bait species effectiveness

7/28/2019 Bait Species Effectiveness

1/12

MFR PAPER 1060

S u c c e s s o f t h e l i v e- b a it t u n af i s he ry r i des on t he s uc c es so f t he f i s he ry f o r ba i t .

Some Considerations of the Problems Associated with the Use ofLive Bait for Catching Tunas in the Tropical Pacific OceanFRANK J . HESTER

ABSTRACTbait, fishing the tuna schools, andbait supply.TYPES AND CHARACTER~ST~CS

Thi s rep o r t p ro v i d es (I . sui nni ti ry o f t ro p icc rl P ~ i f i c icnci l i v e -b a i t f i sh i ngm e t h o d s , i d e n t i f i e s th e n ia j o r proble ir i s restr ic t ing the cxprinsion of l ive-briit

f i sher i e s i n th e Pmij ic , a nd g i ve s re fe rences c i nd sicggestions o n ni e t l i o d o l o g yto i nve s t ig t i to r s i n t e re s t ed i n wo r k i ng on hciitjish p r o b l e m s . OF A GOOD BAITFISHINTRODUCTION

The use of live bait to catch tunas,called baitfishing in the eastern Pa-cific and pole-and-line fishing in thecentral and western Pacific, has beendescribed by a number of authors(Godsil, I93 I ; June, I95 I ; Iwasaki,1970; Isa, 1972; and Webb, 1972,1973). The method probably wasdeveloped to its highest form in Japanfrom whence it spread, with modi-fications, across the Pacific and intothe Atlantic during the first part ofthe 20th century.

The 1971 world tuna landings were1,150,000 metric tons (FAO, 1971).Of this total catch, baitfishing ac-counted for about 244,000 metrictons (2 %), purse seining took 228,000metric tons (20% ), and longlining took427,000 metric tons (37%). The re-maining 25 1,000 metric tons (22%)of tunas were taken by a variety ofmethods such as trolling, and trapsand weirs, or were caught by thethree principal methods but couldnot be so identified from the statistics.

For a description of tuna purseseining see McNeely (1961) and

Green, Perrin, and Petrich (1971). In order to be a suitable live bait,and for tuna longlining, Shapiro the baitfish must be of a size and(1950). appearance acceptable to the tunas,

Live-bait fishing for tunas depends its behavior must be such that theupon quantities of suitable baitfishes, tunas are attracted to the boat andwhich are used to attract schools of induced to bite, and the bait musttuna to the boat and to excite them be sufficiently hardy to remain aliveinto a feeding mode so that they can during capture and transport. In thisbe caught by lure and a pole and regard resistance to mechanicalline. The principal tuna species taken damage, i.e., loss of scales and bruis-with baitfishes are skipjack tuna, ing, is important, as is the baitsKtrtsrtwonir.s p e l o i r i i s ; yellowfin tuna, tolerance to temperature and tempera-Thirnnrrs crlhaccires; and albacore, ture change so that the bait can beT. trltilirngci. The live-bait albacore carried by the fishing boat from onefisheries are in temperate waters. The fishing ground to another throughdiscussion of live-bait tuna fishing waters of varying temperatures.in this paper will be limited to the The preferred baitfishes for tunatropical tunas-yellowfin and skip-jack. Five elements of baitfishingfor tunas will be reviewed and dis-cussed: types of bait, catching thebait, holding and transporting the

Frank 1. H a t e r was formerlyDirector, Honolulu Laboratory,Southwest Fisheries Center,National Marine Fisheries Ser-vice, NOAA, Honolulu, HI96812; present address, 1135High Road, Santa Barbara, C A93108.

1

fishing are clupeoids, principally theanchovies and their relatives. Theclupeoids in general are good baits,being of the proper size (25-100 mm)and possessing the silvery appearanceand the behavior that induces feedingbehavior i n the tuna. These fish areactive swimmers that do not dispersewhen thrown into the water but main-tain a semblance of schooling be-havior and do not swim away or divedeep but stay close to the vessel.When suitable supplies of clupeoids


2/12

Area andwriodEffectivenessUnit of Tuna catch Kilogram bait/Bait species measure Quantity (metric ton) metric ton tuna

J apan. 1968'

J apan. 19712

Hawaii, 1965-713

Eastern Pacific ,1948-594Eastern Pacific.1960-694Palau Islands.19665

Ryukyu Islands.19676

Hawaii. 19627

Hawaii. 19688

Hawaii. 19719

Hawaii. 197310

Hawaii. 197311

Anchovy, Engraulis

dojaponicus

Anchovy (nehu). Sto -liphorus purpureus

Anchoveta. Ceten-graulis mysficatusdo

Anchovy (nehu).StolephorusheterolobusMixed-predominantlyapogonids and Iut-janidsTilapia. TilapiamossambicaShad, Dorosoma

petenenseShad, DorosomapetenenseNorthern anchovy,Engraulis mordaxGolden shiner.Notemigonuscrysoleucas

BucketI.5 kgBucketE 5.5 kg

BucketI .5 kg

SCOOP

SCOOP4.1 kg

4.1 kgBucket=3.5 kgKilogram

Not avail-ableBucket

=3.5 kgBucketE 3.5 kg

BucketI .5 kg

BucketI+ 3.5 kg

4.4 X 1W buckets

250 buckets1.375 kg34 X 103 buckets0.8 X 10s kg

3.5 x 1WscooPs14.5 X 106 kg0.41 X 1Wscoops1.7 X 10s kg62.7 X 103 buckets0.22 X 1W kg

0.27 X 1W kg

Not available

56 buckets176 kg204 buckets728 kg3 buckets10.5 kgNot available

168 x 10371.9

4.5 x 103

114 X 103

23 x 1032.9 x 103

5.1 x 103

Not avail-able4.8

12.5

0.7

Not avail-able

143.0

19.4

28.50S2 =51(variance)128.1

Y = 783682St = 15887.4S = 1008.852.6

=6037

58

15

118

I Based on total anchovy bait catch and total home and southern waters landings of yellowfin tuna, skipjack tuna. and albacore.2 Based on average bait capacity and average catch per trip of southern waters vessels (Anonymous. 1971).3 Source: Hawaii Division of Fish and Game and Bumble Bee Seafoods (1970).4 Source: InterAmerican Tropical Tuna Commission (1956. 1960. 1968, 1970). Note: From 1960 on most of the large bait boats converted

to purse seiners and left the bait boat fleet.5 Source: Congress of Micrones ia (1972).6 Source: Isa (1972).7 Source: Shomura (1964). Quantity and weight of bait not given. Results are based on average catch rate comparison with nehu.8 Source: lversen (1971).9Source: Iversen. R. T. B. 1973. Commercial fishing for skipjack tuna with threadfin shad as bait. Unpublished report. 4 p. Southwest10 Source: Uchida. R. N.. Southwest Fisheriea Center. National Marine Fisheries Service, NOAA. Honolulu, HI 96812. pers. comm.11 Source: Kato, K., Fishfarms Hawaii, P.O. Box 898, Kihei, HI 96753, pers. cornm.

(Source: [Japan.] Ministry ofAgriculture and Forestry. Statistics and Survey Division, 1970.)

nehu being considered tohave an effectiveness of 30.

Fisheries Center, National Marine Fisheries Service. NO M, Honolulu, HI 96812.

are not available, bait boats, espe-cially those operating in island areas,resort to the use of any proper-sizedfishes that can be obtained in reason-able quantity including a wide varietyof tropical reef fishes such as juvenilemullets, Mugilidae; goatfishes, Mul-lidae; cardinalfishes, Apogonidae;damselfishes, Pomacentridae; silver-side, Atherinidae; snapper, Lutjanidae;mosquitofish, Poeciliidae; rabbitfish,Siganidae; etc.

Baitfish acceptability is determinedby three factors: supply, which isdiscussed in a separate section of this

report, mortality. and effectiveness.Live bait is subject to continuousloss from the time it is obtained tothe time that it is used for fishing.Strong bait, that is bait that survivescapture and holding well, is in greatdemand. Studies of factors affectingmortality have been made by Baldwin,Struhsaker, and Akiyama (197 ) ,and Anonymous (1971). Bait mortalityis a complex problem and needs muchadditional work, particularly in con-nection with long distance transportand holding of large quantities of bait.

Effectiveness, that is the produc-

tion of tuna per quantity of bait, isdifficult to quantify owing to lackof good statistics on bait usage. FromTable I it is apparent that there isa wide range of effectiveness expressedin kilogram bait per metric ton oftuna produced. The smaller the ratiothe more effective the bait. Thesemeasures of effectiveness are sub-ject to several biasing errors that re-sult in an overestimate of the baitneeded. The largest error is due tothe use of total bait caught ratherthan bait used in fishing. Thus mor-tality is included in these estimates.


3/12

Also included is bait dumped whenfishing is completed.

Sources of error that affect thevariance of the estimates are the sizeof the tuna fished, more bait beingrequired to take a ton of small tuna,the reporting of bait catches by thebucket or scoop, the constancy ofwhich is questionable, and the com-plex relation between bait mortalityand time spent looking for fish. Thelatter may account in part for theincrease in effectiveness in the easternPacific fishery after 1960 when thebigger boats dropped out of the fisheryleaving as the principal users of baitthe smaller boats that perhaps didnot spend as much time scoutingfor tuna.BAIT CATCHING METHODS

Baitfishes are caught by severaltypes of gear, the most common beingthe bait seine. The details of this typeof gear and operation vary fromlocality to locality. In Hawaii the so-called day net, a round-haul net forshallow water that lacks wings, bag,or purse line, is used. The dimensionsfor a typical day net are 175 by 4 mconstructed of 4.8 mm stretched meshwebbing (Figure I ) . The main baitspecies taken is the nehu, an anchovy,Sto lephorus purpu reus , which is quitesmall and requires a small-meshednet. Another common bait net, usedchiefly in the eastern Pacific, is the

lampara, which has wings and a bagsection, is deeper, and can be used inwaters where the leadline does notnecessarily maintain contact with thebottom. Details of the operationusing this gear are given by Scofield(1951) and Du Plessis (1959).

For baiting in deep water, the purseseine is effective, being superior tothe lampara but requiring more man-power. For shallow water areas wherethe bottom is too rough to drag orwalk the leadline of the net, thedrive net is used (Figure 2) .

'T he 'drive-in-net' fishing methodis said to have been developed inthe Ryukyu Islands (Shapiro, 1949)to catch shoaling fishes in coral reefareas. Divers, sometimes carryingfish-chasing devices, drive the fishschool into a net set strategicallyto block the path of the fish. Assoon as the fish are driven into thenet, the net is lifted to the surface.This method has long been usedfor catching mainly the Apogonidaeand Caesionidae. The size and de-sign of the net differ according tothe fish to be captured. The netusually consists of a bunt and twowings when catching larger andfaster swimming fishes such as adultCaesio, flyingfish, and garfish. Onlythe bunt of the net or a blanket netis used for catching apogonids orother slower swimming fishes orjuvenile fishes. The drive-in net isused to capture apogonids earlyin the morning by taking advan-tage of their nocturnal habit. Thebait fishermen cover a reef withthe net before sunset. The fish are

found hiding in crevices. The netis allowed to remain overnight.The opening over the crevice inwhich the fish are hiding is keptopen in order to enable the fish tomove out at night. The fishermencatch the baitfish early in the morn-ing by driving the fish into thenet before the fish can return totheir hiding places.'The fishermen also catch theapogonids during the day by in-serting tree leaves into crevicesand scaring them out. Some apo-gonids are observed during theday with other baitfish and arecaught along with them. The redscads (Caes io) and 'blue bait' arecaught during the day." Isa (1972).

A second type of baiting operationis night baiting, commonly used incoral-island areas. In this operationa strong underwater light, 750-1,500w, is submerged to as deep as 20 mbelow the surface and allowed. toremain until a quantity of bait hasbeen attracted. The light then is slowlydrawn up toward the surface neara net suspended vertically in thewater. The net typically is of 6.4 mmmesh and nearly square, being about25 m on a side. Once the light andbait are at the surface, the net israised under the bait (Figure 3). Fordetails of this method see June (195 I ) .

Catching bait for tuna fishing isdependent primarily on the avail-ability of quantities of bait and noton the lack of a suitable method oftaking them; i.e., the methodology


4/12

has been well worked out and usuallypresents a minor problem to a baitboat. However, there are some ex-ceptions. These include the introduk-tion of, or the learning of, methodssuited for certain areas by fishermenfrom other areas. For example, theOkinawan live-bait fishermen are gen-erally believed to be the best or mostknowledgeable for operating in coralisland areas where they manage tofind and take bait when fishermenfrom Japan or the United States wouldfail. In part their success lies in the useof wall nets (ha, 1972) suspended nearcoral heads or close to drop-offs.Also, they are adept at the swim-inmethod of bait catching ( ; b i d . ) .Evenwhen more desirable baits are absentthey are able to take small quantitiesof bait by tearing apart coral heads.This practice is not to be recom-mended but is used at times. Species

F i g u n 2 A t c h i n q b.H with a drlve-in net.

taken in this manner include smalldamselfish and cardinalfish.

A source of bait that might be usedif the catching techniques could bedeveloped occurs offshore whereschools of clupeoids and carangidsexist in considerable abundance andsometimes come to a light. Also itis frequently observed that floatingobjects attract quantities of smallfish, and i t may be that natural or arti-ficial floating logs together witha lampara or purse seine might beused to obtain bait. I t may be pos-sible to develop a night-light, lift-net operation or a deepwater lamparaor seine operation that could providesupplies of offshore bait at certaintimes in certain places. Night baitingusing deeply submerged lights eitherinshore or offshore is undergoingfurther refinement in some areas. Inaddition, the use of set nets, or weirs,

may hold promise in areas where thebait species are migratory either alongthe shore or inshore-offshore.HOLDING AND TRANSPORTOF THE BAIT

Once the bait is in the net, it mustbe transferred to holding tanks orwells (eastern Pacific and Japan,Figure 4) or boxes (central-westernPacific) aboard the vessel or into re-ceivers if it is not to be loaded onthe vessel immediately. When thebaitfishes are hardy, as is the casewith most of those taken in the easternPacific, the transfer from the net toholding tanks or receiver is accom-plished with a dip net or scoop. Inthe 1 9 5 0 s at the height of the baitboat era in the eastern Pacific a scoopheld about 4 kg of bait and was thecommon unit of measure used. Today

4


5/12

with the trend towards smaller baitboats the scoops are smaller and hold1-2 kg. Elsewhere, where the baitspecies are more delicate and sub-ject to high mortality by abrasionand bruising (the tropical clupeiodswith their highly deciduous scales areparticularly susceptible). the transferis made by the use of buckets. Theseare generally of seamless stainlesssteel with a capacity of about 15 liters.The bucket keeps the fish mixed withsufficient water to reduce scale lossand bruising. In areas such as Hawaiiand Japan, the bucket is the commonunit of measure for baitfishes. Thebucket holds on the average 3.5 kgof bait in Hawaii and 5.5 kg of baitin Japan although, as with the scoop,the actual amount is quite variable.Injury and shock during transferof the bait into the holding tanks orreceivers account for most of themortalities. Losses can be very highif the bait has been handled carelessly.Bucketing appears to reduce mortalityas does increasing the amount ofoxygen in the holding tanks, reducingthe temperature, lowering salinity,and avoiding crowding and undueexcitement of the bait until it has hada chance to acclimate to its new en-vironment. For discussion of waysof reducing the rate of mortality as-sociated with the Hawaiian live-baitfish nehu, S. p urp ureus , see Baldwinet al. (1971). In addition, methods ofavoiding brailing or bucketing baitfrom the net to the wells could standcloser examination. For example,the swim-aboard technique used bythe west coast bait haulers might beadapted to commercial baitfishingoperations. This is a method wherethe fish enter the well through a gateat the waterline of the vessel therebyavoiding the brailing operation.

Some work has been done in trans-ferring bait by means of pumps (Bald-win, 1969). Whether or not this

Flgure 3 . 4 l g h t baiting with a Hawaiien-typ. iS net.

A 7

I '> I IAIJ

Figure 4.-Japanese belt boot wells ahowingthe perloretori inflow plpe, overflow, and A - A , CROSS SECTION"b ilge"-pipe fo r cmt inuws remova l of deedbait. (From Miho Shlpbuiiding Co., 1966.)

5


6/12

PI-. S.-R.htIon betun W *W l.mpra-en and b i t m01(a11y on a (11 Irarrllngfrom Jg.n IO th o southom water goundo.(From Anonymous, 1871.)

would result in reduced mortality isopen to investigation. It certainlywould speed up the loading operation.

In holding baitfish aboard vessels,there are a number of factors thatare important. First is the supply ofwater. In the central and westernPacific with the older Japanese, Ha-waiian, and Okinawan style vessels,water comes in through holes in theboat at the bottom of the boxes, cir-culation being assured either by themotion of the vessel through the wateror the rolling of the vessel by waveaction. The amount of oxygenatedwater supplied in this manner is ade-quate for small quantities of baitheld for short periods. With the ves-sels of the eastern Pacific and thenewer Japanese pole-and-line vesselsthat carry. large quanti ties of bait overgreat distances, circulating seawateris supplied by pumps to the wells.As a general rule, a turnover of thewater in the wells 5 to I O times anhour is desirable. Typically, a iO-m3well would have a water exchangeat the rate of about 1,500 liters perminute. The carrying capacity of awell with forced circulation variesfrom I O kg of baitfish per cubic meterof water to as high as 50 kg per cubicmeter. Capacity is affected by watertemperature (Figure 51, the speciesand condition of the bait, and the seastate, high mortality of the baitfishoccurring during rough weather. Prop-er lighting in the wells also is animportant factor in reducing mortality.

If the bait is to be maintained foran extended period of time it is neces-sary to feed it . This is a problemparticularly in the eastern and westernPacific where large bait boats willtry to keep bait aboard for severalweeks. Foods used vary from choppedfish to bread and meal and preparedfish chows.

It is important that the bait berested before the tr ip begins. This isfrequently done by holding the bait

~.

I -197L M V 25I zP

NO. OF DAYS F O L K M I f f i D E M U R E

in receivers or in the tanks for severaldays prior to departure from the bait-ing grounds. In the Japanese southernwater fishery, for example, wherethe vessels transport their bait fromJapan to the tropical western Pacific,the bait is rested in receivers forseveral weeks prior to departure.

Another source of mortality thatcan present a problem in the centraland western Pacific occurs when thebait comprises a mixture of species.If the mixture involves larger pred-atory fish together with the smallerdesirable bait species, the larger pred-ators will either eat or frighten thebait resulting in a high mortality.Also not uncommon are instanceswhere juvenile lae, Sco rnb cro i d essa nc t i -p e t r i , a small carangid, is takenwith the bait and causes high orcomplete mortality by biting the scalesoff the baitfish (Struhsaker, Baldwin,and Murphy, unpublished'). Develop-ment of satisfactory separators toseparate the desirable from the un-desirable species needs investigation.For chumming, the baitfish arecrowded with a small net or "crowder"

Struhsaker. J. W.. W. J. Baldwin. and G. I.Mur-phy. n.d. Environmental factors affecting stressand mortality of the Hawaiian anchovy (S to l e -phorus p u p u re u s ) in captivity. n.p. Completionreport prepared lor National Marine FisheriesService under Commercial Fisheries Researchand Development Act (P.L. 88-309), roject H-10-R. Hawaii Institute of Marine Biology, Universityof Hawaii . Keneohe, HI 96744.

so that they can' be easily brailed out.With some species this causes anextreme fright reaction and high andrapid mortality. The sprats, Sp ra t e l -l o i d e s sp., called piha in Hawaii, areplentiful and ubiquitous throughoutthe central and western Pacific. How-ever, these are very delicate baitfishthat die within a few hours of load-ing into the well. In part the mor-tality occurs during crowding forchumming and if this mortality couldbe alleviated, these plentiful fisheswould represent a major increase inbait supply throughout the islandareas.

A so far neglected area for investi-gation is the use of drugs to lessenthe fright reacticn and metabolic re-quirements of baitfishes. For example,the use of anesthetics and tranquilizersin the transport of trout, salmon,and other freshwater fish is more orless routine, whereas this is not thecase in the transport and holding ofmarine baitfishes.

FISHING OPERATIONS-CHUMMINGBaitfishing for tunas depends upon

locating surface tuna schools. Oncethe school is located, a portion ofthe bait in the well is crowded with

6


7/12

a net into a reduced area where i tcan be dipped out with a dip net.Small amounts of bait are tossedinto the water in such a way as tobring the tuna to the boat. Chummingtechniques vary somewhat with areaand with the type and quantity ofbait available. Various tricks are usedto alter the behavior of the bait tomake it attractive t o the tunas. A goodchummer has techniques that producetuna at a rate that an inexperiencedchummer cannot match.

The handling of the boat varieswith area, too. In the eastern Pacificand in Hawaii the vessel moves slowlyahead and fishing is conducted fromthe stern. In the Japanese- and Oki-nawan-type fishing the vessel isstopped dead in the water and fish-ing is conducted along one entireside from the stern to the end of theextended bowsprit. The crewmenaboard Japanese- and Okinawan-styleboats generally number 3 to 5 times

SUPPLYThe major problem in baitfishing

is obtaining a sufficient and depend-able supply of bait. Discussed in thissection will be natural bait, rearingof bait, transport of bait, and arti-ficial bait. The introduction and estab-lishment of nonendemic bait specieswill not be considered. Pertinent toany discussion of supply is the ques-tion of the value of the bait to thefishermen. How much is it worth tothe fishing operation to have baitaboard? Obviously without bait therecan be no production of tuna andtherefore no income. A number ofstudies have been undertaken in orderto assign some value to the bait. Themethodology used includes the em-pirical approach, the examinationof what fishermen are willing to payfor bait available for sale; the oppor-tunity cost approach, what catchingbait costs the vessel in terms of lostfishing time; and the marginal product

Under these circumstances it is pos-sible to estimate the cost of catchingthe bait based on the time lost tofishing. For example, in Hawaii,studies suggest that between 25% and30% of the time available for fishingis spent searching for and catchingbait. This puts the cost per bucketof bait between $1 2 and $ 3 0 ($3.50and $ 8 . 5 0 per kg ) (Brock and Takata,1955; Shang and Iversen, 1971).Similarly studies in Hawaii based onthe production function method sug-gest that the value of a bucket of baitis as high as $80 ( $ 2 3 per kg) to thevessel (Elliott, Keala, and Matsuzaki,unpublished*). Because of the widerange among these figures, for plan-ning purposes a good estimate is $10-$20 per bucket ($3-$6 per kg). It isquestionable whether refining thesec a t estimates is worthwhile at thispoint since the sociological problemof convincing fishermen to purchasebait appears to be greater than con-vincing them that the bait is worththe men aboard a Hawaiian- or west approach, a method that gives a maxi- so many dollars per bucket based on

coast-style bait boat. Production mum value for bait. their fishing operation. Past experi-figures per day's fishing between the Live bait is sold to commercial ments for example whereby the Statetwo methods are generally compar- fishing operations in Japan and to a of Hawaii raised tilapia, Tilapia r m s -able, however. I t is believed that the lesser degree on the west coast of surribica, for bait (Brock and Takata,use of bait by the eastern Pacific the United States. In the case of the 1955; Shomura, 1964) and made i tboats is more profligate than by theHawaiian or oriental boats and in-deed there appears to be some truthto this belief (Table I ) . However, thenumber of baitfishes thrown per schoolis probably near equal owing to thedifferent size of the fish used. Gooddata ar e not available for the Japanese

former, the vessels pay about $10per bucket ($ 2 per kg) at the baitseller's receiver. The bait then has tobe transported to the fishing groundsand may undergo considerable mor-tality, typically20% to 30% butattimesmuch higher. On the west coast ofthe United States the selling price

available to the vessels at a nominalprice failed, not because the price ofthe bait was too high but becausethe fishermen felt that the bait theycould catch was superior and free.Since then their attitude towards thepurchase of bait has changed to agreat degree.

southern water fishing vessels. of bait may be as low a $ 2 per scoop($0.50 per kg), the amount of baitin the scoop being less than the Japa-

use of a water spray system (Yuen, nese bucket. Again, the buyer has1969) throughout the central and to accept the mortality during trans- The location of abundant naturalwestern Pacific is absent or very port from the bait seller to the fishing baits (Table 2 and Figure 6 ) is ofuncommon in the eastern Pacific. grounds. During a recent experiment prime concern for the expansion ofWhether or not the vessels would where northern anchovy, Engruul is bait fisheries in the central and westernbe more productive in the eastern / m r d u x , was brought in from Cali- Pacific. The location of bait usuallyPacific if water sprays were used is fornia to Hawaii, the vessels were depends upon bait surveys, whichnot known, but comparison between willing to pay $20 per bucket.fishing with and without the water With the exception of Japan it Elliott. D. P ., 6. A . Keala. and C. Matsuzaki. n.d.Estimation of demand for live bail to be used inspray shows that i t indeed does affect appears t O be more traditional for each theskipjackfish ing ndustry.21 p. [Technical reportthe catch rate in Hawaiian waters vessel to carry its own bait net and Subm ' t t ed lo Fisher ies Cente r . Na-tional Marine Fisheries Service. N O A A . t lonolulu.( i b i d ). bait skiff and to catch its own bait. til 96812.1

It is interesting to note that the Natural Bait SUpplieS

7


8/12

Table 2.-Avallabllltv of ball lor live-bail fiehim In the P.clfic and IndianOcmna.Areal Kinds of baitfish Commercial landings Used for live bait Potential

1 Indian OceanMinicoy. Laccadive Is.

2 Southeast Asia3 J apan: Northeast

CentralSouthwest4 Formosa25 South Korea36 Philippine IS .7 Marianas

Anchovy, sardine. herringReef fishes-apogons. damsels, etcAnchovy, sardine. herringAnchovy, Engraul ts lapontcus

dodoAnchovyAnchovyAnchovyRabbitfish. etc

>100,000 metric tonsLimited amount

>40,000metric tons7,299 tons73,541 tons144.508 tons

??

20,000 metric tons7

7

Yes?

1,970 tons10.857 tons11,200tons7

???

Very goodLimited. small lishery

Very goodExcellentExcellemExcellent

??

Very goodVery poor (highlyseasonal)

GoodWestern Carolines Anchovy, sardine, silverside,round herring, etc.do

7 Est. >100.000 buckets

9 Eastern Carolines 7 ? Poor, OK lor smallscale operation?

GoodAnchovy, sardineAnchovy, sardine, silversidemackerel. etc.SardineSardineGoatfish. mullet. etc.Sardine. silverside, roundherring, etc.Sardine, anchovy, mackerel.etc.Mackerels. round herring. etc.Goatfish. mullet. round herringSardineGoatfish, mullet, etc.Anchovy. silverside. roundherring, etc.Silverside, mullet, goatfish. etcAnchovy, anchoveta. sardine

??

?Experimental

10 New Guinea'11 Fij i

Yes??

Experimental

??

PoorGood

12 Solomon I s .$13 Gilbert Is.614 Phoenix'ls.15 Marshall Is.

16 Samoa ? Experimental Poor

17 Society Is.18 Tuamotu Archipelago19 Marquesas Is .20 Line Islands21 Hawaii

ExperimentalExperimentalExperimentalExperimental

ca 35,000 buckets(130 metric tons)Experimental

4,000,000 scoops(14.500 metric tons)

PoorPoor

Good (seasonal)PoorGood

PoorExcellent

Leeward Is22 Eastern Pacific:California to Panama

7

>200,000 metric tons

2 3 Southeastern Pacific: AnchovetaPanama to Chile Es t. 10,000,000 6(10,000coops Very goodmetric tons (2.200 metric tons)1 See Figure 6.2 The J apanese mention Formosa as a possible baitfish source.3 The J apanese mention Pusan as having a good supply of strong bait.

4 The J apanese operate several boats i n this area.5 The Japanese have 6 boats in this area; will increase to 11.6 The J apanese have been operating in the area.

may give misleading results unlessthey extend over a long time span.Survey methods include full-scalecatching operations, diver surveys,interviews with inhabitants, aircraft,beachwalking, etc. Examples of re-cent bait surveys are [Japan.] Fish-eries Agency (l969), Hida (1971),Wilson (197 ) , and Kearney, Lewis,and Smith (1972). Problems with

surveys include the seasonal or cyclicchanges in abundance of specieswhereby certain areas that may haveplentiful quantities of bait one day,may have none the next. Too, theamount of bait may vary from yearto year or over a many-year period.Even when baitfishes are located inquantity, the question still arises asto the amount of bait that can be

taken. Few if any population dynam-ics studies have been done on tropi-cal bait species. Perhaps the mostintensive involved the anchoveta inCentral America (Bayliff, 1966), anda study of the tropical anchovies inPalau by Garth I . Murphy (Univer-sity of Hawaii, Honolulu, HI 96822)is still in progress. Most of thesefisheries appear to be capable of tol-

8


9/12

erating high fishing mortality; how-ever, better information is needed be-fore it will be possible to managethese resources. For much of thePacific, however, supplies of naturalbaits are less than required for maxi-mum tuna production.Aquaculture

Aquaculture is a possibility for sup-plying baitfishes in areas where naturalbaits are limited or lacking. The prob-lems here are threefold, namelyrearing a baitfish that is an accept-able bait for tuna, producing it at acompetitive cost and producing itin sufficient quantity to support anumber of tuna boats. The provisionalbait price developed above, about $1 5per Hawaiian bucket ($4.50 er kg),is sufficiently high that aquacultureshould be an economically accept-able solution.Mass rearing probably presentsminimal difficulties because of a fairlyextensive background in the produc-tion of fish through aquaculture.

Acceptability as discussed pre-viously covers both mortality and ef-fectiveness. With the Hawaiian nehu,mortality typically runs 25% per day inthe baitwell, suggesting that a hardierbait produced by aquaculture thatsuffered only a 5 % mortality rate couldbe 20% less effective in the production

of tuna and yet be acceptable. Simi-larly, a less effective bait that couldbe produced at lower cost than nehumight, from the standpoint of econom-ics, be an acceptable substitute bait.

In selecting a species for aquacul-ture, consideration has to be giventQ those factors affecting its accept-ability, that is, hardiness and effec-tiveness, and those factors affectingits production, for example, canspawning be controlled? Are there dif-ficulties in production of the young?Does it grow to an unacceptablesize, etc.? Work has been done withseveral species-tilapia (King andWilson, 1957), threadfin shad (Iver-sen, 197 I ) , commercial sharpnosedmolly (Herrick, unpublished3). Otherspecies considered or tested includecarp, fingerling catfish, juvenile mul-let and goatfish, and golden shiner.The difficulties lie in finding speciesthat can be raised in quantity and indevising a quantitative measure oftheir acceptability. For screening, amethod that appears practical at pres-ent, since the characteristics of agood baitfish are poorly defined, isa series of field tests whereby sufficientquantities of bait are used in sea trialsto determine its relative acceptability,3 Herrick, S. F.. Jr. 1972. Economic analysis ofcommercial molly (Poecilia sphenops) baitfishaquaculture. 11 p . and attachments. Hawaii Insti;lu te of Marine Biology, University of Hawaii,Kaneohe. HI 96744.

9

that is, its mortality and effectiveness.For work in Hawaii and using nehuas a reference bait from Table I ,it would appear that 30 kg of nehuwill produce a metric ton of tuna.Screening experiments should includealternate uses of nehu and the sub-ject bait over an extended period oftime. The varian4e of catch rates fortuna boats is high and screening testsof the proper sensitivity cannot beconducted with small amounts of bait.In order to give an indication of ef-fectiveness 200 buckets or enoughfor approximately 5 days of fishingis suggested. This will provide aninitial indication as to the desirabilityof continuing with the species orabandoning it . The difficulty inmaking such a judgment is pointedout in our experience with thread-fin shad whereby the results obtainedduring I year with shad aboard RVChur les H. Gilbert and during anothertrial using a commercial vessel gavedifferent answers.

The desirability of using a salt-water versus a freshwater or a eury-haline species needs considerationsince production in fresh water maypresent fewer problems than in saltwater, the methods being better devel-oped, and there are many freshwaterspecies that appear to possess thecharacteristics desirable and neces-sary to be good tuna bait. However,


10/12


11/12

(Opposite) Kawakawa an d bsl1li.h in tsnk. TankIs wed for studles ol k h s v l o r ol fishes. in-cludlng U M S .in many island areas, sufficient freshwater for mass rearing is lacking andculture would have to be conductedin salt or brackish water. Also, therewould be difficulty in maintainingfresh water in the baitwells aboardthe vessel.Transport

Another approach to bait supplyis the transport of quantities of baitfrom an area where it is plentifulinto the area of the fishery. In effectthis is done in both the eastern andwestern Pacific by larger bait boatsthat bait in coastal areas and thencarry the bait 10 the fishing grounds.The next step in this process is totransport the bait aboard a bait carrierto an area in the fishing groundswhere it can be sold to the fishingvessels. This approach has not beenexamined in detail but it appears thatusing a $4.50 per kg bait price thismay be feasible. This figure is basedon data from the Hawaii fishery wherebait usage is low owing to the large,7 kg and up, skipjack tuna consti tutingthe bulk of the season fish. in areaswhere the average weight of the skip-

jack tuna is less the value of thebait may be expected to drop. There-fore, the profitability depends uponthe amount of bait that can be carriedin a given volume of water, theanticipated mortality during trans-port and holding at the final desti-nation, and the value of the bait deter-mined by its effectiveness. To evaluatesuch operations it is necessary to lookboth at the economics of shippingand the fishery, and at mortalityduring capture, loading, transport,unloading, and holding. Experimentsconducted by the Honolulu Labora-tory in transporting northern anchovyfrom California to Hawaii suggestthat mortality in shipment may beacceptable. These shipments weremade using commercial fishing ves-sels, which took approximately I Odays to make the crossing. Commer-cial shipping lines can make the cross-ing in about 4 days. The advent ofroll-on, roll-off service between themainland and Hawaii, for example,suggests that transport of anchovymight be practical aboard these ves-sels. Similarly the advent of LASH(lighter aboard ship) service to FrenchPolynesia and American Samoa sug-gests that i t might be feasible to shipbait from California, Latin America,or Australia to these areas. See Figure

NATURAL BAIT Lou\L 8917 W P R Y(LOCAL W DISTANT1 I 1

FIND DETERUlHEI W E Y EFFECTVENESStMSTRlBUIXM C4TWING

DETERUNEEFFECTVENSSECIESSELECTW41STESEL EC T W fWJ-ECONOMCS

7 for a diagrammatic summary of thepreceding discussion.Artif icial Bait

The use of dead or inanimate sub-stances and new live baits to replaceconventional bait for surface tunafishing should be considered. Earlyattempts such as those conducted atthe Honolulu Laboratory in the 1950s(Tester, Yuen, and Takata, 1954)were unsuccessful, but these studiescannot be regarded as exhaustive andfurther experimentation should be sup-ported. It is possible that dead bait-fish or objects resembling baitfishcould be made to sink and rise ormove in the water so as to resemblea live baitfish. Incorporation of ascent into the objects or the use ofdead bait for this purpose might serveto supplement live bait or even toreplace it.

New BaitsThe use of animals other than fish

for bait has been suggested. Shrimpor large brine shrimp might prove tobe an acceptable bait. Similarly crus-tacea that can be held in suspendedanimation or in the egg for extendedperiods of time might prove to be avaluable adjunct to live-bait fishingfor tuna. The advantage here is thatthese types of animals can be pro-duced almost upon demand and inlarge quantities from a small initialvolume. Studies along these linesappear worthy of support althoughthe probability of success is less likelythan with aquaculture or transport.SUMMARY

The use of live bait to catch tunasaccounts for over 20% of the worldtuna production. This method is es-pecially suited for areas where tunaschools cannot be caught effectivelyusing more efficient. that is, capitalintensive, gear such as the purse seine.

Dependable supplies of acceptable11


12/12

live bait are the key to successfulbaitfishing. Acceptable bait speciesare those that can be held and trans-ported with low mortality and areeffective i n catching tunas, that is,the ratio of bait used to tuna caughtis minimal.

Dependable supplies of naturalbait do not occur in the newest tunafishing grounds in the tropical Pacific.Ways of providing a supply includeaquaculture, importation of bait fromother areas, and development of arti-ficial baits. All of these alternativesare subject to the economic constraintof an estimated $4.50 per kg valueof baitfish delivered to the fishingvessel, and require varying amountsof research before they can be con-sidered feasible. Also needed are betterreporting statistics from presentlyused baiting grounds and the con-tinued search for new supplies ofnatural bait.LITERATURE CITEDAnonymous. 197 1. Skipjack fishery devel-opment . . . bait problems. From 1971edition of the Skipjack-Tuna Yearbook(Katsuo-Maguro Nenkan), Suisan Shin-choosha Tokyo, Japan p. 84-90 95-98.(Translited by T. Oth~, 1972, 15 p.;available NOAA, Natl. Mar. Fish. Serv.,Southwest Fish. Cent., Honolulu, HI968 12.Baldwin, W. J. 1969, A report on the recentfish pump experiments with nehu andiao. Univ. Hawaii, Hawaii Inst. Mar.Biol., 20 p., 13 figs.Baldwin, W. J., J. W. Struhsaker, andG. S. Akiyama. 1971. Longer life fornehu. [In Engl. and Jap.] Sea Grant Ext.Booklet, 24 p.Bayliff, W. H. 1966. Population dynamicsof the anchoveta, Cefengraulis mysfice-

Ius, in the Gulf of Panama, as determinedby tagging experiments. Bull. Inter-Am.Trop . Tuna Comm. 11: 173-352.Brock, V. E., and M. Takata. 1955. Con-tribution to the problems of bait fishcapture and mortality together with ex-eriments in the use of-tilapia as livegait. Territory of Hawaii, IndustrialResearch Advisory Council Grant 49,Final Report, 39 p.Congress of Micronesia. 1972. Report o nVan Camp fisheries operations in PalauDistrict IDrewared bv Michael A. Whitefor] Fourth- Congiess of Micronesia,Second Regular Session, 1972! 120 ,p .Du Plessis, C,. G. 1959. Fishing withSouth African pursed lampara. -I n H .Kristjonsson (editor), Modern fishinggear of the world, p. 391-393. FishingNews (Books) Ltd., Lond.Food and Agricultural Organization ofthe United Nations. 1971. Catch andlandings, 1970. Yearbook of fisherystatistics. FA0 (Food Agric. Organ.U.N.) Vol. 30, 476 p.

Godsil, H. C. 1931. The relative efficiencyof the semipurse seine compared withthe round haul net. Calif. Fish Game17: 52-5 3.Green,, R. E., W. F. Perrin, and B. P.Petrich. 1971. The American tuna purseseine fisher In H. Kristjonsson (editor),Modern fiskng gear of the world, 3:182-194. Fishing News (Books) Ltd., Lond.Hawaii Division of Fish and Game, andBumble Bee Seafoods. 1970. Purse seinefishery for skipjack tuna (aku) in Hawai-ian waters - summer 1970. Hawaii Div.Fish Game and Bumble Bee Seafoods,Div. Castle and Cooke, Inc., Honolulu,33 p.Hida, T. S. 1971. Baitfish scouting in theTrust Territory. Commer. Fish. Rev.33( 11-12):31-33:Inter-American Tropical Tuna Commis-sion. 1956. Annual report for the year1955. [In Engl. and Span.] Inter-Am.Trop. Tuna Comm., La Jolla, 95 p.1960. Annual report for theyear 1955. [In End . and Span.] Inter-Am.Trop. TunaComm., 156 p.. 1966. Annual report of theInter-American Tropical Tuna Commis-sion, 1965. [In Engl. and Span.] Inter-Am.Trop. Tuna Comm.. La Jolla, 106 p.. 1970. Annual report of theInter-American Tropical Tuna Commis-sion, 1969. [In EngI. and Span.] Inte r-Am.Trop. TU M Comm., La Jolla, 117 p.Isa, J. 1972. The skipjack fishery in. theR ukyu Islands. InK. Sugawara (edtor),T i Kuroshio 11, Proceedin of theSecond Symposium on the fesults ofthe Cooperative Study of the Kuroshioand AQiacent Regions, Tokyo, September28-October 1. 1970, p. 385-410. SaikonPubl. Co., Ltd., Tokyo.Iversen, R. T. B. 1971. Use of threadfinshad, Dorosoma perenense, as live baitduri n experimental ole-and-line fishingfor seipjack tuna, ~ a f s u w o n u spelamis,in Hawaii. U.S. Dep. Commer., NOAATech. Rep. NMFS SSRF 641. 10 p.Iwasaki, Y. 1970. Recent status of pole-and-line fishing in southern waters. [InJap.] Abstract 1141). p. 8-12 of symposiumpapers presented at the Japanese TunaFishery Research Conference, February1970, Far Seas Fisheries Research Lab-oratory Shimizu, Japan. (Translatedby T. ihsu, 1970, 8 p.; available NOAA,Natl. Mar. Fish. Serv., Southwest Fish.Cent., Honolulu, HI 96812.)Japanese Fisheries Agency. 1969. Reporton fishery survey in the Bismarck Sea -Solomon Sea areas by the Shunyo-Maru,October-December 1968. [In Jap., Engl.synop.] Far Seas Fish. Res. Lab., S Ser.1, 170 p.Japanese Ministry of Agriculture andForestry, Statistics and Survey Division.1970. Fisheries statistics of Japan, 1968.[In Jap.] Tokyo, 268 p.

June, F. C. 1951. Preliminary fisheriessurvey of the Hawaiian-line Islandsarea. Part 111 - The live-bait skipjackfishery of the Hawaiian Islands. Commer.Fish. Rev. 13(2):1-18.Kearney R. E. A. D. Lewis, and B. R.Smith. 1972. Cruise report Tagula 71-1.Survey of skipjack tuna and bait re-sources in Papua New Guinea waters.Dep. Agric., Stock Fish., Port Moresby.Res. Bull. 8, 145 p.King, J. E., and P. T. Wilson. 1957.Studies on tilapia as skipjack bait. U.S.Fish Wildl. Serv., Spec. Sci. Rep. Fish.225, 8 p.McNeely, R. L. 1961. Purse seine revolu-tion in tuna fishing. Pac. Fisherman59( 7): 27-58.Miho Shipbuilding Company. 1966. Thelive-bait tanks on skipjack vessels. J.Fish. Boat Assoc. Jap. 144:168-171.(Translated by T. Otsu and edited byH. Nakamura 1968, 8 p.; availableNOAA, Natl. Mar. Fish. Serv., South-west Fish. Cent., Honolulu, HI 96812.)Scofield, W. L. lY51., Purse. seines andother roundhaul nets in California. Calif.Dep. Fish Game, Fish Bull. 81, 83 p.Shang, Y. C., and R. T. B. Iversen. 1971.The production of threadfin shad aslive bait for Hawaiisskipjack tuna fishery:An economic feasibility study. Univ.Hawaii, Econ. Res. Cent., 42 p.Shapiro, S. 1950. The Japanese long-linefishery for tunas. Commer. Fish. Rev.12 (4): 1-26.Shomura, R. S . 1964. Effectiveness oftilapia as live bait for skipjack tuna fish-ing. Trans. Am. Fish. Soc. 3:291-294.Tester A. L. H. Yuen, and M. Takata.1954. Reaction of tuna to stimuli,, 1953.U.S. Fish Wildl. Serv., Spec. Sci. Rep.Fish. 134, 33 p.Webb B. F. 1972. Report o n a tuna pole-fishing and live bait venture, H ok oMaru 15 : February 8 to March 24 1972.Sect. 1: General introduction; Sect. 2:Bait fishing. N. Z. Minist. Agric. Fish.,Fish. Tech. Re 112, 61 p.1973. Report on the investi-gations of the Lloret Lopes: 8 Januaryto April 1.970. Sect. 4: Polefishing andtrolling method; Sect. 5: Longliningmethod. N. Z. Minist. Agric. Fish., Fish.Tech. ReD. 105. 38 w.Wilson P. T. 1971. Truk live-bait survey.U.S. Dep. Commer., NOAA Tech. Rep.NMFSCIRC 353, 10 p.Yuen, H. S. H . 1969. Response of skip-jack tuna (K afs u w on u s pelamis) to ex -perimental changes in pole-and-line fishingoperations. I n A. Ben-Tuvia and W.Dickson (editors), Proceedings of theFA0 conference on fish behaviour inrelation to fishing techniques and tactics,p. 607-618. FA 0 (Food Agric. Organ.U.N.) Fish. Rep. 62.

iZ G P O 799-420

MF R Paper 1060 . From Marine Fisheries Review, Vol. 3 6 , N o . 5 .Copies of this paper, in limited numbers, are available From0 8 3 , Technical Information Division. Environmental Science Infor-mation Center, N O A A , Washington, DC 20235.

12

bait species effectiveness

Documents