WO2020231269A1

WO2020231269A1 - Device and method for moving marine organisms

Info

Publication number: WO2020231269A1
Application number: PCT/NO2020/050119
Authority: WO
Inventors: Jacob Hoseth; Klaus HOSETH
Original assignee: Stranda Prolog As
Priority date: 2019-05-13
Filing date: 2020-05-12
Publication date: 2020-11-19
Also published as: NO20190605A1; NO345486B1

Abstract

Device (10) for moving marine organisms (60) from a volume of water (50), characterised in that the device (10) comprises: - at least one outlet duct opening (20) connected to an outlet duct (22) which carries water into the water volume (50) where the water creates a flow field and - adjacent the outlet duct opening (20), at least one suction duct opening (30) is connected to a suction duct (32) which pulls water and marine organisms (60) out from the flow field created by the outlet duct (22).

Description

Device and method for moving marine organisms

Field of the invention

The present invention relates to a device for moving marine organisms from a volume of water, as well as a method for moving marine organisms.

Background of the invention

The background of this invention is a need in the aquaculture industry to improve the collection of fish from a net cage. Today's method consists of pushing the fish together and lowering a suction funnel into the net cage to suck up the fish. The challenge is that the fish must be forced quite together tightly in order to have sufficient collection capacity. Animal welfare can be improved if you do not need to force the fish together as tightly as today.

Fish absorb oxygen over gills, and they usually have two methods of providing water circulation across the gills. Either the fish swim with an open mouth through the water or they use so-called mouth pumping. Mouth pumping occurs when the fish opens the mouth to take in water in front and then closes the mouth while the water in the mouth is pushed further across the gills.

Salmon fish use most energy when using mouth pumping and therefore prefer to provide water to the gills by swimming with an open mouth. The fish have hair-like sensors along the centreline which they use to find out how the water flows along the body.

The movement response of an organism which lives in water or air is referred to as reotaxis. Organisms with positive reotaxis when exposed to a stream, will preferably move toward the stream, while organisms that have negative reotaxis will preferably move with the stream. Salmonids, for example, have positive reotaxis and will preferably swim against a current to which they are exposed.

Description of prior art

A common method of collecting fish today is to lower a collection funnel into the water, for example, down into a farming net cage. Then the water from the net cage is sucked into the collection funnel to be transferred to, for example, a well boat. As long as the fish has positive reotaxis, which is the case for salmonids, for example, the fish will stand up to the current and swim away from the collecting funnel. The fish must then be very tightly constricted so that they can be sucked up into the collecting funnel, which is unfortunate in view of the stress of the fish and general animal welfare.

Another disadvantage that can often be seen using traditional collecting funnels with suction is that a standing vortex is formed in front of the funnel opening which sucks air into the collecting funnel.

This disadvantage is also present in US 20180206458A1. This is despite the fact that an apparatus with a suction pipe is shown in combination with an outward current. Because the passage is formed in separate rods and the distance between the suction pipe and the outward flow is too large, a standing vortex which draws air from the surface and down into the suction pipe will also occur. The distance between the suction pipe and the outward flow also leads to that there will be a zone between the suction pipe and the outward flow where the water will be more or less still. This can lead to the fish stopping, which in turn will lead to reduced capacity. The publication shows a fish transfer device for directional positioning of the fish that enter into a fish transfer pump which reduces damage, stress and promotes sea lice removal when connected to a Coanda effect fish transfer pump. The apparatus utilises a collection structure constructed from a funnel-shaped passage made of individual rods. A manifold is placed along an outer surface of the intermediate rods to guide a flow of water through the passage in a predetermined position. The fish approaching the apparatus are naturally attracted to the outward flow of water passed the ring frame and come into the passage as they want to swim against the current. When the fish pass the manifold, the fish are exposed to suction caused by the transfer pump and are drawn into the suction pipe for transfer.

NO310391 describes a method and device for moving marine organisms, especially live fish, for example, from a net cage to a well boat or vice versa, where an arch shaped (U-shaped) tube is mounted between the net cage and the cargo hull from which the transfer shall go to or from. Upon pressure change, a real or virtual level deviation (A) is established between the sea level in the net cage and the level in the room so that a flow of water is formed through the tube. By means of a water pump, it is ensured that the amount of water in the room is kept constant within certain limits.

N031461 1 describes a pump for live fish, comprised of a pressure tank with an inlet tube with a valve for fish and water from a pool, for example, a well boat; an outlet tube for fish and water to a drain with a return tube for water. Unique to this invention are the following: that the return tube runs back to the pressure tank to form a circuit which is open at the grid; a pump in the return tube for return of water from the grid to the pressure tank so that the pump can pressurise the water and circulate the water and fish in the pressure tank, preferably in a single direction running circuit.

US2683969 relates to fish ladder structures and a new method for guiding migrating fish into the fish ladder and over a pond structure or another barrier.

NO310751 describes a device and method of deliberate orientation of fish based on instinctual reactions of the fish to ensure that when the fish leave a vessel they do so with common anatomical orientation, such as with the head first and the back up.

The vessel is partially filled with water and has at least one outlet. A stream of water away from the vessel outlet is produced, which causes the fish which are introduced into the vessel to orientate themselves with the head first in the flow direction. In addition, in the water in the vessel, an environment that is disturbing to the fish can be created, thereby causing the fish to want to leave the vessel. In order for the fish to be able to leave the vessel they must actively swim towards and through the outlet opening. After the fish have left the vessel, they can be subjected to any number of fish handling operations such as automatic vaccination, marking, sorting and/or counting, whereby it may be advantageous to have the fish delivered at a given location at high speed and with the same orientation.

N0337564B1 describes a table for distribution of fish for anesthetising, where the table includes: a reservoir for holding fish and water; an inlet for bringing fish into the reservoir; an overflow to allow fish to pass from the reservoir; a slide for distributing fish after they have passed the overflow, as the table comprises a water flow device for supplying water to the reservoir, where the water flow device is orientated to supply water in a direction away from the overflow.

As other prior art, US 4743742 A can be mentioned.

Objects of the present invention

An object of the invention is to improve animal welfare in the collection and movement of marine organisms.

An additional object is to reduce the stress for marine organisms that shall be collected.

Yet another object is to improve animal welfare for the fish during collection of live fish by reducing the need to crowd fish tightly for collection.

Yet another object is to reduce the stress for the fish during the assembling process by reducing congestion and increasing the oxygen supply to the fish before and during the assembling.

Another object is that the fish that are collected shall be orientated alike, for example, in that all fish which are collected are orientated with head first, for example, to enable a subsequent automated slaughter process. A possible object is also to enable the sorting of marine organism species according to swimming ability.

Another object is to be able to collect and remove from the water volume parasites that come off the fish during a collection operation.

Another object of the invention is to avoid the creation of a suction vortex where air is sucked down from the water surface and into the channel through which marine organisms are led.

Yet another object of the invention is to avoid zones in the water in front of a collection opening where fish will stop and reduce the efficiency of assembly.

Summary of the Invention

One or more of the aforementioned objects are attempted to be solved by means of a device for moving marine organisms from a volume of water. The device

comprises:

- at least one outlet duct opening connected to an outlet duct which leads water into the water volume where the water creates a flow field and

- adjacent the outlet duct opening is at least one suction duct opening connected to a suction duct which draws out water and marine organisms from the flow field created by the outlet duct.

The device can comprise a housing part where the outlet duct and the suction duct are connected and the housing part defines the outlet duct opening and the suction duct opening.

The outlet duct opening can be covered with a barrier that prevents marine organisms from passing, while water can pass.

The barrier that can cover the outlet duct opening can be selected from the group: grid, grille and net. The barrier that can cover the outlet duct opening can be inclined towards the suction duct opening to guide marine organisms that swim against the stream towards the suction duct opening.

The suction duct opening can be arranged above the outlet duct opening.

The marine organisms that are being moved can be fish.

The marine organisms can be salmonids.

The marine organisms can be marine organisms with positive reotaxis.

The area of the suction duct opening can be small enough so that the average marine organism in the volume of water which has swum up to the suction duct opening slows the flow from the outlet duct opening to the suction duct opening, and thereby ensures that the flow forces that transport the organism into the suction duct opening to increase, the area of the suction duct opening can be preferably 2-3 times larger than the average marine organism.

The device can be comprised of a pump for supplying water through the outlet duct.

The amount of water supplied through the outlet duct can be adjusted.

The suction in the suction duct can be provided by means of the group consisting of: underpressure loading of well boat, vacuum pump, CWC pump, centrifugal pump and ejector pump.

The strength of the suction in the suction duct can be adjusted.

The outlet duct opening can be shaped like a funnel.

The outlet duct opening can enclose the suction duct opening. The volume of water can be enclosed by a net cage.

The outlet duct opening can be provided in the net wall of the net cage.

The suction duct opening can be provided in the net wall of the net cage.

The device can be mounted in a well boat where the water volume is a well in the well boat.

The water flow from the outlet duct opening can help to circulate the water volume.

The device can be equipment with several suction duct openings and where each suction duct opening is associated with a suction duct.

The housing part can be fitted with one or more additional suction openings to draw water into the suction duct from an area outside the flow field.

The marine organisms can be forced together in front of the suction duct opening with the help of a filter cloth, and the filter cloth is attached to the housing part so that marine organisms cannot pass between the filter cloth and the housing part, the filter cloth is suitable for catching parasites that are separated from the marine organisms during collection.

The marine organisms can be forced together in front of the suction duct opening by means of a net, and the net is attached to the housing part so that marine organisms cannot pass between the net and the housing part.

Side bar elements can be arranged, projecting from each side of the housing part to prevent marine organisms from entering the flow field in front of the side openings.

One or more of the aforementioned objects are solved with the help of a method of moving marine organisms from a volume of water, characterised in that a device immersed in the volume of water is used and that the method comprises the steps of:

- crowding marine organisms in a limited volume of water,

- exposing the marine organisms to a countercurrent field from an outlet duct opening that the marine organisms instinctively want to orientate towards and swim towards,

- influencing the marine organisms to move forwards countercurrent to a suction duct opening associated with a suction duct to draw a volume of water out of the flow field, and

- sucking the marine organisms approaching the suction duct opening into the suction duct that directs the marine organisms away from the volume of water.

Description of figures

Preferred embodiments of the invention will now be described in more detail with reference to the accompanying figures, in which:

Figure 1 shows a section of a possible embodiment of the device

Figure 2 shows a section of a possible embodiment of the device

Figure 3 shows a possible embodiment of the device in cross-section

Figure 4 shows a possible embodiment of the device in cross-section

Figure 5 shows an enlarged section of the device.

Description of preferred embodiments of the invention

For the sake of simplicity, the term fish 60' is used in the description. Flowever, it should be understood that the invention is not limited to fish 60', as the invention will also be applicable to other marine organisms 60 with positive reotaxis. The term fish 60' is used in the description to simplify and make the text easier to read. Since some of the advantages of the invention are dependent on the that the organisms that shall be collected have a positive reotaxis, then it is meant by marine organisms 60 only marine organisms with positive reotaxis.

When water or water volume is referred to, fresh water, salt water and brackish water are included in the term water or water volume.

The invention relates to a device 10 for moving and/or collecting marine organisms 60 such as fish 60' from a water volume 50. The device can be comprised of at least one outlet duct 22 which can be lowered into a water volume 50. The outlet duct carries water into the water volume 50 through at least one outlet duct opening 20. In connection with the outlet duct (s) 22, there are one or more suction ducts 32 with one or more suction duct openings 30 which draw water into the suction duct (s) 32.

The suction in the suction duct 32 can be established in that the tube or duct is connected with a region of lower pressure further downstream. Examples:

underpressure loading of well boat, vacuum pump, CWC pump, centrifugal pump, ejector pump. The flow of water in the outlet duct 22 can be established with a pump 80 or the means which are obvious to a person skilled in the art.

The position/direction indication above is used in the text. By indicating that something is above or below something else, it is talking about relative position on the vertical axis as it would normally be used in daily speech.

Figures 1 and 2 show a possible embodiment in which the outlet duct 22 and the suction duct 32 go over into a housing part 40 which defines, on the inside, an outlet duct opening 20 and a suction duct opening 30. The outlet duct opening 20 can be covered by a barrier 76, such as a grille, a net or a grid. The barrier 76 can, as shown in figure 1 , tilt towards the suction duct opening 30 that lies above the outlet duct opening 20 and by this, lead the fish 60’ towards the suction duct opening 30. The suction duct opening 30 can be divided into several sections with dividing elements 42 to prevent that fish 60’, which are sucked into the suction duct opening 30, manage to turn around and swim out of the suction duct opening 30.

The volume flow out of the outlet duct 20 can be greater than the volume flow into the suction duct opening 30. This will result in a net flow of water out of the housing part 40 and into the water volume 50. Parts of the water which are supplied through the outlet duct 22 will, in a zone around the suction duct opening 30, change the direction towards the suction duct opening 30. The flow through the outlet duct 22 and the suction duct 32 can be adjustable. In figures 3 and 4 there are arrows indicating flow directions and showing the flow field.

Fish 60' with positive reotaxis such as, for example, salmonids will instinctively lie with their head against the stream and swim to get water across the gills. Salmonids in a farming net cage will thereby start to swim with the head in towards the outlet duct opening 20. By forcing fish 60' together in the area in front of the outlet duct opening 20, some fish 60' will eventually instinctively swim into the outlet duct opening 20 if disturbed by the fish 60' behind. Tests conducted have shown that salmonid fish do not readily detect changes in flow direction at the suction duct opening 30. One theory is that this can have something to do with the centreline which feels the flow direction not extending beyond the head of the fish. Therefore, the fish 60’ does not change direction until it is too late to avoid being sucked into the suction duct 32.

Figure 5 shows, in an enlarged section, the flows around a fish 60' which is about to be sucked into the suction duct opening 30. When the head of the fish 60' enters the area where the flow lines bend towards the suction duct opening 30, the head will partially seal the suction duct opening 30, at the same time the turning point of the flow will be moved behind the fish 60'. This effect comes from the fact that the fish 60' blocks some of the flow area. This helps to overwhelm the fish 60' which, at one moment, exists in a countercurrent field which, due to the presence of the fish 60', changes to a co-current field and thus the fish 60' is sucked in before it can react. This effect is enhanced by the geometry around the openings 20/30. In an

independent suction opening out of an adjacent countercurrent field, this effect will not be present to the same degree.

In order for a change in the flow direction which shall overwhelm the fish 60’ then it is an advantage that there is a flow out from the device 10 and that this countercurrent field runs so close to the suction duct opening 30 as possible before the flow turns towards the suction duct opening 30. The suction duct 32 ought thereby to avoid giving the fish 60’ co-current in front of the openings 20/30 and, in the main, suck in water that flows out from the outlet duct opening 20. This can be unfortunate if, in some of the area in front of the openings 20/30 there is flow towards the device 10, as the fish 60’ will not swim towards the device in the area, and this will in turn lead to a reduced capacity.

As mentioned earlier, the outlet duct opening 20 can be covered by a barrier 76. The barrier can be used in combination with said embodiments, but also other

embodiments. The barrier can be in the form of a grid, a grille, a net, a seine, or any other barrier 76 which is familiar to one skilled in the art. The premise is that water must be able to pass the barrier 76, but the fish 60' which one attempts to collect cannot pass the barrier 76. This is to prevent that the fish 60' shall reach far into the outlet duct 22, which is not necessarily desirable. The barrier 76 can also have the function of guiding the fish 60' towards the suction duct opening 30.

Tests with the device 10 have recently shown that by arranging side closing elements on each side of the openings 20,30, then one can further optimise the collection of fish 60’. The side closure elements are intended to prevent fish from entering the flow field in front of the openings 20,30 from the side. It has been observed that fish can come swimming from the side into the flow field that comes out of the device 10. Fish 60’, which come from the side, are pushed by the current towards fish which are facing the device and disturb the fish which is about to swim in towards the openings 20, 30. The side bar elements can be in the form of plates which are generally vertical at an angle from the device 10. Other designs of side bar elements such as grids, nets or perforated boards can also be used. In a preferred embodiment, the side bar elements stand vertically in the water protruding from the device 10, one on each side, and so that the distance between the side bar elements is tapered towards the housing part 40. Barriers can also be arranged below and/or above the current out from the housing part 40 to prevent that fish come sideways into the stream from above or below, although this is a minor problem. If barriers are provided both above, below and on the sides, the barriers can form a funnel-shaped opening. The side bar elements are not shown in the figures. By in from the side or from the side, is meant here that fish 60^' enters the flow field from a direction that is more or less normal (90 degrees) to the flow direction.

A net 78 or a filter cloth 78^' can be used to collect the fish 60' in front of the outlet duct opening 20. The net 78 can be attached to the housing part 40. A garland or flange-like collar (not shown in the figures) can be provided on the housing part 40 around the openings 20, 30 to provide fastening options for a net 78 or a filter cloth 78’. Alternatively, it is conceivable that the device 10 with outlet duct 22 and suction duct 32 is completely or partially fitted in the net wall of a net cage 100 in a farming facility, or in the bulkhead of a tank.

The net 78 can thus be used to gradually push fish 60' together in front of the outlet duct opening 20.

A filter cloth 78' can be used instead of a net 78 to crowd fish 60'. By using a filter cloth 78', one can collect parasites such as salmon lice that are released from the fish 60' during collection. After the fish are collected through the suction duct 32, the flow in the outlet duct 22 can be reduced and or the suction in the suction duct 32 is increased so that parasites collected on the inside of the filter cloth 78' can be sucked out to eventually be destroyed.

In one possible embodiment, the device 10 is mounted in a well boat for moving fish 60' between wells in the well boat, or from the well boat to another location. The device 10 can, for example, be mounted in one of the bulkheads of a well in the boat.

How the outlet duct 22 and suction duct 32, with associated outlet duct opening 20 and suction duct opening 30 are arranged in relation to each other and in relation to the barrier 76 and how one or more nets 78 or filter cloths 78’ are used in relation to the device 10, can vary in a number of different ways. For example, the suction duct opening 32 can be enclosed by an outlet duct 22. It can be that a suction duct 32 with a suction duct opening 30 is arranged in the centre of a funnel-shaped outlet duct opening 20.

Alternatively to a barrier 76, a constriction in the area of the outlet duct 22 can be used to prevent fish from swimming far into the outlet duct 22. A narrowing of the flow area will increase the flow speed and thus fish will not be able to swim any longer against the flow. Such a solution can, for example, be used in conjunction with a funnel-shaped outlet duct 20 where a suction duct opening 30 is provided within the outlet duct 20.

In order to create the desired flow field into the water volume 50, plates may be arranged inside the outlet duct 22 near the outlet duct opening 20 to direct the flow of water in the desired direction and to ensure that the outflow speed is approximately equal across the entire area of the outlet duct opening 20 in those cases where this is desirable.

The volume which is supplied through the outlet duct 20 and the volume which is sucked out through the suction duct 30 can be changed and be adjusted to obtain an optimum effect under the current conditions and for the particular type of fish 60'.

The area of the suction duct opening 30 will also affect how well the device will work. An area of 2-3 times the largest cross-sectional area of the fish 60' is believed to have a good effect in relation to that the fish 60' will be sucked quickly into the suction duct 32 when the head of the fish is in the suction duct opening 30 or immediately in front of the suction duct opening 30. But a larger or smaller area on the suction duct opening can be necessary to provide the best possible effect and maintain animal welfare. The shape and swimming ability of the fish as well as other factors will be able to affect this.

Since all fish 60' shall enter the suction duct 20 with head first, the device 10 is well suited for use where it is desirable to simultaneously orientate the fish 60' for a subsequent processing step. It can be that the fish is collected for slaughter and then it would be an advantage if the fish 60' are orientated ahead of a subsequent automated slaughter process.

The device can also contribute to sorting fish 60' in that flows in the outlet duct 22 and the suction duct 32 are adjusted. For example, it can be envisaged that fish 60' which are sick or injured will not be able to swim against the current until they are sucked into the suction duct 32. Similarly, it is possible to avoid that cleansing fish with a weaker swimming ability are collected together with, for example, salmonids.

It is also conceivable that the device 10 has several suction duct openings 30 and that each suction duct opening 30 is connected to each suction duct 32.

Furthermore, the device 10 can be included as part of a system for creating circulation in a net cage 100 and can thus replace all or part of such a system. In such a situation, it is conceivable that there could be flow through the outlet duct 22 when no fish are being collected. Then the suction duct 32 can be closed.

The device 10 can also be wholly or partially fixed in the net wall of a net cage 100 or in a vessel or other container where, from time to time, it is necessary to collect fish 60'. It is then conceivable that pumps and large parts of the outlet duct and suction duct can only be switched on when needed.

In that the suction duct opening 30 is arranged in connection to an outlet duct opening 20, one reduces or eliminates the problem of suction duct 32 sucking or removing air from the surface which is a problem with today's solutions.

By the openings being adjacent, it is meant that the openings are so close to each other that the suction duct opening 30 mainly sucks in water flowing out of the outlet duct opening 20. Thus, the openings 20, 30 do not necessarily need to be

completely adjacent, but in the immediate vicinity. Of course, it is difficult to say with great certainty that it is purely water from the outlet duct 20 that is sucked in because of the complexity of the flow patterns that can occur, but by positioning the openings 20, 30 close to each other, and by adjusting the flow direction and amount in the suction duct 32 and the outlet duct 22, one can achieve that, in the main, it is water from the outlet duct 22 which is sucked in. In one possible embodiment, the device 10 can be fitted with a number of additional suction openings 72 on top of the housing part 40 (as shown in figures 1 and 2) and which can draw in water from outside the flow field. It can be desirable that the through-flow of water through one or the additional suction opening (s) 72 can be adjusted and closed completely if desired. In particular, in cases where a filter cloth 78' is used, it can be desirable to draw water from the outside of the filter cloth 78' in addition to water from the flow field on the inside of the filter cloth 78'. The one or the additional suction opening(s) 72 can be covered by a barrier such as a grille, grid or net.

Claims

1. Device (10) for moving marine organisms (60) from a volume of water (50),

- at least one outlet duct opening (20) connected to an outlet duct (22) which leads water into the water volume (50) where the water creates a flow field and

- adjacent the outlet duct opening (20), at least one suction duct opening (30) is connected to a suction duct (32) which pulls out water and marine organisms (60) from the flow field created by the outlet duct (22).

2. Device (10) for moving marine organisms (60) according to claim 1 ,

duct (22) and the suction duct (32) are connected and wherein the housing part (40) defines the outlet duct opening (20) and the suction duct opening (30).

3. Device (10) for moving marine organisms (60) according to claim 1 ,

prevents marine organisms (60) from passing, while water can pass.

4. Device (10) for moving marine organisms (60) according to claim 3,

selected from the group: grid, grille and net.

5. Device (10) for moving marine organisms (60) according to claim 3,

towards the suction duct opening (30) to guide marine organisms (60) which swim countercurrent to the suction duct opening (30).

6. Device (10) for moving marine organisms (60) according to claim 1 , characterised in that the suction duct opening (30) is arranged above the outlet duct opening (20).

7. Device (10) for the movement of marine organisms (60) according to claim 1 , characterised in that the marine organisms (60) that are moved are fish (60').

8. Device (10) for moving marine organisms (60) according to claim 1 , characterised in that the marine organisms (60) are salmonids.

9. Device (10) for moving marine organisms (60) according to claim 1 , characterised in that the marine organisms (60) are marine organisms with positive reotaxis.

10. Device (10) for moving marine organisms (60) according to claim 1 ,

the average marine organism (60) in the water volume (50) which has swum to the suction duct opening (30) slows the flow from the outlet duct opening (20) to the suction duct opening (30), and thereby ensures that the flow forces that transport the organism (60) into the suction duct opening (30) increase, the area of the suction duct opening being preferably 2-3 times larger than the average marine organism (60).

1 1. Device (10) for moving marine organisms (60) according to claim 1 ,

through the outlet duct (22).

12. Device (10) for moving marine organisms (60) according to claim 1 ,

can be adjusted.

13. Device (10) for moving marine organisms (60) according to claim 1 , characterised in that the suction in the suction duct (32) is provided by means of the group consisting of: underpressure loading of well boat, vacuum pump, CWC pump, centrifugal pump and ejector pump.

14. Device (10) for moving marine organisms (60) according to claim 1 , characterised in that the strength of the suction in the suction duct (32) can be adjusted.

15. Device (10) for moving marine organisms (60) according to claim 1 ,

16. Device (10) for moving marine organisms (60) according to claim 1 , characterised in that the outlet duct opening (20) encloses the suction duct opening (30).

17. Device (10) for moving marine organisms (60) according to claim 1 , characterised in that the water volume (50) is enclosed by a net cage (100).

18. Device (10) for moving marine organisms (60) according to claim 17, characterised in that the outlet duct opening is arranged in the net wall of the net cage (100).

19. Device (10) for moving marine organisms (60) according to claim 17,

net cage (100).

20. Device (10) for moving marine organisms (60) according to claim 1 , characterised in that the device is mounted in a well boat where the water volume (50) is a well in the well boat.

21 . Device (10) for moving marine organisms (60) according to claim 1 ,

circulation in the water volume (50).

22. Device (10) for moving marine organisms (60) according to claim 1 ,

number of suction duct openings (30) and each suction duct opening (30) is connected to a suction duct (32).

23. Device (10) for moving marine organisms (60) according to claim 2,

characterised in that the housing part (40) is fitted with one or more extra suction openings (72) to pull water into the suction duct (32) from an area outside the flow field.

24. Device (10) for moving marine organisms (60) according to claim 2,

characterised in that the marine organisms (60) are forced together in front of the suction duct opening (30) by means of a filter cloth (78^') and that the filter cloth (78^') is attached to the housing part (40) so that marine organisms (60) cannot pass between the filter cloth (78^') and the housing part (40), the filter cloth (78^') is suitable for capturing parasites that are separated from the marine organisms (60) during the collection.

25. Device (10) for moving marine organisms (60) according to claim 2,

characterised in that the marine organisms (60) are forced together in front of the suction duct opening (30) by means of a net (78) and the net is attached to the housing part (40) so that marine organisms (60) cannot pass between the net (78) and the housing part (40).

26. Device (10) for moving marine organisms (60) according to claim 2,

characterised in that side-locking elements are arranged, projecting from each side of the housing part (40) to prevent marine organisms (60) from entering the flow field in front of the openings ( 20,30) from the side.

27. Method of moving marine organisms (60) from a water volume (50),

characterised in that a device (10) submerged in the water volume (50) is used and the method comprises the steps of:

- crowding marine organisms (60) into a defined volume of water,

- exposing the marine organisms (60) to a countercurrent field from an outlet duct opening (20) that the marine organisms (60) instinctively want to orientate to and swim towards,

- influencing the marine organisms (60) to move forward countercurrent to a suction duct opening (30) adjacent to a suction channel (32) to draw a volume of water out of the flow field, and

- sucking the marine organisms (60) that are approaching the suction duct opening (30) in the suction duct (32) which leads the marine organisms (60) away from the volume of water.