•

FISHERIES RESEARCH BOARD OF CANADA Translation Series•N

• ishing techniques in the : uha:

Original Fangmethoden der «ThunfischereL From: Protokalle•zur Fischereiteàhnik.,,No'. 42, Vol. Pp: 197.-279.

Translated by the Translation Bureau (PJW) Foreign Languages Division Department. of the Secretary of 8taté of Canada

Fisheries-Research.Board. Of Canada Biological Station, St. Andrews; N. 1967 DEPARTMENT OF THE SECRETARy or ;TA e • SECRÉTARIAT DigTAT TRANSLATION BUREAU BUREAUDES ,TRADUC'TIONS FOREIGN LANGUAGES DIVISION DIVISION DES LANGUES ÉTRANGÈRES';'..

' • • , . . • • • 'rout% No; DEP ArtTMENT. • 'DIVI.5IPN/BKANCq • vo -in No MINISTERE • •. DIVI .SiON/DIRECTION • 769-18-14 Fisheries .Editorier . • Ottawa • ' Researoh Board bUrt NOb ' • LANGUAGE TRANsLAToR (I P' TIALS) DATE NOTitE LANGUE • TRADUCTEUR ti.NITIALLb; 1111-1 , German pew 18.8.67

:Tranàlation. of artiàle . -ptihiished 4 àeparate-PUbilcation byy

"Institut-für eangtechnik7 Hamburg' •.(Institilte for Catch Technilà,.flamburg) .

. 't - • •

, • ,.. :.•• :i .„ . : ■ /7 --« / ' (. ,,,•-!•.1.( i . , • ' 1 , , ,. i ..f ' ' • . - 1 - s' '• 1 . '..,1 1 1 i! /, ,U'.e. y• 1 . „ • • • . .. . v . rpeW4meDs----eli.-.E! • . :.. .I • • - . .reA . .

(Fan'graethoden der Thuneiseherei)

By Av Brandt

Page •No.

Original Trans- text lat ion

Introduction • • 198 • • 3 .

. Catch methods • 202 11

- - A Harpooning and. shooting • • • 202 . 12 •

B Catch after stupefying . • • 205' >. 16 .

C Line with hooks • • 206 • 17

1 • ole-and-line with live bait . 206 : • 18 2 Troll--line fishing • 212 •. • 26

see s -2oo— io . 31

3 Delft lineS 4 Longlines.

D Ripping hooIçs . .and

E Catch constructions andiargeslz -ed - fishing traps 1 Catdh Chambers 2 Dalinnes 236 3 Madragues .

4 LarÉte-sized fishing traps madsicif .moddwOrk''.241: 5 Large-sized fishing traps made of netting 243,: 75

F Tràwl nets • 244 79

G Seine nets 246

H lurrounding nets - ,247 ,81

J Dip nets -264' : 111

K Gill nets 268 . 114

L Entangling nets . 270 116

Importance of various fishing methodà 270 118

Bibliography' 275 124

Translation of German and Scandinavian titles 129 - 'fishing. • is. regarded as one of thé important.: P:4 les

branches of the fleing industry'in the World .. ' The • • - • : . , • ,ketting prospects for tlina•must le'describes 4- sis the:

-oaSe eaSo with many kinds of crabs.--Has preauMably' - favour- able - for a long time to Come. - goreciver,.the fishery for

8Orrie ~ f the. fishes claSSified as'tuna:.(see bélOW) ja•nOt' confined to the vicinity of tha.doest:and. thuals:mot tie'd , •to thé extensive territorial - regions it is:rathera pelagie • fiahery which' may:aSsuhe the forma .of a. genuie. high4-saa- fiSher3r.-

The world catch of tuna ha s increased considerably during the last years. Local small fisheries developed into large fisheries with a world-wide 'bade's. rlhis required

not only a considerable financial outlay for ships and • •fishing gear, but also for support bases with harbour installations, cold storage facilities, ice factories, •processing plants, and transportation facilities. The world catch of tuna has increased from 500,000 tons in 1953 to •one million tons in 1963. It is expected that this increasing tendency will continue also during the next years in spite of the retrogression of the average daily catches in indivi- dual regions, and that in 1970 or, at the latest, in 1975 approximately 1.5 million tons of tuna-like fishes will be caught (compare Chapman, 1962). If in the fieery:of-the iedéral'RepublWWe of tuna, we have in mind exclusively thebliiefin thynnus) of the English-speaking.- fisheriea,.'the:Otchof which is carried oUt -bY oUr cutter *iShery:at.tiMes:with varying sticcess in the -(Tiéwe; should not be forgotten that in the fishingilndUStrYi- . We understand under "tuna" a number.ofsdiffererith -, Speoies.- The International World Tuna gonferencee ,Orranged in by FAO,speaks therefore, to be eUre'very carefullY;:cif - ", bonitos and'related species".: Eçdàiever, of greate: economic importance are only the.follôming spegies:i: rerMan name -English name :SCIentifinaMe • Roter Thun Bluefin Tuna. . thynnus. Gelbflossen-Thun Yellowfin:Tlina •Th. albacares

Weisser Thun . Th. alalunga Grossaugen-Thun - Th, OhesUS: Echter Bonito •Euthynnils. pelamis

These 5 fish species, together with the "nongenuine Bonitos", little tunas, alletteratus (see below), are frequently designated as "true tunas". But there are still very many other tuna-like fish the tuna fishery is interested in. The following table presents a general survey of the tuna-like fish of interest from an economic standpoint, including the ones alre&dy mentioned as of chief.eoonoMic• iMpàrtanW"..,

A. True Tunas

.Roter Thun '(Bluefin tuna, ,una,- tunny,- horse mackerel, great albacore, 41ton rouge).Thunnus (Linnaeus-) tilynnus

Distribution: world-wide in sub-tropical and warm-

tempered seas

Sub speC•es: a) Th. thynntis UinnÈteusAtlantic, NE Pacific • '.b).Th.- tilynnus-.orientallà. and Schlegel).

Indopacific, Australia, South Africa-.

Synonyms: Thunnus argehtivittatus W.. .Atlantic Th. Saliens, California Th. maccgyii,.Australia

1I am greatly indebted to Dr. G. Kreft of the "Institut für Seefischerei" (Institute for Se a-fishing) for letting me have the.following compilation. After the German names I gave •in parentheses -- as far as were known the English names according to Tibbo and McKenzie (1964) and after the .9.sign the French names. 2. Weisser Thun (Albacore,..1Ongfin,tlinsa, loneinnédtUna,. t Germon, ThOn blanci;)i ThunnUs. alglunge

Distribution.: world-wide in aubl- tropical -seas . and . - . - ,deeper Water :layers...of:the- . tropics:

Sub-spcleal

SynonYms: aermo GermoGermà (or ThUnnàs)Thunnus) ff,f.rio, 'Eninaciftc: :Pacific

Gelbflossenthun :(, Allisoni3.:64nnY,

albacore, 4 autuMn Albecore). ,.). Thtinnua. _ _ _ . . albacares (Bonnat erre)

Distribution: world-mide in, tropipal-beas . - 31lb-species: -- •

Synonyms: Thunnua (or' Neothunnua) macrOpterus;', Indian Ocean, Pacific

4. arossaugenthun (Bigeye tuna); . Thunnila Obesua Lowe

Distribution: world-wide:in tropical, in-part'alao sub-tropical aeaa

Sub-species: ynonyms: Thunnus (or Parathunnus) mébachi; Indian Ocean"

tt tt sibi, Pacific 5. 3,hwarer Thun (Bladkfih' tuna, >13ermudii Atlantic , blackfin bonito) , Thunhua atlahtioUa ( Le aa on)

• ".. . • . • 6. • :Lang Sehwanz- Thun (.49 ngt 11 or • "No rtherh: . . . . . . . . . . . • • .. • . •. •-•..

Distribution: Red Sea, India to Philippines, Japan, - E. Australia

nonym s : • •Kishionella tonp..gol

In the statiatiealtableS;.the -làhgtail-tUnalas4à.11,Y - included with the bluefin tuna. listed as No.

B. BOnitus (Little tunas.and skipjacka)

1. Echter Bonito'(Skipjack tuna,-ogean bonito,'Stripe bOnito,: - 4.Bonite ventre rayé), Euthynnua (KatsùWônus) • a pelamis (Linn.)

Distribution: world-wide in tropical seas.

2. Rackenstreifiger_(Unechte_ .r) qonit_o_ (Little tuna, false albadore, bonito, + Thonine) Euthynnus (Euthynnus) alletteratua (iafinesque). •

Distribution:- Mediterranean $eu , Tropical East and West • . Atlantic. PaAifisdhen F.alaChtr_Bp.nito (Black skipjag (Eullynnus) affinùâ (Cantor):

Distribution: vëry Widely in thf: Indian and. Pacifie °cep::

Synonyms: Euthynnusf.yaito (Tapan; . • BaWai:i . s'OUthHSeà - Islands

4. Mittelamerikaniacher Bonito, EutWnUa. "(Euthynnua).*lineatlis (Kishinouye)

Distribution: East Pacific California

C. Pelamiden (Pelauds)

1. Pelpmide (Common bonito, , skipjack, horse mackerel,. 4 Bonite tà . dos .raye) . Sardamarda (Bloch)

Distribution: Mediterranean Sea, Black Sea, Atlantic

2. Indoezifischer Pelamide (Oriental Bonito), Sarde orientalis (Temminck & SchleMel)

Distribution: Indian and Paoific Ocean, in tropica l. and - sub-tropical latitudes

S. Chilenischer Pelamide, Sada chiliensis (Cuvier & Valenciennes)

Distribution: Puget Sound to Cille Sub-species: S. chiliensis nhiliensis (C & V) qouth America ” u linealata (Girard), Calif., Mexico 4. -PerUan1Scherlamide(Bonito) Sarda velox (Meek P. 201 Ac Hildebrand)

'Distributicin: Lower Caiifornia:to Northern peru

5. (togtobth tUna), 'LlymnOsarda :Unieblor .(4epPell)

Distribution: Red Sea, Laccadive Islands to Japan, East Australia, Marshall Islands

6. LeLpinn Bonito, Cybibsarda e•egans (Whitley.). . .• Distribution:_ Coasts- of E and W Australia between ' • 20 and3,5°:S • ' . 1 • - •

7-, Plain Bonito . ( 4.Talomète),,Orcynopàis,unicolor (Geoffrey:- . St. Hilaire • -

DistributlOri: Méditerranean . See,' Sub-'tropiCal. East. -Atlantic to • Senegal •

8. - Allothunnus fallai Serventy

Distribution: Only few•spécimenS known: Auckland Islands, New Zealand, Tasmania, South Africa Dt„eq.Oete4 0 12.'WX

1. FyngutIMILkele (Frigate mackert ,thazard UElbépb4

Distribution. world-wide in tropicEll an

• -SynOnyMO:'

2. Frngattmakrelejükieroqhei'(Ris*i)

Diatribution: As b 1, but in - Vicinity'ef'ôoaSt s.. Occurrences in the-AtiatticiqUebtiOnablé •

3ynonyms A thYnnoidéS ,-. LL4fflemphsiA -

E. Double-lined Mackerels

Only one species: Gramhatorcynus bicarinatub (QUOy '8"c CaiMard)

Distribution: In the.Indo-Pac#10,»but.infréquént: . ..

The fish mentioned here differ considerably with regard to their economic evaluation, their occurrence •and their behaviour. Moreover, it is a known fact that in many-- if not all -- species of fish the young animals may differ in their behaviour from that of the old fish. This, of course, has a bearing on the catch technique and if here we speak quite generally of catch methods in tuna fishing, we must, - 11 -

'however, not forget that the.individualmethodg -arg . freqüently; suited only for one pat of. the fish degignated as tuna:

Catch Methods

• Th&ifollowing'catch methods are regarded as the« most important ones in the industrial tuftafishery (Rosa,; 1963)*:

Lôngline 'fishery' Purse seine fishery ' - with*liVe bait .

The world yield of the tuna fishery are based predominantly on these four methods. In addition there are, however, a large number of other methods known with which, under certain circumstances, considerable quantitites of tuna-like fishes are captured. Moreover, we must bear in mind that in many parts of the world tuna are caught only for local requirements in mall amounts with primitive gear. This was done alrrtdy long before an industrially-operated larrw-scale fishery with modern catch techniques was intro- duced. An attempt Will be made below to describe the catch methods of the tuna fishery, no matter whether they affect the world production or wbether they are only of local importance.2

- Uegarding the gystematics of the fishing pear employed here compare v. Brandt, 1964. ; A. Hàrpooninm eand.hodtini,'

As is the case with sea'maMmes,- largeHrish are often. - the obJect of an individUal catàh.: -The

is hunted with gear Intended only for the indiVidual eatdh::. - This applies also to-the tuna fipétieà and h4r.P0.91W.Wereo:

still are, used in tuna fisherY. The 'harpobna,.differ rom the spears throur,h the Pt:1dt that:thelrpoint (ortheirpoiints )

becomes separated'from the shaft when it penetratesthe victim. To prevent it and the victim from getting.lostfthe' -- head is cbnnected with the shaft and/or . the harpdorier*b”ti line. The shaft connected with the line actS atthe_ same time also as braking and tiring device. - :-Its:Platie May also he taken by.a bladder. The'float-indicates -:atthe..saMe time the escape route of the harpooned animpl.-

The of Neptune or Foseidon is nOthingelsé P. 20'. but Ulu old tuna spear of the Mediterranean-Sea . (Ehren- buum, l917), whicb today Is rEcognized:eveTywhere. as fisherY- .

s7mbol. The trident was and still is . to some extent Usedl in the tuna fishery,'as well as for caPturing and . dolphins.

The harpoon thrown by hand or by means of 0 mechanical- •

• trowir: ,; device has been used until most recent times also:

In the tuna fishery of modèrn fishery countries. The Nor-

WeitIPS used hand-thrown in their fishery for the

13 -

bluefin:tuna until-aPproximately 1920 (HaMre,-.1963 ).1 . .The Japanese still us the three-pronged harpoOns. On each ohe Of the three polntsiis a-harpoon head,connected . .With a short line. All three lines Cômbine,to:forM the,harpoon line proper.

The harpoon is throw• Whand frcei a. On the.bow Of the vesSel. : Sometimes the platform.haa . rodm for

two ha-rpooners.' On the platform are at timpa support a for .

the feet of the'harPooners ancta Small boX : to hOld-thelarpoon line,

The band -thrown harpoon may be replaced by one propelled by a shot lun. Thus, guns are used for shooting harpoons in fishing for large tuna. In particular the harpoon gun built in (Thiel, 1938) and later in Norway has temporarily found wide distribution. During the late twenties nearly 200 small Norwegian boats used harpoon guns for hunting tuna (Hanson according to Hamre, 1963). The harpoon gun is a 12-Imn1Weniser gun able to shoot an approximately 40-cm-long steel harpoon (actually only harpoon point) with two swing-out barbs (Fig. 1). Attached below the barrel of the harpoon gun is a box for holding the line. The latter, made today from nylon (1/8" and appr. 50 m long)t may unwind also from a line-holder standing in frontof the harpooner, similar to the one used in navig&tion for rescue lines. To the end of the line is tied a thick.er line with a float, as was mentioned nt the beginning, in order to tire the shot tune. Such Abb. 1: Gewehrharpune zurd SchieLen von Roten Thunen

Fi ' . 1: Gun harpoons for shooting bluefin tuna.

"retarders" are known not only in the tuna f:ishery.with P. 204 harpoons; we shall encountcr them ae.ain when discussing tuna fishing with angling gear. - 15 -

The use of the harpOOn gun-from thelpoat requireS,. »asdoes Tish shooting in general, great skill and experience. Not onlithe:refraction Of -the light . in - the-water:;- but . also the behavidur of the tune must betaken Into conSideratlôn._ . . In Norway. gun herpoOns have been . ln use'since the beginning -

of the- thirties.nOt . only_TOr tuna,,.bUtaiSo for dolphins. (Sun1,19,38). ;..

In Germany the harpoon gun was first usedfbr tuna P. 205 fishing on boats leaving from Finkenwerder (Fick 1947/48). At first the end of the line was tied to the cutter. Only

when it was established that the fish tore the harpoon out of its body or that it broke the line when its end was tied to the ship, was this:line, too; tied tà a large. bladder 60 cm in diameter. In thià manner the harpoon Was prevented

from pUlling out of the tuna- and the cutter was able to follow the quickly tiring . fish.'

Along the American Atlantic coast harpooning of tuna from special vessels was, until shortly before the e;econd World War, the main catch method used by the professional fishermen (Norman and Fraser, 1963). After the Second World

War swordfish and tuna shootinir with harpoon guns has, apparently, not been practiced any more aiong the North- Atlantic coast of America (Wilson, 1960).

It must also be mentioned that submarine hunters,' equipped with harpoon guns, are interested in small tuna as catch. HoweVer; Ivanovit , (1954) reMarkaln thlS:COnneCtioh on the occurrence of tunas: ."They seldom, gO to shaliow:WaterS: where the spearfisherman operates":

An attempt May also be made occasionally to shoot • 'tuna from a distance with à shotgun, ad_ia . done of small wha les. Here,•tOo; -great . deManda' are madeon-the: accuracy of the aim of the marksman» . .iProm the Danish fishery It is reported that tunascaught with a line have been killed by shooting (Thiel, 1938), in order to avoid a long struggle of the fish hanging on the fi11 hook (in this case bluefin tuna) and especially a possible break of the line.

B. Catch after iturefying

It was impossible to find out whether a so-called fishinr with poison for tuna-like fish is being pract•ced. This is likely connected primarily with the fact that the use of plant poison is a spcialty of the inland fishery (not only of the tropical). Only relatively seldom are p. 206 poisonous baits usfd also in the sea fishery to make fish r'se to the surface of the water by stupefying them and then to catch them without the aid of any othfr gear.

What was .said of chemical stupefying agents must also be said of the mechanical ones. Theoretically, dynamite and other explosive substances are involved. While fishing with dynamite has been prohibited;:in NOrway Since . 1911

bus, nevertheless, been dineussed'for a long time Whether itS uSe should not be peretted esPeeallY for tuna fishing . DeurS, .194Y).

. . : On:the other hand ., an 'electrical stupe-rying:Of tuna,:: .. — 'caught already:by:.other means-,:has been tried; this will Ie I. -. ' .disCUSsed in connedtibb Mith:the iinefi•hery. -,-

C. Line Fishery with Hook

A considerable share of the world yield of tuna results from line fishery in various forms, especially in the tropical regions. Hand, trolling • and drift l ins with

individual hooks as •well as longlines with a multiplicity of hooks are being used.

We shall disregard here the fishing lines uned by sport fishermen (Taylor, no date), in spite of the fact that interesting experiments have been made in this respect, even with ichthyosauri (see beJow). The same applies to simple hand lines which consist of a line, a lead, a leader and a hook. They are used in popular fisheries in different parts of the world and permit also a fishing et greater depths. :In the >trait of kessind\b?uefin ttna fising is carfied on with hand liner up to depths of 50 to 80 m. (Tiews, 19t.52). 1. Pole-and-line fishing with-liVelbait

Pole-and-iine fishing from a drifting cirSlOW1Y- propelled boat is likely the most Midespread"ffiethod of tuna angling. As exolusiVe day fishery it is knoWn in-manY:parts of the world and differa only little 'in. ita technique. no Matter whether it is uaed by Mahe/brae/1 in Oceania*Thdà nesia or the Azores, or whether it is operated.ona . large:-

scale EIP methdd of an induatrial fishery in. Japan'Or. In California.

Pole-and-line fishing'isused for oa.tohing Sürfaoe, tuna, primarily bonitos and young forms of.Other:tunaspeoïea; Only occasionally are larger tuna . caught mfth Approximately.one third-of the catch Of longfin tlina in America, the main portion of the Japanese longfin tuna . fiahery. and, until recently, 80% of the tuna -caught On the part. of_. the Americans in tropical regions are thé result: of pole-and-line fishing with live bait (Howard, 1962).. For the skipjack tuna this fishing methOd is-regarded as the . most important one.

A prerequisite for this fishery is the availability of live bait (usually sardine-like fishes) in order to lute the tuna, if need be, out of the depth, and to hold it near the vessel during the fishing. For this purpose live bait is continuously thrown out. This scattering of live bait, 19

des1gnnted aq "churning", is regarded us essential for the success of the catch. Often the chumer -- the crew member scatterinre the bait -- occupies a special position among the crew, since it depends on hi s experience whether the school of fish can be kept long enough near the boat and whether the bait is correctly distributed. Occasionally two persons are employed to scatter the bait-fish, one person at the bow and one nt the stern (Cleaver and Shimade, 1950).

. To increase'the effect, Water:is frequently sprayed. - from the .- fishing boat onto the :surface of the Water. Tft . small boats . this_is done simply by spraying water - with a . shoVel-like device or the oar..-On modern vessels special ' spraying devices are inStalled which were developed by the. The spraying of the Water is supposed to imitate Japanese. . . the noise of jumping bait-fie and alsà to hide the shadow: ' of vessel and fishermen from the fish that are to be caught. It is'not always possible - to keep the school for an y length of time near the boat. In spite of_this the opinion prevails that spraying installations could possibly contribute to • increasinl the yield of the tuna fishery . by. pole-and- . P. 208 line fishing with live bait.

The procurement of live bait and its storage requires :r,uch work and gr(at outlays. -ometimes the catch of bait-fish encounters difficulties since they are not always found in - 2

suffiCient quantitiea. Th1 8 is the reason:Wi&this -catCh method cannot be employed everywhere and in every . Season •• of the year, even though:the tuna :oégurrencea'arefavOUrabla Attempts have therefore been Made' to r $ardine- • like fishes also other - Species that.may:be cilueltr:r:fbré readily and nt any time, such as Tiiapià and-the/j1mericah: - •

shad (da Fonseca, 1962). Bait:fie are reqUiredalSo to provide the fishing hooks with live:fiah- Butthia:isn'ot ( • . • always necesaary. 'Frequently thé hooks feathers or so-called jigs; we shall'OoMe - back to:theM- . when di!icussing the trolling line, - In every : case the':.hoôk, no matter whether with or without bait'-L-ls to: be_held.So that it.dances lust above the'sUrfageHôfotheHnSteri . ,whiW., the are thrown out.

The itself consist of a bamboo of varying length and of a fishing line with the hook (tg. 2). The rod may have a length of 2'- 3, but also of 4, 5, 10 and more meters. Sine the baiting and the reloval of the hooked fish must be done quickly, the hooks are usually without barbs. Sometimes the latter is filed off before using. The hooks vary grer:tly with respect to their size, depending on the tuna that are to be caught.

The bamboô rod is frequently covered livith string or with wire to strengthen thé rod and to i)revent the loss of the catch if the rod should break. At thé tin of the ' Abb. 2: Thunanel mit einei;1 und. zwei.Soken

Fig. 2. Tuna fish line with one and two fishing rods.

rod is an eye made of stronger string material, to which the fising line is attached. The construction of the line

varies in the different fishing regions: it is made of fibres with a wire-lender or entirely out of wire or possibly also

of monofile polyamide (Fig. 3). wwaeratéde ee.ww...d.d.W.a malel,aWaa m.tabwfà...... .

.1/)

•

pqi.,

Abb. 3: Leinen für Stookangein in der,Thunfi'EJoherei--

1.Kalifornien 2Madeira , 3,Kap V e rden

Fig. 3. Lines for pole-and-line fishing in the tuna fishery. 1. California E. Madeira 3. Cape Verde.

To get a better hold. on the eingling gear alcind of .

quiver, made of leather, tire rubber, linen, or soMe other material, may be wrapped around the body of the in the lower end of this quiver the fishing rod finds a hold. , . . ••

TheSe devices are siMilarto-those used also. by the sports .P.i:21:0: :fisherman when,catching large-sea-fish with fishing rods, the so-called "rod rests":. • The number of angling fishermen varies according to the size of the vessel. There may be only a few, but there also may be 30 crew MeMbers or more. When catching heavy

tune two or three fishing rods may be attached to one hoolz - (Wir. 2). nooks have even been used that were supported by • 4 or 5 rods (Godsil, 193B). In that case the fishing lines of the individual rods are twisted together on a common ring from which hangs -- also twisted together -- the leader with the hook. The handling of a •double or even multiple fishing •line requires an exact working together of the fishermen. Two fishermen operating one hook are easily in a position t haul tuna up to 30 kg onto the deck.

rlenerally, the fish is pulled onto deck by swining the fishing rod high. rance there are no barbs on the hooks, t1)(- firb frees itself from the hook when hitting the ground. 9ma11er tuna are swung out of the water in such a manner that they are caught end held ti-,Int by the upper left arm of

the fishermen and conveniently taken off the hook. To save

clothes, a kind of protective vest with left sleeve, i-de of lines', is sometimes worn (Ritzhaupt, 1963). When using this

technique th( fighing Une is usually just as long, or only

a litile shortcr, than the respective rod. French tuna anlers- can . pUll up'the fishing : rOd, or..the'hObkedYtlina, over A roller. For this purp6se linesare apanned betWeen

the masts.to which are suspended blodks'with:aline J cd over them. Attached to one end -of • suMe is the-tiP

fishing rod which iS held by end. held by a second man Standing behind theaneer fish snaps the hook even larger tuna - can beJlaUled without danger that thè 'rod Will break.

In the local fisheries on the West-African coast and the islands extending in front of it it is customary not to pull large tunas with a swiuging motion of the fishing

rod -- which here consists of a palm-leaf rib -- onto the deck, but raiher to pull the hooked fish in the water to the boat with the downward-pointing tip of the fishing rod (illustration in nrandt and Steinberg, 1964). • It 18 then hooked with a pole-hook, pulled up and stunned with blows P. 211 of a club. If usrd thus. the fishing line can • be much

shorter, not much more than 50 cm long.

American tuna clippers are regarded as typical vessels

of this fishery with fishing pole and live bait. They have butlt-in bait tanks through which fresh seawater is c on- tinuouly pumped. •In smaller vessels hait containers are placed on deck and connected to a water pump to have the water circulate through the container. The first types

or vessels of the tuna fishery with pole-and-line fishing have- built-in bin-like contalners which are connected with the outside water. But the flow-through of the water frequently does not suffice with this form of storage to

• keep the bait alive (Ritzhaupt, 1963). For this reuson even the smallest boats are now equipped with water puMps.

The bait fish muSt not be kept in darkness. There exists then the danger that the fish will knock themselves to pieces_on_the walls. In light the bait fish are optically kept together in a school which whirls around in the bait - tank. 'The containers. aré.therefolieilluminated on • he-2inside - and Iñmai1y cases Painted white or they have,.in«the . case: of-the'transportable forM'uSed on small boats, glasS:Windows

- through which the bait . fish,can be observed and through which. they receive light, in so far as the container:is hot Open' at the top.

There must be sufficient place on these vessels for the angler for fishing with live bait. For this reason modern angling boats ofterLhaVe the wheelhouse set forward to obtain a roomy platform on the after body of the boat.' Modern tuna clippers have recesses in the railing Where the anglers stand, or they have racks suspended on the outside or the board wall, just above the water, for a standing place. A speCial podium for the angler may also .be attached to the stern of the boat on the outside. Thé bait fish are .captlired . ,in.speolal WOrking' operations, in some cases by special boata at" Places near the shore. Used for this . purPose are'surrounding'neta (purse seines, lampara nets) or dip'sneta:Of VariOlia : ShaPea,, but also small beach seines. The latter areharder-:on fish and as a resUlt feWer remain alive. . The . bait'fi:ah» are collected in net-containers or in'floating soMe oases boat-ahaped, container .boxes. - -In-manY:Cesea theaé containers conaist of plaited baskets-which.flOàt'in thé- water. If the catch is .carried out oarefùlly'andwith careful treatMent the bait fish may be kept alive,in- thes • containers for several days, even weeks:(van Camp Sea Food• - company, no year given). From:here they are tranéfeD6d as required, before leaVing for the. tUna fishery'to.the -tanks of the fishing vessels.

2. Troll line fishing (Trolling .)

When fishing with pole-and-line the boats are usually slowly rowed or driven forward. This is in effect a transition to troll line fishing. In their typical form the trolling lines are pulled behind fast-moving row, sailing, or motor boats, ùsually in larger numbers, close to or on the surface of the water. This is a catch technique that has been practiced from times immemorial in the tuna fishery, especially in the vicinity of the coast. The hooks ubed . fOrtrolling . may. .be . of.the . 'mbst

varied shapeS. They May be combined With artificial bait

or Provided with natural:bait. RénOwned'.is the.bonito nehery in Oceania mith artistically Composed hookS (Hornell

1)50). The latter cons19ti6f . a. Shanmade ..Of Mussel Shell,

or bone with .a.tied7.on . tip Made -of tortoise 'shell,. bone'ür '

mussel Shell (lately alSO The -hbek- in - thiS: -

form is at the same tiMe: .alsO a lUnker which 1S : SUPPOsed.to- ..- make_the-fish snap at it. ThehOok is:guidred. - With a fishing

rocl in suCh afmannerthat lt:juMpslust aboVe f .therface Of

the water. Bait : fish are not used, but for the:reasonS

mentioned abbve water frequently splashed with a small oar.

Related to the• tuna fishery in Oceania is the renowned kite fishery. A kite, made of leaves and fortified with palm ribs, is pulled behind boat which is slowly rowed

against the wind. Suspended from the kite is a long tail nt the end of which hangs a ball of cObweb or of cleansing cotton or a . piece of shark skin as bait. The bait is also

.supposed. to dance on.the surface of the water and.'thus- .induce the fish to snap at it. Even today Such kites mude of sown- P. .213 together pandanus leaves or paper in bamboo frames are still .beinp; used. The kites may be quite lare,'Spproximately 1 m and 30 om wide. The lino to tnke the kite into the

nir [any be 100 metres long. The tail-line runs to n metres.

Pishing is operated.from small boats with a crew of two. One man keeps the boat up; against the Wind.,*Or if the wind 13 too citron th ri athWart It ; the other man handles the kite:. cOntinuonsly pulline5; the line he fritot keep tiié hait etuSt By - above the Surfac e . of the Water. Onde thé fish haieen caucht, the kite must be hauled in, the catch removed and the kite prepared for another flight (Arnell, 1955; v. Brandt,

It is of interest to note that today sports fishermen also attempt sometimes to use the kite in tuna fishing, even in fishing for our bluefin tuna. In the Oresund, for instance, during the annùal Danish tuna fishing competition of 194? an effort was Made to fish with box kites (Svendsen, 1949). However, this catch method has not taken root jri other .Parts of the wdrld:

The Oceanic tuna fishery with trolling lines was encountered already by the discoverers of the South Sea as uhuracteristic fishery. Not quite as old is another well- known trolling-line tuna fishery (albacore) which is being practiced by the French people in the Bay of Biscay. This fishery is supposed to have been developed just prior to the ber,:inning of this century by fishermen from La Rochelle and Sables d'Olorme.

In the Bay of Biscay the pulling waS originally dbné . by sail boats. Theàe So-called "Thouniers" .can,pull up tb 28 lines'(IÎ. Brandt, 1956). :They are'faatened td the —stern of the boat and to to large. m . lOng hinged mast-a - -(tangars) whioh sw±n out aideWays apprdXimately 45 ° and 5). The lengthdf the:Ilna varies LongeSt.are*the 4 lines fastened to the outermOst end : of. the hinged7:treeS

-they are approximately 40 fathoms ldng. The - innelandrtest, .linés • are about 6 8 fathomà long. The line ends ina

Abbe 4: Schleppangelboot (Aufsicht)

Fig. 4. Trolling boat (top view) . Abb. Leineefilb.rune

- Fie,. 5: Arrangeffient Of Ilnes:.on'a Frendh-,tUnatr011er:

leader made of strong material, of wire or monofile polyamide of great strength. To minimize the jerk when the tuna Snaps the bait an at least 30 cm long rubber piece is frequently inserted as shock absorber between line and leader. 5hock absorbers are needed already because of the high speed (5 - 7 knots) of travelling. As the speed Increases aboVe G knots, the share of the captured tunas increases in relation to other fish. Of the Pacific black skipjaok it is reported P.215 that -"they wIll take•any hire trolled 'at-any ,sPeed tipto

8 Or 10 Miles an hour" (ROSa, 19.(;5). •

- The hooks used in•trolling:With "Thouniers" are . .seldOM baited With live. bait "tTeually artificiel bait iS tised The hooks May be-double Iboks covered with corn straW,

featherS Or strips of- Material {Fig. 6).1 -We11-4noWn in tuna trolling are plastic baits which are supposed to imitate cuttlefish. Finally, for trolling are used also hooks deqicnated as "jigs" which were also mentioned in connection with the pole-and-line fishery (Fig. 2). A j fg consists of ia heavy metal head, frequently provided with a glass eye; lodged in the metal head is a hook the shank of which is imbedded in a tuft of feathers. The feathers are usually white and at their base protected with fish skin. The jig is fastened to a loop on the head. The hooks may have barbs, but they may al'io be barbless.

Most of the hand-line fishermen mentioned in the preceding section, as well as the longline fishermen still to beidiscussed,take trolling lines along when going to or from the fishing area. These fishing lines are at the same time regarded as scanners to determine any possible tuna (-rurrenoes , ..•.•.., .

Fi17. 6. Tuna hookà for • trolling lines 1. California 2. Bretimme 3. Portual 4 and 5 Japan

Abb. 6: Thunhaken fUr SchleDpaneir.

I,Kalifornien 20Betraù;ne 3.PortuS.al . • ,,u.5. Japan According to Nakamura (1954), characteristic drift lines were used in the old japanese albacore fishery. These consisted of a small barrel as float, around which was wrapped a fishing line. The hooks were baited with sardines or cuttlefish. To keep the hook suspended at the right depth and to prevent the, : line fromunr011ing 2 itseif, thelatter . a °Ord, The fastening had:to 'be —was fastened« by meanS Of On •the one.hand,-strônil., enough so.tIat itwould not:break when the tuna snapped the bait, thus causing the hook to penetrate quite deep, and, on the othcr hand, it was supposed to break as soon as the hooked tuna tried to escape into the depth. After that the line rolled off the floating barrel P. 217 which began to whir1"like a mill-wheel". This indicated to the waiting fisherman that a fish had snapped at the bait and he began to haul in the line, just like a sports angler ' reels in his line. Eight lines were set in one row at

certain intervals. 3ome people believe that in this old

form of the drift line we can perceive the origin of the long_,line to be described in the next section. The latter is supposed to have originated when the floating barrels were connected with one another by a line.

The tuna fishing lines which are used by the German coastal fishery in the North -3ea for catching bluefin tuna are typical drift lines. Here 5 to 6 lines are laid out by the drifting cutter. •To'be.suré ..,....thia,INSO

after the presence Of tuna hadactually tieat deterMined', perhaps by means of sonic depth finders - (Tlews,Y196?)* Thé: individual . fishing line consista of ..à 10 m-itifie - ader,ma4': of steel wire 1.8 mm in diameter-,150 P. érlon:rOpe attached to it are aPproiimately:220 . M bf.Wht+manila - rOpe -; 10 mm. A small float ià attachadbetween thel5erloitandH the Manila rope. It ia,éuppOSéd:tocontrolthe::-poaition of the line rather than - torbrake'theflah• , ; • c ' The •inéracriaïns. tightly connected to the boat. Thé large bladderilsed: previously, as in the harpbon-fishery, for:tiringtunaohaa

• come in disuse again lately,

The tuna are allured with fresh herring, ol4whitings. These are also used to bait the hooks. For catching bluefin tuna in the North Sea Japanese longline hooks are used. The latter are supposed to be better suited

since they can be readily accommodated in the bait and after the fish has snapped the hook it does not as easily unhook in the mouth of the fish.

Electrical killing devices have been proposed in connection with line fishing (v. Deurs et al, 1947; Meyer- Waarden, 1951; Nagai, 1955). The idea behind it is to at

least stun the tuna electrically after the fish has been caught and thus prevent it from fighting • and possibly breaking the'linei The electrically stunned tUnabanfimMediately . •be pulled °lase, • killed and hauled.on - board.

• Three.fishing lines Can - be attached simültaneoUsly . . to the eâctriCal fishing gear deVéloped éSpecially far the":.

- profesSionel fiahery.: -.Bachline is appraximatelY : 50.M long

.ondconaibts_ _ ofopper:wire_ „_ braided by steel. • . • a tensile strength of 500 kg. Attached to it is a leader, made of insulated steel wire, bearing the hook. It ha s breaking strength of approximately 250 kg. The fishing line is connected with the electric device on boardWhich2 consists of the transformer, the impulse transmitter, and the so- called hook-box with three line connections. The required current in Obtained from the ship's power system or from batteries.

If a tuna is caught it tries to swim away, thereby exerting a pull on the line. This pull automatically activates the impulse transmitter through the hook-box set up on board. The current flows through the fishing line and the hook, which acts as anode, through the fish and through the water back again to the ship or the propeller of the ship (cathode). The fish receives an electrical blow of approximately several hundred amperes; this stuns it to such an extent that it can be taken on board and killed. As the pull on the hook-box slackens, the impulse transmitter is again automatically disconnected. Should the fish regain Consciousness before it is haulEid on board, the impulse • transmitter is activated agnin by therene*éd - Plgro“he::, - fleeing fish Or lt can be oonneâtad Manun4yhy' :theiShermah :

4 ._Lon£11nee

Disregarding Individual déepeachinghand:.1ines - the above-mentioned,pole-and-line .;:trOli lIne . and drift

line permit only a:fishing for tuna'Whidh live in the surface water. With longlines, however, deeperlying . ; 200 m and over -- tuna stock s Can be• fished. ESpeCiallY": the larger, much-desired yellowfin tu na live at greater depths und cnnnot, in contrast to the younger specimens, be reached with surface lines. These larger tuna are usually located near the interface. Longlines are therefore used in particular in tropical regions withY a deeper interface.

Reportedly the tuna loni;line was developed by P. 219 the Japanese more than 250 years ago. The present-dny prefecture of Wakayama, southeast of Nara on the peninsula Kii, is regarded as home of this longline fishery. Nakamura (1954) gives a detailed description how this fishery developed from a small fishery with but a few Pish hooks in the vicinity of the coast within a rathrr short time to the present-day vwrl i-wide large scale fishery. Especially the change from the smiling and row bouts to boats with combustion engines, which tôok i5lade bet'Ween 19, 0 3 and 190 6'; gave fisfiery With longlines a gr t. impetua.

ilbwever, lOnglines are Used nOt:only:td Catchstùnn,

but also tO datch . variOùs' Other pélagic large ±-1..sheé;' such as swordfiSh; sallflahsharks, .etc: TheeConoMic of this fre4uently'considerahle sécohdarY catch mny. be of decieve importance for the ,profitableness . of.this form of tuna fishery.: ÉxaMPles :haVe been published 1;vhere.; in addition to - 25 tnnas;: 225 .Sharks were alsO captureà Ivoreov,er, efore being hauled on bokird large -pleces'are: seetimes torn out of the hooked tunas at the last,moment by the sharks. In one nase Of - 169 . tunas'66 had-been damaged by sharks (McCornick _ .

The tuna lon7line is a fishing device from the main line of which a varying, but usually only small, number of thinner lines branches off in a customary manner from eanh section. At the beginning and the end of each section the line i8 suspended on buoys. The depth of this catching device is regulated by the distance of the buoys from one another when set out and by the length of the buoy lines.

To be exact, the typical form of the tuna longline represents a drift line which -- and this is unusual in the sea fishery is driftingfree from the vessel, even though under constant observation during the day and with lumps during the night. • I f t 'Una lOngIiiieS are deSbribe&„ , . large fishing c,ear, .SUch as arebein•USed• the "distant fishery"In.thé-PacIfIctWIndian0Cean:,... _ . . . and in the Atlantic e 'it-mitst nOt.116e:fOrgOtten thattheSedeieS1

0 back td dr1fting:Smal171ong1ine9SUCh .àrj:are'• Still .beingH used in the Far America (o f . Chen and Wu, 1955, P ..C. Wilson, 1960 • Atlantic coaF.It of North America the lonelines for the bluefin tuna are, to be sure, anchored;.:they,iireH.thlisHnOtA.rift • lines any more, but rather set

The main line ,of the Japanese tuna longlines wes, composed of several sections (Fig. Y, according to Kurashiki Rayon Co.). Each section is divided into several, usuallY equally long,sub-sections from the connecting places which branches off in each case one mouth line. The length of one section of the main line between the buoys amounts to from 150 to over 400 m, usually 300 m. Previously the main line was made of hemp, then of cotton, and today of synthetic fibres (usually PVA). The strength of the line was increased in the course of time. The number of sections connected to form a main line varies considerably, More than 400 sections of a line may be set out together (see below).

The buoys which hold up the • line consist of :a bamboo' pole with a'flag, to the weighted lower end of which'ib . • . attached the buoyline as well as a float (las sphère of *.) ,cm in diameter with net profection 'or rubber ballooni , previously also wood.and metal.flOata),' After . every. 20 2b :sections a lamp may - be placed inStead of the flag pole. Previously such larreiwas opèrated.with . carbide, nOw'. . with batteries. It fadilitatès . the. hauling in of the line • during the . night hours: SometiMes radar reflectoraYOr . small transmitters are also'used tO - findfthe'lina, espeoiallY after a break in the . Iine. .1)epénding on the desiree -dePth

the length of the buoy llne'.amounts to from.4 .

• The number and length of the branch lines per line section varies in relation to the kind of line. Line - sections with 12tranch lines have been known, but also such with only a single, but especially long one. The latter is used for the yellowfin tuna. For spearfisheF and many shorttwanch lines are required. This often defends on the personal opinion of the fisherman (Nakamura, 1954).

For the branch lines it is essential that they, just like the main lines, become stronger and longer With a progre-sive development. Generally, the branch lines of the tune longline are composed of three parts: the branch line proper, made of fibre material, a connecting piece, P. 222 added only later (Sekiyama) and made of wire, possibly

- P. 41 - 0 / - 4 . • , . • .. .. • . . • • • • - ' . . . .

■ - /I T • • • .. 1- . '. P. . . ..

. .

5

7: Schematischo Darstilug einer : Thuniangleine loGlaskdgel, 2Ve1bindung zur BojenIcineVerbin- dung zur Mundschnur, 4,Wirbel in der Hakenschnur,

- 50Verbin1ung zum Vorfach, 6 e liaken.

Fi-r. : nchematic re pre sentati on of a tuna . longline 1. gin :35; sphere , 2. conne otion with the buoy line , connection with the branch line , 4. whir l in the hook-line • h connect ion with the leader, u. hook.„ 'covered with fibre cord . (previously hemp.covered mith cotton) and the actual leader .(TsuriMoto) made of wire with

.the hook. The.lengths'of.these three'parts vary. FOr'a •

Japanese longliter. of,I500 BRT , operating'in . theHOentral,and .S'outhern Atlantic, the • following. meaarements are-reported ,

per line section and branch,line,(kurashiki RaYbn

Lene,4 per line Section: mi (5x60= 300 m) Length of branch line 11,5 m- (15 m)

.Length of ConnectiOn m (75 - 8.0 mr , line 1_,enrt.th of leader 2,0 m (2.5 - 2.7m)

(The numbers. in parepte8èé refer to .data reported by Salto, 1960.) „ .

Line sectiOns with very many :hooks . (11 .-. 12), with-

hook - lines of varYing lengths (e.g. tWO 0-m-hook'lines , one 9-m line) are recommended.alSo fOr'the alternate with

bluefin tuna. The lengths of the line sectiOns amount . here, for instance, to '225 m, the lengths of the buby llnesto 15 - 22.5 m. •

.. For the yelldwfin tuna line sections of 150 m with- only a single hook line of 37.5 4 15 4 m for the parts mentioned above are - recommended; buoy lines of 3.8 - 4.4 m (all data according to Saito, 1960). . Usually each eeCtion Of theline.ià by itself in e basket Or a Metal tub. .The hoOks. out on thé . edge of the container:. Sinde-the baskets take . . up a lot of space they:are soMetiMes diapensed:withand one or two sections of line are.packed in a*triangular or square: piece of linen Or webbing: Undércértain . dircUmàtanées, _ . . however, the branch lines with:the hooks: are first-linhOolted and then stored seperately,::(see may carry as Many as 350 - - 450 baskets. By taking-:alông smaller catch-boats . in à-"pickabackn-sYstem4uP tO:,6 veseel-S, _ of 20 BRT and a length of le) m) or bYbeing. .aeeoMPahied- bY: other feeder boat s of:which' eaeh one -can'alSO'aervide:up to 300 baskets, the catchpôtential of 4 Single ttina liner can be greatly inoreased..,

As a matter of fact, because of the time required P. 223 for settingland hauling in the lines, 400 baskets per vessel are usually regarded as maximum (Takayama, 1962). At any rate, 400 baskets holding a length of 400 m each represent a total length of 160 km per longline that must be set and hauled in. .1ince the line hangs down garland-like, the actual distance between the beenning and the end of the line et sea amounts to approximately 50 - 60% of the actual length of the line. To what extant it in possible to increase the number of hooks and the length of the line -- and with it also the chances of success -- depends to a large degree on .th'e swiftneàS and the StbMina of the' shlp's crew. The work,IS regarded as tough. "WorLiniin thts frbm before dawn to Midnight with almoSt nO tiMe to rest,..Living '

In a srulll boat with no.coMforts.or..recreation, - and repeâting.. the saMeoPeration'20 or 30 times, the exertions of the men • employed in this fiShery are:by-no means coMmonplapeNakaMura,. . -

].9 4) •

A published example of a Japanese 560 BRT longliner (Kurashiki Rayon Co.) estimates for thE setting, beginning between and 6 a.m. on an average 92 sections of line, each with 4 hooks, per hour.. -lince there are 400 sections of line with 2000 hooks the setting would thus require appr. 4iL7 hours. After the setting the ship steams back to the start of the line. From this side begins the hauling.

Forierly, when the lines still were shorter, the vessel steamed up and down the lines and immedibtely took out the fish.

Today with the very long lines there is no time for this any more. At about 2 p.m. begins the hauling when approxi- mately 40 sections of the line are hauled per hour. 'Thus,- the hauling extends over the entire afternoon into the night, under certain circumstances for more than 10 hours. 4hile only a portion of the crew is required for setting the lines, during the many hours of hauliri.g the cr(w has to be changed off. Koreover, the crew takes turns working the individual shifts in setting a well as hauling, so that the individual •

fisherman on, after WOrking'shifterreeiring . .qulickMOVeMenta',. carry out Work Which Is ]es d orna nding . YerY..freqUentlY the working periods are 'still longer . than'mehtigiàï'd'àIoé cially when numerbus hoOkS,haVe : caughtfiàh of 12 hdura are no rarity. .Then,e, eribrfriuSd0',mandmade:o the indiVidUal creWmeMber PreSént agreat':prd,bléMin .-/the: longline fiShery. ..i/Ureduction in the riUMberbehObkn and thus of the length ofithe'line:and workingperioa is not possible Since : the pernentageatCh low. In the Atlantic a catch ,of3%,i. _-a.rekoned _ only 3 tune are caught with every 100 . hOokS, necessary to set. approXimatély 2000 hbevenas:mane , 2400 hooks have been in order.tb make thefiShery as set . . , profitable. But this . requires great bbdilY exértiOns . bh the part of members, onl y on the creW and that - days, but during many weeks and monthWunder:tropiOatCOn7; ditions.

These circumstances may have contributed to the fact that, dinregarding the above-mentioned smaller fisheries on the \• est Coast of North America and isolated experiments of varlous research institutions, a long]ine fishery is so far being successfully carried out only by Japanese and by r,siatic fishermen trained by the latter (especially Koreans und Formosans) in the Atlantic, as well as in the Pacific and the Indian Ocean. - 45 -

Only few deck installations are required fur the

handling of the tuna longlines. For the longlines mentoned

here a line-hauler is required with the aid of which the lines are hauled and coiled up. The line-haulers, introduced in 1911 by the English, are today generally of Japanese orIgin (Izui Iron Works Co. Ltd., 1959) and are used in

different sizes hydraulically or by means of an engine. Hauling speeds of 120 • to240 m per minute are reached. Without the use of line-hauling machines it would be impossible - to haul in the many kilometer-long lines. Further, a three- unit pulley is needed on the railing to divert the lines;

also a table or a chute for the prepatation of the lines for setting or for coiling during the hauling. As auxiliary gear drag anchors for pulling the lines closer or for searching for their parts after line-breaks, as well as

various gaffs, spears or harpoons for landing the fish are needed.

For a better understanding of the handling of the longlines during the setting and hauling we are bringing

here the free translation of a description according to a prospectus of the Firm Kurashiki Rayon Co. Fig. 8 shows the after body of n Japanese tuna catcher with the position

of the crew Mo. 1 - 14 occupied during the setting of the line. - 46 '-

No. 1 pushen the sections of the line broulht from • P. 225 the storehouse onto a chute-board. No. 2 joins the indivi- dual sections together to a continuous lino. No. 3 hands the ends of the buoy lines to No 6 and pushes the lines on to No 4 and 6. In the meantime No. 6 ties the buoy lines to the bamboo poles with glass spheres and flag which No 7 has prepared for him. No. 5 puts the bait on the hooks. The line is now ready for castim, . No. 4 watches the main line, No. 3 secs that the buoy lines run off free of the main line. NO. 5 takes care that the hook lines do not tangle neither with one another nor with the main line and that thevare cast rectangularly to the course of the vessel. . , - H• , No. 6 throws out the buoy With the flag-pole "after .the . respective section of the main line has been set. Other men assist him. No. 8 prepares the bait for No. 5 by unpacking It from the ice and putting it down so that it will be handy for no.5. Mo. 9 pushes the lines to Nu. 1 so that the work will not be interrupted. No. 12 takes care that after

20 - 25 sections of line a lamp with battery is set instead of the flag-pole, No. 7 assists No. 10 and 11 to take the rias s spheres and the bamboo poles out of their storage ' places. No. 13 is respônsible,for the speed of the machine and No. 14 watches the course of their, as well as that of other vesselb during the setting. •

The lamps are not only suprosed to facilitate the observation and . hauling of lines in darkness. With their , . - 4' -

aid the line-ohanging currents can be observed during the niet and broken linen may possibly be found. Moreover,: , 'eaoh lamp is the signal for orew members No 4 - 11 to chane off in their work during the setting. Thus, e.g., . No. 7 takes the place of No. 6, the' latter the plac e of No. 4, etc. 3-2-1-5-8-12-0-10-l1,thelatter'takes• the place of No. Y.'

The end of the line is.merked b r a special flag. The

boat drifts in the nelo‘hbonrhood while the crew is Sleeping.. _ In the.meantime the line-hauling machine is being prepared • for the hauling operation. .

The hauling takes place from the fore-deck as shown

in Fig. 8. No. 1 is responsible for tile speed of the hauling

-machine. By the tone of the machine and by the tension of

the line he must be able to tell whether there is a fish P. 226

on the upproachinp hook-line. Ile must regulate the speed of the hauling machine accordin7lm takinc, into consideration

ulro whether the finh i dead or alive. In bud wcather the

ne mt r break if hauled too'falt. This must also be pre- vented by No. 1 who must at the saine time );ive the necessary

instructions regardinp., the speed and the course of the ship

to the skipper of the ship. The haulim; machine coiln up the line under the supervision of No. 2 who hands the indivi- . dual sections to 'Plo. 3. The latter transmits them to No. 4 - 48—

Who tles each section together with previously prepared short pieces of rope and passes them un for storage. No. grubs the hook lines that did not catch any fish and hands

thcm to No. 7 who, in turn, coils them up to rings of appr.

30 cm in diameter. lie gives them to No. b who at the •same

time helps No. 3 to coil up the main line. No. 6 also takes

thr flagpoles with the buoys and the buoy lines out of the water. The buoy lines are coiled up by No. 8, assisted by

No. V, who passes them on to No. b; the latter detaches

the lines from the main line. No. 9 unties the glass spheres

from the buoy lines and hands them over to store. No. 10 detaches the bamboo poles from the buoy lines and hands them also over to store. If there are fishes hanging on the hook lines they are taken care of by No. 11 and No. 12 while

standing on the gangway. They are assisted by No. 13 and 14 who haul the fish with gaffs onto the deck. Tuna are usually

dead and can easily be loosened from the hook. 3harKs usually have the hook swallowed deeper and are hauled alive on deck. They must first be killed before the hook can be cut out of them. Just as during the setting, the crew

changes off also during the hauling. No. 4 takes the place

of No. 14 and so on: 14-13-12-11-10-9-8-7-6-5-2-3 to 4, who

takes the place of 14. In addition to these men, others arc occupied in taking over the captured fish, Slaughtering them, and preparing them for freezing. - 4 9 -

Abb. 8:-.Aufstellung der Mannschaft auf einem groBen . japanischen Langleiner a) beim Aussetzen b) beim Holen (Nach einem Prospekt der Kurashiki Rayon Co.)

Fie. 8: 3tationing the crew members on a large Japanese lonuliner a) while setting lines b) while hauling in lines (after a prospectus of the Kurashiki Rayon Co.)

Fie. 9 is a further example from Japanese literature

(3alt°, 1960); the description is similar to that for Fig. 8. Gince Fig. 9 concerns a smaller vessel we shall describe here the activity of the individual crew members. - 50 -

Fig. 9 shows thr No. 1 baits the hook and cants the hook-line. No. 2 takes care of the mE4n line, controls the speed of setting and must, thus, work hand in hand with Mo. 1. No. 3 clears the buoy lines and hands p. 22$ them to No. 5. No. 3 must also help No. 1 and No. 2. No. 4 joins the individual sections of the main line together und passes them to No. 3. No. 5 receives the buoy line • from No. 3 and fastens it to a loop on the bamboo flagpole. • No. 6 ties the float (here glass sphere) to the bamboo pole. No 7 hands the bait to No 1 and opens the cords that keep the balls of the individual lines together. No. fetches the sections of the lines and gives them to No. 4.

The hauling in isshown in Fig. - 9b.- No.- -l•has the command on deck, regulates the • speed of the line+coiling,. machine and keeps contact with the bridge. No, .2-lookS after the proper coiling- up of the main line - by thé line hauling machine and passes the hook-iines-(provided rio. fish hang on the hook) from No, 5 to No; 3.. No; 3. takes over the coiled up sections of the line'from No. 2'in the pertinent basket ) ties up the basket and carries it away. No. 4 takes the hook-lines from the three-unit pulley On tbe railing and hands them to No. 5. No. 5 takes the hook- lines and rives them to No. 2. No. 6 takes the.bUoy lines. from No. 7 and No. 8 and gives them to No. 3. No. 7 and No. 8 haul the buoy lines with bamboo pole arid floats, give - 51.-

u • me YU MO 1.10.11,11MY4e11.11»0

Abb. Aufstellung der Mannschaft eines kleinen japanischen Langleiners arbeim Aussetzen . b) beim Melon (Saitoi 1960)

Fig. Stationing the crew member s. on —a small Japanese longliner

a) while setting lines b) while hauling in lines (;aito, 1960)

them to No. 6, take off flot and flagpole and take them away. No. 9 pulls in any captured tuna with a long gaff. No. 10 and sOme helpers haul the captured sharks on board, remove the respective lines, slaughter the fish, wash the deck, etc. . • In'conclusion.we shall dencribe the handlirig tuna Iblaglines oh renearch ships, :PirSt description of the use of tune .›ptlihes on sthe.American research ship "Delaware" according toSteinberg.(1 Here unfavourable space conditiôhs . must'be - taken intà : pon- sideration-(Pig.. 10).

The netting of the lines takes place as follows lq,a)

"No. 1 holds the tub with the section of the line which is just to be set on the railing or on a bench built near the railing. It i8 his responsibility to see that the main line runs out clearly. He also casts the indivi- dual hook-lines with the baited hooks in such a manner that they fall as clear as possiblefromthe main line. Once the last hook of a section of line is outboard, he empties the remainder of the main line still coiled up in the tub by tilting. The piece of line clears itself in the water. P. 229 In the meantime the empty tub is exchanged for a full one. DurIng this time No. 2 has tied the end of the main line of the section of the line thnt is just being set to the beginning of the next section. In addition, he has fastened the lower end of the buoy line to this knot. His third task consists in handing No. 1 thE following section of the line. No. 3 joins the buoy to the upper end of the buoy-line and throws the buoysover board in such a way that they fall dlear - 153 -

Of. the plain line. (In this case buoys with radar reflectors were inserted at.reater intervaLs. These were aupip;osed - to facilitate the recovery 01 the buoys.. They were set from midShip.)" • • • •

The haulinp; in of- the lines.(Fif.?;. 10 h) in decribed• as folloWa by 3teinberg:.

. "No. 1 is on the alert that the main lin aohes on . board clear and operates the switch for the •line - hauler . .

mounted - near the reiiin pulley: .No..2 takes care or. the brunch . lines, hands them over to No. .3, remoVes the-bait, •. from the hook.; dismantles the connection between buoY-line. and main line . and - g ives the other end of the buoy-line to . ' No. 5. No. 3 taker ovEr the hook-lines from No. 2, coils theta up manually, stacks them between the main line coursinr: autoniticully into the tub and hanfY,s the hoohs successively one alongside the othcr on the edge of the tub. Ito. 4 must see that the main line coming from the nne-haulcr falls clenr into the tub stand 'no; on u table alongside the line- hauler. If necessary, he presses the loosely-lyinn: lire

the entire section of the line finds place tor-ether so that

In the tub. Finally, hr unties the knots between the indivi- dual sections of the line and exchanges the full tubs for empLy ones. No. b hauls in the buoy-lines, coils them up and stacks them in tubs specially reserved for the ne lines. "o. 6 loosens the connection buoy-line - buoy and carries -- 154 •-•

full, tubs the buoys FILVity'. iai . No. 7 dbes is to carry the

away from • the line-bailler end . to istOw. them." . . . •

Abb. 10: Aufstellune der Mannscnaft zur Langleinen-Fischerei-. • auf dem ameroikanischen Forschunessohiff '!Delaware" . a) beim Aussetzen b) beim Holen (Steinberg,1963):

Fif". 10: e3tation1n the crew members for a loni-,line Ulicry on the Arnerican research ship "Delaware"

n) while settinfi, lines

b) while hnulinf7 in lines

VIteinberg, 196:q - 55

Finally, in Fig. 11 is shown an example from the

French research ship "Coriolis" (overall length 37.5 m) of New Caledonia. Tactics used on this deck-catcher while setting and haulin in the lines differ from those used in

the preceding examples in so far as the hook-lines are P. 231 always removed from the main line and packed separately.

Abb. 11: Aufstellung der Mannsohaft zur Langleinen-Fischerei auf dom franzdsisohen Porschungssehiff "Coriolis" a) beim Aussetzen . b) beim Holen•

Teie. 11: qtationing the crew members for a 1dIngline fishery on the French research ship "Coriolis" a) while setting lines b) while hauling in lines - 56 -

/s a rPsult there is no stoppage during the hauling in when a fish is caught. To speed up the work the hook-lines are hooked with loops On Clipper-like,so-called AK-clips to the main line (Fig. 12, Uann, 1959). Besides, the sections of th line are not stored separately in a basket or a tub; two such sections are always packed with the still attached buoy lines in a square piece of netting. The unhooked hopk-lines are similarly packed by themselves (cf. in this connection also Mann, 1955).

The fact that the ship has the shape of a deck-catcher &J 5() necessitates a somewhat different arrtIngement of the orew in setting the tune longlines over the deck-pulley

Fig. 11a). No. 1 oasts the main line sternwards. No. 2 attaches the hook-lines to the clips of the main line, No 3 looks after the castinr and the clear run-off of the hook- lines to starboard. No. 4 hands the hook-lines with baited book to No. 2 or to No. 5; No. 5 brings the baited hook- lines cloc7er. No. 5 looks after the clearing of the hook- lincs for No. 2 or for No. 4. No. 7 also assists in bringing the hook-lines. No. 8 and other helpers take care of the baiting of the hooks. No. 9 perhap- assists No. 11 and looks aftcr attaching the floats to the bamboo poles, their attach- ment by means of a loop to the buoy-line and the settIng of the buoys on the port side. No. 10 brings on new sections

ûr the line and ties them together. Abb. 12: AK-Clip zum Anhaken der Hakenschnur an die Hauptleine

Fig. 12: Ak-elip fur hooking the hook-line onto.the

MuiP line. 58 -

Fig. 11 b shows the hauling of th( lines from the forw • rd quarter. No. 1 stands at the hauling machine and supervises the coiling up of the main line in small rings which arc passed on to No. 2. No. 2 also tukes care of the coiling up of the• buoe-line and of separating the sections

of the line. No. packs 2 sections of the line onto a • square piece of netting, ties same together and carries it away. No. 4 takes hold of the clips attached on the main line for the hook-lines and fastens them to a border-line or the piece of netting. No.• 5 regulates the speed of the coiling machine, carries the floats away from No. 9 and keeps contact with the bridge. No. 6 stands at a railing puLley, grasps the hook-lines and the buoy-lines, hands the latter io No. 7, hauls in the hook-lines and detaches them from the clips of the main line. The hook-line is passed . to No. 7, who removes the bait if no fish has been caught P. 232 and who also hauls in the buoy-line, gives It to No. 2, detaches the buoy from the line and gives it to Mo. 5 for stowing a—ay, while the buoy-line g'oes to No. 2. No. 8 and a nimber of helpers coil up the hook-lines by hand, pack them away and guide the hook(dfish On the hook-lines tu the aft(r body, wher( they are pulled on deck by other crew rnerqbers on th( hook-line or, pon-ibly with gaffs, a strong hook fasten(d to a rope, harpoons and loops. 59. -

Ln Fi. 13 are shown.the individual itemà of the

used in thiS case. . ioniTline

. Abb: 13: Beispie1 für . eine ausgelegte Thun- làngleine des franzdsisehen For- sehungssehiffes "Coriolis

1 3: xample of a laid-out tuna longline of the . French reearch ship "Coriolis". •

The lines are set - at a speed of from 5 to 9.5 kno'be:..•

The 'hauling speed depends on the successof the catdh

;) knots). But here, too, tl'ei must, travel at a high• speed. The line'741auling•mnd the coi1ing machine—take 100 of lin per minute.'

As bait are used deep'-froZen CblolabiS saira• (Tacific smury), such as .cuttlefish, smrdines sardigellas Àackerels:, wod-mackerels and herrings. ThrsE are carried alon- in a ." deep-freeze room of the ship. The fat that no live bait is required is a reut advantage of this kind of fishery.

It has alread:/ been pointed out that lare longliners with deepfreeze facilities are suported by s!lall vessels as feeders. In p1 te of this the 19ngr.ne boatd'remm1n at : sea for as . long a-, 75 duy•

D. t.anin -r,. Hooks a rid ]..,c)c)..Ls

(31nce bluefin tufla frequrntly arproached the trawler's fishing in the Uorth 3ca for herring, attenpts have'not been laci:ing on the port of the crew members of the trawler.' te catch them with simple means. •

The,:i made a kind of striking hook a stron, pointed hook, tied loosely to a wooden pole and, In addition, fastened by a strong wire on board. With bait fishEs the tuna was P. 234 • lured close to thE ship's body and then attempts were made tu beat the hook with the pole, if possible, into the gills of the fish. This caused the hook to become detached from - 61 - th6TOle Cnd the.tuna was heaved'by the wire on board .the ship. Many tùna, however, were lost at the.last . Moment ;

. even if the beatiffil., or the hook into the gills of the :fish wus.SuCceSsful (Fick, 1947/48)..

• Attempts made in the North Sea to catch bluefin tuna with loops rom the deck of the fishing steamer seem to have had greater success. While drageing the trawl net, snail fishes were thrown overboard to Jure the tuna. As soon as this was successful, a wire loop was fastened with the one end to the capstan drum of the winch and lashed to a qo pole. The latter was hold •in the water in such a manner that the tuna, when darting toward a bait, would eventually cet into the loop and get stuck there. The thin thread with which the loop was fastened to the pole broke and the loop was drawn toe-ether. It seems that a few tunas were actually caught with this unusual method (Fick 1947/48; Bahr, no year given).

E._Catch . Constructions and Laree- sied Fishirlm_Trtips

It is generally agreed in literature that entrap- ment fishing gear exerts only little influence at present on the world production of tuna and is now only of local importance. Such gear yields far less than other methods. For instance, from the Japanese bonito fishery it is reported that now only 1 - 2% of the yield comes from entrapment gear - 62 - and VariOUS angling methods; with the exception of pole-, and-line fishery (Wa ) dron, 1963).

Fixed stationary fishing gear, such as these installations, are based on the assumption of an active Limmigration of the fish and must fail if the schools of tuna for one reason or the other take a different course. Besides, the setting up of entrapment installations is possible only in shallow water and in places where the currents are not too strong. Their use is, therefore, reslricted to definite places near the shore. All fishing P. 235 methods for tuna described in the other sections of this article are not tied to a certain locality. They can thus alwas follow the tuna to the mot favourable places. Catch constructions, on the other hand, are tied to a place and wUl be successful only where it is quite certain that the fish will follow a migratory course along the shore, as is the Case, e.,g. in Europe in the Bosporus, around Sicily, and Jn a few other regions of the Mediterranean. But even here success is not always assured. Unfavourable weather conditions or changing hydrographical conditions may divert the tuna migrations. As a result, the catches of the cltationary weirs may show large annual fluctuations.

To the catCh constructions to be mentioned-here belonrr, very ancient types of fishing gear; from the original 63:- form of Ruch gear the captured fish could escape again if

• the gear was not closed in time. This makes a continuous watching and observation necessary, such as is known in particular with the gear of the eastern part of the Medi- terranean. Watched gear, such as the catch chambers used for fishing for tuna are in a primitive stage of develop- ment. The throats, typical of the modern entrapment gear, make it difficult or even impossible for the fish to leave again; they thus make a continuàus watching of the gear. the catch chambers, they are unnecessary.a Compared to more recent development.

'Throat-like entrances are not restricted to gear . made of netting. They ,lay already,be a part of tuna weira plaited of wooden material or of Matà. The weir-like aatch, structures made of wood, such as are being used in the

Philippines and in other countries of nouth America in tuna fishery, are, however, older than those made of netting. Their throat-like entrances may still be of a very simple construction. Frequently they are nothing else but more or less narrow slits or simple'steps which make it difficult for the fish to escape.

Finally, we must mention genuine large entrapment gear . made Of netting, frequently of a highly-developed, con- struction. Usuallithey are designated as "pound nets" or, S. C)4

wrongly, also as "set nets" and used In the tibia fi.sherY, . e.g. on the Pacific coast of Japan and in • the:rforthAtlant1àt .: 2. ' fishery Of the U.S.A. and Canada. .They are.fishihg gear that requires a. high stute of developept and frequently . also considerable technical efforts: . But there.aré ale() P.. 23 many pound-nets which have no throatà and must therefore • be watched; after thé fish enter they 'must be closed.by f.• hand. S - •

Thus, there are a number of quite primitive catch structures and also modern entrapment devices used in the tuna fishery. Of these we shall mention here a few main types, namely, the simple watched catch chambers, the dalianes and madragues which must still be watched part time and, finelly,genuine entrapment devices made of Wood or of-: netting which, to some extent, already . catch fiàh autômati- caily;without necessitating any Watching, with:coMPlicated - throat-like devices.

1. Catch charibers

From the Mediterranean fishery it is known that a tuna fishery has been operated there since ancient times. Antique writings repeately mention tuna observation , ,osts which were leased as good sources of income (Bohlen, 1957). lich watch towers are still encountered today, e.g. on the Yugoslavian coast. They are observation posts on sometimes• high'framework from'Whieh extensive stretches of the sea- eôaSt can,be OVerlooked. To the observation posts belong SIMfile . .ohilmbers mede'of netting; their . One sJ4e is formpd' . by the shore. The side from which the approach of the fish In expected is kept . open bY letting the wall of the net down to the grOund.. As soon as it is noticed froMthe .observation toWer that the fieh have. entered the 'chamber, ; the latter is closed by.puiling uP the lowered net wall. . . In Yugoslavia as well an in Greece Small bays are. soMetimea closed off with netting after tuna havé entered the bay (Tiews, 1962). The fi!,..h are removed from-the catch chambers With the sid of other fishing - devicee„ e.g. beach seines.• .

2 . Dalianes 3

The above-mentioned catch chambers must be regarded as the forerunners of the complicatedly built and subdivided dalianes and madragues which today are spread in the Mediterranean

3 The designation "da liane" originates from the Turkish but we do not understand under it a uniform type of fishing devices. In addition to the installations described here such with dip nets (see below) and wooden weirs with built- in trap-like chambers are also designated as dalianes. 66 from the BomporuS, on the oile throUgh the i .Stràit of P. 2,37 Gibraltar and along the Atlantic Coast, on the other aide. The diVision into dalianes and madragues is undertuken here only in order to separate among the large number of construction types the forms set up on poles and protruding above the water from those anchored and suspended with floats on the surface of the water. The two types do not differ as regards, their method of operation and for this reason they are usually discussed together (Belloc, 1961). It may be assumed that gear set up on poles in shallow water is older than gear developed only by advanc3nr1 into deeper water and held by weighi-,s and floats.

nie present—day dalianes of the l'antern'Mediterranéan

are catch sructures Whieh probably may be traced back to the old Byzantinic finherY. They are:still used in the BoeporUs',..: in the Sea of Marmara and in the Dardanelles, in the Black — 1ea as well as along the Bulgarith coast (Willer, 1943; Gaspers, 1951; Kajevski, 1959 ) and the RU.manian 1942). They are catch installations which distinguish them- 9elves throute,h relatively high resistance to currents and siorms. This power of resistance is ascribed to the fact

-ttnt the netting is not connected tightly to the system of poles, but only to the rigging and can therefore yield to the current and to the storm (Kajevski, 1959), 67 -

Fig. 14 •shows a schematic drawing of a daliane whIch in located in the Bosporus near Beykoz and is of special value to the tune fishery (aydinyacizi and Okêr,

1960). It ha s occupied the location since 1553. As is • evident from the illustration, this fishing gear consists of a network- box of varying width with a bottin made of netiing. It is held by rods. The bottom-netting ises step-like from the bottom to the bunt receiving the catch (in Pin;. 14 the left-hand end). The daliane at Beykoz has (1 9(33) a total length of 84 fathoms (appr. 150 m) and a width of. 14 fathoms Eippr. 25 m) at the bunt and of 20 fathoms (appr. 3 3 m) at the opposite end. The mesh aperture amounts to 48 cm. The preserved cotton threads used for the network have u diameter of 2 mm. For the tuna catch the bunt is on the-outside fortified with a stronger piece of netting. flIic network reaches for over the surface of the watEr to prevent an escape or the finh by jumpin', over th( wall of the P. 239 enclosure. On one side iF an entrance which -- just like the bunt -- can be closcd by nettiffq. On LI small platform hi-11 nbovc the ; ,:ear stnnd observers - 11(i control in the monthq from iril to ilunnt from sunrise to -undown any

Ent,r. /Ice of the fiqh. B7 mcann of "leaders" the finl arc rrwt'rms iudeic)nndrr hie dintbncEs into the ddlianes. As nuon a - fish Enter thE dullan the crEw wuitinl_; on guard- b, )utn in notified und the entrnce to the chh.rober is closcd. hy r.lsinr, the bottom-nettinr- the fish are crowded tooTther Abb. 1 4: Ttirkiepher aus clern Bosporus bei Beykoz (na. ch T. Mi) Fie. 14: 'T'urkish daliane from the Bosporus - near Beykoz (aftcr - T. Mengi) 61a -

in tbp last:Section of the Chamber and caughtwith ring.:-nets ' or killed hy.spear-Stabs into the liVer'and.fet.dhed with the aid of a gaff-iike hook out of the water. HOwever, .the captured.tunas May also be kePt as long as.,10 days in the chambers (Tyiengdr, 1957). • •

nimilar forms of catch structures fastened to poles are found in the entire former Osmanic region of influence. From the modern Bulgarian fishery we find descriptions of dalianes which deviate from the one shown in Fig. 14 in so far an they have already a funnel-shaped step-throat through which the fish are held back on both ends of the catch installation (Eajevski, 1959). The bottom of the entire device consists, as in the case of the described Turkish daliane, of network which is raised to crowd the fish together.

3. Madragues

The designation madrague is applied here to all the large catch structures used in the different parts, especially of the Western Mediterranean and beyond it also

along the Atlantic coast to catch tuna and which, in contrast to the dalianes hang on floats and are anchored. The upper edge of the network reaches only to the surface of the water.

Anchored devices can be set up in deeper places than evices connected to poles and they are not as dependent on a soft -' 7,0

underground to 'drivé in the noies. Here, belphp; th. deviceS

culled by the Italians "Tonnara" and • by the French "M.a.dragn.e .

or "Thonaire", .but they• are not being Used . any more., 'The

Ipanlards cari them "Almadraba " , the PortugUése . "Annacao". 2 4 0-

They are ais() being used on, the coaSt of Lybia, TupiSia,

Algeria and • Moropco and are known especially • in • but

!ils° in Corsiba :and oh the Island of Elba. As an experiment

the Portuguese brought madragues tO .the qoast. of...Angbla

(Marchai, 19&2)'. , • . •

,Tust1 as the dalia.nes, so are also the madragues provi ded with "leaders" which may be of considerable length

(up to 3 or 4 km) (Fig. 15) The device itself may, as in the case of the "Tonnare" in 3ici1y be 300 to 400 m long and at the widest place 30 to almost 60 m wide (Fodera, 1961) .

It is divided into different chambers; the i'nnejiostY of

M'ici' ban be closed , if necessary, with network. This network lies on the ground of the different chamber p;ates and con be raised to close the chanbers. The captured. . bina ban thus be guided from chamber to chamber, possibly in United quantities.

The madragues 7lay be of greatly varying type of construction. This applies not only to their dimensions, but also to their division into a varyinfr number Jf chalribers.

The basic principle, however, is the sanie. Througr,11 a leader the tuna is guided to a long-stretched net-chamber whicht - 71

in turn, is usually subdivided into - different chambers. . In the laSt chamber, the "Camara della morte"..of the Italia:11S,. the tuna is'killed. This is it the same time; the .Oniy

• Chamber with netting at the bottom. • Some Madragues •aY . alSo have slit-throats at the entrances to preVent . the . .escare•of the•tuna. This applies, e.g., to the Spanish madragues and to the _Algerian ones derived from the 3panish:- they have on bOth sides of the leader à throat as entrance . into the deVice (Dieuieide et .Novella, 1953.).

Once the tunas arc in the last chamber, the network is raised and the wildly beating-about fish are taken with

gaffs out of the water. floward the end some of the fishermen themselves jump into the net to handle the hooking of the fish. Fodera (1961) describes the hauling of the tune fishery of licily as follows:

"The tuna, on the other hand, are fished from the large boat, where the crew is divided into groups of six men, two of which number called "arringatori" are highly skilled. One of these men uses the short gaff to catch the fish at the throat and another on top of the head. The tuna is then hauled up until its head is on the P. 241 rail. Two team mates stand on either side of the "arringatori" and catch the fish by means of the long- handled gaffs half way down the back and between the ventral fins. The tuna struggles violently, but since -

Abb. 15: Schema einer sizilianichen Madriguare (Fodera, 1961) •'

Fig. lb: Diagram of a qidilian madrague .(Fodera, 1961)

it is on its side every slash of its tail only levers it

further out of the water. When it is balancing on the rail,

two rilore men standing uprie,t on the [,;unwale hook it with

the long-handled gaffs at the position of the anal and

the first dorsal fins. The tuna is now completely out of

the water, with its head resting on the longitudinal ... 73 ....

bulkhèad. The "arringatorin remove .their gaffs•whiletheir, assistants keep a grip on the.fishby the-anal,and first dorsal. All:Other‘gaffs are removed aà - well and the, "arringatori"..exploit . .the jerks'of he fish to slide:it • behind them Into the bat. This Is a dangerous. jOb, for

. a blow from - the. tall •of:a large tuna can kill - a:man..

• It là the first tune of the catch that•are•moSt difficult to heave a board. .After'tenilinutes or sO the •

rest of the-fish in the death chamber either kill each other in their struggles •or can be taken half . dead,".,

1. Large-Sized fishing tra2s• made of woodwork •

In the Philippines tuna-like fish are caught also in the large-scale fishing, traps made of wattlework (Jones, 19G2; Rasalan, 1955). These catch installations are also called "corrals"; they ore used to catch, among othEr fish, the fri,rate mackerel which COMFS close to the shore.

These corrals are built of fishing fences made of split bamboo. They consist of a leader and of wing,s which guide the fish into a fore-court. From here they enter a main chamber which, in turn, may have one or several additional chambers which would then be the actual catch Cambers. Fig.16a g, ives a graphic representation of such a corral, according to Rasalan, 1955. Fig. 1G b shows a - 94

p.

Abb. 16: Philippinisqhe GroBreusen . a) nach Rasalan, 1955, bYnaCh v.Beandt•

Fig. 16; Philippinic lare-sized fishing-traps: a) after Rasalan, 1955; h) after v. Brandt. .

somewhat simpler form of such catch installation from the Baclaren Beach near Manila (1960). The leader, which reaches ail the way to the shore, guides the fish through a several- meter-long entrance into a roomy fore-court. From the latter slit-shaped throats lead into the main chamber and the catch- chambers proper. The apertures arc only narrow slits which, rrtoreov(r, are held together with bast cords. How effective thiq system of guiding is, is evident from the fact that . '75.. after some time even large.(juantitics . of in the innermoSt chambers.

The catch in the innermost chambers is sàOoped P. 243 out with spoon-nets . . The large fore-court can else* be fished put with pure seine-like nets. This takeS place . - ut low ebb, preferably at.night, So that the.fish curt be broUght fresh bn the market. " . •

5._Larze-sized_fishing_trals_made 9f_netting

It has already been mentioned that large-sized fiFdling traps made of netting are used extensively on the

Japanese coast. What was said at the beginning applies also to them. The place where they are set up must conform to very special conditions with regard to current and ground; not everywhere do such conditions exist. There have been p..00d and successful places for a long time already. But even the hydrographically best place will be without success if the tunas do not come here on their migrations or if they change their route. Moreover, the procurement of large-sized fishinir traps runs into considerable financial expenditures. Even if large profitable catches are achieved sometimes, there may be occasions when the gear is completely destroyed in one niACit if the weather is unfavourable. In this con- nection Japanese history reports of old net insurance contracts (Nakamura, 1954). 7.76 -

The'ne fluctuations in the results of:the . .oatch i the hir;11 costs of procurement of the se inStallations,:.and thé , decrease in the nuffiber br tuna in the japanese . coastal' waters since approximately 1942.(Nakamura, 1954; . TakaYamd. 1962) have led to a replaceMent of the original-fiShing gear,.:set - uP especially for the tune catch, by'large-slzed fishing'traps-. which are suitable not only for .tuna'bUt'for the Catch.. many fish species.

These fishing traps are floating anchored traps which are held upright by floats and sinkers. They have catch chambers and 'raiding devices which nay be up to 4 km long and 100 m deep (Uchida, 1962). Originally they were completely made of straw material, but now knotless netting made of synthetic fibres is used more and more for the construction of these large-sized traps.

Fig. 1 7 illustrates such a large-sized fishin P . trap from Japan. This is a remarkable fishing gear , in

RO far as here a step-throat has been built in front of the catch chamber. The trap thus operates automatically and does not need to be watched continuously. Generally, the fishing trnps are of a simpler construction. Fig. 18 shows h large tuna trap from Taiwan, such as is beim- used on the east coast of th1;1 island in particular to catch frir-at( mackerel (Chen, 1960). The wide entrance permits the fish schools to enter unhampered. As soon as they enter r r

Abb. 17: Japanische GroBreuse • (Kask und Hiyama, 1947)

Fig. 17: . Japanese . large -sized . fishing traps (Kask and Hiyamà, 1947)

the watchmen signals the boats waiting at the entrance to

the catch chamber. The trars are then closed, as in the

case of some dalianes and madragues, by the fishermen in

the watch-boats by liftLng the anterior edge or the ground

net. By lifting the cround net farthrr the fish ar( grt.dually

crowded together and squeezed into the catch chamber. From here they arc pulled out with the aid of gaffs. 78 -;

Abb. 18: GroCreuse für Fregattmakrelen in Taiwan (Chen, 1960)

Fi. 18: Large-sized fibhing traps for frigate mackerel In Taiwan (Chen, 1960). . _

In some cases the nets are lifted twice daily. This requires conside-able labour. Attempts to develop mechanical hauling installations have so far not been successful enough to perilit, their co:lmercial use (Takayama, 1962). This makes It understandable why this kind of large-sized fishing trap is of only minor importurce today and is still decreasing in importance. - 79 -

• • F.. Trawl Nets

• bragged gear such as dredges, beam traW1S and dtter- . . board•. nets are not regarded- as catching gear for tuna-like fish . HOwever, in the North Sea even large and strong tUna, such as biuefin tuna ., May be caught. together with herrings in the herring-trawl (Bahr, 1952). To be sure, this must be regarded as an exception. If trawlers occasionally landed bluefin tuna -- as happened in the Gulf of Maine -- these were not fish caught with the trawl net, but rather fish caught by the crew with fishinr!; hook during the for herring (cf. kurray, 1954).

The maller- tuna, On the'other hand, are apparently caught more frequently in bottom t.2aw1 nets and also in . Pelagi.c trawl nets.

Waldron (1962) reports that skipjack are occasionally P. 246 caught with other fish in trawl nets, but the trawl net belongsto that fishing grflr which provider less than 1% of the total. landings. Presumably the tuna-like fish are too fast, especially in the war-ler seas,to let themselves be capt.;red with a trawl net at the customary slow trawling speeds of from 3 to 4 knots. Better results were hoped for with the quicker float trhwl nets. But of an attempt undertaken in 1901 in the Northeast Pacific it is reported that "pelagic trawl dId not take albacore': (Pinkas, 1962). - 80

G. Seine,Nets

MUoh more frequently than with traW1 nets 'tuna, especially- the juvenile forms and smaller representatives,' are caught with .seine nets. This applies tO.beagh'seinés as well as tO boat seines. Such neta: With their:drag lines' and wings are set around a certain area'intended"to be fished, thus preVenting the fish from.eseaping-... Ugually skipjadk, bbnito and frigate mackerel:are• °aught: in this manner.

An account of thé fishery for frigatemadkerel.reads "Shoals of hundreds of individuals appear>during the slimmer. month at coastal fishing reaorts in south western. AUstralia and in the region of Sidney, and numbers may be-oaptUred H .by beach seines." (U0hida, 1962).

Of the fishery in Ceylon and along the west coast• of India for small tuna and frigate Maokerel it is reported (Williams, 1962) that the drag nets Used.have tail ends. 3 to 5 m long, wings 7 to 13 m long and drag lines up to -. . 500 m in length. These nets "usually require 20 to 70 men for hauling operations." It Would appear that the fishery for fflall tuna, in the sense understood here, is widely distributed. However, occasionally large tuna, .such.as the bluefin tuna, are also caught with beach seines (v.. Deurs et al, 1957). -81 -.

H. SurroundiuNets P. 247

By gurrounding nets we understand a group of fishing gear of a greatly•varying kind. However, the all have one thing in common: with them.shoals of fish . can be more or less completely encircled with network not only from the • sides but also from the bottom. The fish shoal thus cannot escape -- at least theôretically neither'to'the side nor into the•depth, The upper limit is formed by the . surface of the . water. With this fishing gear only more or.léss surface-near waters can be fished. •

The following types of nets are regarded as surrounding nets (according to v. Brandt, 1964):

1. seml-encirolitsnets . barrier-like nets 1.1 1.2 spiral nets

2. totally encircling nets 2.1 lampara-like nets 2.2 purse seines

2.3 ring nets.

All these different forms of surrounding nets are used also to catch tuna-like fishes. In particular the Japanese fiéhery knows a number of semi- or completely encircling nets for the tuna catch which,- hOweVer, will not - 82: -

be diacussed'hére .(eakamura,,'1954). Tery. frequehtiythey. are shoveL-like forms of nets and it WOuld'appear :dbubtfül: whether these forms of gear . are tà be regarded also as pelagic seine nets or drag, nets. . • • •

Of greater . eoonomic iftnortance are the . totally., encircling purse seines. It at the Ieginning . of thisstudy. it was stated,that a further increase. in the yields.of the'. • tuna fishery is . expected in the' future.e 'then these hopes were based in particular on these types Of nets.. . .

There are three types of fishing gear whidh completeiyt the fish sohobls from the side and the bottok. r•PheY - encirole differ substantially as regards their construction and their handling. The lampara-like nets reseMble pelagio seine nets P. 248 with bag and, large wingà. Their lower line is shorter than the upper line; this .gives them a ahovel-like appearance . encircling the fish from underneath. The size of the.meshes _ varies in the individual parts of the lampara nets.'

Purse seine nets have upper and lower lines of appro- ximately equal length. With the exception of parts of the margin, their meshes are of uniform size. Only the thick- ness of the webbing twine varies, depending on the use made of the different parts of the net. The rings that-are fastened to the underline are typical of the purse seine and g ive the gear its name. Through the rings runs the _ - 8,3 se-oalled purse line. Once the shoal is surrounded by the net as-if bg à barrel-like cylinder, the net is pulled . together at the bottom by mens of the purs e • line; this will be described in detail farther down. The fish ahaal are thus prevented fromescaping downward.

There are transitions between the lampara nets and the purse seines. For instance, laMpara-like nets have been provided, with rings- and purse lines; this permits them to be closed.more quickly than would be possible• by the encircling wings. These intermediate forms are desig7 nated as ring .nets.

Of these three types the purse seines, so called by the English-speaLine people, are the most important for the tuna fishery. Only they will be discussed here. They are very large fishing gear, in some oases several hundred meters in length and in depth. To their most essential sections belong the parts of the net designated as wings and the bunt, the part which receives the catch. The use of synthetic fibres for the network has contributed to the revaluation of the purse-seinefishery. The most essential progress, however, 'was made in the last few years through the introduction of mechanical hauling installations (powered blocks). As a result the purse seine, and especially the one intended for the catch of small tuna, has become te one of the most highly-developed fishing gear of the world. 84-

' Two different oonstruotiongof purge Seines Are known: purse seines set and hauled-by two .boats . (2-boat . _ . system) and purse seines in which thià work isiarried, out by one vessel (1-boat àystem). With thé presuffiablY . older. . P. 24;D: . two-boat system each Of thé two boat s transports' . One:half . of the'net and while eaoh one of the boats runs:ePproxiMateiy.- - - a semi-oircle,the net is'set . by the twô partioipAting . (even: though frequently not equiValent) boets.around the sôhool. of fish and after Closing . it with the aid of the purse line_ it is again . hauled ln evenly. Throughoilt thià *procedure, the strengthened bunt remains in.' thé centre of the net. With ' the one-boat system, on the other hand, the net isset from: 7 a single Vessel with the aid Of a buoy or of an auxiliAry boat (skiff, dory) 'and also hauled in again .by it from one end. In this case the strengthened bunt must not be in the . centre, but at One end of the net, the one. that was first set. Both constructions, the 2-boat and the more recent One-boat system are used in the tuna fishery.

In both syàtems:the setting of the net is a rather simple procedure. The network is gradually throWn overboard. or it runs off by itself from the ship or boat running A wide circle. The hauling in of the purse seine is mueh . . more difficult and requires considerable working help. • . Pictures of purse-seine fishermen standing as many as . 30 • or more alongside one another to haul the network by hand . on board were, and still are, typical of many purse-seine. - 85 -

fisheries. For this reason mechanical hauling installations were deVeloped already quite early for hauling in the especi- ally extensive nets of the tuna fishery. These installations consist of mechanically operated rollers on deck which take the network together and pull it rope-like out of the water. Great progress was made by this fishery about 1960 when the hauling installation, named after its inventor Puretic power block, was generally introduced. This power block hangs on a beam; it was developed already in 1952 in California. In addition -- as was already mentioned -- network made of syn- thetic fibres was introduced and also the locating of tuna by airplanes (McNeely, 1961). Through these innovations the heavy working process of the hauling was considerably mechanized and adapted to modern work requirements. The number of orew members on the seiners could be considerably reduced. Through this very rapid development -- the California tuna clippers for the pole-and-line fishery changed in a few years over to the more recent purse seines -- the tuna fishery was placed in a position where it was able to compete, in spite of the high costs of the nets, with the pole-and-line fishery which, because of the high personnel requirements, was faced with huge operating expenees due to the high cost of wages (Chapman, 1962).

Fig. 19 shows in more detail the individual operations P. 250 in setting and hauling in the nets using the one-boat system and the Puretic power blocks. e6

The purse seine lies on the quarter.deck•of.the vessel on a'platform which may be =liable. Oh the net lies . the skiff whiolvis connected via the's'o-dalled• bùrst-line with the . bunt,end of the purse seine., By bunt-énd We under- . stand in the one-boat pUrse seine the strengthened end Ofi the net which later receives the catch. Thé skiff.containg, in addition, the secured end of the. purée line;.the cithée end of the purse line runs through•the_ringà Over the purse.

block of the gallôws to• the winch. Sere leads.glgo . the drag line from the.other, the loWest, end Of the:purse.seine; the so-called hauling end. The skiff is .held on the net . by the skiff7.1ine. By means of the so-called, pelican hOok . the skiff can be quickly unhooked and lowered into the-water' when the net is supposed to be set.. Fig. 19 shows the situation when the skiff is lowered lnto_the water.,

After lowering the skiff the ship quickly. resumes its course (8 knots), this clauses the skiff to tiirn and the r net quickly runs off by itself (Fig. 19 b). .'The skiff serves as buoy from' which the circle with the purse seine net is started. It can also move in order to speed up the setting. Gare must be tàken during the encircling that the fish•shoal • does not escape before the net is cloàed on the side and at the bottom. Icaring manoeuvres are carried out with an auxiliary boat, bright-coloured boards are moved up and down' in the water, burning lamps are lowered in „the water, small AU.D. 19: Aussetzen und Holen der Ringwade beim Einboot-Systemi (Erkldrungen irr Text)

F. 19: Setting and hauling in of thé puÉse seine with the - one-boat system (explanations in the text) dynamite bombs and calcium chloride are . thrOwn in the wate'r* or the crew knOcks,on the ship's edge.

<- After the encirclement is obreleted •(Fig. .19*c) and: the entire-net is set the skiff is pulled to the ShiP and the bunt-end of the net. .The skiff . is• pulled to *hands over the ship by means of a hauling line, over the winCh. The bunt-end is hauled through and suspended to the"gallows; • •" here is fastenéd also-the end of- the . purse line over a • •

special mechanism. The line connecting the skiff _and the end . of the net is unfastened and the boat reffiains free in the ring of .the net.

Now the purse seine is pulled together from P. 252 both ends with the aid of the purse line. As soon as the hauling end of the purse.seine reaches the Ship it is hooked to the gallows, just like the bunt-end (Fig. 19 d). Since a considerable pull is exerted on the net by the pulling in . of the purse line with the rings -- with the net resisting • . this pull -- there exists the danger that the ship will be pulled with its'portside into the net. "To prevent this the skiff is hitched to the starboard-side of the ship where' . it exerts a counterpull.

By.hauling in the purse lines the rings of thellower edge of the net aré.gradually concentrated over a short section of the line and hauled close to the ship and finally - 89 -

with stopper chains or special heave line: On debk. -This. brings the encircled Mel shoal over.the.previouslyaideward -. ...: standing . net wall so that the fish dannot*esoapé any - more even toWard the bottom. The 'chains are placed on deok-and, partially bunched, fastened to the starboardaide.

To crowd the fish shoal more and More together,:the first 10 to 20 rings at the haulingend are again 'unfastened or unhooked from the purse seine. The haulineend,la gUided over the mechanioally or hydraulically driVen power bIoék, and the hauling in of the purse seine begins from the end that was last set. The net is evenly a-tacked. .in layers -On - the platform so that it will be ready for the next setting. To make the work easier the platform ià sometiMes rotatable:

As the net is hauled in the catch is concentrated • more and more in the direction of the strengthened end-piéce of the purse seine. Finally it enters the bag-like . expanded bunt. The one side of the bunt islield by the dhip;•the other by the skiff whiOh has in the meantime come near. . With the aid of a pole the latter .keeps itself at a proper distance from the ship. The fish. are further crowded together by hauling in the network located underneath the , catoh portion, in so far as they have not been hauled'in already on board With the rings.

If the catch is sufficiently concentrated, the quickly dying (through the laok of oxygen) fish are hauled àn board - 90

with the aid of a' large scoop netldip nets). Large. tuna • are also heaved on deck by Slings pulled over the tail fin or after several of theM.have been tied together.byifishermen-P.. 253 • jumping doWn among the dying. fish. . • ' •

The two-boat method is operated.similarly, Only the two net ends are hauled in by two boats so . that the catch 'iè tinally cOncentrated in the middle of the net. With .this method, too, an attempt is made to use a mechanically-driven hauling deVice . and thus to avoid a great deal of heaVy manual • labour. 'However, here two hauling installations•aré required (Schmidt, 1960).

The size of the nets used depends always not only on the kind of tuna-like fishes that are to be caught, but also on the size of the ship. It is therefore not possible to give uniform data on the length and depth of the set net or on the dimensions of the network before it is set as well as the thickness of the twine and the mesh sizes. "The object in choice of net design is to obtain the largest catching capacity of the net for the smallest cost of material and

power requirement under actual fishing conditions" (Hamre,

1963). How this optimum oan be achieved has not been clari- fied so far.

For the catch of the tuna of special economic interes

mentioned at the beginning (bluefin tuna, yellowfin tuna, - 91 -

albacore, bigeye tuna, skipjaok:tuna), the length'of the nets was reported as varYing between 5Ô0 and 1000. -M. :1Jsual1e,H these are. one-boat nets. Two-boat nets may be considerably larger; the Japanese use nets of more than 1700 •:in . length:' These measurements refer to.the eorkline,' the limger net edge is usually somewhat . longer.

Depending on the desigrs, the actual length of the network may be correspondinglY larger. The basio design of the purse seine nets is characterized by the percentage by which the corkline is shorter that the respective net size. For the American tuna purse seines the "hang-in" is 10 - 12%, for the Japanese nets 20 to 30%, depending on the size of fish to be captured and on the oceanic conditions. For the Norwegian tuna purse seines the "hang-in" amounts to as much as 40%. This means that there are 100 m of rope for P. 254 80 - 90, 70 - 80 or 60 m s respectively,of ropes. In sanie purse seines the upper and lower selvedge strips are fitted in differently from the main mass of the network. In the selvedge strips the meshes may be stretched horizontally, while in the middle of the network they are, on the other hand, square. Frequently the "hang-in' is not the sanie in all sections of the net, in the centre piece it may differ from the wings. The previously given data are therefore only average values; they would obtain if the entire net was hung-in uniformly. - 92 -

The data on the depth of the nets vary still more than the data on the length. Depths of from 50 to almost 300 m are reported. The ratio of length to depth is reported at 10 : 1 for California purse seines (McNeely, 1961) and at 10 : 2 for Japanese nets (Takayama, 1962). Some purse seines in the tuna fishery have a length-depth ratio of 4 : 1. Because of the varying "hang-in" of the individual net sections the tuna purse seines show oorrespondingly varying depths. Moreover, thé wing ends are frequently oombined . into one triangle àhd are thus oxtail:narrower here.

As was already mentioned above, it is a characteristic of the purse seines that the meshes are of uniform size. To be sure, this applies only to the main section of the net. The tips of the wings and sections of the frame may have larger meshes. It was also mentioned already that there the exist numerous transitions between/purse seines with equal, and the lampara nets with unequal mesh sizes. Thus, the various other net sections of the typical purse seines may be made with varying mesh sizes. This applies, e.g. to the "Cinciole" of the Mediterranean , which has mesh apertures of 120, 150 and 240 mm, where the latter size is ubed also for the main section of the net (Meglio, 1962).

In choosing the size of the mesh it is Of importance to know that the tuna belongs to those fishes which avoid contact with netting that they can see, so that only relatively 9 3 large meshes are necessary to keep a- school- together.: On the other hand, the strength of the *net surface diminishes rapidly as the size •ofthe, meshes increases arid a verystrong.. net is required for the final .concentration Of:the.schoO1 before scooping out the fish and for . preventing them from P: 255_- brealdng through the net Most reports on the mesh size. for the catch of conmerciallY valuable tuna species with purse seines mention mesh apertures of from . 200 to*250 mm (stretched mesh). HOwever i nets with smaller meees Of ' 100 mm and with considerably larger meshes up to 500.mm' are also usecL

Originally hemp was used as netting material, later cotton twine, and now polyamide fibres (nylon, - Perlon-endless) are in general use. .The Japanese recommend also PVA-fibres (Kuralon). The thickness of the twine is given 'as 210d/96 . to 210/168.

The netting material is used twisted as Well as • • plaited. The network is knotted, but recently the knotless method is also being used.

After these general discussions We shall bring here a few examples of constructions of tuna pUrse seines. The.- description by McNeely (1961) may be regarded as "classical"' , California tuna purse seines; it reads as follows» for the (cf. in this connection Fig. 20 4 ): 4The representations of nets usually produce an • - 94 - . . • : "Baeio design 'oharacteristiOs of purse- seine nètè: used in the California tuns fishery are relatively stan- dard, although minor variations exist in•construction Severardhanges whiCh are becoming accepted procedures in design have been incorporated inte) the follOwing:descriP- tive material. • • • • •

Main Body

A typical tuna purse seintis approximately 425 fathoms long and has a depth of about 42 fathoms. The main body sections are constructed by lacing together 7 strips of 100-mesh deep, 4 1/8" (stretched mesh) Gal references to sizes of meshes will be stretched measure -- centre of knot to centre of knot] number 42 (210d/108, with a tensile strength of approximately 304 lbs.) continuous filament nylon webbing 611 webbing and hanging twine is continuous filament nylon treated with a synthetic conditioning agent. To the main body section are laced a oorkline selvedge strip 10* meshes deep of 5"mesh, number 60 (210d/168, about 420 pounds tensile strength) webbing and leadline selvedge strip 50 meshes deep of number 60, 8" webbing. The corkline

(Footnote continued): expanded rectangular picture. However, as was noted above, the sides are actually brought together with a large-meshed netting in a triangle: This gives the net a garland-like Shape whiclimakes possible a large bulge (cf., e.g., Fig. 27). selvedge strip 1s "hung in" to the*oorkline 10% (10 fathoms:, of stretched webbing is hung to 9 fathoms of corkliné):and' the'leadline selvedge strip la "hung . in"12% to.the 7/15" chain leadline. The extra of mhanging ih" ,to:the . is to cOmpensate for the partially pursed or leadline ."(jup-

. ,shaped" configuration of the net attained.during setting

Cutting Strips

Three strips of webbing (cutting strips):10 . :meshes wide made of 4 1/8" number 60 thread, installed between main body sections divide the net into four équal-length Parts. Each cutting strip has 20 equally.spaced . 3" diameter. . galvanized steel rings (zipper rings) attached to the oehtre meshes Come vessels eliminate the.rings and thread the "Zipper" rope through the "cutting strip" -meshea. A 45- 'H fathom 5/8" nylon "zipper" rope is threaded through the • rings and then spliced to the corkline and hitched to the • 5 leadline.

5 ay zipper we understand a line which, guided through rings, extends vertically to the net Wall from the cvrkline to the leadline. With the aid of this line it is possible to divide the catch by using it to pull up the leadline with the chains. A division of the catch can also be under- taken with the aid of the so-called cork-purse lines. -. 96-

Three bunt sections (sometimes referred tà as i!the sacticenor "the bags") are oonstructed by sewing together . 4 strips of 4 1/8", number . 54 thread (210d/150,' apeut 394 pôunds tensile strength) webbing 25 fathomS.in lengtb by -

. 100 meshes deep. 'These sections lie below the eorkline - selvedge strip The first bunt is positioned at the -bunt: end of the net, the second lies jùst beyond the first. • cutting strip from the bunt end of the net, and the third beyond the centre Cutting strip. . • • '

Net Ends

• Net end pieces are constructed of 5" webbing, number . 60 (210d/168), 125 meshes deep by 15 meshes long. The ' 76011; meshes running from oorkline toleadline at the two ends of the net are gathered and sewn to .the , 125-mesh end. section. The "bitter end" of the end section is then gathered and hung to a triangulai'-shaped galvanized steel end bracket. Thu8 a tapered configuration is given to the net ends without any actual cutting of the. webbing.

The end brackets are constructed of steel rod, bent and welded to the'shape of a triangle. A purseline release, attached to the bunt end braeket, is used to disconnect the purseline from the bunt end of the net at the junction point of the purseline and intermediate hauling line. 97

Corkline and Floats

A 3/4" nylon eorkl3ne,, 425 nithott long'; i .ethreadect'

through 7,000: sponge - plastic floats - each bf Whiqh:eleaàuré

6" in diameter and e" in length With a• 3/4" ~ entre Floats are gathered on thé Corkline in grOtips of eight. which are spaced 10 'apart with hangine fastened tolthe" corklipe across each pair of floats'(Fig...4), •

Cork Purse Rings, Bridles, Lines

Ring bridles for the cork purselines are made up of one-fathom sections of 1/2" diameter pOlyethylene'roPe i, and galvanized steel purse rings 1/2" by 4" in diameter are then secured to the centre of the bridles. The ends of the bridles are finally fastened tà the corkline across' 4 of the 8 floats in one group. •

Ten separate cork purselines are made of 5/8" diameter polyethylene line 42 fathoms in lemuth. A 6" diameter sponge-plastic float iq attached to one end of the line end the other end is threaded through 25 successive purse rjnrs and fastened to the corkline. The first cork purse ring is located 10 fathoms from the bunt end of the net. At this point a bow breastline (Fig. 20) of 1" diameter is attached to the corkline. A 5-fathom extension of this section of cork purseline is used during operation of the gear to connect the bow breastline. - 98-

Leadline Materials and Oonstructipn

. The leadline is made up of 7/16" galvanized'steel chain extending the full length of the net. To every fourth link of chain, nylon hanging cord, 1/4" in diameter, is attached toform a chain-to-net hanging strip. The : hangings . have 10". of Slack between.points of attaohMent (i.e. they are 10" longer than the respective dhain • section). Single strand, number 60 (210d/168) nylon hanging twine loosely laàes the dolible-tWine edge of the. leadiine selvedge strip to the hanging cord.

. Dropper-chain bridles are made up of 124 links of 1/4" galvanized steel chain. These ere attached to the chain leadline using split links at 75-link intervals. Spacing between bridles is also 75 links.

Purse-ring bridles made up of 240 links of 1/4" . galvanized chain are attached to the centre of each dropper,- chain bridle with split links.

Seventy-five galvanized "long" links 4" long by 5/8" in rod diameter, attached to galvanized steel purse rings

A Today the rings for the purselines are not attached any more to the double-chain leadline as shown in Fig. 24, but rather on simpléleadlines as was already showh in • Fig. 20. 299

Breast- Leine P. 257 • À ..r."-'- ' 1.—.77:--"7à7 • :

•

Abb, Schematische DarstellUng einer kalifornisphen ThunrineWade . (M.C1■Ieelyi 1961) . /ig.:201 Diagrattiiraàtie preaentation .of a Cal • fornia tuna . purae seine: e.9.-.„_-_.... . „...... „. __T___

■ - p...e_— _,, -2.1:?.r.....;"..) , ;\-- e ‘.

• Abb..21:*Anbringung der Schwimmer an der Korkleine bei der kàlifornischen Thun-Ringwade • (oben rechts Teil einer Korkensehnürleine) • • Fig. 21: Attaching of floats to the corkline of the California . tuna • . purse seine. •

Abb. 22: Anbringung der Ketten an•der Unterleine bei der kalifornischen Thun-Ringwade Fig. 22: Attaching the chains to the lower:line of the California tuna purse seine.

Abb. 23: Verschiedene Anbringung der Ringe für die Schnürleine der kalifornischen Ringwaden Fig. 23: Various methods Of attachment of rings for the'purseline • • of the California purse-lines. --100

1/4" rod by 10" in diameter, are tightly lashed tO the centre sections of the purse-ring bridle, using . number 60 nylon hanging twine."

The lack of uniformity in attaching the purseline - .rings.iS deMonstrated in Fig. 23 ill . which. four different MethodS'of attachment of the puraeline rings is ehown •

Aocording to McNeely, the purseline required for . the California tuna purse seine oonsists of three sections: of the two end pieces 160 and 330 fathoMs long, made of galvanized steel wire 4/8" in diameter and the centre plede 110'fathoms long made of 3/4" steel-wire rope.

As second example follows the description of the P. 259 . purse seine used by the Norwegians for the oatCh of the bluefin tuna. The 'description was given by Hamre (1963):

"The Norwegian tuna purse seine is an one-boat net and consists of two main parts, the wing and the bunt with a transition section in between (Fig. 24). The wing, which constitutes the longest part of the net, is made of very light material as its only function is to make it possible to encircle the fish schools. In the bunt, which is the final section left in the water after pursing• hauling in, the twine is considerably heavier, having and sufficient strength to prevent the tuna to penetrate the webbing when drying up the fish. . The wing is-cqnstrticted bY.lacing . toget4ervertidal strips of 240 méshes each. :These'are. laCed to'.:the cork- and leadline selvedge strips which are.hling-ih -about: 60% to the corkliné, and some percent leàs to thé leadline. In the first nets the Webbing was made of hemp', which waS, later changed to cotton'tWine. At Wesent (13),'thefiSher- men are at the point of changing from cotton to nylon. In most of the nets in use the bunt is made. of nylon, While cotton twine is still used in the Wing.

The cork- and leadline are made up of double 12 mm diameter terylene ropes. Plastic floats are: Diced ln betweetÉ the corkline ropeseig.25a), 12mmtereene:roipe isalso:used: for purse-ring bridles, one pursqing for every,10-fathoMs leadline is the usual ring density.. The lead-Weight .on a 400 fathoms net is about 1200 kg, inclùding the puràé rings. (Fig. 25 b illustrates how the lead-weights are attached to the ground line,) Ten mm diaMeter stainless steel wire . serves as purseline.

Actually, the nets in use differ with respect to details of construction, especially regarding the size of the nets. The original tuna purse seines were.about 200 fathoms long and 30 fathoms deep. Improvements in handling technique and net matériels have, however, made it possible to increase -the net size considerably and the average size - 102 -

at present is roughly some 400 fathoms long and 50 fathoms deep. The increase in net size.has been most eTeotacular. 'in, the wing, and nets are frequently enlarged by adding. Some strips of webbing each year. The length of the bunt,. which is now about 50 fathoms in most of the nets seems to be of - sufficient size for Catching the biggest tuna schools oàourring in_Norwegien waters. The maximum catch,. in one shot was 91.5 tons (71.2 tons gutted' weight):" •

--270W eiON. 50 fd.

5,0

3,5 4,3 34 fd:

Abb. 24; Schematische Darstellung einer norwegisehen Thunringwade (Hamre, 1963) Die eingetragenen Zahlen geben die,Stare der Netzgarne in e mm wieder. . •

Fig. 24: Diagram of a Norwegian tuna purse seine. (Hamre, 1963). The numbers represent the diameter of the twine (in mm). Ab.). 25: 13,ofeb:tijune von SchWimmor - (a) nn0 anAer norweeischon ThunrinCwa43 .j. 0.1(nffire ., 196. 3Y

- Fig. 25: Fastening floats (a) and sinker-(b). to the' Norwegian tuna purse seine. (RaMre, 1963) ' •

The 'most conspicuous fact in - this deacriPtiOiï of the • NOrwegian tuna purse seine is the much lighter'Webbing as compariql tà the already described webbing used in CalifOrnia,- ::'

This greatly increaSes the actual depth of the het.. :111.,e • •P. 261 length/aottial depth ratio of the Norwegian tuna purse:seine' amounts, accOrding to Hamre (1963), to 100 : 11,5 as'oompared. to the California purse seine with a ratio of 100 4.4. . .Moreover, through the absence of zipper- and Cork..- pure lineà and the cônstruction of only one bunt the Norwegian net àppéars- - less complicated.

As third example follow here data on a purse seine

developed by the French especially for the tuna fishery off the West-African coast (Guichenev, 1964). As in the preceding

examples this, too, is a gear for a single vessel equipped •

with a power block. In this example the ship has an over-all

length of 37 m. But in using this purse seine special tactics

are applied to keep the tuna school that is to be fished

'

- 104 -

in one place by means of live bait and to eoncentrate the, fish , school; we shall come back to this later. Fig. 26 reProduces. the purse seine described here. •

250 m 100 50m 50m 50m 1 YT. .10011•1111111111111111111111

400 . 400 400 400 '180 • 1 140 ' • rn I

I . sop ; soo soo 6.0

1 ; . I. . •

II - , 280 . 280 11 1 111110111» , r,--.--...4 —...... --g—,—...... 1.110:

Abb. 26: Schema einer frahzbsischen Thunringwade • (Guicheney, 1964) Die eingetragenen Zahlen geben die Stârke der Netzgarne in m/kg wieder. '

•Fig. 26: Diagram of a French tuna purse seine (Guieheney, 19(54) . . The inserted numbers represent iime the.thickness of the twine in m/kg.

! . "Originally the net had the following charaoteristics: operational length: 1000 m eonsisting of 4 separate parts, ' eaeh one of 250 m; the two centre pieees were identieal so that the length of the net could be reduced, if neeessary s . to 750 m; actual depth: 126.50 m corresponding to 1265 stretehed meshes each one with n mesh aperture of 100 mm. 105 -

Mesh size and thickness of twine: wing: meshes 50 mm from knot to knot (width of mesh), plaited cord at 600 m/kg.

Bunt: width of mesh 50 mm, plaited cord at 400 m/kg.

Corkline selvedge strip: plaited oord at 3 ram (280 m/kg)

Leadline selvedge strip:plaited cord at 3 and 5 mm (280 and 110 m/kg respectively).

Wing: plaited cord at 4.5 mm (140 ni/kg). Mesh wldth

100 mm..

Floats: 6700 net floats at 100 x 160 mm and large bladder for the end of the anterior wing.

Corkline: nylon, cabled, 18 mm in diameter..

Zipper: altogether 3, each one 250 m with bronze rings at intervals of 500 mm and 6abled nylon of 16 mm in diameter; a zipper is a device installed at a certain place of the net with the aid of which the leadline or the chains P. 262 are pulled to the surface to collect, if the catch is poor, the fish at the ends of the net or, in the opposite case, to suitably divide the catch. The zipper consists of a rope attached to the leadline and running through rings which are vertically fastened to the net or to one of the selvedge strips. •

Leadline: the leadline is made up of galvanized chains 14 mm in diameter. - 106 -

•. • Purse rings: the 96 ring 's for the purseiline consist of à copper alloy;, the rings are faetened to hanging lines . of which each one.is madeup of 2 nylôn cords 12'Mm in diameter and:approximately. 2.50 in. in length; for. fastening'ppen hooks are used which permit a quiek removal.

Puree lines: the purse line is a single rope of 22 mm in diameter and 1300 m . in.length.'

During the experimente of 1962-63 use was made of the Possibility to shorten the net to 750 m, sinoe the available

.winch power did not suffice for closing a 1000 M long net. According- to Guicheney, the following changes were under- • taken on the net for 1964:

1. The last section of the met was considerably. strengthened by using instead of a 3 mm plaited cord Such of' 4 mm; . the old blint was attached below.the new selvedge strip so that the entire front end of the net, in 'which the fish are concentrated, was strengthened.

2. A zipper was installed in the net.

3. To lessen the weight the chains of 14 mm in diameter were replaced by chains of 10 mm in diameter."

As was mentioned above, speoial tactics were used with this purse seine together with live bait. The know- ledge of how to use bait in the sardine fishery with purse 1 •7 ,-

seines, on the one hand, and in the:tuna pole-and-11ne fishery with live bait, on the othe'r hand, waà apParentiy employed to good advantage in the: tUna fisheryWith. P.Urae: seines. Here the pure seiner'is accomPanled'bY a. bait" .boat. This-"Appâteur" May be à-smali..rthonier de pêche • fraiche".

The tactics to be employed have been described by the same author (Guicheney, 1964) as follows:

As soon as a school is reported the . bait:boat Steers to the respective place and trieé to keep the fiah-,there• by throwing.out bait. If the purse seiner finds the sphool

.of fish fire, it throws out the bait to - keep . the fish together until the arrival of the bait boat which:then. takes over the school of fish from the purse seiner. The . duration of the baiting varies greatly. It depends on the reaction of the fish.and on the state in which they are - encountered. If we.are dealing with very concentrated and "hot" fish, the baiting will last only a few minutes; but if the fish are greatly spread out or if theY.are deeper down in the water, the manoeuvre to have them concentrate or come up may, in exceptional cases, take several hours.

Knowledge and competence of the fishery captain . on the bait boat are decisive for the success of the• catch. . During the entire manoeuvre of this boat the purse seiner 108 -

keeps a sufficient : distance leeward. The captain of the bait boat is in.continuotts contact.by radio with . the cal> tain. of the purse semer. If, in his opinion, the school of fish is sufficiently concentrated:he notifies the purse semer. The latter approacheb; always leeward, the One

. side-(whigh side depends on the wind) of the stern of the bait boat. The skiff (an Unsinkable *Wooden bOat 6 m long • with outboard motor of 35 hp) is then lowered, the net shot and the bait boat encircled. Throughibut the duration of the encircling the bait boat throws. out an abundance of bait. Approximately 100 m before the circle is closed the machine of the seiner is stopped; braked by the net, it slowly continues its course until at a speed of zero. , • or at least at a very slow speed, it meets the skiff againw."

Then follows the pursing and the hauling in of the net in approximately the above-described manner. •

As fourth and last example we shall describe a tuna purse seine which is supposed to be used on the fishery- technical research ship "Walthe Herwig". Fig. 27 shows a •diagrammatic drawing of the net. To differentiate this drawing from the previous ones, it is presented -- even if not exactly according to scale -- in its approximate form . after the folding of the wings. The total net is 500 fathoms . (= 900 m) long; over this length of net 570 fathoms P. 264 109 -

(= 1026) of new webbing (strétehed) have been itün' ut. For every 88 m of line we have thus 100 m of•webbing. As is customary in the American tuna purse seines, 'the average hanging- 1h coefficient is accordingly 12%:. The of the net amounts to approximately 67 fathoms , ( depth 121 . m).'. The ratio of length to operational depth is thus:7-> às.was also stated abbve for the California purse seine of the tuna' fishery -- approximately 10 : 1.

The mesh aperture amounts to 4i" = 108 mm. Only the two leadline selvedge strips and the reinforced pieces of netting laced to the triangle have larger mesh apertures of 7*" = 191 mm. The net is constructed of individual strips, each 100 meshes deep. Only the upper and the two lower edge strips are narrower. The strips are placed horizontally, in the innermost part of the two bunts verti- cally. The main section of the net is constructed knotless from nylon of approximately 210d/87 = 23 tex x 87 or equi- valent material. In the bunts at the end of the net or near the zipper the thickness of the twine increases to 210d/168 = 23 tex x 168 or 210d/150 = 23 tex x 150. Similarly, the parts of the net adjoining the bunts, especially the bunt-end, have been strengthened (210d/99 = 23 tex x 99 to 210d/41 = 23 tex x 41). 163 165

150 750 150

141

141

147

108

108

105

Abb. 27: Schema einer kalifornischen Thunringwade flir das fischereitechnische Forschungsschiff. "Talther Herwig" 1-* Die eingetragenen Zahlen geben die Fachung der - .0 den Flechtschniiren entsprechenden Zwirne in Td 210 wieder. Fig. 27: 1) iagram of a California tuna purse seine for the fishery- technical research ship "Walther Herwig". The numbers indicate the compartmenta1iz'ation- .0f the twine corresponding to the plaited cords (in "Td 210"). J. Dit Nets

By dip nets we generally understand relatiVely.Small eear the netting of which is hel d. by round. or 'équeré frames. There are, howeVer, also dip nets with the netting:képt spread by transverse rode.. Such dip nets may te.pf a con-. siderable size. But still larger - are the .so-called dIp blankets ("Senktftcherq. These are large net àurfabes . which, held by the four corners, can be lowered in:the water.-; They have neither frames nor crossing rods to , spread the • net cloth. Suoh dip.blahketà are known in the river fishery: : corners of the net blanket are held. On eaph.oné Here two the opposite shores. Dip blankets are also. known in ,tlié P. 266 sea fishery. Here large square net surfaces are 'Iciwered • : into the depth by four boats (v. Brandt, 1964). ,

To the dip blankets belong also forms where two corners are held on the shore while the other two are fastened to two poles protruding high from the deeper water. Such Fr.ear was known in the tuna fishery of the Bosporus (Fig. 28) and can still be found in Sinop on the Turkish Black-Sea coast, known in ancient times already as important fishery place 6 . The outer edge is fastened to two poles standing

6I owe the photo of an engraving,prepared likely by the Italian graphic artist Presiosi or Brindisi and reproduced in Fig. 28, to the kind mediation of Dr. T. Menai of Istanbul. • Fig. 28: Tuna fishery—with dip . net in the SaY'of eebek in.the Bosporus. COloured engraving in the Marine MUseurn in Istanbul from the Second half de ne.prévidus eentury.

-

- •

.1.1a

-

.• . . - . Abb. 28: Thunfispherei yuit'Senktuch in'der - im Suchtvon tebek , . Bosporus. Farbiger StICh 41 Narine—Mueeil.in . Istanbul aus In — der zweiten:Halfte.desorigen . ' • Jahrhunderts. in the water, while the shore edge àf the net clOth is héle from two watchtowers..: It would, liresUmably,:not:be.wrOng.. to assume that the ancient catch installations fôr tuna the observation posts of which . Were-Méntioned already:above in connection with the ancient catch . cionstructionsére- similar dip nets and not madragues " in the.present,senee The Turkish name for this.gear iS, as in, the - above-déscribed catch structures, daliane, in spite of the faot-that the: two gears work according to quite differentprinciplee..:

In the case of large-sized fishing.traps for tuna extensive "leaders" may guide the fish oVer the dip : Cloth,. : Once this has"happened, the Side' walls . are pulled uP. boaltravels over the dip net and the fish are Ooncentrated by a partial lifting of the netting and removed with:landing nets.

Caspers (1951) describes the saine gear'for the " Bulgarian fishery in the Black Sea as "Kefal-Dalian" with a'. . distance of from 25 to 35 m between the poets. In this Case,: too, the fish are guided by a "leader" over the dip net and . their entrance is observed from a watchtower. As indicated by the name, this fishing gear, designated alsO as dafiene, serves on the Bulgarian coast for catohing Mugilidae, but, also , other migratory fish suoh as pelamyds. •

To be sure, tuna-like fish are eocasionally also - 114 • oapturedlwith smaller dip nets. Waldron (1962) mentions' P. 268 , dip nets for oatohing akipjaok tuna in the Japanese fishery.

K4 Gill Nets

• Gill nets 'in the ÉOTM 'of drift nets are regarded . • as oharagteristio catch gear of the pelagic . fishery, 'These nets are espeoially.suitable for Widely . separated sMall *fish sChools or individual fish whan.a large number ofnets are combined into a'so-cailed . fleet to fish large.regicins. - The larger -fishes are caught by gill nets lesà by getting stuàk while trying to swim through the•meshes,.than by getting entangled in the walls of the net (see next section).

It is known of gill nets that their slight visibility may be of decisive importance for the success of the catch. They are therefore made of the thinnest possible material or -- and this has the same effect -- they are made as trans- parent as possible. Thin netting material, however, is unfavourable for the catch of large and strong fishes, such as most tuna. A further disadvantage is the fact that gill nets, even when used as deeply-set stationary nets, can catch only the "surface fish". While Brook (1959) mentions the gill nets as occupying the first place in the skipjaok catch off Peru, many accounts of tuna catch methods do not mention the gill nets at all, since they did not show satis- factory results. In spite of this, the World Tuna Fish .0onterence . of 1962 warns against deaignatingsi11 nets as unsuitable (Rosa, 1963). It may be assumed thatiby:Uaing monofilament for their construction', their affiCiency-would be increased. Experiments carried out in thiS connection showed that, 'compared to gill nets made of endless enthetià Libres, those made of monéfilament produced .a Much. 'larger yield of skipjaok (;3homura, 1962). .

Gill nets are used not only for skipjack tuna, but also with varying success for albacore (Graham and Mann, 1959; Pinkas, 1962) and in Southeast Asia also for other small species of tuna (Takayama, 1962). But larger tuna can also be captured with gill nets. However, in such case they P. 269 act, as was already mentioned, rather as entangling nets. Even for the bluefin tuna gill nets of 100 M in length with mesh sizes of from 140 to 160 mm are supposedly being used in Italy (Tiews, 1962). However, only young fish are caught in same. From Japan it is reported (Yamanaka et al, 1962) that after 1926 gill nets greatly increased in importance for the catch of the local Thunnus orientalis. For the yellowfin tuna, according to Schiffer et al (1962), net fleets made up of individual nets,15 fathoms long and 2 fathoms deep, are used.

In tune fishery gill . nets - are• generally used as drift nets during the night; this precludes a disturbance of thé •

• - 116 -

- catch through the visibility 'of the net. The nets are set transversely . to the direction . of the current from whioh the fiSh'are expected. The drift nets are attached to bubys;

fràm the behaviour of the .latter it dan be judged whether . a 'fish has been baught. in the nét.'. The respective net is then imMediately. hauled in. This. May happen several tiMed . during. the nighti Toward morning all nets •are - taken . up . (Nakabura., 1954). OccasiOnallygill nets are alsà used'as anchored P: 270 stationary nets in tuna fishery (Scheer etal- , 1962;. TlewS, 1962)*. • .

The construction of the nets (Fig..29 a) varies

greatly as to size of meshes and thiôkness of net twine, always depending on the size of the-fish to be 'caught.

This applies also to the fààtening of floatS and Sinkers. •

Just as some salmon drift nets, those Used in the tuna fishery have sometimes no sinker (Zusatzu, 1940). Nets for' larger tunas which are supposed to act rather as.entangling nets have, on the other hand, the usual weights.

L. Entangling Nets

. As was already shOwn in the preceding sectiOn, gill

nets, espeoially small-meshed gill nets, act . as entangling nets toward larger fisheS. This makes a division between the two catch methods very difficult. •‘

117 ‘-•

Three-wall nets are to be regarded as genuine entangling nets (Fig. 29 b). Deir (1962) MentiOnS their use in Turkey for the catch of pelamyds In the bluefin fishery efurray 1953 and Tiews, 1962) fishing attemptà with three-wall net à proved unsuooessfUl. »

a.

Abb. 29: Setznetze fiir Thune a) Kiemennetz, b)Dreiwaudnetz (Graham u. Mann, 1959)• •

Fig. 29: Set nets for tuna a) gill net, h) three-wall net (Graham and Mann, 1959) -.118 -

ImDortance of Various Fishing Methods .

If we examine the various contributions submitted to • the World Scientific Meetihg ofl, Tunas and related Species with regard to the employed for the individual tuna species we find that they conform -- to

the extent that the species enumerated here at the beginning •have been taken into consideration at all -- to the compi- lation reproduced in the accompanying table. Here the more important fishing methods were included. The fishery with harpoons, stupefying agents, rip hooks, snares and trawlnets was no,t considered here due to their minor importance. Hand- lines and pole-and-line fishery with live bait were combined • in one column, so also were the fishery with gill nets and with three-wall nets. Combined were also trap-like gears under the heading "catch constructions and traps" and the beach and boat seines under the heading "seine nets". The concept P. 272 •"surrounding nets" means not only purse seines, but also gear used in a similar manner, usually in a lampara-like

form. •

Included in the table are also species of fishes for which a specific fishery does not take place, but which are caught along with other fish when fishing for the latter, as e.g. in the Pacific and Sarda sarda in the Western Atlantic. Hand lines, especially with live •

- 27 1 P. 118 - b

TabelleL • ,Fang- Hand- Schlepp- Lang- Fang- Zug Uirt gebiét ) angel angel bine bauten'netze. schlies- mcn- und . sungs-, netze Reusen netze„ Tliiib ii us thylnlus • • • Paz, .

Kalifornien Th . Paz.uInd. .+

Th . albacores

md Westl.Atl. Th.obesus + -+ Paz. . + Kalifornien + . + 'fi t tj.cus Westl.At.l. • + •.› - Eu thynnus pelamis + + Ind. . Paz. + E..allettera- tus Westl.Atl.

und'Ind. + + • • + E.affinis. Ind. Paz. U. J. I. n eatus Paz. Sarda sarcla Mitt, + Westl.Atl. S.orienta- lis Paz. AHX0 tha- zard mcl Paz.- A.rochei Ind.u.Pau. +- '(irammater- • cvnus bi- carinatus +

x. ) Abkürzuneen: Atl.=Atlantik, Ind.=Indischer Ozean, Mitt.=Mittelmeer,. Paz.= Pazifischer Ozean. ") Abbreviations: Atl. - Atlantic, Ind. - Indian Ocean, Mitt Medi- , terranean-Sea, Paz. - Pacific Ocean, Westl. - Western.. • Fano..ebiet -- Fishing rection Handangel -- hand line • Fchleppangel-- troll line Langleine longline Fangbauten und Reusen -- catch constructions and traps Zugnetze -- Seine nets •Umschliessungsnetze Aurrounding nets - 119—

bait, and also, with one exeeption, troll lines are mentioned

as fishing gear for all listed tuna speoies. Then follow at approximately equal frequency longlines, eatoh construc- tions emA traps, as well as purse seines. The importanoe of the individual methods in tuna fishery has greatly changed in recent years. Thus, a gradual development from the simple hand- and troll-line fishery to the pole-and-line method with live bait and still farther to the •longline or the purse seine has become more or less pronounced. This development follows the law observed generally in the fishing- gear development to proceed, if possible, from fishing for individual fish to mass fishing. Especially conspicuous was this development in the California tuna fishery in its

• transition from the pole-and-line method with live bait to the purse-seine fishery and in the French tuna fishery where the troll lines were replaced by the pole-and-line method with live bait and where now a purse-seine fishery with live bait is taking place, at least off the West-African coast.

Data on the share of the individual fishing methods in the total catch are contained inbartiouler in the Japanese fishery statistics. For Thunnus orientalis Yamanaka et a1 (1962) give the following general survey for Japanese . waters, converted into percentages of the total catch: - 120

1953. 1954 1956 1959 .

Purse seines .42' 148 ece Traps 14 . - 35. 15 Pole-and-line 22 30 19 _8% Longline 22 11 18 *16%

Brook (1959) gives the following data 'on the ,.P.-27Z . catch of all tuna *species of Japan:

1952 1.957

Pole-and-line 61 * 42% Longlines 31 52%

The latter figures indicate the succeséful expansion . .. of Japanese tuna fishing with the longline. This depressed - the prices and some fisheries with hand lines and live bait were forced to close down their fishery or to eut down their. operation. •

With the change of the fishing gear a change in the, share of the different tuna species in the total catch and also a' changein the composition of the catch with regard to the size of the* .fishes frequently:takes place These changes need not necessarily be due to biological causes, nor to the demands of the market. • Methods using liVe bait • must e.g. be given up if the latter cannot be probUred any. 7 121 more (th some cases as the result of an extension of the sovereign territory which do not permit any more bait fishing near the shore). For the Japanese fishery Brook (1959) provides a compilation showing that with the use of the , different fishing gear for albacore the size of the fishes changes. It inereases in conformance with the sequence of the following fishing methods: smallest fishes during the summer with gill nets in the Central North-Pacific. Approxi- mately the same composition as to size at the end of the year with trolling lines along the American coast; larger fishes are caught with the longline during the winter in the North-Pacific and during the summer with pole-and-line und live bait on the Japanese coast. The largest fishes are caught throughout the year with longlines in the tropical Pacific. A similar compilation for a size selection by using different fishing methods shows for the yellowfin tuna that the smallest fishes are caught with hook and line and live bait on the American west coast, larger ones with troll lines around the "Line Islands" and the largest fish with longlines in the sanie region. Both compilations indicate quite generally that large tuna are caught practically, only with the longline, the only gear reaching somewhat greater depths.

In reviewing the various tuna fishing methods the. P. 274 World Scientific Meeting on the Biology of Tunas and Related - 122 -

Speeiés reaohed the following conclusions (Rosa, 196 3).: .of the pole-and-line fishery with live bait, of importanee . for the yellowfin tuna, the albacore, and espeoially the skipjack tuna, a further -- even if not very significant -- progress is expeoted in the tropical waters, in spite of the frequently existing difficulties in procuring live bait. Of the troll line fishery, especially for albaoore, yellowfin tune, bluefin tuna, and skipjaok tuna, growth is hoped for in many parts of the world because of its simplicity and the absenoe of the difficult bait procurement. It is admitted that the longline fishery is the only one reaching the larger fish farther down. It is feared, however, that in many regions it has already passed its highest point. As to gill nets the last has not been heard of them yet, as was pointed out above. Better results are expeoted from the use of monofilament nets; reference is made to a similar development in the salmon fishery. The purse-seine fishery is, through the most reoent improvements (synthetic netting material, power block), again regarded as competitive. Since at the time of the conclusion of the Congress the combination of the bait method with the purse-seine, developed by the French espeoially for off-shore smaller tune species, was apparently not yet known, it was assumed that the purse seine could be used only in seas with a high interface. Under the impression of poor experiences made with purse seines on the West-Afrioan coast the possibility of net losses through sharks is pointed - 123 -

out Finally,.of large fishing trap's, it is stated that, while they may be of lcipal importance, they will have no , .-eftect on the total tuna catch of:the world. .

- 475 - 1; 11:1112mullx - 124- Schrifttum .

Arnoll', B. : Contribution to the .in the Seuthern Soap. Uppsala, 1955. Aydinyamici, A. und A. dker: On fiàh traps in the Bosphorus and . Surroundings..

Part.i. Dank ye balikcilik VIII,.No.7 1 . • 19-22, 1960 (TürkisCh)e •

Bahr, K. Untersuchungen über den Roten Thùn'(Thunnuà . thynnus L.) in der Nordsée... • Derichte der DWK, XIII, 647i.3, 1952. • Dahr, K. . : Sportlicher Thunfischfang.. • Schriftenreihe des Verbandes . Delitscher 'Sportfischer,Heft 11, o.J. • Belloc, G. : Inventaire des madragués mditerraneans. Cons. Genbral des . Péches pour la 1\iditerran&e

No , 6, 345-371, 1961 , Bohlen, D. • : Die Dedeutung •der Fischerei. für die antike - Wirtschaft- Diss., •iamburg 1957. Dorrel, A. : Les pëches sur la côte septentrionale de. la Tunesie. Mem.du.Centre des Sciences - Humaines Vol.II, 1956. - • • V. Brandt, A. • : .Fang des Weissen Thuns an der franzbsischen Atlantikkllste.• Fischereiwelt 8,•55-56, 1956. V. -Brandt, A. : Fish catching methods . of the world. London 1964. • v. Brandt, A. : Zuni Donito-Angeln zwischen Fayal und Pico (Azoren). Fish und Fang 5, 6-8, 1964. • v. Brandt, A. und R. Steinberg: Fischereimethoden der Kap Verden.- Prot.zur Fischereitechnik,. IX, 63-80, 1964. Brock, V.E. : Tuna fishing methods and their application. Tuna Industry Conference papers Bureau of • Commercial Fisheries,.May 1959. Caspers, H. : Die bulgarische Fischerei im Schwarzen Meer. Abhandlungen aus der Fischerei, Lfg.4, • 719-786, 1951. • Chapman, W.M. : Recent trends in world tuna production and. some problems arising therefrom.. Manuscript 1962. Chen, C.T : A survey of fishing gear used in the coastal fishery of Taiwan. 1960 (Chinesisch).

1For translation of— German titles see p. 129.and 130, r

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Chen, C.T. und T.L.Wu: An investigation report on sma1lUo,at • tuna longliner.• . . . • Nr. 1, 1955 (ChinesiSch). . • , . . -. • . . Cleaver, P.C. und D.M.Shimada: Japans Skipjack (KatsuWonü .s' _ • pelamis) FiShing Methods. ' . ‘• \ Comm.Fish.Rev. 12, No.1I . ,.1-27, 1.95(5.', Demir, M. : Synopsis of biological . data on Bônito, Sarda sarda, World Sc.Meeting . onllie, biology of Tunas and related species:' SpecieS Synepsis . No. 1, 1962. v. Deurs, J.A.S. u.a.: Havet eg Fiskerierne. Kopenhagen 1947. Dieuzeide, R. und M. Novella:'Le matérial de pêche maritime utilis6 en Algérie. . , • • Algir 195 3. . . . Fodera, V. - : The Sicilian Tuna trap. Studies and RevieWs No.15,1961.' FAO.GFCM.

da Fonseca, J.B.G. : Preliminary experiments with Tilapia aS bait in the Tuna Fishery off the coast of Brail. World Sc.Meeting on the Biology of .Tunas and related Species. Exp.Paper No.l i 1962. ,- Godsil, H.C. : The high seas tuna•fiShery in California, Bureau of Marine Fisheries.Fish.Bull.N0,5 1938. Graham, J.J. und H.J.Mann: Construction and catch selectivity of Albacore gill nets used in the Central North Pacific. Comm.Fish.Rev.21, No.8, 1-6, 1959. Guicheney, F. . z Compte rendu des premiers essais de 'Ache. au Thon tropical à la senne du thonier senneur "Danguy". Science et Pêche No. 128, 1964 , Ehrenbaum, E. : 'Libor die Seefischerei in den osmanischen Gewassern. Fischerbote IX, 77-87, 1917. . . Fick, H. : Thunfischfang'mit der Angel. Die Fischwaid 1, 83-87, 1947/48. Hamre, J. : Some technological aspects of the Norwegian • Tuna purse seining fishery. Rep.on Norw.Fishery and Marine Investigations' 13, 106-119, 1963. 'Mornell, J. :Fishing in.:I:any waters. London 1950, Howard, G.V. : Tuna harvest. Fishing News Int. 1, No.3, 22-29, 1962. Ivanivi, V. : Modern , London 1954. - 126 - VI ^ - 277 . • , Iylgiingr, D. : Méthodes et moyens de pÔche au thon . V' actuellement en usage en Turquie ConàGnral. des Péches pour la • • • - Méditerranée, No.4, 1957. J(mcs, S. : Synopsis of Biologidal Data On the loncç corscletted Frigate Mdekerel ThynnoideS... World Sc .Meeting on the biology of • Tunas and 'related Spoies. Species Synopsis No.28,1962.: Iron Works Co. Ltd.: Power holer for longlines.• Medern. Fishing Gear . of the World 436-437, 1959. A.ajewski, G. : Der Entwicklungsstand .der Seefischerei 3u1,- garienS. Fischereiferschung 2, 6/7, 3-8, 1959.. .Aask, j.L. und • Y. Hiyama: Japanese fishing gear. US Fish and Wildlife Service Fishery Leaf- . let 234, 1947. ';.ri.utzer, C. • ; Tuna are caught by electric:hooks. Comm.Fish.Rev.13, No.10, 25,, 1941. • MCernick, H.W., T.Allen und W.Young: ShadowS in the sea. Philadelphia, 1963. • McNeely, R.L. : Purse.seine revo.lution in Tuna fishine.• • Pacific Fisherman-59, No.7, .24-58, 1961. • . Mann, M.J. : Construction details of iMproved Tuna long-, line gear used by Pacific Oceanic fishery • investigations. 'Comm.Fish.Rev.17, No.12, 1-10, 1955. Mann, H.J. : A new method of handling longline gear, a description of POFI "Tub". Gear. Modern Fishing Gear of the World, 430-432, 1959. Marchal, E. • : Expesé synoptique des données biologiques . Sur la Thouniere (Euthynnus alletteratus). World Sci.Mecting on the biology of Tunas and related Species. Species .Synopsis No. 20, 1962. Di Meglio, A. : Les filets tournants a thons sur les côtes francaises de Méditerrané. Science et Péche No , 101, 1962. Meyer-Waarden, P.-F. : Erfahrungen mit der elektrischen Thunangel. Fischereiwelt 3, 1.76-17 8 , 1951. 1:ur:c'ay, : Gulf-of-Maine Dluefin Tuna Exploration 1953. • Comm.Fish.Rev. 16, No.7, 10-19, 1954. Naai, N. : Study of electrical tuna trolling. .(nach Takayama, 1962). .kamura, H. : Tuna longline fishery and fishing grounds. US Fish and Wildlife .Service Spec.Sc.Report - Fisheries No , 112, 1954. - 278 - 12 7,-

Norman, J.R. und F.C.Fraser: Riesenfischo, * ale'Und:Delphine w . • l'ibersetzt und,bearbeîtet von '.G.Krefft-und • W.SChub rt, 1 . • • Pinkasi-L. : Albacore sçouting'in the. Eastern. North. Pacific Ocean.' • World Sc .Meeting on the biology of TUnas. and related SpecieS. Experience Paper 19 • • • • Rasnlan, S.D. : The new Hasang Moderne, a.fish.Corral,Used . in the Philippine. welter The Philippine journal of•FisherieS 2,. 211-235, 1955. Ritzhaupt, H. : Die Fischerei Kubas und einige MÀigliChke-iten ihrer Intensivierung . Fischereiforschung 1, 1-19,...1963. Roba, H. Proeeedings of-the:world seientific meeting on the biology of. tunas and related species, FAO FishiRep.No.6,.:Vo1.1, 1963. . SarA., R, : Data, observations and comments on the . occurence, behaviour, characteristics and migrations of TUnas in the Mediterranean._ GFCM Proceedings'and Technidal . Papers . .No.7,- 3'71 _38 8 , 1964. Schaefer, M.D., G.C.Droadhead and C.J- .0range: Synopsis •f the • :- biology of Yellowfin • . . World Sc.Meeting on the Biology of.Tunas and related Species. Species Synopsis No.16, 1962. . • Schmidt, P.G. : Purse seining: Deck design and equiPment.'• Fishing Boats of the . World 2, 31-55, 1960. • Shomura, R.S. : Monofilament gill net fishing for Skipjack Tuna in Hawaiian waters. World Sc.Meeting on the Biology Of Tunas and related Spees, Exp.'Paper No. 10 , 1962. Steinberg, R. : Dericht über die Forschungsreise des US-amé- rikanischen Forschungsschiffes,"Delaware". im Gebiet wischen den Azeren und.Mndeira, in der Zeit vom 7.-14.5.1963 (Unverbffentlich-' ter Reisebericht). Sund, O. : Die Norwegische Seefischerei, Hdb.der Seef.Nord-Eurepas VIII, 1-181, 1938 Svendsen, L. : Thun, Fiskeri of Tùnfisk. Kopenhagen 1949,' Takayama, S. : Fishing techniques for Tunas and Skipjack. Werld Sc,Meeting on the Biology of Tunas and •related species. Metholog.Paper No., 1962., Taylor, F. : The Tunny in Sea Fishing. The Lonsdale Library Vol XVII, 189-211,o.J. 1

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Thiel, H. : Thunfisch und Thunfinchfang. . . Der Fischmarkt 6, 115-121 und 128-13•,1938. • Tibbo, S.N. Und,R.A.McKenzie: Tunas and Bonitos. . Fish Res.Board Of Canada, Bul.Stat.St. AndroWs, N.B., General Sono Circular No. 43, Ahg.1964. TioWS, K. : Synopsis of biological data on Bluefin -Ttana, • •Thunnus thynnus (Atlantic and Mediterranean).' . World So.Mecting on. the Biology of Tunas and related Species. Species Synopsis 12., 1962, Tiews, K. : Die Thunfisherei in doutscher Sicht. Bas Fischerblatt 12, 85-88, 1964. • Uchida, R.N. • • Synopsis of biological datn on Frigate Mackerel Auxis thazard (Pacif.Ocean). World Sc.Meeting on the biology of .Tunas and related Species. Species Synopsis No.8,1962. Van Camp Sea Food Company: Sea Food Handbook. o.J. *Waldron, K.D. : A synopsis of biological data on Skipjack, - Katsuwonus pelàmis L: (Pacific Ocean). World Sc.Meeting on the Biology of Tunas- and.. .relnted Species. Species Synopsis No.22, . 1962.

- Willer, A. : Rumiiniens Fisherei. - Die dtsch. Fischwirtschnft 9, 521-523, 1942. Willer, A. : Die Fischordi Bulgariens. Die dtsch. Fischwirtschaft, 10, 301-305, 1943. Williams, F. :* Synopsis of 'biological data on Little Tuna, . World Sc.Meeting on the biology of Tunas and • related Species. Species Synopsis No,5,1962. Wilson, P. C. : A small-boat tuna'long-line fishery. Comm.Fish.Rev.22, No.9, 8-13, 1960. • Yamanaka, H. u. a. : Synopsis of biological data on Kuromàguro •hunnus oriontalis (Pad.Ocean). . World Sc.Meeting on the biology of tunas and related Species. Species Synopsis Nb.6,1962. Zusatzu : Hokkaido Gyoyu. 19 110 •(Japanisch). — 12.9 .-

Jlibliographv (Transiation of Garman titleS)

Bahr, K.: Investigations on the bluefin time (Thunnus • thynnus L.) in the North Sea. ' Bahr, K.: Sport tuna fishing. Bohlen, D.: The IMportance of fishery for the ancient economy. v. Brandt, A.: Fishing for albacore on the French Atlantic coast. v. Brandt, A.: On line fishing for skipjack tuna between Fayal and Pico (Azores). •v. Brandt and R. Steinberg: Fishery methods of Cape Vérden. Caspers, H.: The Bulgarian fishery in the Black Sea. .y. Peurs, J.A.S. et al: The Sea and fisheries. Ehrenbaum, E.: On the sea fishery in the Osmanic waters. Fick, H.: Tuna fishing with fishing line. Kajewski, G.: The state of development of the Bulgarian • fishery. Meyer-Warden, P.-F.: Experiences with the electric tuna fishing line. Norman, J.R. and F.C. Fraser: Giant fishes, whales and dolphins. Translated and edited by G. Kreft and K. Schubert, 1963. Ritzhaupt, H.: Cuba's fishery and some possibilities of its intensification. Steinberg, R.: Report on the exploration journey of the USA research ship '"Delaware" in the region between the Azores and Madeira from May 7 to May. 14, 1963 (Unpublished beport). Y '

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Sund, 0.: The Norwegian sea fishery.

9vendsen, L.: Tuna, fishery of tuna fish. Thiel, H.: tuna fishes and tune fishing. ' Tiews, K.: The tuna fishery front a German viewpoint. 'Willer, A.: Rumania's fishery. Willer, A.: Bulgaria's fishery.