NO20210040A1

NO20210040A1 - Operation of a floating fish farm

Info

Publication number: NO20210040A1
Application number: NO20210040A
Authority: NO
Inventors: Per Kristian Bruun; Kristoffer Kjellså Jakobsen; Andreas Jo Falk Fredborg; Pål Lindstad
Original assignee: Aker Solutions As
Priority date: 2021-01-12
Filing date: 2021-01-12
Publication date: 2022-07-13
Also published as: NO346673B1

Description

OPERATION OF A FLOATING FISH FARM

The present disclosure relates to an offshore fish-farm and preferable operation of said offshore fish-farm.

BACKGROUND

The use of fish farms to rear fish is widely known, and such farms are often used to rear large numbers of fish within an enclosure, thereby reducing strain and reliance on wild fish populations to satisfy consumer demand for fish products. Fish farms may be arranged offshore, such as in the sea or ocean, or in some cases a fish farm may be positioned in a river or in another body of water, e.g. in a natural lake, or in an artificially created body of water.

SUMMARY

A first aspect relates to a fish farm comprising:

a first enclosure,

a second enclosure;

the first enclosure being connected to the second enclosure by an access arrangement for selectively permitting movement of a fish between the first enclosure and the second enclosure;

the first enclosure and the access arrangement being positioned within the fish farm such that both the first enclosure and the access arrangement are fully submergible when positioned in a body of water.

According to a second example, the fish farm may comprise a restrictor arrangement in cooperation with the access arrangement for selectively permitting access between the first and second enclosures.

According to a third example, the restrictor arrangement may be located in the access arrangement.

According to a fourth example, the restrictor arrangement may selectively prevent movement of fish between the first enclosure and the second enclosure. Having such a restrictor arrangement may permit a user to control movement between the enclosures of the fish farm, by permitting or restricting access of a fish between the enclosures.

According to a fifth example, the restrictor arrangement may comprise a plurality of rigid bars with spaces therebetween for permitting a fish to pass therethrough.

According to a sixth example, the restrictor arrangement may comprise a first and a second set of rigid bars , each set having spaces therebetween for permitting a fish to pass therethrough, the first set of rigid bars being slidably may be moveable relative to the second set of rigid bars between an open position (as shown in Fig.5b), in which the spaces between the rigid bars of the first and second set of rigid bars are aligned, and a closed position (as shown in Fig.5a), in which the rigid bars of the first set of rigid bars are aligned with the spaces of the second set of rigid bars, thereby restricting passage of a fish therethrough.

According to a seventh example, the first set of rigid bars may be positioned relative to the second set of rigid bars such that the bars of the first set of rigid bars partially overlap with the spaces of the second set of rigid bars, thereby reducing the space available for passage of a fish therethrough.

According to an eighth example, each of the bars in the first set of rigid bars may be parallel to each other, and each of the bars in the second set of rigid bars may be parallel to each other, and the first set of rigid bars may be arranged such that the bars are parallel to the second set of rigid bars.

According to a ninth example, at least one of the first and second sets of rigid bars may be remotely moveable by a user. Having a plurality of rigid bars, which may comprise a moveable first and second set, may permit a user to provide a variable degree of restriction in the restrictor arrangement, thereby permitting the restrictor arrangement to only restrict the passage of fish therethrough above a certain size, which may be able to be determined by said user.

According to a tenth example, the fish farm may comprise a sensor arrangement comprising a counter for counting the number of fish passing through the access arrangement.

According to an eleventh example, the fish farm may comprise a sensor arrangement comprising a sensor for measuring the size and biomass of each fish passing through the access arrangement.

According to a twelfth example, fish farm may comprise a restrictor arrangement and the sensor arrangement may provide data to a user or a control system for enabling selective access between the first and second enclosures. Having a sensor arrangement located so as to permit sensing such as counting or size/biomass analysis of each fish passing through the access arrangement may provide the user with a convenient and accurate method for measurement. Coupling the sensor arrangement with the access arrangement may ensure that all, or a significant portion, of the fish passing through are sensed by the sensor arrangement. In contrast, other systems may attempt to measure the number and biomass of fish in a fish farm by scanning the fish in an enclosure, which technique may not be able to individually analyse each fish, and may require estimations or guesswork, thereby decreasing the level of accuracy of such systems.

Where the sensor arrangement is connected to a control system for operating the access port and/or a lure arrangement(s), this may enable a user to turn the sensor arrangement on when necessary, receive information from the sensor arrangement such as information relating to the biomass of the sensed fish, information relating to the status of the restrictor arrangement, or the like. In addition, it may enable a user to control the restrictor arrangement based upon the information provided by the sensor arrangement, such as closing the restrictor arrangement once a desired weight/biomass of fish has passed through the restrictor arrangement, estimating the biomass of fish that have passed through the restrictor arrangement (e.g. by estimating the average biomass of each fish), providing a statistical representation of the differing weights of fish that have passed through the restriction arrangement and optionally adjusting the lure arrangement and/or to monitor the health condition of the fish passing through the restrictor arrangement etc..

According to a thirteenth example, the access arrangement may comprise a first and a second access port located in each of the first and second enclosures and the sensor arrangement is located adjacent at least one of the first and second access ports.

According to a fourteenth example, the access arrangement may comprise a shaft extending between the first and the second enclosure.

According to a fifteenth example, the access arrangement comprises an aperture, and the first enclosure comprises an entry port directly connected to an entry port of the second enclosure.

According to a sixteenth example, the access arrangement may comprise a conduit extending between the first and the second enclosure. The access arrangement, and optionally the conduit may provide access in one direction, for example by comprising a one-way opening such as a unidirectional flapper, or a flapper that is able to be configured between unidirectional (the direction of which may be selectable by a user) and a bidirectional configuration if required. The configuration of the one-way opening may be controlled remotely by a user, e.g. wirelessly, who may be able to decide in which direction(s) access through the flapper is permitted. In some examples, the access arrangement may be or define a flexible sleeve. The flexible sleeve may be held open at one end, thereby permitting a fish to swim easily through the flexible sleeve from the end that is held open, but making passage in the opposite direction more difficult. As such, the flexible sleeve may function as a one-way opening.

Having an access arrangement comprising an aperture, and optionally a conduit may permit the access arrangement to connect enclosures in various configurations of fish farm, and may enable the structure of a fish farm to be reconfigured (e.g. enclosures within the fish farm moved) while still permitting functioning of the access arrangement.

According to a seventeenth example, the fish farm may comprise a third enclosure, and the access arrangement may be configured to selectively permit movement of a fish between the third enclosure and at least one of the first and second enclosures.

According to a eighteenth example, the access arrangement may permit movement of a fish between the first and third enclosure via the second enclosure.

According to an nineteenth example, the second enclosure may be located above the first enclosure.

According to a twentieth example, the second enclosure may be smaller than the first enclosure. The second enclosure may therefore be conveniently replaced for removal from a fish farm. Additionally, having the second enclosure be smaller than the first enclosure may limit the number of fish therein, making removal of the second enclosure easier, and ensuring a vessel for removing fish from a fish farm is not overwhelmed by the number of fish in the second enclosure.

According to a twenty-first example, the first and second enclosures may comprise or may be connected to a ballasting system to permit the draft (i.e. the height of the first and second enclosures relative to the surface of the surrounding fluid) of the first and second enclosures to be varied.

According to a twenty-second example, both the first and the second enclosures may be completely submerged in a subsea location. As such, the location of the enclosures may protect the fish therein, for example from waves, sea lice and from surface predators.

According to a twenty-second example, the fish farm may comprise an extraction conduit at least partially located in at least one of the enclosures for removal of a fish therefrom.

According to a twenty-third example, the fish farm may comprise a surveillance system for monitoring movement of a fish in at least one of the enclosures of the fish farm. The surveillance system may assist a user to know where in the fish tank the fish are mainly located, which may be useful in times where the fish are required to be removed from the fish farm.

According to a twenty-fourth example, the fish farm may comprise a lure arrangement for motivating movement of a fish from the first enclosure to the second enclosure.

According to a twenty-fourth example, the lure arrangement may comprise at least one of: a supply of fish feed, , an air pocket, a light source, a source of sound (e.g. a speaker or sound transmitter), a source of an attractive or a repulsive smell and a fluid propeller. The lure arrangement may be attractive to a fish, may be repulsive to a fish, or may comprise some degree of attraction and some degree of repulsion to a fish (for example so as to repel fish from one enclosure while simultaneously attract said fish to a second enclosure).

According to a twenty-fifth example, the lure arrangement may be located in each enclosure of the fish farm.

According to a twenty-sixth example, the lure arrangement may be able to be selectively activated within an enclosure of the fish farm. As such, the lure arrangement may be activated to lure fish to a desired enclosure.

According to a twenty-seventh example, at least one of the first and second enclosures may comprise a volume restriction device for reducing the volume of space available to a fish therein.

According to a twenty-eighth example, the volume restriction device may be in the form of a sliding bulkhead.

According to a twenty-ninth example, the sliding bulkhead may comprise a net material. According to a thirtieth example the sliding bulkhead and at least one enclosure may each comprise a profile, the profile of each configurable to engage so as to control the position of the bulkhead.

In other examples, volume restriction may be achieved by de-ballasting the fish farm to raise the height of the fish farm above the water surface, such that at least a portion of at least the first and/or second enclosure is located above the water surface, thereby using the water surface as a form of volume restriction device. Use of a sliding bulkhead in the first and/or second enclosures may be in addition to de-ballasting the fish farm to form a volume restriction device.

According to a thirty-first example, both the first and second enclosures may be contained within an outer enclosure.

According to a second aspect, there is provided a method for managing fish in a fish farm, comprising:

providing a first enclosure and a second enclosure, the first enclosure being connected to the second enclosure by an access arrangement for selectively permitting movement of a fish between the first enclosure and the second enclosure;

housing a fish in the first enclosure;

permitting a fish in the first enclosure access to the second enclosure by positioning the first enclosure and the access arrangement such that both are fully submerged when positioned in a body of water.

According to a second example of the second aspect, the method may comprise using the lure arrangement to motivate a fish to move from the first enclosure to the second enclosure, or from the second enclosure to a third enclosure. The lure arrangement may be attractive to a fish, repulsive to a fish, or have a combination of both attractive features and repulsive features. As such, the lure arrangement may be used to repel a fish from the first enclosure and into the second enclosure, while at the same time being used to attract a fish from the first enclosure to the second enclosure, thereby increasing the efficacy of the lure arrangement.

According to a third example of the second aspect, the method may comprise extracting a fish from the second enclosure.

According to a fourth example of the second aspect, the method may comprise closing the access from the first enclosure to the second enclosure and detaching the second enclosure from the fish farm.

According to a fifth example of the second aspect, the method may comprise housing a plurality of fish in the first enclosure, and housing a plurality of fish in the second enclosure, and feeding the plurality of fish in the first enclosure regularly, while starving the fish in the second enclosure.

A third aspect relates to a fish examination system for a fish farm, the fish examination system comprising:

a fish retrieval arrangement for retrieving a fish from an external location and providing the fish to the fish examination system;

at least one examination station comprising a primary check station for conducting at least one non-invasive examination of a fish;

an exit station for receiving a fish from the primary check station;

a control system for receiving and storing examination data from the at least one examination station.

According to a second example of the third aspect, the at least one examination station may additionally comprise a sample station for extracting a physical sample from the fish and optionally performing an internal examination of a fish.

According to a third example of the third aspect, the fish examination system may comprise a fish positioning system comprising at least one of:

a buffer arrangement for temporary storage of a fish,

a transport arrangement for moving a fish in the fish examination system.

According to fourth example of the third aspect, operation of the fish positioning system may be conditional on the examination data stored by the control system.

According to a fifth example of the third aspect, the control system is configured to count the number of fish retrieved by the fish retrieval arrangement.

According to a sixth example of the third aspect, the control system may be configured to compare the examination data with a database of fish sample data.

According to a seventh example of the third aspect, the at least one examination station may additionally comprise an autopsy station comprising a robotic autopsy device for performing an autopsy on the selected fish.

According to an eighth example of the third aspect, the robotic autopsy device may be a robotic arm.

According to a ninth example of the third aspect, the autopsy station may comprise a selection station, wherein each fish is considered and optionally selected for autopsy.

According to a tenth example of the third aspect, the exit port may be or comprise a grinding and ensilaging system.

According to an eleventh example of the third aspect, the fish examination system may comprise a freezer or a storage arrangement to store the fish for future examination.

According to a twelfth example of the third aspect, the sample station may comprise a storage container to store extracted samples.

According to a thirteenth example of the third aspect, the at least one fish examination station and the exit port may be arranged in an examination room.

According to a fourteenth example of the third aspect, the examination room may be located on a fish farm.

According to a fifteenth example of the third aspect, the fish examination system may comprise a cleaning and disinfection system.

According to a sixteenth example of the third aspect, the control system may be configured to autonomously conduct the examination process of the fish examination system.

According to a seventeenth example of the third aspect, the external location is a fish farm.

According to a fourth aspect, there is a method for examining the health status of a fish, the method comprising:

retrieving a fish from a fish farm;

providing the retrieved fish at an examination station;

conducting a first non-invasive examination of the fish at the examination station; providing the fish at an exit port;

storing examination data received from the examination station in a control system.

According to a second example of the fourth aspect, the method may comprise extracting a sample from the fish.

According to a third example of the fourth aspect, the method may comprise conducting the method autonomously.

According to a fourth example of the fourth aspect, the method may comprise using data stored in the control system to assist in conducting the method autonomously.

According to a fifth example of the fourth aspect, the method may comprise grinding and ensilaging the fish at the exit port.

According to a sixth example of the fourth aspect, the method may comprise providing the retrieved fish at an examination system for conducting an autopsy of the fish.

A fifth aspect relates to a fish extraction system for extracting fish from a fish enclosure, the fish extraction system comprising:

a separation compartment for separating at least one fish from a farmed fish group, the farmed fish group being in a fish enclosure, the separation compartment being selectively accessible from the fish enclosure;

an extraction compartment for extracting a fish therefrom, the extraction compartment being accessible from the separation compartment and comprising an extraction port accessible by a user to extract a fish therefrom; and

a restriction arrangement for restricting movement of a fish from the fish extraction compartment and to the fish enclosure.

According to a second example of the fifth aspect, the extraction compartment may comprise a lure therein for attracting a fish thereto.

According to a third example of the fifth aspect, the lure may be an air source.

According to a fourth example of the fifth aspect, the separation compartment may be directly connected to the extraction compartment such that they form one single compartment.

According to a fifth example of the fifth aspect, the separation compartment may be integrated into the fish farm.

According to a sixth example of the fifth aspect, the separation compartment may comprise an air pocket structure having an air pocket located therein and functions to selectively provide access to the air pocket.

According to a seventh example of the fifth aspect, the access to the extraction compartment from the separation compartment may be selectively controllable by a user, and access to the air pocket in the separation compartment may be restricted when access to the extraction compartment is permitted.

According to an eighth example of the fifth aspect, the air pocket structure may comprise means for varying the volume of the air pocket.

According to a ninth example of the fifth aspect, the restriction arrangement may comprise a selectively openable cover positioned in at least one of the extraction compartment and the separation compartment.

According to a tenth example of the fifth aspect, the restriction arrangement may permit unidirectional movement therethrough.

According to an eleventh example of the fifth aspect, the restriction arrangement may comprise a hinged cover.

According to a twelfth example of the fifth aspect, the extraction compartment may comprise a waterline.

According to a thirteenth example of the fifth aspect, at least part of the extraction compartment may be located above the water level of the body of water in which the fish farm is located.

According to a fourteenth example of the fifth aspect, the separation compartment may comprise a shifting arrangement for moving a fish from the separation compartment to the extraction compartment.

According to a fifteenth example of the fifth aspect, the shifting arrangement may comprise a moveable wall or panel for physically moving a fish from the separation compartment to the extraction compartment by gradual reduction of the space available in the separation compartment to the fish.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics will become clear from the following description of illustrative embodiments, given as non-restrictive examples, with reference to the attached drawings, in which:

Figure 1 illustrates a simplified sectional perspective view of a fish farm.

Figures 2-4 illustrate a side view of a fish farm and operation thereof.

Figures 5a-c illustrate an access unit of the fish farm.

Figure 6 illustrates a top view of the enclosures and access units of a fish farm.

Figure 7 illustrates a side view and operation of another example of a fish farm.

Figures 8-14 show an example of a volume restriction device.

Figures 15-21 show various examples of a fish farm and operation thereof.

Figures 22-24 illustrates a further example of a fish farm.

Figures 25 and 26 schematically illustrate a further example of a fish farm and equipment thereof.

Figures 27 and 28 illustrate an example of a fish examination system.

Figure 29 schematically illustrates a fish farm comprising a fish extraction system.

Figures 30 to 34 are further schematic illustrations of fish farms comprising fish extraction systems.

DETAILED DESCRIPTION

The following description may use terms such as “horizontal”, “vertical”, “lateral”, “back and forth”, “up and down”, ”upper”, “lower”, “inner”, “outer”, “forward”, “rear”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader’s convenience only and shall not be limiting.

During the course of fish farming operations, there is often the need to move a number of fish from one location to another. For example, when part of the fish farm need to be cleaned or replace. Additionally, when harvesting fish in a fish farm, the fish must be extracted from their enclosure.

Commonly, nets are used to form the enclosure and the space for the fish in the nets may be reduced, e.g. by squeezing the net structure to force the fish out of their enclosure and into a vessel, for example, where the fish may be taken to a processing centre or to another fish farm, or by forcing the fish out of a first enclosure and into a second enclosure to enable cleaning or repair of the first enclosure. While this approach provides one method of extracting fish from their enclosure, it may harm some or all of the fish as a force may be applied to the fish when reducing the space of the enclosure due to crowding with other fish, in some cases resulting in crush and/or stress induced injuries to, and potentially mortality of, the fish. In cases where the extraction or displacement of only a small number of fish is required, e.g. for sampling of live fish of for harvesting fish that have grown to a large size, this method may result in stress or injury to all fish in the fish farm, as it may not be possible to selectively extract fish from the fish farm or move fish within the fish farm. Therefore the risk of harm and/or injury to all fish in the farm is introduced. This has a negative effect not only on the fish that are desired to be harvested or moved, but also other fish that do not require to be moved or extracted, for example because they may not yet have fully matured, and/or that may be still be small in size. Ideally, such fish are intended to stay in the enclosure, where they may be allowed to grow and mature until a later time when their harvesting may be more economically viable. In some cases, it may be necessary to move a portion of the fish in the fish farm, for example because the capacity of the fish farm (or an enclosure thereof) has been reached. In this case, avoiding any stress to the remaining fish is highly desirable.

Prior to handling operations, transportation and treatment it is common practice in the fish farming industry to starve the fish, as this makes the fish more capable of handling the stress from such operation. The starving period typically lasts a few days depending on factors such as temperature, species and size of fish. Starvation can have a negative impact on fish welfare and also represents a considerable loss for the farmer in the form of lost growth. With current methods, all the fish inside a fish cage must be starved in preparation for an extraction of just a portion of the fish. It is hence an objective to limit starvation to only the fish that will be handled.

This disclosure aims at providing an apparatus and a method to move fish from or within a fish farm without harming them, as well as enabling the selection a desired amount and/or type of fish prior to extraction and facilitate starving of only the selected fish.

Figure 1 shows simplified diagram of a fish farm 100 according to the present disclosure comprising a first enclosure 130. The fish farm 100 is located in a body of water, which may be the sea or ocean. The fish farm 100 comprises a floating structure 104 having a positive buoyancy. The floating structure 104 comprises a lower pontoon collar 102 which may assist to provide buoyancy to the floating structure 104. The lower pontoon collar 102 may be hollow, or comprise a hollow portion thereof, and/or may comprise or be constructed from a buoyant material such as a buoyant foam or plastic, and/or may comprise buoyant members connected thereto, such as buoys or foam flotation members. The lower pontoon collar may additionally comprise means to selectively alter the draft thereof (as well as the draft of the floating structure 104 of the fish farm), e.g. a fluid inlet and a pump for pumping water into and out of the lower pontoon collar 102 in a ballast arrangement to alter the height of the lower pontoon collar above the water level. The floating structure 104 may additionally comprise an upper collar 103 which may assist to provide additional stability to the fish farm 100 when located in an offshore location. The upper collar 103 may have an open top section to permit easy access to the fish farm 100, or may comprise a cover, net, mesh or the like having a hatch or opening therein through which the fish farm 100 may be accessed. In addition, the upper collar 103 may comprise an access structure (not illustrated in Figure 1) to facilitate access to the fish farm 100 by a user. The access structure may be in the form of a metal frame and/or platform on which a user may be able to stand, balance against, position equipment, secure a floating vessel thereto etc.. The lower pontoon collar 102 and the upper pontoon collar 103 are connected by an arrangement comprising columns and/or trusses 101 in this example. In some examples, the fish farm 100 may comprise an additional or alternative arrangement to provide stability and buoyancy to the first enclosure 130, e.g. a system of tensioned ropes or a frame surrounding the first enclosure 130.

Below the floating structure 104 a first net 105 is arranged. In this example the first net 105 has a cylindrical shape, one end of which is conically shaped. In another example, the first net 105 may have a different shape, e.g. may be cuboid, conical, frusto-conical, or in the form of some other extruded polygonal. In some examples the first net 105 may comprise no bottom part 105a or may comprise a bottom part 105a of another shape, for example a pyramidal shape, a dome shape or the net may be flat-bottomed, in this case meaning that the bottom part would comprise a circular shape. The first net may comprise or be connected to a top net 106. The top net 106 may form one end of the cylindrical shape of the first net 105, such that the top net 106 has a circular form. In some examples, the first net 105 may not be in the form of a cylinder, but another shape (e.g. another extruded shape) and the top net 106 may be shaped correspondingly so as to form an enclosure in combination with the first net 105. The shape of the top net 106 may correspond to the shape of an opening in the first net, such that the top net 106 is able to close the opening, if necessary. For example, where the first net 105 has the shape of an extruded pentagon, then the top net 106 may be pentagonal in shape. The top net 106 may lie above the water surface, or below the water surface depending on the draft of the fish farm 100. The first net 105 and the top net 106 may together form a first enclosure 130 for the fish. Located above the top net 106 in this example is a cover 112, which in this example is a net or membrane that may be permeable to water. The cover may assist to provide protection to the fish farm, for example from predators such as seabirds and may additionally assist to prevent fish from leaping from the fish farm 100. A further enclosure may therefore be formed between the top net 106, the cover 112 and a peripheral net 114. In some examples, it may be possible to insert a vertically extending net (not shown) between the cover 112 and the top net 106, which may be used to divide the enclosure between the top net 106 and the cover 112 into further enclosures.

As illustrated, surrounding the first net 105 is a second net 111. The second net 111 may be arranged as a double barrier to protect against damage to the enclosure 130 (e.g. to protect against damage to the first net 105 of the enclosure) and additionally to protect the fish contained in the enclosure 130 e.g. by keeping predators away or by reducing impact forces of objects hitting the fish cage. The second net 111 may additionally assist to improve the security of the fish farm 100 by assisting to prevent escape of fish from the enclosure 130, should there be a breach in the first net 105. Provided sufficient spacing between the nets, two independent incidents involving damage to both nets would be required in order for fish to escape, thereby drastically reducing the chances of fish escape.

The first net 105 and second net 111 may be secured together by a securing arrangement. For example by using a series of connectors 113 such as rope or ties that may be held in tension between the nets, thereby restricting the movement of the first net 105 relative to the second net 111 which may improve the stability of the fish farm 100 by preventing erratic movement of the first net 105 inside the second net 111. The securing arrangement may be located on the first net 105 at the interface between the first net 105 and the bottom part of the first net 105a, while the securing arrangement may be located on the second net 111 at the interface between the second net 111 and a bottom part of the second net 111a. The securing arrangement may, in some examples, connect the first net 105 and the second net 111 together at the interface between each net 105, 111 and the respective bottom part 105a, 111a thereof. The securing arrangement may comprise a frame structure or two frame structures, and the frame structure or structures may be connected to one or both of the first and/or second nets 105, 111. The frame structure may be the same shape as the net to which it is attached, e.g. the same shape as the cross-section of the net 105, 111 to which it is attached. In this example, the frame structure may be circular in shape as the first and second nets 105, 111 are cylindrical in shape.

In some examples, there may be a weighting element attached to the first and second net 105,111, e.g. a metal collar, a collar filled with a weighted material such as cement or any other material with a density greater than that of the surrounding water of the fish farm 100, a plurality of weighted capsules or other components, etc.. The weighting element may assist to provide tension in the first and second net 105,111 in a direction in which the first and second nets 105, 111 extend (e.g. in a vertical direction) and reduce deformation or movement of the enclosure 130 (e.g. of the nets 105, 111 in the enclosure) due to external forces such as those caused by wave motion and sea/ocean currents. As such, having a weighted element may assist to improve the stability of the enclosure 130 of the fish farm by reducing the movement thereof.

The weighted element may be positioned on or connected to either or both of the first and second nets 105, 111, and may be located at or towards the lower end of the first and second nets 105, 111 at the connection between the first and second nets 105, 111 and the pontoon structure 104 (e.g. the lower pontoon collar 102). The weighted element may be positioned around the periphery of the first and/or second nets 105, 111, and may be positioned in a single plane (e.g. may be positioned at a constant vertical location). The weighted element may, in some examples, comprise a plurality of weighted components, positioned at a plurality of locations on the fish farm 100. The weighted element may be flexible or may be a rigid continuous structure. In the case of a rigid weighted element, the weighted element may additionally assist to prevent deformation of the nets. The weighted element, or an additional weighted element, may be provided at the interface between the first and/or second net 105, 111, and the respective bottom part of one or each of the first and second nets 105, 111, thereby assisting to hold the first and/or second nets 105, 111 in tension in the water.

At least a part of the conical section of the first enclosure 130 may be or comprise a reinforced material – in this example, the vertex of the conical section of the first enclosure 130 comprises a reinforced material. Here, the vertex of the conical section of the first enclosure 130 is located at the lowermost point of the first enclosure 130. The vertex of the conical section of the first enclosure 130 may comprise a mort collection system 131 for removing mort, i.e. dead fish and optionally other detritus, from the first enclosure 130 which may naturally sink to the vertex of the bottom part 105a, being the lowest point in the first enclosure 130. The mort collection system 131 may be connected to a fish transport means 2002 which will move the collected mort to a mort processing unit, e.g. by using a flow of water to transport the collected mort. The second net 111 has a similar shape relative to the first net 105 comprising a cylindrical shape with a conically shaped end. In another example, the second net 111 may have a different shape, e.g. cuboid or may have a shape differing from the first net 105. The bottom of the conical section of the second net 111 may also be reinforced as shown in Figure 1.

In this example, the fish farm 100 is fixed to its offshore location by an anchoring system comprising multiple lines 120a-e such as wires, chains, ropes, or the like, which may be anchored to the seabed or some other static location such as shore, a moored frame or subsea infrastructure.

Figures 2-4 show a side view of a fish farm 200 which is substantially similar to that as previously described. As such, similar reference numerals will be used to describe similar components, augmented by 100.

The fish farm 200 is illustrated comprising a first enclosure 230 and a second enclosure 240, Figures 2-4 representing a method of operating the fish farm 200 according to the present disclosure. Here, the first enclosure 230 and the second enclosure 240 are connected by an access unit 251 which is comprised in an access arrangement 250. In this example, the fish farm 200 comprises a third enclosure 232. Here, the first enclosure 230 may be substantially similar to the third enclosure 232, in that both are the same or a similar shape, and both are connected to a floating structure of the fish farm 200. The third enclosure 232 is connected to the second enclosure 240 by second access unit 252 belonging to the access arrangement 250, such that in this example the fish farm 200 may comprise several access units. For example, the number of access units may correspond to the number of enclosures present. The number of access units may be one fewer than the number of enclosures present, or more than this in the case where there is more than one access unit present between any two enclosures. Both the first and the third enclosures 230, 232 are completely submerged below the surface of the water 290, as is the access arrangement 250. The second enclosure 240 is located closer to the water surface 290 in this example, and may not be completely submerged in the water. As such, at least a part of the second enclosure 240 may be located above the water surface 290, which may be useful in times when it is required to crowd fish in the second enclosure 240, as will be described in more detail in the following paragraphs.

In this Figure, the second enclosure is located above the first enclosure 230 (and the third enclosure 232), and is located in the floating structure 204 of the fish farm. It should be noted, however, that the second enclosure 240 is not required to be located above the first and optionally the third enclosure in all examples. The second enclosure 240 may be positioned on the same level as (e.g. to the side of) the first and/or third enclosure 230, 232, or any other enclosure that may be equivalent to the first/third enclosure. The second enclosure 240 is secured to the floating structure 204, in this example by ropes or ties 258, and here occupies a volume that is smaller than the floating structure 204. The second enclosure 240 may be made from a flexible net structure that is supported by ropes or ties 258, or may be made from a collection of rigid net panels to form a rigid frame structure, with netting located in the frame openings. In some examples, the second enclosure 240 may be made from rigid panels (e.g. of steel or plastic) which may be water permeable, or in some examples the rigid panels may not be water permeable, in which case a water circulation system may be provided, for example through use of a fluid pump arrangement. The size of the second enclosure 240 relative to the floating structure 204 may permit the second enclosure 240 may be held below the water surface. To illustrate this point by way of example, where the floating structure 204 is 20 metres in height, the second enclosure may be 10 metres in height, such that it extends half-way up the height of the floating structure 204, and is located at least 10 metres below the water surface, which may be recognised as being sufficient to assist to protect fish inside the second enclosure 240 from surface predators, waves, sea lice etc.. In some examples, the second enclosure 240 may be able to be moved within the floating structure 204. The second enclosure 240 may be able to be moved closer to the water surface, which may be useful for removing the second enclosure 240, for example for cleaning purposes, or when the fish inside the second enclosure 240 are desired to be removed from the fish farm 200.

Here, the access arrangement 250 enables selective access between the first enclosure 230, the second enclosure 240 and the third enclosure 232. Access between the first enclosure 230 and the third enclosure 232 may be via the second enclosure 240, as is the case in this example. Here, the access arrangement 250 is horizontally oriented, as the second enclosure 240 is located above the first/third enclosure 230, 232. However, in examples where the second enclosure 240 is located to the side of the first/third enclosure 230, 232, then the access arrangement 250 may be vertically oriented.

The access arrangement 250 and the selective access between the enclosures 230, 240, 232 will be described in detail referring to Figures 5a-c. In another example, there may be two enclosures, e.g. the first and second enclosure 230,240 and the access arrangement 250 may enable access between these two, comprising only one single access unit 251. In yet another example, the first and third enclosure 230,232 may be present and the access arrangement 250 may enable direct access between these two, the fish farm 200 thereby comprising only one access unit 251 leading directly from the first to the third enclosure 230, 232. The access arrangement 250 comprises entry ports at the enclosures 230,232,240 to connect one enclosure to another enclosure 230,232,240 as will be shown in detail in Figures 5a-c. In addition to an entry port or entry ports, the access arrangement 250 may comprise a shaft (e.g. a hollow shaft) extending between the entry ports to connect the enclosures 230,232,240 to permit passage between the entry ports, and thereby the enclosures 230,232,240. In other examples the access arrangement 250 may comprise a tubular or conduit that connects the entry ports, thereby assisting to bridge any gap that may be present between at least two of the enclosures 230,232,240, while still permitting passage of a fish therebetween. In such examples, a shaft, tubular or conduit may enable the passage of fish between two enclosures that are not directly adjacent. In another example, the access arrangement 250 may be configured such that the entry ports of the different enclosures 230,232,240 are directly connected to one another, for example in cases where at least two of the enclosures 230,232,240 are sufficiently close that no connecting shaft, tubing or conduit is necessary.

The fish farm 200 of the described example comprises a lure arrangement, the lure arrangement comprising lure units 245a-c being arranged in the first, second and third enclosure 230,232,240 respectively for the purpose of luring a fish to the lure unit 245a-c in each of the enclosures 230,232,240. In some examples, there may be multiple lure units 245a-c in each, any or all of the enclosures 230,232,240 or there may be lure units 245a-c only in selected enclosures 230,232,240 (e.g. not all enclosures 230, 240, 232 may comprise a lure unit, but only an enclosure where the luring of fish thereto is desired) and in some examples the fish farm may not require any lure arrangements to be contained therein. The lure units 245a-c may be attached to the nets forming the enclosures 230,232,240, may be attached to the floating structure 101,102,103 introduced in Figure 1, may be connected to the access arrangement 250 or may be suspended in lines from nets, e.g. those nets forming the enclosures in the fish farm 200, or suspended from the structure. The lure arrangement 245 a-c is designed for luring the fish thereto, e.g. by distributing a supply of fish feed, by providing an oxygen supply, by providing access to air for swim bladder adjustment, by shining a light on the fish, on an area of the enclosure or on the water surface, by using sound signals or by releasing an attractive or repulsive smell, or by using a fluid propeller to create a fluid flow, which may lure the fish thereto as a result of a natural desire to swim against a flow of water – the fluid flow may be directed through an access arrangement 250, for example which may then encourage a fish to swim from one enclosure to another separate enclosure via the access arrangement. For example, the lure arrangement 245a-c may be in the form of a lamp or light source, for example an ultraviolet light source, to which fish may be attracted. A fish may be attracted directly to a light source, or may be attracted to light from the light source reflecting off a water surface in the fish farm, or to an area inside the fish farm that is lit up. Alternatively, the lure arrangement may be in the form of a supply of fish feed, a pocket of air, or a combination of all of the aforementioned. As well as using attraction to move fish inside the fish farm 200, the lure arrangement may also use repulsion, or a combination of both attraction and repulsion to move the fish in the fish farm 200. For example, access to an air supply or air pocket may be blocked or restricted in one enclosure, thereby repelling a fish away from one enclosure into another, where an air supply or air pocket may be more regularly available. Additionally, sound or light may be used that are unpleasant to a fish, thereby encouraging the fish to move away from the vicinity thereof.

In some cases, the fish may be starved for a period of time (e.g. a meal, a day or a few days) in one enclosure in order to increase the efficacy of a lure comprising a fish feeding system located in a separate enclosure. In some examples, a sound may be played to the fish before feeding, thereby training the fish to associate being fed with a sound. As such, the feeding sound may be used itself as a lure, once the fish associate the feeding sound with being fed. The lure arrangement 245a-c may be able to be selectively activated, to lure fish only when desired. For example, where the lure arrangement 245a-c is or comprises a light source, a user or a control system may be able to turn the light source on and off if desired. Where the lure arrangement 245a-c is or comprises a source of fish feed or a pocket of air, selective access may be able to be provided to the fish feed or pocket of air by containing the fish feed and/or air in a selectively accessible compartment, access to which is controlled by a user opening, for example, a door or hatch. The lure arrangement 245a-c may be able to be remotely activated by a user, for example by using wireless communication, or a wired electrical connection extending to the surface of the fish farm 200, or may be controllable by mechanical means, such as by pneumatic or hydraulic means actuated by valves, pumps etc. For example, an air pocket may be filled or replenished with air provided in a conduit by mechanical means, or a mechanical feeding device may be operated by provision of hydraulic fluid thereto. In some examples, each enclosure may comprise the same lure arrangement 245a-c or combination thereof (e.g. a combination of a light source and fish feed) or some or all of the enclosures 230,232,240 may comprise differing lure arrangements 245a-c.

In the example of Figure 2, the fish are held mainly in the first and third enclosure 230,232 – e.g. the fish may be held in the first and third enclosures 230, 232 in the long-term, or for a longer period of time, and may only be held in the second enclosure 240 for shorter periods of time, such as when it is desired to remove some or all the fish from the fish farm 200, or when there is a desire to starve only a portion of the fish in the fish farm. The second enclosure 240 is arranged above the first and third enclosure 230,232 and has a cuboidal shape, although it should be noted that other shapes may also be possible, such as a cylindrical shape, or any other shape that is desired by the user. The shape of the second enclosure 240 may be at least partially defined by the floating structure 204, as in this example the third enclosure 232 is contained therein, and in cases where a sliding bulkhead is used (as will be described in later sections), it may be beneficial having a shape with at least one uniform crosssection. In some examples, for example when the second enclosure 240 can be raised to a level above the waterline (e.g. by de-ballasting the support structure) then it may be beneficial to have a shape with a vertically reducing cross-sectional area, such as an inverted pyramid or cone, as this would facilitate crowding the fish towards a single point in the second enclosure for extraction therefrom.

As previously described, the second enclosure may be made from a flexible net structure that is supported by ropes or ties, or may be made from a collection of rigid net panels to form a rigid frame structure, with netting located in the frame openings. In some examples, the second enclosure 240 may be made from rigid panels (e.g. of steel or plastic) which may be water permeable, or in some examples the rigid panels may not be water permeable, in which case a water circulation system may be provided, for example through use of a fluid pump arrangement. The size of the second enclosure 240 relative to the floating structure 204 may permit the second enclosure 240 may be held below the water surface.

The first and third enclosure 230,232 in this example also comprise a cuboidal shape with a pyramidal lower section at their bottom part. However, in another example, the enclosures 230,232,240 may have another shape, such as that described in relation to Figure 1 (e.g. a cylindrical shape). Herein the second enclosure 240 is formed by a net structure, the net structure being connected with connectors such as ropes to the floating structure 101,102,103 to apply tension to the net structure and hold it in place/shape relative to the floating structure 204, although in some examples, the second enclosure 240 may be directly connected to the floating structure 101, 102, 103. Having a second enclosure may permit the fish farm 200 to be used to separate a portion (e.g. some) of the fish therein, for harvesting, without having to harvest all the fish therein at one time. This may enable the overall size of the fish farm to be increased, as there is no need to harvest all the fish at once and limit the farm to the number of fish which may be harvested on a single vessel. This also means that it is not necessary to starve all the fish in the first enclosure prior to extraction of only a portion of the fish.

Although illustrated is a location above the first enclosure 230 and the third enclosure 232, the second enclosure 240 may also be located to one side of the first enclosure, at the same height thereof. In some examples, the second enclosure, or at least part of the second enclosure may be located adjacent (e.g. at the side of) the first and/or third enclosure, and inside an outer enclosure 211, e.g. an outer net (illustrated in broken outline in Figure 2) which may be used as a barrier to stop the escape of a fish, should there be a breach in one of the enclosures (similar to the second net 111 illustrated in Figure 1).

In the example illustrated in the disclosure of Figure 2, fish are grown in the first and third enclosure 230,232. The second enclosure 240 may enable the selection of a number of fish from the first and second enclosure 230,232, for grouping the selected fish based on some characteristic thereof and optionally for removing said selected fish from the fish farm 100. In another example the arrangement of the enclosures 230,232,240 may differ, e.g. the enclosures may be arranged side by side or the function of the enclosures may differ.

Figure 3 illustrates the process of fish being lured into the second enclosure 240. Here, the access arrangement 250 is configured to an open position to permit fish access through at least one of the access units 251, 252 into the second enclosure 240. It may be beneficial to be able to open each of the access units 251, 252 individually, to permit selective access between the second enclosure 240 and either one or (if desired) both of the first and third enclosures 230, 232. In some examples, it may be beneficial to provide a sequential opening of the access units 251, 252, for example to move fish from the first enclosure 230 to the second enclosure 240, and then from the second enclosure 240 to the third enclosure 232.

The second enclosure 240 may be smaller than the first and third enclosures 230,232 as shown in this example, thereby enabling only some of the fish in the fish farm to move into the second enclosure 240, effectively selecting those fish from the fish held in the first and third enclosure 230,232. After a desired number of fish have been lured into the second enclosure 240, the access arrangement 250 may be closed such that it blocks the access through the access units 251,252 into the first and third enclosure 230,232, trapping the fish in the second enclosure 240. The fish in the second enclosure 240 may then be optionally starved and extracted from the fish farm 200, e.g. for slaughtering or for moving to another fish farm.

Figure 4 illustrates a step in a method of operating a fish farm 200. In the illustration of Figure 4, after luring the fish into the second compartment 240 as described in relation to Figure 3, access through the access arrangement 250 is restricted by a restrictor arrangement 260 to selectively restrict/permit access of fish between the second enclosure 240 and the first and third enclosure 230,232 (e.g. from the second enclosure 240 to the first or third enclosure 230, 232). The restrictor arrangement 260 may be configured to allow smaller fish to pass therethrough, for example by providing an opening or openings that are sized to allow only smaller fish to pass therethrough. In an example where fish of any size have been permitted into the second enclosure 240, using a restrictor arrangement 260 to permit only fish below a certain size from passing therethrough has the effect of trapping the larger fish in the second enclosure 240 as shown in Figure 4. This may be useful as it may permit a group of larger fish to be held in the second enclosure 240, for example for harvesting, while harvesting of fish that are too small is avoided.

The restrictor arrangement 260 may comprise multiple restrictor units 261,262 as shown in Figure 4, herein comprising a unit 261 at the access unit 251 and another unit 262 at the access unit 252. As shown, the restrictor arrangement 260 may be located inside the access arrangement 250. In another example, the restrictor arrangement 260 may be attached to the access arrangement 250 e.g. at an opening of the access arrangement or may be located separated from the access arrangement 250. The restrictor arrangement 260, more precisely the restrictor unit 261, is introduced in detail in Figures 5a-c.

The luring arrangement may be utilized to lure the smaller fish back into the first and third enclosure 230,232 by disabling the luring unit 245b and activating the luring units 245a,c, as well as to lure fish in to the second enclosure 240, or by changing from an attraction lure to a repulsion lure, thereby encouraging fish that have been lured into the second enclosure 240 to leave. As shown in Figure 4, then only the larger fish remain in the enclosure 240 enabling to select fish for extraction by size. This may be beneficial, when extracting only the largest fish from the fish farm 200 while leaving the smaller fish thereby permitting them further time to grow to a desired size before extraction. The described method may not only enable extraction without harming the fish, as the fish are not physically stressed or forced during the selection process, but also enables the selection of a desired group of fish to be extracted, i.e. the fish which have grown big enough, to prevent extraction of fish which may be too small for further sale/processing, or which may not be able to be sold for a high price.

Figures 5a-c show an access unit 251 of the access arrangement 250 and a restrictor unit 261 of the restrictor arrangement 260 in further detail. On the left side of each Figure, a sectional side view on the access unit 251 and the restrictor unit 161 is illustrated. On the right side of each Figure, an elevation view is provided. The restrictor unit 261 is arranged inside the access unit 251. The access arrangement 250 may comprise multiple access units 251 similar to that described, or only a single one. The restrictor arrangement 260 may comprise a restrictor unit 261 located in each access unit 251 of the access arrangement 250, or in some examples, the fish farm 200 may comprise an access arrangement 250 or access arrangements 250 that do not comprise a restrictor arrangement 260 for cases where access is required, but with no requirement for size restriction.

The access unit 251 illustrated comprises a first access port 255 and a second access port 256 in the example of Figures 5a-e. As described in reference to in Figures 2-4, the first access port 255 is located in the first enclosure 230 and the second access port 256 is located in the second enclosure 240. Here, the access unit 251 comprises a hollow shaft that connects the first access port 255 to the second access port 256, thereby connecting two enclosures between which the access unit 251 is located, such as the first and second enclosure 230,240. In some examples, the access unit 251 may be or comprise a pipe or a hose to connect the first and second enclosure 230,240, for example in situations where the first and second enclosures are not immediately adjacent.

The restrictor unit 261 comprises a plurality of restriction members, in this example in the form of rigid bars with spaces therebetween for permitting a fish to pass therethrough. In other examples, the restrictor unit 261 may comprise a single restriction member, and/or the restriction member or members may be in the form of a panel(s), plate(s) or bar(s). As shown in Figures 5a-e, the restrictor unit 261 comprises two sets of restriction members 264,265, a first set of restriction members 264 shown in an upper position in Figures 5a-e and a second set of restriction members 265 shown laterally offset from the first set of restriction members 264 in a lower position. The sets of restriction members 264,265 comprise spaces between the members to permit a fish to pass therethrough. In this example each of the members are the same size and are equally spaced. However, in some examples, the members may not be equally sized and/or may not have equal spacing, such that at least two of the spaces between each of the members may differ. The first set of restriction members 264 is slidably moveable relative to the second set of restriction members 265 between an open position and a closed position. To achieve this, either the first or the second set of restriction members 264, 265 may be moveable, or both sets of restriction members may be moveable. The open position is shown in Figure 5b, herein the first and second set of rigid bars 264,265 are axially aligned, such that the fish may pass through the space between the first and second set of restriction members 264,265. The closed position is shown in Figure 5a, in which the first set of restriction members 264 is aligned with the spaces of the second set of restriction members 265, thereby preventing passage of a fish therethrough. Shown in Figure 5c is a third configuration, in which the first set of restriction members 264 has a partial overlap with the second set of restriction members 265, thereby reducing the space available for passage of a fish therethrough. This third configuration may be used when selecting fish according to their size as described with reference to Figure 4 as a larger fish may be unable to swim through the passage while a smaller fish may be able to do so. In the case where the restriction members 264, 265 are in the form of plates, the plates may be oriented at an oblique angle relative to the direction of motion, which may assist to provide a partial overlap between the restriction members 264, 265 when a degree of size restriction is required.

In this example the restriction members within each set of restriction members 264, 265 are parallel to one another. Similarly the restriction members of the first and second set of restriction members 264,265 are parallel to one another. In another example the restriction members may be in a different configuration, e.g. each set of restriction members 264,265 may form a grid structure, rather than being elongate and parallelly disposed, or the restriction members may be positioned with the longitudinal axis of one set of restriction members 264 being oblique e.g. angularly displaced relative to the second set of restriction members 265. In this example the first set of restriction members 264 is slidably moveable relative to the second set of restriction members 265 in a direction perpendicular to the longitudinal axis of the restriction members e.g. such that motion of the first set of restriction members 264 is parallel to the motion of the second set of restriction members 265, such as motion located in parallel planes. In some examples, the first set of restriction members 264 may be moveable relative to the second set of restriction members 265 in a direction of the longitudinal axis of the restriction members or in both the direction of the longitudinal axis, and in a direction perpendicular to the longitudinal axis as previously described. The first and/or second set of restriction members 264 may be remotely moveable by a user or may be moveable by a control system controlling the operation of the fish farm 100. An actuator may be connected to either one or both of the first and/or second set of restriction members 264, 265 depending on which of the sets of restriction members are to be moved. The actuator may be in the form of a remotely (e.g. wirelessly) operated motor, or may comprise a mechanical connection to the surface, allowing a user to move the restriction members if necessary.

The access unit 251 and the restrictor unit 261 may be arranged in the vicinity of an air pocket structure 270, and in some cases the air pocket structure 270 may incorporate a structural engagement with the access unit 251 and/or restrictor unit 261. The air pocket structure may comprise an accumulation of air 271, to be held in a subsurface location, as illustrated by the location of the access units 251 in the Figures. The accumulation of air 271 is located in contact with the water 273 inside the first enclosure 230 via a water-air-interface 272. The fish may be able to see the water surface at the interface 272 and be lured to the accumulation of air 271 for example as they may feel the need to adjust their swim bladder. By luring the fish to the air pocket structure 270, the fish will then be located in the vicinity of the access unit 251, and some fish may swim through the access unit 251, without the yet the need to utilise the lure arrangement.

In another example the air pocket structure 270 may be considered to form part of the lure arrangement, and may enhance the efficacy of the lure arrangement in a separate enclosure by encouraging fish to swim towards access to another enclosure, thereby making the fish more likely to be attracted to the lure in another enclosure. The air pocket structure 270 may be a location that is frequently visited by fish. Therefore, if the air is removed from the air pocket structure 270, or if access to the air pocket structure 270 is blocked, the fish may still be likely to swim to the structure, and then may swim through the access unit 251 in search for an air pocket in an adjacent enclosure. In some examples, a one-way opening may be used, such as an opening with a flapper structure or funnel structure, to prevent fish from returning to the previous enclosure once having moved through the access unit 251.

Figures 5d and 5e illustrate an example of an air pocket structure 270 with a sliding panel 277 that may be placed either over the access arrangement 251 (Figure 5d) or over access to the air pocket structure 270 (Figure 5e), in this example by a simple sliding motion. As such, the fish may approach the air pocket structure 270 seeking access to the air pocket. With access to the air pocket blocked, the fish may swim through the access arrangement 251 instead.

The fish farm 200 may comprise a sensor arrangement for measuring the quantity of fish moving through the access arrangement 250. Herein the sensor arrangement comprises a sensor 269 configured to count the number of fish passing through the access unit 251. The sensor arrangement may comprise a sensor at each access unit 251,252 of the access arrangement 250, and thus the sensor arrangement may have a submerged location, as the sensor arrangement comprises a sensor at each access unit 251, 252 of the access arrangement 250. The sensor 269 may be a camera comprising image processor with a counter to count the number of fish passing through the access arrangement 250, and/or may comprise a photodetector and optionally a light source. In some examples, the sensor may provide information permitting a processing unit or a user to measure the size and biomass of each fish passing through the access arrangement 250 to calculate the number or mass of the fish currently passing through the access unit 251 or approaching the access unit 251 and for example, into the second enclosure 240. The sensor 269 or sensor arrangement may be or comprise an echo sounder for measuring the biomass of fish in the proximity of the sensor arrangement. Preferably the sensor arrangement, herein the sensor 269, is located adjacent at least one of the first and second access ports 255,256 thereby permitting the sensor arrangement to register each fish passing through the access arrangement 250. This may have the effect of reducing the measurement error when compared to methods that involve the observation (e.g. scanning) of large groups of fish in an enclosure, as the sensor arrangement is able to identify each fish as it passes through the access unit 251, and measure the mass of fish passing therethrough, thereby giving a better estimate of the biomass of fish in an enclosure. The efficacy of such a system may increase further when used in combination with the described fish farm 200 comprising at least a first and second enclosure, with the fish being lured from one enclosure to another, as the fish may pass more slowly and/or in a more organised manner than in fish farms that use other methods of moving fish such as physically forcing fish from one enclosure to the next. When fish are forced from one enclosure to the next, large numbers of fish may be pushed together, making counting of such fish difficult as well as estimating the biomass weight of the crowded fish. In the present disclosure, where the fish swim from one enclosure to the next to follow a lure, the fish may move more slowly through an access unit 251, thereby facilitating counting thereof, and additionally facilitating estimating biomass weight, identifying the ID and identifying the health condition of the fish.

The sensor data provided by the sensor arrangement 269 may be used by a user or a control system to provide control to the volume of biomass in each of the enclosures in the fish farm 200, for example in the second enclosure 240. In one example, the sensor arrangement 269 may provide an indication of the biomass in an enclosure, such as the second enclosure 240, such that a control system or a user may be able to operate a restrictor unit 261 or restrictor units accordingly. This may permit a biomass of fish, or a desired number of fish, to be contained within the second enclosure that is the same as the capacity of a vessel for removing the fish from the second enclosure.

In some examples, a combination of counting, and estimating the average biomass or weight of each fish passing by the sensor arrangement 269 may be used to calculate the biomass in an enclosure, which may be a quicker or computationally less demanding method of calculating the biomass. In a further example, the weight of each fish may be registered with a view to providing a statistical representation of the size of each fish that is being sensed by the sensor arrangement 269. In the case that too many fish that are being sensed by the sensor arrangement 269 are of an undesirable size and/or weight (e.g. are too small) then the restrictor unit 261 may be configured to prevent further access of fish into an enclosure, or the operation of the lure arrangement 245 may be changed in order to try to encourage movement of fish of a desired size/weight into the desired enclosure. In cases where the sensor arrangement 269 is capable of monitoring the health condition of a fish (e.g. where the sensor arrangement comprises a camera and health identification criteria), then the sensor arrangement 269 may be used to ensure that only fish of a superior health class are permitted entry into an enclosure (e.g. the second enclosure 240).Figure 6 shows a top view on the fish farm 200 of Figures 2-4, the fish farm 200 comprises a number of enclosures, in this example a first enclosure 230, a third, fourth and fifth enclosure 236,237,238 and a second enclosure 240 located above the other enclosures 230,236,237,238. The respective enclosures are connected to the second enclosure via the access arrangement 250 and the restrictor arrangement 260 comprising four access units 251-254 each with a respective restrictor units (not shown). Also shown are air pocket structures 270a-d, which may be integrated into the access units 251-254, as illustrated. The air pocket structures 270a-d and the access arrangement 250 and restrictor arrangement 260 may be connected to the floating structure 101,102,103. As illustrated, the second enclosure 240 is located towards the centre of the fish farm 200, which may assist to protect fish in the second enclosure 240 from predators, or harsh sea conditions, and ensure that there can be access to the second enclosure 240 from each of the first, third, fourth and fifth enclosures 230, 236, 237, 238. It should be noted that, although the second enclosure 240 is illustrated as a single enclosure, it may be possible to have multiple sub-enclosures in place of one single second enclosure 240, or have the second enclosure 240 be formed of multiple parts where each part is an individual enclosure. The parts of the second enclosure 240 may be located above the first, third, fourth and fifth enclosures 236, 237, 238. In this case, there may be access arrangements positioned between each of the parts comprising the second enclosure 240, to enable a fish to move between each of the parts of the second enclosure 240 when necessary.

Figure 7 shows a side view of the fish farm 200 and in which the fish are being crowded in the second enclosure 240, which may be in addition to the method as previously described. When a desired number of fish has moved into the second enclosure 240, the access arrangement 250 and the restrictor arrangement 260 may be used to restrict at least some fish from moving back to the first and third enclosure 230,232, for example restrict the fish based on their size, as previously described. The second enclosure 240 may comprise a volume restriction device 280 for selectively reducing the volume of space available to a fish therein, thereby crowding the fish in the second enclosure 240 and facilitating extraction therefrom.

Figures 8-14 show an example of a volume restriction device 280 and component parts thereof which may be installed in the second enclosure 240. The volume restriction device 280 in this example is a sliding bulkhead 282. The second enclosure 240 comprises a first engagement profile 284, in this example comprising an elongate engagement member, and the sliding bulkhead 282 being installed in the second enclosure 240 comprises a receiving profile 285 forming the counterpart to the engagement profile 284, the receiving profile 285 being in the form of a recess in the bulkhead 282. The profiles 284, 285 are configured to fit together and enable a sliding movement of the sliding bulkhead 282 through the second enclosure 240. The sliding bulkhead 282 may comprise a net material. In some examples, the volume restriction device 280 may comprise a net or a wall, may be rigid or flexible, and may be permeable to water, while restricting movement of a fish. In some examples, the volume restriction device may be installed in any or all of the enclosures, e.g. the first, second or third enclosure 230,232,240. The first profile 284 may comprise multiple elongate members arranged in (e.g. along a wall of) the second enclosure 241 forming a rail for the second profile 285 to slide along as shown for example in Figure 9. The engagement profile 284 may comprise a male connector part being connected to and extending from the wall of the second enclosure 241 being interlockable with a female connector part of the receiving profile 285 as is shown in Figures 10-12. In other examples, the engagement profile 284 may be the female profile, while the receiving profile 285 is the male profile.

Figure 13 shows the volume restriction device 280 from a side perspective with a wall of the second enclosure 241 shown. The volume restriction device 280, herein the sliding bulkhead 282, may be connected to the wall of the second enclosure 241 by multiple interlocking profiles 284,285 as is illustrated. Preferably, the receiving profile 285 is large enough compared to the size of a single member of the engagement profile 284 so that it cannot disengage or fall off the guiding engagement profile 284 as shown in Figure 14. The sliding bulkhead may have only small openings towards the walls of the second enclosure 241 to prevent fish from passing through the openings and moving to the other side of the sliding bulkhead 282. In some examples, the sliding bulkhead 282 may comprise brushes installed along an edge thereof, at the interface between the bulkhead 282 and the second enclosure, to close any gaps between the bulkhead 282 and the walls of the second enclosure 240, thereby assisting to prevent a fish entering the gap between the bulkhead 282 and the second enclosure 240. Although not illustrated, lines may be attached to the sliding bulkhead 282 to facilitate movement of the sliding bulkhead. The lines may be connected to winches, which may be located on the floating structure 204, for example. Other means of movement may also be possible, such has having a rack and pinion engagement between the sliding bulkhead and the enclosure, using hydraulic cylinders or a worm gear to move the bulkhead.

In cases where the sliding bulkhead is not in use, or is not needed to crowd the fish, the sliding bulkhead may be positioned within the second enclosure 240 in order to form a partition in the second enclosure 240, thereby effectively separating it into two sub-enclosures. The bulkhead may be installed in this position as a temporary measure, or over a longer period of time.

In other cases, the sliding bulkhead may be able to be temporarily installed in an enclosure, such as the second enclosure 240. For example, where it is known that fish are to be crowded in the second enclosure (e.g. because fish are required to be moved from the second enclosure 240) then the sliding bulkhead may be temporarily installed in the second enclosure 240. This has the further advantage that the sliding bulkhead may be uninstalled for repairs or cleaning more easily.

Figures 15-17 show another application of the fish farm 200 according to the invention. In Figure 15 all fish in the fish farm 200 are located inside the first enclosure 230. However, the first enclosure 230 may require cleaning, repair/replacement of parts of an enclosure, or for another reason the fish might need to be moved to the third enclosure 232. The fish may be lured from the first enclosure 230 to the second enclosure 240 by opening the access unit 251 and restrictor unit 261 and activating the luring unit 245b as shown in Figure 16. When the desired number of fish are inside the second enclosure 240 (which may be all or some of the fish), the access unit 251 and restrictor unit 261 are configured to prevent access between the first and second enclosure 230,240. The access unit 252 and restrictor unit 262 are opened to enable the fish to swim into the third enclosure 232. The luring unit 245b of the second enclosure is deactivated and the luring unit 245c inside the third enclosure 232 is activated to lure the fish thereto. Figure 17 shows all the fish having arrived at the third enclosure 232. The access unit 252 and restrictor unit 262 may now be closed to keep the fish in the third enclosure 232. It should be noted that, while the luring unit 245b is illustrated as being located on the side wall of each enclosure in Figures 15 to 17, it may alternatively be located in any other appropriate location, such as on the floating structure 204.

Figures 18 and 19 show different options for extracting the fish from the fish farm 200 once a desired number of fish has been moved into the second enclosure 240. The second enclosure 240 is then able to be separated from the other enclosures 230,232 by closing the access arrangement 250 and the restrictor arrangement 260 and decoupling the second enclosure 240 from the remainder of the fish farm. In this example, the second enclosure 240 may be coupled to the fish farm 200 by a releasable fastening arrangement such as ties or releasable locks. Then the fish may be extracted from the fish farm by releasing the connection of the second enclosure 240 to the fish farm 200 and removing the second enclosure 240, e.g. by transporting the second enclosure to a nearby vessel. The net of the second enclosure 240 may be installed after extracting the fish therefrom or another net may replace the removed one, forming another second enclosure 240 at the fish farm 200 to enable further operation according to the disclosed methods. In another case the fish may be extracted by a suction pipe or hose 287, a suction device, an ROV, a robotic fishing arm or the like as shown in Figure 19, leading directly to a storage container on a vessel. In this example, the suction hose 287 is illustrated as being part of the fish farm 200, however in other examples the suction hose 287 may be provided on a vessel. Fish may be transported to the vessel (e.g. via the hose) and removed from the fish farm 200.

Figures 20 and 21 show methods of crowding the fish prior to extracting the fish from the fish farm 200. In operation of the fish farm, the enclosures 230,232,240 are preferably below the water surface which may reduce the impact of waves, predators and parasites such as sea lice on the fish population. The enclosures 230,232,240 may for example be five meters or more below the water surface. The enclosures 230,232,240 may be suspended from the floating structure or the floating structure may be itself below the water surface as shown in the illustrated examples. The floating structure, the enclosures 230,232,240 or both may comprise means to selectively alter the buoyancy, enabling to move any of them to the water surface, e.g. for crowding the fish, facilitating construction or facilitating maintenance and cleaning.

In Figure 20 the access units 251,152 and restrictor units 261,262 comprise extendible or flexible connections between the access ports 255,256 at the respective compartments 230,232,240 as introduced in Figures 5a-c. Utilizing the flexible connections, the second enclosure 240 may be moved towards the water surface, e.g. by lifting the second enclosure 240 with a hoist or other appropriate lifting device. Upon reaching the water surface, the fish are then able to be crowded between the water surface and the lower end of the second enclosure 240 as illustrated in Figure 20.

Figure 21 shows an example, wherein the whole fish farm 200 is moved towards the water surface by changing its buoyancy, e.g. utilizing pumps to pump ballast water out of the floating structure. Consequently, the second enclosure 240 is close to the water surface and similar to Figure 20 the fish will crowd between the water surface and the lower end of the second enclosure 240.

As seen in some examples, the fish farm of this disclosure is not limited to a single or two enclosures 230,232,240, but the person skilled in the art will understand to apply the inventive principle to fish farms of various sizes, structures and net arrangements.

Figure 22 illustrates an additional example of a fish farm 300, or part thereof. In this example, the fish farm 300 comprises a first enclosure 330 and a second enclosure 340 in common with previous disclosures. In contrast with the previous examples, here the entire of the first and second enclosures 330, 340 are contained entirely beneath the waterline 390, both being suspended by a floating structure 304, which in this example is in the form of a plurality of floating buoys connected to the first and second enclosures 330, 340 via mooring lines 358.

As in previous examples, the first and second enclosures 330, 340 may comprise nets, for example nets supported by frames, or may comprise panel members that are affixed together to form the first and second enclosures 330, 340, and which may be permeable to water. As in previous examples, the second enclosure 340 is located above the first enclosure 330, with the second enclosure 340 also being smaller than the first enclosure 330 in this example. Again, in common with previous examples there is an access arrangement 350, which may comprise a restrictor arrangement, and selectively enable fish to move from the first to the second enclosure 330, 340, and vice versa if desired. Here, the first enclosure 330 is directly connected to the second enclosure 340 directly, and the two are separated by a top net 306. Here, there is a lure arrangement 345a in the first enclosure and a lure arrangement in the second enclosure 345b which may be used to attract or repel a fish to/from each enclosure 330, 340.

Although not illustrated in Figure 22, in this example the fish farm 300 may comprise a floating collar, which may be positioned at the top of the second enclosure 340, or at the top of the structure comprising the enclosures in the case that the second enclosure is not positioned at the top of the enclosure structure. The floating collar may be able to be ballasted and deballasted, which may be useful if there is a requirement to bring the enclosures 330, 340 to the waterline 390 (for example for removing the second enclosure 340), or to lower the enclosures 330, 340 further below the waterline 390, for example to provide additional protection against sea lice, waves, surface predators, etc..

As in previous examples, the first and second enclosures 330, 340 may comprise vertically oriented nets or permeable panel structures to divide the first and second enclosures 330, 340 into sub-enclosures.

The described fish farm 300 has a much simpler floating structure 304 as compared to other fish farms. As such, this fish farm 300 may be cheaper and quicker to construct and maintain than a fish farm 300 having a more complex structure 304.

The same fish farm 300 is illustrated in Figure 23, however in this example rather than being suspended from a floating structure 304 on the waterline 390. Instead, in this example the enclosures 330, 340 are suspended from below, for example from the seabed, on a cable 392. The cable 392 may be connected to a winch which may enable the fish farm 300 to be raised and lowered in the surrounding fluid. As in the previous example although also not illustrated, a floating collar may be positioned at the top of the second enclosure 340 (e.g. at the top surface) or at the top of the enclosure structure in the case that the second enclosure 340 is not located at the top of the structure. In Figure 24 is illustrated a further example of a fish farm 400. In this example there is a first and a second enclosure 430, 440, with the second enclosure 440 being located above the first enclosure 430, as in previous examples. Also similar to previous examples, an access arrangement 450 is positioned between the first and second enclosure 430, 440, with the first enclosure being directly connected to the second enclosure. In this example, the lure arrangement is in the form of a lure 445a in the first enclosure 430 and a lure 445b in the second enclosure 440.

Here, one of the first or the second enclosure 430, 440 is connected to a buoyancy structure 404 (illustrated the second enclosure 440 is connected) which floats on the water surface 490. As in previous examples, a top net 406 separates the first enclosure 430 from the second enclosure 440. In this example the top net 406 may be moveable, so as to vary the volume of space available in the first and second enclosures 430, 440. This may be useful to facilitate crowding of fish in either enclosure 430, 440, and may also enable the fish to be kept deeper in water if necessary, which may assist in avoiding sea lice or adverse weather/wave conditions. The top net 406 may be connected to a frame, which may assist to hold the top net 406 in a rigid configuration. The top net 406 may then be suspended from the buoyancy structure 404 by wires, which may be connected to a hoist arrangement for raising and lowering the top net 406. Alternatively, the top net 406 may comprise a rack and pinion style engagement with the first and second enclosures 430, 440, which may enable movement of the top net 406 relative thereto. In some examples, the top net may comprise a small motorised arrangement or hydraulic arrangement that may enable a user to move the top net 406 relative to the first and second enclosures 430, 440.

In some examples, rather than raising/lowering the top net 406, the entire enclosure structure may be raised and lowered 430, 440. As such, there may be a section of loose net (e.g. net that is not supported by a frame) along the length of the enclosure structure (e.g. adjacent the floating structure 404) that may be able to be expanded or contracted as needed. In this example, winches may be provided on the buoyancy structure 404 and cables may extend along the length of the enclosure structure in order to enable raising and lowering thereof.

Figures 25 to 28 will now be considered in the following paragraphs.

Recent years have seen a considerable growth in the fish farming industry in various countries, and it is projected that fish farming will continue to play a key role in the provision of food in the future. A continual focus on safety, fish welfare and the environmental impacts of fish farming, however, drives a demand for improved methods and solutions for fish farming.

Various such improvements have been suggested over the recent years.

For conventional fish farming, there exists several types of fish pens, but the most common technology for salmon farming is to use a floating flexible collar with a suspended net. The fish pens are often moored in a grid mooring system. A nearby feed barge may be used for providing the required support systems for the fish pens.

Due to the continuous increasing demand for sea food and the limited number of sheltered locations suitable for fish farming, there is a need to develop new solutions that can, for example, be used outside these sheltered areas, where environmental influence may be more severe, or which provide advantages in relation to production efficiency, fish welfare, or other parameters.

The spread of illnesses, infections or parasites may be harmful not only to the fish in a fish farm, but also to the humans who are consuming contaminated fish. Therefore, often the examination of dead fish, so called mort, is a regulatory requirement. Offering possibilities to examine the dead fish or even being able to examine living fish is of great advantage for a fish farm, especially when the process may be carried out remotely, partly automatically or even fully automatically. This disclosure aims at providing an apparatus for offering stated advantages.

Referring to Figure 25, a fish farm 2100 comprises a frame, which preferably comprises at least one column 2101, at least one pontoon 2102 and at least one truss structure 2103. Additionally, the frame may comprise corner elements 2104. The structure of the frame is not limiting this disclosure and as fish farms 2100 are widely known, the person skilled in the art may pick a design for a fish farm 2100 he deems suitable for his needs.

The fish farm 2100 is located in a body of water having a water level 2111. Preferably, the floating fish farm 2100 is located on the sea, more preferably, the fish farm 2100 is located offshore.

The fish farm 2100 comprises a fish enclosure 2105. The fish farm 2100 comprises a fish examination system, which comprises a fish retrieval arrangement 2004. The fish retrieval arrangement 2004 is attached to the fish enclosure 2105. The fish enclosure 2105 typically comprises at least one net, preferably with a conical section (e.g. a net cone) at the bottom as shown in Figure 25. The fish enclosure 2105 may be a fish cage to keep the fish therein. The fish retrieval arrangement 2004 comprises a fish collection unit 2001 to collect fish from the fish enclosure 2105 and fish transport means 2002, 2003 to transport the fish from the collection unit 2001 to a buffer arrangement 2010, which is located in an examination room 2099.

Preferably the examination room 2099 is located above water level 2111. The examination room 2099 may comprise a single or multiple rooms and may be on the fish farm 2100, on land, on another vessel or distributed amongst any of these if it comprises multiple rooms.

The fish collection unit 2001 is preferably placed at the lowest point in the net structure as dead fish and sedated/stunned fish typically tend to sink and therefore will naturally move towards that point, however it may be placed at any point deemed to be useful by the person skilled in the art. The fish collection unit 2001 may have any shape suitable for leading fish into the fish collection unit 2001, e.g. a hole to let fish pass through it or funnel-shaped, the fish collection unit 2001 then resembling a hopper. The fish collection unit 2001 may be placed inside the bottom of the net cone as shown in Figure 25. Alternatively, the fish collection unit 2001 may be integrated into the net, e.g. with an opening in the net, for example the fish collection unit 2001 as shown in Figure 26. In some examples, a double net system may be used. If a double net system is used, the fish collection unit 2001 may preferably be arranged at the inner net, the outer net functioning as an additional escape prevention mechanism in case of damage to the fish collection unit 2001 or the inner net. As the fish collection unit 2001 typically has some weight to maintain its position in the fish enclosure 2105 and to prevent damage to the fish enclosure 2105 by shearing forces, the fish enclosure 2105 is preferably reinforced in the vicinity of the fish collection unit 2001.

The fish transport means 2002, 2003 may comprise a flexible hose 2002, a rigid piping 2003 or any combination of the two. Preferably, the rigid piping 2003 is used where the fish transport means 2002,2003 may be attached to the fish farm 2100 and the flexible hose 2002 is used to connect to rigid piping 2003 to the fish collection unit 2001 to preserve the flexibility of the fish enclosure 2105. Fish transport means 2002, 2003 are widely known and typically use a water flow through a hose or pipe to transport the fish. The water flow may be created by e.g. pumps, ejectors, vacuum chambers or gas lift systems. The fish transport means 2002, 2003 may be arranged inside the fish enclosure 2105 or outside of the fish enclosure 2105 or a combination of both as shown in Figures 25 and 26. Before the fish reaches the buffer arrangement 2010, the fish may be separated from the transport medium, e.g. by using a dewatering unit 2005 as shown in Figures 27 and 28. The dewatering unit 2005 may be in the form of a platform having an inclined surface relative to the horizontal with openings therein to allow water to pass through the surface of the platform. In such examples, the openings are too small to permit passage of a fish therethrough, and as such said fish moves (e.g. slides or is moved/propelled) along the surface of the dewatering unit 2005. The transport medium (herein water) may then be drained from the dewatering unit 2005 and reused or discharged, e.g. discharged back to sea in case of the transport medium being water.

Other types of fish retrieval arrangements 2004 may also be used, e.g. picking up by a remotely operated vehicle (ROV), actuated brushes, elevator systems or the like. The person skilled in the art is expected to be able to select a fish retrieval arrangement 2004 compatible with the structure of the fish farm 2100 and suitable for retrieving the desired amount of fish from the fish enclosure 2105 and caring for the health status of the fish. In cases where the fish being collected are already deceased, or are to be euthanized, the fish retrieval arrangement 2004 may be required to handle the fish such that a subsequent biopsy or examination is able to be carried out on the fish. As such, the requirements of this fish retrieval arrangement 2004 may differ from another system, for example one in which the fish are intended to be retrieved and transported live from one location to another.

The fish retrieval arrangement 2004 may also consist of several sub-systems of these types.

The fish are transported to the buffer arrangement 2010 by the fish retrieval arrangement 2004 as shown in Figure 28. Optionally, the dewatering unit 2005 separates the fish and the transport medium, which is herein water. As the fish retrieval arrangement 2004 may supply the buffer arrangement 2010 with fish in bursts or batches, the buffer arrangement 2010 is designed to buffer, i.e. store the fish for a short amount of time, until the fish will be picked up one after another by a transport arrangement 2020 for further usage.

The transport arrangement 2020 transports each fish individually from the buffer arrangement 2010 and towards an exit port 2080. The exit port may be or comprise an exit station, such as a container or further conveyor belt. In some examples, the dewatering unit 2005 and optionally the buffer arrangement 2010 may be positioned relatively lower than the rest of the transport arrangement 2020, or at least lower than some parts of the transport arrangement 2020, which may facilitate the draining and returning of water back to the sea. In some examples, the dewatering unit 2005 is arranged slightly above water level to reduce the distance the water and fish have to be moved upwards and to facilitate draining and returning of the water back to the sea. The transport arrangement 2020 may comprise a grabber, conveyor, lifting basket, or the like to select a fish from the buffer arrangement 2010 and move that fish from to the transport arrangement 2020. Having grabber, conveyor, lifting basket, or the like that is able to grab one single fish and move said fish to the transport arrangement 2020 may assist to reduce the likelihood of the transport arrangement 2020 being blocked as a result of multiple fish being placed thereon. However, in some examples, an arrangement may exist (e.g. a grabber, conveyor, basket, etc.) that is able to select and move multiple fish, should the user desire this or should the fish examination system be configured for receiving and processing multiple fish simultaneously. The fish examination system comprises at least one examination station 2030,2040,2050, the transport arrangement 2020 being configured to transport a fish or some fish to at least one of the at least one examination stations 2030,2040,2050.

Alternatively, the transport arrangement 2020 may transport the fish in batches, transporting as many fish as may be suitable for handling by the at least one examination stations 2030,2040,2050. Whether one or several fish are transported at one time to the at least one examination station 2030, 2040, 2050 may be selected by the user.

Preferably, the transport arrangement 2020 is configured to transport the fish to each of the at least one examination stations 2030, 2040, 2050. The at least one examination station 2030,2040,2050 may each have at least one substation to conduct related examinations and/or tasks and the transport arrangement 2020 may be configured to transport the fish to any of these. The transport arrangement 2020 may use a metering means 2021, e.g. a hatch, an opening, a revolving door, a robotic arm, grabber, conveyor, lifting basket or the like, to transport the fish one after another, or in batches with a controllable number of fish, out of the buffer arrangement 2010.

The transport arrangement 2020 may transport the fish passively, e.g. using gravity, water slides or the like in combination with opening and closing sluices, or actively by a controlled conveyor system 2022 or by a combination of both. The controlled conveyor system 2022 may comprise e.g. a belt conveyor, a roller conveyor, horizontal displacement actuators, vertical lifting actuators, robotic arms, etc.

The fish may be transported directly by/on the conveyor system 2022 or in an object such as a box, a bag, a crate, a cage or the like.

The transport arrangement 2020 may comprise means to rotate/flip the fish or its transport object so that all sides of the fish can be examined. A passive system may flip the fish while it is moving by using ramps or the like, while an active system may actively rotate the fish, e.g. using flipping surfaces or grabbing means. Alternatively or additionally, the at least one examination stations 2030, 2040, 2050 may comprise means to rotate the fish or its transport object.

The transport arrangement 2020 may be split in multiple parallel paths or may split into or may merge multiple parallel paths to improve the capacity of the fish examination system. For example, some stations may take longer to carry out their tasks than others, herein multiple of the slower stations may be deployed, with the transport arrangement 2020 delivering the fish to any of the multiple slower stations which is currently not occupied to circumvent the bottleneck. Before or after the slower stations the paths of the transport arrangement 2020 may split or merge to adjust to the number of possible paths to the number of next stations. Or the transport arrangement 2020 may have various routes for fish, for example different routes for fish having different examination results. Some fish may be sent to the exit port 2080 directly, whereas others may have to undergo further and/or deeper examinations. As such, there may exist different paths to enable the fish to be transported accordingly.

The transport arrangement 2020 and the buffer arrangement 2010 are considered part of a fish providing arrangement, the fish providing arrangement providing the fish to the stations of the fish examination system, e.g. the examination stations 2030,2040,2050, the exit port 2080 or a storage system as will be introduced in more detail below. In some examples, the fish providing arrangement may comprise either of the buffer arrangement 2010 and the transport arrangement 2020, e.g. there may be only one examination station 2030,2040,2050 and the buffer arrangement 2010 directly provides fish to the one examination station 2030,2040,2050 or the fish is transported from the fish retrieval arrangement 2004 to the at least one examination station 2030,2040,2050 without buffering the fish. In some examples, the fish retrieval arrangement 2004 may comprise a designated buffering system to buffer the fish, e.g. by retrieving only one fish at a time from the fish farm 2100 with the fish transport means 2002,2003, in this case there may be no buffering unit 2010 present. In some examples, the fish retrieval arrangement 2004 may provide the fish directly to the at least one examination station 2030,2040,2050, with also no transport arrangement 2020 being present. In some examples, there may be no providing arrangement, e.g. the fish may be provided by an operator or a remotely controlled vehicle to the at least one examination station 2030,2040,2050 or the fish retrieval arrangement 2004 buffers the fish and transports the fish to the at least one examination station 2030,2040,2050.

In some examples, the fish examination system may not be connected to a fish retrieval arrangement 2004 retrieving fish from a fish farm 2100, but may receive fish by other means, e.g. the fish may be provided in containers to the fish examination system, e.g. by depleting the fish from the container into the buffer arrangement 2010, by using the transport arrangement 2020 to move the fish out of the container to the fish examination system or by directly providing the fish from the container to the examination stations 2030,2040,2050.

The fish examination system comprises at least one examination station 2030, 2040, 2050 to conduct examinations of the fish. Not all of the illustrated examination stations 2030, 2040, 2050 may be required in every case. For example, the fish examination system may be modular, and not all of the various examination stations 2030, 2040, 2050 may be required in every example. For example, one of the examination stations 2030, 2040, 2050 may be replaced by another arrangement depending on the tests that are required by the user, which may include official authorities or a fish farmer. The purpose of the at least one examination station 2030,2040,2050 may be to examine the fish and acquiring any information desired by the fish farmer, advantageously satisfying any regulatory requirements related to fish and especially mort examination. The fish may be examined in a way to identify symptoms of known diseases, damages, deformities, parasites, poisoning or the like. Alternatively or additionally, the fish may be investigated to evaluate production parameters such as e.g. size, meat colour, fat content, omega 3 content, etc. Additionally, the number of fish entering the fish examination system may be determined to be able to calculate a morbidity and/or mortality rate.

The transport arrangement 2020 transports the fish to an initial check station 2030, wherein at least one first non-invasive check is conducted. The initial check station 2030 may comprise multiple sub-stations 2031, 2032, 2034 conducting the same or advantageously different checks. The check results of each sub-station are gathered and the examination data may be stored and/or processed.

The initial check station 2030 may comprise at least one scale 2031 to weigh the fish. Additionally or alternatively, the initial check station 2030 may comprise at least one camera station 2032 comprising at least one camera 2033a,b,c to take photos of each fish. The photos may be taken from different angles using multiple cameras, a moving camera or by moving the fish. The photos may be examined manually or by computerized image processing. A grid/ruler may be integrated on the conveyor system 2022 surface or the camera to determine the length, height and/or width of the fish, and against which the fish may be photographed to provide accurate information to a user. Alternatively, the length may be determined using laser measurements, a calliper or the like. Additionally or alternatively, the initial check station 2030 may comprise means for X-ray imaging to check the bone structure, hyperspectral imaging to check contamination, 3D scanning, ultrasonic probing, IR imaging and/or electrical conductivity measurements to find deformities or anomalies. Additionally or alternatively, the initial check station 2030 may comprise motion detection means, e.g. a camera or measurements using electrical stimulation. The initial check station 2030 may take many measurements (e.g. may be programmed to take many measurements) of a single fish, which may be able to be decided by a user. The measurements taken by the initial check station 2030 may be able to be stored in a suitable location, such as digitally in a database, for reference by a user.

Fish may be equipped with systems for individual fish monitoring such as a simple ID mark attached to the fish, a transmitter inside the fish or any other tag or instrumentation of individual fish. Such tags and sensors should be identified and/or removed from the fish before the fish may be examined and/or ground and ensilaged, to read the tag/sensor, to register the tagged/instrumented examination data of the fish, to register the fish as dead if applicable, to reuse the tag/sensor and to avoid non-biological content in the ensilage. The required system to identify tags/sensors depends on the type of tags/sensors used, for example a metal detector or and RFID scanner, etc. The initial check station 2030 may comprise a tag scanner 2034, which herein is a metal detector.

Alternatively or additionally, each fish may be identified using optical recognition such as facial recognition, or recognition of some other distinguishing feature of each fish. Therefore, the fish may be monitored with cameras while inside the fish enclosure 2105 and a profile may be created and stored in a database to provide identification details for each fish. Using the cameras of the initial check station 2030 and face recognition software having access to the database of the fish profiles, the individual fish may be identified, enabling an identification of the fish without needing to tag the fish with any markers/tags.

To investigate parameters that cannot be detected from non-invasive examinations, it may be required to take biopsy samples of the fish, e.g. tissue samples, blood samples, etc. The fish examination system may be equipped with an autonomous, semi-autonomous or remotely operated sample station 2040 for collecting and storing samples. Samples should preferably be taken from dead fish only, therefore the initial check station 2030 may be configured to obtain and provide information about whether the fish is alive or dead. The samples may be extracted from all fish, randomly selected fish, a selection based on the examination results of the initial check station 2030, manual selection or a combination of any of these. Samples may be extracted and put into a sample tube 2041, the sample tube 2041 may be stored in a storage container 2042 with a suitable medium. In one example the sample tubes 2041 have an integrated cutting mechanism and require an actuator 2043, e.g. robotic arm or similar means, to be used upon the fish, such that a biopsy sample is able to be taken from a fish using the sample tube 2041 alone (e.g. without the need to provide a separate cutting tool). The storage container 2042 may be configured to be handled by a robotic device, such as a robotic arm, as is illustrated. The robotic device that is handling the storage container 2042 may have a storage compartment with multiple storage devices therein 2042, and into which a storage device or multiple storage devices 2042 may be held after use. In such examples, the robotic device may be able to take many samples from a fish in quick succession, without having to move to place a used storage device 2042 e.g. in a holder, and/or without having to retrieve a new storage device 2042. Such a robotic device may be considered to have a magazine-style compartment in which storage devices 2042 may be stored. In another embodiment, the biopsy sample may have to be cut from the fish using a cutting tool to cut the biopsy sample from the fish and collected into the sample tube 2041. The actuator 2043 may be guided using cameras or other sensors to take the sample at the desired location. The actuator 2043 may be controlled remotely by an operator, who is conducting the biopsy of the fish using the sample station 2040. Alternatively, the transport arrangement 2020 may comprise positioning means that are suitable for positioning the fish underneath the sample tube 2041 such that the actuator 2043 may be required to provide only a vertical movement of the sample tube 2041. Alternatively, the actuator 2043 may comprise means to extract samples from different angles, e.g. by comprising a robotic arm, a joint or a rotational actuator.

The fish examination system may comprise a selection station 2045, wherein each fish is considered and optionally selected for autopsy. The fish may each be considered independently and may be selected based upon user input, the examination results of the initial check station 2030, the examination results of the sample station 2040, a predetermined pattern (e.g. every second, third, fourth, fifth, or the like, fish may be selected) or randomness. The selected fish may then be moved to an autopsy station 2050, either by the transport arrangement 2020, which will split in multiple paths, or by the selection station 2045, if the selection station 2045 comprises its own actuators 2046 to move the fish to the autopsy station 2050 as shown in Figure 27. The selection station 2045 may comprise a device for moving a fish to the autopsy station 2050, which may be the actuator or actuators 2046. The actuator or actuators 2046 may be a pushing device (e.g. an extendable rod or bar) or a grabbing or lifting mechanism, which functions to physically push the fish to the autopsy station 2050. Alternatively either or both of the transport arrangement 2020 and the selection station 2045 may comprise hatches, trapdoors or other means to select individual fish, e.g. for autopsy, which may then be moved to the autopsy station 2050. Alternatively, the autopsy station 2050 may comprise means to move the fish from the transport arrangement 2020 to the autopsy station 2050.

The autopsy station 2050 may be used for more advanced sample extraction, e.g. to precisely take samples of specific organs or of specific locations. The autopsy station 2050 may be used for a general autopsy to look for internal damages, etc. Additionally, the autopsy station 2050 may be used to remove objects, for example tags and sensors from the fish.

The autopsy station 2050 may comprise at least one robotic arm 2051, which may be controlled remotely, operate autonomously or operate in a combination of both. The at least one robotic arm 2051 may be equipped with one or more permanent and/or exchangeable tool such as cutting tools as e.g. knives, water cutting tools, laser cutting tools, saws, scissors, nippers, etc., manipulation tools as e.g. spatulas, tweezers, grabbers, etc., cleaning tools as e.g. air blower, water jet or a vacuum cleaner, etc., sensor tools as e.g. light, cameras, etc. or other tools as sampling tools, tools for injection of liquids or gasses in flesh or cavities. Additionally, the autopsy station 2050 may comprise cameras and other instrumentation to provide guidance for the operator or a control system of the autopsy station.

The obtained autopsy samples or the rest of the fish may be stored for future analysis, depending on specimen and/or desired future analysis method the person skilled in the art will select a fitting storing method, e.g. freezing or cooling in a freezer or refrigerator or using a chemical solution as e.g. formalin, alcohol or a Bouin solution or drying the sample for storage. Preferably, the samples will be labelled e.g. by putting them in labelled containers or bags. More preferably, the sensors and tags possibly removed by the autopsy will also be stored and/or reused.

The fish examination system may therefore comprise a freezer 2060, which may be a container held at a freezing temperature into which the autopsy samples or the rest of the fish are then stored for future analysis. For example, when any of the examination stations 2030,2040,2050 has downtime, the freezer 2060 may store the fish until the examination stations 2030,2040,2050 are back online to proceed with the examination of the fish. The transport arrangement 2020 may comprise one or multiple actuators 2061 to move the fish to the freezer 2060. In other examples the transport arrangement 2020 may use a conveyor belt or robotic arm to move the fish into the freezer 2060. In another example, the at least one robotic arm 2051 of the autopsy station 2050 may move the fish into the freezer 2060.

After investigation by the initial check station 2030, optionally the sample station 2040 and further optionally the autopsy station 2050, the transport arrangement 2020 may transport the fish to an exit port 2080. The exit port 2080 may e.g. lead to storing means to store the fish, to further transport means to transport the fish or to a grinding and ensilaging unit. The storage means may be or comprise a freezer, which may be used to store a fish for future analysis. The exit port 2080 may comprise selection means for selectively freezing or grinding/ensilaging a fish. The selection means may be or comprise a moveable section of conveyor which may selectively place a fish into either a freezer or a grinder/ensilaging unit. Although not shown, the exit port 2080 may therefore lead to two separate locations in some examples. In other examples, only one or other of a freezer or grinding/ensilaging unit may be present. Grinding and ensilaging units are known and widely used and may for example comprise: a grinder for grinding of fish, a mixing system for mixing grinded fish with formic acid, a measurement system for measuring the pH number of the ensilage and adjust the dosing of acid with the mixing system, storage tanks for storing the ensilage wherein the storage tanks comprise agitators to stir the ensilage, further measurement systems and mixing systems for monitoring and adjusting pH number if required, a pumping system for the ensilage from the storage tanks.

The fish examination system of this example additionally comprises a control system, wherein the control system is designed to coordinate and synchronize the execution of the tasks of the other systems 2004,2010,2020 and stations 2030,2040,2045,2050 of the fish examination system. In particular, the control system may coordinate the movement of the fish, which may be carried out by the fish retrieval system 2004 and the transport arrangement 2020, and the examination and/or selection processes of the stations 2030,2040,2045,2050 in order to prevent jams. The control system may handle the start and stop of the fish examination system. The start signal may be given by a human operator, may be given by sensor readings, preferably inside the fish enclosure 2105, e.g. a camera detecting fish movement in the fish collection unit 2001, or may be based on regular or random time intervals (e.g. each day). In case of manned operation, the control system may give the human operator advice on when to start the fish examination system. To stop the fish examination system, the control system may be given a stop signal by a human operator, by sensor readings or by regular predetermined or random time intervals (e.g.5 minutes). Preferably, the control system runs the fish examination system for a predetermined period of time after receiving the start signal and checks whether at least one fish has entered the fish examination system in the given time period. If no fish have entered the fish examination system in the predetermined time period, the control system may understand this as the stop signal, or as being equivalent to a stop signal provided by a user. If at least one fish entered the fish examination system in the predetermined time period, the control system may then continue operation for another predetermined time period, and check whether fish have entered the fish examination system during this other predetermined time period. The control system may then continue operation until such a time as no new fish enter the fish examination system in a predetermined time period. It may be possible to vary the length of the predetermined time periods, e.g. to increase the check frequency if the initial set time is fairly large, or alternatively to decrease the check frequency.

The control system may detect whether the fish examination system shall be started or stopped by sensors inside the fish collection unit 2001, e.g. cameras, motion sensors, touch sensors, etc., or may use any sensors of the other systems 2004,2010,2020 and stations 2030,2040,2045,2050 to check if a fish is currently under examination by the fish examination system. Preferably, each system and station is equipped with at least one sensor, whose sensor output is accessible by the control system, to enable the control system to determine where fish in the system are and coordinate the fish transportation and the examination and sorting processes as well as the start and stop of the fish examination system. Alternatively or additionally, the control system may take into account the storage capacity of the buffer arrangement 2010, running the fish retrieval system 2004 if there is both space in the buffer arrangement 2010 and there are fish in the fish collection unit 2001 and not running the fish retrieval system 2004 if any of these conditions is not fulfilled. The control system may then run the transport arrangement 2020 and all of the stations 2030,2040,2045,2050 until there are no more fish in the buffer arrangement 2010 and the last fish has finished examination and has exited the fish examination system through the exit port 2080 or has been stored for future investigation.

As the time it takes each of the stations 2030,2040,2045,2050 to carry out their individual tasks may vary, the control system preferably adjusts the rates at which the fish arrive at the individual stations 2030,2040,2045,2050 to prevent jams and ensure a steady flow of fish in the fish examination system. As previously mentioned, it may be possible that at least one of the stations 2030,2040,2045,2050 is duplicated or is visited multiple times per fish, with the transport arrangement 2020 connecting these in multiple possible routes for the fish between the buffer arrangement 2010 and the exit port 2080. Herein the control system may control the transport arrangement 2020 to deliver the fish to the desired station, out of the selection of the stations 2030,2040,2045,2050, preferably to a station that is currently not yet occupied if there are multiple stations of these type of station present. The control system may also increase or decrease the dosing frequency and/or the transport speed of the transport arrangement 2020 to ensure a steady flow of fish in the fish examination system.

Additionally, the control system may be designed to count the number of fish that are examined by the fish examination system. Counting the number may be important to derive a fraction of infected or dead fish or to derive a statistic for the status, e.g. healthiness, size, weight, etc., of the fish, which the control system may also be designed for. Counting may be achieved by an optical sensor, for example an optical sensor positioned at any one of the aforementioned stations 2030,2040,2045,2050.

The control system may be equipped with software to process and analyse the examination data from the initial check station 2030, e.g. with image processing means to recognize possible cause of death, injuries, defects, symptoms of known diseases, parasites like sea lice or size, age, weight or other health conditions.

The control system may autonomously analyse the examination data and decide whether/which additional test or tests should be conducted, i.e. use the transport arrangement 2020 to transport the fish to the respective examination stations 2030,2040,2050 and use said respective examination stations 2030,2040,2050 to conduct the selected additional tests. The control system may autonomously analyse the examination data and decide to store fish for later examination or to consult a human specialist for analysis. Alternatively, the control system may randomly select fish for additional tests, storage or human examination not taking into account the examination data or use a combination of analysation results and chance.

In case of manned or remote operation, the control system may provide decision support to the human operator. The control system may propose alternatives for possible cause of death to the operator based on the examination data, may give warnings in case of symptoms for diseases, injuries or defects, may give recommendations and guiding for where to store samples, e.g. in which specific slot of the storage container 2042 to store biopsy samples (e.g. tissue samples), or give recommendations on the storage of fish. As such, the control system may comprise a communication means, for example a screen, for indicating such information to a user and may comprise input means, for example a keyboard or a mouse, to receive input from the operator.

Alternatively or additionally, the control system may store the examination data, any sensor data, the data comprising the examination result and the data of its start and stop signals. The control system may process these data and create reports or statistics and may save the reports to a storage and/or visualize the reports to a human operator on a screen or communication means. The control system may save the raw data to a storage and let another system/program/human do the data analysis.

The control system may also comprise a database storage of fish sample data. The control system may compare the fish sample data with the fish examination data to be able to identify whether the fish shows signs of diseases, deformities, deficiencies or the like. The control system may use the identification of diseases, deformities, deficiencies, or the like, to guide operation of the other systems 2004,2010,2020 and stations 2030,2040,2045,2050 of the fish examination system and/or to provide a human operator with an indication of the decision of the control system. The decision of the health status of the fish may be provided to the user for information purposes, or to enable the user to confirm the health status of a fish, for example where it is desired to highlight a particular health status to a user, or where the control system lacks sufficient certainty in the decision. The control system may also comprise a list of commands for various health statuses of the fish for the other systems 2004,2010,2020 and stations 2030,2040,2045,2050 of the fish examination system to be able to drive the other systems 2004,2010,2020 and stations 2030,2040,2045,2050 of the fish examination system according to the decision on the health status of the fish.

The control system may comprise several sub-systems each designed for another single or multiple of the described tasks.

The fish retrieval arrangement 2004 of the fish examination system may be suitable for collecting alive and dead fish and therefore both alive and dead fish may be transported to the examination stations 2030,2040,2050. The examination of live fish may yield relevant results, for example results relating to the fish growth in the fish farm 2100. Live fish should not undergo biopsy (i.e. sampling), autopsy and grinding as intended for dead fish, and therefore in cases where live fish may be retrieved by the fish retrieval arrangement 2004 the control system may be configured to identify whether a fish is alive or deceased. If the fish retrieval arrangement 2004 retrieves a live fish, a suitable action may be taken based on the fact that the fish is living. For example, the fish may be freed immediately, the fish may be measured in length and weight, non-invasive examinations may be performed on the fish or the fish may be euthanized in an appropriate manner and to enable further properties to be examined. For example, the fish may be alive, but infected with a virus, bacteria and/or parasite, and further examination of said fish may be necessary.

In the case of a live fish management system (i.e. a system configured to retrieve live fish), the system may check whether each live fish is capable of surviving on its own in the open sea or if the fish is alive but carries a disease, has injuries, defects or parasites. If the fish is capable of surviving on its own in the open sea and is healthy, the fish may be released to the open sea. If the fish is healthy but may not live in the open sea (e.g. due to local wildlife protection regulations), then the fish may be sent back into the fish enclosure 2105. If the fish has any diseases, injuries, defects or parasites, the fish may be euthanized prior to further examination and/or disposal (e.g. by grinding). Alternatively, a healthy fish may be euthanized and examined to gather information on the properties of alive fish in the fish enclosure 2105. The live fish management system may be in communication with, and use the check results from, the initial check station 2030 to identify whether the fish is alive or deceased. Alternatively, the live fish management system may comprise its own detection means, e.g. cameras, motion detection, electrical conductivity etc., to determine if the fish is alive or deceased and may comprise its own processing unit for determining what should next happen to the fish.

Alternatively, a human operator may receive information provided by the live fish management system and make a decision regarding what should happen to the fish based on the provided data. Live fish may also be stored in live fish holding tanks comprising a life support system (e.g. a system ensuring habitable conditions for the fish in the holding tanks, such as sufficiently oxygenated water, an acceptable temperature, etc.) to store the live fish for short periods of time to allow a human operator to then manually handle them at an appropriate time. In an alternative example, all fish retrieved by the live fish management system may be euthanized, and in such examples there may be no mechanism by which the fish are returned to the fish farm, or to the open sea. The live fish management system may be installed after the initial examination station 2030 (i.e. such that the live fish management system receives fish from the initial examination station 2030). In such examples, the live fish management system may be in communication with the initial examination station 2030 to enable usage of the initial examination data by the live fish management system. Alternatively, the live fish management system may be installed sequentially before the initial examination station 2030, and may be configured to conduct an independent test to check whether the fish is alive or deceased or, may be configured to perform a euthanization process on each fish without testing whether the fish is alive or deceased. The live fish management system may be installed at the fish retrieval arrangement 2004 to directly receive fish therefrom. In some examples, at least part of the live fish management system may be installed at the fish collection unit 2001. For example the live management system may comprise a transport means such as a suction tube for transportation of a fish directly to the live fish management system.

There are several methods of euthanizing the fish, depending on what are recommended and allowable methods in the country/region in which the fish farm 2100 is located, these recommended and allowable methods may of course change over time. The fish may be sedated/stunned prior to being euthanized, e.g. by using a chemical bath or injection, low temperature, a CO2 bath, application of a swift physical force, administration of drugs, electrocution, or the like. One or more of the methods of sedation may be used in combination, e.g. a chemical bath prior to applying a swift physical force.

After sedating/stunning the fish, the fish may be euthanized swiftly, for example by cutting gills or arteries. In other cases it may be acceptable to perform grinding of the fish and thereby killing the fish after the fish has been sufficiently sedated/stunned.

In the case of handling weakened fish, i.e. mostly weak, sick or injured fish, inside the fish enclosure 2105, the fish examination system may comprise additional means inside the fish enclosure 2105 to sedate/stun the weakened fish. These means may be a remotely operated vehicle, at least one sedation station inside the fish enclosure 2105, which is able to detect and sedate weakened fish or the like (e.g. by an camera that is able to recognise characteristics of a weakened fish and take action, such as alerting a user, or retrieving or sequestering the weakened fish by automated means). The at least one sedation station may also comprise the cameras used for individual fish facial recognition. After sedating/stunning the weakened fish, the sedated weakened fish may then sink to the bottom of the fish enclosure 2105 and for retrieval by the fish retrieval arrangement 2004 ultimately getting the treatment from the fish examination system and the live fish management system. The at least one sedation station may use injection of a chemical or drug, stunning by electrocution or application of a swift physical force or may apply a sedative in the surrounding water or through feed.

The at least one sedation station may alternatively or additionally comprise means to not only sedate but additionally or alternatively euthanize the fish, thereby also resulting in the fish sinking to the bottom of the fish enclosure 2105 and being retrieved by the fish retrieval arrangement 2004.

Should the fish be sedated but not euthanized, a live fish management system may also be installed as living fish should be treated differently to those that are deceased (for example, it may not be possible to take a biopsy or perform an internal examination of a living fish). In cases where the at least one sedation station is additionally required to euthanize the fish, then no live fish management system may be necessary.

The fish examination system may comprise a storage system to store fish after examination and/or biopsy and/or autopsy for future analysis thereof. The storage system may be used to store the whole fish. The storage system may function as a buffer system in case there is downtime of the examination stations 2030,2040,2050 and/or in the case that a main depository for fish (e.g. an ensilaging unit) is full. Euthanization of fish prior to storage may assist to provide a system that is more efficiently able to store the fish than if the fish were attempted to be stored alive. Live fish that are desired to be examined may be stored in live fish holding tanks comprising life support means. The fish may be marked or tagged before storage, such that there is traceability between stored fish, reason for storage and examination data and pictures of the stored fish. The fish may be tagged directly or the fish may be placed in a container, e.g. a plastic bag or box or a compartment, which may then be tagged. If the fish already has been tagged, the already existing tag may be used.

For long term storage of fish for future examination, a storage system configured to preserve deceased fish may be used, e.g. a deep freezer or a chemical bath such as alcohol or formalin. For short term storage of fish for future examination other methods may additionally be appropriate, e.g. an ice bath, super-chilling, a refrigerated storage or a storage tank without chilling. Such a storage system may be located below sea level in order to more easily achieve lower temperatures than may be achieved above sea level – for example because sea water may more easily be accessible for use as a coolant fluid.

Storage may be required, for example, during downtime of the examination stations 2030, 2040, 2050. Preferably, a storage tank comprises a refrigeration and ventilation system.

The storage system may be connected at various points to the transport arrangement 2020 of the fish examination system, for easy access thereof. For example, the storage system may be connected to the transport arrangement 2020 both before the initial check station 2030 and before the exit port 2080. Alternatively, the storage system may be connected after the exit port 2080. Alternatively, the storage system may be connected to the buffer arrangement 2010 enabling fish to be stored directly from the buffering unit 2010. Any appropriate connection between the storage system and the transport arrangement 2020 may be used.

The storage system may comprise a system for emptying the storage, for example an automated system for emptying the storage. The storage system may be emptied, for example, to transport the fish to another location.

The floating fish farm 2100 may comprise a cleaning and disinfection system to avoid unhealthy conditions, avoid spread of diseases and maintain a good working environment for service and inspection personnel. Cleaning and disinfection may be a manual task, may be done by an external system, or may be integrated in the fish examination system. An integrated cleaning and disinfection system may operate autonomously, e.g. based on algorithms considering the number of examined fish, the days since last cleaning, sensor readings, suspicion of contagious diseases, etc., at fixed time intervals, e.g. once a day or once a week, after each operation of the fish examination system, or based on the decision from a human operator. The cleaning and disinfection system may therefore comprise a central processing unit, configured to control e.g. the intensity and frequency of cleaning and disinfection of the fish farm 2100. The central processing unit may be capable of monitoring, for example, the time between cleans, and/or may be in contact with a network of sensors positioned on the fish farm 2100 and configured to measure the purity of water therein, or the volume of deposits of dirt, silt, detritus, or the like from the fish farm 2100. The control system may then be able to decide whether the fish farm 2100 should be cleaned or not.

Typically cleaning refers to the process of removing soils, particles and germs, while disinfecting typically refers to killing germs (e.g. bacteria and virus). The fish examination system may comprise only a cleaning system, only a disinfection system or both of them. There may be separate cleaning and disinfection systems or combinations, wherein typical cleaning methods include: rinsing, brushing ,degreasing, using soap, high pressure cleaning steam and air flow and typical disinfection methods include: using acid, alcohol or other chemicals e.g. hydrogen peroxide or hypochlorite, applying high temperature or ultraviolet light. If the fish examination system is formed by temperature resistant equipment, the whole examination room 2099 or all rooms belonging to the examination room 2099 of the fish examination system may be disinfected by raising the temperature, e.g. by using steam.

Preferably, cleaning and disinfection agents (if used) should be harmless or have minimal impact on the fish, on other marine life and on humans. The cleaning and disinfection system may be equipped with a system for collection of drain water, i.e. cleaning fluids, its storage and/or its discharge to sea. If chemicals are used, the drain water may be neutralized before discharge, diluted before discharge, discharged at a distance from the fish or a combination. There may also be separate systems, so that dangerous chemicals can be kept at an isolated circulation.

The fish examination system may also comprise a condition monitoring system, which will monitor the operation and function of the fish examination system, detect failures and may check whether any rooms of the examination room 2099 are free from humans before e.g. cleaning and disinfection starts. The condition monitoring system may be connected to the control system, may be part of the control system or vice versa, both may exchange any data or they may be independent systems. The condition monitoring system may comprise at least one CCTV camera at various places inside the at least one room of the examination room 2099 of the fish examination system, e.g. at the outlet of the fish retrieval arrangement 2004, at the transport arrangement 2020, at the buffer arrangement 2010, at the exit port 2080, at various drains, etc. The condition monitoring system may comprise at least one of an air temperature sensor, a temperature sensor on any of the systems 2004,2010,2020 and stations 2030,2040,2045,2050, a thermal camera to monitor the at least one room of the examination room 2099 of the fish examination system and the systems 2004,2010,2020 and stations 2030,2040,2045,2050, a vibration sensor, a humidity sensor, a pressure sensor, a gas detection sensor, a pH sensor e.g. mounted at a drain to monitor drain water, a motion detection sensor, a weighing cell to estimate the amount of fish in the system and detect clogging. The condition monitoring system may comprise motion detection means, image processing means, the manual use of CCTV or the usage of thermal cameras to detect fish falling off the fish examination system. The condition monitoring system may store surveillance data, create reports and/or statistics and may transmit its results and/or raw data to a user interface or an external data storage.

Herein a floating fish farm 2100 has been used for the depicted embodiments, however, the person skilled in the art will understand that this principle is also applicable to fish farms in a pond, lake, any artificial water compartment for fish farming or the like.

Some examples and aspects will now be described in the following numbered, non-limiting, clauses:

CLAUSE B1. A fish examination system for a fish farm 2100, the fish examination system comprising:

a fish retrieval arrangement 2004 for retrieving a fish from an external location and providing the fish to the fish examination system;

at least one examination station comprising a primary check station 2030 for conducting at least one non-invasive examination of a fish;

an exit port 2080 for receiving a fish from the primary check station 2030;

CLAUSE B2. The fish examination system according to clause B1, wherein the at least one examination station additionally comprises a sample station 2040 for extracting a physical sample from the fish and optionally performing an internal examination of a fish.

CLAUSE B3. The fish examination system according to clause B1 or B2, wherein the fish examination system comprises a fish positioning system comprising at least one of:

a buffer arrangement 2010 for temporary storage of a fish,

a transport arrangement 2020 for moving a fish in the fish examination system.

CLAUSE B4. The fish examination system according to clause B3, wherein operation of the fish positioning system is conditional on the examination data stored by the control system.

CLAUSE B5. The fish examination system according to any preceding clause, wherein the control system is configured to count the number of fish retrieved by the fish retrieval arrangement 2004.

CLAUSE B6. The fish examination system according to any preceding clause, wherein the control system is configured to compare the examination data with a database of fish sample data.

CLAUSE B7. The fish examination system according to any preceding clause, wherein the at least one examination station additionally comprises an autopsy station 2050 comprising a robotic autopsy device 2051 for performing an autopsy on the selected fish.

CLAUSE B8. The fish examination system according to clause B7, wherein the robotic autopsy device 2051 is a robotic arm.

CLAUSE B9. The fish examination system according to clause B7 or B8, wherein the autopsy station 2050 comprises:

a selection station 2045, wherein each fish is considered and optionally selected for autopsy;

CLAUSE B10. The fish examination system according to any preceding clause, wherein the exit port 2080 is or comprises a grinding and ensilaging system.

CLAUSE B11. The fish examination system according to any preceding clause, wherein the fish examination system comprises a freezer 2060 or a storage arrangement to store the fish for future examination.

CLAUSE B12. The fish examination system according to any preceding clause, wherein the sample station 2040 comprises a storage container 2042 to store extracted samples.

CLAUSE B13. The fish examination system according to any preceding clause, wherein the fish providing system, the at least one fish examination station and the exit port 2080 are arranged in an examination room 2099.

CLAUSE B14. The fish examination system according to clause B13, wherein the examination room 2099 is located on a fish farm 2100.

CLAUSE B15. The fish examination system according to any preceding clause, wherein the fish examination system comprises a cleaning and disinfection system.

CLAUSE B16. The fish examination system according to any preceding clause, wherein the control system is configured to autonomously conduct the examination process of the fish examination system.

CLAUSE B17. The fish examination system according to any preceding clause, wherein the external location is a fish farm.

CLAUSE B18. A method for examining the health status of a fish, the method comprising: retrieving a fish from a fish farm 2100;

providing the retrieved fish at an examination station;

CLAUSE B19. The method of clause B18, wherein the method comprises extracting a sample from the fish.

CLAUSE B20. The method of clause B18 or B19, comprising conducting the method autonomously.

CLAUSE B21. The method of any of clauses B18 to B20, comprising using data stored in the control system to assist in conducting the method autonomously.

CLAUSE B22. The method of any of clauses B18 to B21, wherein the method comprises grinding and ensilaging the fish at the exit port.

CLAUSE B23. The method of any of clauses B18 to B22, wherein the method comprises providing the retrieved fish at an examination system for conducting an autopsy of the fish.

Figures 29 to 34 will now be considered in the following paragraphs.

For a variety of reasons, some fish in fish farms may become injured, diseased, or may grow otherwise malformed. So called loser fish or weakened fish may be desirably extracted from the fish farm 3100 to prevent further suffering of the fish, before they infect other fish, or before they become deceased and expose the remaining fish in the fish farm to bacterial disease. Some fish may be extracted for examination to determine the health status of fish, and this procedure may be performed on both healthy and unhealthy fish, for example a random selection of fish. This disclosure aims at providing an apparatus to facilitate extraction of fish from a fish farm, preferably to automatically extract faint fish from the fish farm and enable selective extraction of such fish.

Figure 29 shows a fish farm 3100 schematically illustrated in a sectional view. The fish farm 3100 comprises a frame, the frame comprising at least one pontoon structure 3102 and at least one column structure 3101. Additionally, the fish farm comprises a fish enclosure 3105 wherein at least a portion or all of the fish in the fish farm 3100 are located, stretching further to the bottom and right of the drawing and two boundary lines of which being indicated by dashed lines. The fish enclosure 3105 is located below the water surface 3111 and may comprise a lid or cover 3005 to keep the fish below the water surface 3111, the cover 3005 being indicated with dashed lines. The cover 3005 can be of a net material or any other material. The fish enclosure 3105 comprises a net structure being permeable to water, but additionally with some degree of flexibility and toughness. In some examples, the fish enclosure 3105 may be a rigid enclosure, while in others it may be a flexible enclosure or may be a combination of both. In some examples, the fish enclosure 3105 may extend above the water surface 3111. The fish enclosure 3105 may be a fish cage or net to keep the fish therein.

Some fish may need to adjust their swim bladder regularly, e.g. physostomes, and may therefore swim to accumulations of breathable air, such as air pockets. A fish may be able to detect the location of such accumulations, as the amount of oxygen in the water is higher closer to these accumulations, or because the fish may be able to see the surface of the water at the boundary with the air, particularly if there is a light located at or near the surface of the water. It is known that weakened fish may be more attracted to and may cluster at the accumulations of air, for example as these fish may feel the need for adjusting their swim bladders more often, or because these fish may benefit from the increased levels of dissolved oxygen in the water near to these air accumulations. As such, a volume of breathable air may be used as a lure, particularly a lure for weakened fish which may be more attracted to this lure than fish that are well. In some cases, the fish may habitually return to a pocket of air in the fish farm 3100, for example because they need to adjust their swim bladders regularly (e.g. every day, every week etc). Therefore, the fish may naturally move towards the air pocket, and therefore this part of the fish farm may have a predictably number of fish therein, which may facilitate extraction of the fish in this location. Installing a fish extraction system 3000 which uses these insights to lure and collect the fish may facilitate the extraction and removal of weakened fish in particular, or may enable to extract any randomly selected healthy fish for examination. It is also known that some species of fish have a natural tendency to swim against a flow of water, and as such flows of water may be established within a fish farm, also with the purpose of luring a fish to a specific location.

The fish farm 3100 comprises a fish extraction system 3000 for luring fish thereto. The fish extraction system 3000 may permit a fish to enter the fish extraction system 3000, but prevent said fish from exiting the fish extraction system 3000. As such the fish extraction system 3000 may effectively trap a fish therein to enable extraction of the trapped fish. The fish extraction system 3000 comprises a separation compartment 3001 into which a fish may swim, or may be lured. The separation compartment 3001 may be selectively accessible from the fish farm 3100, and may lead to an extraction compartment 3031 where fish may be collected for later extraction. The separation compartment 3001 is intended to permit fish to gather close to the extraction compartment 3031, preferably luring a selection of fish, e.g. weakened fish, close to the extraction compartment 3031 to facilitate to lure or force the fish into the extraction compartment 3031. The fish extraction system 3000 may comprise means to extract the fish from the extraction compartment 3031, e.g. a hatch or an opening to provide access to the extraction compartment 3031, a collection and transport unit as a robotic arm, a conveyor system or the like.

The separation compartment 3001 is illustrated as extending vertically from the fish enclosure 3150 to an extraction compartment 3031 that is located above the water surface 3111. However, in other examples, the separation compartment 3001 may extend diagonally from the fish enclosure towards the water surface 3111 (e.g. at an oblique angle relative to the water surface 3111) where there may be located the extraction compartment 3031. In some examples, the separation compartment may extend in a horizontal direction from the fish enclosure 3105. The extraction compartment 3031 may be located above or below the water surface 3111. In cases where the extraction compartment 3031 is located below the water surface 3111, then there may be an access shaft or other access arrangement to enable access thereto.

The separation compartment 3001 may be flexible or, preferably, have solid walls. The separation compartment 3001 may be arranged inside the fish enclosure 3105, and in some examples may be partially defined by the fish enclosure 3105, and/or by the fish farm 3100. The separation compartment 3001 may be attached to, or form part of, the frame of the fish farm 3100, and may comprise an access port 3003 by which to access the separation compartment 3001. The access port 3003 may comprise a restriction arrangement 3004, e.g. a door, moveable panel or cover, that may be selectively moved by a user (e.g. by a remote actuation means) in order to selectively provide access to the separation compartment 3001. In this example, the restriction arrangement 3004 comprises a moveable cover. The access port 3003 may simply be an aperture or entry to a recess in a wall of the fish enclosure 3105, or it may comprise a section of pipe or tubing to connect the separation compartment 3001 to the fish enclosure 3105. The restriction arrangement 3004 may be permeable to water, and may only obstruct movement of a fish. In some other examples, the restriction arrangement 3004 may be impermeable to water, and may provide a seal at the access port 3003, permitting further flow of water therethrough when the restriction arrangement 3004 is restricting access to a fish through the access port 3003.

Although not illustrated in detail, the restriction arrangement 3004 may comprise a sizegrading system. The size grading system may be the form of a plurality of bars that cover the access port 3003. The bars may be selectively spaced apart to permit only fish of a desired size to pass through, thereby preventing larger fish from swimming through. In some examples, the spacing between the bars may be adjustable by a user, thereby allowing the user to choose the size of fish that swim through the restriction arrangement 3004. In some examples, the user may initially permit fish of all sizes to swim through the restriction arrangement, before adjusting the size grading system to permit only smaller fish to return to the fish farm 3100, thereby enabling only larger fish to be held in the extraction compartment 3031 if this is desired. Where only smaller fish are desired to be held in the extraction compartment 3031, the user may simply adjust the size grading system to permit only smaller fish to pass therethrough.

In some examples, the access port 3003 may be considered to selectively isolate the separation compartment 3001 from the fish enclosure 3105, particularly in cases where the separation compartment 3001 is at least partially defined by the fish enclosure 3105. The separation compartment 3001 may be part of any column 3101 or pontoon 3102 structure and may be part of multiple of the column 3101 and pontoon 3102 structures. The compartment 3001 may also be attached to any of the column 3101 and pontoon 3102 structures. As shown in Figure 29, the separation compartment 3001 is partially located in the pontoon structure 3102 and partially located in the column structure 3101, and may be defined by either or both of these structures 3101, 3102.

In addition to the separation compartment 3001, the fish farm 3100 also comprises an extraction compartment 3031. In this example, the extraction compartment 3031 is defined by the column 3101. The extraction compartment 3031 may be useable to extract fish from the fish farm 3100, more precisely from the fish enclosure 3105. Although the column structure 3101 illustrates the compartments 3001,3031 therein as having a vertical column structure, in some other examples, the compartments 3001,3031 therein may extend diagonally through the column structure 3101. In another example the compartments 3001,3031 may be arranged to extend in a horizontal direction.

The extraction compartment 3031 is accessible via the separation compartment 3001. In the example of Figure 29, the extraction compartment 3031 and the separation compartment 3001 are connected via a connection port 3020. The connection port 3020 may comprise a fish trap so as to permit a fish to travel from the separation compartment 3001 to the extraction compartment 3031 but not in reverse, for example the connection port 3020 may permit a fish to travel in only one direction therethrough, thereby preventing a fish from re-entering the separation compartment 3001 once the fish has entered the extraction compartment 3031. The fish trap may be in the shape of a flexible sleeve, held open at one end, thereby enabling a fish to swim through easily in one direction, or a hinged door that opens only in one direction.

Although not illustrated, there may be other fish traps located in the separation compartment 3001 (e.g. at the access port 3003) or in the extraction compartment 3020.

In this example, a part of the extraction compartment 3031 is located above the sea level 3111 enabling extraction and handling of the fish above sea level 3111, as well as permitting access to an air source 3011 from the extraction compartment 3031, which may function as a lure, as previously described. In some examples, the air source 3011 may be an arrangement to bubble oxygen through the water, e.g. by bubbling oxygen into the water using pipes or having pipes with openings to dissolve oxygen in the water. In some examples pure oxygen may be bubbled through the water, in other examples, multiple gases or a combination of gases and fluids may be bubbled into the water, e.g. air. It should be noted that in some other examples, the air source 3011 (e.g. the accumulation of breathable air) may be an air pocket of air that is artificially provided, or it may be naturally occurring air from the atmosphere. The extraction compartment 3031 may comprise a vent or air inlet/outlet for permitting air to enter and exit the extraction compartment 3031.

The extraction compartment 3031 may comprise an extraction port 3010 to permit a user access to the extraction compartment 3031, and which may also permit a flow of air into and out of the extraction compartment 3031. In another example, the extraction port 3010 may permit automatic extraction and collection by an extraction and collection arrangement, e.g. comprising robotic arms to take the fish out of the water and collect it in a container, allowing further treatment like examination or transportation outside the extraction compartment 3031.

The extraction compartment 3031 may comprise an air source 3011 (herein an accumulation of air) for luring. In another example, the extraction compartment 3031 may be completely filled with water and the air source 3011 may comprise means to enrich the water with oxygen, e.g. tubing pumping oxygen into the water. In another example, there may be no air source 3011, but the fish may be lured into the extraction compartment 3031 by a supply of feed. In some examples, the extraction compartment 3031 may comprise a flow of water therethrough. The flow of water through the extraction compartment 3031 may be constant, or may be selectively operable such that it is only present when fish are able to access the extraction compartment 3031. As such, the extraction compartment 3031 may comprise a fluid pump for pumping a fluid from the extraction compartment 3031 to the fish enclosure 3105, via the access port 3003. The pump may be located in the extraction compartment 3031, or may be located separate to the extraction compartment 3031, or may be fluidly connected to the extraction compartment 3031 by a fluid conduit, or the like. In addition to providing a flow of fluid, the pump may assist to provide the extraction compartment 3031 with a flow of oxygenated water (e.g. of a higher oxygenation than the water present in the extraction compartment 3031). A fish or fish may reside in the extraction compartment 3031 for a considerable length of time (e.g. several hours or days) and therefore it may be important to ensure that conditions in the extraction compartment 3031 are habitable e.g. are sufficiently supplied with oxygenated water. The pump may provide water of a desired temperature to the extraction compartment 3031 to ensure that the compartment remains habitable (e.g. within a desirable temperature range, free from ice, etc.). Water pumped into the extraction compartment 3031 may be taken from the surrounding environment, or may be taken from a supply tank of water, which may have been treated, for example).

In addition, the extraction compartment may require to be kept habitable for a fish thereon. For example ,the extraction compartment may comprise a supply of oxygen, e.g. in the form of oxygen being bubbled through the water, which may assist to increase the volume of dissolved oxygen in the water, and may additionally assist to remove dissolved carbon dioxide from the water, which may be harmful to the fish in large quantities. The water may also comprise a filter, such as an ammonia filter and which may be a mechanical and/or biological filter, in order to filter ammonia from the water and may comprise a UV light source which may be used to kill bacteria or other pathogens that reside therein, thereby increasing the habitability of the extraction compartment 3031. Additionally or alternatively, water that is pumped into the extraction compartment 3031 may be treated by exposure to UV light prior or oxygen to entry into the extraction compartment 3031, thereby ensuring that fewer pathogens are introduced into the extraction compartment 3031 with the provided water.

Shown in Figure 30, the fish farm 3100 comprises an air pocket structure 3034. In normal usage, the air pocket structure 3034 may comprise an air pocket 3032, and may form a part of the fish enclosure 3105. The volume in the air pocket structure 3034, which is not occupied by the air pocket 3032, is preferably filled with water. The fish in the fish enclosure 3105 may have access to the air pocket 3032 in the air pocket structure 3034, and may use the air in the air pocket 3032 to fill their swim bladders, for example. The air pocket structure 3034 comprises an entry port 3033 which in this case is defined by the fish enclosure 3105. The entry port 3033 enables fish to swim from the fish enclosure 3105 to the air pocket structure 3034 and vice versa. The entry port 3033 may be an aperture, an opening or a removed wall of the air pocket structure 3034 as shown in Figure 30. The entry port 3033 may comprise a pipe or tubing, intermediate tanks, sections with a larger cross-section or may directly connect the air pocket structure 3034 to the fish enclosure 3105 as shown in Figure 30. Additionally, the entry port 3033 may comprise apertures or other restriction device or devices to control the rate at which fish may pass through the entry port 3033. In some examples, the air pocket structure 3034 may be completely submerged and may be arranged close to the fish enclosure 3105 wherein the fish are farmed. Thereby the distance for the fish to travel to the air pocket structure 3034 is lowered and the lure potential of the air pocket structure 3034 may be increased. The submerged air pocket also means that the fish enclosure 3105 may be completely submerged in the fish farm 3000, which may permit the fish to be located further below the surface, thereby providing benefits in terms of reduced sea lice infestations, and protecting the fish from the impact of adverse weather/wave conditions. Having a submerged air pocket structure 3034 requires a compartment with side-walls and a top wall which are non-permeable to air.

The air pocket structure 3034 is arranged such that the entry port 3033 enabling access from the air pocket structure 3034 to the fish enclosure 3105 and vice versa is in the vicinity of the access port 3003 connecting the fish enclosure 3105 to the separation compartment 3001. This may assist fish to be lured to an air pocket 3032 in the air pocket structure 3034 and then into the separation compartment 3001. Therefore, the access port 3003 may be strategically located in the fish enclosure 3105 (e.g. strategically located near to an existing air pocket) so as to encourage fish, in particular weakened fish, to swim nearby thereto.

The fish extraction system 3000 may comprise means for varying the volume of air in the air pocket structure 3034 and changing the size of the air pocket 3032. The means may be a vent or valve that may be integrated into a compartment (e.g. into the extraction compartment 3031) that is able to remove air, or force air into the air pocket structure 3034, thereby increasing the air pressure of the air pocket 3032, and permitting an expansion of the volume of the air pocket 3032. Otherwise described, these means may selectively adjust the ratio of air and water in the air pocket structure 3034 as the air pocket structure 3034 will be filled with a volume of water for every volume of air that is removed therefrom and pumping air into the air pocket structure 3034 will remove water from the air pocket structure 3034 accordingly.

Rephrased, the air pocket structure 3034 comprises the air pocket 3032, whose size is adjustable by the means for varying the volume of air, and the rest of the volume of the air pocket structure 3034 is filled with water.

In some examples, the fish may be lured into the air pocket structure 3034, which in this example comprises an air pocket 3032, which is held within the fish enclosure 3105. The air may be removed from the air pocket 3032, which may encourage the fish to swim to the nearest air source or accumulation of air, which is accessible from the extraction compartment 3031, and which therefore requires the fish to swim through the separation compartment 3001 and into the extraction compartment 3031, where the fish may be extracted by a user. This may be advantageous for example in cases where the air source 3011 of the extraction compartment 3031 is located above water level 3111 and far from the fish enclosure 3105, then the fish in the fish enclosure 3105 may be more receptive towards the air pocket 3032. Luring the fish first to the air pocket 3032 in the air pocket structure 3034 whilst removing the air pocket 3032 from the air pocket structure 3034 afterwards may then encourage the fish to move towards the nowcloser air source 3011 of the extraction compartment 3031, thereby facilitating movement of fish from the fish enclosure 3105 into the extraction compartment 3031.

Alternatively or additionally, some air may be left in the air pocket 3032 in the air pocket structure 3034, in order to deliberately select few fish for extraction. This may be beneficial in cases where a relatively small number of randomly selected fish are to be extracted and/or examined.

In this example, the separation compartment 3001 and the extraction compartment 3031 are directly connected such that they form one single compartment. The separation compartment 3001 is selectively accessible from the fish enclosure 3105 and the restriction arrangement 3004 may be used to selectively control the access thereto. If fish has moved inside the separation compartment 3001 and extraction compartment 3031, the restriction arrangement 3004 may be closed to restrict the movement of the fish from the extraction compartment 3031 back to the fish enclosure 3105.

Figure 31 shows another example, wherein the separation compartment 3001 is directly connected to the extraction compartment 3031 such that they form one single compartment. In this example, there is an access port 3003 connecting the separation compartment 3001 to the fish enclosure 3105. Herein, the access port 3003 connects the main body of the fish enclosure 3105 with the air pocket structure 3034 to the separation compartment 3001. In this embodiment the fish may directly swim from the air pocket structure 3034 to the separation compartment 3001 which may assist to increase the number of fish entering the separation compartment 3001 and increase the efficiency of the fish extraction system 3000 overall. As in the previous example, the access port 3003 comprises a restriction arrangement 3004 to selectively permit access therethrough. As such access to the separation compartment 3001 is via the restriction arrangement.

Shown in Figure 32, the separation compartment 3001 may comprise a plurality of access ports 3003a,b from the fish enclosure 3105. As shown in the embodiment of Figure 32, one of the plurality of access ports 3003a may connect the fish enclosure 3105 directly to the separation compartment 3031 while another of the access ports 3003b may connect the separation compartment 3001 to the air pocket structure 3034. Such a configuration may permit an increased number of fish to enter the separation compartment 3001, and may permit fish to continue to enter the separation compartment 3001, for example, in situations where the water level in the air pocket structure 3034 is too low to permit access from the access port 3003 in the air pocket structure 3034. The plurality of access ports 3003a,b each comprise a restriction arrangement 3004 to selectively permit access to the separation compartment 3001. As can also be seen in Figure 32, an access port 3003a may also be arranged on a horizontal surface. Here, the access port 3003a is oriented in a substantially horizontal orientation. The access ports 3003a,b may be arranged on a horizontal surface in a horizontally orientation, on a vertical surface in a vertical orientation or in another orientation.

Figure 33 shows the example as illustrated in Figure 31 and illustrates how a fish may be lured into the fish extraction system 3000. Here, the fish starts its journey in the fish enclosure 3105 and may swim through the entry port 3033 into the air pocket structure 3034, e.g. because it feels the need to adjust its swim bladder and is lured by the air pocket 3032. From the air pocket structure 3034 the fish may swim through the access port 3003 into the separation compartment 3001 being lured by the access port 3010 to the air source 3011. When the fish is inside the separation compartment 3001 the restriction arrangement 3004 may be used to prevent the fish from swimming back into the fish enclosure 3105 enabling extraction of the fish from the separation compartment 3001 – for example, once a desired number of fish have entered the separation compartment 3001, the cover may be selectively configured from an open configuration to a closed configuration by a user, thereby preventing the fish from swimming through the access port 3003 and into the fish enclosure 3105. Once in the separation compartment 3001, the fish may be lured into the extraction compartment 3031 (not illustrated in Figure 33) due to a supply of air therein. Once in the extraction compartment 3031, the fish may be extracted by a user. Although illustrated as a single structure, the term “compartment”, i.e. “separation compartment” and “extraction compartment” may refer to the bottom and top of a structure.

Figure 34 shows another example bearing similarities to the previously described examples. In this example, there are illustrated two restriction arrangements 3004a, 3004b. One of the restriction arrangements 3004a is similar to that as previously described in that the restriction arrangement 3004a is configurable to restrict or permit access form the fish enclosure 3105 to the separation compartment 3001. A second of the restriction arrangements 3004b is located at the entry port 3033 to the air pocket structure 3031. Herein the restriction arrangement 3004b is a sliding cover movable in horizontal direction, which may be used to provide selective access to the air pocket structure 3031. In another example the restriction arrangement 3004b may be a hatch, a valve, a revolving door or any other means enabling to temporarily block the connection 3033 from the air pocket structure 3034 to the fish enclosure 3105. The restriction arrangement 3004b may be non-permeable to both water and fish or may be only non-permeable to the fish allowing water to pass, e.g. comprising holes, slits or a net. In some examples, the restriction arrangements 3004a,b may be a solid hatch or may be a hatch having holes therein to enable water permeability. In some examples the restriction arrangements 3004a,b may be or comprise a net structure with a drawstring arrangement. The net structure may comprise an opening therein that is surrounded by a drawstring, and which may be closed/tightened or opened/loosened by operation of the drawstring. Pulling the drawstring moves the net surrounding the opening closer together and prevents fish from swimming through the opening. To re-open the conduit, the net structure may comprise an actuator or the net structure may tend to open itself when there is no tension applied to the drawstring, e.g. because a water current applies a force onto the net structure. The cover may be actuated by a user, for example via a remote actuating mechanism.

In this example, the separation compartment 3001 comprises the air pocket structure 3034, and the restriction arrangement 3004b, enabling selective access to the separation compartment 3001 from the fish enclosure 3105, and enabling access to the extraction compartment 3034 via the access port 3003. It may be possible to remove the air pocket structure 3034 from the separation compartment. As explained previously, the fish may continue to swim towards the location of the air pocket structure 3034 out of habit, or because they feel safe in doing so. Finding that the air pocket has been removed, a fish may continue to seek air, which may result in the fish swimming to the nearby extraction compartment 3034.

In some examples, the restriction arrangement 3004b may provide little or no restriction to the movement of fish, and in some examples the access port 3003 may be permanently open.

Additionally, the fish extraction system 3000 may comprise shifting arrangements 3007,3037 to move the fish, shown by arrows and broken lines (i.e. broken dot-dash lines) in Figure 34. The separation compartment 3001 may comprise shifting arrangement 3007 to move the fish inside the separation compartment 3001, herein in a horizontal direction, and the extraction compartment 3031 may comprise shifting arrangement 3037 to move the fish inside the extraction compartment 3031, herein in a vertical direction. These shifting arrangements 3007,3037 may be used to move the fish in the respective compartment 3001,3031 enabling to not only rely on the fish being lured to the air source 3011 but rather enabling to move the fish from the air pocket 3032 in the air pocket structure 3034 in the separation compartment 3001 to the extraction port 3010 in the extraction compartment 3034. The shifting arrangements for moving the fish 3007,3037 may comprise separate systems or may be combined in a single system. The shifting arrangements for moving the fish 3007,3037 may move the fish into the fish traps 3020a,b.

The shifting arrangements for moving the fish 3007,3037 may move the fish by creating water currents, air flows or using water pressure or air pressure as well-known live fish transportation systems use. Alternatively or additionally, the shifting arrangements 3007,3037 for moving the fish may reduce the space in the compartments accessible to the fish, e.g. by moving a piston, a moveable wall, a panel or a net, thereby forcing the fish to swim to the remaining space. The shifting arrangements 3007,3037 for moving the fish may be permeable to water, thereby reducing the energy needed to move the shifting arrangements 3007,3037 and preventing from creating pressures in the compartments 3001,3031.

The shifting arrangements 3007, 3037 may be in the form of moveable bulkheads. The moveable bulkheads may be in the form of a frame having a net spanning the openings therein, or a solid panel comprising plastic and/or metal which may be permeable to water. The moveable bulkhead 3037 may be oriented vertically and moveable horizontally within the air pocket structure 3034 in order to crowd fish in the air pocket structure 3034 towards the access port 3003, and thereby closer to the extraction compartment 3031. Similarly, there may be a moveable bulkhead in the separation compartment 3001, which may be horizontally oriented and vertically moveable to physically move fish towards the extraction compartment 3031.

In one example, the restriction arrangement 3004b is opened, luring fish to the air pocket 3032 in the air pocket structure 3034 of the separation compartment 3001. After collecting a sufficient number of fish in the separation compartment 3001, the restriction arrangement 3004b may be closed and the restriction arrangement 3004a may be opened, enabling the fish collected in the separation compartment 3001 to swim into the extraction compartment 3031 but preventing the fish from returning into the fish enclosure 3105. The shifting arrangement 3037 may be used to move the fish into the extraction compartment 3031, e.g. by forcing the fish to swim in this direction due to a net, wall etc. pushing them towards the access port 3003. When the fish have been moved to the extraction compartment 3031, the restriction arrangement 3004a may be closed, thereby trapping the fish in the extraction compartment 3031. The shifting arrangement 3007 may be used to move the fish in the extraction compartment 3031 towards the extraction port 3010, e.g. upwards as the fish may be collected at a higher elevation. As the fish moves towards the extraction port 3010, it may pass through fish traps 3020a,b, which may have the effect of preventing movement of the fish back to the bottom of the extraction compartment 3031. The shifting arrangement 3037 may be moved back to its starting position indicated in Figure 34, e.g. retracted, and the restriction arrangement 3004b may be opened to enable another cycle of fish extraction from the fish enclosure 3105.

Alternatively or additionally, the extraction compartment 3034 may comprise means to selectively adjust the water level in the extraction compartment 3034. E.g. the extraction compartment 3034 may be hermetically sealed and a pressure may be created in the extraction compartment 3034 to adjust the water level in the extraction compartment 3034. The extraction compartment 3034 may comprise a pump or the like to adjust the water level in the extraction compartment 3034. Thereby the fish in the extraction compartment 3034 may be aggregated at the respective water level or the water level may be reduced to shift the water level close to the access port 3003 increasing the luring potential of the air source 3011 for the fish in the fish enclosure 3105.

Additionally or alternatively, the separation compartment 3001 may comprise an own air source to lure fish from the fish enclosure 3105 or an air pocket structure 3034 to the separation compartment 3001 and therefrom to the extraction compartment.

CLAUSE C1. A fish extraction system 3000 for extracting fish from a fish enclosure 3105, the fish extraction system 3000 comprising:

a separation compartment 3001 for separating at least one fish from a farmed fish group, the farmed fish group being in a fish enclosure 3105, the separation compartment 3001 being selectively accessible from the fish enclosure 3105;

an extraction compartment 3031 for extracting a fish therefrom, the extraction compartment 3031 being accessible from the separation compartment 3001 and comprising an extraction port 3010 accessible by a user to extract a fish therefrom;

a restriction arrangement for restricting movement of a fish from the fish extraction compartment 3031 and to the fish enclosure 3105.

CLAUSE C2. The fish extraction system 3000 of clause C1, wherein the extraction compartment 3031 comprises a lure therein for attracting a fish thereto.

CLAUSE C3. The fish extraction system 3000 of clause C2, wherein the lure is an air source 3011.

CLAUSE C4. The fish extraction system 3000 of any preceding clause, wherein the separation compartment 3001 is directly connected to the extraction compartment 3031 such that they form one single compartment.

CLAUSE C5. The fish extraction system 3000 of any preceding clause, wherein the separation compartment 3001 is integrated into the fish farm 3100.

CLAUSE C6. The fish extraction system 3000 of any preceding clause, wherein the separation compartment 3001 comprises an air pocket structure 3034 having an air pocket located therein and functions to selectively provide access to the air pocket 3032.

CLAUSE C7. The fish extraction system 3000 of clause C6, wherein access to the extraction compartment 3031 from the separation compartment 3001 is selectively controllable by a user, and access to the air pocket 3032 in the separation compartment 3001 is restricted when access to the extraction compartment 3031 is permitted.

CLAUSE C8. The fish extraction system of clause C6 or C7, wherein the air pocket structure 3034 comprises means for varying the volume of the air pocket 3032.

CLAUSE C9. The fish extraction system 3000 of any preceding clause, wherein the restriction arrangement 3004 comprises a selectively openable cover positioned in at least one of the extraction compartment 3031 and the separation compartment 3001.

CLAUSE C10. The fish extraction system 3000 of any preceding clause, wherein the restriction arrangement 3004 permits unidirectional movement therethrough.

CLAUSE C11. The fish extraction system 3000 of clause C10, wherein the restriction arrangement 3004 comprises a hinged cover.

CLAUSE C12. The fish extraction system 3000 of any preceding clause, wherein the extraction compartment 3031 comprises a waterline.

CLAUSE C13. The fish extraction system 3000 of any preceding clause, wherein at least part of the extraction compartment 3031 is located above the water level 3111 of the body of water in which the fish farm 3100 is located.

CLAUSE C14. The fish extraction system 3000 of any preceding clause, wherein the separation compartment 3001 comprises a shifting arrangement 3037 for moving a fish from the separation compartment 3001 to the extraction compartment 3034.

CLAUSE C15. The fish extraction system 3000 of clause C14, wherein the shifting arrangement 3037 comprises a moveable wall or panel for physically moving a fish from the separation compartment 3001 to the extraction compartment 3031 by gradual reduction of the space available in the separation compartment 3001 to the fish.

Claims

1. A fish farm (200) comprising:

a first enclosure (230),

a second enclosure (240);

the first enclosure (230) being connected to the second enclosure (240) by an access arrangement (250) for selectively permitting movement of a fish between the first enclosure (230) and the second enclosure (240); and

the first enclosure (230) and the access arrangement (250) being positioned within the fish farm (200) such that both the first enclosure (230) and the access arrangement (250) are fully submergible when positioned in a body of water.

2. The fish farm (200) according to claim 1, comprising a restrictor arrangement (260) in cooperation with the access arrangement (250) for selectively permitting access between the first and second enclosures (230,240).

3. The fish farm (200) according to claim 2, wherein the restrictor arrangement (260) is located in the access arrangement (250).

4. The fish farm (200) according to claim 2 or 3, wherein the restrictor arrangement (260) comprises a plurality of rigid bars with spaces therebetween for permitting a fish to pass therethrough.

5. The fish farm (200) according to any of claims 2 to 4, wherein the restrictor arrangement (260) comprises a first and a second set of rigid bars (264,265), each set having spaces therebetween for permitting a fish to pass therethrough, the first set of rigid bars (264) being slidably moveable relative to the second set of rigid bars (265) between an open position, in which the spaces between the rigid bars of the first and second set of rigid bars (264,265) are aligned, and a closed position, in which the rigid bars of the first set of rigid bars (264) are aligned with the spaces of the second set of rigid bars (265), thereby restricting passage of a fish therethrough.

6. The fish farm (200) of claim 5, wherein the first set of rigid bars (264) may be positioned relative to the second set of rigid bars (265) such that the bars of the first set of rigid bars (264) partially overlap with the spaces of the second set of rigid bars (265), thereby reducing the space available for passage of a fish therethrough.

7. The fish farm (200) according to any preceding claim, comprising a sensor arrangement (269) comprising a counter for counting the number of fish passing through the access arrangement (250).

8. The fish farm according to any preceding claim, comprising a lure arrangement (245) for motivating movement of a fish from the first enclosure (230) to the second enclosure (240).

9. The fish farm (200) according to claim 8, wherein the lure arrangement comprises at least one of: a supply of fish feed, an air pocket, a light, speaker/sound transmitter and a fluid propeller.

10. The fish farm (200) according to claim 8 or 9, wherein the lure arrangement is located in each enclosure (230,232,240) of the fish farm (200).

11. The fish farm (200) according to any of claims 9 to 11, wherein the lure arrangement is able to be selectively activated within an enclosure (230,232,240) of the fish farm (200).

12. The fish farm (200) according to any preceding claim, wherein at least one of the first and second enclosures (230,240) comprises a volume restriction device (280) for reducing the volume of space available to a fish therein.

13. The fish farm (200) according to any preceding claim, wherein both the first and second enclosures (230, 240) are contained within an outer enclosure (211).

14. A method for managing fish in a fish farm (200), comprising:

providing a first enclosure (230) and a second enclosure (240) the first enclosure (230) being connected to the second enclosure (240) by an access arrangement (250) for selectively permitting movement of a fish between the first enclosure (230) and the second enclosure (240);

housing a fish in the first enclosure (230);

permitting a fish in the first enclosure (230) access to the second enclosure (240) by positioning the first enclosure (230) and the access arrangement (250) such that both are fully submerged when positioned in a body of water.

15. The method of claim 14, comprising using the lure arrangement to motivate a fish to move from the first enclosure (240) to the second enclosure (232).