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Page 1: Fishing Gear Assignment

Marine Fishing Gear & Fishing Method

(GS/M.Sc./FOOD/3608/08)

B.K.K.K. Jinadasa

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A fishing gear is the tool with which aquatic resources are captured, whereas the fishing method is how

the gear is used. Gear also includes harvesting organisms when no particular gear (tool) is involved.

Furthermore, the same fishing gear can be used in different ways. Fish capture technology encompasses

the process of catching any aquatic animal, using any kind of fishing methods, often operated from a

vessel. Use of fishing methods varies, depending on the types of fisheries. The large diversity of target

species in capture fisheries and their wide distribution requires a variety of fishing gear and methods for

efficient harvest. These technologies have developed around the world according to local traditions and,

not least, technological advances in various disciplines. In recent decades major improvements in fiber

technology, along with the introduction of other modern materials, have made possible, for example,

changes in the design and size of fishing nets. The mechanization of gear handling has vastly expanded

the scale on which fishing operations can take place. Improved vessel and gear designs, using computer-

aided design methods, have increased the general economics of fishing operations. The development of

electronic instruments and fish detection equipment has led to the more rapid location of fish and the

lowering of the unit costs of harvesting, particularly as this equipment becomes more widespread.

Developments in refrigeration, ice-making and fish processing equipment have contributed to the design

of vessels capable of remaining at sea for extended periods.

A common way to classify fishing gears and methods is based on the principles of how the fish or other

preys are captured and, to a lesser extent, on the gear construction. We can classify the main categories

of fishing gear as follows:

Towed or Dragged gear

i. Trawling

ii. Dredging

1. Encircling gear

i. Purse seine

ii. Beach seine

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2. Statics gear

i. Gill nets

ii. Trap nets

iii. Long line

iv. Pots and traps

3. Other mobile gear

i. Line fishing

ii. Net fishing

iii. Harpooning

iv. Collecting

v. Trolling

vi. Lift net

Fishing gears can be classified other ways also, which is;

1. Active fishing gear

Fishing gears are move here,

i. Herding fish in to fish – trawl net, seine net

ii. Encircling net

iii. Catching by aggregation (FAD)

Using repellents - sound, color, visible objective

Using attractants – Baiting (live or artificial), lightening

2. Passive fishing gear

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Fishing gear is not move here.

i. Passively laid net

ii. Fixed traps

Fishing gear can be classified according to the fishing methods for commercially important species

1. Demersal Species (Whitefish such as Cod, Haddock, Whiting, Flatfish, etc.)

Bottom Trawling (Single-boat)

Bottom Trawling (Pair)

Seine Netting

Pair Seining

Beam Trawling

Long lining

Set-nets

2. Pelagic Species , Mackerel, Sprat)

Purse Seining

Mid-water Trawling (Pair)

Mid-water Trawling (Single-boat)

3. Shellfish (Nephrops, Shrimps, Scallops, Queens, Lobsters, Crabs, etc.)

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Bottom Trawling (Single-boat)

Scallop Dredging

Potting and Creeling

4. Migrating Game Fish (Salmon, Sea trout)

Bag-Nets, Stake-Nets

Beach-Seining

Haaf-Nets

Trawling:

Trawling is the operation of towing a net to catch fish, and the basic requirements for operating the

trawl-net are sufficient power to tow the net, a means of holding the mouth of the net open while

towing, a system of wires to connect the net and gear to the source of towing power and the ability to

cast and haul the net. Vessels provide the necessary towing power, from small inshore boats up to large

deep-sea trawlers, with the size of gear scaled to match available horsepower. They may be designed to

tow the fishing gear either from the side or from the stern and also provide accommodation for the

crew, transportation to and from the fishing grounds and a working platform for fishing operations.

Winches installed on deck move and store the trawling wires or warps. Auxiliary winches, power blocks

and net drums or used to handle the gear while hauling and shooting. A fishing trawler is a commercial

fishing vessel designed to operate fishing trawls. Trawling is a method of fishing that involves actively

pulling a trawl through the water behind one or more trawlers. Trawls are fishing nets that are dragged

along the bottom of the sea or in mid water at a specified depth. A trawler may also operate two or

more trawl nets simultaneously. There are many variants of trawling gear. They vary according to local

traditions, bottom conditions, and how large and powerful the trawling boats are.

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Main trawling types are:

1. Bottom trawling

2. Mid water trawling (pelagic trawling)

3. Dredging

But there are so many types of trawling, Demersal Otter Trawling, Shooting and Hauling Otter Trawl

Gear, Twin Rig Trawling, Demersal Pair Trawling, Beam Trawling, Shellfish Trawling, Pelagic Pair Trawling

(Mid-water Trawling), Pelagic Single Boat Trawling etc.

Bottom trawling

Bottom trawling is trawling (towing a trawl, which is a

fishing net) along the sea floor. Bottom trawling

targets both bottom living fish (ground fish) and semi-

pelagic species such as cod, squid, shrimp, and rockfish.

Bottom trawling can be carried out by one trawler or by two

trawlers fishing cooperatively (pair trawling). Bottom trawling has been widely implicated in the

opulation collapse of a variety of fish species, locally and worldwide, including orange roughy, barndoor

skate, shark, and many others. Today, some countries regulate bottom trawling within their

jurisdictions.

Mid water (Pelagic) trawling

Mid water trawling is trawling, or net fishing, at a depth that is higher in the water column than the

bottom of the ocean. It is contrasted with bottom trawling. Mid water trawling is also known as pelagic

trawling and bottom trawling as benthic trawling. In mid water trawling, a cone-shaped net can be

towed behind a single boat and spread by trawl doors, or it can be towed behind two boats (pair

trawling) which act as the spreading device. Mid water trawling catches pelagic fish such as anchovies,

shrimp, tuna and mackerel, whereas bottom trawling targets both bottom living fish (ground fish) and

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semi-pelagic fish such as: cod, squid, halibut and rockfish. Whereas bottom trawling can leave serious

incidental damage to the sea bottom in its trail, mid water trawling by contrast is relatively benign.

Dredging

Dredge consists of a ruggedly constructed triangular steel frame and

tooth be bearing bar or sword, behind which a mat of linked steel rings is

secured. A heavy netting cover or back is laced to frame, sides and after end of this

mat to form a bag in which the catch is retained. Scallops, which

usually lie recessed in sand and fine gravel, are raked out by the teeth

and swept into the bag. Several dredges are shackled to a hollow

steel tow bar fitted with chain bridles, one for each dredge. The

entire assembly is towed on a single wire warp and larger vessels generally tow two bars, one on each

quarter. Ships rigged for beam trawling deploy dredge arrays from outrigger booms in the manner of

beam trawls. The number of dredges used varies with towing power, handling capabilities and area, with

fourteen (i.e. seven on each side) a fairly typical number, although the largest vessels may deploy more.

The target group is mollusks, scallops etc.

Impacts Environmental see the environmental impact caused by Bottom trawls; Beam trawls; trawls.

The major potential detrimental impact of trawling on species can be the capture and removal from the

ecosystem of small sized organisms and non-target species, which frequently are discarded at sea. Such

impact can be mitigated by using larger meshes in the cod ends and/or devices in the trawl that reduce

capture of small and unwanted organisms.

Purse-Seining

The seine netting method developed in Denmark. Scottish

seining ("fly dragging") was a later modification. The original procedure

is much the same as fly dragging except for the use of an

anchored marker buoy when hauling, and closing the

net and warps and net by winch. A common type of

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seine is a purse seine, n because along the bottom are a number of

rings. A rope passes through all the rings, and when pulled, draws the rings close to one another,

preventing the fish from "sounding", or swimming down to escape the net. This operation is similar to a

traditional style purse, which has a drawstring. The purse seine is a preferred technique for capturing

fish species which school, or aggregate, close to the surface: such as sardines, mackerel, anchovies,

herring, certain species of tuna (schooling); and salmon soon before they swim up rivers and streams to

spawn (aggregation). Boats equipped with purse seines are called purse seiners. Impacts Species;

incidental capture of dolphins by tuna purse seiners is regarded as an irresponsible fishing practice.

Special techniques have been developed to reduce by catch of dolphins; the Medina panel and "back

down" operation, which ensure that encircled dolphins are released alive. The increasingly used practice

of encircling floating objects, including man-made FADs increases the capture of small sized and

immature aggregating around such devices.

Beach seine

A seine net is a very long net, with or without a bag in the centre,

which set either from the shore or from a boat for surrounding a

certain area and is operated with two (long) ropes fixed

to its ends (for hauling and herding the fish). Two types of

gear can be distinguished in this category: beach seines and boat

seines. no specific gear handling equipment is required for

beach seine operations, the problem for maneuvering seine

nets in general consists, first, in hauling the long ropes attached to the ends of the net: this is done

either by hand (Beach seines) or with a winch (Boat seines). When seine nets are used from boats, rope

drums can be used for storing the long ropes, a power block can also help for bringing the net on board.

For the operation of a beach seine, only rather small undecked vessels may be necessary for setting the

net. The boat seines are operated from a wide range of rather small and simple boats and by modern

specialized medium size units with specific deck equipment. According to the fishing technique used,

seine nets can be operated by medium and large decked vessels. Fish operation of Seines are usually

set from a boat to surround a certain area and are hauled either from the shore (beach seines) or from the

boat itself (boat seines). Target Species are mainly demersal species, less frequently for pelagic species.

Seine nets are operated both in inland and in marine waters. The surrounded and catching area depends

on the length of the seine and of the hauling lines. The seine nets are used, in marine waters, on the

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continental shelf, from the coast to down to 500 m and are very common everywhere, lakes, large rivers,

etc. The potential negative impact may consist in the by catch/discards (undersize specimens, no

marketable specimens, non target species, etc.) and results from the use of a large net, with, frequently,

too small meshes, in coastal waters.

Gill nets (Set nets)

Set-nets are long walls of netting which trap fish either

by gilling or entanglement, depending on the

size of mesh and the tightness of the netting. The

netting is hung on ropes and the hanging ratio can

range from a loose 0.3 for tangling fish to a tight 0.6

for gilling. Nets for demersal fish are 1.5 m - 6 m deep

and between 50 and 200 m long. The netting is

mostly woven from fine nylon twine, which is practically

invisible underwater under most conditions. Twine thickness ranges from 0.2 to 0.9 mm. Several

types of twine are available and the choice is a compromise between stiffness for ease of handling and

softness for catching efficiency. Multi-monofilament twine is commonly used and this consists of 8 to 12

strands of thin monofilament, about 0.15 mm thick, lightly twisted together. Plastic floats, either ring,

cylindrical or egg-shaped, are attached to the headline to keep the netting upright. Floats need to be

slightly larger than the mesh opening to prevent them from tangling the netting. Ring floats are convenient

as the nets can then be mounted on a solid rod for shooting without snagging. A lead-cored line is

attached to the footrope to ensure bottom contact. On large mesh nets for ground fish such as angler

(monkfish) and skate that are found tight on the bottom, a polypropylene headline rope without floats

provides sufficient uplift. In areas where currents are strong, additional weighting may be added to the

solerope. The nets may be used singly or a number joined in fleets with suitable moorings to hold them in

place. Mammals in larger mesh nets in shallow water, In tightly hung gill nets the mesh size is chosen to

allow only the head and gill covers of the targeted size of fish to pass through and be trapped. Mesh sizes

range from 60 mm for bait nets to over 200 mm for large bodied cod and saithe. Mesh size is less

important in loosely hung tangle nets. Most fish twist and turn when trying to escape and become much

entangled, but a sizable proportion is still caught by gilling. Much larger mesh sizes over 250 mm are

used in tangle nets for skate, crayfish and occasionally lobster. A more complex type of set-net is the

trammel-net, with three panels of netting hung together. The inner panel of small mesh netting is very

loosely hung between two outer panels of large mesh netting. When a fish strikes the net it pushes the

small-meshed netting forward through the large mesh, forming a pocket in which it is trapped. In inshore

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waters set-nets are mainly fished seasonally by small boats for a variety of demersal species. Wrecks and

other areas where fish concentrate are fished, and the nets are usually left in the water overnight. If they

are left much longer the catch attracts crabs which quickly destroy the trapped fish. Removing crabs from

the netting is a tedious and time consuming business. Most small vessels now have powered haulers to

recover their nets. Larger vessels which fish offshore may have more elaborate machinery for hauling,

clearing and stacking the nets and can work over 20 km of nets. The main advantage of set nets over

towed nets for demersal species is that when tightly hung they are very size selective and retain few

juveniles. If shot and hauled quickly the fish quality can be good. They can be used on very rough

grounds inaccessible to towed gears. By-catches of crabs are a problem in some fisheries and there is

also a risk of catching sea birds and large mammals in larger mesh nets in shallow water.

Long line:

Longline fishing is a commercial fishing technique. It uses a long line, called the main

line, with baited hooks attached at intervals by means of branch lines called

"snoods". A snood is a short length of line, attached to the main line using a clip or

swivel, with the hook at the other end. Loglines are classified mainly by where they are

placed in the water column. This can be at the surface or at the bottom. Lines can also

be set by means of an anchor, or left to drift. Hundreds or even thousands of

baited hooks can hang from a single line. Long liners commonly target swordfish,

tuna, halibut, sablefish and many other species. In some unstable fisheries, such as the

Patagonian tooth fish, fishermen may be limited to as few as 25 hooks per line. In

contrast, commercial long liners in certain robust fisheries of the Bering Sea

and North Pacific generally run over 2,500 hand-baited hooks on a single series of

connected lines many miles in Longlines can be set to hang near the surface (pelagic

longline) to catch fish such as tuna and swordfish or along the sea floor (demersal

longline) for groundfish such as halibut or cod. Long liners fishing for sablefish, also

referred to as black cod, occasionally

set gear on the sea floor at depths exceeding 1,100 metres (3,600 ft) using relatively

simple equipment. Longlines with traps attached rather than hooks can be used

for crab fishing in deep waters. Longline fishing is prone to the incidental catching and killing of seabirds

and sea turtles. Otherwise, compared to other fishing techniques such as bottom trawling, longline fishing

is less destructive to bottom habitats. It generally has good species selectivity and low fuel consumption.

Great Lines

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A great line, as the name suggests, employs heavier main lines and is used in deep water for catching

halibut, cod, ling, tusk and skate. A traditional great line may consist of up to 30 long lines. Each line is

typically made up of six strings of 16 hooks fastened together end to end. One vessel may use three or

four great lines, with a total length of up to 20 Km, bearing up to 12,000 hooks. For many years pre-baited

strings were shot from wooden tubs placed in sequence at the shooting station situated at the vessel’s

side or stern. As one string was shot the next was moved up and its leading edge joined to the tail end of

the preceding string. On modern long liners, however, shooting and hauling procedures have become

fully mechanized. Lines are shot directly over the stern through a small hatch in the deck shelter.

Automatic baiting machines ensure that each hook carries fresh bait every haul and the line magazines

which store line and hooks in sequence greatly reduce the possibilities of foul gear. With mechanized

systems up to 48,000 hooks may be worked per day. Lines are hauled using a constant tension

combination hauler which untwists and racks the line after smaller fish are removed by the hook cleaner.

Larger fish may have to be gaffed aboard. As hauling proceeds the line magazines are automatically filled

in sequence ready for shooting. Long liners may spend many days, even weeks, at sea on fishing banks

many hundreds of miles offshore with the catch preserved on ice or frozen. Enclosed deck shelters as

well as the machinery described above have considerably improved working conditions for crews in what

has always been an arduous and sometimes perilous fishery.

Small Lines

Small lines are much lighter than great lines and are fished from small boats operating on grounds near

their home port. The hooks are usually baited ashore and the strings laid in special wooden trays, open at

one end and deeper at the other. Each string is coiled into the deep end, and as the hooks come to hand

they are baited with mussel, lugworm or pieces of fish, and then carefully laid side by side and row upon

row in the shallow part of the tray, starting at the back and working towards the open end. Each row is

separated by material such as newspaper to minimize hooks fouling when shooting.

On board the vessel the trays are placed in series near and leading to a metal chute over the stern. After

the anchor and first dan are lowered on the fishing grounds the vessel steams slowly along with the

strings running out over the metal chute. Each line can bear up to 1,200 hooks and three or four lines may

be fished per day. When the lines are shot and the end anchor and dan set they are left for several hours,

during which time the crew may fish with hand lines before starting to haul. This may be done by hand but

a small mechanical line hauler can be used if engine power is available. After recovering all the gear the

vessel immediately returns to port to land the catch in prime condition.

Pots and Traps:

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Traps, large stationary nets or barrages or pots, are gears in which the fish are retained or enter

voluntarily and will be hampered from escaping. They are designed in such manner that the entrance

itself became a non-return device, allowing the fish to enter the trap but making it impossible to leave the

catching chamber. Traps are baited or not. Pieces of fish are often used as bait. Artificial baits are also in

use. Other types of traps are provided with large guiding panels made from netting to lead the fish into the

catching chamber. Different materials are used for building a trap; wood, split bamboo, netting wire are

some examples. Handling equipment of traps, large stationary nets type, is usually hauled by hand but for

pot haulers are increasingly used, especially for hauling pots from deep waters. Larger traps like pound

nets are increasingly handled with hydraulic hauling devices, like "ball-rollers". Fish Operation; these are

a group of gear in which the fish enters voluntarily, but is hampered from coming out. Fishermen visit

traps regularly for collecting the catch and replacing bait, if any, leaving the gears set in the same place

for several days. Traps like Pots can more easily be moved from one fishing location to another. Target

Species; large stationary nets or barrages are used to catch migrating fish (pelagic and demersal). Pots

are used for catching lobster, crabs, shrimps, octopus, eels, and all kinds of reef fish and euryhaline

species. Traps are operated in a very wide range of depths, either in inland, in estuarine and sea waters.

Large traps (stationary nets or barrages) are set in coastal waters; pots can be anywhere up to several

hundred meters depth. Impacts Species are low negative environmental impact, caught juveniles or

undersized species

can be released alive.

Mesh size in the trap can

also be used to release

small sized

individuals. Lost pot will

continue to fish and thus

"ghost fish" but, in more

and more fisheries,

a regulation requires

that a pot includes some escapement window/panel.

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Pots are constructed either of wooden slats or, more commonly, coated wire mesh. They are set on the

bottom individually or in strings and harvest various species of shellfish and finfish. In New Jersey's

waters they are used to trap lobster, blue crabs, whelks (often called conch) and sea bass. Pot fishing can

be done in shallow estuaries, in inshore ocean waters and in deeper water offshore. The traps range in

size from the two or three foot long crab pots to the very large, deep water traps used in the Bering Sea

tanner and king crab fisheries. These can be ten feet square. The smaller pots are hauled from the

bottom by hand while the larger traps require hydraulic haulers. The pots are usually baited but often,

particularly on flat, sandy bottoms, it is thought that the quarry enters traps as much for the shelter they

offer as for food.

Aerial traps

Jumping fish and gliding fish can be caught on the surface in boxes, rafts, boats and nets ("verandah

nets"). Sometimes the fish are frightened to get them to jump out of the water. Handling of the equipment

is setting and use of such gears is done by hand and do not require specific equipment. Usually used

from small size open boats. Fish Operation; fishermen have learned to use the jumping habit of fish to

catch them setting boxes, rafts, nets on the water surface or using boats. Sometimes the fish are

frightened to get them to jump out of the water. Target species are jumping fish (e.g., mullets) and gliding

fish (flying fish). Gear Environment of aerial traps is generally operated in coastal zones either in inland, in

estuarine and sea waters. They are usually set on the surface.

Lift net

Lift nets are horizontal netting panels or bag shaped like a

parallelepiped, pyramid or cone with the opening facing upwards

which are submerged at a certain depth, left for a while, the time

necessary for light or bait to attract fish over the opening, then lifted out

of the water. Three main types of lift nets can be distinguished:

portable hand lift nets (used, in general, with light attraction), shore

operated stationary lift nets.

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Handling Equipment; lift nets are hauled out by hand or mechanically through bomm(s) and blocks. The

handling (setting and hauling) of large lift nets, normally requires, in addition, one or several winches.

Vessel Overview; boat-operated lift nets are often used, in small-scale fisheries, from small catamans

(e.g. in inland fisheries, in Africa) or two canoes operating together; other models of lift nets, larger (i.e.

bag nets, "basnig", in Asia) are handled, from large vessels, known as Lift netters. In some other cases

no boats are required (for shore stationary installations).

The operations, from the shore, from a canoe or a bigger boat, include - the setting of the net at a certain

depth, opening facing upwards; - the attraction of the fish over the above mentioned opening, by light or

bait; then, - the lifting/hauling of the net out of the water, by hand or mechanically. Target Species are

small pelagic species, fish and squid.

Gear Environment of lift nets are, in general, active a few meters below the surface; when light attraction

is used, the active depth depends on the attraction power of the light; this differs much if lamps (one or

several) are above the surface or if under-water lamps are used; with the former, the power of the lamp

and the number of these is the criteria; with the later, things depend on the length of the under-water

power cable to the lamps); either in sea and inland waters.

Impacts Species of the lift net impact of the use of lift nets depends on how selective is the attraction

above the lift net opening, mainly attraction to the light. Certain species or smaller sizes of fish can be

attracted, at the same time, in addition to target species (a by catch which is some time discarded). Socio-

economic It is also worth mentioning in respect to the use of light attraction with lift nets for squid fishing,

that, in far east Asia, with the steep increasing of the power of lights, a decrease of the effectiveness of

each individual lift netter fishing in fleets, not so far one to each other, has been observed.

Trolling

Trolling is a method of fishing where one or more fishing lines, baited

with lures or bait fish, are drawn through the water. This may be

behind a moving boat, or by slowly winding the line in when fishing from a

static position, or even sweeping the line from side-to-side, e.g. when

fishing from a jetty. Trolling is used to catch pelagic fish such as salmon,

mackerel and kingfish.

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Trolling can be phonetically confused with trawling, a completely different method of fishing, where a net

(trawl) is drawn through the water instead of lines. Trolling is used both for recreational and commercial

fishing whereas trawling is used mainly for commercial fishing. Trolling from a moving boat is a technique

of big-game fishing and is used when fishing from boats to catch large open-water species such as tuna

and marlin. Trolling is also a freshwater angling technique.

Trolling from a moving boat involves moving quite slowly through the water; this may be accomplished by

use of a special trolling motor. Many anglers troll for some or most of their fish. In saltwater, trolling is a

critical method for catching many pelagic species, especially billfish, and important for pursuing many

inshore species, including kingfish, bluefish, and various jacks. There is plenty of science and drama

involved, whether the quarry is blue marlin, chinook salmon, walleye, or dolphin

Harpoon

A harpoon is a long spear-like instrument used in fishing to catch fish or

large marine mammals such as whales. It accomplishes this task

by impaling the target animal, allowing the fishermen to use a rope

or chain attached to the butt of the projectile to catch the animal.

A harpoon can also be used as a weapon. The modern whaling harpoon

consists of a deck-mounted launcher (mostly a cannon) and a

projectile which is a large harpoon connected to a thick rope. The

spearhead is shaped in a manner which allows it to penetrate the thick layers of whale blubber and stick

in the flesh. It has sharp spikes to prevent the harpoon from sliding out. Thus, by pulling the rope with a

motor, the whalers can drag the whale back to their ship. A recent development in harpoon technology is

the hand-held speargun. Divers use the speargun for defense against dangerous marine animals. They

are also used for spearing fish. Spearguns may be powered by pressurized gas or with mechanical

means like springs or elastic bands

Dive-caught

Free diving (using mask and snorkel) or scuba diving is a traditional method of collecting lobster, abalone,

seaweed, sponges and reef dwelling fish (groupers and snappers) for example. In deeper waters helmet

diving systems using air pumped from the surface are used. Species, including high value species such

as geoduck (giant clam), urchins, sea cucumber, lobster and scallops are now widely harvested by divers.

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Hand-collection by divers is potentially one of the most species selective and least damaging fishing

methods, provided harvesting is carried out responsibly.

Drift net

Drift nets are not set or fixed in any way, are in fact ‘mobile’, and they are allowed to drift with the

prevailing currents. Drift nets are used on the high seas for the capture of a wide range of fish including

tuna, squid and shark, and off north-east England for salmon. Despite a global moratorium on large-scale

drift nets (nets exceeding 2.5 Km in length), introduced in 1992, problems still exist. For example, drift net

fisheries in the Mediterranean for swordfish and albacore tuna pose a particular threat to striped dolphins.

Pole and line

Pole and line fishing (also known as bait boat fishing) is used to catch naturally schooling fish which can

be attracted to the surface. It is particularly effective for tunas (skipjack and albacore). The method almost

always involves the use of live bait (anchovies, sardines etc.) which is thrown overboard to attract the

target species near the boat (chumming). Poles and lines with barbless hooks are then used to hook the

fish and bring them on board. Hydraulically operated rods or automatic angling machines may be used on

larger pole and line vessels.

Use of explosives (dynamite) or poisons (sodium cyanide, bleach)

Dynamite fishing; In some countries such as the Philippines, explosives (dynamite or blast fishing) are

used on coral reefs to capture fish. Blast fishing is a particularly destructive method of fishing and is

prohibited in many regions. A single explosion can destroy square meters of coral in the immediate area,

whilst shock waves can kill fish in a radius of 50m or more from the blast. Reefs in some parts of South

East Asia have been reduced to rubble in this way.

Cyanide poisoning; Cyanide is used by fishermen in many areas of South East Asia, the Pacific and the

Indian Ocean, to stun reef fish such as grouper and Napoleon wrasse which are then exported for the live

reef fish food market or aquarium trade. Although its use is prohibited the practice continues because of

the demand for certain species (e.g. Napoleon wrasse) as gourmet delicacies.

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[Marine Fishing Gears & Fishing Methods] 17

References:

Commercial fishing methods: an introduction to vessels and gears. Sainsbury JC (1996). Third Edition.

Fishing News Books, Oxford.

Commercial fishing: the wider ecological impacts. Edited by G Moore & S Jennings (2000). Blackwell

Science Ltd.

Definition and classification of fishing gear categories. FAO fisheries technical paper 222 (1999)