Processing marine organisms

Abstract

A method of processing marine or water-borne organisms (32), for example by killing (via killing mechanism 24 and / or 22) and / or imaging (via a camera 48) the organisms, comprises entraining the organisms in a flow (30) of water and trapping the organisms on a filter (10) interposed in the flow. The filter, supporting the trapped organisms, is moved relative to a direction of the flow through the filter. After processing the organisms supported by the filter, the processed organisms are purged from the filter.

Description

[0001] Processing marine organisms

[0002] This invention relates to systems and methods for processing marine or water-borne organisms. The invention relates particularly to systems and methods for killing and / or imaging ectoparasites, for example parasite larvae, in farmed fish enclosures.

[0003] Farming allows fish to be raised in seawater or freshwater environments until they reach a required market size. Examples of farmed fish include marine species such as salmon, sea trout, sea bream, sea bass, halibut, and turbot as well as freshwater species such as freshwater trout, carp, and tilapia.

[0004] Farmed fish are typically confined in cages in the water or in net pens. Although a net pen confines the fish being farmed, it does not prevent parasites such as sea lice from drifting into the pen and possibly infesting the fish. Parasite infestations can cause significant damage to farmed fish as the parasites feed on the skin, blood, and mucus of the fish to survive. When attached, the parasites cause open wounds and weaken the fish, resulting in unmarketable or less valued products.

[0005] Traditional methods for controlling sea lice infestation typically involve the use of chemical treatments. These methods include using active chemicals in a bath treatment or added into the fish feed. While these treatments may be effective to some extent, they can contaminate the environment and parasites can develop resistance to chemical or biochemical agents over time.

[0006] Mechanical and biological control methods have been explored as alternatives to chemical treatments. Mechanical methods such as waterjets remove the parasites from fish but can cause damage to the fish in doing so, such as scale removal. Biological methods include introducing natural predators to sea lice into the aquaculture environment. However, introducing predators can disrupt the local marine ecosystem, affecting other species and posing biosecurity risks.

[0007] Consequently, it is evident that parasites should ideally be removed from fish pens before they attach to the fish. There have been many such proposals in the prior art. For example, WO 2021 / 038179 discloses a filter apparatus for filtering parasites from water. Pressurised air is injected through an air injection port in a conduit, creating a pressure differential in the conduit between a water inlet and outlet, causing water to be drawn into the water inlet, through the conduit and into the filter. Although this apparatus is beneficial in some respects, the filter can become blocked when full of parasites and thus, must be removed from the apparatus for frequent cleaning.

[0008] NO 345976 discloses a pelagic crustacean parasite collection device. The device is transparent and is provided with a flashing light source to attract pelagic crustacean parasites. Parasites that approach the device follow water flow through an inlet in the device and are carried with the water flow towards a pump. The parasites are then filtered from the water flow by a filter on the pump.

[0009] As with WO 2021 / 038179, NO 345976 requires the filter to be cleaned and replaced once blocked, which can be slow and inefficient. In addition, as the collection device must be attached to a frame 58 mooring of the pen, the device does not have the ability to traverse the pen to collect further parasites. This limits the catching area and ultimately, the number of parasites that can be caught.

[0010] In an even more cumbersome solution, NO 337292 discloses a device for collecting and destroying lice present in water. The device comprises a submerged container that is connected to a pump designed to suck water and lice into the container through slits or openings in the container. Once the parasites have been sucked into the container, they pass through a mill where they are ground. The grinder may also employ UV radiation.

[0011] Although NO 337292 can be considered an effective termination device, the remnants of the lice must be collected in a separate collection unit using a fine strainer. This is a laborious process as the water and lice must be drained from the collection tank, discharging the water to the sea while lice residues are removed and transported away.

[0012] NO 20140640 discloses a system for harming parasites present in water. Parasites are attracted to light emitted from devices attached to the system. Once the parasites are lured toward a conductive surface of the device, the device emits a series of electrical pulses that kill or weaken the parasites. However, using electrical pulses may inadvertently affect other aquatic life in the aquaculture environment that may be sensitive to changes in electrical conductivity. In addition, marine infrastructure that requires electrical currents can be complex and costly. Against this background, the invention resides in a method of processing marine or water-borne organisms. The method comprises: entraining the organisms in a flow of water; trapping the organisms on a filter interposed in the flow; moving the filter, supporting the trapped organisms, relative to a direction of the flow through the filter; processing the organisms supported by the filter; and purging the processed organisms from the filter

[0013] The method may further comprise moving the trapped organisms out of the flow before processing them. For example, the filter can be moved in a direction transverse to the direction of the flow. The filter can be moved continuously or intermittently, in a stepwise manner.

[0014] The trapped organisms may be conveyed, while supported by the filter, to at least one processing zone at which the trapped organisms are processed. The processed organisms may then be moved, while supported by the filter, before being purged from the filter. For example, the filter can be moved to a purge zone at which the processed organisms are purged. The filter may be moved to the purge zone from a trap zone at which the organisms are trapped. The filter may be moved from the trap zone to the purge zone via the at least one processing zone.

[0015] An outgoing flow of water can be conveyed through the filter to purge the processed organisms. Elegantly, the outgoing flow may comprise water of an incoming flow that carried the entrained organisms to the filter. The incoming flow and the outgoing flow can move in a common flow direction. A first side of the filter can be presented to the incoming flow and an opposed second side of the filter can be presented to the outgoing flow.

[0016] The method of the invention may also comprise rotating the filter after trapping the organisms and before purging the processed organisms. The filter can be rotated about an axis transverse to the flow. For example, the method may include passing the flow through a drum that defines the filter, the flow moving in a direction transverse to a central longitudinal axis of the drum. The method may also include driving the flow from within the drum and / or from outside the drum.

[0017] Processing the organisms may comprise exterminating the organisms supported by the filter, for example by exposing the trapped organisms to at least one killing mechanism. Preferably, the trapped organisms are exposed to at least two killing mechanisms that may employ ultraviolet and / or ultrasonic energy respectively in either order or simultaneously. The method may involve moving the filter to a kill zone at which the processed organisms are exterminated, the kill zone being in the at least one processing zone.

[0018] Processing the organisms may instead, or additionally, comprise capturing images of the organisms supported by the filter. For example, the filter may be moved to an imaging zone at which the processed organisms are imaged, the imaging zone being in the at least one processing zone. Images may be captured when the organisms supported by the filter are out of the water. Movement of the filter can be paused while capturing the images or images can be captured during movement of the filter.

[0019] Where imaging is employed, the method of the invention may also include assessing the captured images of the organisms and controlling extermination of the organisms in response to that assessment.

[0020] The flow can be driven from upstream of the filter or downstream of the filter, by movement of an external body of water relative to the filter, by moving the filter through a body of water, for example by thrust of the driven flow, and / or by moving the filter along a path through an external body of water.

[0021] In an example of the invention, the filter can be moved through a body of water along a looped path and movement along that path can be driven by applying force from an incident flow of water. In that case, the filter can be moved alternately in upstream and downstream directions relative to the incident flow.

[0022] Movement of the filter in the downstream direction can be driven by orienting a flap in an active orientation transverse to the incident flow, the flap being movable along the path with the filter and being pivotable relative to the filter. A concave face of the can may be presented in opposition to the incident flow when in the active orientation.

[0023] The flap can be flipped from the active orientation to an intermediate orientation in which the flap is transverse to the incident flow but reversed relative to the active orientation. For example, a convex face of the flap can be presented in opposition to the incident flow when in the intermediate orientation. Conveniently, the force of the incident flow can be used to flip the flap into the intermediate orientation.

[0024] The flap can be oriented in a passive orientation, generally aligned with the incident flow, during movement of the filter in the upstream direction, with free pivotal movement of the flap relative to the filter during movement of the filter in the upstream direction.

[0025] The inventive concept embraces a corresponding system for processing marine or waterborne organisms. The system comprises: an incoming flow path configured to direct an incoming flow of water to a filter interposed in the incoming flow path, the filter being arranged to trap organisms entrained in the incoming flow; at least one processing mechanism configured to process the organisms trapped by the filter; and an outgoing flow path configured to direct an outgoing flow from the filter to entrain the processed organisms, thereby to purge the processed organisms from the filter.

[0026] The system may be configured such that the outgoing flow path receives water conveyed to the filter via the incoming flow path. The incoming flow path and the outgoing flow path may be mutually aligned with a common flow direction.

[0027] The at least one processing mechanism may comprise at least one killing mechanism, which may comprise an ultraviolet emitter, an ultrasonic transducer, an infrared emitter, a laser, a roller, a scraper, fresh water, desalinated water, and / or an auger press.

[0028] The at least one processing mechanism may instead, or additionally, comprise at least one imaging system positioned to capture images of the organisms trapped by the filter. The or each imaging system may be positioned to capture images when the organisms trapped by the filter are out of the water. Where at least one killing mechanism is employed, that mechanism can be controlled in response to signals from the at least one imaging system.

[0029] The system may also include a housing that houses the filter and that comprises an inlet channel defining the incoming flow path and an outlet channel defining the outgoing flow path. The housing may comprise inlet vanes that extend outwardly from opposing sides of an inlet opening of the inlet channel. Conveniently, the housing may be supported by a float and / or movable relative to a body of water to be driven through the body of water by thrust of the outgoing flow. The housing may be movable through the body of water by a supporting frame that Is movable relative to the body of water.

[0030] The filter may be movable relative to the housing from a trap zone opposed to the inlet channel to a purge zone opposed to the outlet channel. The filter may be movable to the purge zone from the trap zone via at least one processing zone at which the at least one processing mechanism is located. For example, the filter may be movable in a direction transverse to the incoming flow or may be pivotable about an axis extending transversely to the incoming flow. Conveniently, the filter may be a drum through which the incoming flow passes to become the outgoing flow. The drum may be movable from the trap zone to the purge zone via a processing zone at which one or more killing or imaging mechanisms are located.

[0031] The system may also comprise an impeller disposed in the drum and / or in the incoming flow path and / or in the outgoing flow path to drive the incoming and outgoing flows.

[0032] The housing may further comprise a flap that is movably mounted to and extends outwardly from the housing. The flap may be on a side of the housing opposed to the inlet channel. The flap may be pivotably mounted to the housing, offset to one side of the outlet opening. The flap may have an outboard portion that is inclined relative to an inboard portion of the flap. Conveniently, movement of the flap relative to the housing may be limited by stops that extend outwardly from opposing sides of an outlet opening of the outlet channel.

[0033] The system may be positioned in a body of water and mounted on, and movable through the water with, a supporting frame. The frame may, for example, join to a support, such as a float, via a hub about which the frame can rotate relative to the support around an upright axis.

[0034] The frame may be rotatable relative to the support by a flow of water that is incident on the system and / or by thrust of water flowing through the system. The support may be arranged to drive rotation of the frame and the system.

[0035] Advantageously, the flap may be movable to extend from the housing in a trailing direction with respect to a direction of movement of the system through the water. The inlet channel may be in a forward position and the outlet channel may be in a rearward position with respect to a direction of movement of the system through the water.

[0036] Conveniently, two or more systems may be positioned in a body of water at similar or respectively different depths to increase the volume of treated water. The systems may be mounted on, and movable through the water with, a common supporting frame. The systems may also be mounted on respective arms that extend laterally from a central member of the frame.

[0037] In order that the invention may be more readily understood, reference will now be made, by way of example, to accompanying drawings in which:

[0038] Figure 1 is a perspective view of a drum filter in a first embodiment of the invention;

[0039] Figure 2 is a side view of the drum filter of Figure 1 ;

[0040] Figure 3 is a schematic side view of an extermination system comprising a housing around the drum filter of Figures 1 and 2;

[0041] Figure 4 is a schematic side view of an extermination system corresponding to Figure 3 but including an imaging system and not necessarily including the housing;

[0042] Figures 5a to 5d are a sequence of schematic side views that illustrate stepwise movement of the drum filter of the extermination system of Figure 3;

[0043] Figure 6 is a schematic side view of a variant of the extermination system in which flow through the drum filter is driven by a downstream impeller;

[0044] Figure 7 is a schematic side view of a further variant of the extermination system in which flow through the drum filter is driven by an upstream impeller;

[0045] Figure 8 is a schematic side view of a further variant of the extermination system in which imaging is performed out of water; Figure 9 is a schematic side view of a further variant of the extermination system in which water is pumped onto the drum filter;

[0046] Figure 10 is a schematic plan view of extermination systems of Figure 3 suspended in water by a rotating frame supported by a float or other supporting member;

[0047] Figure 11 is a schematic side view corresponding to Figure 10;

[0048] Figure 12 is a schematic side view of an extermination system of Figure 3 suspended from a float or other supporting member;

[0049] Figure 13 is a schematic plan view of a further embodiment of an extermination system;

[0050] Figure 14 is a schematic side view corresponding to Figure 13;

[0051] Figure 15 is a schematic side view of a processing system corresponding to Figure 3 but including an imaging system and not necessarily including a housing or an extermination system;

[0052] Figure 16 is a schematic side view of processing systems suspended in water by a rotating frame driven by a motorised float or other supporting member;

[0053] Figures 17 and 18 are perspective views of processing systems suspended by variations of rotating frames; and

[0054] Figures 19a to 19k are a sequence of schematic plan views of processing systems suspended by a frame rotating under the influence of an incident water flow.

[0055] Referring firstly to Figures 1 and 2 of the drawings, Figure 1 shows a filter of an extermination system according to an embodiment of this invention and Figure 2 shows a side view of the filter of Figure 1. In this example, the filter is a cylindrical or tubular structure, or drum 10, through which incoming water flow passes. The drum 10 extends along a central longitudinal axis A, around which the drum 10 is rotationally symmetrical.

[0056] A foraminous tubular wall 12 of the drum 10, which may be penetrated by holes, slits, or other openings, includes a longitudinal series of raised circumferential projections designed to trap organisms entrained in water flowing across and through the wall 12. Typically, the projections lie parallel to one another and are mutually spaced between 100pm to 250pm. The closely spaced projections enable the capture of ectoparasites in their larval stage as well as pre-adults and adult stages of the ectoparasites that detach from host fish and are present in the water column. However, the closely spaced projections inhibit the capture of other small organisms. The projections may be arranged in parallel circumferential loops in planes orthogonal to axis A or helically, wrapping around the drum 10 from one end of the drum 10 to the other end of the drum 10. Other arrangements and spacings are also possible. Different screening input filters (not shown) may also be used to screen particles such as feed particles, organisms, larger organisms that are above a target size.

[0057] The drum 10 has internal bars 14 that lie parallel to one another and to axis A. The bars 14 are equiangularly spaced around axis A and extend between end flanges 16 that lie in planes orthogonal to axis A. The bars 14 support the tubular wall 12 of the drum 10 while allowing water to flow through the spaces between the bars 14.

[0058] Figures 3 and 4 show schematics of an extermination system 18 including the drum 10. In Figure 3, the drum 10 is encased in a housing 20 and is driven for continuous or stepwise rotation about axis A relative to the housing 20. The housing 20 includes an inlet channel 26 and an outlet channel 42. The inlet channel 26 receives and guides an incoming water flow 30 to the drum 10 and the outlet channel 42 expels and guides an outgoing water flow 46 from the drum 10.

[0059] In this example, the drum 10 also contains an impeller 34 that drives the flow of water along the inlet and outlet channels 26, 42 and through the drum 10. The impeller 34 is mounted on a web 36 that is fixed relative to the housing 20, here intersecting axis A of the drum 10. The drum 10 is therefore rotatable around the impeller 34 and the web 36.

[0060] When the impeller 34 is driven, it generates a drop in pressure on an inlet side, shown to the right in Figures 3 and 4, and an increase in pressure on an outlet side, shown to the left in Figures 3 and 4. This drives the incoming flow 30 along an incoming flow path 38. The incoming flow path 38 directs the incoming flow 30 into the inlet channel 26 toward a trap zone on the outside of a first, upstream side 28 of the tubular wall 12 of the drum 10, opposed to the incoming flow 30. Thus, marine organisms 32 such as ectoparasites entrained in the incoming flow 30 (shown here as black squares, when alive) are sucked onto, trapped by and held against the external projections on the tubular wall 12 of the drum 10.

[0061] The flow of water continues through and out of the drum 10 on an outgoing flow path 38 that directs the outgoing flow 46 through and away from a second, downstream side 40 of the drum 10 at a purge zone diametrically opposed to the trap zone on the first side 28 of the drum 10. As the outgoing flow 46 travels in the same direction as the incoming flow 30, the outgoing flow 46 impinges on the inside of the tubular wall 12 on the second side 40 of the drum 10 and then flows through the tubular wall 12. The force of that inside-out water flow through the tubular wall 12 propels dead organisms 44 (shown here as white circles) away from the tubular wall 12 after they have been exterminated. This propulsion purges the dead organisms 44 from the drum 10 and out of the outlet channel 42, entrained in the outgoing flow 46.

[0062] While the incoming flow 30 of water pins the live organisms 32 against the tubular wall 12 of the drum 10, the drum 10 rotates anticlockwise as shown to carry the organisms 32 from the trap zone to a processing zone, exemplified here by a kill zone where the organisms 32 are exposed to one or more killing mechanisms. Here, the organisms 32 are processed by being exposed to the or each killing mechanism for a sufficient dwell time to kill most or substantially all of the organisms 32 that are supported on the drum 10 in the kill zone. In this example, the kill zone is located out of the incoming water flow 30, and may indeed be in an air-filled upper chamber within the housing 20 as will be explained, but can instead be submerged as shown here.

[0063] In this example, the system 18 includes two different killing mechanisms angularly spaced around the outside of the drum 10 on an upstream portion of the drum 10 to kill the organisms 32 trapped on the drum 10. The extermination mechanisms may include an ultrasonic (US) transducer 22 that kills the organisms 32 by exposing them to high- frequency sound waves and an ultraviolet emitter 24 that kills the organisms 32 by exposing them to ultraviolet (UV) radiation. Alternatively, or additionally, lasers or mechanical extermination mechanisms such as rollers, scrapers, and / or auger presses or fresh or desalinated water may be used to kill the organisms 32.

[0064] In the example shown in Figure 4, the system 18 further includes a camera 48 positioned in the processing zone to obtain images of the organisms 32 trapped on the drum 10. Here, the camera 48 is shown positioned in an imaging zone between the trap zone and the kill zone to process the live organisms 32 by imaging them. A camera in the processing zone could instead, or additionally, be positioned in an imaging zone between the kill zone and the purge zone to image the dead organisms 44. Feedback from the images captured by the or each camera 48 can be used to control the killing mechanisms 22, 24 and / or the drum 10 to make extermination more effective, for example by adjusting the dwell time in the kill zone or by adjusting the intensity, the wavelengths or the mix of the killing mechanisms 22, 24.

[0065] The drum 10 supporting the dead organisms 44 continues to turn relative to the flow of water until the dead organisms 44 are purged from the drum 10 at the purge zone. Once at the purge zone, the dead organisms 44 are expelled from the tubular wall 12 of the drum 10 by conveying the outgoing flow 46 of water through the wall 12. The outgoing flow 46 comprises the incoming flow 30 that carried the entrained live organisms 32 to the drum 10.

[0066] The process of trapping, exterminating (after and / or before optionally imaging) and purging organisms repeats as the drum 10 turns and successive portions of the tubular wall 12 of the drum 10 move through each respective zone. In this respect, Figures 5a to 5d exemplify how the drum 10 can turn in a stepwise manner, it being understood that continuous rotation of the drum 10 is also possible.

[0067] In Figure 5a, live organisms 32 are shown entrained in the incoming flow 30 of water. The incoming flow 30 is directed towards a first side 28 of the drum 10 as the flow of water travels through the wall 12 of the drum 10 in a direction transverse to the central longitudinal axis A of the drum 10. The organisms 32 are thereby trapped by the wall 12 of the drum 10 as shown in Figure 5b. After a period of time sufficient to trap a desired volume of organisms 32 in the trap zone, the drum 10 turns through an angle sufficient to move the trapped organisms 32 from the trap zone to the kill zone as shown in Figure 5c. In the kill zone, UV and / or US are employed to kill the trapped organisms 32. After a dwell time sufficient to kill the organisms 32 in the kill zone, the drum 10, supporting the now dead organisms 44, turns through an angle sufficient to move the dead organisms 44 from the kill zone to the purge zone, as shown in Figure 5d.

[0068] The drum 10 turns relative to the flow of the water while the flow of water continues through the drum 10, such that the outgoing flow 46 impinges on the inner side of the wall 12 of the drum 10 at the purge zone. The force of the water flowing out through the wall 12 from within the drum 10 purges the trapped dead organisms 44 from the drum 10.

[0069] Figures 6 to 9 show variants of the extermination system 18.

[0070] In Figures 6 and 7, the impeller 34 is disposed outside the drum 10. Specifically, Figure 6 shows the impeller 34 disposed in an outlet channel 42 downstream of the drum 10 whereas Figure 7 shows the impeller 34 disposed in an inlet channel 26 upstream of the drum 10.

[0071] In Figure 8, the housing 20 traps an air pocket 52 that accommodates an upper portion of the drum 10. The level of the air / water interface 54 may be controlled using sensors and pumps to compress air in the air pocket 52. As the drum 10 turns relative to the housing 20 and the flow of water, the live organisms 32 trapped in the trap zone are exposed to US in the kill zone at 22 for a desired dwell time. Exposure to US may take place underwater as shown. The organisms 32 exposed initially to US are shown here as white squares.

[0072] The drum 10 continues to turn, exiting the water flow and entering the air pocket 52. The camera 48 captures images of the organisms 32 and the organisms 32 are then subject to UV at 24 for a desired dwell time.

[0073] Turning the drum 10 through the air pocket 52 speeds extermination as the organisms 32 are taken out of the water, improving optical kill methods. The air pocket 52 is also beneficial for clearer imaging using the camera 48, may be beneficial for UV transmission, and may also be beneficial for keeping the drum 10 clean. The drum 10, supporting the now dead organisms 44, continues to turn, exiting the air pocket 52 and re-entering into the water flow. The water that continues to flow through the drum 10 purges the dead organisms 44 from the drum 10.

[0074] In certain embodiments, the system may comprise a motor 55 or gearbox acting on the drum 10 to drive rotation of the drum 10 relative to the housing 20. The motor 55 or gearbox may be configured to provide continuous or stepwise drive to the drum, enabling the organisms 32 to be moved sequentially from the trap zone, through the kill zone and / or an imaging zone, to the purge zone. The motor 55 could be driven in various ways, for example electrically, hydraulically or by a turbine driven by water flow incident on the system or generated by motion of the system through a body of water.

[0075] In the example of Figure 9, the drum 10 is shown floating partially out of water. In this embodiment, water is driven from a target zone at a depth at which the parasite larvae are present and is pumped over the drum 10. As the pumped water impinges on the drum 19, organisms 32 entrained in the flow are trapped by the wall 12 of the drum 10. As the water flows over and through the drum 10 on a path offset laterally from the axis A, the momentum of the flow drives rotation of the drum 10 in the corresponding angular direction, moving trapped organisms 32 from the trap zone to the kill zone. In this example, the kill zone again is located out of the water, aiding extermination and imaging as explained above.

[0076] It will be apparent that the flow of water into, through and out of a filter such as the drum 10 will generate thrust when an extermination system 18 of the invention is in a body of water, especially where that flow is substantially unidirectional. The thrust will act in the direction of the flow and the reaction to that thrust will tend to propel the extermination system in a direction opposed to the flow.

[0077] If desired, the thrust acting on the extermination system 18 can be resisted by supporting the system 18 on a fixed mounting, for example fixed to the structure of a fish pen that surrounds and defines the body of water. Conversely, Figures 10 to 12 show embodiments that exploit the thrust to propel one or more extermination systems 18 through a body of water, hence increasing the volume of water in which organisms 32 can be trapped and killed. Figures 10 and 11 show an arrangement 56 in which two extermination systems 18 of the invention suspended via their housings 20 from a frame 58 that hangs from a float 62 or other support in a body of water 60. The float 62 is typically tethered in a fixed position with multiple mooring lines extending to an edge of the pen to prevent it from drifting in the water.

[0078] The frame 58 has an inverted T shape, comprising two arms 64 extending generally horizontally in mutually opposed directions from a generally vertical central member 66. The arms 64 terminate at their free ends in upright outer members 68 that suspend the extermination systems 18 from the arms 64.

[0079] At its upper end, the central member 66 joins to the float 62 via a hub that allows the frame 58 to rotate relative to the float 62 about an upright axis along which the central member 66 extends. The hub can accommodate a swivel connection that allows power and data signals to pass through from a topside control.

[0080] The arms 64 of the frame 58 support respective extermination systems 18 that are spaced horizontally from the central member 66. The extermination systems 18 are oriented so that their outlet channels 42 are directed transversely or orthogonally relative to the respective arms 64 in opposite directions in plan view and hence in a common circumferential direction about the upright axis of rotation. Consequently, the thrust acting on the extermination systems 18 drives rotation of the frame 58 about the upright axis relative to the float 62.

[0081] In operation, the extermination systems 18 therefore sweep around circular paths through the body of water 60 to increase the volume of water in which organisms 32 are trapped and killed. In this example, the extermination systems 18 are held at respectively different depths in the water because the outer members 68 have different lengths. Thus, the extermination systems 18 follow different circular paths stacked one above the other, further increasing the swept volume of water. In a variant, members of the frame 58 supporting the extermination systems 18 could be variable in length to change the depth and / or radius of the swept path, allowing one or more extermination systems 18 to track through an optimum target zone in a body of water 60.

[0082] Figure 12 shows an arrangement 56 in which an extermination system 18 of the invention is suspended via its housing 20 from a float 62 or other support in a body of water 60. Here, the extermination system 18 is suspended by a swinging, pivoting support 66 such as a rod or a flexible cable that hangs from the float 62. As the housing 20 takes in water containing live organisms through the inlet channel 26 and expels water containing dead organisms through the outlet channel 42, the system 18 is thrust through the water. The support 66 allows the system 18 to move through the water in a random or controlled pattern such as a figure of eight or a circle. Thus, extermination coverage increases as the system 18 not only moves back and forth, but also side to side. A frame 58 supporting two or more systems 18 of other embodiments could be similarly suspended from a float 62 or other support.

[0083] In the arrangements 56 of Figures 10 to 12, fixed-length mooring lines acting on the float 62 or other support could be replaced with variable-length lines extending to a set of smart winches. Such an arrangement could move the float 62 or other support linearly through X-, Y- and / or Z-axis cartesian coordinates, thereby allowing the or each extermination system 18 to traverse a greater proportion of the body of water 60.

[0084] Figures 13 and 14 exemplify an alternative filter arrangement. In this embodiment, the filter 10 is a flat, circular disc-like structure through which the incoming water flow passes to trap organisms entrained in the flow. The filter 10 turns about a central axis A that is orthogonal to the plane of the filter 10

[0085] Two impellers 34 drive the flow of water, namely, a first impeller 34 disposed on a first side of axis A that drives an incoming flow to the upstream face of the filter 10 and a second impeller 34 disposed on a second, opposite side of axis A that drives an outgoing flow away from the upstream face of the filter 10.

[0086] As the force of the water flow generated by the first impeller 34 traps organisms on the filter 10 at a trap zone, the filter 10 turns, either continuously or in a stepwise manner, from the trap zone to a kill zone at which killing mechanisms such as US 22 and UV emitters 24 facing the upstream side of the filter 10 act on the organisms trapped against the filter 10. The trap zone and the kill zone could be coincident, at the same or overlapping angular positions relative to axis A. This example also includes a camera 48 to image trapped organisms in the kill zone.

[0087] Once the organisms have been exterminated in the kill zone, the filter 10 turns to convey the dead organisms to a purge zone at which the flow driven by the second impeller 34 propels the dead organisms away from the filter 10. Now substantially clear of dead organisms, the filter 10 continues to turn into and through the trap zone and the process repeats.

[0088] In some embodiments, the system need not include a killing mechanism and may instead include an imaging system to obtain images of the organisms trapped on the drum before purging the imaged organisms, without necessarily killing them. In this respect, Figure 15 is a schematic view of the system in another aspect of the invention. Here, an image capturing system 19 includes a camera 48 positioned to obtain images of organisms 32 trapped on a drum 10.

[0089] In this example, the camera 48 is shown positioned in an imaging zone between the trap zone on the outside of the first, upstream side 28 of the tubular wall 12 of the drum 10, and the purge zone diametrically opposed to the trap zone on the first side 28 of the drum 10. The camera 48 is configured to image the live organisms 32 and provide feedback such as total number of organisms, population dynamics over time, and species identification. In this example, the trapped organisms are not exterminated and so the system 19 does not include any killing mechanisms. Thus, in the processing zone of this example, the kill zone is replaced by an imaging zone in which imaging takes place.

[0090] The drum 10 supporting the imaged organisms continues to turn relative to the flow of water until the imaged organisms are purged from the drum 10 at the purge zone. Once at the purge zone, the imaged organisms are expelled from the tubular wall 12 of the drum 10 by conveying the outgoing flow 46 of water through the wall 12. The outgoing flow 46 comprises the incoming flow 30 that carried the entrained organisms 32 to the drum 10.

[0091] The process of trapping, imaging and purging organisms repeats as the drum 10 turns and successive portions of the tubular wall 12 of the drum 10 move through each respective zone.

[0092] Figure 16 shows an alternative embodiment of the systems 18 of Figures 10 and 11. In this arrangement 56, the impellers 34 are absent from the two systems 18. Instead, the float 62 supporting the frame 58 includes a motor 70. In this example, the systems 18 need not generate thrust to drive rotation of the frame 58. Instead, the motor 70 disposed in the float 62 drives the central member 66 of the frame 58 to rotate about its upright axis, which in turn causes the frame 58, and the systems 18 supported by the frame 58, to turn relative to the float 62.

[0093] Optionally, as again shown here, the systems 18 are held at respectively different depths in the water because the outer members 68 of the frame 58 have different lengths, allowing the systems 18 to follow different circular paths stacked one above the other. Also, optionally, the arms 64 of the frame 58 could have different lengths. The systems 18 supported by the arms 64 and the outer members 68 of the frame 58 thereby sweep through the surrounding body of water 60 on circular paths of respective depths and radii, hence increasing the volume of water in which organisms 32 are trapped and processed by being imaged and / or killed.

[0094] Members of the frame 58 supporting the systems 18 could be variable in length to change the depth and / or radius of the swept path, allowing one or more of the systems 18 to track through an optimum target zone in a body of water 60.

[0095] Figures 17 and 18 illustrate further embodiments of the systems 18 mounted to and suspended from a rotatable support frame 58. In these examples, each system 18 may either be mounted atop or suspended beneath the respective upright outer member 68 extending from a respective arm 64 of the frame 58, allowing for flexible implementation depending on spatial requirements.

[0096] In the arrangement 56 shown in Figure 18, the frame 58 includes multiple arms 64 extending generally horizontally in mutually opposed directions from the generally vertical central member 66. The arms 64 are arranged in orthogonal pairs, forming a cruciform structure in plan view. These pairs of arms 64 can also be configured at different vertical levels along the central support member 66 to stagger the systems 18 vertically, thereby optimising coverage and flow interaction.

[0097] In open pens or other bodies of water where tidal flows are experienced, such flows could be used to assist or to replace the impeller-driven and / or motor-driven flows envisaged above. For example, tidal assistance could be employed to carry live organisms 32 toward the filter 10 and / or to carry exterminated organisms 44 from the filter 10 to decompose naturally in the water surrounding the pen or to be consumed by other microscopic species. Such dilution reduces the concentration of waste in the pen. The arrangements 56 of Figures 17 and 18 exemplify how rotation of the frame 58 can be driven by an incident flow 72 of water passing the frame 58 and the housings 20 of the systems 18. Such a flow 72 may be driven not only by tidal currents incident on the frame 58 and the housings 20 but also by moving the frame 58 and the housings 20 through a body of water, for example suspended beneath a moving surface vessel or other moving support. The incident flow 72 drives rotation of the systems 18 through the surrounding body of water, that rotary motion driving a local circumferential flow of water through each system 18 that entrains organisms on the filter 10 for processing and then purges organisms from the filter 10 after processing. Optionally, the systems 18 could have impellers to supplement the local flows of water and potentially to supplement thrust that helps to drive rotation of the systems 18, but this is not essential.

[0098] The housings 20 of the systems 18 are fixed relative to respective arms 64 that project laterally from an upright axis of rotation defined, in this example, by a central member 66. As noted in previous embodiments, the central member 66 can be supported by a float or other support. The inlet channels 26 of the systems 18 face forwardly, in the direction of rotation, whereas the outlet channels 42 of the systems 18 face rearwardly, opposed to the direction of rotation.

[0099] In this example, rotation is driven by a pivotable flaps 74 that are mounted on the housings 20 of the respective systems 18. The rotation mechanism is explained below with reference to Figures 19a to 19k. The flaps 74 extend rearwardly from the respective systems 18 in trailing relation. Each flap 74 can pivot relative to the housing 20 about an upright pivot axis which, in this example, is offset to one side of the respective outlet channel 42, that side being the radially inner side of the outlet channel 42 relative to the axis of rotation of the central member 66.

[0100] Here, the housing 20 of each system includes two forward inlet vanes 76 on the side of the housing 20 with the inlet channel 26 and two rearward stops 78 that protrude from the side of the housing 20 with the outlet channel 42. The inlet vanes 76 extend outwardly from opposing sides of an opening or mouth of the inlet channel 26 and splay apart to direct the incoming flow of water into the housing 20 via the inlet channel 26. The stops 78 similarly extend outwardly from opposing sides of an opening of the outlet channel 42. As will be explained, the stops 78 bear against the flap 74 at the limits of its range of pivotal movement, hence limiting pivotal movement of the flap 74 relative to the housing 20.

[0101] The flap 74 comprises an inner panel 80, whose inner end is pivotably connected to the housing 20, and a relatively short outer panel 82 that is inclined at an obtuse angle relative to the inner panel 80. The outer panel 82 is inclined forwardly relative to the inner panel 80, hence toward the direction of rotation of the systems 18. The inclination of the outer panel 82 relative to the inner panel 80 confers a convex shape to one side of the flap 74 and a concave shape to the other side of the flap 74.

[0102] Figures 19a to 19k show an arrangement 56 in plan view, in which first and second processing systems 18 respectively are fixed to the arms 64 and are rotatable with the arms 64 about an upright axis of rotation defined by a central member 66 of a frame 58. The systems 18 and the arms 64 rotate clockwise in this view, under the influence of an incident flow 72 such as a tidal current. Thus, in each cycle of rotation, each system 18 moves alternately with the flow 72 and then against the flow 72. Rotation of the systems 18 drives local flows of water into their inlet channels 26 continuously, thereby entraining and processing organisms that are present in the body of water swept by the rotating systems 18.

[0103] When a system 18 reaches the upstream side of the axis of rotation defined by the central member 66, that system 18 transitions from moving upstream against the flow 72 to moving downstream with the flow 72. When the system 18 starts to move with the flow 72 as shown to the right side of Figures 19a to 19k, the associated flap 74 is held in an active orientation extending generally transverse to the flow 72. In that active orientation, shown on system 18A in Figures 19c to 19f and on system 18B in Figure 19j and 19k, the flap 74 captures kinetic energy from the flow 72 to drive corresponding clockwise rotation of the systems 18 and the arms 64. Capture of energy from the flow 72 is enhanced by the inclination of the outer panel 82 in an upstream direction relative to the inner panel 80 of the flap 72, which therefore presents the concave side of the flap 72 in opposition to the flow 72.

[0104] The flap 74 is held in the active orientation by bearing against a radially inner one of the stops 78 on a radially inner side of the outlet channel 42, hence conveying thrust from the flow 72 to the system 18 to impart the torque that drives rotation about the central member 66. That torque sustains continuous rotation without requiring any external power source other than interaction with the incident flow 72 of water.

[0105] Conversely, when a system 18 moves against the flow 72 as shown to the left side of Figures 19a to 19k, the flap 74 pivots into a trailing passive orientation generally parallel to the flow 72. In that passive orientation, the flap 74 presents minimal resistance to upstream movement of the associated system 18. As the orientation of a system 18 relative to the flow 72 changes as the system 18 follows its circular path, the flap 74 pivots freely within its range of angular movement delimited by the stops 78 to remain aligned with the flow 72 as shown on system 18B in Figures 19c to 19f and on system 18A in Figures 19j and 19k.

[0106] Before a system 18 starts moving downstream, the associated flap 74 begins to pivot from the passive orientation into the active orientation as shown in Figures 19a to 19c. Specifically, when a system 18 transitions from upstream movement to downstream movement, the orientation of the system 18 relative to the flow 72 changes rapidly as the system 18 follows its circular path. Initially, the trailing flap 74 pivots freely relative to the system 18 but eventually the flap 74 bears against the radially inner stop 78 on the radially inner side of the outlet channel 42, as shown on system 18A in Figures 19a to 19g and on system 18B in Figures 19i to 19k. This blocks further pivotal movement of the flap 74 relative to the system 18, hence forcing the flap 74 to follow the changing orientation of the system 18 relative to the flow 72. In this way, the system 18 swings the associated flap 74 into the active orientation as the system 18 begins to move downstream, as shown by system 18A in Figure 19C.

[0107] The arrangement shown in Figures 19a to 19k uses the flow 72 to flip the flap 74 out of the active orientation as the associated system 18 nears the end of its downstream motion. Specifically, further rotation of the system 18 swings the flap 74 relative to the flow 72 until the convex side of the flap 74 is exposed to the flow 72. As shown by comparing system 18A in Figures 19g and 19h, the resulting force acting on the vanelike outer panel 82 of the flap 74 then flips the flap 74 into an intermediate orientation, bearing against the other stop 78 on the radially outer side of the outlet channel 42.

[0108] In the intermediate orientation, the flap 74 presents its convex side in opposition to the flow 72. However, the flap 74 again extends transversely to the flow 72 and so continues to capture energy from the flow 62, hence applying torque to the associated system 18 during the remainder of the downstream part of the cycle.

[0109] When a system 18 reaches the end of its downstream motion and begins to move back upstream as shown by the system 18A in Figures 19i and 19j, the associated flap 74 pivots away from the stops 78 to return to the passive orientation. The cycle of rotation then repeats, with motion of the systems 18 and of the flaps 74 driven by the flow 72.

[0110] Many other variations are possible within the inventive concept. For example, the system may also include at least one antifouling mechanism to inhibit growth of fouling on the surface of the filter. The antifouling mechanism may, for example, employ UV and / or US.

[0111] Additionally, the system could include at least one sensor configured to measure water salinity. Measuring water salinity may be used to determine the optimum depth to place the system as parasite larvae are known to thrive beneath a halocline where brackish water meets seawater.

[0112] The system could also include a plurality of impellers disposed inside and / or outside the drum. For example, an impeller could be disposed in the outlet channel downstream of the drum and another impeller could be disposed in the inlet channel upstream of the drum. Indeed, one or more impellers can be in any position or in any combination relative to the drum or other filter.

[0113] Other than directly killing or imaging the organisms, the organisms could be processed on the filter by exposing them to agents that change their adverse behaviours or that have a deleterious effect on them over time, for example to prevent the organisms from reproducing or feeding.

Claims

Claims1. A method of processing marine or water-borne organisms, the method comprising: entraining the organisms in a flow of water; trapping the organisms on a filter interposed in the flow; moving the filter, supporting the trapped organisms, relative to a direction of the flow through the filter; processing the organisms supported by the filter; and purging the processed organisms from the filter.

2. The method of Claim 1 , comprising moving the trapped organisms out of the flow before processing them.

3. The method of Claim 1 or Claim 2, comprising conveying the trapped organisms, supported by the filter, to at least one processing zone at which the trapped organisms are processed.

4. The method of any preceding claim, further comprising moving the filter supporting the processed organisms, before purging the processed organisms.

5. The method of any Claim 4, comprising moving the filter to a purge zone at which the processed organisms are purged.

6. The method of Claim 5, comprising moving the filter to the purge zone from a trap zone at which the organisms are trapped.

7. The method of Claim 6 when dependent on Claim 3, comprising moving the filter from the trap zone to the purge zone via the at least one processing zone.

8. The method of any preceding claim, comprising moving the filter in a direction transverse to the direction of the flow.

9. The method of any preceding claim, comprising moving the filter continuously.

10. The method of any of Claims 1 to 8, comprising moving the filter stepwise.

11. The method of any preceding claim, comprising purging the processed organisms by conveying an outgoing flow of water through the filter.

12. The method of Claim 11, wherein the outgoing flow comprises water of an incoming flow that carried the entrained organisms to the filter.

13. The method of Claim 12, wherein the incoming flow and the outgoing flow move in a common flow direction.

14. The method of Claim 12 or Claim 13, further comprising presenting a first side of the filter to the incoming flow and an opposed second side of the filter to the outgoing flow.

15. The method of any preceding claim, further comprising rotating the filter after trapping the organisms and before purging the processed organisms.

16. The method of Claim 15, comprising rotating the filter about an axis transverse to the flow.

17. The method of any preceding claim, comprising passing the flow through a drum that defines the filter, the flow moving in a direction transverse to a central longitudinal axis of the drum.

18. The method of Claim 17, comprising driving the flow from within the drum.

19. The method of any preceding claim, wherein processing the organisms comprises exterminating the organisms supported by the filter.

20. The method of Claim 19, comprising exposing the organisms to at least one killing mechanism.

21. The method of Claim 19 or Claim 20, comprising exterminating the trapped organisms with at least two killing mechanisms that employ ultraviolet and / or ultrasonic energy respectively in either order or simultaneously.

22. The method of any of Claims 19 to 21 when dependent on Claim 3, comprising moving the filter to a kill zone at which the processed organisms are exterminated, the kill zone being in the at least one processing zone.

23. The method of any preceding claim, wherein processing the organisms comprises capturing images of the organisms supported by the filter.

24. The method of Claim 23, comprising capturing the images when the organisms supported by the filter are out of the water.

25. The method of Claim 23 or Claim 24, comprising pausing movement of the filter while capturing the images.

26. The method of Claim 23 or Claim 24, comprising capturing the images during movement of the filter.

27. The method of any of Claims 23 to 26 when dependent on any of Claims 19 to 22, comprising assessing the captured images of the organisms and controlling extermination of the organisms in response to that assessment.

28. The method of any of Claims 23 to 27 when dependent on Claim 3, comprising moving the filter to an imaging zone at which the processed organisms are imaged, the imaging zone being in the at least one processing zone.

29. The method of any preceding claim, comprising driving the flow from upstream of the filter.

30. The method of any preceding claim, comprising driving the flow from downstream of the filter.

31. The method of any preceding claim, comprising driving the flow by movement of an external body of water relative to the filter.

32. The method of any preceding claim, comprising driving the flow and moving the filter through a body of water by thrust of the driven flow.

33. The method of any preceding claim, comprising driving the flow by moving the filter along a path through an external body of water.

34. The method of Claim 33, comprising moving the filter through the body of water along a looped path.

35. The method of Claim 33 or Claim 34, comprising driving the movement of the filter along the path by applying force from an incident flow of water.

36. The method of Claim 35 when dependent on Claim 34, comprising moving the filter alternately in upstream and downstream directions relative to the incident flow.

37. The method of Claim 36, comprising driving the movement of the filter in the downstream direction by orienting a flap in an active orientation transverse to the incident flow, the flap being movable along the path with the filter and pivotable relative to the filter.

38. The method of Claim 37, comprising presenting a concave face of the flap in opposition to the incident flow when in the active orientation.

39. The method of Claim 37 or Claim 38, comprising orienting the flap in a passive orientation aligned with the incident flow during movement of the filter in the upstream direction.

40. The method of Claim 39, comprising allowing free pivotal movement of the flap relative to the filter during movement of the filter in the upstream direction.

41. The method of Claim 39 or Claim 40, comprising flipping the flap from the active orientation to an intermediate orientation in which the flap is transverse to the incident flow but reversed relative to the active orientation.

42. The method of Claim 41 , comprising using the force of the incident flow to flip the flap into the intermediate orientation.

43. The method of Claim 41 or Claim 42, comprising presenting a convex face of the flap in opposition to the incident flow when in the intermediate orientation.

44. A system for processing marine or water-borne organisms, the system comprising: an incoming flow path configured to direct an incoming flow of water to a filter interposed in the incoming flow path, the filter being arranged to trap organisms entrained in the incoming flow; at least one processing mechanism configured to process the organisms trapped by the filter; and an outgoing flow path configured to direct an outgoing flow from the filter to entrain the processed organisms, thereby to purge the processed organisms from the filter.

45. The system of Claim 44, configured such that the outgoing flow path receives water conveyed to the filter via the incoming flow path.

46. The system of Claim 45, wherein the incoming flow path and the outgoing flow path are mutually aligned with a common flow direction.

47. The system of any of Claims 44 to 46, wherein the at least one processing mechanism comprises at least one killing mechanism.

48. The system of Claim 47, wherein the at least one killing mechanism comprises an ultraviolet emitter, an ultrasonic transducer, an infrared emitter, a laser, a roller, a scraper fresh water, desalinated water, and / or an auger press.

49. The system of any of Claims 44 to 48, wherein the at least one processing mechanism comprises at least one imaging system positioned to capture images of the organisms trapped by the filter.

50. The system of Claim 49, wherein the at least one imaging system is positioned to capture images when the organisms trapped by the filter are out of the water.

51. The system of Claim 49 or Claim 50 when dependent on Claim 47 or Claim 48, wherein the at least one killing mechanism is controllable in response to signals from the at least one imaging system.

52. The system of any of Claims 44 to 51, further comprising a housing that houses the filter and that comprises an inlet channel defining the incoming flow path and an outlet channel defining the outgoing flow path.

53. The system of Claim 52, wherein the housing is supported by a float.

54. The system of Claim 52 or Claim 53, wherein the housing is movable relative to a body of water.

55. The system of Claim 54, wherein the housing is movable through the body of water by thrust of the outgoing flow.

56. The system of Claim 54 or Claim 55, wherein the housing is movable through the body of water by a supporting frame that Is movable relative to the body of water.

57. The system of any of Claims 52 to 56, wherein the filter is movable relative to the housing from a trap zone opposed to the inlet channel to a purge zone opposed to the outlet channel.

58. The system of Claim 57, wherein the filter is movable to the purge zone from the trap zone via at least one processing zone at which the at least one processing mechanism is located.

59. The system of Claim 57 or Claim 58, wherein the filter is movable in a direction transverse to the incoming flow.

60. The system of Claim 59, wherein the filter is pivotable about an axis extending transverse to the incoming flow.61 . The system of Claim 60, wherein the filter is a drum through which the incoming flow passes to become the outgoing flow.

62. The system of Claim 61 when dependent on Claim 47 or Claim 48, wherein the drum is movable from the trap zone to the purge zone via a kill zone at which the or each killing mechanism is located.

63. The system of Claim 61 or Claim 62, further comprising an impeller disposed in the drum to drive the incoming and outgoing flows.

64. The system of any of Claims 52 to 63, further comprising an impeller disposed in the incoming flow path and / or in the outgoing flow path to drive the incoming and outgoing flows.

65. The system of any of Claims 52 to 64, wherein the housing comprises inlet vanes that extend outwardly from opposing sides of an inlet opening of the inlet channel.

66. The system of any of Claims 52 to 65, further comprising a flap that is movably mounted to and extends outwardly from the housing.

67. The system of Claim 66, wherein the flap is on a side of the housing opposed to the inlet channel.

68. The system of Claim 66 or Claim 67, wherein the flap is pivotably mounted to the housing.

69. The system of any of Claims 66 to 68, wherein the flap is offset to one side of the outlet opening.

70. The system of any of Claims 66 to 69, wherein the flap has an outboard portion that is inclined relative to an inboard portion of the flap.71 . The system of any of Claims 66 to 70 when dependent on Claim 66, wherein movement of the flap relative to the housing is limited by stops that extend outwardly from opposing sides of an outlet opening of the outlet channel.

72. The system of any of Claims 44 to 71, positioned in a body of water and mounted on, and movable through the water with, a supporting frame.

73. The system of Claim 72, wherein the frame joins to a support via a hub about which the frame can rotate relative to the support around an upright axis.

74. The system of Claim 73, wherein the support is a float.

75. The system of Claim 73 or Claim 74, being rotatable relative to the support by a flow of water that is incident on the system.

76. The system of any of Claims 73 to 75, being rotatable relative to the support by thrust of water flowing through the system.

77. The system of Claim 73 or Claim 74, wherein the support is arranged to drive rotation of the frame and the system.

78. The system of any of Claims 72 to 77 when dependent on any of Claims 66 to 71 , wherein the flap is movable to extend from the housing in a trailing direction with respect to a direction of movement of the system through the water.

79. The system of any of Claims 72 to 78, wherein the inlet channel is in a forward position and the outlet channel is in a rearward position with respect to a direction of movement of the system through the water.

80. In combination, two or more of the systems of any of Claims 44 to 79, positioned in a body of water at similar or respectively different depths.

81. The combination of Claim 80, wherein the systems are mounted on, and movable through the water with, a common supporting frame.

82. The combination of Claim 81 , wherein the systems are mounted on respective arms that extend laterally from a central member of the frame.

Images