AU752344B2

AU752344B2 - Shellfish containment device

Info

Publication number: AU752344B2
Application number: AU89363/98A
Authority: AU
Inventors: Kypros Kotzikas; Robert Bruce Nicolle
Original assignee: EVRIKA ENTPR Ltd
Current assignee: EVRIKA ENTERPRISES Ltd
Priority date: 1997-10-17
Filing date: 1998-10-16
Publication date: 2002-09-19
Anticipated expiration: 2018-10-16
Also published as: AU8936398A

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant/s: Evrika Enterprises Ltd S. Actual Inventor/s: Robert Bruce Nicolle; Kypros Kotzikas Address for Service: BALDWIN SHELSTON WATERS S 60 MARGARET STREET SYDNEY NSW 2000 Invention Title: "SHELLFISH CONTAINMENT DEVICE" The following statement is a full description of this invention, including the best method of performing it known °to me/us:- File: 21433.00 .e la SHELLFISH CONTAINMENT

DEVICE

Field Of The Invention The present invention relates to methods and apparatus for use in the controlled growth or cultivation of shellfish. More particularly, although not exclusively. the present invention relates to devices for aquaculture, for example in relation to growing shellfish such as oysters, scallops and the like.

Background To The Invention To the present time it is well known that shellfish may be grown in an open water environment using containment devices such as wire cages or systems whereby tha shellfish attach to ropes and are suspended under water.

S. 15 Such systems are not ideal as, in the example of cage containment, the containment devices are generally held in a static position. This results in a number of problems including fouling by marine growth whereby weed and natural fauna attach to the cage thereby reducing the flow of salt water through the growing environment.

Further, static location/orientation of prior art growing devices means that the 20 shellfish are not moved around significantly/continuously during their growth cycle.

Such effects can result in uneven growth of the shellfish with attendant reduced product yield and quality.

The prior art device shown in GB 2 170 083 allows for mechanical or tidal *25 movement of a shellfish containment cage. However, the device described in the abovementioned specification requires a fixed mounting which holds the cage in fixed relation to the sea bed thereby relying on the tide to effect "tumbling" of the shellfish. Such a construction is not practical in longline aquaculture installations where the containment vessels cannot be practically secured to a fixed object such as the sea bed.

Another disadvantage of known shellfish growing systems is that they can be difficult to locate and monitor. For example, cages, ropes and the like are generally suspended by floats and may be anchored to the sea floor. The containment device must be raised to the surface in order to examine and/or extract the shellfish. However, floating growing environments such as that described in US patent No. 4,328,764 are not ideal as they are suspended immediately below the surface of the water. Such devices can accumulate marine growth for the reasons discussed above.

It is an object of the present invention to provide shellfish containment device which makes efficient use of the growing environment, avoids clumping or excessive confinement of the growing shellfish, provides a more suitable environment for growing the shellfish in terms of water quality and reduces the buildup of extraneous marine fauna on the containment device itself or to at least provide the public with a useful Schoice.

Disclosure Of The Invention In one aspect the invention provides for a shellfish containment device including: a containment vessel having two complementary parts each with dimensions and geometry so that the containment vessel is capable of containing a plurality of shellfish and adapted to allow water to follow into and out of the *25 containment vessel; flotation means contained within the vessel for maintaining, in use, an upper "portion of the vessel above the water surface; where at least approximately one third of the height of the side of the vessel is above the water surface, and where the containment vessel is rotatable so that the upper portion can be submerged and a lower portion rotated to a position above the water surface.

to the first embodiment the flotation means is a float which is free to move within the vessel. According to a second embodiment the flotation means is a float

Q..

e fixed at a central location within the vessel. According to a third embodiment the flotation means is integrally formed in the walls of the containment vessel.

The containment vessel may be in the form of a closed, barrel shaped or rectangular box shaped vessel. The complimentary parts are preferably shaped so that they may be stacked within each other to save space during transportation.

The complimentary parts are preferably provided with inter-engaging formations along adjacent edges which enable the parts to be secured together by suitable fastening means.

According to a first embodiment complimentary formations may be provided at either end e..

of each part which may be secured together by fastening means which pass through aligned apertures when the two parts are brought together. The fastening means may 15 suitably be nuts and bolts, pins etc.

According to a second embodiment handles may be provided at each end of each part so that when the parts are brought together the handles may be secured together by rope or 0 other suitable fastening means.

The parts are preferably provided with apertures predominantly located in the base thereof to facilitate drainage. The apertures may be round holes, or slots or any other suitably shaped apertures.

0 0: 25 The invention also provides a method of suspending shellfish in water including: placing a plurality of shellfish in a first part of a containment vessel which is formed by two complementary parts, and which has a flotation means contained within the vessel for maintaining, in use, an upper portion of the vessel above the water surface, where at least approximately one third of the height of the side of the vessel is above the water surface, and where the containment vessel is rotatable so that the upper portion can be submerged and a lower portion rotated to a position above the water surface; placing one complementary part of the containment vessel adjacent the other complementary part so as to form a containing volume therebetween; securing the two parts together by fastening means; and securing the containment vessel to one or more lines extending along the surface of the water.

Preferably a float is placed within the containment vessel prior to securing the parts together. Preferably the containment vessel is secured between a pair of long lines.

.Brief Description Of The Drawings The present invention will now be described by way of example only and with reference to the drawings in which: Figure 1: shows a side view of a containment vessel with internal detail; Figure 2: shows an end view of a containment vessel with internal detail; Figure 3: shows a top view of a containment vessel shell according to a second 25 embodiment; Figure 4: shows a side cutaway view of the shell shown in figure 3; and Figure 5: shows an end cutaway view of the shell shown in figure 3.

Figure 6: shows a plurality of containment vessels when secured to a pair of long lines.

Figure 7: shows a perspective view of a containment vessel shell according to a third embodiment.

Figure 8: shows how two shells as shown in figure 7 may be secured together.

Figure 9: shows a side view of a containment vessel according to fourth embodiment.

Figure 10: shows a top or bottom view of the vessel shown in Figure 9; Figure 11: shows an end view of the vessel shown in Figure 9; Figure 12: shows a top or bottom view of a flotation means for use with the containment vessel of Figures 9 to 11; Figure 13: shows a side view of the flotation means of Figure 12; and Figure 14: shows an end view of the flotation means of Figure 12.

Referring to figure 1 an exemplary embodiment of a shellfish containment device is shown. The present example will be described in the context of a generally barrel shaped containment device having parts with flat base portions. However, it is to be understood that this configuration is not intended to be limiting. Other containment vessel geometries and dimensions may be suitable depending on the species which is to be grown therein, environmental conditions and other factors.

Referring to figure 1, a containment vessel 10 is formed from two parts 11 and 12.

These parts form complementary shells which are adapted to engage along their edges 40, 41. Each shell, in the present example, is a generally rectangular 'tray' .like shape.

o As can be seen from figure 2, when assembled, the shells form a barrel shaped S. containment vessel. The shells 11, 12 engage along their edges, in the present 20 example, by means of a raised lip 40 which is accommodated in a corresponding edge slot (not shown) in the edge 41. This locates the shells so that relative lateral movement is prevented.

Each shell incorporates drainage perforations 18. These are located in the base and 25 extend partially up the sides. The size of the holes is such that when the containment vessel is suspended in water, there is adequate flow-through of clean water as well as providing effective draining for when the containment device is removed from the water.

6 The shells also incorporate securing means 13, 14, 16, 17 in the form of handles.

Handle pair 13 and 14 is located at a first end of the shell 11 and 12 respectively with handle pair 16 and 17 located at a second end. These components serve to allow the containment device to be lifted as well as providing a means of locking the two shells together. To this end, apertures 42, 43, 44, 45 are located so that when the shells are assembled, fastening means, such as a section of rope 20, may pass through adjacent apertures 42, 43 or 44, 45 to be tied to secure the shells together. This, feature, combined with the engagement lip/slot in the shell edges, securely locks the containment device when the rope is secured.

A float 15 is located inside the containment vessel so that when the vessel is located in the water, it remains suspended in only a partially submerged state. The degree of submersion will depend on the size and buoyancy of the float.

15 In use, the required shellfish stock and float are placed inside of the shell halves. The °opposite half is placed on top to form the hollow containment vessel and the halves are secured together. The completed vessel 10 is then secured to long lines 21, 22 by ropes 23 as shown in Figure 6. Multiple barrels can be located on a long line structure as desired. Each containment vessel is self supporting and is kept in a partially submerged 20 state. The exposed part remains free of marine growth and the containment vessels may be rotated by rotating one line 21 with respect to the other line 22 to agitate the shellfish and expose alternate faces of the barrel, thus keeping them free of marine growth.

0i0, 0 The containment vessels are moved about in a partially submerged state by the natural action of the tide, wind and waves. This movement creates a suitable environment for shellfish growth by ensuring a continual supply of sea water and associated nutrients through the containment vessel while simultaneously moving 7 associated nutrients through the containment vessel while simultaneously moving the shellfish about. This movement allows the shellfish to develop a correct shape, form, appearance and other desirable growth characteristics. The present invention also is advantageous in that the shellfish containment vessels may be located relatively close to one another. There is no need to allow for space for locating floats on the longline between the devices as buoyancy is provided by means of the floats located inside the devices.

The longline structure can be turned over thereby tumbling the shellfish and exposing the previously submerged vessel half. The exposed part dries, which cleans any marine fouling.

The present shell construction example incorporates flat shell bases. This is particularly suitable for some species of shellfish which require particular stocking densities.

A second embodiment of the invention is shown in figures 3 to 5. This version incorporates a float 31 which is fixed in relation to the completed containment vessel. Each shell 30 includes a mounting recess 32 in which the end of the float 20 31 sits. When the corresponding shell half (not shown) is put in place, the float is secured in a position whereby the completed vessel is approximately only half submerged. Such an orientation may be preferred in some circumstances. The shell also incorporates drainage holes 38.

25 In the present example the float is shown as a separate component. However, the float may be formed integrally with the shell halves in such a way that the containment device is stable in water when upright or inverted. Further, the shell halves themselves may be composed of a material which exhibits positive buoyancy thereby providing an inherently buoyant containment vessel which may be inverted as required. For example, the walls of the shell halves may be sealed double walls.

The double walls may be air-filled hollow walls or may be filled with a suitable substance such as foam.

Figures 7 and 8 show a further embodiment of the invention. A shell half 50 is seen to be of generally rectangular construction which tapers towards the base to allow a number of shell halves 50 to be stacked within one another. Projections 51 and 52 of a first shape are provided at one end of the shell half and complimentary projections 53 and 54 are provided at the other end of the shell half. The design is such that another shell half 50 may be secured to a first shell half 50 so that the projections 51 and 52 engage with respective projections 53 and 54. Each projection 51, 52, 53 and 54 is provided with an aperture 55, 56, 57 and 58 there through.

15 Figure 8 shows the connection of projections 52 and 54 of respective shells when engaged together. A bolt 59 passes through apertures 56 and 58 and a nut 60 is secured thereto to fasten the two halves together. Other suitable fastening means such as pins etc may be employed. When the two halves are secured together a gap 62 exists between projection 52 and projection 54 to allow a line 61 e 20 to be engaged therein.

In use such a containment vessel may be engaged with a first line 61 by aligning slot 62 over line 61 and engaging line 61 therein. Line 61 may be fastened to the containment vessel by sections of rope etc. The entire vessel may then be rotated about line 61 through 180° so that the slot 62 at the opposite end of the vessel is positioned above a second line and can be engaged therewith. In this manner the containment vessel may be easily secured to a pair of long lines.

Another embodiment of the invention is shown in Figures 9 to 14. This version incorporates a float 63 which is adapted to be secured within vessel 64. Figure 9 shows vessel 64 comprised of two halves 65, 66 which are substantially identical to each other and are formed with lips 70, 71 adapted to engage with each other forming joint 67. Figure 10 shows a top view of the vessel of figure 9 and is identical to the bottom view. Raised elongate protrusions 68 serve to facilitate transport, stacking and drainage of the vessel 64 when not in use and provide strength for the base of each half 65, 66. Slots 69 allow movement of water into and out of the vessel 64 during use. Any number of slots or apertures of other shapes which allow sufficient movement of water may be used.

The end view of vessel 64 shown in figure 11 shows each half 65, 66 having a curved float locater edge 72 which is adapted to engage with slot 73 in the float 63 shown in figures 12 to 14. The float 63 has a cylindrical float body 74 connecting S. 15 end bodies 75. Figure 14 shows the cylindrical shape of the float body 74 (dotted line) and the elliptical shape of the end body 75. The float 63 is secured between the two halves 65, 66 of the vessel 64 by engagement of locater edge 72 with slot 73. The end bodies 75 are provided with protrusions 76 having apertures 77 serving as handles for movement and transport of the vessel 64. The float 63 may 20 be made of any substance which provides adequate buoyancy for the vessel 64.

Where in the foregoing description reference has been made to integers or components having known equivalents then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way of example it is to be appreciated that improvements and/or modifications may be made thereto without departing from the scope of the present invention as defined in the claims.

Claims

1. A shellfish containment device including: a containment vessel having two complementary parts each with dimensions and geometry so that the containment vessel is capable of containing a plurality of shellfish and adapted to allow water to flow into and out of the containment vessel; flotation means contained within the vessel for maintaining, in use, an upper portion of the vessel above the water surface; where at least approximately one third of the height of the side of the vessel is above the water surface, and where the containment vessel is rotatable so that the upper portion can be submerged and a lower portion rotated to a position above the water surface.

2. A shellfish containment device as claimed in claim 1 wherein the flotation means V is free to move within the vessel. o• C A shellfish containment device as claimed in claim 1 wherein the flotation means is fixed at a central location within the vessel.

4. A shellfish containment device as claimed in claim 1 wherein the flotation means S.i :is integrally formed in the walls of the vessel. A shellfish containment device as claimed in any one of the preceding claims wherein the flotation means includes one or more floats.

6. A shellfish containment device as claimed in claim 5 wherein the flotation means includes two floats.

7. A shellfish containment device as claimed in any one of the preceding claims S wherein the vessel is provided with two or more handles. 11

8. A shellfish containment device as claimed in any one of the preceding claims wherein the complementary parts are provided with a plurality of inter-engaging formations along complementary edges so that the parts can be secured together by suitable fastening means.

9. A shellfish containment device as claimed in claim 8 wherein the inter-engaging formations form two or more handles on the vessel. A shellfish containment device as claimed in any one of the preceding claims wherein the vessel is provided with apertures located in the base of the vessel to allow water to flow into and out of the vessel.

11. A method of suspending shellfish in water including: placing a plurality of shellfish in a first part of a containment vessel which is S 15 formed by two complementary parts, and which has a flotation means contained within the vessel for maintaining, in use, an upper portion of the vessel above the water surface, where at least approximately one third of the height of the side of the vessel is above the water surface, and where the containment vessel is rotatable so that the upper portion can be submerged and a lower portion rotated to a position above the water surface; placing one complementary part of the containment vessel adjacent the other complementary part so as to form a containing volume therebetween; securing the two parts together by fastening means; and securing the containment vessel to one or more lines extending along the 25 surface of the water.

12. A method as claimed in claim 11 wherein a float is placed within the containment vessel prior to securing the parts together.

13. A method as claimed in claim 11 wherein the containment vessel is secured between a pair of lines extending along the surface of the water.

14. A shellfish containment device substantially as herein described with reference to Figures 1 and 2, 3 to 5, 6, 7 and 8 or 9 to 14 of the accompanying drawings. A method as claimed in claim 11 substantially as herein described with reference to the accompanying drawings. DATED THIS 4 th DAY OF JUNE, 2002 EVRIKA ENTERPRISES LTD Attorney: STUART M. SMITH Fellow Institute of Patent Attorneys of Australia of BALDWIN SHELSTON WATERS C* C C C C