la) Serial No. N1772 NAFO SCR Doc. 90/51 (Revised) SCIENTIFIC COUNCIL MEETING - JUNE 1990 An Assessment of the Greenland Halibut Stock Component

Size: px

Start display at page:

Download "la) Serial No. N1772 NAFO SCR Doc. 90/51 (Revised) SCIENTIFIC COUNCIL MEETING - JUNE 1990 An Assessment of the Greenland Halibut Stock Component"

Ilene Williamson
5 years ago
Views:

1 T T BE CITED WITHUT PRIR REFERECE T THE AUTHR(S) orthwest Atlntic l) Fisheries rgniztion Seril o AF SCR Doc. 9/51 (Revised) SCIETIFIC CUCIL MEETIG - JUE 199 An Assessment of the Greenlnd Hlibut Stock Component in AF Subre 2 nd Divisions 3K nd 3L by W. R. Bowering, W. R. Brodie, nd J. W. Bird Dept. of Fisheries nd cens, Science Brnch, P.. Box 5667 St. John's, ewfoundlnd, Cnd A1C 5X1 Introduction Greenlnd hlibut ctches in Subre 2 nd Divisions 3KL re hve verged between 25,-3, t nnully from 197 to 1976 with the 1978 ctch being the highest since the beginning of the fishery in the erly 196s t 39,5 t (Tble 1, Fig. 1). Ctches declined rther stedily since 1978 to rech n ll time low of bout 16, t in 1986 (Tble 1). In 1987, the fishery improved to the extent tht the 1987 ctch of 3,9 t (Tble 1) ws nerly double the 1986 ctch nd bove the verge over the lst 18 yers. The 1988 (Tble 1) nd 1989 ctches (Tble 2), however, were gin ner the lowest in the time series t 18,9 t nd 19,5 t respectively. Most of the 1989 ctch ws ccounted for by Cnd with 11,9 t; followed by EEC with 3,2 t; the GDR with 1,7 t; nd Proes Islnds, USSR, Jpn nd Polnd ccounting for most of the reminder. The Cndin trwler ctches were 9 t in 1989 compred to 6 t in 1988, nd ws tken minly in Div. 3K during April, My nd August (Tble 2). The inshore gillnet ctches were minly in the southern divisions of 3K (5,8 t) nd 3L (2,5 t) with 2,2 t tken in Div. 2J. The gillnet fishery occurs primrily during the months between July nd ctober. Ctches by other countries vried throughout the yer, quite often in conjunction with ctching other species. However, while Div. 3L hd been rrely directly fished for Greenlnd hlibut by countries other thn the costl stte, ctches of 4,1 nd 3,2 t were reported by the EEC in 1988 nd 1989 respectively. Ctches in 199 re expected to be much higher. The TAC hs incresed from 3, t in 1976 to 35, t in 198; 55, t in 1981, for Div. 2J3KL only, with n dditionl 2, t in Div. 2GH; nd to 1, t in 1986 where it hs remined through These increses were ttributble to indictions of good recruitment, estimted high levels of biomss, nd wht ws considered to be low overll levels of fishing mortlity prticulrly on older fish in deep wter. The 1989 ssessment indicted tht the stock size hd decresed substntilly in recent yers to level of bout hlf tht when TAC of 1, t ws introduced. Therefore TAC of 5, t ws recommended for 199. However, the resons for such lrge decline in stock size re lrgely unknown. It is worth re-emphsizing tht this resource undertkes extensive migrtions throughout its life history, with the min spwning component migrting to Dvis Strit while the younger immture portion of the stock (prticulrly, ges 6-1 yers old) supports most of the fishery in the southern res. It hs been cutioned by the Scientific Council tht ctching the TAC would not hrm the resource, provided it were spred over ll commercil ge groups nd ll res of the distribution. If, on the other hnd, highly-concentrted effort were directed in loclized res on few ge groups, significnt component of the stock could be detrimentlly ffected. Reserch vessel surveys i) Biomss estimtes nd bundnce indices in Divisions 2J3KL nd 2GH Results of strtified-rndom groundfish fll surveys for Greenlnd hlibut in Div. 2J ( ), Div. 3K ( ), nd Div. 3L ( ) re presented s men weight (kg) per set per strtum in Tbles 3, 4, nd 5 respectively. Biomss ws estimted for most missing strt using multiplictive nlysis model. For the re estimted in Div. 2J in 1989 (Tble 3), the biomss estimte ws 42,774 t, which ws the second lowest in the time series. The previous low ws in 1988 t 35,45 t. The verge biomss estimte over the time series is 69, t. In Div. 3K, the 1989 biomss estimte ws 72,631 t

2 (Tble 4) which is ner the lowest in the time series nd very similr to estimtes of 1987 nd The verge biomss over the time period for this division is 85, t. In Div. 3L, the 1989 biomss estimte ws 13,319 t (Tble 5) nd is virtully the sme s the 1986, 1987 nd 1988 estimtes. These estimtes re within 2% of the verge biomss for Div. 3L of 16, t since For Divisions 2J, 3K nd 3L combined, the estimted biomss for 1989 ws 128,724 t compred to 121,597 t in Trends in biomss by division s well s the three divisions combined re presented in Figure 2. For Div. 2J there hs been rther systemtic decline in biomss from bout 18, t in 1982 to n verge of bout 39, t in , decrese of nerly 3 times. In Div. 3K, on the other hnd, with the exception of high point estimtes in 1983, 1984 nd 1986 the estimted biomss hs been reltively stble t bout 75,-8, t since The biomss in Div. 3L ccounts for much smller portion of the stock lthough very little deep wter is surveyed. Biomss estimtes from this division hve been remrkbly stble since fll surveys begn in 1981 t level of bout 13, t. The overll combined trend, however, shows considerble decline in biomss since 1984 (Figure 2) lrgely becuse of the significnce of historic levels in Div. 2J. Although stble during recent levels re bout hlf of erlier estimtes. ii) Ctch numbers t ge from groundfish surveys Strtified men numbers per set (from fll surveys) t ge re shown in Tble 6 for Div. 2J nd 3K from 1978 to 1989, nd Tble 7 for Div. 3L from 1981 to Reltive yer clss strengths t ge 5 (ge t entry to the commercil fishery) from these surveys re shown in Figure 3 by Division nd in Figure 4 for Div. 2J3KL combined. It is pprent from the dt presented tht Greenlnd hlibut do not fully recruit to the survey ger until ge 5 s evidenced by the 1979 yer-clss (Tbles 6 nd 7) which hs been predicted to be strong yer-clss, prediction which hs been borne out in fisheries to be true. The 198 yer-clss ws lso predicted to be strong yer-clss from dt exmined from shrimp surveys. Although it ws more difficult to rech similr conclusion here. The dominnt ge-clss in the 1987 survey is ge 3 which represents the 1984 yer-clss nd is more bundnt thn ny other yer-clsses t ge 3 in the Div. 2J3KL series (Tbles 6 nd 7). Up to 1988, this yer-clss ws lso more bundnt thn ny other yer-clss t ge 4 thn ny other in the series (Tbles 6 nd 7) nd gin t ge 5 in the 1989 survey (Tbles 6 nd 7, Fig. 3 nd 4). The 1989 survey indictes tht the 1985 yer-clss my lso be quite strong. In the previous ssessment n exmintion of dt from shrimp surveys showed tht the 1985 yer-clss dominted the ctches t ges 1, 2 nd 3 lso suggesting prticulrly strong yer-clss. Unfortuntely, similr dt from shrimp surveys re unvilble from A comprison of reltive yer-clss strengths t ge 5 in Div. 2J,3K nd 3L presented in Figures 2 nd 3 scled to the 1984 yer-clss suggests tht the 1976, 1977, 1981, nd 1982 yer-clsses re verge, with the 1978 nd 198 yer-clsses possibly verge to just bove verge. The 1983 yer-clss is estimted to be reltively strong from Divisions 3K nd 3L dt, however, is wek ccording to Division 2J dt. The 1984 yer-clss, on the other hnd, is estimted to be strong throughout the re nd is similr in strength to tht of the 1979 yer-clss. Commercil dt i) Ctch nd effort Considering the nture of this fishery nd the migrtory behviour of this species s well s the low levels of directed ctch, it is difficult to obtin ctch nd effort sttistics which re ccurtely representtive of totl stock bundnce. Those tht re vilble (minly, Cnd ()), however, cn be helpful s indictors of distribution nd bundnce in loclized res. The only directed ctch-effort dt vilble during the lst couple of yers ws from Div. 2J in the summer (Tble 8). It ppers tht the ctch rte declined in Div. 2J from 1984 to 1986, incresed in 1987 to level higher thn 1982 but still below the levels. It subsequently declined in 1988 to the lowest observed during the period exmined. There ws virtully no directed ctch of Greenlnd hlibut from this fleet in 1989 lrgely becuse commercil concentrtions could not be found. ii) Ctch numbers nd weights t ge Ctch numbers nd weights t ge were clculted in the usul mnner for the 1989 Cndin fishery only. The dt for foreign fisheries were unvilble t the time of the meeting. The results re shown in Tble 9. About 53% of the Cndin ctch ws comprised of fish t ge 7 with 94% of the ctch being comprised of ges 6-8. Hrdly ny were cught beyond 12 yers old. Mtrices of ctch numbers t ge, percent t ge, verge weights t ge, nd ctch biomss t ge up to 1988 re shown in Tbles 1-13 respectively for ll countries.

3 3- iii) Assessment Sequentil Popultion Anlysis (ADAPT) n the recommendtion ttempted, using the ctch index of bundnce for Div Div. 2J3KL combined (Tble clcultion of n index of Adptive frmework used is of STACFIS t the 1989 meeting, sequentil popultion nlysis ws t ge in Tble.1 (from 1978 to 1988 only) nd the r.v. survey. 2J (Tble 14), Div. 3K (Tble 15), Div. 3L (Tble 16) nd 17). As noted previously, there re insufficient dt to llow bundnce from CPUE for this stock. The formultion of the given in Appendix 1. The estimtes of bundnce from the model were significnt t ges 6-12 (Tble 18). The estimtes of ctchbility (RV slopes in Tble 18) show n increse from ge 5 to 8, reltive stbility t ges 8 to 1, then slight increse to ges 11 nd 12. However, it should be emphsized tht these vlues re extremely high (over 2. for most ges) nd considered to be unrelistic for this species, for which previous vlues of ctchbility hve been estimted to be s low s.2. The model lso shows ptterns in the residul mtrix, which cn be seen in Tble 14 nd by the lck of fit in mny of the ge by ge pots in Fig. 5. The correltion mtrix (Tble 19) shows, in generl, n cceptbly low level of correltion between most prmeters. Results of the sequentil popultion nlysis in popultion numbers nd fishing mortlity re shown in Tble 2. Given the estimtes of stock size obtined from R.V. surveys long with the recent ctch levels from this stock, it is obvious tht the estimtes in Tble 16 re not relistic. Although the SPA my be useful in indicting decline in stock size from the lte 197's to the present, it is known tht both immigrtion nd emigrtion, by ge nd by yer, occurs in this stock nd re likely to be highly vrible by ge nnully. Such movements would ffect both the estimtes from surveys nd the ge composition of the commercil ctch nd my explin the vrible nd high vlues of F t some ges in certin yers. The present nlysis ppers to serve little more thn emphsize the significnce of these fctors. Thus, little fith cn be plced in the SPA s true mesure of stock composition nd size until these migrtion fctors cn be quntified. Tble 1. Greenlnd hlibut lndings (metric tons) by yer nd country for Subre 2 nd Division 3KL from 1963 to Country Cnd FRG Polnd Icelnd orwy USSR Romni GDR Den-F Rin Den-G 65 2 Portugl Fr-M 5 Fr-Sp Jpn r t he Totl Country Cn d FRG Polnd Icelnd orwy USSR i ; 15 li i Romni 3 GDR Den-F R in i. _ 3 Den-G - Portugl Fr-M Fr-SP - - Jpn ther 9 - EEC 4118 Totl Provisionl. Yer Yer

4 4 Tble 2. Greenlnd hlibut preliminry nominl ctches during 1989 by month from AT Subre 2 nd Divisions 3KL. Jn Feb Mr Apr My June July Aug Sep ct ov Dec Totl 2H 2J 3K 3L Cn (SF) (In) (off) Cn () (Ins) (ff) Cn 2) Cn (G) Jpn 477 GDR Polnd EEC 3195 Froes 73 USSR ton; cught Aug ct 2H Cn () (ff) (Ins) J Cn () (ff) (Ins) , 221 3K Cn () (ff) (Ins) , 3L Cn () (ff) (Ins)

5 _ 5,.m. wzr.m..pgrgp22 gg2 mmg=i...mw P.22,A22,P242P24 M. 228 nns 14. M P: :r:rfr;r4.;444:.4.4.4,4o;4 "HI "" m R 1, 4 i W1=1;:1 4"1==!=i ER.""1 2 r.4 MC1' M.. M.M :4:PP PPg 2 2 dir:ar4' 4.4e; P P "(4A M, V.W... M....M.. M.. M V vsss:::17:sr;:nrsnr sns TIA8PP 28A 2. e2 r,iri.444,a4w er4 :e. 4 4 MM.1. e M... M..V.. M. M.M. MM. A 2PA2m2A:".:2P - gr22 :P2.222, P88 ". 4r44;e4:4;r: 9:.4,1/2gilli lir 4 : even, lim V M. V.V.. M r)18 2.' F '2:::... 22P2"442. M... 5.EF..F4-.. MM. q j) }})\\{ } 2288; :122P em ' i, m. 2...MMMM... MM.... ri,gp.. g g" g2 I I r "2:g W4V el...m.v.. V. 282 P , P7i 1 "2";: P g M 2:424A24. ;7,7 1 ' : 2P,1 4IWfl 4: :q. 2, 2zg mitn7:273r, gr- PdrIt2e1 g2. r, -mmegg 4 2 ts F. 74' sal Ag SW, F.REUME F.ii m ;1;1

6 ,_i o4 pi r C C el el en 1. M PVD M en re re in in.4 m I en 1 in re %CI P I-- In Co 1 1 re 1 H en In el M Ch in cn rn Co LA en l YI m P n o C C. el o C ev re o en el I b e M el re 1 I I I I m. 1eri1.1 Co r M Co 1/4 C is3. I H 1., Co in to 8.4 it H H el H b -I.-- re - H H in in en V WI in in en 1 3 in 4) C C WI n in It ineir-r1inenreerinercrelln I-- MI r- en in H H en in el IA Co re er Lel 1 1 Co r- It. enelinulin Wommrnin ito I I I el I I I I M M 1 er in r. H H.4 H..4 H - - in ^ ^ H r r Co..4 H M in in in ID in en en H.4 It H le- en In co V r L V) L M in UP r o In H In Co Co C in. en. el H Co Co 1. en Co ICI in L t 1".. in 1 re le. en in ce. r b ul T t. 1 Cn el (ner- I I o M in en P Ul H H et I re en en - in Co -. en C in in ) H 1C.1.1P. 111 It Yr V V is3 in co el C Co in Co in In in en in It r- ie) ri le in ni t 1- V Cn.1, In I H H H In en 1 en CA In in r re eh M HM in 1".. I I I I I I I H V) Min 1/4 to Ill 1 4 H H re el ul re..4 r Lel ID re HelerierIllinr- ereren.411"..1"...43rner Ill rn en en Mr-3M31-.1CCi.4er M in it In in en 143 en H C in P 1. en in in It in I in Co in re 3 r- c e4mc erererelerccim I I eln. I I H in 43 1l1 er 3 H el el re m M -- ^ H eh Ul.-1 el er U1 In I-- er en in H c W H eft fn b C4 It m re Ul in in el rn MI in en r- in ef ell ill in c el in 1 1 ni re e r. U1 I...1. en U1 er ul en in.4 H 4 6 y H.1.4 H 1 C C l re o r....1 I-- In I re Ul. P re re n1 el I I V I I I H el r- ei - c) en rel H H of r4 1/4 C inc.4 M H H I m.--, H el fel er en U3 in re in en.4 in 1/4 in..4 re rel 1 en - - re in. Pi in m to r- M in co MIn Ul el lei in in..,, 2.4 en en r... co re en 3. re en re H r b o to 1n n io m rip to noot,11 el I I I re el I I.-1 H re en el M is3 1 1p H H el el A S m -- ^ en. In ^.4 rn in ul r 43 el M r ei in H r H H en P w ri r 1 en C In in in I CZ) rl. Ul1 WI 1 M e 1 in o in to r rel in in en I in in I er. re. I T V' I I en In retie' 1/4 M - el on en.4.4 H H H It er in en re in Co re In L it C L in It...,... _ 1 en en in In en M U in in H C en in in o. n ieleninen.fnenleren noon ni 3 r.. -. re in oi m in H In l.-1. in. el I-- el 1 I el en re I I 4 en 1 C C 111 C H 1 H HI.4 n1 4 en , - m o Hm to v 1/4 in It WI in en.-1 u3 le. CI It It It H In M H 1 C 1 HCCIltfl WI.. en H IHelL IHITI CM in 1 1 I I io co in in o iir o co co o -I 1/4/7 in t H.4 en el en I I ri.-1, I I er C el. n to 1/41) I re f n.4 el el el in M en.-. in co 4 el 1 I Co.4 ei rl in in in in r n Ch re cn re rn in ri le. CT cr1 er en com 3 coompooninion n iwoi P.m. M rl en tri VC el I-- eel re en..4 H el 1/4 in. ID en in meremomomomicoo tor 1. 1 o i coo I I CY HI el CI H.4 T fel H H 4 H co H H t Ill S.4 It ei..4 re ii3 r. r- re re en s Cn e-. l co o I CY p cm CY en M C el.-i te.. en ei 1 rel in el el in rn 1 el V re in ei H - r er et in M Ul r el re er el et in to 111 cn...i.-4 1 re en oi It to %.o m 1 en H en le. in en Co in V,. in in in co in i in o re in H r- no re m H Ill el el - pp kb ) Cri el H 4-3.,.. 41 l C.! V/ VI 9.4 It.C. g en 1.13 r- < 1.4 in in I-- cot el re es in,...1 ey r 3 en ry co el ro > C M co C c. CP or. or or 1 o4 cg of ii,,,i, L to 43 ID W co `43. VD 1. Lo ni 14 '. 4:3 1, t. 4{I IQ to 'Id t 1.., t1 -,7 44 S4 4J H k g el e4 e4 -.1 U 4.1 %M el K

7 - 7 - Tble 5. umbers Averge weight (kg) of Greenlnd.hlibut per set from fll reserch vessel surveys in Division 3L. in prentheses indicte number of sets per strtum. Strtum ATC 323, 324, ATC 333, W.T. 7, 8, W.T. 16, 17, W.T. 37, 38, A W.T W.T W.T (4).9(8).52(6).25(4).6(7).1(7) 341.5(3).19(4).8(4).5(5).26(7).4(7).62(9).31(8).26(8) (3) 2.83(3).87(4).(2).73(3).2(3).(3).23(3).17(3) (4) -.53(3).(4).8(3).2(3).(3).(3). 27 (3) (4) 1.(3) 4.34(6).18(6) 2.46(9) 4.63(7) 2.88(4) 3.2(7) 6.89(7) (4) 8.67(6) 9.25(8) 39.6(7) 36.61(9) 6.26(4) 18.(2) 23.7(7) 12.43(7) (3) 11.63(4) 17.5(5) 27.33(6) 35.8(5) 26.6(3) 22.5(4) 16.(5) 25.75(4) (3) 3.2(4) 2.58(6).17(6).76(4) 2.94(4).13(2) 2.3(5) 15.1(5) (6) 2.8(5).3(11).11(11).61(14).88(5).43(9).44(1).29(9) 349.9(7).3(5).43(9).1(14).7(1).9(9).24(1).(9).4(1) 35.(6).(2).(8).(12).(9).(11).(9).(1).(1) 363.(4).(3).(3).(8).(1).(7).(9).(1).(9) (9).25(11).87(11).(1).5(18).14(5).53(14).27(14).35(11) (4) 2.75(4) 1.3(5).3(4).12(8) 1.8(5) 3.18(6).3(5).9(5) (3) 9.58(6) 6.(4) 6.23(11) 18.9(9) 1.9(4) 8.11(7) 2.64(7) 11.5(7) (2) 28.75(2) 17.75(2) 29.(2) 6.66(2) 9.(2) 21.75(2) 27.25(2) (2) 13.(4) 14.(6) 5.19(7) 13.33(6) 6.36(3) 9.25(4) 3.64(5) 4.8(5) 37.(4).5(6).44(6).39(7) 1.52(9) 2.3(2).25(6).1(7).4(6) 371.1(4).(5).(5).(7).(7).4(3).(5).(6).(4) 372.(5).(7).(4).(13).(17).1(9).(13).(13).(12) 384.(4).(3).(6).(8).8(5).(6).(6).(5) (8) 2.19(8) 3.2(5).5(12) 1.24(12) 4.67(8) 2.44(9).(13).17(11) (3) 21.75(4) 12.69(8) ) 8.34(4) 6.13(4) 4.86(5) 1.9(5) (2) 43.67(3) 49.( (4) 8.(2) 26.33(3) 12.75(4) 15.33(3) (3) 24.(2) 24.75(2) (2) 19.(2) 15.5(2) (4) (6) 26.8(5) 9.8(4) 11.25(4) 8.88(4) 1.25(2) 39.(3) 3.5(4).7(3).(3) 2.72(7) 3.62(6) 1.6(8).(8).57(7) (2) 21.5(2) 18.75(2) 29.75(7) 8.25(2) 4.1(2) 2.4(2) 13.(2) (2) 15.25(2) 26.5(2) 25.(2) 18.(2) 8.25(2) 13.25(2) 12.(2) (2) 3.5(2) 17.92(2) (2) 6.75(2) (2) 15.(2) (2) 21.(2) (4) 35.83(3) (3) 37.(2) (2) - 42.(3) 29.25(2) 47.5(2) (2) - 7.(2) 52.53(2) Estimted biomss (t) (surveyed re) 12,722 11,649 6,634 17,548 23,848 1,61 9,821 1,851 1,518 Estimted biomss (t) multiplictive model (ll strt included) 17,336 14,439 14,255 18,8 24,66 13,543 13,28 13,496 13,319

8 - 8-- Tble 6. Age composition - numbers/stndrd tow from groundfish surveys in Div. 2J, 3K (ll strt fished). Div. Age K , unknown Totl J unknown Totl

9 Tble 7. Age composition of Greenlnd hlibut - numbers/stndrd tow for Division 3L. ATC 323, ATC VT 7, WT 16, VT 37, A.. WT VT WT 324, , 334 8, 9 17, 18 38, Age Unknown Totl Tble 8. Ctch nd effort sttistics of Greenlnd hlibut in AF Div. 28,73K from Cnd() where effort ws considered directed in AF Directed Yer Div. Months Men CPUE (t/hr.) ctch (t) Cnd() (TC 5) 198 3K Mr-My K Mr-My K My J Aug-Sep H Aug-Sep K My-Jul J Aug H Aug-Sep K My-Sep J Jul-Sep H Jul-Sep K My-Sep J Jul-ct H Aug-Sep J Jun-ct J Aug J Aug-Sep

10 - 1 - TABLE 9. CATCH AD AVERAGE WEIGHTS AT AGE FR GREELAD HALIBUT BY CAADA DURIG 1989 I SUBAREA 2 AD DIV AVERAGE CATCH AGE WEIGHT LEGTH MEA STD. FRP. C. V ' ,2 Tble 1. 6,11AL CATCH AT AGE MAIL AGE I J : I : B : ' Ig : II I 1 43 I I IS : Tble 11. GAL. PERCET CATCH AT AGE. AGE ; : : : I.B : B I Tble HAL. MA WEIGHTS AT AGE (KA). AGE ' i I : II : : : I

11 Tble 13. G.HAL. CATCH AT AGE W. AGE I 1% % Tble ABUDACE AT AGE FRM CAADIA SURVEYS I M. AGE B ' II ' ' , I

12 Tble 15 G.AL, ABUDACE AT AGE FRM CAADIA SURVEYS I DIV.3K. AGE BB I : I I II : ' Tble 16 G.AL. ABUDACE AGE FRM CAADIA SURVEYS ( DIV.3L. AGE I D I I I I

13 Tble 176.8AL. ABUDACE (11-31 AT AGE FRM CAADIA SURVEYS I DIV CMB. AGE: : I : I I : I I : : ' , * ' I I TABLE S. PARAMETER ESTIMATES AD LG RESIDUALS FRM A ADAPT AALYSIS USIG RV DATA FR GREELAD HALIBUT I SA2 4DIV. 31_ ESTIMATED PARAMETERS AD STADARD ERRRS APPRXIMATE STATISTICS ASSUMIG LIEARITY EAR SLUTI RTHGALITY FFSET.378 MEA SQUARE RESIDUA'S AGE PARAMETER ESTIMATE STD. ERR. I-STAlISTIC C.V ABUDACE E E E.58 6 ABUDACE E E E.38 7 ABUDACE E E E,24, 8 ABUDACE E E E,18 9 ABUDACE E E E.27 1 ABUDACE E E E,27 11 ABUDACE E E,28 12 ABUDACE E E E.28 5 RV SLPE E ' E,18 6 RV SLPE E E ' E.17 7 RV SLPE E E E.17 8 RV SLPE E 5.496E RV SLPE E E E.18 1 RV SLPE E 4,96446E E RV SLPE E E'" E RV SLPE E E 1 5,58864E.18 LG RESIDUALS FR RV SURVEY IDEX 3/ 6/ ' ' U ' ' _ ,41, ' '.45.56,79.22 SUM F RV 1 RESIDUALS :.4792 MEA RESIDUAL.54

14 TABLE ig. CRRELATIS HETWEE ESTIMATED PARAMETERS FR GREELAD HALIBUT I SA2 f DIV. 31(1, FRM A ADAPT AALYSIS PARAMETER CRRELATI MATRIX 3/ 6/ I I I. 1 I I ' I ".64 5 I I, ' I.6.8, , I.4.6,1.11, " ' C " , I ' ' " ' ' " " M " H ' ", C I " ' , ,

15 V). TABLE 16., PPULATI UMBERS AD FISHIG MRTALITY DERIVED FRM A ADAPT c. AALYSIS USIG RV DATA FR. GREELAD HALIBUT I 5A2 + DIV. 31(.1. PPULATI UMBERS (5) 3/ 6/ I I I I I FISHIG MRTALITY 3/ 6/ S

16 Hlibut Commercil Ctch (t) in SA21-3KL BB 89 Yer Fig.1 Commercil ctch of. hlibut in 5,42. Div. 3KL from i Division 3L 17) M I I I ' I Yer Yer I ^ Yer Yer Fig.2 Biomss estimtes of G.hlibut in Div. 2K,3K & 3L using multiplictive model to fill in missing strt.

17 I Division 2J Age Yer-Clss 3. I Division 3K Age , Yer-Clss Division 3L Age Yer-Clss Fig. 3 Reltive yer-strengths of ge 5 G. hlibut from Groundfish surveys in Div. 2J,3K & 3L.

18 G. Hlibut Yer-Clss Strength p Yer-Clss Fig.4Reltive yer-clss strength of G. hlibut in Div. 2J,3K & 3L combined. Stndrdized to the 1984 yer-clss.

19 C c. CD +, +, + CV -1 C.1 L SPA U MBERS co ' ul C ' AG E 7 PL T oo Z co z m u, cf (, P + 1. AGE 8 P L T +\L M. o co -,z m> -_-_, cc w Co FI GURE 5. C TI C )- --1.co + -1 CL + CC W - 1 C L -1 L SPA UMBE RS K z C C,- m ill LID ' C ,.-I CC > zorocuic co J Z CT > zorcow C LL

20 7. o 7 ) o + A Cr 1,1 In 7' i 7 3 un L SPA UMB E RS + AGE tl PLT C C Z > z Z C W IX VI _J c D ul Z Cr. Z r C W l C U) 7 U) FIGURE 5. CTI UE D. + + D L S PA U MBE RS l L S PA UMBE RS F ) r ce, CI + 7 '7.. U + ' U) n C w : C 7 Cr + '7 ) I in.., _12 CL> ZrCL1.11X(P J Z 2> zoreowcron U-

21 Appendix 1 Formultion of the Adptive Frmework Prmeters: - Yer-clss estimtes:i,1988 i = 5, 12 - Clibrtion coefficients for R.V. survey numbers: Ki i 5, 12 Structure: - turl mortlity =.2 - Effor in ctch t ge ssumed negligible - Intercepts not fitted - F on oldest ge (17) clculted s 4% of Men F (weighted) by popultion numbers) t ges 8 nd 9. - F on ges in 1988 clculted from the following input PR: Age PR Input C i,t i = 5, 12, t = Ctch t ge - RV i, t f = 5, 12, t = RV survey bundnce t ge bjective function: - Minimize EZ [obs(1nrv )-pred(inr it it V it )1 Summry: - umber of observtions = 8 - umber of prmeters = 16 2

Chapter URL:

Chapter URL: This PDF is selection from n out-of-print volume from the Ntionl Bureu of Economic Reserch Volume Title: Price nd Quntity Trends in the Foreign Trde of the United Sttes Volume Author/Editor: Robert E.