;+ ~n~ fe~a~e~· (F'i g. ,··7) .· -Th~ .1imitatJ ons .of su~h .. · · I . /.- -. . j . . · . esti rna tes• -in'{s t be co~ s l 11; red be fo '1' any conCl uS i _ons can bO ~de: ·

I, e[ · . ::::;;: :~t~l;,·f:~~f:~:i:r::: :::::h:h~n:~ -:~r:::a::~::~oin ~ ..

· j

f ~ .. quest 1 on; :2 f there has been n~ eh an9e fn _mo:ta 1 1 tY , .. ~· ~ith't; me . ·, I I . ' '' . ' • ' ' . ' ' " - ' . ' •, 1 · • f: • 3) the · sampl. e is ta~en' randqmly .from· the :age groups involVed," and

~ ' ' t ..... - .. ·. ~· ·,·\· 4) the ·~ge "g;~ti.ps i~ :ciuesti~n \.,ere'· equa( in 'nu~bers at th·e. time : eiU:~. I . . . [ .. '. ·. . ' . ' . . . . • .: . :· o • - ·. . . . . . .. . - - • .

• · I • .I . • . \'laS rec~uited , to 1 tfl~ popu)_ation being :~·ample,d (B~rano.v 1918). ... ···: ..

·s~~v-ival .... atd/o~ ino~tal ity · ra~ 'rna; 'differ-· w1- ~h age, the. p ;{ke 'havir:rg· · ; •• • ' . . ' • l • • ' • -~ . • • • · : • • - • • :: • ' . :.. .. 'i).. •

' ~ewer predators a~ ·it i~cr~ _in· size . . · Also, ·· the sqmpl~ ·of pi.ke. : .: _ · I .. • . · . . : . . . . . . : . . · .. ! . , _,-·. t .. . . . . , ·. . . . . , . .

~ . : . : :c .. ~ ; .

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' ' . ' =~ . 1 • ·fis.Qm lobstick. is .not repres~tative Of. the population .as . the younger . :Y.,' \

·.- .. ·... . :a~e :group~ . . a~~ . p6orfy r~p~~·~~~; · · .How~v~·~: . o~·ly . the . des~:nd·i-~g! . - , . \ . ; :' ) _·, . ' . . \ ' ' ~ . . . . ·.. . ~

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·._· · .. , poi~t·~ ·.of :the. ca:tch . ~urv~·. we~e - used to estima.te 1.l 1 and -qv.er this :. : • • • : ~ l • • • .. • ' : .. ·: • • • • • • • • • • i .. ~ . . . ' .. ' .; Q •

·I, , ~ \ 14 ; 1:: · •.

' .

... ·

. ' ·: ·.' range of -~€)e gtoflps, sur_vfv,al cand: mort·a'lity rates are' likely tp be . ' ' • ' ' ' • " '' ' ' ' ' ' . ' ' ' ' ' ' r'

. ' • , ,, ., I

. . . ; .-· . ::: ·~: . ... , .

' :· · ~ ·: ,: '' ," . ·;_.·· ~· · .. uniform and ·the sample is . re'i>·resentative.·'. Littl~· i's·'known 'concerning ' ' '.'J • • ;,, \ , ' .. .... , • t ' .. ~ • : .• .' ' ' ' : : ' ~ , : • . • '. •I : • : ' • , ' 1 ' ; ' ' .. , ' O . .. • • .. : • ... :

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-~ ' .

.;) . . ~: '

. I

' ·:··! '. .,

73.-

.. .

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~ ,'

, . ,··

'~or·t~l,ity_ rate over till)e · ·,&9d·r~crUitment_ str'ength of age gr~ups _ of

nor~her.n pik"e f~~ lobstick . . Therefor~~ - con~lu~i.~ns cohcerning .

- •,

'. ' ',_ :', • • ' ' ' ' I • ' 'j

rnagn,itude 9f the estimates_ of ··z·. would be unr.eliabie; hOV{ever,. ·. 0

'

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.comparison's' can be ma~e betvleen the values derived for males and · .. , , , ' C , f I , 1 , ' ' '

' - ... . , ' ' I U ' , , ' , : • • • · • '

fema'les .: Since the instantaneous fishing mortalitY'. (F) ·is low;··· . ' . . .~ · · . ...,;' ...

'the instantaneo~s total mortal i, ty (t) .can ~~ us~d as. an estimate ' . ...- '

•'of th~- i.nstantaneous' nc(itura.l mort~lity ' (,M) i}S _· z'-= F. + M. ~-T~~ ' .. ' . ·. ' . . . . .' ' . /. ' ' - ' ' .· ; .. . . .

· est·imate --of· Z for rnales is 0;32, for females 0.37, suggesting a • • • ,f • ; •

higher natural 1)iortal ity ·rate. for .. femal e·s :" ·These differences~ ' ' 0 • I • ' • o ' '

if biologically --real, ,nia; be .rel a·ted. to th~ ene~g~tic~ -~t ' . . ·.: · .. ; I , ' , ' '

.. 14: • .

reproduction, .. the female·.gonad~ being large!" than . the male1-s and · . ' ' . . . . . ' .

r~q.uiring 'more: energy. for deve_l,opm.ent: Medfor~· and 'Mack:~Y (i 978)

found · that' ·matu;e ·ovar1es o/pi ke c~ntai ned - 1~4. stimes more protein . ; ~ '\. ' .

and 1.0.5 times mor.e _Jipi d than mature· teste.s-: Diana a~d l~ackay : . ' . . ' l' :\'. ' ~· ' '' -., ' " ' . ' ' . '.

(1979) -found that testicular~rowth-· occ:urred entirely in August· '.- ' . .-] ' ' ' ' . ' ' ' . : ' ' ' ' - ' ':' ' '

. of each year-. Q.vary calorfc growth'began iri, A'ugust ·and· nearly all : : ' ' -~ : ' . ' . ' ' ._.. ' . # .. · ' ' ' _. ' ovar1an growt~ '(81%) octl!_r:re.d= from. Oc.tobe,r: to M~r~h : .. -No gonad . . ' . . ,. .

_growth occurred from March. -t~ May, : ~et . as· mu.ch . as o68% of. the total .. ' ' .

liver e~ergy was .. used. d-~ring ~pawning, ·s~ggest1ng :that· thes~ . : . . : . . . . ' .

de.p}e~ions. were ' mainly due to spawning r~lated ~Ctivi ties, r 'ather ·. . ·. . ·~ . . , . . . . . . . . . . . . .

·than · gonad growtfL The ·s-tre,ss .Phced o'h femal.es ·_~ue · to ovarian · · • .. • • · , ' J:l ,.. • • :

• • \ 1 ' • ~ • : : ,i . . . . '.

development during : th~: winter and sprin·~·~a.v. contrib~~ to their:' •• 0 • • • • • • •

. :higher natural mortal_ity rate. ,, .. · I ' • <

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/

- 74 ·-

·: ·

: ' ' . . ·.

' . . .

. . '

Field''observations at Lobstick corroborated the· find1ngs of .. '•• ' ·. . ' . . . . .. , I , , ' , , .·· , , . . . to·· • ;. . • •

Sva·rdson. (1947) \'fhO suggested, base~ .. on· evidence from marking .~ ' ' , , ' ' I • , ' I

,• .-f( ': • . .: •

experiment_s, that pike ·do, not necessarily spaw~ each year~ : ... . ' ..

Seve~al · ovari~~ co·n.tained.large ~ggs ·(>.1 mm) retained :froni .a . . · ~ :. . . . . . . . . . ~ : . .

previous .ye.~r;.s :spawning· 'andjmmatur~. eggs .'{< ' l\uil') which ' .w~uld " . . . • . . . : (~

• , r I :

not · b~ ready ._for r~lease un.til <th~ . following ye~~- This may · .. · . . . . . . . . . .

~ /' · ' . r .

i alsp. be related to the. rate of gonad development . .. Growth data,

• • • .. • • ' ~ J • • • • • • • • • ' • • • • • /' • • -

to be . ~i·scuss-ed later~ suggest that food av~i'lable · ·to pi'ke at I ·.1

i ·r /- ·

i·.' . i

' . / ( . . . ' .

' - · . ' f, . Lob~tiek is- abundant.:- ·However; most growtr o·ccurs .d~ring, . th.e

. surrmer when the~e a~~ · large concelltrations ' of whitefish beldw ) ..

' 1 •• •

, I . ., ·.' .. -1 . •' .. ~ .~:: .. · : ·. • ' . . ' .' ' .. )·

1 .

l r

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· · lobs•tick and water temperatures are"'-relatively high ·~ Nothing is · • • . •• ' ' ... .... • "l •

. . . : ·; . kno~n of food . availability at Lot?stick ·du.ring winter . . In Lat 'Ste .• . "l.J ..

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. : :·. Jfnne, Alberta,_._ energy jiCCURJUlation o~curs in both sexes during·

. · ~inter and s'umrner,· about '35% of pike growth .·occurr:-ing in ' the • ' ' \ ' • I ' ' ' ' ' .,. ' ' • ..., '

· w.inter "'at a temper~ture of -. 1. c.· . Ovarian .growth~ 11hich occurs ,.. . . ~ - . '

·'during the ·winter, must result from ·· food ·intake·, as there is no ·

. • · ~epletion ~f soma~ic _en~rgy ~U.ing thiS t1.(Dianaand Mackay •

·1979). ' Z.f developme_nt of -t!Je ovaries :is si._owed during wint~r- and ·

. early ··sP,ring,- sp~wning.' maY bt{ delayed t~. the tdllowi~g y~a~· unti'.l . ' ' '. . ' . .. l

gonad development 'is . complete. and .·sufffcient so~ tic energy ..

··1 rese~vtts a r~·· a~cumul -~ t~d'. · . _ · " · . .' : . . . .. "" · .. J ' ' • I "• '

Common with· · ~t~~~ .\rik~ . p~pul~tions {MH1~r · an_d.Kennedy 'H48;! .·. : : : Frost and Kipling )96J; ~~lfert and Miller 1978}~ lobs~ick)ike ·. ·.

exhib) t great ranges · ·in~:{el1gth and weight at ·ea'ch. age (Tabl~s· 9 . . . . . ' ( . ' . . .. . .

, . , ·and 20)~ , This. suggests that 'there ·are large .. differences in · . ' . . . ' . .. ' . '• ·. . . . ·, .. . . . . -: '!

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·growth rate within and '_possibly betwe~nyear-classe~: Differences

within ·ye~r-classes may be partly . e'xplain~d by natu,ra'l ~ar1ations . .. . / . 1 .

between indi:.viduals ·which : wo.uld .affect' ~uc.ti paramet'ers .. as gonad . . . . .. . . . . :_ : ; .· r . .. " : . . -·. . . I

·. weight, whole weigh~ .and fork :length . . Differing -environmental

· · co~ditio·n~ such as. wate~ temperatures and fluctuating, wetter levels 1: , • ,<" f ' ' • , • 1 '

1

>, "' / ', ,

· ._ ·could. cause differences ·in gr~wth · . ~ates between yea·r~cl asses:.

·Prey _are ·e:oncen'trate~ into s·maller areas ~t· times -of low .water : ' . . . - . . ,r ' •

J ·:

makfng them more easily available to .. the; pike . . The· ra.ndcimn·ess .of : . . . ·. . .. • I · ,

the'se nuctua:tions from"year to year 'coul.d - ~ause differ-ential . ' • • ,I • • ' II> • • ' ' ' ' ' ( v ... . I • •

gr~wt~ : rates · be.tween yea~~crasse~~ . . Frosf-and Ki_pl ing ( i 967) ~uggest -. ·•

/ · . ·.·

\

'/ '. ,".

.. - ~

· that· variation ·in .growth of different year.:.cla~ses is .correL1.ted · .· · . . . . , . .'. . . . . . . - :: . . . . . ." . . , - - .. . . I / . . .

(_ . . , .with .yearl.Y temperature· variation.s·, pike in . .the year-classes · . . ' . . . .. . ! .. ' · . . . . . . . . .·. : ' • ·. . · . .

~wh,ictl ·experienced highest :cumulatjve tempe.ratures ."bfling about s ··cm. · • j • • • •

,.. ··: · . ·:·longer at age 4 years" than .· those whi.ch experienced the lowe~t . .. ' ' • ' ' i ' o /' •• ' • ' I . \ . . . l ' . . -tempet:'ature resime . ., . /' '

· . · .·.·· Thej•lc.~la~Q fork lengths _of th .. · d~ffererit a9e ~;~ups o~ pike

~ . , -from lobli~.=k can be compared with those of other labrador populations

. . . . :of pi~~ (T~~l ·e 19.) ~ · . Calc~lat~d 'length~ of ~~der · fi~~ ··a~ larg~r .fo~ : .. ' : . • I ' ' : .. fJ • . . ' ' ·• , . ' ' ~ . ~ ' •

i. ,.

Lobstick pike tha·n . for other labrador pike~ ·· As stated el.rl i er, this . ·. . . . . . . . . . ·:..-. . . .. . . ~~~ - . . . . ~ . ... . . . . . . . . .. ... '

""may .. part1Y. be explained' by' proble·ms i'n .measuring\ .annular. growth on .. , . . . . ~· . . ~ . . . " . . ·. · .' · .. . · . . . : _ ·· ··:_scales o~ older. fish. ·However, 1 t also s~ggests tl)at_ food~upply

~ · 'a~aila~le ~o pike at Lobstick · is ' cior:eabundaritthanf.or .the>: ~th·~j ·-·, /

. - -~~_ra~or ·popul_atfons, ~i:nce growtti of· the. p_l d'er fi.sh does. nbt detrea~e

-~ . as . rapidly. ' '. Jhis. s ugges ti on' is _s ~pp~:rted :by. the. abundance. ~f . . ·, . ·' ·

.. ; . ~ ·. ' · , . .

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_ ~hitefis·h below· Lobstick, str.ucture during the siJmm~r. Ana lysis ·. • . " . : ~ . ·1. . ~- : . : . . . .... . ' . . ~ ~ ~ ' ' . . •. . - • . . ' . . . . - .

of food habits . (TaQl~ ·28}-shows that a~ ·pik~crease in size, ·

·._ their'. _ di~t -cons- is~s mostly of_ whit i~ish._ . · ·~h~~~sh\~as the only

· food found in· fi.sh over 70 em. · · · ""

. I

' . > ~he growth r~te of lobstick .. ike is' similar ·.to that ~-(pike ' • ' ' ' ' ' ' ' ' I • ' ' • \. / • ' \ '

.in other northern·· canadi_an . Lakes (Mjl ler and~:Kennedy 1948) . · · . .. . . . . . ) I. . . . .

These relatively unexploited pop lati'oris are char~cterized by sl~w . ' . - .· , ' . . . . · ' . ' . - ' -.

·growth _ rates, - ~ nigh .age at first : maturit~, andl:(mg_ life 'span,. I~ . . , • ... ,'. I

·contrast, mor.e southern populat-ions. such as -those in Lake Ontario ... '

(Wolfert' aod Mi ller,·; l ~78) exhibit ,fa'ster gr'awth, lower age at · • j , o • I

•' , . '

· first ·matur:i.tY- ~~d shorte~ life span. Jhese differences· a.re · . : • • . . . , . ·. . ·. . . . . .· ; • . O't • ' . . .

prob~bl:Y due both to differences in climate ·and exploita~_iori rate ·. • The length attained by: fish.inmost north~~ri Canadian · l~-kes. in · ten {. - ~ \ , - . . '

YE!a;s 1·~ ~rea.ched hy . Lake o11fa:~io · pfke .in iess than . thre~ year~. the _.

fas~~ - growth. b~ing related t~ w~rmer ·water t~mperatures. · Als·o~ the . ,' I ~ ', • : ' I \ ' ' • _.

high·e·r _r~W.o.f ex'ploi tation ·;n· ·~ake· ~n;tario ,reduc.es · 'the . . numbe~s ~f 1.. . pfke present; • . decr~ases the cornpeti tion: for resources and thus : 1 eads

• ; ' t ' • • ' •,' ' ' I .. ~ ,' /:10 ' ' ,. . ' ' ' ~

to an increased growth rate. The · faster gro\'Jth rate aHow_s the . . . · ~ . . . .· ' ~ . .

.. 'J. , ,

/ ; ' .

' f ' ' ' ' ' ' • ' ' /' ~ ~ • • ' ' I •

. · pike to ·r-each the ·si ze at· which it will first spawn at an earlier . . . ·. . . . . . ·, . . . . . . . ~ . . . . . . ' ~ . . . .

age (Fros1t ~nd · Kipling 1B67Y. ~ Lolist~~k~ pike · are apr~doniina.ntly · (50%f \ -. . . . .· ' . . .

~ mature-, at age six, Lake Onta'rio pike ·at.· age th~ee. -'The · maximum age . 9 . . . ·. . . . . ,.

· of pike sa~pled .at Lo.bsW:·~ - .was ff- t"teen'-yea~ • . 1~ ·lak~ Onta;f.:fo t e{n· ·· · ..

· years,- · .. the red~ced lite sp£n ·:1n Lake . Ontari-o . p~oba~ly b~ing · due ~o . -,,_ ' • . l .. -~

the riite ·of exploitation. . . ' . ,. :

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Fecundity, . the nuilber ·of mature eggs per fema 1 e , i ncrea~es • ' ' > I ' '

· with size of pike (-Carb.ine· 1944; Frost and Kipling 1967). The \ . . . . ~

• I , I ·

. . s~ope ··~.f. ~he length-fetundi ty 'regressi_orr is ~ useful comparison ' ' ~ . . • I· . ' I .

·: of the rate .of 'increase of fecundity . between populations. - The . 6 • ' ' • .. ' • ' ' ' • • , • • • • • •

slope : ~f :this . regre.ssi_on for Lo~sti~k:' p)~e is: l~rge (3.1l) . · . • ' , ' , . I .

·compared to other populations, ~.16 for Gilbert lake., lii'scons.in . . . ' ' ) , , . I . . ' , ' . • ·, . . .

(Priegei arid Krohn 1~75) and 3.56 for the River Stour,'. England· . . • . . . I . . .

(Mann. 1976)·. Th'is .- ·large value may - ~e ·explained by the large ·' . . . 'I ' o ...

~iz~ at first ·.ma~·urity of .. f~male pike . _ at . Lobst~ck. .. Cl • '

The ra·nge of coef.fici~nt of conditiQ.Ti value.s for mature -pike . . . . . . . . . . . . . / . . . . . . . .

.from lobstick' {Table ·21) shows a trend ~award higher .values 'for ·

···females than for ·males. This ·can be explitine~ by th_e_.'larger '

· · size · cif · fem~le g~nads · ~s th~ ··condition val~e ·includes a whole . • • • ' ' ' 0 • •

weight measureme-nt for . each ftsh. · The observed drop in .the ·. · 1111 .. • ,

. coefficie~ts ' of condi.tion for ma.les and fe~ales. froin the . middle :

· to the eoo of June tFi g. · 1.6) corr.esponds wi,th t'he t _ime whe.n ·, ~.

spawning w~s I observed to 'occur. Spawning waul d. cause ··a decrease. ' • ' • 1\ ~ • '

· in wei-ght· in · bo~h · males and.'· .female~ which would be reflected in . ' . ..,:. . .

thei.r coeffi-ci.ent~ o.f con~i.tion .• , Water .. ten-Peratures .during ~i~ · ·

time (Fi.g. 4) rariged from ·2.·0 · tog_() C, \'lithi·n the range recorded

for. p.1ke spawning · H~ Wisc~nsi~ · ·(3.4-10.~ C) ~ (.Prie~el and .Krohn · · 1975). ·and Engl~n.d ·(s ~ o..:a.o c) (Fr,ost and Ki.plirig 1.967}. , .,

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Fabri"cus ··and Gus.tafson (1958)·. have 'shown -that stable or··ri~ing . · . • . • ' • ' • ~t • ._ ' "" ' , • • ' : ' o I o I : . ' : • : ~ .o • ," .. ,

' '

·' · wa.tfr l .~.ve.J: ~ s necessarY for t_ll~ :~ uccessfu~ .spawn.i~g of ·p~ ke~· ·. , . ... .. . .. , ·· ·

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- . ' \ Hassler. (1970) suggests .that ·rapid wate.r temperature fluctuations . . ' ' ' ' ' ' . .

. /..

. . . ' ~ . . . . . ' . . \ . ~ . .: ' and si.lt ·deposition·:may contribute-to.year.:.class failure of pike.·· · _ .. .. . . . . . . / · .. .. ' . .

: . • . • . l ·~ ' • . J • ' •

· At .Lobstick, ·rates of water flow and··consequently water levels

· f1 uctuated ~~ ~ ly durin~ the spawning Sf~S.On ( F~ g. 5) ~ •. Sh~ l ~ ~ ~ bays where Pl ke were found .concentrate~ · one d~y were dry the n~xt

I . ' . .

day· . . This was common throughput the spawning season· both ·i.n 1977 · . . . . ' ~ . ' . ' . ' '

•' . . .; ·. . . .. : . · , . ~

and_ 1978 and pre~umably; has _occurred ever sin~e- t~e. formati~n of

~he "smallwood Res~'.rv·o-1r.- in - ~~71 -.. Ove-~ · 7S% of the. fi:sh·._.sam~·l :ed . ·_

w_ere 'age seven-~rofder~ Although: gear .. sele.cti vity .ts : cer,tai nly ' '

.: ..

. ' a· factor? 'the small . sample . of yo:unger .'age groups may _not 'be' entirely~ ~ . ' . . • ·. '

' I ' ' \_ ' •

due · to the sampling. techni ql!ei fl .4ctuati ng wat~r. level~ ·during th'e ·. • . . . . .

spa~ming season since 1971 ma.y· ,have. r~duced the spawni,ng ~uc ess ·of ,· ~ -

·. pike-; 1 ~adi ng tq reduced. pop~i a ti ons ·of •the. younger age_ ·g;oup . . . . . . . ' · , ' . \ . ' '#·: . ' ' . ' ;,.

_ Pe·a~ spring · runoff occurs during June..in · the - Lob~tick area. ~ · ~-

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. . • • ' • \ • • #' I

~ Normally~ wa:ter .. l~~ls .would. be' .high;· f:i~tiding · b~ckwatE!~s ~nd ~rshes . ' . ,' ., . - . . ' . . - .. . . ' '

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•, < • I areas su'itable for pike spawning. '··control of tt.e' .rate of flow ' ', I . . ~ . •. . • · • • . . . • · • .. ' . .. .• ~'"' ~ . ·, . . . :- . ." • .' . , , • ·: . , ' . . • • n, ~

. thrqugh Lobstick ~tructure .a.fter:~ thi~ _pattern~ · del~yi ng _peak water · . ;.~:

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P' , :

: - In doci,lmetptq ng the pr~blems of age deternii~ation of northern · ' .

·, . · · pike, th{s' s 'tudy ·has. ans\lle-red some questions b'ut- has left; several'

· .. . :Get to be reso_Wed. · The;: ~n~f.wered ~ueStiDn~ arid th~ ,;,tio~ology ' , ' ' ; . to-_s.tudy them rna/form the basi~ of future research.·.;. . .. . _ ... , ...... __ ;. -·1

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'· The study involved the comparison of four me'~ho~s of age "' ' 1, I / • , ',' '! '

dete'rminatiori: · To obtain a: m9re .complete comparison of meth.ods~ .. ·· ! ' '.

' ottier str~'cture~ such as ~ertebrpe, fin· rays~ tret~pterygoid~; · . . I . . ,

· . ..

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... a.'nd teeth' could a'lso' be' included in· futu're work. -~ . ; . . . ~ ~ -

. : "The · ti~ co~strai~ts of the study ·prevent.ed ·analyses which : · · . . . .. ' . ..

•' '

recapture' experi·ment on -.a smal)er. pbp!J~ation of pike would . . · .. ; •.

elucidate some' :_0! the'res~l~s presen1fed 'in t!i'is paper~ 'tagged ... \ . . '

. fish, capturetl in fyke·. netS· once each year for four: or f:f.ve . . . I ' • .

. . . . '. .. ." . '• .• . ''

.! . · years, ·co~ld be measured, _weighed, and injected with tetracycli-ne . . ·. · · . e .. .. . . . . . . . . . . ' . ·. . . : . . , , : . . . .

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' sufficient sample of .tagged fish could be- tal<e'n from which ' the . , · . ~ ' (I • • .~ : • ~ t. . . . '

annual in_crement~ of gro.wth on eac.h of th~ bo')Y ~truct~res._ co~1~ ' • I ' • '

be de.ter!"i'~ed~ ·. Similar results .could be ·obtained for · scales •. :

Direct · com~ad~ons ~f .' a·gi~·g result~· ~ould ~hen be . ·ma~e. ·Such ··~·-·. . . . . l. , . . ~. . . . ~ .:~. . .. ·. : . . " . . . . -o o_, . . . . .

study would· help solve· · the' pr(lblem· of i.denti fying f~,l.se · annuli • ' • ' ' • I

• • • . ' • : "J.o;11r . . . ~ • .. . •• • • • • ' . ' ~ : i.1' . ·•· ... .

· .The tetracycline, ·i'f i~jected · at the same time each year, would · · .. ·,

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•.i . need to be cons i ~ered- The phenomenon ~f a 1 ternate ·year sp ·~ning r.'·

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. has ,beeJt · docti~ilted but i~ · not fully ._ understoo~. '- Questions · . : ... , .,. , . • . ' , . , . , , I . . . . - • ,

c~nc~rai ng' ~he p~y~iolOgica) mO~hanism and t"r.~uen~~ of occurren~e • •.. , j ·. , Wlttnn . ~ popul at1on need ~o .J;Je· -~ns.~ered. · In s~udytng the cnanl_s.~," .: . . . :I .

. the. av~Fa,bi'l i ~/of 'food fo~ ~ike d~·ri~g the wihte~ at 'lobs. ick. ma~ · · · t- ,: ' be cons i-O~red. : de~-Oed s_t u~ •: the .' paw,n1 "I su~.c~ss ofpite ; ~ ~ · :)

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: .. . may he-lp determine if' water lev.e] f-1 uctuatioris below · Lobsti-ck are .

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:aff.eet1ng .Ye&r7cl ~~s strength . . ·Consideration s~ould . be ·given . . " t() these· .·and other· probi _~IJ)~ b~fore···s:tp.ck :assessments · and sound;

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· In- the· 'suf!1Tlers of 1977 ·and 1978; a sample of 41.5 pike was· ·

take·n, by angling, gill.net, . fyke net, ·seine and ple:Xiglass .:·trap, . . ' / ·~ . . ' .. ' '· : . : . .

t'r·om. below ·Lobst.ick structure, · ·smallwood· Reservoir, Labrador.

..

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. Four ' me,thods of age det~~mrnati'OI''!, scal~s. ope'rcula, ' ·. . . . . . ·. . .. . . . ' -·· . . ,.,,.: .. . . cleit_hra and otoliths, w~re evaluated by comparing empirical and

, I ' back-cal.c;:ulated growth r"a.tes generated by .eac~~ .

I Analysis. of cova~ian~e.showed nci-sign.ific~nt difference ·~. ' ' . . ' '• , • I . . '

. ( . ' . . .

betw~em empirical and 'back-_calculated age-length regressions using. . . - ·I .

'otoli.ths; . there were differences using stales, .ope.rcula .ahd ' ' . I ' ' ' ' • . ' .

cle]thra. Otoli.ths were chosen for _the study of age an~ growth . , .

of n.orthern pike from Lobstfck •. .

No~~he_rn pike: from Lobstic i~· • . si'milar· .to · ~th.er' unexpJ~1 t.ed fish_' . • • . 0 1

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.populations in northern lakes, eJ<hibit lar.ge mean lengths (_62.0 c;m) • • # ' • ' • ( • • : • • • • • • • ~ • • •

and weights (1.~9 · ~g') which cluster ar.ound a _,~odal . .. val ~~ : ;·

.· T~~ growth rate o·f . Lobstic~ pike. is similar ·io th~t of pike • ' • I ., •

/ '

·in other northern · c~nadia·n 1akes -bu~1much slow~r th~n)n- ·m~!"e - · , • . . -·. . . . ·" . . .

southern waters. · J ·

I ( .• .. :, . . i· . ' · . · .Coril!On ~i th · other· pike ·popul ahons, lobstick P] ke exhibit · . ' k'· ..

,_.. · f! .. , ., .-.~ . igrea t :ranges in 1 ength and weight at each: ag~. · . . r· , .. ·. · ~~:-.: .... '· . Calculation~ -~·r mortality ' a11d survival, based upon a. catch.

. ~ ... :. · :· .'. ·-.. , · , dir.~~; s~~gest that: the ~i ~stantaneous tot~l. ~or~~li ty (~) ··fo~ . ' · ; / · • ' ' : fema 1~ (0,?7) 1" hi gh~r ;h~n ~~r lnal ~ (il. 32). · •. .

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Observation of ovaries· of mature pike ·fro!ll lobstfck show .!) - . '

· · that. all .. pike . do not spawn e·ac~ year : : , • · .. I . . . . . . f

_. The rate :·ofincrease of. fecundity \'lith re~1pec~' 'to. l_ength_ of

pike frpm Lobstick. is faster:: than ... that of otber more· souther~ · . . .

· popula~i o~s. . . . \

.~ ·· ~· Males ar:e predominantly. (50%) mature by age ·s~ or at 40.cm,' . . . ~ ' . ,"" . . ' . . -

females . by ~ge 8, , or at 6p em: For sexes . co~in~d,- the pike' are

oot entireiy mature until '75 criJ. / . ·. . . . .

Stomach ·analysis showed' that as p;ke grow, :their dfet becomes '• ' ' ' ' I • . • ' . '

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. entirely piscivorous.··and. consists mostlY of whitefish • f ' • •

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. . . LITERATURE CITED \ .

Astanin, L.P~ '19'47. · on· tne determination of .the .age a'f·· .. fi.shes ) . · .[in Russ~an, · Englr~h _su.rpll)ar~]. · .. to.91 ..• _th~· . ~6: 287...;~~8-~ : · .

·_ Baranov~ F. I. . 1918.' 0~ the .question o( the biological ba i~ of · · fisheri_es [in Russian] ... Nauchn. Iss led. Ikhtiologi cheski i

' · lnst~ Izv. 11: 81•128. . .. '.

Boya,r. H:C~ _ -and R'.A. Cli .ffo-rd . .. 1967 .. An autcim.atic device for . · counting dry fi~h eggs. T£ans. Am. · Fish. Soc. 96 :_ 361-363; . . . . ~ - .

Bruce~ H.J. -~ 1974;_ T~e limnology ·and ~ish popu1 ations ofdacopie .. Lake, West Forebay, Smallwood Reservoir, Labrado.r. F1sh. Mar.

Serv .• ~ech. Rep. Ser • . No. NEW/T-74-2 ·: . 74 p. ·· --... . .. 197~.' .. Experi-mental. gill~et fishing at:Lobstick. ahd -.·

Sandgirt La~~s, Smallwood Reser.vo.ir~ Western Labrador, 1974: Fish. ·Mar. Serv • .,InL Rep . Ser., .. No. NEW/1:-73-3: . 3~ p. ·:

. ) , . . \ . . · Bruce~~~4~J. · . and R.F/ Parsons . . 1979_. ·. Biology of the fishes of . , ·

Ossq~.ma.nuan Refervoir:~ . ~abrador, ~97o. F-ish .. ~~r_~- S~_rv. ~ech~ . _ · Rep. No. 836. . .. · . - ·- , .· --~-:;· -

·. • ,.r • J ." .. ~ .. · .-·:. · ." r1 ·

Carbine, 14.F. 1'944 . .. '[gg production ~f the· northern pike Esox . .. · •. :-1 ucius' L-: ,· anci 'the. percentage . s'urvi val ·of eggs' _and young on -

the ·~pa\·ming ground.s • . Pap •. Mi ·c~. Acao. ·Sci'. 29: 123-137.

· Casse1~ari',iM ... . ;l96.7.· Ag~ andgrowth "of no.rther~pike · Esox · · · · luci-us Linnaeus, 'of the upper st. ·Lawrence ·River. M;S. ·thesis,

Un,iv_. Guelph, Guelph, Ont~_ricr: · 2!9· p, . ·. · ·

----· ~ .. ~ · i974.- Ana lysis ·of· hard . tissue of pike· Esox ·1 uc.ius L • . with' spec'i~1 reference to age ·and .~rowth • . P. ·13-·27. In T.·B.· ~agenal (ed.) • . · ~geing o.f fish - Proceedings of an · in~~rnat.ional· symposium,. Reading, England, 19~20 July 1973. Unw1n Brothers Ltd., England. 2~4 p. . . :. . . . .

' /

. · ( I_n prep~ ration) ·. _. Clei thral m~thod of detenni ning .. age·_a!ld .growth C!fnorthern .Plke,.and _other esoci'ds.,. ·. ·

. .. , ' . . .

.Cass·e1ma!'\ •. ~.M. and H.H~ Ha.~vey • . 19i3.· Fis_h trapg~ ·of ~le~r ·~~~stic. · · Prog'. Fish Cult. 35:. 218-220 . .... ,.. · · • · .: ·

... ' • ' ' ' • ' ' I~ ' • '

I·._ Christensen~· J .. M. 1964 . .. __ Burning of ot~1 ith_s·, a techniqtje for. age " · . . · · det~tmi nation of so.l es a~d ottaer '.fi so. J. Coris'. Perm .. In~~ . . · . ~ · Ex-plo'r.· ·Mer . . 29: -7~-81·. _ . • . ... · ·.

,' : . ' ; • ' ' I ' ' 4. j' • • 0 ' • .,. ' I i' ~~ 't '

Ch.ugunova~ nJr: ·. 1959. -"Handb~ok fo~ th~ study. of age anq,grow·th Qf

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. .. .:-. ·.·f;shes •. Ak~demiya N~uryPress 11_ Mo~c~w. ' 164.p. , .. . . '

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· ·. deposition and -loss in th~- b~dy~ ·l:iver, and :gonads of ·norther.n "pike (Esox -lucius·_). ·- ,J. Fish .",,Res • . Board Can. · 36: 481-487. :1-.

• , I • --. , I ' • ' ' ·,' ' ' , • ' · ,;.. , · · ~ ' . "' , · .,' ,':

.. Dubois', A. and R.· lagueux ~' .1968. ,. Etu·de :.comparee de J'ftge ~calaire ' et de F[ge _ otcili.th ique - d~ .' la toul adi . (Sa 1 veli nus nama cu.sh),

Lac · Mistass i ni, Quebec. Natur.· ·can ~ 95: ·907-928. Trans ated by Fish. Res. Board Can. Transl~ . S~r. No. 2883]. · ·._:

Duthie,· H .:c. af!d M.t. Os·~~ sky ·.·_ ,~~74. . P.tankton; chemistry and ' · .physics of -- lakes .. iil t~e Churc~ill \ F ls .-region of labrador: .

J. Fi!ih _. Res_. Bo.~rd Can ~ 31! .·1109:...117. · · . ' ..

o Fabrfcus,. E.. ·and·- K.J.'Gustafs. n:-. ·1958 'l"Some new 'observations, on the · ' spawning bena·viour {)f.. th pike, · sox lucius ·L Rept. In st. ·

.'. · ·Freshwat. Res ;; Drottni~g~ lm 39: : 23-54. _ _ -· · · • • ' • •• • • • . • • • : ' ~ • , . . ~ • ~ 1 \ •

'-.ll.efrost; W.E~ and C. Kipling. 19 g· ·- The detennination of the\ age and · growth. of pike (Esox - 1ucius- L~-) from scales and opercul~rbones-. _._

11 - ~. _Con·s. _Pe_rm • .- Int. - Expl~_r.· -.:~r._ 24: 314-341. . · :. \ -

, -· .. " l967 .• A s'tt.£dy . . OJ repr.Oclucti _on,' eStl"'ly li.fe l \'JeightL . length relationship and ·growth of pike), Esox: lucius l., in · -l~inderme.re. · J. -Anim. Ecol. 36: 651:-693. _, _ ., · .-

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- . . :· . - (Ser. -z) 11(3): 50 p. _ ~ . - ·• · -.· . -_ -- !.\> . ... . . ,·, -. "' . ·_-· . . t: . . . , I . ·-. .: . .· .: . ; ·. ; _. . . . Hansen, _L.P. l.l 978. Age determinaUon -ofroach Rutilus_rutilus (L)' . :.~.:_:

··: - _'. from . scales and dpercular _ bones~ .-. Arch; Fischl~iss. 29: 93~98. '·

·. :·-Ha ~;~ s\)~--~ E. J;' an·d ·.W. F. · ~a:d·l ey .'. ~979·~ - A co.mpa-ri.son -of- -·~he - use.'~f: . · .j ·· . >,·. ·clei ~r_a to, tQ(r use of. ~c·a 1 es for· :age ·and g,rowth · studies~ - Trans •. /_·· _, · · ;';]

-!· ~ . -_-., _Am: Fish . _Soc. _108: 452-.4~6. :_-:- . · __ ... _ __ ... , . . . _ _. . · · · :~~ - - - : .. ; :-,-. : ._ ... Hassler, T .J ~ _1.97o·; Enviro~ment~-1 i.nfl u~~ces ' ori ea~ly development - ·::J -

· ., · · -.· · · - -.:'- ·, ~ ·,and. y~ar-c.l ass strength _of northern pike i~ lakes -.Oahe 'tf~d · - . · ··:] J - - ~ · ·

1._''· .. · _,. Sharpe, South Dakota. : Tran~. - ~~-- ~ish. · ·soc. 99: .36~-37~. : · ~ , _ : . ~ - .L .

r ~ ' ' . Ha-tfield~ ·c.-r:: J.N. Stein, M.R.' ' Fal·k~ arid c·.s:_., JeSsQp. '' 1972 • . Fish , · . ·i' :- ! . _ resourees· of ·the Mackenzie River valley . -~.Envirohl)ient Canada,' · : ;,· . ·:" ~ ~ · _ f _ _ _' · .- Fi~her_i·es Servi~e;. In~~rim R~p. 1 ; - 1, __ 247 p: _ _ ·· ' · ' : · ., ~ - :-l ,M

·· • t ' ·· Hederstrom~ .~ :· ·1759!. ·Ron om Fisk~rs ~Alder • . - Ha.ndl ~ -· Kungl .' _ . ' · .. ._ · · 1 :··.Vetens.kapsakademfn iStockh_olm) ·_?0: ·22~-2-~_9 ... (Re-publ ished in . Rep ~- l!lst . f-reshwa~. · Rrs,,: orpttryin,gho1m. · 4~: 1_ 6i-164(185~:}_ -.t ,as Obse_rvat1ons on the age, of f1~ hes ) ; _ 1 · · - · : · ·; · . _ . . • -- :~ •

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.'-.H~ffba,uer, C~ -. 19~~- -' ~eit~~,B i~rage· · ;u~.~l~e·rs~~~~·-·_ . ·.. , . · .. ~: ~· . · - ~.:.::~_;_~.':'--~-··· . 'f. · - ~lachstuli1Sbesti-ITIIltl_nJ. -~er- Fis he., spez_~ -._. des ~: ~rprens:...· ._··. - ~"

y . ·· ··s..~ ~- ··_.". - ~~itschr~ Fisch.· 1~: ·111-1 2·~. '. ~,-,; .· ·_ --:- · .. · .. ,. .. ? \, · ·• · ' ~-: •. _; · . Q . _ • , • • ~· - . ", _:; ~~t

Jensen, A.C .. . and K.-B. _ Cunmi.ng. ·1 6i~· tls~ · oi,· Jead .. compoliQds ·and ··': ' ' .. _ .-.:;;~'."· . · ·tetracycline to -mark scales nd oto'liths pf marfne' fishes. _ · · _: . _ · . . :· --- -:~f~~--

. ... Prog,. F~_sh cult: "29: ,166-167. · ' · · · --· • · · ·_ ,,. · __ , ~· - •··. :-···:::cy 'll~hnsqn, - LD. - -: 195~.- · Stor-y .of.,a th usand ·stomacH~. · Wi's. · conse~v~ : · · - ~ - , -~ ·. ), · Bull.. 2~: 7-9·_. · · . , · . ,._ • · ~ ;__,_ · ot! '

<C 1 ' ·~~.1, ' • " ' ' • ~ ~ •' o ,....,--' ,- v: " .f '• I ' .,·I '

·Johnson, L 19.76. _Ecology of arcti , pqpu1ations· of fake trou:t·,: . · 1 • • • ' · .:}_:

r' Salvelihus nalnaycush,., __ lake white .ish,., Coregonus' c-lupeafonnis; . • ;-- _: · :.-"J .· -. ·- ·arctic 'char, .?.~ a1pinus ~nd · asso i~ted spectes/n unexploited · ~ - .. ~ ·::1'·

lake~· of :.the Canadian Northw~st T rri fories <:.- "'· : F:ish>Res. . J .· • . ._ ,~ • .' Board Can. . 33: 2459 ... 2488. · : · · · - · ·. -. ; . ··· .r;i · ·

•, ·'.. - . ~ .:· / , -\ I ' . '~ ~· . • ;i) .

Kandl el't' R. ·and ~1. ·_ Ptnji tz. 1957.; .. Uber d-ie ftii~~!~t*~~l~/~~,r- ·_ .· J . p 1 attfi s_che i.m Nordsee·Os tsee-R~wn •. __ Kie 1 ef.;~~:f~1*¢h~ ~ - . ~~ <~L .13: . 1.:1'-34. · <>. ,. . • . . • • ''\, ••• • •• •. · •• -• • :; '

• . -~4

_ ~ipling, - c.- '1975 • . Ttie , effects·~f variati.o in-4 growth onth~ - .. _- .-· _- · <~ , :\· _ g19n7._15net2"3se(lsect11·~n1 ,ovf· a

1· po1 p)_u1 _~8t0ion89. of _pl e~ _ fJF~C .Tech:Pa_per _ . .. l _ ~_- -:~:{--.~.-.i_t:·.·.~ •. - .

• · ·'_,.:t , ' · upp . : .. o . . . . - .• . . ... .·... . .. . - · . ... _

-~ . U!Cren, E.~.- .1947; . - ~he d~t~~in~~io~ -~; : ~the \age ·and./ g~owth ·~t the ' • . ;:..· ·.. - .-~f!: - -· p~rch (Perea ·fluvia'tilis). from the _opercular bon_e. J; ,A~im . . · · .· . .-_:_·_:,

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· : · E~ol. .16: l88-2ot . / _ ·· · ,?

• I) • , . • • • • : •• : • , . • ·.1 ' : '.. k •• • - ~- • : ~'"_ · '~·

. MacKay• .t_ T • .. 19Q?. ·~ An ec~logic~l ·s_tudy :of.-ma.ckerel, -Scomber _ ' :-) .. ' o . : stomb rus, in . the coas :ta 1 wa te.fs of: 'Cariada ~-- :.: ·Fish: Res. Board · . · . ~'J

· · -.. ·can. Tecp." Re·p. No·~- 31. :· .- . .'.- _ . . . _ . .,=·-· . ··· ' .. _, .. · .(;~ _-. • : • . . • • " • • .. . ... ~ . ',_ ' ' • • ' . • , . ,.- .... • . •• . " • ~l~· :

· t-lann i.).H.i<. ·· 1976. 'Obser:vations ~n . the· a,ge, growth, _reproducti'Qn ! _: · , ·. ·· 1 I

. an~ .foo~ of the. pike _ ~sox- 1u~ius =·(L~ )._.jn/ tWo ·riyer-s ·in ~ · -~~ ·' · .' /1. -' so,uthe"!_.Engla,nd1 J .. -~ ·Bl~l. . . B.;.=--::179-197. · . · >:r---

Na~a1dri, D.C. --and H· .R;}I,actri~~, . 1_979 .. :· Compari.so'n · of.ageing . . .0

t- ·. r · , · ·methods ·and, 9!'0\'lfh rates fdr "'~ argemo uthb~ss, MiC r6pterus · . · · .. - · , i · · " · -. .. salmoides L.acepede·,.fro·m northern latHudes • . Env. Biol.. __ ; •. · , , , -·- :; . _

• . ..; ·Fi~fi. · . . 4: -2~3~27] .. . ' . ~ . . •' . . • . .· •I ·' : •. ->.. .. . -: ·-· .I ._, ,:T ...

· .. )~e~f~~. B •. ~. ahd W.C. 1

Mack'ay. ·_il-978: .' Prbteiri. ~t:Jd lfp'id .co(lte.n:t _ ·: ,~~ ., , .·-_ o .. _.' . '_:~_-.: __ -~.::.f.~ _/_· -'~-: . · .- · ... • of gop_ads r ·,] ve.r, an~t mus.cl e·. of northern pike .(Esm(·;l uci us"). · ~

. :; · - in rel'ation ·. o_' g~nad "' grow~h ~ .J; Fish ~ ; Res; _ Board C@_n, =35: .~ ·. ·._ . . . , -..-:-;·: . . - 2l3-2J9:. .. . ,, : . ·. ·:. . . . . · ·: . . .. . . . ; ' ._, ._, __ -~-.

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· Miller~. R.B. ~ .'-~nd H.A.· .Ke'nned.l • .. J94~:' ~ Pike {Esox· :lucius) from four . · e- · . ·northern· Canadian .lakes : J~ .Fish • . Res~ Board·can. '7: 190-199.

. . ·. . . .. . : . , . . . :. . I - . : . . . . .

-Monastyrsky, ·G.N. 1930.' Methods of. determi.n_ing :the growth )'in .length . ·. ' of: fish by .th'e~r · s_cales [in Russ·iari]. · Trl!dy .nauch. ry~~ Khozy~ · -: ·, · . ' 5: . 4. . . . .. . . .. ~ . . . . ·. . ' .

. . . ' . .

- , . · Pars-ons, ·R.F. · ~9_75.. ;:rhe li·m~ology: _ and fish biology .qf Ten Mi.le ·, Lake, · Labrador~ · Fish. ··Mar • . Setv; Tech.,, Rep. Ser. No~ NEW/ .

. . J:-75-3: 75 .-P.· · - . . ·.. '-" . ' . . . .

jow~ll. ~heppard T. · . -power project •

. Vol. -1)\.

Associ.ates (c.anad,a) Ltd •. 1971. . Chu~chill .Falls _Wate_r _ qua'bit.Y and biologi9-l study 1970-71.' . •

r ' , • / I

Q ' : ,. .. •• "

Power, G •. 19.,78. Fish -populatlon . st~ucture in arctiC lakes~ .J. 'Fish. · Res. Board Can. -·35: . 53.;. 59~ ·. · · · · , . ,_ - . ·. ' ., .- I .

Priegel, G .. R. a,nd D.C. ·Krohn. : ·1975. Charact~ri·stics ·of .a· northern · ~ · pike s·pawning p_opuJation. - l~isc. Oep't. Nat. Resources·· Tech.· ·

Bull. No. :86 •. · -: • · · -: - :-, . . . ' ... - f . ' • - ' • ' ' • \ • • • • '

'Ricker, W.E. ·_ ·19.75. Computation and interpretation ·of ·b.jological statistics· of fish. populations. · ' Bull. Fish· . . Res • ...._Board . Can.

. Np • 191_. . . . . , . : . • ... .. . . . . :' I . ' . . !' ..

·Schott. J.W. · .1965. · A'yisual ai'd for age determination of -immersed ·. . \ . • .. otoliths. Cal if. Fish Game Sl: 56 ; .. -. • ·

-~ -

·,

., ._

. '

' • ' I' ~.. ""' • ' ~ ..... : • ' ' ,•, ' Simpson •. A. C. 1951. "The-decundity of the-plaice. U.K. Min. A_gr.

. · Fish •• _ Fish. I~ vest.; Ser. · 2: _· 17(5): 27 p. · ·. /

. svardson. ,G. 1947 • . G,addlekst~dier. ' S~dr~ - Sveri-ges· Fiskeriro~. · . .-Skri.fter, ',1946: - 34-59._ , · ·

. . . . : ~·. . .· svetav.idav, ;A.N. · .. ~929. To the ·questipn of age and · growth of perch,

rudd arid· pike from · the 'Lake uKri.tgloe [in Russ_iah, . Engljsh ~ 'sm~ry]. Rus_sk ._ i!ool. lh ~ . 9:· 3~?2.

. Tes~h.; F. W • .. l.96B • . Age an.d ·growth . . p .• 93~123. · . -~ W.E.· .Ricker. . . ·, {ed.). /Methods ·for assessment of fi sh1 production ·in fresh . : . . -

. \'la~rs. )BP Handbopk No • .. ~, .- .Blackwell .Scientific Publications. · Oxford ·. and Edinburgh. . · ·· ' · · · · · ·

' . ' . ~. . '

.- ,· r Tn:,ut. G. c. ·, 1956 . .. The·· ot~'1 _ith _ : Doc .• · No . .. ~3 ~-38. _ _

. . arid age determination. · ICNAF ·

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1-Jilliarni; ·J.t. · .·1955~ -: :oetermjn·ation yf_ age ·frollJ the s_ea.Tes . c:lf · ··.·northern_pikt!·. (E:sox 'luc-ius· L.), Ph.-0.' -The-sis. University

·of Mit;higal')~ .AI)n _Arbor, -Michigari. las p ~ ·' .. . · , . ·. · · : ,' . .. · .. ·, . .· . ,... . . .

'Wol.fe.rt, ': o.R~ · and. ·r.·J. Miller . .. 1978.. Age,. .. growth • . and fQod · · of northern pike in eastern Lake Ontario. · Trans.···Am. Fish. · "soc.-· 107: 696-702; .:· . · · ·- · -·

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. . lar, J.H;: .1974. Biostat'is~i.cal analysis :' · Prentic~~·Hall .·I~c., .

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