Submersible system for aquaculture and a method for feeding and crowding of fish within the system

Abstract

A facility (1) for farming fish, wherein the facility (1) comprises: - a floating central unit (2); and - a plurality of submersible cages (3), wherein each cage (3) comprises one or a plurality of sections (4). Each section (4) comprises a closed, water-passable enclosure for the fish. Each section (4) is provided with an air dome in an upper portion. The cage (3) provided with a buoyancy means. Each section (4) is from a lower portion connected to a detached buoy (6) by at least one hose connection (5). The buoy (6) is internally provided with at least one container connected to the at least one hose connection (5). The buoy (6) is externally provided with at least one of an inlet and an outlet, wherein at least one of the inlet and the outlet is connected to the at least one container. Also described is a method for moving fish from the lower portion of the section.

Description

[0001] NIPO

[0002] 1

[0003] SUBMERSIBLE SYSTEM FOR AQUACULTURE AND A METHOD FOR FEEDING AND CROWDING OF FISH WITHIN THE SYSTEM

[0004] The invention concerns a facility for farming fish. More specifically, the invention concerns a facility comprising a floating central unit and fully submersible cages distributed around the central unit. Each cage is provided with one section or a plurality of sections. Each section comprises a closed, water-passable enclosure for the fish. Each section is from its lower portion connected to a detached buoy by at least one hose connection. The buoy is internally provided with at least one container connected to the at least one hose connection. One of the hose connections is a fish transfer hose arranged to guide fish from the lower portion of the section to the buoy. The fish is gently crowded inside the section by raising the section slowly vertically, so that the section essentially is above a water surface and the fish is crowded together in the lower portion of the section. In an alternative embodiment, the section may be provided with a crowding element. When the crowding element is activated, it covers the cross-section of the section in the upper portion of the section. The crowding element is guided slowly downwards in the section so that the fish is crowded together in the lower portion of the section.

[0005] Farming of fish, especially salmonoids, has traditionally been done in net pens that float on the water surface. Each net pen comprises an enclosure formed by a net. The enclosure is closed in such a way that the fish may not escape from the enclosure. The enclosure is open in such a way that water may flow through the enclosure. Such net pens are relatively simple constructions. A disadvantage is that the fish in the net pen are exposed to parasites, such as salmon lice, that drift with the water. Net pens such as these are exposed to waves and wind and are therefore placed in relatively protected locations along a coastline.

[0006] Use of closed net pens floating on the water surface is known. Such net pens are closed in such a way that the wall and the bottom are liquid-tight. Parasites are thereby prevent-

[0007] Rectified sheet NIPO

[0008] 2 ed from drifting in to the fish. Such net pens are supplied with fresh, oxygenic water through pipes that have an inlet at a water depth below where one may expect parasites to reside. Such closed net pens are also exposed to waves and wind.

[0009] Use of net pens that may be submerged fully under the water surface is also known. In that way, the net pen is lowered under the waves, and the net pen is not much affected by waves and wind. Such net pens are formed by nets that encircle the entire net pen. The net pen may be lowered by being fastened to a sea floor via a wire or other cable and by the net pen being lowered and raised in the water column by a winch or similar. Salmo- noids are so-called physostomous fish, having an open channel between the alimentary canal and the gas bladder. If the plan is to have the net pen submerged over a longer period, it is necessary to arrange an air pocket at the top of the net pen so that salmonoids may gulp air there. Such a net pen is open in such a way that water may flow through the net pen. The net pen is lowered to a depth where it is assumed that there are no parasites in the water. Such net pens usually have alternatives for collect deceased fish from a central funnel at the bottom of the net pen. There are limited possibilities to collect uneaten feed, faecal matter and other debris. Some of this will follow the water flow out of the net pen.

[0010] Farming fish in land-based facilities is also known. Land-based facilities avoid problems related to parasites in the water, bad weather and access to air for salmon fish. Land- based facilities require large investments and are dependent upon advanced purification technology to maintain water quality in the water being recycled in the facility. Land-based facilities have many and large pumps to move all the water in the tanks.

[0011] The purpose of the invention is to remedy or reduce at least one of the disadvantages of prior art, or at least provide a useful alternative to prior art.

[0012] The purpose is fulfilled by the features specified in the description below and the subsequent patent claims.

[0013] A facility for farming fish according to the description is suitable to be operated offshore or in locations closer to the coast where wave height may be great, so-called exposed locations.

[0014] The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

[0015] Rectified sheet NIPO

[0016] 3

[0017] In a first aspect, the invention concerns a facility comprising a floating central unit. The central unit may be a so-called semi-submersible unit. This means that the central unit may be raised and lowered in the sea by changing the buoyancy of floating bodies, such as for example of pontoons, but the central unit is not to be submerged. The central unit is anchored in a mooring system.

[0018] The facility comprises a plurality of cages on the outside of the central unit. Each cage may be fully submerged. Each cage comprises one or a plurality of sections. Each section comprises a closed enclosure for fish. The closed enclosure comprises a net that keeps the fish inside the section and that allows seawater to flow through the section.

[0019] Each section is at its upper portion provided with an air dome so that physostomous fish, such as salmonoids, has access to air when the cage is fully submerged. Each air dome may be provided with air via an air hose. The central unit may be provided with a facility to provide air to the air hoses.

[0020] The central unit may comprise a so-called umbilical connection, which may provide each cage or each section with air and other fluids. The umbilical connection may comprise electrical cables for energy transfer and cables for transfer of steering signals and sensor signals.

[0021] Each cage is provided with a buoyancy means. The buoyancy means may be an adjustable buoyancy means. Adjustable means that the buoyancy means may be filled with a gas, such as air, to increase the buoyancy, or with a liquid, such as water, to reduce the buoyancy. The buoyancy means may comprise a combination of adjustable buoyancy means and buoyancy means with fixed buoyancy. Each cage may be a truss construction or a frame comprising pipes of steel. The truss construction may make up the buoyancy means by taking advantage of cavities in the truss construction to be a buoyancy means with fixed buoyancy, and to take advantage of other cavities in the truss construction to be a buoyancy means with adjustable buoyancy. The truss construction may make up a part of the buoyancy means.

[0022] Each section is from a lower portion connected to a detached buoy by at least one hose connection. The buoy may be anchored. The buoy may float freely relative to the central unit and the cage. The buoyancy body may be provided with means to adjust the buoyancy.

[0023] Rectified sheet NIPO

[0024] 4

[0025] The buoy is internally provided with at least one container connected to the at least one hose connection. The buoy is externally provided with at least one of an inlet and an outlet, wherein at least one of the inlet and the outlet is connected to the at least one container.

[0026] The buoy may internally be provided with a plurality of containers. The plurality of containers may be of the same type or have the same function. The plurality of containers may be of different types or have different functions. The plurality of containers may comprise a mix of containers of different types or with different functions and a plurality of containers of the same type and with the same function.

[0027] The central unit may be a semi-submersible construction. The cage may be arranged to be able to be raised and lowered vertically relative to the central unit in a water column.

[0028] The buoyancy means may comprise a buoyancy body in a lower portion of the cage. The buoyancy means may comprise the truss construction and the buoyancy body.

[0029] The at least one container may comprise a container for deceased fish. The container for deceased fish may be connected to a hose for deceased fish. The container for deceased fish may be connected to an extraction opening arranged to be connected to a vessel.

[0030] The at least one container may comprise a feed container. The feed container may be connected to a feed hose. The feed container may be connected to an inlet arranged to be connected to a vessel.

[0031] The buoy may be provided with a feeding system arranged to supply feed to each section through the feed hose. The buoy may be provided with a plurality of feed containers. The feeding system may be arranged to choose between feed from several feed containers and optionally supply feed to each section from the chosen feed container. The feed may be a fish feed.

[0032] Each section may be connected to the buoy by a fish transfer hose. The buoy may be provided with a fish transfer connection that may be connected to a vessel arranged to supply fish from the vessel to the buoy, or to a vessel arranged to receive fish from the buoy.

[0033] The buoy may be provided with an internal fish distribution system. The fish distribution system may be connected to a plurality of fish transfer hoses. The fish distribution system may be arranged to guide fish from an optional first section through a first fish transfer

[0034] Rectified sheet NIPO

[0035] 5 hose and to the fish distribution system, and from the fish distribution system through an optional second fish transfer hose and to a second section. The fish distribution system may be arranged to distribute fish from the vessel through the fish distribution system and to an optional section through the fish transfer hose.

[0036] A plurality of hoses may connect the buoy to each section. The buoy may comprise a plurality of internal containers. The buoy may comprise a plurality of containers for deceased fish. The buoy may comprise a plurality of feed containers.

[0037] The at least one container for deceased fish may be connected to at least one of the sections by a hose for deceased fish. Each section may be connected to the hose for deceased fish. Alternatively, there may be one hose for deceased fish for each section. The hoses for deceased fish may lead out into the same container for deceased fish. Alternatively, there may be one container for deceased fish for each hose for deceased fish. It is advantageous for there to be as many containers for deceased fish as there are sections. The at least one container for deceased fish may be connected to an extraction opening that may be connected to a vessel arranged to pump deceased fish from the container for deceased fish and to the vessel.

[0038] The at least one feed container may be connected to at least one of the sections by a feed hose. The at least one feed container may be connected to each section by separate feed hoses. The buoy may be provided with a feeding system that supplies feed to each section through the at least one feed hose. The feeding system may be arranged to choose between feed from several feed containers and optionally supply feed to each section from the chosen feed container. The at least one feed container is provided with an inlet, which may be connected to a vessel arranged to supply feed from the vessel to the at least one feed container.

[0039] Fish in sections of a cage may be gently crowded together by slowly raising the cage so that the cage essentially is above a water surface. Thereby, the fish will be gathered in the lower portion of the sections. From the lower portion of the section the fish is transferred to the buoy through the fish transfer hose. The fish may be transferred by means of a known fish pump connected to the fish transfer hose. The fish pump may be positioned inside the buoy.

[0040] In an alternative embodiment, each section is internally provided with a crowding element. When the crowding element is activated, it will first be positioned in the upper portion of the section and cover the cross-section of the section. Thereafter, the crowding element is

[0041] Rectified sheet NIPO

[0042] 6 guided slowly downwards in the section so that the fish is gently crowded together in the lower portion of the section. From the lower portion of the section the fish is transferred to the buoy through the fish transfer hose. The fish may be transferred by means of a known fish pump connected to the fish transfer hose. The fish pump may be positioned inside the buoy.

[0043] Each cage may, independently of each other, be raised and lowered vertically in relation to the central unit by means of the adjustable buoyancy means of each cage. The central unit comprises the necessary equipment to run the facility for farming fish. The central unit floats in a stable manner. The central unit provides support to the surrounding cages.

[0044] The facility for farming fish is a facility where the closed, water-passable enclosures for fish are submerged essentially during the growth period of the fish. The depth at which the enclosures are positioned, may be adjusted and adapted to local wave height. The facility is especially advantageous in that the fish may be removed from the enclosures by a gentle crowding of fish. The crowding of the fish may be done downwards towards a lower portion of the enclosure, such as the bottom of the enclosure. The fish may be removed from the enclosure by the lower portion of the enclosure.

[0045] The facility for farming fish increases animal welfare by mimicking natural conditions and by reducing stress when crowding fish, since the fish is crowded slowly downward without the use of e.g. a sweep net.

[0046] The buoys make it possible for vessels, such as fish carriers and feed carriers, to service the facility without docking at the central unit and without docking at the fish enclosures. The risk of damaging the facility is thereby reduced.

[0047] In a second aspect, the invention concerns a method for farming fish. The method comprises:

[0048] - providing a facility for farming fish as described previously;

[0049] - transferring fish to at least one of the sections;

[0050] - transferring fish from the lower portion of the at least one section to the buoy through the fish transfer hose by one of:

[0051] - raising the section vertically so that the section essentially is above a water surface and the fish is crowded together in the lower portion of the section; and

[0052] - providing a crowding element to the section, activating the crowding element so that it covers the cross-section of the section in the upper portion of the section, and guiding the

[0053] Rectified sheet NIPO

[0054] 7 crowding element downwards in the section so that the fish is crowded together in the lower portion of the section.

[0055] The fish may be transferred to the vessel through the fish transfer connection.

[0056] Feed may be transferred from a vessel to the at least one feed container, and the feeding system may distribute feed to an optional section through the feed hose.

[0057] Deceased fish may be transferred from one section to the at least one container for deceased fish through the hose for deceased fish.

[0058] Fish may be transferred from a section to another section by fish being guided from an optional first section through the first fish transfer hose to the fish distribution system, and from the fish distribution system through an optional second fish transfer hose to the second section.

[0059] The fish distribution system may distribute fish from a vessel through the fish transfer connection to an optional section through the fish transfer hose.

[0060] A person skilled in the art will understand that the fish is fed the feed in the facility. For example, the fish may be a salmonoid. The fish may be fed until it has reached slaughter weight. A person skilled in the art will also understand that the facility may be used to feed the fish until they reach a desired size, and that the fish in a section is thereafter distributed to several sections so that the fish may be fed until they reach another desired size, such as a slaughter weight.

[0061] In the following, an example is described of a preferred embodiment, which is illustrated in the attached drawings, wherein:

[0062] Fig. 1 shows a side sketch of a farming facility for fish with a floating unit and a number of submersible cages for farming fish, wherein the cages are coupled to the central unit;

[0063] Fig. 2 shows, at a different scale, a sketch in perspective of the farming facility shown in Figure 1 ;

[0064] Fig. 3 shows, at a different scale, a top sketch of the farming facility shown in Figure 1 ;

[0065] Rectified sheet NIPO

[0066] 8

[0067] Fig. 4 shows, at a different scale, a sketch in perspective of the farming facility, where fish are crowded together in a lower portion of a section in a cage that is raised essentially above a water surface, and the figure also shows a vessel servicing the farming facility; and

[0068] Fig. 5 shows, at a different scale, a schematic cross-section through a buoy.

[0069] All position indicators refer to the position shown in the figures.

[0070] The same or corresponding elements are indicated with the same reference number in the figures. For the sake of clarity some elements may not have reference numbers in some of the figures.

[0071] A person skilled in the art will understand that the figures are only principle drawings. The relative ratio between individual elements may also be distorted.

[0072] In the figures, reference number 1 refers to a facility for farming fish. The facility 1 comprises a floating central unit 2. The central unit 2 is shown as a semi-submersible construction 21. The facility 1 comprises a plurality of submersible cages 3. Each cage 3 comprises one or a plurality of sections 4. Each section 4 comprises a closed enclosure 41 for fish 7. Each section 4 is provided with an air dome 42 in an upper portion 40.

[0073] The closed enclosure 41 comprises a net that keeps the fish inside the section 4 and that allows seawater to flow through the section 4. The closed enclosure 41 may comprise a net in the ceiling, walls and bottom.

[0074] Each section 4 is at a lower portion 49 connected to a detached buoy 6 by at least one hose 5. Each section 4 may be connected to the buoy 6 by a hose for deceased fish 52. Each section 4 may be connected to the buoy 6 by a feed hose 54. Each section 4 may be connected to the buoy 6 by a fish transfer hose 57.

[0075] Two sections 4 in one cage 3 may be connected to a common hose for deceased fish 52. Three sections 4 in one cage 3 may be connected to a common hose for deceased fish 52. All sections 4 in one cage 3 may be connected to a common hose for deceased fish 52. Two sections 4 in one cage 3 may be connected to a common feed hose 54. Three sections 4 in one cage 3 may be connected to a common feed hose 54. All sections 4 in one cage 3 may be connected to a common feed hose 54. Two sections 4 in one cage 3 may be connected to a common fish transfer hose 57. Three sections 4 in one cage 3

[0076] Rectified sheet NIPO

[0077] 9 may be connected to a common fish transfer hose 57. All sections 4 in one cage 3 may be connected to a common fish transfer hose 57.

[0078] Each buoy 6 is internally provided with at least one container 61. The at least one container 61 is connected to at least one hose 5. Each buoy 6 may be internally provided with at least one container for deceased fish 62. Each buoy 6 is internally provided with at least one feed container 64.

[0079] Each buoy 6 may be internally provided with a feeding system 65. The feeding system 65 may be arranged to choose between feed (not shown) from several feed containers 64 and optionally supply feed to each section 4 from the chosen feed container 64.

[0080] Each buoy 6 may be provided with a fish transfer connection 67 that may be connected to a vessel 8 arranged to supply fish 7 from the vessel 8 to the buoy 6, or to a vessel 8 arranged to receive fish 7 from the buoy 6. Each buoy 6 may be provided with an internal fish distribution system 68. The fish distribution system 68 may be connected to a plurality of fish transfer hoses 57. The fish distribution system 68 may be arranged to guide fish 7 from an optional first section 4 through a first fish transfer hose 57 to the fish distribution system 68, and from the fish distribution system 68 through an optional second fish transfer hose 57 to a second section 4. The fish distribution system 68 may be arranged to distribute fish 7 from the vessel 8 through the fish transfer connection 67 to an optional section 4 through the fish transfer hose 57.

[0081] Each buoy 6 is shown with an inlet 60 and an outlet 69. The inlet 60 may comprise a feed inlet 604. The feed may be a fish feed. The inlet 60 may comprise the fish transfer connection 67. The outlet 69 may comprise an extraction opening for deceased fish.

[0082] Each cage 3 comprises at a lower portion 39 a buoyancy body 31. The buoyancy body 31 may be provided with means (not shown) to adjust the buoyancy. The cage 3 and each section 4 in the cage 3 may be operated via an umbilical connection 23 between the central unit 2 and the cage 4. The umbilical connection 23 may be wound on a drum 25 on the central unit 2 so that the free length of the umbilical connection 23 may be adapted to the depth of the cage 3 in a water column 99. The umbilical connection 23 may comprise electrical cables for energy transfer and cables for transfer of steering signals and sensor signals.

[0083] Rectified sheet NIPO

[0084] 10

[0085] The air domes 42 may be supplied with air from the central unit 2 through the umbilical connection 23. The cage 3 is in an upper portion 30 shown with an air distribution system 27.

[0086] It should be noted that the embodiment illustrates the invention, but does not delimit it, and persons skilled in the art will be able to design many alternative embodiments without deviating from the scope of the attached claims. In the claims, the reference numbers in parenthesis shall not be considered delimiting.

[0087] The use of the verb "to comprise" and its different forms does not exclude the presence of elements or steps not mentioned in the claims. The indefinite articles "a" or "an" before an element do not exclude the presence of more such elements.

[0088] The fact that some features are specified in mutually different dependent claims does not indicate that a combination of these features cannot be used advantageously.

[0089] Rectified sheet

Claims

P a t e n t c l a i m s1. A facility (1) for farming fish (7), wherein the facility (1) comprises:- a floating central unit (2); and- a plurality of submersible cages (3), wherein each cage (3) comprises one or a plurality of sections (4), and wherein each section (4) comprises a closed, water- passable enclosure (41) for the fish (7), and wherein each section (4) is provided with an air dome (42) in an upper portion (40), c h a r a c t e r i z e d i n that:- the cage (3) is provided with a buoyancy means (33);- each section (4) is from a lower portion (49) connected to a detached buoy (6) by at least one hose connection (5);- the buoy (6) is internally provided with at least one container (61) connected to the at least one hose connection (5); and- the buoy (6) is externally provided with at least one of an inlet (60) and an outlet (69), wherein at least one of the inlet (60) and the outlet (69) is connected to the at least one container (61).

2. The facility (1) according to claim 1 , wherein the central unit (2) is a semisubmersible construction (21).

3. The facility (1) according to any of the preceding claims, wherein the cage (3) is arranged to be able to be raised and lowered vertically in relation to the central unit (2) in a water column (99).

4. The facility (1) according to any of the preceding claims, wherein the buoyancy means (33) comprises an adjustable buoyancy body (31) in a lower portion (39) of the cage (3).

5. The facility (1) according to any of the preceding claims, wherein the at least one container (61) comprises a container for deceased fish (62), the container for deceased fish (62) is connected to a hose for deceased fish (52), and the container for deceased fish (62) is connected to an extraction opening (69; 692) arranged to be connected to a vessel (8).

6. The facility (1) according to any of claims 1 to 3, wherein the at least one container (61) comprises a feed container (64), the feed container (64) is connectedRectified sheetNIPO12 to a feed hose (54) and the feed container (64) is connected to an inlet (60; 604) arranged to be connected to a vessel (8).

7. The facility (1) according to claim 5, wherein the buoy (6) is provided with a feed system (65) arranged to supply feed to each section (4) through the feed hose (54).

8. The facility (1) according to claim 6, wherein the buoy (6) is provided with a plurality of feed containers (64), and the feeding system (65) is arranged to choose between feed from several feed containers (64) and optionally supply feed to each section (4) from the chosen feed container (64).

9. The facility (1) according to any of the preceding claims, wherein each section (4) is connected to the buoy (6) by a fish transfer hose (57), and the buoy (6) is provided with a fish transfer connection (67) that may be connected to a vessel (8) arranged to supply fish (7) from the vessel (8) to the buoy (6), or to a vessel (8) arranged to receive fish (7) from the buoy (6).

10. The facility (1) according to claim 8, wherein the buoy (6) is provided with an internal fish distribution system (68), the fish distribution system (68) is connected to a plurality of fish transfer hoses (57), and the fish distribution system (68) is arranged for at least one of:- guiding fish (7) from an optional first section (4) through a first fish transfer hose (57) to the fish distribution system (68), and from the fish distribution system (68) through an optional second fish transfer hose (57) to a second section (4); and- distributing fish (7) from the vessel (8) through the fish distribution system (68) to an optional section (4) through the fish transfer hose (57).

11. A method for farming fish (7), c h a r a c t e r i z e d i n that the method comprises:- providing a facility (1) for farming fish (7) according to any of claims 1 to 10;- transferring fish (7) to at least one of the sections (4);- transferring fish (7) from the lower portion (49) of the at least one section (4) to the buoy (6) through the fish transfer hose (57) by one of:- raising the section (4) vertically so that the section (4) essentially is above a water surface (9) and the fish (7) is crowded together in the lower portion (49) of the section (4); and- providing a crowding element to the section (4), activating the crowding elementRectified sheetNIPO13 so that it covers the cross-section of the section (4) in the upper portion (40) of the section (4), and guiding the crowding element downwards in the section (4) so that the fish (7) is crowded together in the lower portion (49) of the section (4).

12. The method for farming fish (7) according to claim 11 , wherein the fish (7) is transferred to the vessel (8) through the fish transfer connection (67).

13. The method for farming fish according to claim 11 or 12, wherein feed is transferred from a vessel (8) to the at least one feed container (64), and the feeding system (65) distribute feed to an optional section (4) through the feed hose (54).

14. The method for farming fish (7) according to any of claims 11 to 13, wherein deceased fish (7) is transferred from a section (4) to the at least one container for deceased fish (62) through the hose for deceased fish (52).

15. The method for farming fish (7) according to any of claims 11 to 14, wherein fish (7) is transferred from a section (4) to another section (4) by fish (7) being guided from an optional first section (4) through the first fish transfer hose (57) to the fish distribution system (68), and from the fish distribution system (68) through an optional second fish transfer hose (57) to the second section (4).

16. The method for farming fish (7) according to any of claims 11 to 15, wherein the fish distribution system (68) distributes fish (7) from a vessel (8) through the fish transfer connection (67) to an optional section (4) through the fish transfer hose (57).Rectified sheet

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