The present invention relates to a device for delousing aquatic organisms, such as fish, in a floating fish farming installation, comprising a floating, at least partially submersible module, where the module is arranged to be placed between two cages and comprises at least one inlet channel and one outlet channel for letting in fish and releasing fish, respectively.

The fish farming industry experiences great challenges from infections and problems with attacks from lice on 'the fish. Up until now the delousing agent and the problems with lice have been treated through the feed, but lately, it has been found that lice are building up a resistance to slice (feed with delousing agent). At the same time with today's solutions, the fish are very exposed to stress during the operations of moving, sorting and delousing. The operations are often complicated, take too much time and are costly for the farm operators.

Today, large well boats are used for the transport, sorting and delousing. This is an expensive solution, but is also a source for spreading of disease as the boats are used for transport of smolt and fish for slaughter everywhere, and travel through zones with several fish farming installations. In addition, there are complicated and extensive procedures for cleaning and disinfecting ^' of tanks and equipment on board.

The well boats are high, heavy and long, and particularly susceptible to currents and wind which make it difficult in many cases to manoeuvre and moor in a position between two or more cages in a fish farming installation where the cages are close together. The well boats are based on pumping and suction in the form of over pressure and underpressure. In many cases it has been found to cause damage to the fish and expose them to stress and lay them open to more disease.

In particular, the fish are subjected to stress during delousing, when the operations are carried out quickly.

Another presently tried method is based on tarpaulins being placed around the net cages completely, or partially, as a skirt. Thereafter, large amounts of chemicals that are poured in, leak out into the surrounding environment as the tarpaulins are not watertight. This ensures that the method is uneconomic and inefficient, at the same time as the effect is not certain and the tarpaulins are subjected to large forces from the currents.

Wrasse that feed on the lice has also been tried. The problem is' that this represents a risk to the nets if there is not enough lice in the nets as the wrasse feed on the growth on the nets.

In addition, there is not sufficient wrasse on the market for this to be a satisfactory solution in the near future.

From prior art, attention is given to WO9417657, among others, which relates to two cages that are tied together with a horizontal channel that contains equipment to remove parasites from fish which are moved from one cage to another cage. The equipment that is used for the removal of parasites is sound waves that make the parasites let go of their host fish, and where free parasites are filtered away.

WO9941976A2 shows a system for treatment of fish in a medicinal bath of liquid which is recirculated and dosed with medications. A floating tank is used, which is placed in a volume of water from which the fish are collected and led back to after the treatment. The liquid that follows the fish from the normal environment and from the liquid bath is separated from the fish. The tank that is used is circular and the fish are driven from one cage and into the tank through an inlet, whereupon the fish are treated in different steps, and thereafter released out into the same cage the fish came from through an outlet in the tank.

NO303171 Bl shows equipment and a method for removal of parasites on salmon, where the fish are led into a stream of water and' the fish are subjected to water sprays from several nozzles that are placed in a ring adjoining 'and inside a pipe through which the fish are led.

Norwegian Patent application NO841867 shows the use of Shockwaves for removal of parasites from salmon. US 4,086,875 relates to the sorting of fish under water where a sorting grid is used which the fish are driven or forced through.

With the present invention, one aims to solve the problems with a more efficient, compact and environmentally friendly, reliable and gentle moving and delousing of the fish, and delousing of fish in a fish farming installation. Furthermore, one aims for a homogeneous mixing in of the delousing bath agent for the fish, and where transport takes place at the same time as the delousing is carried out. Furthermore, it shall preferably be a continuous process.

A further aim of the present invention is to provide a mobile unit which, in the main, can be moved of its own accord between different cages in a fish farming installation. The above mentioned objects are reached with the device as defined in the independent claim 1, ^" while alternative embodiments are given in the dependent claims.

According to the present invention a device is provided for delousing .of aquatic organisms, such as fish, in a floating fish farming installation comprising a floating, at least partially submersible module, where the module is arranged to be placed between two cages and comprises at least one inlet channel and one outlet channel for letting in fish and releasing fish, respectively, characterised in that the module furthermore encompasses means for homogeneous dosing of a chosen delousing agent in a controlled way to a water basin in the module, and is mixed with water in the basin, at the same time as the organisms are transported through the basin, so that lice which are removed from the fish in the basin let go and sink down towards a bottom zone, whereupon the lice are arranged to be removed from the basin.

The basin can be constructed as a horizontal chute with a flat bottom and side walls, to move the fish horizontally with the help of a movable grid and to move the fish in groups driven in step with the intake of fish from the cage. The grids can be made to move in several directions and are positioned to restrict the fish into several sections in the basin in a controlled way.

The grid can be equipped with a thin-meshed net to collect small particles such as lice and lice eggs to prevent these from being transported further to the next cage with the risk of transferring the infection and hatching of new lice larvae. At its lower end the grid can be equipped with a brush and the grid can comprise a lower part that can be raised.

The module can be a mobile unit and comprise equipment to 5 manoeuvre the module in a fish farming installation in a completely or partially independent way in that the module is equipped with means for positioning and ballasting, respectively, with the help of one or more pumps and one or more propellers or water-jet motors. -0 ^{' ' '}

Furthermore, the module can comprise one or more fender arms arranged to keep a fixed distance to the cages, with the inlet and outlet • channels being in the correct position, vertically and horizontally, to be able to be connected to5 the cages.

It is an advantage to suck up, or pump up lice to the upper deck of the module from a collecting chute and through a pipe to be collected and separated in, for example, a filter0 box or container and where the water and delousing agent mixture can be led back to the basin.

To improve the cleaning, the inlet channel can be equipped with an ejector or a spray appliance that lets fish through,5 at the same time as the surface of the fish is subjected to controlled, intensive sprays of water with a source from, for example, a pump and supply pipe, where the sprays are at an angle and arranged to get the lice to completely, or partially, let go of the fish, and where the fish and lice0 follow the stream of water caused by the injector and end up in the basin.

Furthermore, the module can be equipped with measuring instruments, for example, for oxygen, counting of fish and5 . lice, measuring the weight of the fish in the outlet channel, and that the whole process can be logged, controlled and monitored.

To ensure a controlled oxygenation of the fish, to be able to increase the capacity and guard against mortality, the module can comprise several horizontally orientated oxygen pipes which are perforated in the longitudinal direction and which are arranged at the bottom of the module.

The invention shall now be described in more detail with the help of an embodiment example, in which:

Figure 1 shows a device according to the invention placed between two cages.

Figure 2 shows in more detail the device shown in figure 1, where the one wall is removed.

Figure 3 shows a floating module, corresponding to the one shown in figures 1 and 2.

Figure 4 shows the module shown in figure 3 viewed from above . Figures 5a and 5b show a grid for use in the device according to the invention.

Figure 6 shows the module being moved.

Figures 1 and 3 show a floating module 10 for placing between two cages 12, 14. The module can be mobile and have its own equipment for propulsion.

As shown in the figures, an embodiment example of the module 10 according to the present invention can be comprised of a horizontal chute that constitutes a water basin 22 with a bottom 24, where the fish continuously, or batch wise, are transported along in the basin 22 with the help of one or more carriages or grids 20 that are operated through a controlled movement. These can be driven backwards and forwards, and the grid can be raised so that the fish can ■ be transported at the same time as a new batch is brought in, and the fish are, at the same time, bathed in a delousing agent, while the transport takes place in a particularly gently way, and for the system to be able to have an efficient delousing effect with a large capacity.

Furthermore, the module 10 can be equipped with one or more horizontal fenders 34 and 36 that are arranged on the outside on either side, for example, in combination with one or more struts, and which shall keep the module 10 a fixed distance from the cages, preferably in that these lie against the cage collars of the cage 12, which is to be emptied, and the cage 14, or more cages that shall be filled with fish after the delousing and/or sorting.

An upper deck 32 can serve as a footbridge and areas for means required to manoeuvre and moor the module 10 between the cages 12,14 and also for monitoring and control of the fish, and all the operations involved in moving, sorting and delousing of the fish. The grid 20 can also be equipped with a footbridge 32a.

The module 10 can comprise one or more capstans/winches for pulling lines in one or more directions and thereby to lock the module 10 securely before the operation of moving the fish starts. In addition, another positioning possibility with propellers or water-jet solutions can be used, arranged on the underside or out side of the module 10 and possibly connected directly into a buoyancy chamber.

In this way, the module 10 can be self sufficient and be manoeuvred and moored in all directions on its own accord without help from working boats. One can visualise that more than two cages can easily be connected to the system in the case of moving and sorting of fish from a cage. A third manoeuvring possibility so that the module shall be positioned in a reliable and quick way is vertical positioning with the help of a ballast pump. Here, one can alternate between filling the basin 22 or emptying and refilling the ballast tank.

After the module 10 is positioned securely between the inlet cage 12 and the delivery cage 14, the transport of the fish into and out of the module 10, remains. A casting net can, for example, be used to move the fish towards the module 10 in the cage 12, or other known methods to move the fish -in a cage.

After having completed the mentioned operations, the cage 12 can be opened by opening the net towards the inlet channel 16 and the moving of the fish in the cage 12 with the casting net can then start. Fish can then swim in through the inlet channel 16 via, for example, an inlet gate set up vertically in the channel 16 to end up in the water basin 22. Then, the outlet channel can be closed, but not necessarily, which shall be explained in detail later. The gate in the inlet 16 is thereafter closed after enough fish have been moved in one round into the water basin 22.

A number of grids 20 can be set up in the water basin 22, as shown in figure 2, so that several volumes are provided for batch wise forward movement of fish between the inlet and the grid, between the grids and between the grid and the outlet. Furthermore, the grid 20 can, as shown in the figures 5a and 5b, comprise an upper and a lower part 20a, 20b that can be displaced horizontally in relation to each other. The grid 20 can thereby let fish through by raising the lower part 20b in relation to the upper part 20a, and can also function as a barrier against outflows of inflows.

In this context, it shall be noted that the fish can be brought into the module 10 through the inlet 16 as explained and that the fish can be driven back to the same cage through the inlet 16, which in this case functions as an outlet. Thus it will be possible to raise the raiseable grids 20 to be driven adjoining the original outlet 18, be lowered and thereafter drive the fish back towards and out through the inlet 16.

In the figures 5a and 5b the grid 20 is shown to be equipped with a fish net 26 to collect eggs released from fertile female lice, to prevent eggs being transported into the next cage and that these are hatched to new, fresh lice larvae. The grid 20 can furthermore be equipped with a brush 28 to ■ sweep away lice and other parasites or dirt, for removal from the basin 22.

At the bottom 24, several horizontally orientated oxygen pipes 38 are also shown, that are perforated in the longitudinal- direction and which shall ensure a controlled . oxygenation of the fish so that the capacity can be increased and safeguard against mortality. Sensors can

^' register the oxygen level and thereby control residence time while the delousing agent is working. The supply of oxygen is primarily carried out at the same time as the fish are exposed to the delousing agent.

The amount of fish can be controlled visually from the deck or with a counting apparatus at the inlet or the outlet., In this way it takes a very short time for a considerable number of fish to be moved into the module 10 in a reliable and gentle way without pumping and stress for the fish.

The embodiment example shows delousing of the fish in the basin 22 where a tank with delousing agent can be placed on the deck, which doses a controlled amount of delousing agent into the water basin 22. The method for moving the fish inside the basin and also the delousing time can therefore be carried out in a reliable, gentle and quick way, which makes the invention well suited to fish farming installations with storm cages and a large biomass.

The supply of delousing agent, for example, hydrogen peroxide, is environmentally friendly and is the most effective against lice. According to the invention all types of delousing agents can be used and at different concentrations according to the effect wanted.

After a certain residence time in the basin, all lice let go of the fish and sink down in the water basin towards the bottom. Here, the lice pass one or more grids 20 that let lice through and which in addition can separate different size fish in the basin 22 and which prevents the fish from coming down into the bottom zone.

It can be an advantage, but no prerequisite, that the bottom section slopes gently downwards and ends up at the bottom of the basin 22 in a sump for the best possible collection of lice which can then be sucked up. At the end of the basin 22, a diagonal collecting chute 30 for the collection of lice from the fish is shown, and which can be pumped up into a separating tank 40 for destruction. This implies that the delousing takes place in a controlled, gentle and environmentally friendly way, as no pumping of the fish is required. The delousing agent does not require any manual handling and large amounts of delousing agent will be saved, which therefore does no harm to the environment .

If the water bath with delousing agent is not sufficient, or that one prefers an extra mechanical delousing to get an even more effective delousing process, one can imagine that, for example, according to the invention, the inlet channel 5 is equipped with an ejector with spray nozzles which, for example, are driven by water pressure from the ballast pump and the pipeline.

In this way, the module 10 can serve as a delousing device for mechanical delousing with one or more ejectors and a chemical basin 22, or a combination of these.

To document important data with regard to reporting, for example, to the authorities, an apparatus for counting, average weight measurements and lice counting of fish that swims through is shown.

Measurement data and other processes can . therefore be controlled and monitored from a control unit on the upper deck with a PC and control central. All data can be sent from the control room over the internet to a central base ashore or directly to the authorities.

Figure 6 shows how the mobile module 10 can be moved between different cages in a fish farming installation. The arrows show the movement of the module 10 with the help of the equipment described above, from its position between the cages 12, 14 and to a position between the original cage 12 and a new cage, or to a new position between two completely new cages. Alternatively, the module can also be connected to one single cage, as explained, where the module has one combined inlet and outlet.