WO2014072788A1

WO2014072788A1 - System and method for fish farming

Info

Publication number: WO2014072788A1
Application number: PCT/IB2013/002447
Authority: WO
Inventors: Jonathan David HANDRUS
Original assignee: Maya Fish Pte. Ltd.
Priority date: 2012-11-06
Filing date: 2013-11-05
Publication date: 2014-05-15

Abstract

A system and method for open ocean fish farming is disclosed. A set of fish cages are held by ropes to several transverse members allowing for the cages and members to move relative to one another. The transverse members are themselves held by a set of ropes to a plurality of anchors such that the entire system is non-rigid and has a degree of compliance adapted to easily absorb most incident wave and current energy. Multiple anchors eliminate the anchor as a single point of failure, and multiple connections between main body and anchor spread stresses and tensions evenly throughout the structure.

Description

SYSTEM AND METHOD FOR FISH FARMING

BACKGROUND

Technical Field

[0001] The present invention relates to a method and structure adapted for fish farming on the open sea.

Description of Related Art

[0002] Various methods and systems have been developed for the production of fish in the open sea. Some of these comprise structures that support the fish cages and nets to fish cages. Recent efforts include Patent Application U.S. U.S. 2006/0130728 from Noam Zeichner and Omri Bel-Eliyahu. Here a fish cage system is used for offshore aquaculture using a single buoyant frame designed to absorb wave energy by means of a flexible construction holding the fish nets. Furthermore the system is submersible by means of members which may be filled with water or air to lower or raise the cages respectively.

[0003] The buoyant frame is a hollow tubular body. The upper corners of the frame are connected to two horizontal arms perpendicular to the frame and which extend along the length of the device. These arm are hollow and sealed at their free ends, so that they serve as tanks to store water or air to lower or raise the entire device, respectively. The buoyant frame is anchored to the sea bottom by ropes or cables. Fastened to the rope connecting the anchor and frame, is a buoy that adjusts the tension of the rope when the structure is submerged. Between the horizontal arms,a series of connecting arms are provided to hold the fish cages. These are cylindrical bodies that are joined at their lower edges to ballast chains.

[0004] Patent application U.S. 2010/0050952 from Harold M. Stillman and Richard Luco Salman describes an aquaculture cage formed by a buoyant structure shaped like a parallelepiped and configured to float on the water surface. To solve the compounded problems of corrosion of metallic cage material and infestation of plastic or other polymer cage material with parasitic and other inimical elements tending to infect the fish population, the upper portion of aquaculture net is made of a material which is relatively light, such as a metal corrodible by saltwater. The upper section of the aquaculture net is placed a distance below the water surface. Another section of the aquaculture net encloses the interior of the cage from the upper network. The bottom of the aquaculture net is likewise closed to avoid escape of marine life. The top of the grid is formed by substantially non-corrosive materials by saltwater.

[0005] US Patent 7,992,522 to Jeff Harrison et. al. provides for fish farming in the open sea that includes a series of sequentially aligned floating containers. These have coupling means adapted to flexibly connect the containers and keep them spaced with respect to each other. Buffering means attached to at least one of the containers are provided to reduce the current and waves and deflect any debris floating away from tank containers. The device also has a tank for keeping food, and means for mixing and distributing food paste to each of the plurality of containers. The tanks have means for attaching to secure the pad means to the tank, a dispenser for radially distributing the fish food in the container, an anchor and anchor means for attaching the apparatus to the ground water, wherein the anchoring means allow a radial movement of the tank or around the anchor position and a crane mounted on the fish feed tank.

[0006] US Patent application 2006/0130728A1 similarly provides a framework which forms the structure and utilizing cylindrical cages. The device uses ballast around the lower perimeter of the cage to maintain the shape of the cages, involving a greater weight and increased investment in comparison to alternative systems. For stability the frameworks allow interior cylindrical cages with two additional tangential attachment points for fastening to the structure providing greater stability.

[0007] However it remains a long felt need to provide a long-lasting fish cage system capable of distributing stress from incident wave energy across a large number of system elements.

BRIEF SUMMARY

[0008] An aspect of the present invention provides (An open ocean fish farming structure comprising: a plurality of anchors; a plurality of main ropes attached to each of said anchors; a plurality of secondary ropes attached to each of said main ropes; a set of frames held by said secondary ropes and adapted to space said secondary ropes in a predetermined pattern; a set of transverse members extending between said frames; a plurality of fish cages held by said secondary ropes and said transverse members; a plurality of ballast members adapted to hold said cages in a predetermined disposition; a set of tension ropes holding the ends of said transverse members;

[0009] wherein a set of fish cages is supported by multiple anchors by means of flexible members having compliance such that stress from incoming waves and current does not develop upon said fish farming structure. The device of claim 1 wherein said ballast members are chains.

[0010] It is further within provision of the invention wherein said cages comprise mesh walls and are attached to said secondary ropes and said transverse members by means of ropes having a degree of slack sufficient to allow a degree of play to said cages in all directions.

[0011] It is further within provision of the invention wherein said degree of play is at least one half of the average wave wavelength of waves incoming to said fish farming structure.

[0012] It is further within provision of the invention wherein said frames and transverse members may be reversibly filled with fluid.

[0013] It is further within provision of the invention to be anchored only at one end, whereby said fish farming structure may rotate about said anchor to the direction of prevailing current. [0014] It is further within provision of the invention wherein said device is adapted to spread stress upon said structure to a large proportion of said structure members.

[0015] It is further within provision of the invention wherein said frames and transverse members comprise hollow tubing comprising of polymeric material.

[0016] It is further within provision of the invention adapted to spread stress upon said device between said secondary ropes.

[0017] It is further within provision of the invention wherein said transverse members are held by ropes only and thereby are not held by any member rigid in both compression and in tension.

[0018] These, additional, and/or other aspects and/or advantages of the present invention are: set forth in the detailed description which follows; possibly inferable from the detailed description; and/or Iearnable by practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to understand the invention and to see how it may be implemented in practice, a plurality of embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figure 1 is an isometric view of the fish farm

Figure 2 is closeup of the retainer

Figure 3 is another detail view of the retainer

Figure 4 is a side view of the fish farm

Figure 5 is a closeup side view of the retainer showing he attachment of the vertical frame with horizontal arms. Figure 6 is a representation of the cages supported on the main frame showing weights.

Figure 7 is a close-up side view of one of the cages Figure 8 depicts the system in its entirety in isometric view Figure 9 further depicts the system in its entirety in isometric view Figure 10 depicts the system in its entirety in top view Figure 11 is a close-up side view of the retaining elements Figure 12 is a close-up top view of the cage frame Figure 13 is a close-up top view of the flipper delta swivel.

DETAILED DESCRIPTION

[0020] The following description is provided, alongside all chapters of the present invention, so as to enable any person skilled in the art to make use of said invention and sets forth the best modes contemplated by the inventor of carrying out this invention. Various modifications, however, will remain apparent to those skilled in the art, since the generic principles of the present invention have been defined specifically to provide a means and method for providing a system and method for aquaculture nets.

[0021] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. However, those skilled in the art will understand that such embodiments may be practiced without these specific details. Just as each feature recalls the entirety, so may it yield the remainder. And ultimately when the features manifest, so an entirely new feature be recalled. To justly and entirely describe renditions of each embodiment may not yield full reportage of underlying concepts. Thus we must generally admit that not all embodiments are necessarily described herein, but that the concepts underlying the invention are themselves disclosed.

[0022] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention.

[0023] The term 'plurality' refers hereinafter to any positive integer (e.g, 1, 5, or 10).

[0024] The terms 'rope' and 'chain' refer hereinafter to any device allowing for tension to be transmitted while being largely unable to transmit compressive forces, such as a cable, braided rope, linked chain, or the like.

[0025] The structure farm is roughly rectangular device anchored to the seabed at both ends. It is preferably aligned with the dominant ocean currents such that a minimum of energy due to current is imparted to the system. The structure incorporates a system that allows floating or sinking of the structure by means of flooding hollow chamber with air or water respectively. Additionally, the invention in certain embodiments has a free end that allows a change of orientation by means of ocean currents and waves, by this means achieving greater stability over long time periods.

[0026] The technology was developed to solve certain problems encountered in previous technologies attempting to fulfill the function of the frame. Specifically, use of two longitudinal pipes only can prove problematic even if these members are somewhat flexible, since stress from incident wave and flow energy is not distributed evenly over the entire structure, leading to points of high stress concentration and device failure. Furthermore use of a single anchor has been shown to be problematic, such systems failing catastrophically in case of line breaks or anchor release.

[0027] The current device is designed to facilitate the raising and lowering of the system in storms by use of a combination of air cells and water cells located in the metal frame, enabling it to rise or sink by pumping in air, or letting air be released to be replaced by sea water. [0028] The improved technology allows the system to work in real sea conditions. In previous technologies using metallic frames, the frame was generally too heavy and had to be buoyed with air in, leading to balance problems. In addition, such frames are generally attached to the transverse members making up the side borders of the system, and the connections between the frame and transverse members is a point of failure. Certain prior art inventions allowed for the air for raising and lowering the system to flow through from the frame to the transverse members. This in practice leads to balance problems and the lowering and raising of the system is generally a very difficult task.

[0029] Some prior art systems rely on a series of chains on the bottom of the system as a means to prevent the system from sinking all the way to the bottom and collapsing the nets. This technology s known to have failed numerous times with major damage to the fish. This frame was designed to facilitate the raising and lowering of the system in storms by a combination of air cells and water cells located in the metal frame, enabling it to rise or sink by pumping in air, or letting air be released.

[0030] The new technology improves upon this system by making use of floating buoys or hollow pipes to keep the system suspended and off the bottom when in the submerged position.

[0031] With the new improved design and concept of the current invention the frame is free floating and largely independent from the transverse members. No air is required in the new frame, which instead is always full of water. The method of lowering and raising the system is very simple and only done by use of certain long tube members. The main task of the frame is to keep a set of supporting grid ropes space apart which maintains the cages volume. This can be seen with reference to Fig. 1. Here the main cables 101 attach to the anchor (not shown). These mani cables further split into a set of secondary grid ropes 102 which extend the length of the system; these ropes keep the fish cages 104 in place while allowing them to move relative to the transverse members 107. The secondary grid ropes hold the retaining member 103 in place, which in turn allows for fixed spacing of the grid ropes with respect to one another. The cages 104 comprise mesh for holding various fish or other sea creatures, as well as ballast elements 106 which may take the form of chains. These ballast elements keep the cage mesh spread out evenly while allowing for movement due to waves and current. By means of the non-rigid support provided by the grid ropes 102, the entire structure is held in place while allowing for movement on the scale of individual waves, thereby allowing for a long device lifetime even in regions of large incoming waves and current changes. In fact if the device is anchored only on one side, then the rest of the device will swing around the anchor point to be parallel to the current, allowing for the device to adapt to changing currents continuously and putting a minimum of stress thereupon.

[0032] The new double point mooring has been extensively field tested and eliminates all the weaknesses of single point mooring.

[0033] The system comprises elongated tubular structures 108 (Figure 1). One or both ends are secured to the seabed by means of anchors (not shown). The rope leading from the anchor divides into two or more sets of cords 102 of smaller diameter for holding upright rectangular frames 103 which are located at each end of the structure. The long sides of the device are largely rectangular. The grid of ropes 102 is spread by the rectangular frames 103 to be evenly spaced. They support the fish cages 104 and the tubular frame members 108.

[0034] Each frame 103 is a rectangular structure. See Fig. 11 for a closeup view. The structure is formed in some embodiments by a hollow tube of plastic material and is reinforced by vertical tubular sections 1101 which may be attached for instance by means of common "T" connecting accessories. The members 1101 divide the frame several sections.

[0035] A unique feature of the device is shown in close up in Fig. 2. The ends of the transverse members 107 are attached to the rectangular frames 103 by means of several tension ropes 201. The transverse members have ends that are bent downwards by means of the ropes 201 and hence are anchored to the frames 103 in a compliant and flexible manner. Each transverse member 107 is attached to the lower side end of the frame (103) using at least three ropes (201) with ropes () of different lengths, forcing the transverse members (107) to acquire a curvature. Each rope (201) that holds the transverse member is secured in position by the rectangular retaining frame (103) that prevents the ropes from sliding along the underside of the frame (103); both retaining members (107) may be formed for instance by hollow tubes of flexible material. These will generally be largely parallel to one another, are closed at their free ends and have a valve (not shown) allowing air filling or flooding of the tubes. At the opposite end of the structure is the second vertical frame, fastened to the transverse members 107 in the same manner described above.

[0036] The elongated tubular structure formed by the frames (103) and arms (107) is hollow inside and sealed at all joints, so that air can be filled into the structure to add buoyancy; these same members may be flooded to submerge the structure as necessary. Between the two arms 107 a series of horizontal interior frameworks having a roughly quadrangular geometry are clamped to the grid of ropes 102 and aligned for instance by means of smaller-diameter tubular structures which may also be hollow inside. In these inner frames are supported is ^" cages 104, which are held together by means allowing for relative flexibility and non-rigid attachment between transverse arms 107 and cages 104, such that the cages may travel at least several centimeters in all directions with respect to the arms 107 without experiencing restoring forces.

[0037] The fish cages 104 are largely prismatic structures using moorings for support. In one embodiment of the invention, the cages are arranged in arrays, each cage being positioned approximately with respect to one another and fastened together by ties or other suitable attachment means.

[0038] As mentioned the cages 104 are attached to the transverse members 107 by flexible attachments means having some degree of compliance. The cage may be attached on two or three sides in the manner to the transverse members and rope grid 102. The cages 104 have hanging ballast comprising chains 106 or weights for maintaining the form of the networks, preventing the cages from becoming deformed by action of the currents.

[0039] Once built, the structure is moved to where it will be attached to the seabed using an anchor at each end. An anchor chain part to be attached to a rope of sufficient diameter to withstand the stress caused by marine currents holds the structure, keeping the structure aligned according to the prevailing currents and absorbing part of the energy of the ocean currents and waves. [0040] In another embodiment of the invention, vertical frames are not employed, and the structure is anchored to the seabed only on one end, allowing 360 degree rotation in relation to the anchor in the event of marine currents having a significant variability. The anchor rope may be attached to two further divided ropes 101 with smaller diameters, wherein the thinner ropes are fastened to the vertical frame of the structure in its upper side and lower extending along the entire tubular structure, serving as auxiliary cages holding both the upper and lower holding unit of the whole structure and its flexibility.

[0041] The frame 104 is normally flooded with sea water to achieve greater stability. The lateral arms 107 which extend outwardly of the tubular structure remain filled with air at standard conditions. Different members may be individually flooded with water to allow immersion of the structure and to achieve various levels of buoyancy. Flooding of the lateral arms is performed when necessary to immerse the structure; this occurs for example when weather conditions warrant, such that the submerged structure is subjected to less stress. When the contingency has passed, then the side arms are filled with air displacing water in their interiors and allowing the entire structure to float to the surface or near the surface again. To perform this operation, the horizontal arms have a valve for filling with air and to allow flooding with water (the valves are not shown in the figures).

[0042] Fig. 3 shows the secondary ropes 102 and frame 103 with cages 104.

[0043] Fig. 4 shows a side view of the device with secondary ropes 102, transverse member 107, chains as ballast 106, and frame 103.

[0044] Fig. 5 shows a closeup of the end of transverse members 107 with connecting ropes 201 pulling the ends of the transverse members downwards.

[0045] Fig. 6 is a side view of the fish cages 104.

[0046] Fig. 7 is a further close up of a fish cage.

[0047] Fig. 8 shows the device in context of a set of ring buoys 801 and connecting members 802. The ring buoys are adapted to stand upright when the fish cages are submerged, as shown in Figs. 8 A, 8C; when the fish cages are raised to the surface, the ring buoys will lie flat as in Fig. 8B.

[0048] Fig. 9 shows an isometric view of the device.

[0049] Fig. 10 shows a top view of the device.

[0050] Fig. 11 shows a view of the frame 103.

[0051] Fig. 12 shows a close up top view of a cage frame used to support the fish cages.

[0052] Fig. 13 shows a close up view of a delta swivel. Storm Preparation

[0053] There are special provisions in the system for lowering and raising the cages in preparation for storms:

• the double rings, which may in some embodiments be used as birdstands, are disconnected from the nets.

• a valve at one end of the long tubes 108 (see Fig.l - on the end not pulled below the water) is opened. The other end of the long tube is always open.

• air bleeds out of the higher end of long tubes 108 and water flows in, causing the system to sink below the surface, (the long pipes are weighted all the time with adequate weight to sink the tubes when full of water. They remain floating when full of air.)

• the double rings remain floating and hold the system suspended at desired depth.

• after the storm passes air is put into the valve at the end of the tube by means of a long air supply tube.

• as water is forced out by the air, the system begins to rise.

• after the system is on the surface the valves are closed and the rings put in place on the center of each cage and the net re-connected.

[0054] An alternative method is for the long tubes 108 to be kept below the surface at both ends, and open to the water. In this a case in the center of the system an air valve will be placed in the long tube. The system is lowered at both ends together by opening the valve, and raised the same way by introducing air.

[0055] Although selected embodiments of the present invention have been shown and described, it is to be understood the present invention is not limited to the described embodiments. Instead, it is to be appreciated that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and the equivalents thereof.

Claims

1. An open ocean fish farming structure comprising:

At least one anchor;

At least one main rope 101 attached to said at least one anchor;

At least one secondary rope 102 attached to said at least one main rope 101; a set of frames 103 held by said secondary rope 102 and adapted to space said secondary rope 102 in a predetermined pattern; a set of transverse members 107 extending between said frames 103; at least one fish cage 104 held by said secondary rope 102 and said transverse members 107 ; at least one ballast member 106 adapted to hold said at least one cage in a predetermined disposition; a set of tension ropes 201 holding the ends of said transverse members 107; wherein a set of fish cages is supported by at least one anchor by means of flexible members having compliance such that stress from incoming waves and current does not develop upon said fish farming structure.

2. The device of claim 1 wherein said ballast members are chains.

3. The device of claim 1 wherein said cages comprise mesh walls and are attached to said secondary ropes 102 and said transverse members by means of ropes having a degree of slack sufficient to allow a degree of play to said cages in all directions.

4. The device of claim 3 wherein said degree of play is at least one half of the average wave wavelength of waves incoming to said fish farming structure.

5. The device of claim 1 wherein said frames 103 and transverse members 107 may be reversibly filled with fluid.

6. The device of claim 1 anchored only at one end, whereby said fish farming structure may rotate about said anchor to the direction of prevailing current.

7. The device of claim 1 adapted to spread stress upon said structure to a large proportion of said structure members.

8. The device of claim 1 wherein said frames 103 and transverse members 107 comprise hollow tubing comprising of polymeric material.

9. The device of claim 1 adapted to spread stress upon said device between said secondary ropes 102.

10. The device of claim 1 wherein said transverse members are held by ropes only and thereby are not held by any member rigid in both compression and in tension.

11. A method for open ocean fish farming comprising steps fo: providing a structure comprising: at least one anchor; at least one main rope 101 attached to said at least one anchor; at least one secondary rope 102 attached to said at least one main rope 101; a set of frames 103 held by said at least one secondary rope 102 and adapted to space said secondary rope 102 in a predetermined pattern; a set of transverse members 107 extending between said frames 103; at least one fish cage 104 held by said at least one secondary rope 102 and said transverse members 107 ; at least one ballast member 106 adapted to hold said at least one cage in a predetermined disposition; a set of tension ropes 201 holding the ends of said transverse members 107; and, filling said fish cages with fish; wherein a set of fish cages is supported by at least one anchor by means of flexible members having compliance such that stress from incoming waves and current does not develop upon said fish farming structure.

12. The method of claim 11 wherein said ballast members are chains.

13. The method of claim 11 wherein said cages comprise mesh walls and are attached to said secondary ropes 102 and said transverse members by means of ropes having a degree of slack sufficient to allow a degree of play to said cages in all directions.

14. The method of claim 13 wherein said degree of play is at least one half of the average wave wavelength of waves incoming to said fish farming structure.

15. The method of claim 11 wherein said frames 103 and transverse members 107 may be reversibly filled with fluid

16. The method of claim 11 anchored only at one end, whereby said fish farming structure may rotate about said anchor to the direction of prevailing current.

17. The method of claim 11 adapted to spread stress upon said structure to a large proportion of said structure members.

18. The method of claim 11 wherein said frames 103 and transverse members 107 comprise hollow tubing comprising of polymeric material.

19. The method of claim 11 adapted to spread stress upon said device between said secondary ropes 102.

20. The method of claim 11 wherein said transverse members are held by ropes only and thereby are not held by any member rigid in both compression and in tension.