Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01K—ANIMAL HUSBANDRY; AVICULTURE; APICULTURE; PISCICULTURE; FISHING; REARING OR BREEDING ANIMALS, NOT OTHERWISE PROVIDED FOR; NEW BREEDS OF ANIMALS
  • A01K73/00—Drawn nets
  • A01K73/12—Nets held vertically in the water, e.g. seines

Definitions

• the present invention relates to a method for fishing for tuna and similar fish.
• the invention also relates to a device for implementing this method, and an assembly of such devices.
• similar fish is meant here fish presenting mores analogous to those of tuna, more precisely fish tending to gather under floating bodies such as pontoons or floating wrecks.
• a known method of tuna fishing consists in catching the fish by means of a net deployed vertically in an approximately cylindrical arrangement. The net is then tightened and the fish is recovered there by means of landing nets.
• the difficulty in this type of fishing consists in locating a particularly fishy area where to cast the net. This detection is carried out either by aiming from aircraft, or by measuring the water temperature, to locate areas where, due to its manners, fish are more likely to be located.
• the present invention aims to carry out a method which gives increased efficiency in catching by net by making it possible to operate on areas with a high concentration of fish.
• the invention also relates to a device for applying this method.
• the method for fishing for tuna and similar fish consists in surrounding a certain area of the sea by means of a net which is then closed. It is characterized in that, before placing the net, a raft having a certain opacity is placed in said zone, and in that the net is placed after having observed a sufficient gathering of fish under the raft. No search for a fishing area is then necessary since the concentration of the fish is operated artificially by the presence of the raft in the chosen area.
• the device for fishing for tuna and similar fish is characterized in that it comprises a flexible floating ring whose interior is occupied by a relatively opaque surface.
• the raft can be easily folded up and stored on board between the actual fishing operations.
• the device comprises a peripheral net fixed on the periphery of the raft, and attachment means for keeping the net folded at the level of the raft, these attachment means being unlocked to allow the net to deploy and extend under the raft. Thanks to this arrangement, the use of an auxiliary vessel to deploy the net around the raft is avoided.
• the device comprises a number of guide hoops fixed under the raft to guide the net in its movement, to form a bell under the raft.
• a drawstring is threaded along the lower edge of the net.
• - Figure 1 is a plan view of a device according to the invention, with indication of the maneuvers corresponding to a certain mode of use;
• - Figure 2 is a sectional view along II-II of Figure 1;
• FIG. 3 is a longitudinal sectional view, along III-III of Figure 5, of a first embodiment of the invention, with the net in the folded position;
• FIG. 4 is a similar view, but with the net in the deployed position
• FIG. 5 is a plan view, partially in section, along IV-17 of Figure 3;
• - Figure 6 is a sectional view according to VI-VI of Figure 4;
• FIG. 7 is a longitudinal sectional view of a second alternative embodiment of the invention, with the net in the folded position;
• - Figure 8 is a similar view but with the net in the deployed position;
• FIG. 9 is a similar view may s with f i l and in p o s i ti on re-closed;
• FIG. 10 is an elevational view, in section along X-X of Figure 11 of a third alternative embodiment of the invention.
• FIG. 11 is a plan view along XI-XI of Figure 10;
• Figure 12 is a detail view of Figure 10;
• FIG. 14 is a plan view of an assembly of several of the devices in FIGS. 10 and 11.
• a raft 1 shown floating a. the surface of the sea, comprises a flexible ring 2 produced in the form of an inflatable tube. In the central part of the raft is stretched a net 3 and, under this net is placed a sheet of rubber 4.
• This leaf has a certain opacity, seen from the breast of water, relative to the surface of the sea around the ring, and it has a certain concavity upwards, so as to give the fish the illusion of a ship hull.
• Calls 5 are fixed on the net 3.
• the calls are sound, light and olfactory.
• the former are supplied with electrical energy only from a wave buoy (not shown).
• An adjustable television camera 6 is suspended from the net 3 and arranged to observe the area located under the raft. It is connected by radio, via an antenna 7, to a receiver located in the accompanying ship 8. It is supplied with electrical energy in the same way as the calls.
• the vessel 8 anchors the raft 1 under which the tuna tend to gather. This gathering is observed using the camera 6, then, when it is deemed sufficient, an auxiliary ship 9 deploys around the raft a net 11, such as a seine, extending vertically in the water. Then, the auxiliary vessel pulls on a cable threaded on the lower edge of this net to restrict the area encircled and close the lower part of the net.
• a raft 101 is formed by an inflatable flexible ring 102 surrounding a net 103 furnished with calls 105 and a rubber sheet 104.
• an adjustable camera 106 communicating, via an antenna 107, with a receiver located on an accompanying ship.
• a cylindrical thread 111 has its upper edge fixed to the ring 102 by these detachable hooks operating by electromagnets, so as to allow desol idarisation of the thread and the ring.
• the net carries, on its upper edge, a number of floats 112 allowing it to float when it is detached from the ring.
• Poles 113 formed by steel downspouts are fixed under the ring 2 by their ends so as to constitute a bell cage under the ring.
• a ballast 114 is spun at the crossing point of these arches.
• the net 111 carries rings threaded onto these arches so as to be able to completely envelop the bell formed by the arches by trapping the fish (FIG. 4).
• each rod has its ends sliding on two neighboring arches and it is in two parts joined by a joint 116.
• these rods force the net to form folds 117 ( Figure 4) which avoid puckering.
• Weights 118 attached to the articulation points 116 ensure that the folds form towards the outside of the cage.
• the texture of the net 111 is provided finer without its lower part.
• Retaining lugs 119 are provided on each arch 113 to prevent the re-assembly of the net once deployed.
• the ring of the net 111 is then detached by releasing the assembly hooks and it is re-assembled on board by l e r ep l iant before having the deflated air. It only remains to catch the fish contained in the bell which floats thanks to the 112 floats using a landing net.
• a raft 201 is formed of a flexible and inflatable ring 202 surrounding a net 203 and a rubber sheet 204.
• a cylindrical net 211 (FIG. 8) whose bottom edge is provided with weights 218. This fixing is removable, being carried out by means of hooks with electromagnetic control.
• the upper edge of the net 211 carries floats 212 so that float when the ring is separated from the net.
• a directional camera 206 is attached to the net 203 and arranged to transmit, via an antenna 207, an image of the area located under the raft to a receiver located on an accompanying ship.
• a cord 221 is threaded on the lower edge of the net 211 and has free ends so as to allow, by traction, the closing of the lower part of the net (FIG. 9).
• the raft is wet, then the concentration of the fish is observed using the camera 206.
• the concentration of the fish is observed using the camera 206.
• the lower edge of the net 211 is released, which unfolds according to the configuration in FIG. 2.
• Floats 302 are distributed around the periphery of the hexagon to form a floating ring.
• each straight float 331 At the end of each straight float 331 is fixed the end of a chain 313 extended by a cable 333, and the ends of its cables are united at a common point 334 which, in normal service, is located under the center of the device.
• the chains 313 and the cables 333 constitute guide hoops on which are threaded rings 335 fixed on a thread 336.
• each straight float 331 At the end of each straight float 331 is fixed a pulley 337 on which is engaged a traction cable 338 fixed by one end at a point around the edge of the net 336, and provided at its other end with a counterweight 339.
• Each traction cable 338 carries, towards its end carrying the counterweight 339, a ring 341 engaged on a bolt 342 of a lock 343 (FIG. 12).
• This lock itself carries a ring 344 by which it is fixed to the float 331.
• the bolt 342 is integral with a pneumatic cylinder 345 connected by a pipe 346 to a bottle of compressed air 347.
• the counterweights 339 being in the high position, it is thus possible to remote control the simultaneous retraction of all the bolts, which causes the deployment of the net and the capture of the fish.
• An axial cable 348 is attached to the junction point 334 of the cables 333, to give an adequate shape to the capture volume. This cable is also used to raise the net full of fish. Once the net is brought back on board the accompanying vessel, it is emptied by the known process of artificial tears.
• Counterweights 339 s are fitted with rollers 349 ( Figure 13), which facilitates maneuvers on the deck of the ship.
• FIG. 14 In order to exploit a large school of fish, a certain number of hexagonal devices are assembled according to a regular paving 350 (FIG. 14). A common compressed air bottle 351 is then used. A pressure gauge measures the pressure of the compressed air at the outlet of the bottle and, each time this pressure reaches a predetermined threshold, opens the pipe relating to one of the hexagons. In this way, once the deployment of one of the nets has started, the deployment of the others follows sequentially.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Environmental Sciences (AREA)
• Animal Husbandry (AREA)
• Biodiversity & Conservation Biology (AREA)
• Mechanical Means For Catching Fish (AREA)
• Artificial Fish Reefs (AREA)
• Farming Of Fish And Shellfish (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9255846

Family Applications (1)

Country Status (16)

Cited By (2)

Families Citing this family (4)

Citations (6)

• 1981
  • 1981-03-04 FR FR8104289A patent/FR2501003B1/fr not_active Expired
• 1982
  • 1982-02-06 OA OA57619A patent/OA07023A/xx unknown
  • 1982-02-17 IN IN131/DEL/82A patent/IN157693B/en unknown
  • 1982-02-19 AU AU80619/82A patent/AU8061982A/en not_active Abandoned
  • 1982-02-25 GR GR67414A patent/GR75508B/el unknown
  • 1982-02-25 EP EP82900637A patent/EP0073779A1/fr not_active Withdrawn
  • 1982-02-25 WO PCT/FR1982/000033 patent/WO1982002996A1/en not_active Application Discontinuation
  • 1982-02-25 ZA ZA821242A patent/ZA821242B/xx unknown
  • 1982-03-02 BR BR8201053A patent/BR8201053A/pt unknown
  • 1982-03-02 MA MA19604A patent/MA19399A1/fr unknown
  • 1982-03-03 PT PT74524A patent/PT74524A/pt unknown
  • 1982-03-03 JP JP57033715A patent/JPS57208934A/ja active Pending
  • 1982-03-03 ES ES510101A patent/ES8303020A1/es not_active Expired
  • 1982-03-03 DK DK92482A patent/DK92482A/da not_active Application Discontinuation
  • 1982-03-03 NO NO820663A patent/NO820663L/no unknown
  • 1982-03-04 IT IT8219959A patent/IT1210861B/it active

Patent Citations (6)

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