CN109068616B

CN109068616B - Abalone culture equipment and method

Info

Publication number: CN109068616B
Application number: CN201780023197.2A
Authority: CN
Inventors: 诺尔曼·波义耳
Original assignee: Nuo ErmanBoyier
Current assignee: Nuo ErmanBoyier
Priority date: 2016-03-16
Filing date: 2017-03-16
Publication date: 2022-07-15
Anticipated expiration: 2037-03-16
Also published as: KR20180122000A; AU2017233540A1; CN109068616A; KR102502935B1; CN114902983A; EP3429341A4; ZA201806655B; MA45308A; EP3429341A1; AU2017233540B2; WO2017156585A1; AU2022201952A1

Abstract

Improvements in apparatus and methods for raising abalone on shore and off shore environments. An onshore water tank for growth of abalone, the water tank comprising an elongate base comprising a plurality of prefabricated base portions; an upstanding wall parallel to a longitudinal axis of the elongate base; a plurality of channels connected to a water discharge and a water drain for delivering a flow of water to each channel, a plurality of tanks arranged in an array. An offshore submersible vessel defining a pen for abalone, the pen comprising an inner surface for receiving abalone thereon; one or more apertures configured to allow water to flow through the pen when the container is submerged in water, but not to allow abalone to pass therethrough; one or more feeding ports in the container wall; and one or more feed dispensers, each dispenser comprising a reservoir for abalone feed and a mouth portion configured for receipt at a respective feeding port.

Description

Abalone culture equipment and method

Technical Field

The invention relates to abalone culture equipment and a method. In particular, the invention relates to improvements in apparatus and methods for raising abalone on shore and off shore environments.

Background

Abalone is a very expensive food and its demand is increasing worldwide. To meet this continuing demand, abalone farms have been established to supplement the decreasing supply of wild abalone. While there are some final off-shore farms, the vast majority of abalone farms are land-based only.

In existing abalone farms, abalone larvae are usually allowed to settle on the surface of a plastic plate on which algae grow after spawning. The plates are then spaced apart in racks and loaded into a water tank for about 5-6 months, or until they grow to a size of about 10 mm. Factors such as sun exposure are carefully controlled during this "plate feeding" phase in order to balance the growth of seaweed on the plate with the growth of abalone. The young abalone are then moved to a so-called "plate tank" where they grow in a shallow tank through which high quality seawater continuously flows. Abalone is fed with prepared food that is specifically tailored for the different production stages and grows from about 10mm to about 25mm in size during the first 5-7 months in a plate-like water tank. Finally, approximately three years after spawning, abalone with a diameter of approximately 90mm can be put on the market and removed from the plate tank for processing.

Existing abalone farms require a large amount of infrastructure such as buildings, water tanks, pumping systems, etc. and are therefore very costly to operate. Indeed, the cost of producing approximately 200 tons of cultured abalone at current electricity prices is estimated to be around one million australian dollars. Furthermore, it takes approximately 3 years for abalone to grow to marketable sizes, and a large amount of water tank infrastructure is currently required almost all the way through. Thus, existing abalone farms are typically facing a production limit of around 200 tonnes per year and are therefore unlikely to be able to meet the ever-increasing demand for abalone worldwide.

Extending a traditional abalone farm to meet this demand is not without problems. For example, the large concrete tanks required for construction and their associated water supply and drainage systems are costly and time consuming to build, and can often be complicated by various factors, such as: uneven or unstable ground, existing buildings or infrastructure (which may impede concrete placement), etc. Furthermore, the water supply and drainage systems can be complex to operate and prone to failure.

Offshore farms in which abalone grows are known. In such farms, once the abalones have grown to over a certain size (typically about 50mm) on shore, they are transferred to an offshore growth facility where they are housed, for example, in a net suspended from a buoyant body (typically, the net is suspended from a circular buoyant body). A number of structures are located in the net which provide a place for abalone to hide and a surface on which they can rest (abalone does not rest on the net).

Although such off-shore farms may have less dependence on infrastructure than the above-mentioned on-shore farms, they still have a number of problems. For example, the food of abalone is spread into the pen, after which it falls through the water column and rests on the surface of the harbourage for consumption by abalone. However, as will be appreciated, a significant portion of the food may fall directly through the mesh and thus not be available to the abalone, thereby increasing production costs or reducing the growth rate of abalone. Movement in the water column may also cause food resting on the harbourage to be swept away before being consumed by the abalone. Finally, the risk of a predator being able to cross the net and eat the growing abalone is always present.

Offshore abalone farms must also usually be moderately firmly anchored to the seabed in order to minimize the risk of damage during storms or in high waves. The location of the farm in the water is therefore fixed, which can lead to environmental problems associated with reducing the amount of sunlight received by the seabed beneath the farm, or caused by contamination of the area around the farm with food that cannot be consumed by abalone.

Offshore farms using specially designed submersible abalone storage containers are known. However, it is difficult to supply feed to, and periodically inspect, abalone in such containers, and will typically require divers and/or other specialized equipment.

It would be advantageous to improve abalone culture apparatus and methods so that the productivity of abalone farms can be increased to meet the ever-increasing demand for abalone throughout the world.

Disclosure of Invention

In a first aspect, the invention provides a tank for growing abalone. The tank comprises an elongate base including an upstanding wall arranged substantially parallel to a longitudinal axis of the elongate base and defining a channel therebetween for receiving a flow of water. The elongate base comprises a plurality of preformed base portions adapted to be sealingly connected together.

As will be appreciated, building an abalone feeding tank (e.g. a plate tank) from prefabricated base parts can significantly simplify the building process compared to prior art processes. Such modular tanks would not require much of the preparation traditionally associated with large concrete pours, for example, and could use cranes or the like to transport the prefabricated base sections to the site, even near existing infrastructure (e.g., sheds or other slab tanks). Furthermore, the precast sections can be manufactured off-site and in a more controlled environment than is achievable on-site, and should therefore have a significantly higher and more stable quality.

In some embodiments, multiple prefabricated base sections may be substantially identical to one another in order to simplify the assembly process even further and reduce the number of different components required to build the tank.

In a second aspect, the present invention provides a prefabricated base part suitable for use in the cistern of the first aspect of the invention.

In a third aspect, the present invention provides a cistern system comprising a plurality of cisterns of the first aspect of the present invention arranged in an array.

In some embodiments of the third aspect, the tank system may comprise two tanks arranged in series along the longitudinal axis of their elongate base and the end of one tank is positioned adjacent to the end of the other tank (i.e., in an "end-to-end" arrangement). The tank system may further include a central trough that may be located between and sealingly connected to the elongated bases of adjacent ends of the tank, and that is selectively operable to deliver a flow of water into the passage of the tank or to drain water delivered into the distal end of the passage of the tank. In such embodiments, the amount of infrastructure (e.g., water piping and pumping equipment) required to operate the tank system can be minimized, thereby reducing the complexity and cost (both operational and construction) of the tank system.

The water tank system may also include an elevated platform above the central trough, which in some embodiments may be adapted to receive a water reservoir thereon. The reservoir may be operable to deliver water waves into one or more of the channels in order to flush the channels clean, in a manner similar to that done by waves in the natural environment of abalone.

In some embodiments, the water reservoir is slidable along a track disposed on the elevated platform such that it is aligned with a selected one or more of the channels in the water tank system. In some embodiments, the reservoir can be pivoted towards either tank so that water waves can be delivered to selected channels. In this way, the reservoir can be easily repositioned and pivoted (manually or automatically) so that it gradually flushes all the channels in the cistern system clean.

In some embodiments, the tank may further comprise abalone feeding equipment adapted to move along the length of each raceway and broadcast food into the raceways. The feeding device may slide, for example, along a track provided on an upright wall.

In some embodiments, the water tank may also include a dual water supply. As will be appreciated, a water supply failure (even for a short period of time) can result in the death of a large number of abalone.

In some aspects of the invention there is provided a tank or tank system for growing abalone comprising an elongate base comprising upstanding walls defining a channel therebetween for receiving a flow of water, wherein the tank or tank system further comprises any one or more of:

a plurality of prefabricated base portions adapted to be sealingly connected together;

a central trough located between and sealingly connected to the ends of adjacent elongate bases and selectively operable to deliver a flow of water into each channel or to discharge water that has been discharged into each channel at the distal end of adjacent elongate bases;

an elevated platform adapted to receive a reservoir thereon, the reservoir operable to deliver a water wave into one or more of the channels; and

an abalone feeding device adapted to move along the length of each of the corridors and broadcast food into the corridors.

In a fourth aspect, the invention provides a submersible container for storing abalone. The container comprises a container wall defining a pen for abalone, wherein the pen comprises an inner surface for receiving abalone thereon. The container also includes one or more apertures configured to allow water to flow through the pen when the container is submerged in water, but not abalone. The container also includes one or more feeding ports and one or more feed dispensers in the container wall. Each dispenser comprises a reservoir for abalone feed and a mouth portion configured for receipt at a respective feeding port, wherein the one or more dispensers are independently operable to dispense feed contained therein into the pen.

Such containers are well suited for use in offshore environments, such as those where the container is suspended from a floating body or long rope. The natural movement of the water causes the water to flow through the vessel, which provides a continuous source of oxygenated water for the abalone resting on the inner surface, without all the requirements of on-shore growing facilities, such as a plate-like water tank and continuous water pumping.

Furthermore, providing the submersible vessel with a feed dispenser can advantageously extend the time between inspections of abalone in the vessel. Although the growing abalone should always be examined regularly, in such embodiments the time between examinations may be extended (e.g. by up to one month). This is a significant improvement over some existing submersible vessels which require retrieval from the water about every week to replenish the feed of the abalone, or which require a diver to couple a hose through which the abalone feed can be pumped from the boat into the vessel.

In some embodiments, one or more dispensers can be independently operable to dispense feed contained therein into the pen at a predetermined time. In some embodiments, for example, the container can include two or more feed dispensers, the plurality of feed dispensers being adapted to dispense feed contained therein into the pen at different times (e.g., at different predetermined times). Such embodiments may advantageously ensure more stable food delivery, which may help prevent waste of food.

In some implementations, the pen can be configured to receive therein means providing a further inner surface for receiving abalone thereon. Since the number of abalone that can be stored within the pen depends on various factors, including the amount of surface area available, increasing the inner surface area means that more abalone can be grown in the container.

In some embodiments, the members may be substantially planar, which will help when removing abalone, as there are no narrow corners in which they may hide. However, as will be appreciated, it is desirable to maximise the internal abalone receiving surface area as much as possible. Thus, when the members are foldable to fit within the fence, members larger than the fence can be used. In some embodiments, the member may be foldable a plurality of times so as to define a plurality of further inner surfaces for receiving abalone thereon. The number of abalone can thus be maximised for a given volume, thereby contributing to a further improvement in the efficiency of the farming process.

In some embodiments, the container wall may comprise an inner wall and an outer wall with a cavity therebetween. The cavity may for example be adapted to receive air, water or sand (or a combination thereof) in order to adjust the buoyancy of the container.

In some embodiments, the container may be openable for access to abalone in the pen. Removal of abalone from a surface can be difficult, and even more difficult, if the abalone can hide in hard-to-reach recesses. Therefore, anything done to improve access to the abalone in the container will help to improve the efficiency of the farming process.

In a fifth aspect, the invention provides a feed dispenser for use with the submersible container of the fourth aspect of the invention. The feed dispenser comprises: a reservoir configured to hold a feed for abalone; a mouth portion configured to be received in one of the feeding ports of the container; and a gate that is movable from a closed position to an open position upon receiving a signal (e.g., a signal generated at the end of a predetermined time or a signal generated by an external source). When the gate is moved from its closed position to its open position, feed contained in the reservoir is dispensed into the pen.

In a sixth aspect, the invention provides a method for growing abalone in an offshore location. The method comprises deploying one or more of the submersible vessels of the fourth aspect of the invention on a long rope anchored to the sea floor, and periodically retrieving each of the one or more submersible vessels and inspecting the abalone contained therein (e.g. for predators, expected growth, any mortality, etc.).

Using an offshore location to raise young abalones would vacate the onshore tank infrastructure for the next round of abalone raising, thereby reducing costs associated with long-term use (up to 3 years) of large tank infrastructures and enabling the growth of more generations of abalones. Furthermore, due to the natural movement of water around the vessel, there is no need to actively pump seawater through the submersible vessel (i.e. as required in an onshore plate tank), which significantly reduces the costs associated with operating the pumping system (in terms of the abalone grown). Furthermore, the container of the invention, particularly when held in an overhanging environment, can significantly reduce predation by keeping abalone out of reach of predatory mud animals (such as asterias and the like).

In embodiments where the submersible container includes a feed dispenser, the method of the invention may further comprise replacing any empty feed dispenser with a full feed dispenser.

In some embodiments, one or more submersible vessels may be retrieved using a retrieval device suspended on the side of the boat. The retrieval apparatus may for example be operable to lift the container from the water, position the container on the deck of a boat for inspection of abalone contained therein, and then place the container back into the water. In such embodiments, the abalone is accessible to persons onboard the ship, and divers are not necessary.

Drawings

Embodiments of the invention will be described in more detail below with reference to the accompanying drawings, in which:

FIG. 1 shows a partially exploded perspective view of a cistern system according to an embodiment of the present invention;

FIG. 2 shows a cross-sectional side view of a channel for delivering water to a tank or a trough for draining water from the channel, according to an embodiment of the present invention;

FIG. 3 shows a partially exploded perspective view of the tank and water tank of FIG. 2;

FIG. 4 illustrates a partially exploded perspective view of a center tank of a cistern system according to an embodiment of the present invention;

FIG. 5 shows a cross-sectional side view of a center tank of a cistern system according to another embodiment of the present invention;

FIG. 6 shows an exploded perspective view of a cistern system according to another embodiment of the present invention;

FIG. 7 illustrates an embodiment of a water supply system for use with a water tank system according to an embodiment of the present invention;

FIG. 8 shows an array of water tanks of an embodiment of a water tank system according to the present invention;

figure 9 shows a perspective view of a submersible container for storing abalone according to an embodiment of the invention;

figure 10 shows a perspective view of a plurality of submersible vessels for storing abalone in a stacked arrangement according to an alternative embodiment of the invention;

Figure 11 shows a cross-sectional side view of the submersible vessel of figure 10 with the means for receiving abalone thereon housed within a fence;

FIG. 12 shows a perspective view of the container and components of FIG. 11, with the container in an open configuration;

figure 13 shows means for receiving abalone thereon, in accordance with an embodiment of the invention;

FIG. 14 shows a perspective view of a feed dispenser for use with a submersible container according to an embodiment of the invention with the lid in a closed configuration;

FIG. 15 shows the feed dispenser of FIG. 14 but with the lid in its open configuration;

FIG. 16 shows a perspective view of the feed dispenser of FIG. 14 from the other end thereof;

FIG. 17 shows a cross-sectional view of the feed dispenser of FIG. 14;

figure 18 shows a cross-sectional view of the feed dispenser of figure 14 after insertion into a submersible container for storage of abalone according to an embodiment of the invention;

figure 19 shows a side view of a plurality of submersible vessels deployed offshore on a long rope for storing abalone according to an embodiment of the invention;

FIG. 20 shows a close-up view of a portion of the long cord of FIG. 19;

FIG. 21 shows a perspective view of a boat for retrieving the submersible vessel of FIG. 19 for inspection; and is provided with

Figure 22 shows a rear view of the lifting device of the boat shown in figure 21.

Detailed Description

The present invention relates to apparatus and methods that can be used to improve the efficiency of on-shore and off-shore abalone farms. The present invention will be described in more detail below.

Water tank and water tank system

In one aspect, the invention provides a water tank for growing abalone. The cistern comprises an elongate base including an upstanding wall arranged substantially parallel to the longitudinal axis of the elongate base and defining a passage therebetween for receiving a continuous (in use) flow of water therethrough. The elongate base comprises (and in some embodiments is defined by) a plurality of preformed base portions adapted to be sealingly connected together. In another aspect, the present invention provides a cistern system that includes a plurality of these cisterns arranged in an array. In yet another aspect, the invention provides prefabricated base sections for use in these tanks or tank systems.

As discussed above, abalone farms traditionally include a plate-like water tank rearing stage in which abalone grows from larvae to a size that can be brought to market. Such plate tanks are typically long, shallow concrete tanks, approximately 18 meters long, 2.5 meters wide and 20cm deep. To create a suitable growing environment, about 3 litres of fresh seawater per second is pumped through the tank, the depth of the water being maintained at about 75mm (sufficient to cover the abalone in the tank).

The water tank of the present invention includes an elongated base having upstanding walls defining a channel therebetween for receiving a flow of water. The elongate base may be of suitable length (e.g. between about 10 and 30 metres or between about 15 and 25 metres), but is preferably about 18m long, similar to a conventional plate-like cistern. Experiments and experiments have shown that the oxygen concentration in water flowing through a plate tank containing abalone tends to drop below the desired level after about 18 m. Thus, a tank of approximately 18 meters in length substantially prevents the anoxic water from flowing past the abalone at the distal end of the tank.

The elongate base may include any number of channels. Typically, the elongate base comprises a plurality of channels in order to maximise the number of abalone that can grow in the tank. Each of the channels may have any suitable width (e.g., between about 1 and 5 meters or between about 2 and 4 meters), while the tank has a corresponding width. However, similar to the channel provided in the conventional plate-shaped water tank, the channel width is preferably about 2.5 m. When the elongate base has a plurality of channels, the channels may have the same or different widths. In a particular embodiment, the or each channel is about 18m long and about 2.5m wide.

The upstanding wall is arranged generally parallel to the longitudinal axis of the elongate base and may have any suitable height. For example, in some embodiments, the upstanding wall may be about 20cm high, as is the case with conventional plate-like tanks. Typically, the upstanding wall extends substantially the entire length of the elongate base, but some retraction or extension may provide advantages, such as those discussed below. The upstanding walls can have any suitable thickness (i.e., width) so long as they are suitable for the purposes described herein. Too narrow, their structural integrity may be compromised during construction of the tank or during subsequent operations. Too thick, they require an excess of material to form and also reduce the width of the abalone-containing channel and unnecessarily increase the overall weight of the elongate mount. An upstanding wall having a width of about 150mm has been found to be effective.

Any number of prefabricated base parts may be used to form the elongate base (and thus the cistern) of the present invention. The elongate base may for example comprise two or more prefabricated base parts which are sealingly connected together in an edge-to-edge manner so as to provide a wider cistern with additional channels. The elongate base may, for example, comprise two or more prefabricated base parts which are sealingly connected together in an end-to-end manner so as to provide a longer channel or to enable the use of shorter prefabricated base parts.

In certain embodiments, the width of the elongate base is one or two prefabricated base portions. In certain embodiments, the length of the elongate base is two prefabricated base portions. This configuration has been found to provide a good balance between tank size and relative ease of construction, as the pre-fabricated base sections are of a size that is easily transported and maneuvered into place using conventional vehicles and machinery.

In view of the conventional length and width of the plate-like tank, it may be convenient to use prefabricated base parts having a length of about 9m in such embodiments. Two of such base portions may be combined to provide a channel of about 18m length. Such prefabricated base parts have a length that is easily transported from its place of manufacture to the abalone farm using conventional transport means. Such embodiments provide a balance between factors such as the tank ideally having a minimum number of base portions but still having useful dimensions, while the prefabricated base portions can still be relatively easily transported and subsequently positioned on site.

When the channels in a conventional plate-like tank are about 2.5m wide, the prefabricated base part may comprise up to four channels and still be transported using conventional vehicles and machinery. However, two channel wide prefabricated base sections may be preferred in some situations because they may be easier to handle. The prefabricated base part with the two channels will have a width of about 6m, which as discussed above, has dimensions enabling transport using conventional transport means. A prefabricated base part with four channels will have a width of about 11m, which is of a size that (just) can be transported using conventional transport means, but will be heavier and more difficult to handle, and thus less suitable for some applications.

The bottom of the channel may be substantially smooth or may include raised members on which abalone tends to prefer to locate itself. Such raised members provide shelter for abalone and simulate a more natural living environment. Although the raised members may have any form and orientation, by the time abalone in the tank is harvested, it may be easier to remove abalone from above by the generally linear shape of the raised members extending generally parallel to the length of the channel (i.e. generally parallel to the longitudinal axis of the elongate seat).

The prefabricated base part may be made of any suitable material. In some embodiments, the prefabricated base part is made of concrete. As will be appreciated, concrete is a particularly suitable material for applications like this due to its strength, durability, resistance to UV light and relatively low cost. Other suitable materials include plastics (e.g., molded plastics) having suitable strength and durability.

In embodiments where the prefabricated base portion is made of concrete, the concrete must have a thickness that imparts sufficient strength so that the base portion can withstand lifting during construction and assembly of the tank or tank system, and subsequently withstand the weight of the abalone and water flowing through the raceway. The floor of the base portion may for example be at least 100mm thick, at least 130mm thick or at least 150mm thick, depending on various factors such as the relative dimensions of the base portion and the resulting tank, the amount of abalone to be grown in the tank, etc. Similarly, the upstanding wall (and other prefabricated components described herein) must have a thickness commensurate with its end use.

To simplify the construction of the cistern or cistern system, the prefabricated base parts may be substantially identical to each other. The reduced number of components is another factor that may contribute to reduced manufacturing costs. However, in alternative embodiments, each of the preformed base portions may be the same or different from one another, so long as they can be sealingly connected together to form an elongate base.

The preformed base portions are adapted to be sealingly connected together. Any method of forming a substantially fluid tight seal between the joined base portions may be used. For example, in some embodiments, an end of one of the preformed base portions may comprise a protrusion configured to be sealingly received in a corresponding recess at an end of another of the preformed base portions. Such an arrangement may be provided in the form of: an extended protrusion configured to rest on a corresponding retracted protrusion of an adjacent portion. Alternatively, tongue and groove type structures may be used.

If the surfaces of the base portions forming the seal are sufficiently smooth (due to the relatively heavy weight of one base portion bearing on the other), then sealant may not be required. However, in some embodiments, a sealant may be used to improve the watertightness of the seal between the base portions. Any waterproof sealant material may be used as the sealant, especially one having a degree of compressibility. Suitable encapsulants include, for example, silicon-based encapsulants.

In some embodiments, the prefabricated base portion may be built in situ with the pipes and other components (e.g., poured into the concrete base portion). Providing piping (etc.) for the tank and tank system inside the base portion can significantly simplify tank construction and significantly reduce the likelihood of leaks (e.g., because exposed pipes are damaged or mis-aligned during installation).

The cistern and cistern system of the present invention may also include additional components that enable water to flow through its passages. Examples of such components are described below.

In some embodiments, one end of the elongate base may be adapted to be sealingly connected to a water discharge for delivering a flow of water to the or each channel. In some embodiments, the other end of the elongate base (i.e., its distal end) can be adapted to sealingly connect to a drain. In this way, a water tank capable of providing a flow of water over abalone in its channels may be relatively easy to build using additional modular components. In some embodiments, the prefabricated base portion may include the necessary features (e.g., protrusions and complementary recesses) for connecting the elongated base to the water discharge and drain. Alternatively, these features may be provided separately from the prefabricated base part.

The water discharge may for example comprise a trough extending across the width of the elongate base and wherein water delivered into the trough then flows into the or each channel. The drain may for example comprise a trough extending across the width of the elongate base and wherein water that has flowed through the or each channel drains into the trough. Slots extending across the width of the elongate base can deliver a relatively uniform flow of water through each channel in the water box.

The elongate base may be sealingly connected to the water discharge and drain using any suitable mechanism (e.g., as discussed above in the context of sealingly connecting base portions). Typically, the width of the discharge and drain will be substantially the same as the elongated base, but in some embodiments they may be longer or shorter than the width of the elongated base, so long as water cannot leak from the tank.

The water discharge and drain may be constructed of any suitable material, such as concrete or plastic. While the water drains and drainers will typically be provided in a prefabricated form (i.e., with a prefabricated base portion) so as to conform to the modularity of the tank, it has been noted that they may be separately constructed on site in some embodiments (e.g., after transporting the prefabricated base portion and constructing an elongated base of the tank).

The channels of the water discharge and the drainer may have the same structure or different structures. In some embodiments, one or both of the slots has a first edge and a second edge, wherein the first edge is adapted to be sealingly attached to an end of the elongate base. The first edge is lower than the second edge and water introduced into the tailer trough therefore overflows on that side of the trough and thus enters the channel, rather than overflowing over the second edge. Similarly, water draining from the channel into the gutter (i.e. over its first edge) cannot overflow over its (higher) second edge, but rather causes it to flow into a drain (described below).

In some embodiments, the water discharger and the water drainer may be provided in such a form that their functions can be switched. That is, the water discharger (e.g., a slot at one end of the elongate base) may switch such that it becomes a water discharger, while at the same time, the water discharger (e.g., a slot at the distal end of the elongate base) may switch such that it becomes a water discharger. This switching enables the direction of water flow within the channel to be alternated, mimicking tidal flow and assisting in feeding and oxygenating abalone, regardless of their position in the channel (abalone at one end of the channel will change from receiving the least oxygenated water to receiving the most oxygenated water).

The tank may be mounted on the ground (or any other surface) in any suitable manner. For example, existing slab-like water tanks are typically in the form of a concrete slab formed by pouring concrete into a formwork suitably positioned on the ground. However, such tanks may eventually be uneven (which may lead to problems with water flow, etc.) or may break due to subsequent earth movement. Thus, while the tanks of the present invention may be located on the ground, they may also be adapted to be mounted to one or more posts (e.g., the tank may include a recess or the like in which the post may be received). The stanchions may be arranged prior to transporting the prefabricated base parts such that the stanchions support the base parts at the intended height while the base parts are engaged to form the elongated base and thus the water tank. The prefabricated base part can be suspended, for example, directly after transport with a crane, onto such a column. As will be appreciated, this method of construction does not require the laying of a foundation, and therefore may even reduce the cost of constructing the tank or tank system.

Also advantageously, the use of the stanchion will enable the elongate base (or the like) of the cistern/cistern system to be in a raised position from the ground. Such a raised position may be more ergonomic for the worker, as the worker would not need to bend over or crouch to ground level in order to manually handle the material, etc. in the aisle. In fact, the tank is at a working height convenient for the workers. Furthermore, the piping associated with the delivery and discharge of water to and from the channels may be located above the ground (typically above the ground), rather than having to be buried below the ground in order to have a sufficient head (as is the case with tanks located above the ground). As will be appreciated, not only will this reduce the amount of work required to install the tank of the present invention (e.g., will not be required to trench the pipeline below ground), but any leaks in the pipeline will be more easily detected and repaired. General maintenance of the pipeline is also greatly simplified if the pipeline is not buried.

In some embodiments, the struts may be adapted such that the distance they protrude from the ground is adjustable. The screw legs are screwed into the ground, for example, and once screwed firmly into the ground may be screwed up or down to adjust their relative height. Such helical struts can help to significantly reduce the time of construction of the tank system and result in less material being required.

The support on which the base portion is mounted may also be used to support the water discharge and drain described above.

In an embodiment of the cistern system of the present invention, the cistern system comprises a central tank and two cisterns arranged in series along the longitudinal axis of the elongate base thereof, and the end of one cistern is positioned adjacent to the end of the other cistern. The central slot is located between and sealingly connected to the ends of adjacent elongate bases (e.g. in the manner discussed above), and is selectively operable to deliver water flow into the channel(s) or to discharge water delivered into the channel(s) at the distal end of the adjacent tank (i.e. to enable the flow of water through the channel to be reversed, as described above). As will be appreciated, this embodiment of the tank system may be applicable to any even number of tanks (e.g., tanks arranged side-to-side and end-to-end with a central trough therebetween).

The array of water boxes in this embodiment is advantageous because providing a central trough can reduce the total number of components required to operate the water box system. Furthermore, the footprint of two tanks arranged in this way is smaller than the footprint of two tanks arranged separately, which may be advantageous in space-limited locations.

The central trough may have the same features as the above-described drains and drains, but its two edges may need to be of similar height (assuming adjacent tanks are at the same height).

The cistern system (or indeed, a plate-like cistern system with a cistern that is not formed from prefabricated base parts) may also comprise an elevated platform above the central trough. The elevated platform may be adapted to receive a reservoir thereon, wherein the reservoir is operable to deliver a water wave into one or more of the channels. This water wave is similar to the waves that occur in the natural environment of abalone and can be used to flush the channel clean and for abalone to grow more muscle mass. In addition, the periodic flushing of the pathway may assist in oxygenating and feeding the abalone. Because each tank (or even each channel) may have separate water supplies and drains to help prevent cross-contamination, the reservoir may be adapted to isolate water waves to the separate tanks or channels.

The water reservoir may be movable along the elevated platform, for example by sliding along rails provided on the elevated platform. It may be relatively easy to move the reservoir (even when full of water) to align the reservoir with a selected channel or channels in the water tank system. Once in position, the reservoir may be pivotable towards a channel in any of the adjacent tanks in order to deliver a wave to a selected channel of a selected tank. In this way, a single reservoir may be used to provide water waves to a potentially large number of channels. The reservoir may have a width substantially the same as the width of the channel so that the water waves span the entire width of the channel. Alternatively, some underlap or overlap may be provided.

It should be noted that the water reservoir described above may be positioned at a location other than the central channel of the water reservoir system (e.g., at the distal end of the adjacent water reservoir).

The water tank system (or indeed, a plate-like water tank system having a water tank that is not formed from prefabricated base portions) may also include an abalone feeding device adapted to move along the length of each raceway and broadcast food into the raceways. Such feeding apparatus may be automated (thereby saving labour costs), may be able to access pathways that are difficult for humans to access, and may be able to more reliably and stably dispense abalone food.

Any method of the abalone feeder that is capable of distributing food to all abalone in the water tank system can be used. In some embodiments, for example, the feeding device can slide along a track disposed on an upstanding wall between the channels. Such a rail network may extend throughout the cistern system, wherein the rails provided on the individual base portions are aligned after the cistern system has been built. Thus, the automated feeder can be programmed to travel around within the tank system and dispense food at the appropriate time.

The cistern system (or indeed, a plate-like cistern system with a cistern that is not formed from prefabricated base parts) may also comprise a walkway along which a person may walk to access a passage that is inaccessible or difficult to access from the side of the cistern system. The walkway may be defined, for example, by the upright walls of the elongate base (if wide enough). Alternatively, the walkway may be a separate member wide enough to walk on and be adapted to be connected to the cistern system in a suitable manner. In some embodiments, for example, the walkway may be adapted to connect to one or more of the upright walls in the elongate base.

The tank system (or indeed, a plate-like tank system having a tank not formed from prefabricated base parts) may also include a dual water supply to prevent the massive death of abalone in the event of a failure of the main water supply.

The present invention also provides a process for operating the above-described tank system, for example, in the manner described below.

Submersible container for storing abalone

In another aspect, the invention provides a submersible container for storing abalone. The container comprises a container wall defining a pen for abalone, wherein the pen comprises an inner surface for receiving abalone thereon. The container also includes one or more apertures configured to allow water to flow through the pen when the container is submerged in water, but not to allow abalone to pass therethrough. The container also includes one or more feeding ports and one or more feed dispensers in the container wall. Each dispenser comprising a reservoir for abalone feed and a mouth portion configured for receipt at a respective feeding port, wherein the one or more dispensers are independently operable to dispense feed contained therein into the pen

Advantageously, the vessel is adapted for offshore deployment, thereby freeing up limited onshore resources so that the overall productivity of abalone can be increased. Furthermore, abalone growing in a more natural environment draws oxygen and at least some nutrients from the surrounding water, thereby eliminating the need for circulation pumps and the like and possibly reducing the amount of additional food required. Furthermore, the feed dispenser may be used to extend the time between inspections of the containers without having to resort to the complex and costly procedures currently used in some offshore abalone farms.

The submersible vessel can be of any suitable size, shape and configuration, so long as it is capable of storing abalone in an environment where food and oxygenated seawater are readily available. The container may for example be elongate. The container may for example be substantially tubular. A container having such a shape may be easier to physically handle and more suitable for holding more abalone, while still allowing seawater to flow therethrough. Other advantages of the tubular container will be described below.

In some embodiments, for example, the length of the container may be between about 500mm and 4000mm (e.g., between about 1000mm and 3000mm or about 2200 mm). In some embodiments, the container may have a diameter (or cross-sectional length where the container is non-cylindrical) of between about 1000mm and 500mm (e.g., between about 800mm and 400mm or about 620 mm).

The container may be made of any suitable material, bearing in mind that the container will be immersed in seawater for much of its useful life and will be subject to the harsh conditions associated with the movement of water and periodic collection, inspection and redeployment, as described below. Relatively rigid plastic materials are therefore preferred (especially because these materials are relatively easy to form using rotational molding, blow molding, etc.). The container may be made of polyethylene (e.g., food grade polyethylene), for example, using rotational molding techniques (which are relatively inexpensive). The container may also be predominantly black in some embodiments, which provides a dark environment that is preferred by abalone.

The container also includes one or more apertures configured to allow water to flow through the pen when the container is submerged in water. Typically, at least two apertures will be required in order to achieve a cross flow of water through the pen, but one large aperture may also be able to provide this function. In embodiments where the submersible vessel is elongate, the one or more apertures may be provided by apertures on opposite ends of the vessel. In some embodiments, the vessel may comprise two (or more) primary pores (typically larger pores, but they may be smaller pores arranged in a manner to receive a large flow of seawater therethrough) and a number of secondary (typically smaller) pores.

The aperture does not allow abalone to pass therethrough, otherwise abalone may be able to escape from the container (or predators may be able to enter the container). Blocking the passage of abalone through the aperture may be achieved in any suitable manner. The pores may be provided, for example, in the form of a plurality of micropores in the wall of the container. Alternatively, the apertures may be provided in the form of a screen covering larger apertures in the vessel wall (e.g. at either end thereof in the case of an elongate vessel). This screen allows nutrients and water to freely enter and flow through the pen while retaining abalone. In some embodiments, the screen may be provided in the form of a rigid plate of material adapted to be received within a recess in the vessel wall (which may help protect the screen from damage).

Such a screen may be formed of any suitable material, again keeping in mind its intended use. For example, the screens must be corrosion resistant and stiff enough to withstand the potentially rough seas and impacts when in water and when loaded/unloaded from a boat. One suitable material for forming the screen is stainless steel, for example about 1.5mm thick stainless steel perforated with 4mm holes, wherein 40% of the surface area is open. A screen of approximately 1.5mm thickness has been found to be ideal as this is the thickness that abalone can self-clean. In use, abalone can feed on the mesh and their mouth can actually access the aperture so that they may feed on algae etc located in the aperture. Such ingestion may help prevent (or at least delay) biofouling of such screens, thus allowing water to flow through the vessel for a longer period of time. If the screen is much thicker than 1.5mm, the abalone may not be able to actually touch the outermost side of the screen and thus biofouling of the outermost side may occur. However, if the screen is much thinner than 1.5mm, its strength may be compromised.

A sieve with a pore size of about 4mm (± 1-2mm) may also be beneficial because it can prevent food freshly taken for abalone from immediately escaping the pen. In effect, the food is left in the pen where it is available for consumption by abalone. However, over time, the food dissolves and thus becomes smaller, so that it can then pass through suitably sized holes in the sieve screen. In this way, the earlier food that has not been consumed by abalone will tend to be flushed out of the pen by the seawater flowing through the pen.

Similarly, a screen having a pore size of about 4mm (± 1-2mm) may also be beneficial because it may prevent young predators from entering the pen, it being conceivable that during the course of a year (e.g., during the first offshore growth stage described herein) young predators may grow to a size where they may threaten the growing abalone. For example, it is possible that some predators may be located in the water column (but they will typically be found on the sea floor) and may come into contact with the submersible vessel. In such cases, predators who are large enough to eat abalone cannot pass through the screen, but young predators may be able to pass through and may not be noticed during the periodic inspection described herein. However, when abalone is removed from the container for sorting or marketing after a period of 12 months (after the first or second offshore growth stage respectively), young predators who may be able to enter the pen will be discovered at this time.

In embodiments where the submersible vessel is a cylindrical vessel 2200mm long and 620mm in diameter, the submersible vessel may also comprise two 600mm diameter and 1.5mm thick screens formed from 316 stainless steel perforated with 4mm holes and having 40% open area. These screens may be located at either end of the vessel, and the vessel may be provided with circumferential recesses at a short distance from its end into which the screens may be received.

The submersible vessel may also have a number of apertures along its length to further increase the flow of water through the pen. Such apertures may be covered by rectangular side screen sections 400mm wide, 200mm high and 1.5mm thick and again formed from 316 stainless steel perforated with 4mm holes and having 40% open area.

The inner surface of the pen is adapted to receive abalone thereon. As abalone tends to position itself against protrusions or hide in corners or the like, surfaces are typically adapted to receive abalone thereon by including many protrusions on the surface. In some embodiments, for example, the inner surface may comprise a plurality of ribs on the container wall, and the abalone may rest against the plurality of ribs. The ribs may for example be arranged substantially parallel to one another to make it easier to subsequently remove the abalone from the pen (e.g. for sorting or marketing). In embodiments where the container is elongate, for example, the ribs may be arranged to be generally aligned with an elongate axis of the container. Such protrusions or ribs may also help to distribute food and nutrients evenly throughout the pen, as such food and nutrients cannot collect at the bottom of the pen.

Other ways of increasing the available surface area within the pen and on which abalone can be received (and thus how the storage capacity of the container is increased) will be described below.

Any suitable technique may be used to access the abalone contained within the submersible vessel. For example, if a person only needs to visually inspect abalone to ensure that no bad things happen to them, a simple visual inspection through the aperture (or feeding port, as discussed below) may be sufficient. However, it will often be necessary to inspect the abalone more rigorously or even actually approach the abalone within the container. Thus, in some embodiments, the container may be openable to access abalone in the pen. The container may for example comprise one or more gates which once opened enable access to abalone within the pen. The container may be openable, for example in some way, thereby making the entire pen readily accessible, which may help to significantly improve the ease with which abalone can be observed or removed.

In some embodiments, for example, a container may include first and second portions that are connected or connectable (e.g., hinged or otherwise pivotable) on one side thereof and movable between a container open configuration and a container closed configuration. In such embodiments, only a relatively simple opening action (possibly in combination with an unlocking action) may be required to open the container and fully expose the enclosure. In embodiments where the container is elongate, the portions may be connected or connectable (e.g. hinged) together at the longitudinal edges, thereby further simplifying the opening action.

The first and second portions may have any shape and may be adapted to be interconnected by any suitable mechanism. In some embodiments, the first and second portions are substantially identical, as this will simplify the construction of the portions (e.g., they may be able to be formed from the same mold). However, this need not be the case in all embodiments, and the first portion may be different from the second portion. The container may also include a third portion (or the like) connected or connectable to one or both of the first and second portions.

Any suitable locking mechanism may be used to hold the first and second portions in the closed configuration. For example, one or both of the first and second portions may have a mechanical interlock (or a plurality of such mechanical interlocks). The mechanical interlock may be, for example, a latch that can be grasped by an operator to unlock the lock. Such latches will typically be recessed into the container wall to make it difficult to inadvertently open. Such a recess will also reduce the likelihood of damage to the hinge in use (most likely during collection and deployment of the container from a boat).

In some embodiments, the plurality of submersible containers are stackable when in the container open configuration. Stacked containers will generally occupy less space and therefore be more efficient to store when not in use or when transported.

In some embodiments, the submersible vessel may be adapted to be received on a surface in a highly stable manner (i.e., upon leaving water). As will be appreciated, a container that may be able to roll (or otherwise move relatively easily) when used on a boat would be unsafe. The container may, for example, be adapted so as to form at least three separate points of contact with the ground when in the closed configuration. The container may for example be adapted so as to form at least six contact points with the ground when in the open configuration. A protrusion on the outer wall of the container may be used to provide this stability.

The walls of the submersible vessel may have any suitable configuration, bearing in mind the harsh conditions that the vessel may be subjected to, as discussed above. In some embodiments, for example, the container wall may comprise an inner wall and an outer wall with a cavity therebetween. This double-walled construction imparts strength to the container, but may also provide other useful features. In some embodiments, for example, the cavity between the inner and outer walls may be adapted to receive air, water, sand (or any other suitable material thereof), or a combination thereof, in order to adjust the buoyancy of the container.

One or more inlets may be provided for pumping water (or the like) into and out of the cavity between the inner and outer walls, for example in the form of a drain plug which may be screwed into and out of a complementary threaded aperture in the container wall. The inner and outer walls may also be formed such that they abut each other in a number of locations, which helps to strengthen the container and may make it easier to form (e.g., by molding)

As mentioned above, it will often be desirable to increase the available surface area within the pen and on which abalone can be received, in order to increase the abalone storage capacity of the container. Indeed, the more surface area in the pen, the greater the number of abalone that can be packed therein and the more efficient the breeding process. Of course, within reasonable limits, it is therefore generally desirable to maximize the amount of surface area inside the pen.

In some implementations, the pen can be configured to receive therein means providing a further inner surface for receiving abalone. The member may have any suitable form, so long as abalone can rest on the member, the member can fit within the pen, and the member does not adversely obstruct the flow of water and food through the pen. As will be appreciated, the member is also desirably removable from the pen in order to more easily harvest any abalone thereon.

The fence may be capable of receiving the member in any suitable manner. For example, the rail can include a recess adapted to retain one or more rails therebetween with the members depending from the rails. Alternatively, the fence may include appropriately aligned slots or channels into which the edges of the members are received. Ideally, the members hang in the interior of the pen, leaving as much surface area as possible for the abalone on the inner wall of the container.

The member itself may have any suitable form as long as it is capable of satisfying the functional requirements described above. In some embodiments, for example, the members may be substantially planar, which makes the abalone easier to remove (i.e. after removing the members from the pen) and easier to store when not in use. In some embodiments, for example, the members may be foldable to fit within the pen, and in some embodiments may be foldable many times to define many additional surfaces for receiving abalone. The member may be, for example, foldable such that the further surfaces are substantially parallel to each other and separated by the abalone receiving distance. As will be appreciated, abalone tends to prefer the corners and corners that such folds will form.

In some embodiments, multiple members can be present inside the rail (e.g., running along the length and/or width of the elongate rail, and optionally joined to one another so as to provide a virtually continuous surface). In some embodiments, fasteners may be provided to releasably attach multiple members together.

In particular embodiments, the member may be provided in the form of corrugated plastic or corrugated board (e.g., planar honeycomb board material). For example, a 1.2m x 1.2m honeycomb panel (e.g. formed of polypropylene and having a thickness of about 4 mm) may be folded (e.g. at fold lines that may be formed using thermal techniques known in the art) to create an inner surface area for abalone to attach to and feed. The sheet may include 50mm holes for abalone to traverse the surface and search for food, and may include 18mm holes through which support bars may be received, the support bars being placed into receiving lugs in opposite sides of the container wall embedded in the pen. Such honeycomb panel members are advantageous because they are lightweight and durable.

The submersible container also includes one or more feeding ports in the container wall through which feed for abalone can be dispensed into the pen. In some embodiments, the feeding port may be defined by an aperture through the container wall, wherein the aperture is configured to receive a respective feed dispenser therein (e.g., using threads, etc.).

The submersible container also includes one or more feed dispensers. Each feed dispenser comprises a reservoir for abalone feed and a mouth portion configured for receipt at a respective feeding port and is independently operable to dispense feed contained in its reservoir into the pen.

The delivery of feed to abalone inside the container of the invention requires careful monitoring-insufficient feed will not grow at an optimal rate, but too much feed may result in adversely affecting water quality and increasing production costs. Although it is possible to closely monitor the growth of abalone in an onshore facility, offshore monitoring is much more complex. Feeding of abalone should normally be done weekly, but in an offshore facility a lot of time and effort would be required to perform this feeding (compared to an onshore facility). Indeed, some containers suggested for use in offshore abalone farms require the use of divers or remotely controlled submersible vehicles in order to feed the abalone contained therein. Use of the feed dispenser described herein will significantly reduce the effort and expense associated with feeding abalone in an offshore facility.

Any suitable mechanism may be used to cause each feed dispenser to dispense the feed contained therein. The feed dispenser may, for example, be operable (or adapted) to dispense feed contained therein into the pen at a predetermined time or in response to a signal (generated internally or externally of the dispenser). In embodiments where multiple feed dispensers are used, each of the feed dispensers may be operable (or adapted) to dispense its feed into the pen at different times. Such feed dispensers may thus be used in combination to reduce the frequency with which containers must be retrieved from the sea to inspect and/or feed abalone without having to employ expensive resources such as divers.

Any suitable method can be used to dispense the feed contained in the reservoir into the pen. In some embodiments, for example, each of the dispensers can include a gate that is movable from a closed position to an open position upon receiving the signal, whereby feed contained in the reservoir is dispensed into the pen when the gate is moved into the open position. The gate may be, for example, spring loaded, as described in more detail below.

In particular embodiments, a feed dispenser for use with the submersible container of the present invention may comprise: a reservoir configured to hold abalone food; a coupling configured to be received in a respective feeding port of a container; and a gate movable from a closed position into an open position upon receiving the signal. When the gate is moved into the open position, feed contained in the reservoir is dispensed.

The invention also provides a feed dispenser suitable for use with the submersible container of the invention described above, but which can be readily adapted for use with other containers containing abalone, or indeed other aquatic species. The feed dispenser comprises: a reservoir configured to hold feed for abalone; a mouth portion configured to be received in a feeding port of a container; and a gate movable from a closed position into an open position upon receiving the signal. When the gate is moved into the open position, feed contained in the reservoir is dispensed.

As will be appreciated, the use of such a feeder to automatically dispense feed to abalone will reduce the frequency with which abalone needs to be removed from the water for feeding. Indeed, with a plurality of feeders of the invention it will be possible to persist for a long period of time without having to inspect abalone, but in practice this should not exceed about a month, as at least inventory should be checked at this frequency to ensure that abalone is growing at an appropriate rate, that no predators are present, that the flow of seawater through the container is not impeded by dirt, etc.

The signal for each feeder to dispense its feed into the pen of the container may be generated internally (e.g. at the end of a predetermined time) or externally (e.g. in response to a radio or microwave signal sent from the base).

In certain embodiments, for example, there may be three feeders on the submersible container that are programmed to dispense their feed after 7 days, 14 days, and 21 days, respectively. Thus, once the operator on the boat has inspected the abalone in the container to ensure that they are growing properly etc., enough food can be added for 7 days, the container closed and then returned to the sea. Now the operator will not have to retrieve this container for inspection etc. within 28 days.

In some embodiments, the feeder may also be adapted to provide a warning signal, for example in the event that the feeder fails to discharge its feed or is otherwise damaged.

Submersible vessels may also include additional features or components consistent with their intended use. In some embodiments, for example, the container may further comprise one or more attachment points (e.g. apertures adapted to receive a connector or tether therethrough) from which the container may be suspended or lifted into or out of the water for periodic inspection and feeding of abalone and inspection and maintenance of the container. Typically, each container will have at least two attachment points, typically located at the distal end of the container for maximum stability when suspended into the water or when lifted/lowered.

Submersible vessels may also include features or components for measuring relevant parameters such as flux of seawater through the pen, temperature, pH, salinity of the seawater, concentration of substances in the water inside the vessel (such as heavy metals, etc.). These parameters may be useful to optimise the growth of abalone or may provide an immediate warning in the event that conditions become unsuitable for abalone. The container may also include a waterproof camera capable of transmitting a visual image of the interior of the container to a remote operator. In some embodiments, it may be necessary for the vessel (or another component of the offshore facility, such as a buoy attached to a long rope, as described below) to include a radio transmitter in order to transmit these images to the remote operator. The camera and/or radio transmitter may be powered by solar energy where appropriate. These instruments may be associated with the containers in any suitable manner, such as by inserting them into one of the feeding ports in the containers (described below).

Method for growing abalone in an offshore location

The invention also provides a method for growing abalone in an offshore location. The method comprises deploying one or more of the submersible vessels of the invention as described above on a long rope anchored to the sea floor, and periodically retrieving each of the one or more submersible vessels and inspecting the abalone contained therein (e.g. for predators, expected growth, any mortality, etc.). The method will typically also include replacing any empty feed dispensers with full feed dispensers.

As will be described in more detail below, in some embodiments, one or more submersible vessels may be retrieved using a retrieval device suspended on the side of the boat. The retrieval apparatus is operable to lift the container from the water, position the container on the deck of the boat for inspection of the abalone contained therein, and then place the container back into the water.

In some embodiments, the long line consists of a rope (trunk) of between about 10 and 500 meters in length (e.g., between about 50 and 200 meters in length, or about 100 meters in length) suspended from a buoy spaced along it (e.g., at a spacing of between about 1 and 100 meters, between about 5 and 50 meters, or about 10 meters) and secured at its distal end to the seafloor by a helical anchor, concrete block, or the like. Approximately 20 containers of the invention may be suspended from a long rope of 100m (e.g. between about 1m and 3m below the water surface) which will result in the production of approximately 2 tonnes of abalone per year. The size of the offshore facility may for example be about 3 hectares and contain about 10 long ropes. Work boats come and go to the facility every day, which is usually very close to the hatchery. Approximately 20 tons of abalone are expected to be produced annually per 3 hectares of site.

In some embodiments, the method may comprise a first offshore rearing stage (intermediate growth stage) in which abalone removed from an onshore plate-like water tank of size about 25mm (after an onshore duration of about 12 months) is placed in the above-described container and immersed in water. Each suitably sized container may contain up to about 4,000 abalone of this size. Abalone is periodically fed and inspected, for example as described above, for approximately 12 months, during which time abalone grows to a size of approximately 50 mm.

At the end of the first offshore rearing stage, the container is removed from the water and shipped to a processing facility where the abalone is removed from the container, sorted, inspected (for health and weight, and any undersized or too small animals are discarded). The appropriate number (approximately 2,000 abalone 50 mm) is then put back into another container for a second offshore rearing stage (the growing stage). The used container is inspected for any predator intrusion and cleaned, ready for re-use. The vessel is then used to return the container containing abalone to the offshore facility for a second offshore rearing stage in which the abalones grow to a size of about 80-90mm in a further 12 months when they are ready to be harvested for launch.

Recovery occurs at the end of the growth phase (i.e., approximately after another 12 months offshore). The amount of food that abalone is fed during this stage increases and grows 25mm but gains 80% of its final weight. The container is again removed from the long rope and shipped to a processing facility where the abalone is removed from the container and sorted by size. They are subsequently processed into one of many different types of market products, including fresh, frozen, canned, IQF (split flash frozen) or dried. The vessel is then cleaned for reuse in the first or second offshore rearing stage.

As mentioned above, the abalone inside the container is periodically checked during the intermediate and growing phases to ensure that they are growing at the expected rate and that no bad things happen on them. Typically the containers must be removed from the water in their entirety approximately every month in order to refill the feed dispenser, during which time visual inspection of the abalone in each container (either through the feeding port or by opening the container) can be performed. However, during this period it is good practice to monitor the abalone continuously, and this can be achieved by performing periodic inspections of the abalone in random containers (on each long rope every few days or every week). During such inspection, individual containers on a long rope may be retrieved and inspected for their contents (e.g., through an aperture, by removing the feed dispenser and looking into the interior of the container through a feeding port, or by opening the container). If the abalone in the inspected container is growing as expected, it can reasonably be inferred that the same is true for abalone in the surrounding containers. Thus, a periodic inspection process can be performed, but effort is expended to be a small fraction of a full inspection.

The vessel may advantageously be deployed from and retrieved by a maintenance boat or ship without the need for divers. More advantageously, the long ropes allow the vessel to drift as the tide rises and falls, thereby minimising the effect of shadows cast in the seabed and improving the "environmentally friendly" nature of the installation. Furthermore, when the vessel is suspended below the sea surface, the water flow therethrough can be maximized, thereby providing more nutrition and oxygenation than in a farm located in a fixed location.

In some embodiments, one or more submersible vessels may be retrieved using a retrieval device suspended on the side of the boat or ship, the retrieval device being operable to lift the vessel from the water, position the vessel on the deck of the boat for inspection of abalone contained therein, and then place the vessel back into the water.

The retrieval apparatus may also be able to engage and lift the long rope from the water to a convenient height so that the container attached to the long rope is accessible to a person on the boat, preferably without having to remove the container from the long rope. The retrieval device may also be operable to position the container on the deck of the boat where the abalone can be inspected in a highly convenient manner (e.g. by opening the container when it rests on the deck and is not hanging down from the side of the boat).

The retrieval device may have any structure suitable for implementing the functionality discussed above. A particular form of retrieval device is described below by way of example only.

Specific embodiments of the present invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings.

Referring initially to FIG. 1, a tank system 10 is shown according to an embodiment of the present invention. The tank system 10 has eight prefabricated base sections 12, the eight prefabricated base sections 12 being arranged in an array of two base sections wide and four base sections long. The central slot 14 divides the array of base portions in half. Each base portion 12 is about 5m wide and about 9m long so that when combined as shown, eight channels (shown generally at 16) are provided, each having a width of about 2.5m and a length of about 18 m. The bottom of each base portion 12 is approximately 150mm thick, which provides a suitable balance of strength and weight.

Each base portion 12 has three upstanding walls (shown generally at 18) extending the length of the base portion 12 and aligned with corresponding walls on adjacent base portions to define a channel 16 therebetween. The wall 18 is about 150mm high, which readily enables a water depth of about 70mm (see figure 2) to be maintained in the channel 16 for abalone to move around, feed and grow. In some embodiments (not shown), the upper portion of the wall 18 may be provided with a track along which an automated feeder may travel. The structure of the wall 18 will be described in more detail below.

Each prefabricated base section 12 is precast from concrete and will weigh around 10 tonnes or so that it can be transported and assembled using conventional equipment. Although not shown, the surface of the base portion 12 on which the abalone will rest may comprise ridges or the like which provide shelter for the abalone. The ridges are preferably created during the manufacturing process and may be arranged in the channels in a transverse orientation or in other orientations (such as a longitudinal orientation) to, for example, assist the flow of water along the channels 16. The upper portion of the wall 18 may also include a coating (not shown) to help prevent abalone from escaping.

In an alternative embodiment (see fig. 6), the base portion 112 may be provided with a width of about 10m and a length of 9m, which means that an 8-channel cistern system 110 similar to the cistern system 10 would only require four base portions 112. While it may be advantageous to use fewer base portions to manufacture the tank system, these advantages must be carefully evaluated in light of the difficulty involved in transporting and installing larger (and thus potentially heavier) components.

It will be apparent to those skilled in the art that the tank system 10 (and 110) can provide not only construction efficiency compared to existing plate-like tank construction methods (i.e., concrete placement), but also operational and ongoing maintenance efficiency of the tank system 10 in the abalone farming industry (as will be described below). The water tank system 10 provides an environment for growing young abalones from a flat water tank to a size of about 25mm, after which they may be harvested and placed, for example, in an offshore facility for further growth. Alternatively, if no offshore facilities are available, the young abalone may grow in the tank system 10 to marketable sizes.

Although not shown, the prefabricated base portion 12 (and 112) may include other components of the cistern system 10 (and 110), such as, for example, plumbing components, electrical components, or components that facilitate attaching other parts of the cistern system to the base portion. Such components may be pre-fabricated within the pre-fabricated base portion during manufacture of the pre-fabricated base portion.

The

prefabricated base parts

12, 12 are joined end to end at a joint 20, the joint 20 being shown in exaggerated form in fig. 1. The engagement point 20 has an extended-retracted arrangement in which a projection 22 on one edge of the base portion 12 is received on a lip 24 on the edge of the adjacent base portion 12. The degree of overlap of the joints 20 is typically about 50mm and the pressure on the joints 20 is typically sufficient to make them water-tight (although in some cases the joints 20 may also be provided with seals, not shown in the figures). Joining laterally adjacent

prefabricated base portions

12, 12 may not necessarily require a joint such as joint 20, as a watertight joint between these portions would not be necessary (due to walls 18, 18). The

adjacent base portions

12, 12 may be connected using any suitable means, such as clips or other fasteners (not shown), or may remain in their respective positions due to their weight.

The distal end of each base portion 12 has no walls, but is open ended and is thus capable of engaging the

end slots

26, 26 and the central slot 14 in a manner described below. As will also be described in greater detail below, the

end tanks

26, 26 and the central tank 14 provide a supply of water to the channels 16 and a drain for the water. In use, water may be arranged to flow through the channel 16 in one direction for one predetermined period of time and then in the opposite direction for another predetermined period of time. This flow of water mimics the tide and helps to feed and oxygenate the abalone evenly and to clean the channels 16.

Referring now to fig. 2 and 3, the end slots 26 and surrounding parts of the

sections

12, 12 are shown in more detail. The end tank 26 is adapted to supply water to the tank system 10 and to drain water from the tank system 10. The end grooves 26 are adapted to sealingly engage the edges of the preformed

base portions

12, 12 so that it is in fluid communication with all four channels 16. The slot 26 has a first longitudinal wall 28 and a second longitudinal wall 30. The first wall 28 is adapted to engage the lower side edge of the bases 12, 12 (i.e., as shown in FIG. 2) and is lower than the second wall 30 (i.e., when the end slot is in its operative configuration). These height differences enable the trough 26 to be in fluid communication with the channel 16 and retain water in the channel 16, but water cannot escape past the wall 30 (as can be seen in fig. 2). The end tank 26 also includes a divider 32 (see fig. 3), which divider 32 is aligned with the wall 18 so as to properly position the

pre-made base portions

12, 12 relative to the end tank 26 (as will be described in more detail below) and substantially prevent water from flowing from one channel 16 to the other channel 16 (which may lead to cross-contamination of the channels 16, 16). The end tank 26 also includes raised

portions

34, 34 at its distal edges, which raised

portions

34, 34 align with the

walls

18, 18 at the corresponding edges of the

base portions

12, 12 to prevent water from escaping the system 10.

As can be seen in fig. 3, the central divider 32 of the slot 26 extends above and over the wall 28 and has a width receivable within the gap between the

walls

18, 18 of

adjacent base portions

12, 12. As discussed above, this arrangement can help ensure proper (watertight) alignment of the

base portions

12, 12 and end tank 26 and each other. When the central partition 32 of the slot 26 is received within the gap between the walls 18, and the

other walls

18, 18 of each

base portion

12, 12 abut and align with the

partitions

32, 32 and the raised ends 34, respectively, the

base portions

12, 12 and the end slots 26 are properly aligned with one another.

The central divider 32 of the slot 26 and the gap between the

walls

18, 18 of adjacent base portions may also provide another advantage. As will be appreciated, it would be a relatively simple way for an operator to visually inspect the four outermost channels 16 of the waterbox system 10. However, the innermost four channels 16 are not easily inspected, as they are more than 2.5m from the edge of the system 10. It may be useful to provide a walkway (not shown) along the center of the cistern system 10 so that an operator can walk between the innermost four channels 16. In this regard, because the walls 18 and

dividers

32, 34 are all about 150mm wide, the overall width of the central wall (i.e., the

walls

18, 18 that comprise the left and

right base portions

12, 12 with the divider 32 interposed therebetween) will be about 450mm wide-i.e., wide enough to walk over. Alternatively, a walkway (not shown) may be provided over the central portion of the system 10, with ribs on the underside of the walkway adapted to be received between the

walls

18, 18 of the left and

right base portions

12, 12 and thereby support the walkway.

One or more pipes 36 (see fig. 2) are provided to convey the flow of seawater into the end tanks 26. If there is only one pipe, the divider 32 must not extend all the way to the bottom of the trough 26, so that water flows under the divider 32 and then into each channel 16. Alternatively, a pipe 36 may be provided for each channel 16 (but this would involve more infrastructure). As water flows from the

end tanks

26, 26 into the channels 16, the volume of seawater flowing from the one or more pipes 36 is controlled to provide the proper flow rate through the channels (and maintain the proper water level in the channels).

The end tank 26 also includes one or more drain ports 37, the one or more drain ports 37 being openable to drain a selectable volume of seawater from the tank. When the flow of water is reversed and water flows from the

channels

16, 16 into the end tanks 26, the volume of seawater discharged through the

discharge ports

37, 37 is controlled to provide the proper flow rate through the channels (and maintain the proper water level in the channels).

The

walls

28, 30 and base of the end tank 26 may have a thickness of about 150mm and, like the prefabricated base portion 12, may be precast concrete. The system 10 may also include a barrier or grating (not shown) to prevent abalone from entering the end tanks 26 (and central tank 14).

Referring now to fig. 4 and 5, the central slot 14 is shown in greater detail. As with the end tanks 26, the central tank 14 spans the entire width of the array of

adjacent bases

12, 12 and is adapted to supply water to the tank system 10 and drain water from the tank system 10. Each

edge wall

38, 38 of the central groove 14 may receive and sealingly engage the underside of the edge of the aligned preformed

base portions

12, 12 so that the central groove 14 is in fluid communication with all of the channels 16 in the system 10.

Similar to the end slots 26, the central slot 14 also has dividers (shown generally at 39 and 40) that are aligned with the walls 18 and abut or receive the walls 18 therein and generally prevent water from flowing from one channel 16 to the other channel 16, as described above. As can be seen in fig. 4, the central partition 40 is adapted to be received in a recess located between the

walls

18, 18 of

adjacent base portions

12, 12 so as to ensure proper alignment of the

base portions

12, 12 at both ends (i.e., in conjunction with the

central partitions

32, 32 of the end slots 26, 26). Once so aligned, a substantially fluid-tight seal is formed between the central groove 14 and the channel 16.

In fig. 5, the central trough 14 is shown with a water supply in the form of

water inlets

41, 41 and a water drain in the form of a water drain 42. The inlet 41 and the drain 42 are selectively operable (in combination with equivalent features in the end tanks 26, 26) to achieve a desired direction of water flow through the channel 16.

Fig. 5 also (partially) shows a wave generator 44 that includes a rotating cylinder 46 operable to generate water waves that may help clean the channel 16 by removing any debris and waste that may have accumulated in the channel 16. Periodic flushing of the channel 16 will help maintain good health of the abalone and may help improve muscle mass. The wave generators 44 are located on a platform 48 positioned above the central trough 14 so that waves can be caused to flow in either a leftward or rightward direction (see fig. 5) and thus flush the channels 16 on either side of the central trough 14. Alternatively (and as shown, for example, in fig. 6), the wave generator 44 may instead (or additionally) be located above one or both of the end troughs 26, wherein waves will pass through the channel 16 and into the central trough 14.

The wave generator 44 comprises means for filling the rotating cylinder 46 with sea water, such as a tap, a hose or the like (not shown). The rotating cylinder 46 is rotatable and includes large apertures for quick release of water therefrom (not shown). In this manner, an operator may fill cylinder 46 and then rapidly rotate cylinder 46 to release water into the desired channel 16. This operation may also be performed automatically if appropriate infrastructure is provided. The cylinder 46 may be rotated in either direction to enable waves to be generated in either direction. In another embodiment, the cylinder 46 may be disposed in an unstable configuration such that filling the cylinder 46 (e.g., by a continuous supply of water) causes the cylinder 46 to topple from time to time (once a particular volume of water is contained therein), thereby creating periodic waves.

The wave generator 44 may also include wheels 50, which wheels 50 may rest on rails 51 provided on the platform 48 so as to be slidable between adjacent channels 16. In this manner, an operator may use cylinder 46 to flush first channel 16, and then push cylinder 46 along track 50 until cylinder 46 is positioned over second channel 16, and repeat the process.

In an alternative embodiment (not shown), the wave generator may comprise at least one sprayer for spraying water. In this alternative embodiment, the wave generator relies on a movable nozzle to generate waves. In particular, the wave generator comprises a nozzle mounted on a gantry or the like, wherein the gantry is movable up and down along the length of one or more channels 16. In use, an operator will position the gantry at one end of the tunnel 16, activate the nebulizer, and then move the gantry along the length of the tunnel 16. The sprayers may be oriented in the direction of movement to enable waves to be generated. Further, the orientation of the sprayer may be user configurable so that an operator may orient the sprayer in an opposite orientation for a return stroke along the channel 16. Also in this embodiment, the gantry may be located on a track (not shown), such as a track located above the wall 18.

An alternative embodiment of a water tank system in the form of a water tank system 110 is shown in fig. 6. The tank system 110 has four prefabricated base sections 112, the four prefabricated base sections 112 being arranged in an array that is one base section 112 wide and four base sections 112 long. The central slot 114 divides the array of base portions in half. Each base portion 112 is about 10m wide and about 9m long such that when combined as shown, four channels (shown generally at 116) having a width of about 2.5m are provided in each half (i.e., the system 100 has eight channels 116 in total). The water tank system 110 also includes three wave generators 144 positioned above the central trough 114 and the

end troughs

126, 126.

The prefabricated base portion 112 of the tank system 110 is not placed directly on the ground, but is placed in an elevated position. This arrangement is advantageous because space is provided for the central slot 114 and end slots 126, and no foundation needs to be prepared. In one embodiment, posts (such as helical posts shown generally at 160) are used to provide the proposed height. In this manner, during construction, the screw struts 160 are screwed into the ground to the desired height, after which the prefabricated base parts 112 are placed (separately or together) on top of the screw struts 160. The helical struts 160 also provide support for the central and end grooves 114, 126 relative to which the preformed base portion 112 is positioned in the manner described above. The relative height of each spiral strut 160 may be adjusted by screwing the strut 160 into or out of the ground to provide substantially uniform support for the entire tank system 110.

Referring now to fig. 7, a water supply and drain system 200 is shown for supplying water flow to eight channels (shown generally as 216) in a water tank system 210. The supply system 200 has a main supply line 270. The main supply line 270 typically draws water directly from the sea. The supply system 200 also includes a secondary backup line 280 for use in situations where the main supply line 270 fails for whatever reason or provides insufficient water flow. The main supply line 270 and the secondary backup line 280 are capable of supplying water to the end water supply and drain

troughs

226, 226 and the central water supply and drain trough 214.

The drain system 200 includes a drain outlet (shown generally at 290) that is selectively operable by a control valve (shown generally at 292). The drain outlet 290 feeds into a drain spur 294, which drain spur 294 may include one or more manholes for ingress and egress (not shown). The discharge spur 294 is fed into one or more settling ponds (also not shown) where water can be stored (if necessary for disposal) before being returned to the sea.

Referring now to FIG. 8, an exemplary array of tank systems 10 (or 110 or 210) is shown. The array of tanks includes six tank systems (shown generally at 10) that may be housed in the shed 60. The shed 60 may, for example, provide a dark environment that is liked by abalone. The shed 60 includes a work and storage area 62 that may be accessed through one or more doors 64. A water supply and drain system (similar to that described above with reference to fig. 7) may be used to supply water to all of the tank systems 10 inside the shed 60.

Referring now to figures 9 to 12, there is shown a submersible container for storing abalone, in the form of a tube 300 in figure 9 and a tube 301 in figures 10 to 12. The

tubes

300 and 301 are identical except for the number of feeding ports they have, with tube 300 having three feeding ports and tube 301 having only one feeding port. The same reference numerals will be used hereinafter to describe common features of the

tubes

300 and 301.

In this embodiment, the

tubes

300 and 301 are tubular in shape, having an inner diameter of about 570mm and a length of about 2200 mm. However, the shape of the tube 300/301 may be configured according to its intended application and may be spherical or similar, or the cross-section may be non-circular (e.g., oval, triangular, square, etc.). The tubular shape advantageously provides ease of treatment while allowing water to pass through the tube 300/301, wherein the tube is generally aligned with tidal and/or ocean currents in use to maximize water flow therethrough. The tube 300/301 may be made of a suitable plastics material, such as polyethylene, and preferably food grade polyethylene, so as not to risk contamination of abalone for human consumption. The tube 300/301 is preferably black (at least on the inside) because abalone prefers a dark environment. However, the highly visible coloration on the outside of the tube 300/301 makes it more visually distinct and therefore easier to locate when in water.

The tube 300/301 includes two halves: an upper half 302 and a lower half 304. The upper and

lower halves

302, 304 are joined along one edge by a hinge (shown generally as hinge 306). The hinge 306 may be an integral hinge with a PVC or PE hinge rod. As can be seen by comparing fig. 9 with fig. 10, tube 300/301 is fully openable for access to the interior thereof for cleaning, maintenance and abalone recovery. The upper and

lower halves

302, 304 are substantially identical to one another, thereby enabling the tube 300/301 to be made from the same plastic injection or rotational mold (the tube does not include an extension, thereby allowing it to be made from a single plastic injection or rotational mold). As can be seen in fig. 10, the empty tubes 300/301 may be stacked together for storage when in the open configuration.

Tube 300/301 also includes a releasable mechanical interlock, shown generally in the form of latch 308 (see fig. 10), that allows tube 300/301 to be locked in its closed configuration. Each latch 308 includes a male prong 310 on the edge of the lower half 304 that is adapted to be received within a corresponding recess 312 on the edge of the upper half 302 (or vice versa). The tongues on the prongs 310 are retained by corresponding grooves in the recesses 312 so that once in their closed configuration, a simultaneous pushing and opening action is required (highly unlikely to be performed inadvertently, especially if there are many latches 308 to open) to open the tube 300/301. As can be seen in fig. 10, the latch 308 is recessed to avoid damage in use and to reduce the likelihood of being opened inadvertently, whether in the sea or when being loaded/unloaded.

The walls of tube 300/301 have a two-layer construction with an outer layer (best seen in fig. 9) and an inner layer (best seen in fig. 10) that define a cavity therebetween. This cavity may be filled with water, air, sand, or a combination thereof to adjust the buoyancy of tube 300/301, and apertures with plugs 314 are provided in upper half 302 and lower half 304 to facilitate such operation. Both the inner and outer layers also include a plurality of dimples (shown generally at 315) that abut one another within the cavity to increase the structural rigidity of the wall. The dimples 315 may be generally conical, which may help to further increase strength.

Tube 300/301 also has two lifting lugs (shown generally at 316) at each end of each

half

302, 304. The lifting lugs 316 are integrally formed with the tube wall and include apertures into which a rope or other attachment device may be received in order to suspend the tube 300/301 in the water and/or retrieve and deploy the tube (as described below). As can be seen in fig. 9 and 10, the lifting lugs 316, 316 are also configured such that each half of the tube 300 forms at least two (and preferably three, as shown in the figures) contact points with the ground to prevent the round tube 300/301 from rolling when resting on a surface (e.g., the deck of a boat).

Although the tube 300/301 may be located on the sea floor when the abalone contained therein is grown, it is generally preferred to hang it in the water column (i.e. in this case it is more accessible for inspection, more likely to be exposed to tidal and ocean currents, less susceptible to predators and biofouling, etc.). The upper half 302 of the tube 300/301 thus also has an aperture (shown generally at 318) at each end for receiving a tether (not shown) by which the tube may be suspended, for example from a long rope, into the sea (described below). A tether may be placed through aperture 318 and tied using a safety knot, such as a water hand knot, to secure tube 300/301 to the tether. In this manner, the tether is able to freely pass through the aperture, thereby allowing the tube 300/301 to float up and down in the ocean current. The aperture 318 is oriented upwardly in use to engage a tether. Corresponding apertures (shown generally at 319) may also be provided on the lower half 304, for example, to which weights may be attached.

As can be seen in fig. 10, the inner surfaces of the upper half 302 and the lower half 304 include a number of longitudinally extending ribs (shown generally at 320). Ribs 320 promote perching of abalone by allowing food to collect and provide an obstacle against which abalone can rest. The ribs 320 may also help increase the structural rigidity of the tube 300/301.

The tube 300/301 also includes a number of apertures configured to allow water to flow through the interior thereof. Tube 300/301 includes

end apertures

322 and 324 and a number of side apertures (shown generally at 326). Because

apertures

322, 324 and 326 are very large, to prevent abalone from escaping,

apertures

322, 324 and 326 are covered with a mesh (shown generally as mesh 328) (in fig. 9, mesh 328 covers end aperture 322). The mesh 328 allows water to pass therethrough in use, but is too thin to allow abalone to pass through. The mesh 328 is formed of corrosion resistant stainless steel and has a thickness and pore size such that the abalone is self-cleaning by ingestion (in the manner described above). The screen 328 is provided in the form of a disc having a rubber ring (not numbered) on its periphery. The rubber rings are adapted to be received in

recesses

330, 330 located at opposite ends of the upper and lower halves 302, 304 (see fig. 10 and 12). Each depression 330 is located a small distance inward of the interior of tube 300/301 to protect screen 328 from impact and damage. Once the tube 300/301 is closed, the mesh 328 is securely retained within the recesses 330 at each end of the tube 300/301 and defines a pen for abalone therebetween.

The upper half 302 of the tube 300 also includes three feeding ports (shown at 332, and 332), each of which is adapted to receive a feed dispenser (described below) therein. The feeding

ports

332, 332 and 332 are evenly spaced along the length of the tube 300. Similarly, the upper half 302 of the tube 301 includes a centrally located feeding port (shown at 332). Each feeding port 332 has threads (not shown) into which a feed dispenser may be screwed and through which the feed dispenser extends to the interior of the tube, as will be described in more detail below. When it is not fitted with a feed dispenser, feeding port 332 may be covered with a removable plug, such as a round plug or a screw-type plug (not shown).

Referring now to figures 11 and 12, it is shown that the tube 300/301 contains means for increasing the available surface area for abalone inside the tube, said means being in the form of a folded honeycomb panel 334. As described above, increasing the available surface area inside tube 300/301 will increase the abalone carrying capacity of the tube. The sheet 334 is folded into an accordion configuration and is located within the tube 300/301 and is held in place by at least one (typically three for this length of tube) internal cross bar 336. As can be seen, the webs 334 overhang the tube 300/301 and therefore do not adversely affect the abalone carrying capacity of the inner wall of the tube. Crossbar 336 engages the interior of the tube in a manner described below. Depending on the size of the sheets 334 and the length of the tube 300/301, more than one sheet 334 may be provided to maximize the available surface area inside the tube.

In this way, the maximum surface area is provided within tube 300/301 so that the maximum possible number of abalone can be stored therein. Furthermore, the concertina-like shape of the member provides a number of corners and crevices in which abalone can hide and where food can collect, thereby providing an ideal growing environment for abalone. Advantageously, however, because the lamella 334 is provided in the form of a single member that is substantially planar when deployed, it is easily removed (i.e. intact) from the tube and once deployed it is very easy to remove abalone therefrom (no corners or the like available for abalone to hide). The orientation of the webs 334 (generally parallel to the longitudinal axis of the tubes 300/301) is such that a sufficient volume of oxygenated seawater flows through the tubes.

Fig. 13 shows an alternative embodiment of a sheet 334, in an expanded configuration and in the form of a sheet 337. Sheet 337 has a similar construction and form (when folded) to that of sheet 334 and is otherwise identical to sheet 334 except for the slightly different arrangement of apertures therein (described below). The sheet 337 has a number of pre-folded lines (shown generally at 338) to enable it to be readily folded into the configuration shown in fig. 11 and 12. The pre-break line 338 may be applied to the sheet 337 (and to the sheet 334) during construction, or may be added in the field using any suitable thermal or ultrasonic based technique. The sheets 337 (and 334) include relatively thinner connecting strips (generally shown as 340) interposed between relatively wider flat plate portions (generally shown as 342). The connecting strip 340 has a width sufficient to provide a distance between adjacent plate portions 342, 342 (i.e. when folded) whereby the abalone is free to move around unimpeded.

The sheet 337 also has an array of relatively large apertures (shown generally at 344) that allow abalone, food, oxygenated water, etc. to pass therethrough. In the illustrated embodiment, the large apertures 344 are arranged such that each flat plate portion 342 includes two apertures 344 and each connecting bar 340 includes three apertures 344. The smaller apertures, generally shown as 346, are sized and positioned to receive the cross bar 336 therethrough when the sheets 337 (or 334) are in the folded configuration so that the folded sheets may fit within the interior of the tube 300/301, as described above (see fig. 12).

The sheet 337 also has one or more fasteners 348 (only one fastener is shown in fig. 13 for clarity) for fastening adjacent

flat plate portions

342, 342 to each other and thus maintaining the sheet 337 (or 334) in the concertina-type arrangement shown in fig. 11 and 12 despite other forces that may be pressed against the folded sheet in use. The plate fastener 348 includes a releasable mechanical interlock such that the

plate portions

342, 342 are releasably fastened together by the slot and tab arrangement. In this regard, the panel fastener 348 has a tab 350, which tab 350 is inwardly foldable so that the fastener 348 is insertable into a corresponding slot (shown generally as slot 352) in the adjacent panel 342. Once through the slot 352, the tabs 350 will tend to elastically spread apart, making the fastener 348 too large to pass back through the slot 352. Preferably, the flat panel fastener 348 is press-cut so as to be integral with the portion 342, wherein the fastener 348 is foldable in use for insertion into the slot 352. Alternatively, the panel fasteners 348 may be adhered to the surface of the adjacent panel portion 342, but this arrangement may cause damage to the panels and/or fasteners when the sheet 334 is removed from the tube 300/301 and unfolded for easier access to the abalone thereon.

As best shown in fig. 11, the sheet 334/337 is foldable to define an outer profile having a shape adapted to fit within the circular interior of the tube 300/301 in use. Thus, the width of the flat panel 342 may vary, becoming narrower toward the edge of the sheet 334/337.

As described above, the

sheets

334 and 337 are made of a lightweight and durable honeycomb panel material. The preferred direction of the grooves is shown by cut 354 (see fig. 13). This orientation advantageously allows for extended stiffness of the sheet 334/337 and allows any trapped air to escape when immersed in water. The honeycomb panel material may be made of food grade material and may be black in colour, as abalone likes the dark environment.

At the end of the abalone growth cycle, the folded sheet 334/337 may be removed from the interior of the tube 300/301 (i.e. once removed from the water and unfolded) and unfolded so as to provide a substantially planar surface. As will be appreciated, it is much easier to remove abalone from a planar surface than from a folded surface.

As will be described in more detail below, pipe 300/301 is suitable for use in a submerged configuration in an offshore abalone farm. Three thousand or more young abalones, approximately 25mm in length, are introduced into the tube and fed regularly (approximately every 1-2 weeks, e.g. as described below) with a suitable prepared food. After about 1 year the abalone will grow to a length of about 50mm and is then ready to be removed from the tube, sized and approximately 1800 abalones of length about 50mm are loaded back into the tube (not necessarily the same tube). The newly loaded pipe will then be submerged again in the water in the offshore farm for approximately another 12 months. After this time, the tube was opened and mature abalone approximately 90mm in diameter was removed and made ready for market.

Referring now to fig. 14-18, a feed dispenser for use with tube 300/301 (for example) is shown in the form of dispenser 400. The dispenser 400 has threads 402 and a cap 404 for coupling (in a manner described below) with the feeding ports 332 of the

tubes

300 and 301. As can be seen by comparing fig. 14 and 15, the lid 404 is operable to move between a closed position (fig. 14) and an open position (fig. 15). Once the lid 404 is opened, the interior 406 of the dispenser 400 is accessible, as will be described in more detail below. The lid 404 is coupled to the dispenser 400 along a hinge 408 and is normally biased toward an open position so that it snaps open and moves to the position shown in fig. 15 upon release. The lid 404 has a number of projections (shown generally as 410) configured to be received in complementary recesses (shown generally as 412) in the dispenser 400. A lip visible on the projection 410 interacts with a complementary protrusion (not shown) within the recess 412 to hold the lid 404 closed until the protrusion is moved, after which the lid 404 pops open.

The length of time that lid 404 remains closed may be predetermined, for example, by a user immediately before they couple a full dispenser 400 with feeding port 332 of tube 300/301. Alternatively, the length of time that the lid 404 remains closed may be controlled externally. In the embodiment shown, for example, the dispenser 400 includes a timer (not shown) and a rotatable sleeve 414 that is rotatable relative to the rest of the body of the dispenser in order to adjust the length of time before the cap 404 will open. Indicia (shown generally at 416) may be included to allow the operator to accurately set the desired time period. The indicia may, for example, indicate the number of hours, days, or weeks before the timer will cause the lid 404 to open. Typically, the indicia will indicate a period of 1 week, 2 weeks, 3 weeks, or 4 weeks, but even up to 5 weeks.

Referring now to fig. 16, the opposite end of the dispenser 400 is shown, including a recessed portion (not numbered) and a handle 418 to facilitate handling of the dispenser. The dispenser 400 also includes a valve 420, through which valve 420 air may be pumped into the interior 406 for reasons described below.

Referring now to fig. 17, a cross-sectional view of the dispenser 400 is shown to more clearly see its interior 406 and its function. An internal chamber 422 is defined at the dispenser 400, the internal chamber 422 being configured for storing and then rapidly dispensing feed for abalone. The interior chamber 422 can, in some embodiments, include a piston 424, which piston 424 is operable to rapidly move in a downward direction (see fig. 17) after the lid 404 is opened, to enable rapid ejection of food contained therein from the chamber 422. Because food will be deployed in an underwater environment and water will flow quickly into chamber 422 once lid 404 opens, it is generally preferable to spray food quickly so that the inflow of water does not result in the full amount of food being dispensed. The piston 424 may be operated by any suitable mechanism (not shown), such as by a spring mechanism or by compressed air (e.g., pumped through the valve 420). In some embodiments, piston 424 may not be required, for example, internal chamber 422 may be pressurised with air so that when lid 404 is opened, air and the abalone feed entrained with it is ejected very rapidly out of chamber 422.

Referring now to fig. 18, there is shown a dispenser 400 (in a lid open configuration) screwed into the feeding port 332 of the upper half 302 of the tube 300 (tube 301 may instead be shown as described above). As can be seen, the thickness of the threaded portion 402 of the distributor 400 is about the same as the thickness of the wall of the pipe 300 such that a substantially flush surface is provided therebetween (which may help reduce biofouling). Further, in its open configuration, the lid 404 is positioned such that it does not impede removal of the used dispenser 400 from the tube 300 (e.g., during inspection and refilling). The operator need only unscrew the dispenser 400 from the tube 300 and remove it directly from the tube 300.

Since abalone will tend to move around in the interior of the tube 300, it will generally be necessary to protect the opening of the dispenser 400 from abalone resting on or above the opening, which may prevent the lid 404 of the dispenser 400 from opening. One way in which this protection can be achieved is to use a shield 426, typically made of a mesh material, which shield 426 will allow water and feed to pass through it but will not allow abalone to pass through it. The shroud 426 may be made, for example, of the same stainless steel mesh described above, over which abalone may crawl and clean in a similar manner. As can be seen, the edge of the shroud 426 abutting the inner wall of the tube 300 should be substantially coplanar with the surface, otherwise biofouling may occur at the raised edge. The edges of the shroud 426 may be slightly recessed, for example, into the inner wall of the tube 300, but this may not be necessary if the material from which the shroud 426 is made is sufficiently thin.

In use, the operator will select the appropriate dispenser 400, the dispenser 400 being filled with feed for abalone and its lid closed. The dispenser may, for example, be color-coded to indicate the type or amount of feed contained therein (e.g., suitable for a particular size of abalone) or to indicate a delay before the lid 404 is opened. In embodiments where the tube 300 has three feeding ports 332, the operator will select three appropriate dispensers 400 and screw them into their respective ports. In alternative embodiments (not shown), the dispenser may be adapted to be securely received in the feeding port by a snap fit, bayonet fit, friction fit, or the like.

Each of the dispensers 400 will be configured to open its lid at predetermined intervals as described above and thus dispense the feed contained therein into the tube 300. For example, a red dispenser may be configured to open its lid after 1 week, an orange dispenser after 2 weeks, and a green dispenser after 3 weeks. After one week of opening the lid of the green dispenser, it is planned that tube 300 will be removed from the water at this point, inspected for abalone and three used dispensers 400 replaced with new dispensers 400.

In an alternative embodiment (not shown), the dispenser 400 may include a signal receiver that causes the lid 404 to open upon receipt of an appropriate signal. In this way, signals generated by an external source (e.g. by a computer system managing an abalone farm) may be used to control the rate at which abalone is fed into tube 300/310. The dispenser 400 may also include a transmitter (also not shown) that transmits a signal if a predetermined event occurs (e.g., the lid 404 is not open). Receipt of such a signal will trigger an appropriate alarm, for example, tube 300/301 not being retrieved as planned, in order to feed abalone and replace the failed dispenser.

Referring now to figures 19 and 20, there is shown a portion of an offshore farm for raising abalone. As best shown in fig. 19, the long rope 500 is anchored to the sea floor using concrete blocks 502 (or other suitable means) at either end. A number of floating bodies (shown generally as floating bodies 504) are positioned along the length of long ropes 500 and maintain long ropes 500 only at desired distances below the surface of the water. A number of pipes 300 (pipes 301 may be used instead or in addition) are tethered to the long ropes 500 and suspended below the water surface. The long rope 500 may have any length, and in the embodiment shown is about 100m long. The six buoyant bodies 504 are substantially evenly spaced along the long rope 500 with four tubes 300 depending between adjacent buoyant bodies 504 (i.e., there are twenty tubes 300 in total for the long rope 500).

The length of ascent from anchor 502 to first floating body 504 may be about 10 meters, but may be adapted to be lengthened or shortened to account for tides and water depths. However, even where the ascending portion is stationary and the farm includes other long ropes in the vicinity (typically, such long ropes will be arranged parallel to one another and approximately 30m apart), each long rope and its associated pipe will tend to float in the same direction as the tidal flow, preventing interference therebetween.

Referring now to fig. 20, the tube 300 is shown suspended from the long tether 500 by tethers 506, the

tethers

506, 506 being attached to

apertures

318, 318 at the distal end of the upper half 302 of the tube 300. The tethers 506,506 are of a length such that the tube 300 overhangs the water surface by approximately 1m, which has been found to be an ideal abalone growth depth. As will be described in more detail below, the tube 300 suspended from the long rope 500 can be lifted from time to time onto a boat for maintenance, feeding, inspection etc. of the abalone, usually without having to use divers.

Referring now to fig. 21 and 22, there is shown a boat 600, the boat 600 having two

retrieval devices

602, 602 on one side thereof. The boat 600 includes a substantially flat work area 604 on which the tube 300 (or 301) can be placed and opened for visual inspection and feeding of abalone contained therein. In some embodiments (not shown), the substantially flat working area may be provided in the form of a deck that can be slid out from the side of the boat 600, which may help make the pipes 300 suspended adjacent the boat even more accessible.

The

retrieval devices

602, 602 are adapted to lift the long rope 500 and any tube 300 thereon. In use, the boat 600 is stopped alongside the long rope 500 and the long rope is lifted (e.g. after hooking with a hook, the long rope may then be lifted mechanically or manually) so that it engages both devices 602, 602 (as will be described below). Once so positioned, long rope 500 is raised alongside boat 600 so that the tube 300 hanging from long rope 500 can be easily accessed by personnel on the boat. The spacing between the

devices

602, 602 at the distal end of the work area 604 ensures that the boat 600 remains substantially parallel to the long rope 500, regardless of any wind or water currents that may act on the boat.

Referring now more particularly to fig. 22, an enlarged view of one of the retrieval devices 602 is shown. The device 602 includes an arm 606 for engaging the long rope 500. Arm 606 is coupled to boat 600 by boom pivot 608 so it is stowed away when not in use (i.e., the stowed device 602 will not hang over the side of the boat). The device 602 also includes a cord-engaging means 610 for engaging the long cord 500 in use. As is apparent from the inwardly tapered configuration of the cord engaging device 610, the cord engaging device 610 is adapted to frictionally engage the long cord 500 in use. The rope engagement device 610 is rotatable so that the boat 600 can travel along the long rope 500 (using its own motor or by a motor or hydraulic motor (not shown) within one or both of the apparatus 602, 602) to service the pipe 300 along the way.

The cord engagement device 610 defines a space therein for engaging the long cord 500, the space being defined by an inner disc member 612 and an outer disc member 614. The inner disc member 612 may include one or more raised members (shown generally at 616) on an inner surface thereof and adapted to frictionally engage the long rope 500 (i.e., in order to grasp the long rope 500 and drag the boat 600 along the long rope 500). The inner disc member 612 may also include edgewise positioned teeth, shown generally at 618 (see also fig. 21), for receiving and engaging one or more tethers 506, in use. In this manner, teeth 618 provide clearance in which tether 506 may be received, thereby ensuring that tube 300 (and any tether securing float 504) is engaged by inner disc member 612. In this manner, rotation of the inner disc member 612 causes the boat 600 to be dragged along the long rope 500.

The retrieval device 602 also has a rope guide 620, the rope guide 620 being a curved track adapted to guide the long rope 500 towards the rope engaging means 610 and onto the rope engaging means 610 in use. The rope guide 620 also guides the tether 506 for the tube 300 and floating body 504 between the rope guide 620 and the boat 600 to reduce the risk of the tether 506 becoming entangled within the rope guide 620. Rope guide 620 extends forward toward the bow of boat 600 and rearward toward the stern of boat 600.

In use, boats 600 with

retrieval devices

602, 602 are dispatched at periodic intervals to feed, maintain, inspect or collect the tubes 300 suspended from the long ropes 500. Boat 600 is stopped alongside long rope 500, lifting long rope 500 and then engaging it into

rope engaging devices

610, 610. As the boat 600 moves along the long rope 500, the pipe 300 suspended from the long rope 500 is lifted out of the water and to a convenient location where the pipe 300 can be accessed from the edge of the boat 600 (as can be seen in fig. 21) for inspection and/or maintenance of the pipe. If necessary, the tube 300 can be positioned over a working area 604 where the tube 300 can be opened to inspect the abalone and the conditions inside the tube. The rope engaging device 610 is hydraulically rotated to drag the boat 600 along the long rope 500 to repeat this process for each of the tubes 300 on the long rope 500. Once all of the tubes 300 on a particular long rope 500 have been inspected, the boat 600 may turn around and repeat the process for another long rope (not shown). In this way it is possible to inspect a considerable number of tubes 300 containing abalone without necessarily requiring divers or without having to perform any onerous lifting. As will be appreciated, this will significantly reduce the costs associated with offshore abalone farms and greatly increase their efficiency.

The boat 600 may also be provided with a storage area (not shown) which can be used to store the tubes 300 removed from the long ropes 500, since the abalones contained therein have completed their first or second offshore growth cycle (described above) and need to be appropriately graded. Such storage areas may also be used to carry newly loaded pipes 300 loaded with abalone ready to enter their first or second offshore growth cycle.

As described herein, the present invention provides improved abalone culture apparatus and methods. Embodiments of the present invention provide a number of advantages over existing abalone farming plants and methods, some of which are summarized below.

The water tank of the invention may for example be advantageous because:

providing the water tank in a modular form may simplify the construction of such water tanks;

concrete panels produced in a controlled environment are often less prone to defects (e.g. cracking, deformation, etc.) than when they are built on site;

the modular water tank can be easily mounted on the post, which eliminates the need for a foundation.

The submersible container of the invention may for example be advantageous because:

abalone is safely contained within an environment where predators cannot have access to them;

It is possible to check the abalone stock only once a month;

the vessel can be easily inspected, retrieved and deployed without the need for divers or other complex and expensive underwater equipment; and is provided with

A folding member in a depending position inside the container greatly increases the abalone carrying capacity of the container, but when unfolded allows easy removal of abalone therefrom.

Those skilled in the art will appreciate that many modifications may be made without departing from the spirit and scope of the invention. All such modifications are intended to be within the scope of the following claims.

It will also be appreciated that, although the preceding description refers to a particular sequence of method steps, apparatus and equipment parts for performing such methods, and their configuration, in relation to a particular application, such details are provided for illustrative purposes only and are not intended to limit the scope of the present invention in any way.

In the claims which follow and in the preceding description of the invention, unless the context requires otherwise (due to express language or necessary 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.

Claims

1. A water tank for growing abalone, the water tank comprising:

an elongate base comprising upstanding walls arranged parallel to a longitudinal axis of the elongate base and defining a channel therebetween for receiving a flow of water;

wherein the elongated base comprises a plurality of preformed base portions adapted to be sealingly connected together; and

one end of the elongate base being sealably connected to a water discharge for delivering the flow of water to the or each channel, and a distal end of the elongate base being sealably connected to a water discharge;

the tailer comprising a trough extending across the width of the elongate base and wherein water delivered into the trough of the tailer flows into the or each channel;

the drain comprises a trough extending across the width of the elongate base and wherein water that has passed through the or each channel drains into the trough of the drain;

wherein the water discharger and the water drain are configured to discharge water and drain, thereby alternating the direction of water flow within the or each channel.

2. The water tank of claim 1, wherein the elongated base includes a plurality of channels.

3. The water tank of claim 1, wherein a width of the elongated base is defined by a width of one of the pre-formed base portions.

4. The water tank of claim 1, wherein a length of the elongated base is defined by a length of two of the pre-formed base portions.

5. The water tank of claim 1, wherein an edge of one of the pre-formed base portions comprises a protrusion configured to be sealingly received in a corresponding recess at an edge of another of the pre-formed base portions.

6. The water tank of claim 5, wherein the plurality of pre-formed base portions are substantially identical to one another.

7. The water tank of claim 1, wherein the water discharger and the water discharger are identical to each other.

8. A cistern system comprising a plurality of cisterns as claimed in any one of claims 1 to 7 arranged in an array.

9. The water tank system of claim 8, comprising:

two tanks as claimed in claim 1 wherein the tanks are arranged in series along the longitudinal axis of their elongate base and the end of one tank is located adjacent to the end of the other tank; and

A central trough located between and sealingly connected to the elongated bases of adjacent ends of the tank, the central trough selectively operable to deliver a flow of water into the passage of the tank or to drain water delivered into a distal end of the passage of the tank.

10. The water tank system of claim 9, further comprising an elevated platform above the central trough, the elevated platform adapted to receive a reservoir thereon, the reservoir operable to deliver a water wave into one or more of the channels.

11. The cistern system as claimed in claim 10, wherein said water reservoir is slidable along a track provided on said elevated platform such that it is aligned with a selected one or more of said passageways.

12. The water tank system of claim 10, wherein said water reservoir is pivotable toward either water tank, whereby said water waves can be delivered to a selected one or more of said channels.

13. The water tank system of claim 9 further comprising an abalone feeding device adapted to move along the length of each raceway and broadcast food into the raceway.