Trawl system for extracting organisms from a fish cage

Abstract

The invention describes a trawl system (1) for extraction of organisms from a fish cage (2). The system comprises a pulling system (3) arranged to produce a pull substantially parallel to an outer wall (4) of the cage (2), and a trawl (5). The trawl comprises a trawl frame (6), pulling lines (26) arranged to connect the trawl frame (6) to the towing system (3) and a trawl bag (8) which is attached to the trawl frame (6). The invention is characterized by the fact that a trawl door (9) is hinged to one side of the trawl frame (6) and where the trawl door is configured to be pulled along the outer cage wall (4) of the cage (2) when the trawl is pulled by the pulling system.

Description

[0001] Title: Trawl system for extracting organisms from a fish cage

[0002] Description

[0003] Technical field of the invention

[0004] The invention concerns the breeding of fish in cages. More specifically, the invention relates to a trawl system for fishing out organisms from a cage.

[0005] Background

[0006] Salmon lice are a known problem in the fish farming industry and cleaning fish of various types have been used to combat salmon lice. As the use of cleaning fish has increased, the requirements for the treatment of cleaning fish have also become stricter. The Norwegian Food Safety Authority has a requirement to extract lumpfish before treatment against lice and during slaughter deliveries.

[0007] The aquaculture industry works to meet these requirements in an efficient way and several players hire expensive services to extract the cleaning fish. There is a need for a simpler and more efficient solution that breeders themselves can use to extract the cleaning fish.

[0008] Fulfillment of the requirement to extract the cleaning fish will be central to the industry being able to continue using cleaning fish in its facilities. New regulations are being drawn up where breeders can be fined if the requirements are not met.

[0009] Another problem in the aquaculture industry is sick fish. To maintain fish welfare, it is desirable to fish out the sick fish as soon as possible. As of today, there is also no good equipment on the market to extract large quantities of sick salmon from a cage.

[0010] Summary of the invention

[0011] The invention describes a trawl system for extracting organisms from a cage comprising a pulling system arranged to produce a pull substantially parallel to an outer wall of the cage and a trawl. The trawl comprises a trawl frame, pulling lines arranged to connect the trawl frame to the towing system and a trawl bag attached to the trawl frame. The trawl system is characterized by a trawl door which is hinged to one side of the trawl frame and which is configured to be pulled along the outer wall of the cage when the trawl is pulled by the pulling system.

[0012] In one embodiment of the invention, the trawl is provided with a trawl door stopper which prevents the trawl door from swinging past a maximum angle ambetween a plane through the trawl door and a plane through the trawl frame.

[0013] In one embodiment of the invention, the trawl door is hinged to the trawl frame with trawl door hinges and the trawl door stopper is integrated into at least one trawl door hinge, which comprises a door hinge arm and a frame hinge arm arranged so that the door hinge arm hits the trawl frame 6 at the maximum angle am.

[0014] In yet another embodiment of the invention, the trawl door stopper comprises a door stopper rope that runs from the pulling rope or the trawl frame to a side of the trawl door that is not hinged to the trawl frame

[0015] In yet another embodiment of the invention, the trawl door comprises a trawl door frame with a trawl door panel stretched out between the sides of the trawl door frame to guide the organisms towards the trawl bag.

[0016] In yet another embodiment of the invention, the trawl bag is attached to the trawl door in addition to being attached to the trawl frame and where the trawl door frame does not have a trawl door panel stretched out between the sides, so that all the organisms go straight into the trawl bag.

[0017] In yet another embodiment of the invention, the trawl door frame has the shape of a rectangle.

[0018] In yet another embodiment of the invention, the trawl door frame has the shape of a trapezoid with two right angles where the side between the two right angles is hinged to the trawl frame.

[0019] In yet another embodiment of the invention, the trawl door frame comprises an outer side with a shape similar to the outer groove wall of the cage.

[0020] In another embodiment of the invention, an upper side of the trawl frame is provided with a floating unit.

[0021] In yet another embodiment of the invention, the side of the trawl door which abuts the outer wall of the cage is provided with rollers arranged to roll along the outer wall to reduce friction.

[0022] Brief description of the figures

[0023] In order to improve the understanding of the invention, some figures have been attached where the same feature has the same reference number in the different figures.

[0024] Fig. 1 shows an embodiment of the trawl system for fishing out organisms from a cage.

[0025] Fig. 2 shows an embodiment of a trawl for the trawl system.

[0026] Fig. 3a shows an embodiment of a trawl bag which is only attached to the trawl frame.

[0027] Fig. 3b shows an embodiment of a trawl bag which is attached to both the trawl frame and the trawl door.

[0028] Fig. 4 shows an embodiment of the trawl system where the trawl door is biased against an outer cage wall of the cage.

[0029] Fig. 5 shows an embodiment of the door stopper which is integrated in the trawl door hinge. Fig. 6a and b show a trapezoidal and a rectangular design of the trawl door.

[0030] Detailed description

[0031] This text describes a trawl system 1 for fishing out / extr action of organisms from a cage 2. The trawl system is described as if it were in a working situation in a cage, that is to say that the position and directions refer to such a situation. The organisms referred to can include cleaning fish, plankton and salmon. The cage will typically be a traditional round cage with a circular fish cage, but can also have a different shape and, for example, be a closed cage.

[0032] The trawl system comprises a trawl 5 and a pulling system 3 which pulls the trawl. The pulling system 3 is arranged to produce a pull mainly parallel to an outer wall 4 of the cage 2. In one embodiment of the pulling system 3, this is achieved by a pulling rope 7 which is attached by means of a plurality of release hooks 17 to a float collar to the cage or to a handrail that is attached to the float collar. Preferably, the release hooks 17 are attached close to the water surface. Typically, the length of the pulling rope will be slightly longer than the circumference of the cage. One end of the pulling rope is attached to a towing unit 18, e.g. in the form of a capstan 24 or winch and the other end is attached to the trawl, preferably with a spindle at each end to prevent the rope from twisting. The winch / capstan 24 is started and a first operator releases each release hook as the trawl approaches the release hook 17.

[0033] In one embodiment the pulling rope is fastened together at the ends to form a loop and in an alternative embodiment the pulling rope is not fastened together at the ends and the rope is pulled through the release hooks by a winch. Often the trawl has to be driven several times around the cage to achieve the desired result and therefore it is advantageous that the pulling rope 7 is arranged as a loop so that the process can be repeated immediately. In cases where a loop is used, an operator (preferably a second operator) can put the release hook back on the pulling rope when the trawl has passed.

[0034] In an alternative embodiment of the pulling system 3 (not shown), the release hooks 17 are replaced by pulleys 19 which preferably comprise a spring-loaded mechanism that holds the rope in the pulley if the pull in the pulling rope is absent or has a large downwardly directed component.

[0035] In yet another alternative embodiment (not shown), the pulling system comprises a rail that runs around the periphery of the cage and where a pulling unit runs in the rail and pulls the trawl with it.

[0036] The trawl system 1 further comprises a trawl 5. The trawl 5 in turn comprises a trawl frame 6 which is preferably rectangular. Other shapes are conceivable, but at least one of the sides must be approximately straight in order to be able to cooperate with a trawl door 9 which is hinged on the trawl frame 6. The trawl further comprises pulling lines 26 which attach the trawl 5 to the towing system 3. The trawl comprises, in one embodiment shown in figs 2 and 3a, a trawl pulling rope 35 which attaches the trawl frame 6 to the towing system 3. The towbars 26 of the trawl can also be directly attached to the towing system 3. If the towing system 3 comprises a pulling rope 7, the pulling lines 26 can be attached directly to the pulling rope 7 or the pulling lines can be attached to the trawl pulling rope 35 which in turn is attached to the pulling rope 7 as indicated in fig.1 where the pulling rope is also arranged as a loop. The trawl further comprises a trawl bag 8 which is attached to the trawl frame 6. Preferably there is a fish lock 19 in the trawl bag to prevent fish escaping from the trawl bag when the trawl system is used on fish.

[0037] The trawl system further comprises a hinged trawl door 9 which is attached to one side of the trawl frame 6, where the trawl door 9 is configured to be pulled along the outer wall 4 of the cage 2 when the trawl is pulled by the pulling system to guide the organisms into the trawl bag.

[0038] In one embodiment, the trawl 1 is provided with a trawl door stopper 10 which prevents the trawl door 9 from swinging past a maximum angle amwhich describes an angle between a plane through the trawl door and a plane through the trawl frame 6. The angle a is 0 when the trawl door covers parts of the opening of the trawl frame 6 and 180 degrees when the trawl door 9 stands straight out in extension of a plane through the trawl frame and approximately perpendicular to the outer wall 4 of the cage 2. The angle of the trawl door 9 in fig. 4 is approx. 135 degrees. The maximum angle amis preferably between 100 and 170 degrees, more preferably between 120 and 150 degrees. The inventor has achieved good results with a maximum angle amof 135 degrees.

[0039] Figures 5a and b show a preferred embodiment of the trawl door stopper 10 from the side and from above. In this embodiment, the trawl door stopper is integrated into a trawl door hinge 28. The trawl door 9 is hinged on the trawl frame 6 by means of the trawl door hinge 28 which comprises a door hinge arm 36 and a frame hinge arm 37 configured so that the door hinge arm 36 hits the trawl frame 6 at the maximum angle am.

[0040] The purpose of the trawl door 9 is to catch all the fish or organisms that stand with their heads against the outer wall of the net 4. This is a position that cleaning fish and sick or hurt fish often take. The hinged trawl door is able to compensate for an alternating distance between the trawl frame and the outer wall of the cage. This distance changes with waves, current, pulling force and pulling direction.

[0041] In an embodiment shown in fig. 3b, the trawl door stopper 10 comprises a door stopper rope 12 which runs from the pulling rope 7 or the trawl frame 6 to a side of the trawl door 9 which is not hinged to the trawl frame 6.

[0042] Preferably, the trawl door 9 is biased with a pretension which presses the trawl door against the outer wall 4 of the cage 2. Biasing can be achieved by means of a spring between trawl frame 6 and trawl door 9. In a preferred embodiment shown in fig. 4, the pretension is achieved by an elastic rope 21 which is fixed at the bottom and / or top of the trawl door frame 13 and trawl frame 6, respectively, by means of fastening brackets 22 and guided by means of guide brackets 23. The elastic rope 21 is attached to the back of the trawl door 9 and the trawl frame 6. That is, downstream for the trawl frame and trawl door now that it is pulled through the water. In this way, the desired effect is achieved where the trawl door compensates for the alternating distance between the trawl frame 6 and the outer cage wall 4 when the trawl 5 is pulled forward by the pulling system 3. In a preferred embodiment, the trawl door 9 comprises a trawl door frame 13 with a trawl door panel 27 stretched out between the sides of the trawl door frame 13 to guide the organisms towards the trawl bag 8. The trawl door can also be a plate of wood or other materials. It is an advantage that the trawl door has relatively neutral buoyancy and if the size of the organisms allows it, it is an advantage that the trawl door panel 27 is made of a mesh to reduce resistance in the water.

[0043] Reference is now made to fig. 3b. In an embodiment of the trawl system where the organism to be taken out of the cage is of small size, e.g. plankton, the trawl bag 8 is attached to the trawl door 9 in addition to being attached to the trawl frame 6. The reason for this is that if the trawl door panel 27 in the trawl door is very finely meshed, the resistance in the water will be as great as when using a compact plate. It is therefore an advantage that the trawl door frame 13 does not have a trawl door panel 27 stretched out between the sides when removing plankton or small organisms.

[0044] Fig. 2 also shows a lifting strap 31 that goes around the trawl bag 8 right in the middle of the bag and an associated lifting ring 32 which is preferably also attached to the trawl frame 6 by means of a frame lifting strap 34 and to the lifting ring by means of a strap joint 33.

[0045] As shown in fig. 6b, the trawl door can be rectangular in design, that is to say that the trawl door frame 13 has the shape of a rectangle. In another embodiment shown in fig. 6a, the trawl door 13 is shaped like a trapezoid with two right angles where the side between the two right angles is hinged to the trawl frame 6. This can also be called a truncated triangle. The trawl door must be adapted to the individual cage because each type of cage has its own distinctive angle on the upper part of the outer wall, which is the area where most organisms are located.

[0046] In one embodiment of the trawl system, an upper side of the trawl frame 6 is provided with a floating unit 15 shown in fig. 2 and fig. 3a. The floating unit 15 helps the trawl to lie horizontally in the water so that the trawl door 9 gets the corect angle to the outer wall of the cage.

[0047] Preferably, the side of the trawl door 9 which abuts the outer wall 4 of the cage 2 is provided with rollers 16 arranged to roll along the outer wall 4 to thereby reduce friction.

[0048] Reference list

[0049] 1 Trawl system

[0050] 2 Fish cage

[0051] 3 Pulling system

[0052] 4 Outer cage wall

[0053] 5 Trawl

[0054] 6 Trawl frame

[0055] 7 Pulling rope

[0056] 8 Trawl bag

[0057] 9 Trawl door

[0058] 10 Trawl door stoppers

[0059] 13 Trawl door frame

[0060] 14 Netting

[0061] 15 Floating unit

[0062] 16 Rollers

[0063] 17 Release hook

[0064] 18 Pulling unit

[0065] 19 Fishing lock

[0066] 20 Cage wall

[0067] 21 Elastic rope

[0068] 22 Bracket for fastening elastic rope

[0069] 23 Bracket to hold rope knitting in place

[0070] 24 Capstan on a work boat

[0071] 25 Work boat

[0072] 26 pulling lines

[0073] 27 Trawl door panel

[0074] 28 Trawl door hinge

[0075] 29 Knot at the end of the trawl bag

[0076] 30 Swivel / coupling point

[0077] 31 Lifting strap around the trawl bag

[0078] 32 Lifting rings

[0079] 33 Strap joint

[0080] 34 Lifting strap that goes up to the trawl frame 6

[0081] 35 Trawl pulling rope

[0082] 36 Door hinge alarm

[0083] 37 Frame hinge arm

Claims

CLAIMS1. A trawl system (1) for fishing out organisms from a cage (2) comprising: a pulling system (3) arranged to produce a pull substantially parallel to an outer groove wall (4) of the cage (2), and a trawl (5) comprising: a trawl frame (6), pulling lines (26) arranged to connect the trawl frame (6) to the draw system (3), a trawl bag (8) which is attached to the trawl frame (6), characterized by a trawl door (9) which is hinged to one side of the trawl frame (6) and which is configured to be pulled along the outer groove wall (4) of the cage (2) when the trawl (5) is pulled by the pulling system.

2. Trawl system according to claim 1 where the trawl (5) is provided with a trawl door stopper (10) which prevents the trawl door (9) from swinging past a maximum angle am between a plane through the trawl door and a plane through the trawl frame.

3. Trawl system according to claim 2 where the trawl door (9) is hinged to the trawl frame (6) with trawl door hinges (28) and the trawl door stopper (10) is integrated into at least one trawl door hinge (28), which comprises a door hinge arm (36) and a frame hinge arm (37) ) arranged so that the door hinge arm (36) hits the trawl frame (6) at the maximum angle am.

4. Trawl system according to claim 3 where the maximum angle amis preferably between 100 and 170 degrees, more preferably between 120 and 150 degrees.

5. Trawl system according to claim 2 where the trawl door stopper (10) comprises a door stopper rope (12) which runs from the pulling rope (7) or the trawl frame (6) to a side of the trawl door (9) which is not hinged to the trawl frame (6).

6. Trawl system according to any of the preceding claims where the trawl door (9) is biased against the outer groove wall (4).

7. Trawl system according to any of the preceding claims where the trawl door (9) comprises a trawl door frame (13) with a trawl door panel (27) stretched out between the sides of the trawl door frame (13) to guide the organisms towards the trawl bag (8).

8. Trawl system according to any one of claims 1-6 where the trawl bag (8) is also attached to the trawl door (9) and where the trawl door frame (13) does not have a trawl door panel (27) stretched out between the sides.

9. Trawl system according to any of the preceding claims, where the trawl door frame (13) has the shape of a rectangle.

10. Trawl system according to any one of claims 1-6 where the trawl door frame (13) has the shape of a trapezoid with two right angles where the side between the two right angles is hinged to the trawl frame (6).

11. Trawl system according to any one of the preceding claims, where an upper side of the trawl frame is provided with a floating unit (15).

12. A trawl system according to any one of the preceding claims where the side of the trawl door which abuts the outer wall of the cage is provided with rollers (16) arranged to roll along the outer wall (4) to thereby reduce friction.

Images