WO 2008/104035 PCT/AU2008/000288 Title: A Fish Farm The present invention relates to a fish farm for growing and processing fish in freshwater or seawater. 5 Background of Invention Fish farms typically comprise large areas enclosed by nets supported by a floating structure. The fish are fed in these growing nets and grow until they are a size suitable io for harvesting. During their growth there are times when fish need to be taken out of the growing nets and processed. For example, fish may be subjected to a salt or formalin baths to remove diseases that can form on fish scales. Additionally, during harvesting some fish may be 15 returned to the growing nets if they do not meet size requirements. Removing fish from the growing nets involves manually hand netting the fish out and placing them in a processing area 20 such as a bath or a similar reservoir. Physically handling the fish in this manner creates high stress levels in the fish. In turn, it is common for fish stop eating for a couple of days, which reduces growth rates. Fish mortality also increases after handling. 25 Known methods for fish farming are labour intensive. The upkeep, monitoring, feeding and processing of fish typically requires about one full time employee for every 10,000kg of fish. 30 There is therefore a need for an improved fish farm that will maximise fish growth by minimising stress and generally make the process of fish farming more cost and time efficient. 35 WO 2008/104035 PCT/AU2008/000288 -2 Summary of the Invention In accordance with an embodiment of the present invention there is provided a fish farm comprising a structure of floating members to be floated on water, to define at 5 least one submerged enclosure defining a fish growing zone and at least one submerged enclosure defining a fish processing zone, the zones being selectively interconnected wherein fish can be herded from the growing zone to the processing zone by a moveable barrier. 10 The fish farm is preferably made of modular components to enable the farm to be constructed in any desired shape and configuration. is The processing zone is preferably a tank, which has an open top, that is supported by the floating members. The floating members are typically modular pontoons that may be arranged in any desired structural formation. 20 It is preferable that the growing zone is located adjacent the tank, and in a preferred embodiment multiple growing zones surround a central tank. The growing zones are defined by elongated areas enclosed by nets suspended in water between the floating members. 25 The tank is provided with closeable openings through which fish are transferred, wherein each opening communicates with one growing zone. For harvesting, the fish are herded towards a smaller space in the tank from where the 30 fish is harvested by hand or mechanically, for example using a fish pump. The moveable barrier is designed to move along the length of the growing zone and herd fish toward the respective 35 tank opening. The barrier is preferably provided with apertures to grade the fish as the fish are herded into WO 2008/104035 PCT/AU2008/000288 -3 the cage. The apertures may be varied, by changing the barrier type, in order to grade fish of different size. The tank too may be provided with a moveable barrier in 5 order to herd fish within the tank. The moveable barriers are designed to be raised and lowered into the tank and growing zones, and are supported and moveable on the upper platform of the floating members. 10 The modular pontoons may be connected end to end, side to side or end to side. The pontoons may be rigidly connected or pivotally connected by a pin arrangement. Bird netting may be provided above the growing and is processing zones and timed automatic feeding devices drop food into the growing zones. The floating members are made of rotationally moulded plastics and comprise a hollow body with water receiving 20 grooves on the underside of the body to create stability. The platform on the floating member may be roughened to provide anti-slip characteristics. Brief Description of the Drawings 25 An embodiment, incorporating all aspects of the invention, will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of a fish farm in 30 accordance with an embodiment of the present invention; Figure 2 is a perspective view of one section of the fish farm illustrated in Figure 1; 35 Figure 3 is a front elevation view of the fish farm illustrated in Figure 2; WO 2008/104035 PCT/AU2008/000288 -4 Figure 4 is an enlarged view illustrating Area 'A' in Figure 2; Figure 5(a) is a perspective view illustrating the tank of 5 the fish farm; Figure 5(b) is a plan view of a section of the tank and floating members of the fish farm; 10 Figure 5(c) is a section view taken at B-B of Figure 5(b); Figure 5(d) is an enlarged view of Area 'C' in Figure 5(c); is Figure 6(a) is a side elevation view of floating members of the fish farm joined perpendicularly; Figure 6(b) is a perspective view of Figure 6(a); 20 Figure 7(a) is a side elevation view of floating members of the fish farm joined linearly; Figure 7(b) is a perspective view of Figure 7(a); 25 Figure 8(a) is a first perspective view of the underside of a floating member; Figure 8(b) illustrates in perspective the upper side of a floating member; 30 Figure 8(c) is a perspective exploded view of a floating member; Figure 8(d) is an end view of a floating member; 35 Figure 8(e) is a side view of a floating member; WO 2008/104035 PCT/AU2008/000288 -5 Figure 8(f) is a second perspective view of the underside of a floating member; Figure 9 illustrates in perspective three floating members 5 joined laterally; and Figures 10 and 11 illustrate in perspective alternative types of barriers of the fish farm. 10 Detailed Description of Preferred Embodiment A fish farm 10 as illustrated in the drawings provides an improved environment in which fish of any variety can healthily grow with minimal stress until harvested. The farm can be used to grow other marine organisms such as is crustaceans and molluscs. Broadly speaking the fish farm 10 comprises a modular structure of floating members 12 which suspend the fish farm in freshwater or sea water. The farm 10 has at least 20 one submerged fish growing zone 20 from where fish are herded to at least one submerged processing zone 30 by a movable barrier. In the embodiment shown by the Figures there are many 25 growing zones 20 to one processing zone 30. The processing zone is located central of and adjacent to the growing zones so that fish may swim from one zone to the other. Other embodiments may include many growing zones adjacent to many processing zones. 30 As suggested, small fish, for example of about 200g in weight, are brought to the growing zone 20 to live and grow. Using cod as an example, the fish can grow to 800g to over 2kg before being harvested. 35 The growing zones 20 are defined by nets 22 submerged in water and hooked between rows of floating members 12. For WO 2008/104035 PCT/AU2008/000288 -6 the purpose of clarity nets 22 are not illustrated in Figure 1, but they are illustrated in Figures 2 to 4. The nets extend around the sides and bottom of the growing zone, which is elongated and substantially rectangular 5 parallelpiped in shape, and taper towards the processing zone. As an example, the growing zone in the preferred embodiment is 13m x 2m x 2m in volume. The top of the growing zone is open to allow for feeding 10 of the fish. Bird netting may however be placed over the top of each growing zone 20, or alternatively over the entire fish farm, to prevent fish being eaten by birds. Automatic feeders 17 are placed over the growing zone and timed to drop feed into the growing zone. 15 At times during the life of the fish and at harvesting, the fish are required to be processed. This may for example occur where the fish require cleaning in a salt bath or formalin to remove scale disease. Fish processing 20 is carried out in the processing zone 30 which in the embodiment shown is a central open tank 32. Tank 32 is also rectangular box-shaped and contains access openings 34 that are each in direct communication with one growing zone such that fish contained in that growing zone can 25 access the tank through the respective opening 34. Openings 34 are closeable by way of vertical sliding doors 35, and most of the time the doors are in a closed position while the fish are kept in the growing zones 20. 30 Doors 35 slide within door frames 36 mounted on the periphery of opening 34. When herding fish from a growing zone 20 to tank 32, a barrier in the form of a grader 25 (illustrated in Figure 35 10) is dropped into the end of the growing zone furthest from the tank 32 and moved toward the open opening 34 in the tank. Grader 25 includes a support frame 26 mounted WO 2008/104035 PCT/AU2008/000288 -7 on two pairs of wheels 27 where the wheel pairs are separated by a distance larger than the gap 14 between two rows of floating members 12. Accordingly the support frame 26 can be positioned across gap 14 and above growing 5 zone 20 by placing each pair of wheels on an upper surface 16 of opposite floating members across gap 14. Support frame 26 carries a gate 28 which can be raised and lowered within guide slots 29 in support frame 26. In a io lowered position gate 28, which is rectangular, spans across most of the width of the growing zone so to urge fish to swim in the direction that the grader moves. While the grader is not illustrated positioned within a growing zone, it can be imagined from Figure 2 that the is grader straddles and rolls on floating members 12 from one end of growing zone 20 to the other with gate 28 submerged in water. Gate 28 has sizing bars 41 for sizing fish as the grader 20 moves along the growing zone. Fish having a size greater than the spacing between the sizing bars 41 will be carried with the grader toward to the tank, while smaller fish will be able to swim through the grader. This is useful for grading the fish, for example, to separate the 25 fish according to size, or during harvesting, to harvest only those fish above a certain size. Different sized fish may be herded by changing the spacing between sizing bars 41. This can be achieved by replacing 30 gate 28 in support frame 26 with another gate having wider or reduced sizing bar spacing. Tank 32 is also provided with a moveable barrier in the form of a pusher 37, which is shown in Figure 2. Pusher 35 37, illustrated more closely in Figure 11, is similar in form to grader 25 in that it has a support frame 38 adapted to straddle the open tank and is supported by two WO 2008/104035 PCT/AU2008/000288 -8 pairs of wheels 39 with each pair resting on opposite floating members. Pusher 37 has a gate 40 that herds the fish toward an opening 34 in the tank and back into a growing zone after processing. Accordingly, in the 5 embodiment illustrated pusher 37 does not contain sizing bars. Pusher 37 is also used during harvesting to herd the fish to one end of the tank to allow the fish to be manually harvested using nets or by mechanical means, such as a fish pump. 10 Tank 32 in the embodiment shown is made of four modular and identical tank components 43 joined together with end walls 44 to form tank 32. In the preferred embodiment tank components 43 are manufactured in plastics, by rotational 15 moulding, and are joined by plastic welding. However the tank may be made of components of metal, composites or other suitable material. Figure 5(a) illustrates a tank component at one end 20 shorter than the others: tank components may be cut to size as desired. The modular nature of the tank components allows any length of tank to be constructed, depending on the desired configuration of the overall fish farm. 25 The floating members 12 are constructed by a series of modularly joined pontoons 50. In the preferred embodiment the pontoons are rotationally moulded in plastics, but may be made from other suitable materials including metal or composites. The pontoons are hollow. The upper surfaces 30 16 of the pontoons are designed as walkways to allow persons access around the entire floating structure. The surfaces 16 also support the wheels of the net and tank barriers 25, 38 and in some circumstances where distances are great, the pontoons may support 2-wheeled vehicles 35 such as motor bicycles.
WO 2008/104035 PCT/AU2008/000288 -9 Figure 1 illustrates the preferred configuration of the floating member structure, namely tank 32 centred and surrounded by pontoons 50 with rows of pontoons 50 (in this case five) extending in opposite directions laterally 5 of the tank such that each access opening 34 in the tank is aligned with a gap 14 between each pontoon row. This base system of modular components comprises one module of 50 pontoons and 4 tank components to form the floating structure illustrated in Figure 1. Further tank io components and pontoons may be added as desired. Figures 5(b)-5(d) illustrate how the tank 32 is attached to the stabilising pontoons surrounding it. The tank may not necessarily be buoyant itself but can rely on the is buoyancy of the pontoons. Figure 5(c) shows that tank 32 has a greater depth than the depth of the pontoons and that the tank is supported by hooking the tank edge 45, which is lipped, onto a ridge 52 on the external circumference of a pontoon. 20 Figure 5(d) shows an enlarged view of the tank/pontoon connection. As seen, tank edge 45 has attached on its underside a downwardly facing C-section plate 53 that hooks over and seats on ridges 52 on the surrounding 25 pontoons to stably interconnect the tank to the surrounding pontoons. Figures 8(b) and 8(c) illustrate C-sectioned side rails 47 adapted to insert into a corresponding recess 48 on the 30 pontoon upper surface 16 and are screwed into position. Rails 47, made of galvanised steel, allow for the connection of various ancillary and essential items to the pontoon including net hooks 23, handrails, automatic feeders 17, bird netting poles 49 and security gates. 35 Where the tank 32 locates over the edge of a pontoon, rail 47 is replaced by the C-section plate 53 which is attached to the tank edge 45.
WO 2008/104035 PCT/AU2008/000288 - 10 The pontoons 50 themselves are interconnected to each other to form the floating members 12. Each pontoon may be connected to another pontoon: end-to-end (as shown in 5 Figures 7(a) and 7(b)); side-to-end (as shown in Figures 6(a) and 6(b)); and side-to-side (as shown in Figure 9). The relative connection between the pontoons may be rigid or pivoting. A rigid connection ensures no relative 10 movement between the pontoons while a pivoting connection allows a degree of pivot between the pontoons to allow, for example, wave motion of water in ocean conditions which can strain and damage the pontoons if rigidly connected. When connected end-to-end the degree of pivot 15 of the pontoons will be about +4.5*-5.0*. When connected side-to-end the degree of movement will be about +3.7* 4.2*. The variety of connection configurations is possible by 20 way of a pinning system on each pontoon that comprises a first flange set 55 at one end and a second flange set 56 at the opposite end. Each first and second flange set contains two flanges protruding from the pontoon. Second flange sets 56 are also provided on each side of the 25 pontoon toward one end. There are therefore four points of attachment to each pontoon. Figures 8(a) - 8(f) illustrate a pontoon from various views. The flange sets 55, 56 are clearly seen in these drawings. 30 The first flange set 55 contains through-holes 57 and is designed to interleave with the second flange set 56 which contains corresponding through holes 58. An upper hole and a lower hole are provided on each flange. Pins 59 extend through one or both through-holes 58 in each flange and 35 through each corresponding hole through the interleaved flange sets. Caps 54 are placed on the ends of pins 59 to prevent the pins from falling out of the holes.
WO 2008/104035 PCT/AU2008/000288 - 11 To create a rigid connection, as illustrated in Figures 6(a), 6(b), 7(a) and 7(b), pins 59 are inserted through both upper and lower through-holes 58. For a pivoting s connection only one pin is inserted through either the upper through-holes or the lower ones. The pontoons 50 are moulded with water receiving grooves 51 on the underside of the pontoon to promote buoyancy and io structure stability in the water. The upper surface 16 of the pontoons is provided with a rough finish to create a non-slip surface. Aerators (not shown) aerate the water in the fish farm to 15 maintain oxygen saturation levels at optimum levels. The present fish farm provides a marked improvement in the yield of fish. There is minimal human handling because all transfer of fish is carried out by herding the fish 20 from area to area using barriers. Consequently, a greater number of fish can be transferred at any time by a single operator. This in turn reduces the amount of labour required, for example, one full time operator is able to monitor four modules, where one module consists of the 25 base fish farm illustrated in Figure 1. Compared to known fish farms where one operator is only responsible for 10,000kg of fish, with the present fish farm one operator can handle in the order of 360,000kg. 30 With the present fish farm the fish are far less stressed and fish mortality decreases. The modular nature of the fish farm allows it to be constructed to suit any water environment and any shaped water body. 35 It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention.
WO 2008/104035 PCT/AU2008/000288 - 12 In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary 5 implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.