CM_1968_J_03.pdf (679.8Kb)

This paper not to be cited without prior reference to the authors International Council for the

Exploration of the Sea

c~]Yr.1968/Jg 3

Pelagic Fish (Southern) Committee

Report from the Eluefin Tuna Working Group Observations on the Size-Compositiom

of Eluefin TtL~a Catches from 1967 by

J. Hamre 9 J. Mauxin9 J. Rodriguez-Roda

&

K. Tiews

I. Introduction

Reference is made to the previous reports of the Eluefin Tuna Working Group (Statistical News Letters 9 Nos. 20, 26 and 38). Dr. F. Lozano⁷ upon his Ovffi request9 has been replaced by Dr. C. ^l1aurin~ The members of the "'lorking Group have continued

their viOrk by correspondance among themselves and with other tuna research ,\'lOrkers in the region. The present report deals with the data obtained for the fishing season 1967.

11. Ha terial

Reports on the catches and catch composition of bluefin tuna vTere sub:ni tted by the following countries: Denmark (Table 1)9 France (Table 2), Italy (Tables 3 to 4)9

NO~Nay (Tables 5 to 7)9 Portugal (Table 8), Spain (Tables 9 to 10), Turkey (Table 11)9 and USA (Table 12)0 The Federal Republic of Germany reports that the tuna fishe~

could still not be continued because of inavailability of fish on the usual fishL~g

grounds in the central parts of the North Sea.

For the first time it was possible to obtain size-composition data of Turkish bluefin tuna catches. The data were collected at the Istanbul fish market by the Institute for Hydrobiology of the Ista~bul University and submitted by Dr. M. 1. Artiizo The fish vrere caught in the sea of l-Iarmara and in the Bosphoruso Length measurements vrere taken as fork length by caliper.

~1r. O. Eagge reports that the Danisli catches were made east of Lres0 on hook and line except 1 tuna, which has been taken in stake nets on the north coast near Skagen. The hook and line fishery has been carried out together with trawl fishe~J

for herring. ~/Ir. R. Letaconnoux states that Table 2 refexs only to the catches distributed by the Cooperative ~1aritime Itsasokoa. The total French catch in the Bay of Biscay was 1,088 tons in 1967 "Thich is 10\.,rer than in 1966 (= 19656 tons).

According to Dr. R. Sara, Centro Sperimentale per l'Industria della Pesca e Prodotti del ]\'[are, Palermo, the data given in Table 3 refer to fish9 "'Thich vTere caught during the spawning time at the end of May and the heginning of June in one madrague. The sample is not a real random sample of the Sicilian tu.~a catch, because the data were obtained by different plLrchasers having shown different attitudes L~ selecting fish of the catches.

The Norwegian material given in Tables 5 to

7

is not quite complete for the southern area 9 because from 63 tons of tuna landed in district ^No.\~I

(Rogaland), it vras not possible to get weight slips. The total Uorwegian tuna catch in 1967 ,·Tas approximately 19500 tons. The NonTegian weight-composition data (Tables 5 to 6) were recalculated into lengch-composition data on the basis of a K-value of 2.15, calculated from a sub-sample of length/weight measu.~ements.

Dr. Vilela reports that in 1967 only three traps have worked on the south coast of Portugal instead of five as formerly. Only a few tuna were caught on the west coast. Dr.

J.

Rodriguez-Roda gives in Table 9 the Spanish size-composition data from the madrague catches at Barbate hy his Ovill measurements. Bluefin tuna catches could be collected by number of fish fnr the whole season at Barbate, Sancti-Petri, Tarifa and La Linea (Table 10). The total Spanish tuna madrague catches in 1967 was approximately 3.010 tons, distributed so:

Barbate 1,836 tons; Sancti-Petri 767 tons; Tarifa 338 tons and La Linea 69 tons.

According to l>'fr. F. J. Mather III of vioods Hole Oceanographic

Institution the US bluefin tuna catches are grouped according to date of landing (Table 12), and some samples may include fish caught in more than one ,.,eek.

The catch distribution by area a..."1d ".-;reeks is shown in Table 13. JYIr. Mather reports that this season 1\TaS much more successful tha..."1 that of 1966" However, the tag return rates indicate an extremely high fishing ratio. ^ll~other alarming

factor is the very poor ShOv.ling of age I fish, the worst in years (Figure 1).

In Table 13 T>'fr. Mather has given some effort data based on number of days fished by a selected group of ^seiners~ and their corresponding catch. These data are not complete 9 since they do not cover all the boats.

Ill. Comparison of the Catch-Composition Data collected in the Different Countries

I.

~E~~~~_!~~~_~~~~~~~~_~~~~~~~

As seen in Figure 29 the size composition of the Norwegian t~"1a catches has remained more or less unchanged since 1964. The very slight increase in length shows that this old age-group, believed to be the 1952 year-class, is now approaching the ultimate length of bluefin tuna. The average weight is however still increaSing with some 15 kg a year. Practically no recruitment of younger fish occurs.

The oldest fish occurring on the Spanish coast correspond with those found on the NOTIvegian coast. Apart from these 9 fish of the size corresponding to the year-class 1958 predominates again in the catches resulting in a second mode in the length-composition curve. Another mode is formed of fish belonging

to year-class 1961. The fish of the year-class 1952 seem to have used 2 to 3 weeks to migrate from the Spanish to the Norwegian coast. It has had its peak of abundance on the Spanish coast in the 29th week and arrived in full strength during week 31 and 32 on the Norwegian coast (Tables 5 and 10).

2. ~~~~~~_§R~~~~_~~~_~~~~~~~~_~~~~~~~

In general, the catches in Turkish waters contain fish of the same size as in the other two fisheries. The maxima in the Turkish length-composiion curves do, however, not tally with the Spanish and Norwegian curves. Although the size of the Turkish materials is rather small, the result is astonishingly similar to that observed ,,,hen comparing the Italian catches of 1965 and 1966 vTi th the

corresponding Spanish and Norwegian data. Also in this case the age

composi tion of Italian madrague catches was different by shmving maxima where the Spanish and Norwegian curves had minima. The findings, although very preliminary, indicate that the relative strength of year-classes of bluefin tlxna in the Mediterranean Sea (including its adjacent seas) and in the East Atlantic differs during the period urlder survey, suggesting that the bluefin

tuna forms two morGor less distinct stocks of fish in these areas. In view of the importance of such a conclusion for the management of the bluefin tuna

stock9 it is highly recommended, to collect further and greater amounts of data, in order to be able to draw definite conclusions in this direction.

3

^e ~~~~~~::_!~~~_~~~~§~~_~~~~~~~

It is unfort~~ately not possible to recalculate the Italian weight-

composition data into length-composition data because we do not know the condition factor of the Italian fish. Therefore only the weight compositions of Italian and Nonregian catches can be compared. No conclusion can be drawn from this comparison in the direction discussed under 2., since the differences in the size composition expected are too small to be reflected by comparing uncorrected weight composition curves. In general, previous findings can be confirmed that the Italian catches consisted as the Sp~~ish catches of more age-groups than the NOTIlegian catches (Tables 3 a.."YJ.d 5).

- 3 -

4.

~~~:_!~!~_~R~~~~_~~_~~~~~~~_~~!~~~~

Contrary to the previous years~fish of age-group I was absent in the US catches, w~~ch consisted as in 1966 of fish of year-classes 1965, 19649 and 1963.

Mr. Mather III reported that in 1967 another 16 fish, which were tagged on the US coast, were recaught in the Bay of Biscay. 11 of these had been released in 1966 9 and 5 in 1965. The period in which the latter crossed the ocean cannot be determined, but

4

of them were released in the same period and area as 2 'tvhich 'were recaptured in the Bay of Biscay in 1966. During 1966 and 1967 a total of 31 tuna i'Tere thus recaptured in the Bay of Biscay and had crossed the Atlantic. As already stated for the previous years the size

composition of the US b1uefin tlLna purse-seine catches was completely different from those made on the Spanish and Norwegian coas1&.

IV. Summary

---

10 The size composl~lon of b1uefLn ~xna catches made in various countries has been compared. The Norwegian tuna catches were likely composed of fish of year-class 1952 ,vhi1e the Spanish catches were composed of several year-classes wherein year- class 1952 predominated again, but showed a much lesser relative abundance in 1967 than in the previous years. Fish of year-class 1958 and of 1961 vrere other important groups of fish in the catcheso

2. The age composition of Turkish hook and line catches made in 1967 was different from that of the Norwegian and Spanish catches. Another hint is thus given of the existance of a difference in the relative strength of year-classes of bluefin tlma in the East A t1a...ntic and in the Mediterranean Sea

(including adjacent seas) suggesting that bluefin tuna forms ti-TO more or less distinct stocks of fish in these areas.

Further and greater amounts of data are necessary to draw definite conclusions in this direction.

3. The age composition of US bluefin tuna catches 'vas found again completely different from that of Spanish and

Norwegian catches. In 1967 fish of age-group I was entirely absent in the US catches, which is for the first time since the beginning of the fishery. In 1967, another 16 b1uefin tuna? tagged in the viest Atlantic, were recaught in the Bay of Biscay, bringing up the total of fish having crossed the Atlantic since 1966 to 31.

Hamre, J. 1964

& Tie1nTs, K.

Hamre9 J. 9 1966 Lozano9 F.

Rodriguez-Roda,J.

& Tie1nTS 9 Ko

Hamre, J ^{0 ,} 1968 Lozano, Fo,

Rodriguez-Roda 9 J.

&

Tiews9 K.

References

"Report from the Bluefin Tuna \'lorking Group.

On the size-composition of tuna catches from 1956-62". StatoNevTs Letters 20;1-439 Cons. perm·.

int.Explor.T![er.

"Secon' report from the Bluefin TUna "'Jorking Group. On the development of the bluefin tuna

tli~a fisheries from 1950 to 1964 and further observations on the size composition of bluefin tuna catches". Stat.ilTe,".1's Letters, 26~1-34,

Cons. perm. int • Exp10r ⁰ }1er. --

"3rd Report from the Bluefin T'..ma vJorJr,ing Group - Observations on the size composition of bluefin tuna catches from 1965-1966". State News Letters,

2§.~1-27, Cons. perm. int.Exp1or.}1er.

Rodrig~ez-Roda9

J. 1967

Rodriguez-Roda, Jo

1968

Tievs, K.

1964

"El dt-6n, Thtmnus thyr..nus (L.) del sur de Espana, en la call1PaTIi81illa'drabera ctel ano

1966

^11• Invest.

Pesque;a, 31(2)~349-59.

"El atv.n, ~TQrmUS thynnus (L.) del sur de Espana en

la

campana almadrabera del

anQ 1967

y estudio

a.e la evolucion de la pesqueria de :Barbate". Ibid. ,

( DJ" _{_} DT'e _{-.'"_} c. _.~)l~/O <:! )

!1:Der Thv-llbestand (Thunnus thyrillUS) (Linnaeus) in del.' Nordsee, seine WandertL~gen9 seine trans- atlantischen :Beziehungen 11..1'ld seine Nutzung durch die deutsche Fischerei". Arch.Fisch.Wiss.,

XJ;!(

3): 105-48.

Table 1. Weight distribution in %Q (smoothed) of

38

bluefin tuna caught in the Kattegat by Danish fishermen in

1967.

The "\treight-group refer:s to gu.tted fish (kg)

100

Group r ⁱ

I

195 o I

200 7 I

205

¹_-

3 I

_I

210 7 I

215 o

I

220 7

!

225 ~g

^I

230

235 26

240 66

ⁱ

245 73 i

250 33 I

255 39

^I

260 67

^I,

265 60 I

270 60

^I

275 73

1 ⁱ

280 73 I

285 53

290 53

295 52

300 39

305 39

310 20

315 7

320 20

325 20

330 13

335 13

340 7

345 7

350 13

1,000

- 5 -

Table 2. BluefL~ tuna catcheR at St. Jean-de-Luz (France) in

1967

in kg (d.ata given by Cooperative Maritime Itsasokoa).

1LV.

26.7".

2.\7I.

9.

VI.

16.'110 23·VL

30. 'ill.

7.TI1o

12.

^VII.

19.VI1o 28.VIL

3·VIIL - lLVIII. - 18.VIII.

25. VIII. -

LIX.

S.IX.

15·IX.

22.IX.

29.IX.

])ate 18.V.

loVIo

8.VL

15. VI.

22. \TL

290 VI.

6.VII lLVI10 18. VII.

27·VIL 2.VIII 10.VIIL

17.YIIL

24.VIIL 3LVII1o

7.IX.

14.IX.

21. IX.

28.U:.

5·X.

6.x. 12.X.

13.X. 19.X.

I

T o t a l __

~~~

Tot a 1 Fish below"

30

kg

11

9

248.5

3,473 32,275·5 459583.5

269819~5

21,057

29,636

13,988.5 68,521 16,299.5 22,593 291920·5 41,345.5 108,927 108,430.5

48,563·5 34,399·5 42,847·5 33,858

8,701 1,787.5 9,903 760,178.5

1if e i g t h

Fish above

30

kg

3,254

2,402

20,534 27,467

53,657

I

-1

Table 3. irleight distribution in %0 (smoothed) of 558 b1uefin tuna caught

in Sicilian madragues during May and June 1967. The i<Teight- group refers to ungutted fish (kg).

Group %0 Group %0

25 1 245 12

30 6 250 16

35 12 255 15

40 13 260 15

45 16 265 19

50 27 270 16

55 48 275 12

60 61 280 13

65 49 285 11

70 30 290 5

75 28 295 6

80 44 300 14

85 64 305 16

90 60 310 11

95 36 315 6

100 17 320 4

105 9 325 5

110 5 330 8

115 4 335 7

120 6 340 8

125 6

I

^{345 10}

130 5 ¹ 350 9

135 7 355 7

140 8 360 4

145 8 ^I 365 1

150 8

I

370 0

155 6 ⁱ 375 0

160 5 \ I 380 1

165 6 385 3

170 8 390 3

175 10 ¹ 395 3

180 11 ^I) 400 3

185 8 405 3

190 5 ^I 410 ¹

195 4

I

415 0

200 5 ^'I 420 1

205 11 425 1

210 13

I

430 1

215 11 ^I 435 0

220 9

I

^{440 0}

225 7

I

445 1

230 7

i

450 1

235 11 ¹ 455 1 .

240 12

I

460 0

I

1,000 1

- 7 -

Table

40

Eluefin tuna catch of Sicilian madragues in number of fish caught in

1967

Madragues stationed

I

in: Number

J

Oliveri

105

(below·

80

kg each) !

I

Trabia

650

Punta Raisi

2,800

Scopello

81OX)

Eonagic.

&

So Cusumano

(one madrague)

2,450

Favignana ^& Formica ('GWO madragues) Capo Granitola xx) :Harzamemi xx)

7,500 450 70 14·835

x) Note that Scopello have lost almost

20

days of the fishing season, for the delay on its settingo xx) Madrague of the "back period".

I

Table 5. Size-composition (kg) of Norwegian tuna catches south of 62°N by smoothed weight frequency (per mille) in 1967.

Group

w'

vleek Numbers

I

1J[eans w

30

jl 32 33 34 35 36 37 38 39 Total ^I

72 93

77 99

82 105

92 119

97 125

102 131

117 150

122 157

127 163

132 170

137 176

142 183

147 189

152 195

157 202

162 208

167 215

172 221

177 227

182 234

187 240

192 247

197 253

202 260

207 266

212 272

217 279

222 285

227 292

232 298

237 305

242 311

247 317

252 324

257 330

262 337

267 343

272 350

277 356

282 362

287 369

292 375

297 382

302 388

307 395

312 401

317 408

322 414

327 420

332 427

337 433

342 440

. 28 14

\14 114 42

1 56

98 139 111

; 70 28 14 42

i 42

1

28 28

1

28 [ 84 56

I

⁵⁶

114

1 1

1 1

1 2

1 2

3 2

5 3

6 4

8 8

16 11

24 12

30 16

41 26

55 39

61 45

58 54

62 67

74 73

78 75

74 77

71 74

64 70

55 68

47 61

36 51

30 40

30 30

26 25

19 21

12 14

6 10

3 7

3 6

3 5

3 3

1 1

1

1

1 2 3 7 14 20 17 20 44 69 76 77 81 85 89 85 68 49 42 40 32 25 21 13 10 .8 4 1 1 1 1 1

1

1 1

3

4 4 6 10 17 23 25 30 39 49 59 60 60 65 72 73 69

64 54 45

39 27

33

21 16 10

7

5 4 3 3 2 1

1 2

1 2 1

2 1 2 2 2

5 3 2

5 5 2 9 5 5

11

6

8

14 10 10

20 16 13

23 23 16

32 27 28

36 25 42

40 27 49

76 37 50

98 51 45

80 61 42

62 64 42

65

65 54

74 72 69

58 75 60

45 65 51

56 51 61

54 46 70

36 41 63

23 32 49

20 31 36

20 33 24

14 27 19

9 24 22

7 23 20

2 15 14

8 9

5 4

5

1

5

¹

4

2

2 4 3

5 2 2

1 1 1

1 2 1

1 1 2 1 2 2 1

3 4

1

5 3

4 3

6 3

9 5

12 7

16 14

17 21

18 24

24

33

36 45

42 52

41 51

45 47

58 49

63 55

52 60

48 60

58 53

61 51

57 46

49 38

42 41

42 47

42 41

40

33

32 21

20 19

13 10

11 8

10 8

8

5

5 5

1 6

6

1 3

x

x

x x x x x 1 2

3

5

7

9

12 19 26 30 36 45 53 58 61 63 64

65

62 57 52 46 40 36 31 25 20 17 14 11 9

7

5

4 2 1 1 1 1

_. 9 -

Table

60

Size .. composition (kg) of :tTor..:regian tuna catches north of

63°H

by smoothed weight frequency (per mille) in

1967

Group Heans vleek Numbers

"VI i.tl'

30 31 33

Tot a

1 I

---I

189 4

195 13

202 13

208 7 4

215 15 13

221 7 25

227 13

234

8

240 7 21

247

22

38

253 36 54

260

57 50

266 72 38

272 57 34

279 50 42

285 108 54

292 165 54

298 129 50

305 64 15

311 29 104

42

84 42

83 167 83

317 29

e7

42

324 43 54 84

330 43 37 42

337 43 33 42

343 22 29 84

350 21 42

356 17

3 8 8

13 5

18 8

5

18

35 41 5 4 4

4

7

Q .-

7 6 7

o

1

o

2 4

9

9 7 2

l)

2 6

5 40

I

38 30

I i6

^I'

LH

I

152 157 162 167 172 177 182 187 192 197 202 207 212 217 222 227 232 237 242 247 252 257 262 267 272 277 282 287 292

I

10

---1'- _1-0-~. ^{_ - - [}

362 13 42

369 4 84

375 42

n

35 60

6

Table

70

Calculated length data - length frequency distribution - . - - - - in per mille for Norwegian tuna catch8s in

1961

(K =

2015)

r

i Length Groups Southe:rn Northern

I cm area area

I r - - -

I ^{205-209 3}

,~

.:...1.

210-214 9 16

I ^{215-219 22 33}

^I

I

220-224 50 26

^I

I

I

I I

225-229 102 122

_I

1

I ^{230-234 144 114}

I I

235-239 181 214

240-244 171 215 I

I

245 .. 249 135 152 I

I

250-254 93 79

^{I I}

I 255-259 52

²⁶

I

I

260-264 24

¹

I I

I

265-269 1

^I

I

270-274 2 I

I

275-279 1 -~

'lIable 80 Bluefin tuna caught from the south coast of Portugal madragl1es in

19679

specified by (IJeight-group (kg) .. ---_.,---_._---_._------. Months May June July AugL1.st

---.---r--- >

90

I

50-89

Atnn Atuarros

197

116 886

167

82 28 122 31

. Humber QL_:Lish ________________ __ _1 __

3_0-~~_1--.

10-_29 A1bacoras

I

Cachorretas <10 --t---- Cachorretitas ~ ____ ----_-t-___ --_-_ 1 3

14 3

1

l

Tot a

1 _L 1,366 263_1 __ 4 =

^--- 3

15

Tot a 1

279

162 19012

198

19651

---~

Table 9. vleek1y size - composition in

%0

(smoothed) of Spe,nish madrague catches at Barbate in 1967. CD

=

pre-spawning fish; R

=

post-spawning fish) (Rodrigu.ez-Roda 9 1968)

------. .--- ----...,-

D D D D D R R R Tot a 11 ---

...

... __ __. vI eek No. 19 20 22 23 24 28 29 30

~ngth-gr()u:p-...--.- ~---.---~---

---4

----..---.---~---

115 - 119 95 1 0 120 - 124,5 2 1 125 - 129,5 1 0 130 - 134

9

5 6 2 0 1 135 - 13995 13 5 5 11 0

I).

140 -

141).,5

1 13 9 6 21 0 2 5 145 - 149,5 3 19 5 8 21 0 5

'7

150 - 154,5 5 39 5

11

32 8 1 6 13 155

~

159

9

5 8 59 23 17 52 19 6 6 22 160 - 16495 8 60 37 29 63 19 13 19 27 165 - 169,5 4 42 27 37 52 15 11 32 24 170 - 17;1r 95 3

2fT-

18 29 32 15 7 22 16 175 - 17995 6 16 18 19 21 30 12 34 16 180 - 184,5 7

11

23 27 63 69 24 65 26 185 - 18995 8 13 32 48 105 89 37 68 35 190 - 194,5 13 24 50 58 84 85 54 76 45

1-' I-'

195 - 19995 31 32 73 67 104 104 70 101 61 200 - 204 95 48 42 105 104 146 123 75 102 75 205 - 20995 53 52 132 123

114

104

77

83 78 210 - 214,5 50 41 105 84 62 70 75 63 64 215 - 21995 42 25 73 47 21 58 62 55 47 220 - 22495 48 26 64 39 58 50 49 43 225 - 229,5 79 45 36 31 39 66 44 53 230 - 234,5 97 72 27 30 23 93 44 67 235 - 23995 114 90 37 29 27 98 36 75 240 - 24495 140 91 32 34 27 75 29 74 245 - 249,5 120 73 27 51 15 44 26 59 250 - 254,5 68 46 23 44 4 25 19 37 255 - 25995 33 20 14 19 13 10 17

260 -264.5

1= 11 6 5

5

~

2

~I . 265·- 269,5

1

4 t}70 ~~2~4.5

____ . ______

1 ---.---~--- ---.-~.--- 228 279 55 161 24 65 315 154 19 281

--~ --~------____ --.0 __

-

1,vesk No.

18 19

20 21

3~~

35

36 I 37

L

I

³⁸

Table 10. Spanish bluefin tuna catches (by number of fish) at Barbate 1 Sancti-Petri1 Tarifa and La Linea by weeks in

1967

(n

=

pre-spavming; R

=

post-

spa~ming fish) (Rodriguez-Roda1

1968).

l4.V. 20oV.

Total =

16

₁

416

2 R 2 R

- 13 -

Table 110 Size composition in ~ (smoothed) (fork length by caliper) of Turkish bluefin tuna catches in 1967 (landed at the Istanbul fish market).

I

Length

I I . ···-1

: cm

I

January February! I1arch I April }/I'..ay-December

~--

.

U) ^~- I I

I

90 ~5 ^I

---

100

14 34

27 7

Total 2 6 2 5

140 7 2

J-45 13 2

150 7 7

2

155

7

14

4

160 20

7

6

165 6 20 14 7

J.70 12 13 20 8

175 6 13 41 10

180 6 13 15 4 54 16

185 30 26 30 9 47 26

190 59 39 15 4 47 30

195 70 63 7 4 68 40

200 71 82 22 22 69 51

205 77 57 37 39 41 50

210 83 51 59 35 48 53

215 83 51 66 48 68 62

220 78. 39 66 90 48 66

225 60 45 81 90 34 64

230 54 51 66 69 47 58

235 54 45 44 98 47 61

240 49 39 74 120 34 67

245 59 63 118 95 34 77

250 53 76

I I I

78 41 76

255 24 57 66 60 34 50

260 12 50 44 35 27 31

265 6 26 37 31 20 22

270 15 31 7 12

275 7 7 17 7

280 6 13 13 4 7

285 12 7 7 5

290 6 4 3

295

9 3

300

4 3

305

2

310 6 2

315 12 3

""'20

)

6

j

1~000

¹

11

,000 11,000 1,000 1,000

l'OOO~

n =

42 . 39 I ^{34 58 37 2 1 0 .}

Length cm 50 55 60 65 70

75

80 85 90 95 100 105 110 115 120 125 130 135

Table 12. Weekly size composition of US b1uefin tuna purse-seine catches in ~ (smoothed) (fork length by ca1iper) off New Jersey and Long Island for 1967. ---~.-----_._--- __________________ 1tL~.'i.. k s __ . 27 -28 28

-

29 29 33 34 35 36-Tot a 1 --- 1 2 14 5 3 46 12 19 4 29 11 7 116 32 142 36 21 33 19 13 120 45 310 71 146 96 85 57 130 102 287 58 354 249 187 190 220 204 138 34 354 285 183 261 220 207 63 30 125 139 87 146 99

98

34 68

36

59 63 20 49 7 175 38 90 93 12 69 245 39 87 88 11 76 200 26 47 43 4 46 73 1 19 13 15 6 4 21 3

9

10 37 8

16

8 39 9

17

2 19 3 7 4 1 1

. ___ 140_._

---~---

1,~~~ ~l.~~~ -~.~~~ ]-- ~:~~~-- J

1,000 11000 11000 1,000 __ ._ .. _ n :: ____

J 67

128 12 260 ---_. ---~..---

\'le

26 (July 1) 27 (July

2- 28

~uly

9-1 29 (July

16

30 (July

23

31 "uly

30-

32 (Aug.

6-1

33 (Aug.J.3- 34 (Aug.

20-

35 (Aug.

27- 36 (Sept. 3- Tot a '---

ek

----- s)

5) -22) -29) Aug. 5) 2) 19) 26) Sept.2) 9) 1

Table 13. Catch (in short tons

9

above line) and effort (in days fished, below line) in the ---'--- north-western Atlantic bluefin tuna purse-seine fishery for 1967 season? by vleeks and statistical areas (Figure 1). VA, C, D

&

near 39°00'N,74°00'11}'

VB

lVC IVD 0 0 I I

---.

]--- IIIC

9

D & near In

~d.south

of lVE~_J.~30~N.67"45IW ~ amd"--~ __ T ~ t a 1

2 I

195.9 195-.!.2 9 9 17.0 ""b 17.0 6 1- 61 .4 1 18 •1 479'2 4 1.3 17 8.3 126.,2- 1 14 13702 "-TS- 0 129.<1- 0 "5 -

1

10 0 1-.. 2 9.4 I 17 0 0 220.7 I "2 6 0 22007 I -lO- .113. 2 536.9 11 29

O

710.1 I -"38 172.6 5 2 5.3 579.9 5 20 25 0 0 28.5 "5 "5 20 0 7.8

2.~.!2

"5 2 37 0 31. 9 1 --4- 0 .21.9 '4 9

---f--- 169~1_

b 00 5.!.1 h.2j0& 31.9 11 70 84 -6- 0 7.8 I

Q

J 2.?55~:9- 10 2 2 185

---, ---

I-' V1

~

NEW

I I

B

C I ^{7

IN

01 SABLE

o

o I'-

lD

I

I

10))0 FMS

/

~ ^{I D I}

^,t£

~F ~ ^___ L~ J~ /_ 40o~

BluEFlN CATCHES

JULY ~

AUG. ~

SEPT. ~

FROM

HO CHART 5244

70°

- 3 5

⁰

Figure 1. Map showing fishing grounds of US bluefin tuna fishery.

J:3/Hamre et al.

"I""

200

100

,', '"

..

" ,

~ ~ ...

-: USA -: nJRK£Y -: NORWAY -: SPAIN

~

= IrALY

,",

\ \

\

\

\

\

\

\

\

\

/ \.. .=;\\

\

O

\/:: \.... ^{... .. ,,~" .... ','}

~'.----'

^.. _-..,.~

~

"'t

I ,

"

100

:

"

I \

I \

I \

I./\. \

\

\

,

\

\

D .:;.

>:

100

I I

\

\

\

\

I \

,

'. .

^{" ' :} _,

~\

_I ^{. \ \} _\

o

-i----.:..::...---... _:

~~

_~ ... ". _-~.~-,

100

A."';.

~: .. , '~""

,:,.

...

... a."

o 40

80 120 160 20f)

" \

,

I

,.-.,

"

240

" \

"

... ^\ \

"

,

' ^...

3,127 4,531

372

1,341 8,332

379

23¥

3,292 T.174

152

1.466 270

6,652 1,281

280

Figxre ? Size composition of bluefin tuna catches made in USA, Turkey, Norway, Spain and Italy.

J: 3/Hamre et al.

1964

1965

1966

7967

300 LENGTH cm