Traditional and modern Fishing Crafts: (UNIT IV Fishing Craft and Gear) TYBSc Semester V (Applied component – Marine Sci)

1. Traditional and modern Fishing
Crafts
(UNIT IV Fishing Craft and Gear)
TYBSc Semester V (Applied component –
Marine Sci)
Biren Daftary

2. Overview
• Fishing crafts are essential for catching fish in large
scale in the water bodies.
• A variety of crafts have been designed for this
purpose in India.
• The fishing crafts of India fall under two general
categories in India :
 Non-mechanised boats
 Mechanised boats

3. Non-mechanised Crafts

4. Dugout Canoe
• Used for fishing within small distances from the
shore
• It is a small sized canoe made by scooping logs of
wood in the form of a boat.
• The “Odams”, “Thonies”, “Vanchies” etc. of the
southeast and southwest coasts of India fall
under this category.
• In calm weather, oars may be enough for
propulsion; but if winds and currents prevail, sails
may be used.

5. • For travel in the rougher waters of the ocean,
dugouts can be fitted with outriggers.
• One or two smaller logs are mounted parallel
to the main hull by long poles.
• Outriggers help to balance the boat by
providing support from one side or both the
sides.

6. DUGOUT CANOE

7. OUTRIGGER

8. Plank-built boats
• These are boats made by stitching together
planks of wood.
• There are also an enlarged variety of dugout
canoe made of planks on the side, largely used
in Kerala
• In most of the plank built boats at present, the
carvel type of boat is used.

9. Masula
• Non-rigid boat constructed with planks sewn
together with coir rope, but without any
frames so as to withstand the severe knocking
of the surfs.
• They are made upto 9m in length, although
generally smaller.
• They are of various patterns viz.
Bar boats in Orissa and Padava on the Andhra
Coast

10. A variant with ribs inside has been developed
in the area between Kakinada and
Maslipatnam.

11. Carvel Boats
• Carvel built or carvel planking is a method
of boat building where hull planks are
fastened edge to edge, gaining support from
the frame and forming a smooth surface.

12. Dinghi and Nauka
• These are carvel boats of Orissa and West
Bengal Naukas, which are well designed and
constructed up to a size of 13mx3mx2m are
quite spacious and are used for a variety of
purposes including fishing operations.

13. Tuticorin boats
• These are also called the fishing luggers. They
are carvel boats (11m x 2m x 1m), which are
seaworthy in inshore waters. They are used
more as mother ships and cargo boats than
directly for fishing.

14. FRP Boats
• The term FRP is generally accepted to mean
fibre reinforced plastic.
• It is composed of a series of reinforcements
and liquid chemicals which when brought
together in specific proportions can be formed
into strong, solid but flexible shapes.
• This FRP is then poured into a mould and
when the FRP hardens it is cast out as a solid
and strong hull.

15. • Different type of FRP boats can thus be built
according to suitability by moulding them as
the need be.
• The most common type of the mould used is
called as the female mould which is the mirror
image of a finished hull.
• The mould is made from a plug which is the
exact hand crafted replica of the final hull.

16. • WOODEN PLUG→ FRP MOULD→FRP HULL
• Thus it can be said that the first hull made
from a new mould has been built three times.

18. Advantages & Disadvantages of FRP
Advantages
o Reduction of maintenance
• No leaks. Hulls are one continuous piece of FRP
with no joints or gaps to allow water into the hull.
• No plank shrinkage when laid up. Wooden hulls
suffer from plank shrinkage when brought out of
the water and laid up in the sun. FRP does not
shrink or swell so leakage and re-caulking are
avoided.

19. • Rot proof and resistant to borers. FRP is non-
organic and will not rot. As a plastic it cannot
be eaten by marine borers.
• Corrosion and electrolysis reduced. FRP is
inert. As a plastic it will not corrode.
o Simpler construction. Once a mould is made,
identical copies of a hull can be made many
times over and in a shorter time.
o Reduction of skill levels required once a basic
training is received.

20. Disadvantages
• Total dependance on imported materials and
foreign currency availability.
• Choice of vessel fixed once design is chosen
and moulds made.
• Must retain core group of qualified
technicians.
• Fire and health hazards from chemicals.
• Large start up investment.

21. Motorized Craft
• With the advent of mechanization of the
fishing crafts, small and medium sized boats
are constructed with engines operated by oil
to venture into distant fishing grounds.
• These motorized crafts are: line boats, trap
boats, dol netter, gillnetter and trawlers.

22. Hand line boat
• Operated in both shallow and deeper waters.
• Traditional hand liners use no winch.
• The gear usually consists of a few meters of
monofilament of 0.5-1mm diameter to the
end of which is attached a hood and a sinker,
usually a small stone.
• They are used to catch all kinds of demersal
fish from motorized as well as small
mechanised vessels.

23. Trolling vessel
• They tow lines extending on either side to catch
pelagic species having high individual value and
good quality such as Tuna.
• The lures are attached to outrigger poles through
lines that are towed by a slowly moving vessel.
• The fished hooked after snapping at the lure are
brought on board as the line is hooked in.
• The vessel length vary and have a normal forward
wheelhouse arrangement allowing a clear
working deck.

26. Trawlers
• A fishing trawler is a commercial fishing
vessel designed to operate fishing trawls.
• Trawling is a method of fishing that involves
actively dragging or pulling a trawl through the
water behind one or more trawlers.
• Trawls are fishing nets that are pulled along the
bottom of the sea or in midwater at a specified
depth.
• A trawler may also operate two or more trawl
nets simultaneously (double-rig and multi-rig).

27. • Modern trawlers are usually decked vessels
designed for robustness.
• Their superstructure (wheelhouse and
accommodation) can be forward, midship or aft.
• Motorised winches,electronic
navigation and sonar systems are usually
installed.
• Fishing equipment varies in sophistication
depending on the size of the vessel and the
technology used.

28. Stern Trawler
• On stern trawlers the trawl is set and hauled
over the stern.
• Stern trawlers are designed with or without a
ramp, depending on the size of the vessel.
• Stern trawlers are built for nearly all weather
conditions.
• Trawlers can work as single vessel in bottom
or midwater trawling or as pair trawlers where
two vessels tow one large trawl or a double
trawl.

29. • The most common deck layout of a stern
trawler is such that the wheelhouse is just
forward of the midship with working deck
behind.
• The winch powered by the engine is located
behind the wheel house with the warps
leading to the gantry located at the middle or
sides of the stern.

31. Outboard and inboard engines
• An inboard motor is a marine propulsion
system for boats.
• As opposed to an outboard motor where an
engine is mounted outside the hull of the
craft, an inboard motor is an engine enclosed
within the hull of the boat, usually connected
to a propulsion screw by a driveshaft.

33. • An outboard motor is a propulsion system for boats,
consisting of a self-contained unit that includes
engine, gearbox and propeller or jet drive, designed to
be affixed to the outside of the stern.
• They are the most common motorized method of
propelling small watercraft.
• As well as providing propulsion, outboards provide
steering control, as they are designed to pivot over
their mountings and thus control the direction of
thrust.
• The skeg also acts as a rudder when the engine is not
running. Unlike inboard motors, outboard motors can
be easily removed for storage or repairs.

35. Mechanised craft and their
various operations

36. Gill net
• Gill nets are vertical panels of netting normally set in a
straight line.
• Fish may be caught by gill nets in 3 ways : (1) wedged –
held by the mesh around the body (2) gilled – held by
mesh slipping behind the opercula, or (3) tangled –
held by teeth, spines, maxillaries, or other protrusions
without the body penetrating the mesh.
• Most often fish are gilled.
• Gill nets catch fish that attempt to swim through the
net, which are caught if their head passes through the
mesh but not the rest of the body.

37. • The fish then becomes entangled by the gills
as it attempts to back out of the net.
• The mesh size used depends upon the species
and the size range being targeted.
• Gill nets may be set at or below the surface of
water, on the sea bed or at any depth in
between.

39. Bottom trawls
• A bottom trawl is constructed like a cone-shaped net
that is towed (by one or two boats) on the bottom.
• It consists of a body ending in a cod end, which retains
the catch. Normally the net has two lateral wings
extending forward from the opening.
• The mouth of the trawl is framed by headline and
ground rope. It is designed to catch species living on or
near the bottom.
• Bottom contact with the gear is needed for successful
operations.

40. • Three categories of bottom trawls can be distinguished
based on how their horizontal opening is
maintained: beam trawls, bottom otter trawls,
and bottom pair trawls.
• Beam trawls are commonly designed without wings
• The ground rope equipped with rubber discs, spacers
etc. protect the trawl from damage. On very rough
bottom special rock hopper gears are used.
• Trawl winches installed on deck control the trawling
warps and store them when not in use.

41. • They are towed across the bottom at speeds
ranging from 1 to 7 knots (0.5-3.5 m/s),
frequently between 3 and 5 knots.
• Duration of a tow mainly depends on the
expected density of fish, the shape of the
bottom and the slope in the fishing area, from
a few mins upto 10-12 hours, commonly 3-5
hours.

43. Seine Netting
• It is a bottom fishing method and is of particular
importance in the harvesting of demersal or
ground fish.
• The fish are surrounded by a rope laid out on the
seabed with a trawl shaped net at mid-length.
• As the rope is hauled in, the fish are herded into
the path of the net and caught
• This method of fishing is less fuel-intensive than
trawling and produces a high quality catch.

45. Purse seining
• This is the general name given to the method of
encircling a school of fish with a large wall of net.
• The net is then drawn together underneath the
fish so that they are completely surrounded.
• It is one of the most aggressive methods of
fishing and aims to capture large, dense shoals of
mobile fish such as tuna, mackerel and herring.

47. Long lining
• Long lining is one of the most fuel efficient
catching methods.
• This method is used to capture both demersal
and pelagic fishes including swordfish and tuna.
• It involves setting out a length of line as long as
50-100km long, to which short lengths of line
carrying baited hooks are attached at intervals.
• The lines may be set vertically in the water
column or horizontally along the bottom.

48. • The size of the fish and species caught is
determined by hook size and the type of bait
used.

50. Squid Jigging
• Jigging is widely used to capture squid.
• A jig is a type of grapnel, attached to a line,
which may be manually or mechanically jerked
in the water to trap the fish in its body.
• Jig fishing usually happens at night with the
aid of light attraction
• Squid jigging most often takes place at night
with bright overhead lights to attract the
squid.

51. • Jigs of various types, makes and colour are
attached to the handline at 70 to 90 cm intervals.
Often as many as 8 to 12 jigs are on one line.
• The lines are lowered to 30 to 100 m depth
depending on the strength of the lights used, but
less deep on a small boat with one or two lamps.
• It is important to keep the jig moving constantly
in the water. This is usually done by jerking the
line, quickly pulling in the slack, jerking once
again and so on, until the jig is back to the surface

52. • The line is then thrown out and allowed to
sink to the desired depth, and the same
jerking motion is repeated over again.
• Squids change colour as they move from
shade to light and vice versa and are therfore
difficult to see.
• This explains why they can be difficult to catch
and why jigging is most often the best
method.

54. Bag net
• Bag nets are containers made of nets that are
dragged through the water, collecting the fish
in its path.
• The nets are usually held open by a frame and
the water current.

56. Types of gill nets

57. Purse seines
• It surrounds the fishes in vertical as well as
horizontal position and is used for pelagic fishery.
• The netting walls are long.
• It weighs about 1.25-1.5 tonnes, is 450m long,
40-45m deep.
• One end is joined to the main boat and other end
encircles the area and two ends are brought
together, the fishes are encircled and the net is
pulled up.
• Bout 20-25 people operate it.

59. Cast Net
• Cast nets are popular variety of the small net
operated by a single man.
• It usually has a string.
• The net is cast by the sweep of the arm
• When it spreads the fishes are caught in it.
• The commonly used one is called ‘Ghagria jal’, a
circular or umbrellar net with the chord at the
apex.
• The iron weights are attached on the margin.

60. • When the net is thrown, it spreads, sinks and
the weights make it close.
• It is used for small fishes.

62. Rampani net
• This type of seine net is operated from the beach
or shore and hence the name.
• The net is made up of one hundred to several
hundred rectangular pieces joined together.
• The net is formed of hemp.
• Size of the mesh is smaller at the central portion
than at the side portion.
• Wooden floats are attached to the head rope and
stone sinkers are attached to the foot rope.

63. • The net is operated by 60-80 men.
• In the beginning a scouting boat known as ‘thoni’
is taken into the sea for a survey, and then as the
shoal is sighted, a signal is given to the other
members on the shore.
• Immediately one end of the leading rope is
handed over to the men on the shore and the net
is carried by a larger boat called as ‘Pandi’.
• The net is then laid out in a semicircular fashion
and then pulled by both the groups of men.

65. Tuna Longline
• Longlining is a passive type of fishing technique making use
of lines with baited hooks as fishing gear.
• The longline used for tuna fishing is made up of units each
of which consists of a main horizontal line about 250 to 800
m long with 4 to 15 branch-lines, each with a wire leader
and a hook.
• The depth where the hooks are set in the water column is a
crucial element, this depth in which the longline is settled
can be regulated mainly by modifying the intervals of the
main line between float lines and partially by adjusting the
length of float-line and/or the speed of shooting, to a lesser
extent, by modifying the length of the branch-lines.

67. Dol net
• It is a bag net. Bag nets are conical bag like nets
without wings. The size of the mesh increases
from bag portion to the mouth of the net.
• Dol net is used on the coast of Maharashtra.
• It is a combination of bag net and a fixed trap and
is used for Bombay duck fishery.
• It is a large bag net fixed in the sea by stout
wooden poles or by thick ropes anchored with
heavy stones.
• The net is maintained in a horizontal position
facing the tidal flow.

68. • It is hauled up during the change of tide and the
catch is emptied.
• It is again fixed against the changed direction of
the tide.
• It is operated from 15-20m to greater depths.
• The length of the net is about 56m.
• The width near the mouth of the net is about
30m and the height is about 18m.
• The net gradually tapers towards the other end
i.e. the cod end.

69. • The total length of the wooden pole is about
32m and about 8m remains below the
substratum.
• The mesh size of the net near the mouth is
200m and it gradually reduces to 10mm at the
cod end.

71. Hooks and lines
• Hooks and lines are gear where the fish is
attracted by a natural or artificial bait (lures)
placed on a hook fixed to the end of a line or
snood, on which they get caught.
• Hooks or metallic points (jigs) are also used to
catch fish by ripping them when they pass in
its range of movement.
• Hook and line units may be used singly or in
large numbers.

72. • These gears are hauled by hand in small-scale
fisheries whilst in large-scale fisheries vessels are
usually provided with powered line haulers,
automatic jiggers, line reels, line coilers and
automatic hook handling and baiting systems.
• These gears are suitable for almost any size or
type of vessel that can operate in the area being
worked.
• They can be employed also without boat, directly
from the coastline (jetties, rocks, beaches, etc.).

73. • The fish are attracted by the natural or artificial
bait, hooked, and held by the mouth until they
are brought aboard the operating vessel which
periodically hauls the gear.
• The target species are pelagic, demersal and
benthic.
• Hooks and lines are generally operated in a very
wide range of depths, either in inland and sea
waters. With line fishing it is possible to catch fish
on rough ground, even in their hiding places
between the rocks.

75. Pelagic trawls
• The target is a wide variety of schooling
pelagic species including anchovies, herrings
and mackerels, and fish that gather to spawn
such as sea bass and cod.
• The front net sections are often made of very
large meshes or ropes, which herd the fish
towards the back of the funnel-shaped net.
Pelagic trawls may be towed by one or two
(pair trawl) boats.

76. • Advantages
This method can be highly specific, with little
bycatch of other species, when targeting adult
schools of one species.
• Problems
Pelagic trawls, especially large pair trawls, are
associated with bycatch of cetaceans, turtles, and
other marine mammals in some areas, such as
common dolphins in the sea bass pair trawl fishery
in the English Channel. Bycatch of juvenile fish of
the target species may also be high in some
fisheries.

78. END OF UNIT IV