Specified Skills
Educational Textbook for the Fishing Industry Skills Proficiency Test
(Fishing)(Line Fishing)

Japan Fisheries Association(First Edition: December 2019)Table of Contents

Pole-and-Line Bonito Fishing

1. Fishing Grounds ····················································································· 2
2. Caught Fish ··························································································· 2
3. Fishing Tools·························································································· 2
4. Operations ····························································································· 3
5. Processing Catch ···················································································· 5

Squid fishing

1. Main Types Targeted ··············································································· 8
2. Squid Fishing Techniques ········································································ 8
3. Operation Procedures and Content ························································· 12
4. Packing and Unloading ········································································· 13

Tuna Longline Fishing

1. Overview ····························································································· 15
2. Targeted Fish ······················································································· 15
3. Main Fish Bycatch ················································································ 16
4. Bait Used ···························································································· 16
5. Structure of Fishing Tools ······································································ 16
6. Fishing Devices ···················································································· 18
7. Main Line Storage Devices····································································· 19
8. Line Waiter·························································································· 20
9. Line Hoisting Work ··············································································· 20
10. Fish Processing Methods······································································ 20

Pole-and-Line Bonito Fishing11. Fishing Grounds
Fishing grounds for pole-and-line bonito fishing are in the waters near Japan,
the international waters of the Pacific Ocean, and the tropical regions of island
countries.

2. Caught Fish
The main types of fish targeted in pole-and-line bonito fishing are bonito,
albacore tuna, yellowfin tuna, and bigeye tuna. In addition to these species,
dolphins, mackerel tuna, frigate tuna (bullet tuna, auxis thazard thazard),
yellowtail amberjacks, and rainbow runners are also caught.

3. Fishing Tools(1) Fishing Poles, Automatic Fishing Machines
For fishing poles, while bamboo poles are used as well, fiberglass poles are themost common. They range from 2.5m to 4.5m in length depending on the fishinglocation (the height of the side of the ship). Fishing locations closer to the tip of theship use longer poles. Furthermore, longer poles are used for fishing with bait,
while shorter poles are used for fishing with lures.
Fishing

poles

are

preparedbyattaching a main line, a snell, and ahook (Fig. 1). In addition, in order toaddress crew shortages and energy
reductions,"automatic

machines"

which

move

Figure 1: Snell and lurefishingpoles

automatically using hydraulic pressure or electricity, are also utilized for bonito
fishing.
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(2) Fishing Lines
Fishing lines are composed of two different lines: one called a “main line” andone called a “snell.” When using lures, the length of the main line is about 40 cm
shorter than the length of the fishing pole used. A snell of about 20 to 30 cm isattached to the end of the main line in this case.
(3) Fishing Hooks
Fishing hook types differ depending on whether a lure is used or live bait is
attached.
Lures are used in fishing when bonito are actively biting (Fig. 2), and live bait is
attached to a barbed fishing hook (Fig. 3) when there are fewer bites. Lures do nothave barbs, so when bonito caught on the hooks are reeled in, the bonito will detachfrom the hook while in the air.

Figure 2: A fishing hook for lure and ahook with artificial bait

Figure 3: A fishing hookfor fishing with bait

4. Operations(1) Sighting a School of Fish and Commencing Fishing Operations
When a school of fish is sighted, the fishing vessel approaches it at full speed.
Fishing preparations begin when the fishing vessel reaches the school of fish andthe bow of the ship comes into contact with it.
In the time between sighting a school of fish and commencing fishing operations,3

live bait is transferred into a throwing bucket along with seawater, and this bucket
is then inserted into a barrel on the left side of the bow. The fishing location ispredetermined, and bonito are landed from a fishing stand installed on the side or
bow of the boat. Veterans or fishermen with superior technique are usually
positioned on the bow side. As the stations move to the left side and rear, fishermen
are stationed in order of descending skill levels, first intermediates and thenbeginners.
(2) Commencement of Bait-Throwing
Operations
When the fishing vessel arrives at
the fishing grounds, seawater issprinkled using sprinkler systems
extending from the bow of the ship to
Figure 4: Live bait is scattered while
the water sprinkler systems operate

the left side as a means of improving
the movement of the bonito. The crew

member in charge of throwing the bait scoops the live bait into a round net andscatters it onto the sea surface (Fig. 4).

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(3) Fishing
When the bonito start biting in response to thesprinkled water and the scattered lived bait, lures
are used. If they are not biting, fishing is conductedwith live bait attached to a fishing hook. Whenfishing with lures, fish is caught on the hook are
grounded quickly (Fig. 5). Because lures do nothave barbs attached, bonito must be reeled inquickly or they will quickly detach from the hooks
while in the air or above the deck. When the bonito
fall onto the ship, they slide into the fish hold via
a slope. The most important point when catching

Figure 5: When the fish are biting,the crew members spread out along
the central cabin and fish

bonito is reeling them in from directly in front ofyou. If you attempt to reel in a fish when it is swimming horizontally, the fishinghook may become entangled in another person or fishing line and cause an injury,
so be careful.
When fishing with bait, the fishing hook has a barb attached. Accordingly, afish that has been reeled in should not be swung overhead, but instead held
under one's left arm. After removing the hook with your right hand, throw thefish onto the slope behind you, allowing it to slide into the fish hold.

5. Processing Catch(1) Fresh Processing
For near-sea fishing ships that unload fish fresh, the catch must be stored incooled water which is a mixture of seawater and fresh water using a refrigeration5

system in order to maintain the freshness of the fish. The cooling temperaturedepends on the fishing vessel, but ranges from 0 to 2°C.
(2) Unloading
When unloading fresh bonito, each fish is carefully unloaded from the ship byhand. The crew members, wearing raincoats and gloves, enter the fish hold, grab
one or two fish in each hand, line up along the wall from the fish hold to thewharf, and pass the fish out of the boat by hand.

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Squid Fishing7

1. Main Types Targeted
In the area near Japan, the main types of squid caught are the Japanese common
squid, the spear squid, the swordtip squid, and the neon flying squid.

2. Squid Fishing Techniques
Although squid fishing is also conducted during the day, it is mainly carried out
at night. In nighttime operations, lights called fish-luring lights are used to cause
squid to gather around the fishing vessel, and the squid are caught using lurescalled squid jigs.
(1) Parachute Anchors
Squid fishing is carried out with the ship in motion together with the current toavoid having the fishing lines get tangled. For this reason, a parachute anchor(para-anchor) is cast into the sea from the bow of the ship. Inserting a para-anchor
allows the ship to move with the current (Fig. 6).

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Fish-luring
lightsSpankersailPara-anchor rope(length is 1.5x the radius)

Automatic squid
fishing machines

Float
Fish
schooldetector

Water
thermometerTow rope
250 m
maximumlengthTowing rope
80 to 100m

Parachuteanchor
φ20 to 25 m

Sinker
30 to 40 kg

Figure 6: Squid fishing(2) Automatic Squid Fishing Machines
Winding reels (drums) that wind the fishing lines are attached to the automatic
squid fishing machines (Fig. 7). Rotating the winding reel (drum) automaticallyraises or lowers the fishing gear, reeling in squid. An operating panel is attachedto the fishing machines which allows users to adjust the casting speed and depthof the fishing line, as well as the winding speed. In addition, these machines arealso equipped with a squid receptacle (sink), a front roller, and an escapeprevention board (Fig. 8). The fishing gear is attached by winding back the mainline and the fishing line, 20 to 30 squid jigs are attached to the fishing line inintervals of about 1 m, and an anchor is attached at the very bottom (Fig. 9). Squid
that have been reeled in are dropped into the squid receptacle installed on thebottom of the drum. Afterward, they are slid down a chute attached to the side of
the ship which leads to the location where packing is performed.
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Front roller
Front
Drum

Drum

Motor portion,
operating panel

Squid
receptacle

Drum

Side

Figure 8: Automatic squid fishing machinein operation

Figure 7: Automatic squid fishingmachine10

Automatic squid fishing machine
Squid receptacle

Escapeprevention

Front
rollerMain line
200m

board

Chute

Lure
(a few)

Lure

Swivel (also

25 are attached incalledone-meter intervals

yorimodoshi)

Fishing line
7m

(attached between
the fishing lines)

Hook
Fishing line
1m
Figure 9: Example of thestructure of fishing gear

Sinker(3) Fish-Luring Lights
In squid fishing, metal halides are often used as fish-luring lights (Fig. 10). These
are sometimes also used in combination with halogen lights, which have a long
working life.

Figure 10: Metal halide fish-luring lights
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3. Operation Procedures and Content(1) A ship departs from the port carrying boxes and ice. The ship reaches the fishinggrounds by sunset and determines the site for operations by considering suchfactors as the water temperature, wind, current, information from the fish school
detectors, and the positions of other ships.
(2) After arriving at the fishing grounds, the squid fishing machines andreceptacles are prepared, and then the para-anchor is cast, and the ship moves
with the current. In addition, the bow of the ship is turned to face toward thewind using a spanker sail.
(3) Around nightfall, the fish-luring lights are lit. The number of lights is adjusted
based on the fishing conditions. Generally, the largest number of fish-luring
lights are lit in the initial stages of operations. When the fishing depth is deepor operations are carried out before nightfall, the number of lights may be
reduced to guide the squids to a shallower depth.
(4) Based on information from the fish school detectors or sonar devices, the fishinggear is lowered to the depth of the squid, and they are reeled in using theautomatic squid fishing machines. Adjacent automatic squid fishing machines
lower their fishing lines a few seconds apart from each other to avoid tangling.
(5) Squid that have been reeled in detach from the lures and then flow, along withthe seawater, along the chute installed on the side of the ship and are collect in
the center are. These squid are then sorted according to size and packed either
as live or fresh fish (coastal squid fishing vessels) or as frozen fish (deep-sea andshort-sea fishing vessels).
(6) After completing squid fishing, the following operations are conducted: thesinkers are loaded, the receptacles are put away, the spanker sail is stowed, andthe para-anchor is pulled up, in that order.

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(7) Coastal squid fishing vessels return to harbor around sunrise and unload theircatch. When the fishing grounds are distant, fishing vessels may stay offshore
without returning to the harbor in some cases. In this case, one short-sea squid
fishing vessel voyage lasts anywhere from around a few weeks to one month fromdeparture to return to the harbor. During the offshore period, squid fishing
operations are repeatedly carried out.

4. Packing and Unloading
When shipping fresh fish, the caught squid are gathered in one location andpacked. For the boxes, Styrofoam (foam boxes) are typically used.
The quality of the squid is evaluated based on factors such as the body color,
texture, and the transparency of the sashimi (raw meat). If the squid are in directcontact with ice, their body color will turn white. The foamed boxes are first linedwith crushed ice and plastic sheets, then squid about the same size are packed into
the boxes above these layers. This ice-lining method is referred to as shitagoori(bottom-ice). Storing squid using shitagoori preserves the same brown body color
after squid are caught. The number of squid packed per box differs depending on
their sizes, but generally each box is packed with between 5 and 6 kg of squid.
Furthermore, some small ships are equipped with a fish tank for bringing the squidback as live catch.
For deep-sea and short-sea fishing vessels, each voyage lasts a number ofdays, so the caught squid are preserved by freezing. After they are sorted, the squid
are lined up in a case called a pan, and flash-frozen using the ship’s refrigeration
system. Afterward, the clump of frozen squid is removed from the pan and stored
in a freezer on the ship. In addition, freezing is sometimes conducted after carryingout processing known as tsubo-nuki (degutting), which removes the guts andtentacles so that only the body remains.
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Tuna Longline Fishing14

1. Overview
Tuna longlines consist of a main line, a branch lines, floats, and float lines. As
illustrated in Fig. 11, a tuna longline is an item in which one long main line has
many branch lines attached to it that hang down. The branch lines each have afishing hook attached, and each hookFloat

has bait attached. There are also
Float line

floats attached at certain intervals.

Main line

The distance between floats is called
one hachi. The number of branch lines
suspended

in

one

hachi

variesdepending on the swimming depth of

Branchline

the type of fish being targeted.

Figure 11: Outline of tuna longline fishing

Operations are conducted in waters
around the world, including near thecoasts of Japan.

2. Targeted Fish
(1) Types of Tuna・Bluefin tuna: known as kuromaguro, honmaguro, or shibi in Japanese. Youngfish of this species are known as yokowa and meji in Japanese.
・Bigeye tuna: Young fish of this species are also known as daruma in Japanese.
・Yellowfin tuna: Also known as kihada, kiwada, and kiwada maguro in Japanese.
Young fish of this species are also known as kimeji in Japanese.
・Albacore tuna: Also known as binnaga, bincho, tombo, and binnaga maguro inJapanese.

15(2) Marlins
・Striped marlin
・Indo-Pacific blue marlin: also known as kurokajiki, kurokawa, and kurokawa

kajiki in Japanese.
・Black marlin: Also known as shirokajiki, shirokawa, and shirokawa kajiki inJapanese.
・Swordfish: Also known as mekajiki and meka in Japanese.
・Indo-Pacific sailfish: Also known as basho-kajiki and akitaro in Japanese.

3. Main Fish Bycatch
Bonito, Spanish mackerel, mahi, opah, ocean sunfish, and sharks.

4. Bait Used
Types of horse mackerel (such as Japanese horse mackerel, amberstripe scad, and bigeyescad), as well as other seafood such as squid, sardines, and gizzard shad, are used.

5. Structure of Fishing Tools
Float

As shown in Fig. 12, the tuna

Receiving line
Main line

longline is a fishing tool in which a
main line with numerous branch lines
withbarbedhooks

attached

isBranch lines

suspended in the ocean using floats.
Typically, the interval between branch
Figure 12: Structure of fishing equipment

lines is about 50m, resulting in fishing
hooks

with

bait

attached

being

16

interspersed to depths from 100m to 350m, even within a range of one hachi, due
to the main line bending.
(1) Main LineThe main line has a length ranging from about 100 to 120 km. The main line isstored on the ship in a line box or on a
Main line

reel.

Snap

(2) Branch Lines
SwivelBranch lines are the lines attached to

Wire joint leader

a main line with fishing hooks attached

Sinkerto them. They can be attached to the

Fishing base wire
Fishing hookmain line with a snap (Fig. 13).

Figure 13: Structure of branch line

(3) Float
Floats are spherical objects made ofplastic with a diameter of 300 mm. 2 to 3 areconnected to adjust the buoyancy (Fig. 14).
(4) Floating Lines
Floating lines are lines connecting the floats andthe main line. They are generally about 30 m long.

Figure 14: Floats (2) and floating line

The placement depth of the main line is determinedby adjusting the length of the float lines (Fig. 14).
(5) Flag Pole
Flag poles are flags attached to flag buoys. They are attached at the end of themain line when the line casting is complete to serve as a mark for the beginningpoint of line hoisting.

17

(6) Radio Buoys
Radio buoys are buoys that emits radio waves. The
location of these buoys can be confirmed when a shipreceives the radio waves emitted from the buoy (Fig.
15).
(7) Lighted Buoys

Figure 15: Radio buoy

Lighted buoys are lights attached to a float so thatthe location of lines can be confirmed at night when
performing line hoisting (Fig. 16).

6. Fishing Devices(1) Line Casters
Figure 16: Lighted buoys

・Line Shooter
A line shooter is a device that casts a main line thatwas stored in a line box or a reel into the water at a set speed. It is set in the areaof the central stern. A person sits facing the stern, then attaches a snap to the rightside of the line shooter.
・Hooking MasterA hooking master is a device for giving a sound signal for a branch line or a float
to be attached to a main line at a certain interval. A different sound is emitted at
the respective locations for attaching branch lines and floats.
・Bait CasterA bait caster is a machine for casting bait attached to a fishing hook. It runs outof bait less often than throwing by hand and also enables casting to specified
locations.

18Winding roller(2) Line Hoisting Devices

Side roller

Pulling roller
Holding roller

・Line Hauler
A line hauler is a device for hauling a

Main line

main line onto the ship. It is operated
either hydraulically or electrically (Fig. 17).
・Branch Reeler
A branch reeler is a device for winding a

Figure 17: Line hauler

branch line in a coiled shape. A snapping
portion of a branch line disconnected from the mainline is hung between claws in a side roller portion,and the branch line is mechanically wound byrotating the claws (Fig. 18).
Figure 18 Branch Reeler

・Float Winder
A float winder is a device that brings floats onto aship and winds a float line in a coiled shape. The last few meters are pulled up byhand.

7. Main Line Storage Devices(1) Winder
A winder is a device in which a main line having a length of over 100 km is stored
in a line box which is installed near the stern. The line is coiled and dropped evenly
into the box. Also called a line arranger.
(2) Reel
A reel is a device that winds the entirety of a main line on a large reel without
the use of a line box.
19

(3) Mag Reel
A mag reel is a different type of reel. Instead of winding an entire main line on
one large reel, this method uses small, replaceable reels. The main line is divided
into several of these small reels.

8. Line Waiter
A line waiter is a device that stabilizes the behavior of a longline fishing tool thathas been cast and waits for a fish to bite. The waiting time is typically about 4hours. For line returns, it returns to the starting point of casting.

9. Line Hoisting WorkLine hoisting is carried out by all of the crew members. They gather in apredetermined configuration, collect the flag pole in the sea, and commence theline hoisting, beginning work that typically extends for as long as 12 hours. The
work is carried out with periodic rotations between each station.

10. Fish Processing Methods
When fish such as bigeye tuna, bluefin tuna, and yellowfin tuna are caught on alongline, they are quickly processed on the ship. There are four typical processing
methods: rounding, semi-dressing, dressing, and filleting. This section describes
the semi-dressing processing method.

(1) Cut Off the Caudal Fin
Cut off the caudal fin of the fish that has been brought on deck. When cutting off
the caudal fin, the location shown in Fig. 19 is cut. After cutting off the caudal fin,
the fish is killed in a single, quick movement.

20

(2) Killing

Bigeye tuna

Yellowfin tuna

FourthFigure 19: Caudal fin cutting location

Figure 20: Strike

Figure 21: Pierce

Figure 22: Insert

The fish is killed quickly in order to maintain freshness. For small fish, thehead is struck with a mallet or similar implement (Fig. 20). Alternatively, thecrown of the head may be pierced with the pointed end of a metal bar (Fig. 21). For
large fish, cut a hole in the white part of the head as shown and pass a wire along
the spine (Fig. 22).

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(3) Draining Blood
Make a cut in the region of the base of thepectoral fin. Stick a pipe into the operculum, andfeed seawater in (Fig. 23)

Figure 23: Draining blood(4) Removing Gills (Degutting)Insert a knife and split the belly from the anus to the ventral fin. Cut off theanus and the intestines (Fig. 24).
Lift the operculum and cut off the portion connecting the gill cleft to the lower
jaw.
Next, from the gap, insert the knife along the collar, and separate the guts andthe body by cutting. If you hold and pull from the gill cleft, it will be removed alongwith the organs. Lastly, cut the operculum straight off, and cut off the remaining
fins at their bases (Fig. 25).

Figure 24: Cutting the belly open

Figure 25: Removing gills(5) Flash Freezing
After a fish body has been weighed, insert it into the freezing preparation22

chamber to chill. Next, insert each fish into the flash freezing chamber in the orderof processing. Align each fish with gaps in between, making sure the fish do nottouch each other, so that the cold air can circulate sufficiently.
(6) Removal from Freezer (Glazing)
Fish bodies that have been frozen by flash freezing for 12 or more hours aretransferred to a fish hatch. At this time, glazing is conducted in order to prevent
drying or freezer burn as a result of the freezing. The fish are inserted into a metaltank filled with fresh water that has been placed in a freezing chamber, and thefish are dipped inside such that a layer of ice forms over the entire body, including
both the surface and the inside the stomach. For a fish such as a marlin which hasa body bigger than the tank, water is poured over the entire body using a ladle orsimilar tool. After the glazing, each fish is transferred into the fish hatch. Notethat when fish are caught in the waters near Japan, they may also be preservedwith a refrigerating method using materials such as coolant or crushed ice in somecases.

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