Fisheries Technologies for Developing Countries (1988) / Chapter Skim
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2. Fishing Methods and Gear
2. Fishing Methods and Gear
Pages 49-84
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From page 49... ...
Each method shows a continuum of development with evolution resulting from modernizing factors. Traditional fishing arts in various stages of modernization could be transferred and applied in new regions with the technical level appropriate for the local conditions.
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From page 50... ...
Fishing rods can be set untended in shallow waters or on the beach. ~ the ocean, set lines may be suspended from the surface.
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- ~~ . ~ FIGURE 2.1 Multiple-baited hooks on a line can increase the catch.
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It has rigid branches to allow multiple hooks without snagging. Fishermen can use local materials to fabricate this gear.
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(Atlantic and Gulf Fishing Supply Corp.)
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From page 54... ...
Simple mechanical hauling techniques can increase the range and depth of hand-line fishing. Manually operated reels can be constructed of local materials and used to reduce the effort needed to handle gear.
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, depleting marine resources. Traps increasingly tend to be constructed of more durable materials, such as wire mesh and vinyI-ciad wire netting, instead of traditional woods and fibers.
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These traps are set in long rows, about 40 m apart. The use of mangrove boughs to cover trap roofs provides attractive shade and shelter for some species.
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From page 57... ...
It is usually pulled and cleared every third day. Variations of Caribbean Island fish traps incorporate exterior funnels leading into a cone-shaped interior funnel that is often turned down to prevent escape.
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Corrosion is always a serious problem with metal traps. One solution is to use marine mesh, which combines the strength of
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From page 59... ...
This design creates four chambers, each about 15 x 35 cm, by dividing two pipes in half with a concrete plug. / 1 ~ ~ 1 ~ car tire ~ cut in thirds I \ lac ing nail / - ' wood disk ~ Gang ion J FIGURE 2.8 For use as octopus pots, discarded tires can be cut in thirds, laced into cylinders, and closed at one end with a wooden disc.
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From page 60... ...
Some collapsible traps made of wire mesh and plastic are commercially available, but there is a need for local research in this area. Weirs and Trap Nets Large traps can be built in shallow coastal waters to capture sizable schools of fish such as salmon, bonito, tuna, herring, sardines, and cod.
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From page 61... ...
Weirs and trap nets have a number of advantages that favor their use in developing countries. They may be constructed of local materials and use little or no energy.
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From page 62... ...
From the corral, a narrow opening leads into a smaller holding pool or crib with a net floor to make fish recovery easier. A similar Caribbean trap net is used to capture crabs.
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From page 63... ...
~ _... =_ .~ _ —_ ~ 'he ~ Shore it, 63 we_ Corral {.~' /' __ ,, ~ ~ · 1~ FIGURE 2.11 This Caribbean trap net is ret to capture fish swimming parallel to the shore.
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From page 64... ...
In intertidal areas, the nets may be driven into the bottom and the fish collected at low tide. Taiwanese fishermen tie scare ropes around their bodies and swim as a group toward a fixed net.
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From page 65... ...
T ~ 3 (XXA/Y X AAA~AAA~Y~ Y A The mesh size of a gill net determines the size of the fish FIGURE 2.14 Trammel nets capture fish in a pocket of netting.
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From page 66... ...
. ,,, :,:, _ _ ~ 4 ~ _ FIGURE 2.15 Entangling nets can be used at the surface, midwater, or on the bottom, either anchored or free-floating, depending on the target fish.
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From page 67... ...
Operated from the ship's side, it can almost be as wide as the vessel's length (figure 2.17~. Four-boat liftnets are common in Scandinavian and Southeast Asian fisheries.
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ACTIVE GEAR Active gear has to be moved, dragged, or towed in order to capture fish. This usually requires engine-propelled boats and usually involves additional investment over passive or stationary gear.
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Changing sinker weights allows fishing at graduated depths. I,ures can be made of local materials and easily changed for the target species.
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In some cases, regular baited hooks are jigged manually or mechanically to attract attention to the bait. Special reels can be used to impart a jigging action to the line (figure 2.20~.
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At the same time, it is labor intensive and time consuming, unless relatively expensive jigging machines are employed. Jigging requires knowledge of the local area to determine where and when it can be used.
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From page 72... ...
Small two-man beach seines are often used for catching live bait or small fish (figure 2.22~. These tend to have a uniform small mesh.
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From page 73... ...
FISHING METHODS AND GEAR 73 FIGURE 2.21 Using large beach seines is a group effort. One end is held on the beach while the other is rowed in a curve back to the beach and hauled in.
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From page 74... ...
_ - ~ ~r~ FIGURE 2.23 Large boat seines are used by anchoring one end of the seine, sailing in a circle back to the anchor point, and hauling the net. The purse seine can be set with one or two boats and must be fished quickly.
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From page 75... ...
Bottom Bawling Trawls may be towed behind one or two boats or, in shallow waters, even dragged by a fisherman (figure 2.27~. Trawl nets generally have a cone-shaped body with a wide opening between two wings.
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From page 76... ...
With the same total horsepower, more fish can be caught with pair trawling than if a single boat tows the net. Whereas the noise from a single engine directly in front of the trawl net can frighten fish from the path of the net, the noise from two engines on either side of the opening will scare some fish towards the center, directly into the net.
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From page 77... ...
Single Boat Trawling A single vessel with an adequate power source may also tow a trawl, but otter boards or a beam are required to open the net horizontally. Beam trawls are the simplest trawls and are used primarily to capture Catfish and shrimp (figure 2.29~.
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From page 78... ...
action of the heavy otter boards (figure 2.30~. Demersal or pelagic species can be captured by this fishing method in shallow waters.
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From page 79... ...
FISHING METHODS AND GEAR 79 ...,.—-j ~ { -- air Al Q~ l /~-QQ `~- Q ~ ~ ~ _ my ..k . ~ g FIGURE 2.28 Boats without enough power to trawl singly can often trawl in padre.
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From page 80... ...
Seawater temperature can markedly affect fish-feeding habits, and in thermally stratified water, species may concentrate
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From page 81... ...
Simple digital readout electronic thermometers can display instantaneous temperature changes of tenths of a degree. These are available for less than $100.
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In situations where specific gear is potentially valuable but too costly for a fishing community, adaptive research on local manufacture using local materials could be an alternative.
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From page 83... ...
Israel Program for Scientific Translations, Jerusalem, Israel. Atlantic and Gulf Fishing Supply Corporation.
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From page 84... ...
1985. Octopus fishery information leaflet, Gulf and South Atlantic Fisheries Development Foundation, Miami, Florida, USA.
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