AU2014201866C1

AU2014201866C1 - A fish stock protection system

Info

Publication number: AU2014201866C1
Application number: AU2014201866A
Authority: AU
Inventors: Peter Bender
Original assignee: HUON AQUACULTURE GROUP Ltd
Current assignee: HUON AQUACULTURE GROUP Ltd
Priority date: 2013-08-14
Filing date: 2014-04-01
Publication date: 2020-06-04
Anticipated expiration: 2034-04-01
Also published as: AU2019226202A1; AU2014201866B2; AU2017272299A1; AU2014201866A1

Abstract

A fish stock protection system 10 including a frame structure 12 having a buoyant inner ring 14, and a buoyant outer ring 18, with the outer ring 18 provided in a generally common plane with the inner ring 14 and extending about the inner ring 14. The system 10 also includes a plurality of connectors 20 spaced about the frame structure 12, with each connector 20 provided for connecting the inner ring 14 to the outer ring 18. The system 10 further includes a rail assembly 22 connected to each respective connector 20. The rail assembly 22 supports a stock containment net 24, with the stock containment net 24 suspended in a space surrounded by the inner ring 14. The stock containment net 24 has an upwardly facing opening 28. The system 10 also includes a predator net assembly 30 including a respective predator net mount 32 connected to each connector 20. The predator net mounts 32 support a predator net 34. In use, the predator net 34 is spaced from and suspended about the stock containment net 24. <filename> 1, _ ., ,,,,. . - .,-:-:-:-,::X '- ".:.:.,... .:: .. .` , , , , . ,:: : -\: .\ , , -,, ,, . X': ,,,,, -.'. - .'.,.\ - ' ':j -` :j: :j: : j: . I .i . . \ . M\ .. , . % ..'.. i "I -.,' .\ I ".. ;,4. .",., -.*- ..\ ,\ ,,,, .\ - .\ . \. .. - X X.:-:.,:. .\:. .,.x-:.\., .' , "I ,N , ".11 lk , 1 . ... % . < N . . * . IN .. M '30 :: ' * ::i*. .*i*i*:* *:: i: -::i*]* *:: , W F "' .. .. i 1 . . .- , ... ,i::: .i .*.. K ,. . .. , . . . , N _ N F, V. wg" '.." 'I., ,, , . . \ , ,\ I . , , '.. - :-:-. - ...- n .. , .. :::, . ,.. ... , ' \ \\ u ,\ . .% k , n ,,:: .. ., 11 I " 11 "\ , , '11' , , " - I , 'I . , . . , . i .. ", 1\ .I ... , \- .: -, --" `: :X-. I . . .1. . . li . . ., i., 11 I - xp gg " ... : : : m - \ ,%\ :, ,:, '.. .k ",: *," "*.I X:: ,., , . , , . ... I " , ,-K. :.\ - \ , ".... , , , ::.:.:.:.:.I. :1 I : : I - w . . .:, x\ I. .nl , %, x".: : ,', .-':' ': "' , ::,: :::i:i: , i:i:i:i::.". :: :i:i: ,,' .*' '..' :::i.".: : i:i.-.-.-.-.-.-. r -l : , ,_, ... :- .... ,., ,, , . llm l a * , .. " , . , .. "-:*\, ::: -- ,' .:,. " .... * :.:..,.:::. - :: : ', . ., x -.. :..-l;.%\ : , . . ., . , I , . ., , , ', .l .... , ..,.\ .:, , _ k "-, . '... - , , . a , * I : .., 1111..' 1111 1111 - m \ , . . , . ..,. : :::

Description

A FISH STOCK PROTECTION SYSTEM

Introduction [0001] The present invention relates generally to the farming of fish. The invention has particular application to the farming of fish species such as salmon in open water and so will be generally described in this context. However, the invention is considered to have wider application and so could be used in the farming of other fish and sea life species.

Background of Invention [0002] Existing stock containment systems (or ‘pens’) are designed to contain the fish stock(s) being farmed in open water, until such time as the fish are ready to be harvested. Such systems generally include a buoyant (or flotation) structure that supports a stock containment net. These types of systems may be movable, such that they can be periodically moved between locations in order to maintain the health and well-being of the fish - a method known as fallowing.

[0003] These types of systems have been shown to work well in terms of farming healthy fish, but have been shown to be largely ineffective in terms of denying access to sea predators such as seals.

[0004] If a seal gains access into a net then they can strike at thousands of fish and, in turn, seriously erode the financial viability of the farming operation. Some estimates place the loss of fish to seals at 10 to 15% or more. With commercial fish farming enterprises often producing tens of thousands of tonnes of fish a year, a percentage loss of fish of this order is very significant indeed.

[0005] Some seals weigh in excess of 400kg, and so can also pose a threat to staff working on and in the vicinity of such systems. Seals can also cause significant damage to the nets and supporting structures.

[0006] The current design of stock containment systems means that seals are potentially able to access the stock containment nets either above or below the water surface, either by creating a hole in the net and entering the net through the hole, or by climbing over the top edge of the net. Seals regularly climb over the top edge of

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2014201866 01 Apr 2014 existing nets, even when the top edge of the net is 1m or more above the water surface. Seals are assisted in this regard by the current design of the buoyant frame structure, onto which the seals can climb with relative ease. Once on top of the frame structure, it is a relatively simple task for a seal to climb over the top edge of the net to access the fish.

[0007] Addressing the problem caused by seals can be complex, since seals are a protected species in Australia and in many other parts of the world, and further because seal numbers are increasing.

[0008] One current strategy for deterring seals is to provide an additional layer of netting above the water line about the top of the stock containment net. However, this has been shown to be largely ineffective, as seals either scale over or under the additional netting layer, or simply break the netting to access the fish.

[0009] The applicant is regularly required to trap seals that have accessed their existing stock containment nets and relocate them. This, however, often doesn’t solve the problem, as the seals can return in as little as 3 days, even when relocated 500km away.

[0010] Another problem experienced with existing fish stock containment systems is that of birds feeding on the fish feed. Birds often also target the fish, particularly smaller fish. For example, gulls tend to target the fish feed pellets; while cormorants mainly target smaller fish (generally less than 500 grams). Bird species such as gulls and cormorants are protected species in Australia and in other parts of the world and, at least partly as a result, their numbers are increasing.

[0011] The presence of birds can also put the fish off feeding, which is undesirable in a fish farming enterprise. It has been estimated by the applicant that they currently lose anywhere from 1 to 2% of their fish farm gate value to birds. Bird net arrangements have been used previously, although these have not been entirely successful at keeping birds away from the fish and fish feed. Further, birds often become entangled in existing bird nets, which is undesirable from an animal welfare point of view.

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2014201866 20 Jan 2020 [0012] It would therefore be desirable to at least partially address one or more of the shortcomings mentioned above of existing fish stock containment systems.

Summary of Invention [0013] Reference in the specification to orientation terminology, such as “upwardly”, “downwardly”, “vertical” and the like is used for illustrative purposes with the invention provided in its intended in-use orientation. Such terminology is not in any way intended to limit the scope of protection sought in the accompanying claims.

[0014] According to a broad aspect of the present invention, there is provided a fish stock protection system. The system includes a frame structure including a buoyant inner ring, and a buoyant outer ring, with the outer ring provided in a generally common plane with the inner ring and extending about the inner ring. The system also includes a plurality of connectors spaced about the frame structure, with each connector provided for connecting the inner ring to the outer ring. The system further includes a rail assembly connected to each respective connector. The rail assembly supports a stock containment net, with the stock containment net suspended in a space surrounded by the inner ring. The stock containment net has an upwardly facing opening. The system also includes a predator net assembly including a respective predator net mount connected to each connector. The predator net mounts support a predator net. In use, the predator net is spaced from and suspended about the stock containment net. In use, an outer edge region of the predator net is suspended above the water line, with the remainder of the predator net suspended below the water line. A lower edge region of the predator net is surrounded by and connected to a shape retaining and weighted ring extending about the lower edge region of the predator net, so as to retain the lower edge region of the predator net in a generally circular shape [0015] It is to be appreciated that the present invention may be utilized to protect a variety of sea life including, but not limited to fish such as salmon.

[0016] Reference has been made to the inner and outer rings being provided in a generally common plane. It is envisaged that, in use, this would be a generally horizontal plane.

2014201866 20 Jan 2020 [0017] The applicant has discovered that the provision of a predator net surrounding and spaced from the stock containment net provides a greatly improved arrangement that prevents seals from entering or otherwise accessing the stock containment net to devour the fish stock therein contained.

[0018] In a preferred form, the system further includes a bird net assembly. The bird net assembly is supported by each respective connector above the stock containment net, and is provided so as to prevent bird access to the stock containment net through the upwardly facing opening of the stock containment net.

[0019] The provision of a bird net assembly is desirable because it prevents the loss of feed stock added to the stock containment net, which may otherwise be consumed by birds. It also prevents birds feeding on the fish, particularly smaller fish, contained in the stock containment net.

[0020] It is to be appreciated that, in use, the fish stock protection system would float in water, with the rings providing the desired amount of buoyancy. In a particularly preferred form, an outer edge region of the stock containment net would be suspended above the water line, and the remainder of the stock containment net would be suspended below the water line. In one form, the outer edge region of the stock containment net extends about the periphery of the stock containment net and, in use, extends out of the water to a height of approximately 1m.

[0021] The outer edge region of the predator net most preferably extends about the periphery of the predator net and, in use, extends out of the water to a height of approximately 3m. Extending this distance out of the water has been shown to be a significant deterrent to seals when attempting to access fish in the stock containment net. Seals are unable to jump or climb over the predator net of the present invention, and so are unable to access the fish in the stock containment net. Further, the seals are unable to breach the predator net, given its unique design - details of which will be provided hereinafter.

2014201866 01 Apr 2014 [0023] A lower edge region of the stock containment net is also preferably connected to one of the lower edge region of the predator net and the shape retaining ring, so as to retain the lower edge region of the stock containment net in a generally circular shape. In this way both the predator and stock containment nets are retained in their desired, in use, shapes.

[0024] So far, the invention has been described as having an inner ring and an outer ring. However, it is envisaged that the system would preferably also include an intermediate buoyant ring. Preferably, the intermediate ring is provided in the generally common plane with the inner and outer rings, and with each of the connectors connecting the intermediate ring to the inner and outer rings.

[0025] In a preferred form, each connector includes a connector body. The connector body may include an inner ring receiving aperture for receiving about a respective inner ring wall portion; as well as an outer ring receiving aperture for receiving about a respective outer ring wall portion. If the system includes an intermediate ring, then each connector may also include an intermediate ring receiving aperture for receiving about a respective intermediate ring wall portion. It is envisaged that the inner, intermediate and outer ring receiving apertures are provided in a generally common plane, given that the rings are arranged in a generally common plane.

[0026] The rail assembly may include a respective upstanding rail mounting post extending from each connector body, with a generally ring-shaped rail connected to each of the rail mounting posts. In use, the rail is preferably mounted generally above the inner ring. The invention also contemplates mounting the rail at other possible locations, other than above the inner ring. The rail can be utilised as a hand rail by staff.

[0027] The stock containment net may be supported by the rail mounting posts. In this regard, the stock containment net may be connected to each of the posts by a hook.

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2014201866 01 Apr 2014 [0028] The upstanding rail mounting post of each connector may extend generally perpendicularly to the common plane, if desired.

[0029] The predator net mount of each connector may be provided on a predator net mount arm connected to and extending upwardly from the connector body.

[0030] It is envisaged that the predator net mount arm of each connector would extend upwardly from the connector body in a non-vertical direction. As such, the arm may extend extending upwardly and outwardly from the connector body at an angle of between approximately 4°and 15°to vertical, when the connector body is in its in-use orientation. This arrangement is desired, because it allows the base of the arm to be mounted slightly inwardly from the outer edge of the connector, thereby lessening the likelihood of the arm sustaining impact damage from boats pulling alongside the protection system. In a particularly preferred form, the predator net mount arm of each connector extends upwardly and outwardly from the connector body at an angle of approximately 8°to vertical, when the connector body is in its in-use orientation.

[0031] Each connector may include a bird net mount provided on a respective bird net mount arm connected to and extending upwardly from the connector body.

[0032] It is envisaged that each of the connectors is manufactured at least substantially from high density polyethylene (HDPE). Such a material is desired, because it is relatively robust. This allows the connectors to be twisted and otherwise deformed by without damage. Further, HDPE does not corrode, and therefore is a more preferred material than the use of connectors manufactured from steel.

[0033] The invention has, so far, been generally described in the context of a fish stock protection system. However, the invention is also directed to a connector for use in a fish stock protection system. Thus, according to another broad aspect of the present invention, there is provided a connector for use in a fish protection system. The connector includes a connector body, with the connector body including an inner ring receiving aperture for receiving about a respective inner ring wall portion; and an outer ring receiving aperture for receiving about a respective outer ring wall portion.

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2014201866 01 Apr 2014

The inner and outer ring receiving apertures are provided in a generally common plane.

[0034] In a preferred form, the connector body includes an intermediate ring receiving aperture for receiving about a respective intermediate ring wall portion. In such an arrangement, each of the inner, intermediate and outer ring receiving apertures is provided in the generally common plane.

[0035] In one form, the connector includes an upstanding rail mounting post for mounting a rail thereto. The upstanding rail mounting post may extend generally perpendicularly to the generally common plane.

[0036] The connector preferably includes a predator net mount provided on a predator net mount arm, with the arm connected to and extending upwardly from the connector body when the connector body is provided in its in-use orientation. The predator net mount arm preferably extends from the connector body in a non-vertical direction, as previously discussed.

[0037] In one form, the connector includes a bird net mount provided on a respective bird net mount arm connected to and extending upwardly from the connector body when the body is provided in its in-use orientation.

Brief Description of Drawings [0038] It will be convenient to hereinafter describe preferred embodiments of the invention with reference to the accompanying figures. The particularity of the figures is to be understood as not limiting the preceding broad description of the invention.

[0039] Figure 1 is a side view of one embodiment of a fish stock protection system according to the present invention.

[0040] Figure 2 is a side view of the system shown in Figure 1, but with the predator net assembly removed.

[0041] Figure 3 is a side view of the system of Figure 1, but with the predator net assembly and the bird net assembly both removed.

[0042] Figure 4 is a side view of one embodiment of a connector used in the system of Figure 1.

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2014201866 01 Apr 2014 [0043] Figure 5 is a side view of a predator net mount arm for attachment to the connector shown in Figure 4.

[0044] Figure 6 is a perspective view of a partially constructed portion of a fish stock protection system prior to installation in a body of water, according to another embodiment of the present invention.

[0045] Figure 7 is another perspective view of the partially constructed portion of the system illustrated in Figure 6.

Detailed Description [0046] Referring to Figures 1 to 5, there is illustrated a fish stock protection system 10. The system 10 has been specifically designed for protecting the Applicant’s farmed salmon stock, although the system 10 could equally be used or adapted for use with other fish and sea life varieties.

[0047] The system includes a frame structure 12 having three buoyant rings, including an inner ring 14, an intermediate ring 16, and an outer ring 18. The construction of the rings 14, 16, 18 is such that they provide sufficient buoyancy to retain the system 10 in it’s in use position extending both above and below the water surface. It can be seen that the rings 14, 16, 18 are provided in a generally common horizontal plane. The overall circumference of the inner ring 14 is marginally smaller than that of the intermediate ring 16 which, in turn, is marginally smaller than that of the outer ring 18. As such, the rings 14, 16, 18 can be concentrically arranged in relatively close proximity. The rings 14, 16, 18 provide a relatively rigid frame structure 12.

[0048] The system 10 also includes a plurality of connectors 20 (or brackets) spaced about the frame structure 12. Only some of the connectors 20 have been labelled in Figures 1 to 3. A connector is shown in Figure 4.The specific design of the connectors 20 is considered unique. Each connector 20 is provided for connecting the inner, intermediate and outer rings 14, 16, 18 together. The connectors 20 are manufactured from HDPE in an injection moulding process. HDPE has been found to be a robust material able to withstand the harsh operating environment in which the connectors 20 are used. The use of HDPE also avoids the problem of corrosion, which would be an issue if the connectors were manufactured from steel.

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2014201866 01 Apr 2014 [0049] The system 10 further includes a rail assembly 22 connected to each respective connector 20. The rail assembly 22 supports a stock containment net 24 by way of hooks or other appropriate connector arrangement, with the stock containment net 24 suspended in a space 26 surrounded by the inner ring 14. The stock containment net 24 has an upwardly facing opening 28. The stock containment net 24 is provided for containing farmed salmon, or other desired fish or sea life variety (or varieties).

[0050] A predator net assembly 30 is provided. The predator net assembly 30 includes a respective predator net mount 32 connected to each connector 20. The predator net mounts 32 support a predator net 34. In use, the predator net 34 is spaced from and suspended about the stock containment net 24.The primary function of the predator net 34 is to deter seals and other sea predators from attempting to access the stock containment net 24 and gain access to the fish therein provided. The provision of a predator net 34 is therefore considered a great advancement on existing fish pen arrangements that do not include a predator net.

[0051] The stock containment and predator nets 24, 34 are both preferably manufactured from an ultra- high strength -polyethylene (UHSPE).

[0052] The system 10 further includes a bird net assembly 40. The bird net assembly 40 is supported by each respective connector 20 above the stock containment net 24, and is provided for preventing bird access to the stock containment net 24 through the upwardly facing opening 28 of the stock containment net 24. The bird net assembly 40 includes a bird net 42. The bird net 42 substantially covers the entire opening 28 of the stock containment net 24. The bird net 42 is also preferably manufactured from an ultra-high strength polyethylene. As stated previously, the provision of a bird net assembly 40 is desirable, because it prevents or at least limits the loss of feed stock added to the stock containment net 24, which would otherwise be consumed by birds. This, in turn, increases the profitability of the fish farming enterprise, and better allows the fish stock to be fed at the desired rate. It also prevents birds taking the fish, particularly the smaller fish.

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2014201866 01 Apr 2014 [0053] Although not entirely clear from the drawings, each of the rings 14, 16, 18 would be sufficiently buoyant to float on or proximate to the water surface. In this way, the outer peripheral edge region 46 of the stock containment net 24 extends out of the water to a height of approximately 1m, while the remainder of the stock containment net 24 is suspended below the water line.

[0054] In use, the outer peripheral edge region 50 of the predator net 34 is suspended above the water line to a height in the order of 3m; with the remainder of the predator net suspended below the water line. A height of around 3m has been shown to significantly deter seals attempting to access fish in the stock containment net 24. This is because seals are unable to jump or climb over the predator net 34 (nor penetrate the predator net fabric), and so are unable to access the fish in the stock containment net 24.

[0055] It can be seen in Figure 1 that a lower edge region 52 of the predator net is surrounded by and connected to a shape retaining and weighted ring 54 (also known as a ‘sinker ring’). The ring 54 is at least relatively rigid, so as to maintain the lower edge region 52 in a generally circular shape and to maintain it in a spaced relationship with the stock containment net 24. In this regard, it can be seen that a lower edge region 56 of the stock containment net 24 is also connected (by way of connecting ties 58) to one of the lower edge region 52 of the predator net 34 and the shape retaining ring 54 to retain the lower edge region of the stock containment net 24 in a generally circular shape. In this way both the predator and stock containment nets 34, 24 are retained in their desired, in use, shapes. Moreover they remain separated underwater, thereby distancing seals and other predators from fish contained within the stock containment net 24.

[0056] Figure 4 illustrates a connector 20. It is envisaged that each of the connectors 20 would be identical. It can be seen that the connector 20 includes a connector body 60. The connector body 60 includes an inner ring receiving aperture 62 for receiving about a wall portion of the inner ring 14. The connector body 60 also includes an intermediate ring receiving aperture 64 for receiving about a wall portion of the intermediate ring 16; and an outer ring receiving aperture 66 for receiving about

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2014201866 01 Apr 2014 a wall portion of the outer ring 18. Each of the apertures 62, 64, 66 is shaped and sized to be received snugly about the respective ring 14, 16, 18.

[0057] The rail assembly 22 provided on the connector 20 includes a respective upstanding rail mounting post 70. The post 70 is manufactured from HDPE and is fitted and secured to the connector body 60 during the connector assembly process. A generally ring-shaped rail 72 (shown in Figures 1 to 3) extends through a bore 73 (see Figure 4) provided on the top of each rail mounting post 70 to retain the rail 72 in position. It can also be seen from Figure 4 that the rail 72 is mounted generally above the inner ring 14, and at a height of approximately 1 m above the surface of the water. The net 24 is connected to the posts 70 by way of hooks or other suitable connectors (not clearly shown).

[0058] A predator net mount arm 74, containing net mounts having lugs 76a and cleats 76b, is illustrated in Figure 5. The arm 74 is manufactured from HDPE. The illustrated arm 74 is designed for connection to the connector body 60 during the connector assembly process, with the arm 74 received in a bore 78 (see Figure 4) extending through the connector body 60. The arm 74 is designed to extend upwardly and outwardly from the connector body 60 when connected thereto, at an angle of approximately 8°to vertical when the connector body 60 is in its in-use orientation. Again, this arrangement is desired, because it allows the base of the arm 74 to be mounted slightly inwardly from the outer edge of the connector 20, thereby lessening the likelihood of the arm 74 sustaining impact damage from boats pulling alongside the protection system.

[0059] Each connector 20 has the capacity to fit a bird net mount arm 80 containing a bird net mount 82. The arm 80 may be of any suitable length, and in the illustrated embodiment is in the order of 2650mm long. The arm 80 is manufactured from HDPE and is connected to the connector body 60 during the connector assembly process. As can be seen from Figure 4, the arm 80 extends upwardly from the connector body 60. The arm 80 extends from the connector 20 at a non-vertical angle. The mount 82 is in the form of an opening 84 provided in the upper end of arm 80. The opening 84 is provided for receiving a lower 1.3 m (approx.) portion of a flexible pole 86 (shown in Figures 1 and 2), with the remaining portion of the flexible

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2014201866 01 Apr 2014 pole 86 extending upwardly from the opening 84. The pole 86 is connected to and supports the bird net 42.

[0060] It can be seen in Figure 1 that a specialized staff access area 90 is provided in the upper edge region of the predator net 34. This allows staff to access the space above the rings 14, 16, 18 and between the nets 24, 34, as required.

[0061] Any dimensions shown on the drawings are to be interpreted in a nonlimiting manner, and are shown merely to illustrate one possible embodiment of the invention.

[0062] Decking sections 192 are shown in the embodiment of Figures 6 and 7, in respect of a partially constructed fish stock protection system 110. The decking sections 192 provide a relatively flat walking surface for staff to move about the system 110 as and when required. The decking sections 192 have a lattice structure, thereby preventing the pooling of water thereon, which may otherwise prove hazardous to walk on. It can be seen from Figures 6 and 7 that the provision of three rings 114, 116, 118 is desirable because it provides a relatively wide space for accommodating staff and equipment.

[0063] The fish stock protection system 10/110 in accordance with the present invention not only suitably contains the fish stock(s) being farmed, but has been found to be very effective in denying access to predators such as seals. This is a marked benefit, in that fish stock loss to predators does not compromise the financial viability of the farming operation in the way that occurs with existing fish stock containment systems.

[0064] Denying access to seals and the like also improves the safety of staff, given that the threat posed to staff by having to trap and relocate seals from the containment system is removed.

[0065] The invention also greatly reduces the likelihood of damage to the nets and supporting structures by seals that would otherwise necessitate repair or replacement.

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2014201866 01 Apr 2014 [0066] The provision of a bird net substantially covering the opening of the stock containment net also prevents access by birds to the fish and fish feed, which provides another benefit of the invention. The relative absence of birds when using the present invention also potentially addresses the issue of fish being put off feeding which can occur with birds being present.

[0067] The specific bird net design of the present invention has also been found to potentially reduce the likelihood of birds becoming entangled therein.

[0068] Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the construction and arrangement of the parts previously described without departing from the spirit or ambit of this invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A fish stock protection system, including:

frame structure including a buoyant inner ring, and a buoyant outer ring, with the outer ring provided in a generally common plane with the inner ring and extending about the inner ring;

a plurality of connectors spaced about the frame structure, with each connector provided for connecting the inner ring to the outer ring a rail assembly connected to each respective connector, the rail assembly supporting a stock containment net, with the stock containment net suspended in a space surrounded by the inner ring, the stock containment net having an upwardly facing opening; and a predator net assembly including a respective predator net mount connected to each connector, with the predator net mounts supporting a predator net, and with the predator net, in use, spaced from and suspended about the stock containment net; and wherein, in use, an outer edge region of the predator net is suspended above the water line and the remainder of the predator net is below the water line;

wherein a lower edge region of the predator net is surrounded by and connected to a shape retaining and weighted ring extending about the lower edge region of the predator net to retain the lower edge region of the predator net in a generally circular shape.
2. A fish stock protection system according to claim 1, including a bird net assembly, with the bird net assembly supported by each respective connector above the stock containment net for preventing bird access to the stock containment net through the upwardly facing opening of the stock containment net.
3. A fish stock protection system according to claim 1 or 2, wherein, in use, the fish stock protection system floats in water, with an outer edge region of the stock containment net suspended above the water line and the remainder of the stock containment net below the water line.
4. A fish stock protection system according to claim 3, wherein the outer edge region of the stock containment net extends about the periphery of the stock containment net and, in use, extends approximately 1m above the water line.

2014201866 20 Jan 2020
5. A fish stock protection system according to any one of the preceding claims, wherein the outer edge region of the predator net extends about the periphery of the predator net and, in use, extends approximately 3m above the water line.
6. A fish stock protection system according to any one of the preceding claims, wherein a lower edge region of the stock containment net is connected to one of the lower edge region of the predator net and the shape retaining ring to retain the lower edge region of the stock containment net in a generally circular shape.
7. A fish stock protection system according to any one of the preceding claims, including an intermediate buoyant ring, with the intermediate ring provided in the generally common plane with the inner and outer rings, and with each connector connecting the intermediate ring to the inner and outer rings.
8. A fish stock protection system according to claim 7, wherein, in use, the generally common plane is a generally horizontal plane.
9. A fish protection system according to claim 7 or 8, wherein each connector includes a connector body, the connector body including an inner ring receiving aperture for receiving about a respective inner ring wall portion;

an intermediate ring receiving aperture for receiving about a respective intermediate ring wall portion; and an outer ring receiving aperture for receiving about a respective outer ring wall portion;

wherein the inner, intermediate and outer ring receiving apertures are provided in a generally common plane.
10. A fish protection system according to claim 9, the rail assembly including a respective upstanding rail mounting post extending from each connector body, with a generally ring-shaped rail connected to each of the rail mounting posts, such that, in use, the rail is mounted generally above the inner ring.
11. A fish protection system according to claim 10, the upstanding rail mounting post of each connector extending generally perpendicularly to the common plane.

2014201866 20 Jan 2020
12. A fish protection system according to any one of the preceding claims, with the predator net mount of each connector provided on a predator net mount arm connected to and extending upwardly from the connector body.
13. A fish protection system according to claim 12, wherein the predator net mount arm of each connector extends upwardly from the connector body at an angle of between approximately 4° and approximately 15° to vertical, when the connector body is in its in-use orientation.
14. A fish protection system according to claim 13, wherein the predator net mount arm of each connector extends upwardly from the connector body at an angle of approximately 8° to vertical, when the connector body is in its in-use orientation.
15. A fish protection system according to claim 2, or any one of claims 3 to 14 when directly or indirectly dependent from claim 2, with each connector including a bird net mount provided on a respective bird net mount arm connected to and extending upwardly from the connector body.
16. A fish protection system according to any one of the preceding claims, wherein each of the connectors is manufactured at least substantially from high density polyethylene (HDPE).
17. A fish protection system according to any one of the preceding claims, wherein each connector includes a connector body, the connector body including an inner ring receiving aperture for receiving about a respective inner ring wall portion; and an outer ring receiving aperture for receiving about a respective outer ring wall portion, and with the inner and outer ring receiving apertures provided in a generally common plane.