NO20220800A1

NO20220800A1 - System and method for disposing of sea lice

Info

Publication number: NO20220800A1
Application number: NO20220800A
Authority: NO
Inventors: Rune Eritzland
Original assignee: Askvik Aqua As
Priority date: 2022-07-14
Filing date: 2022-07-14
Publication date: 2024-01-15
Also published as: NO348796B1; WO2024014960A1

Description

SYSTEM AND METHOD FOR DISPOSING OF SEA LICE

FIELD

The present invention relates to a system and method for disposing of sea lice.

BACKGROUND

Efficient and cost-effective farming of species in the Salmonidae fish family is often marred by the presence of sea lice in the water. Many efforts have been made to reduce and try to eliminate sea lice from commercial fish farms.

One known method is to suck volumes of water and fish onto a vessel where the fish can be cleaned of sea lice using various known techniques and then delivered back to the water to continue growing. The water is then typically cleaned of sea lice by passing the water through a drum filter which catches the sea lice such that they can be disposed of. This method has limitations in that the filters are prone to clogging and overflowing. The filters may become clogged with the lice themselves or with mucus from the lice. Furthermore, lice are sometimes collected in large lice bags which may split or crack. It is important to wash or clean the filters. This can be time consuming and difficult. For example, it may take around seven hours to clean and disinfect each lice filter.

When fish are moved or collected for slaughter, a large quantity of lice are also often collected. Large numbers of lice fall off of the fish and into water filter boxes and sorting systems. Furthermore, others fall or drop off of the fish when handling and penetrating the fish in cages, in which case the lice are often sucked up by the vessel’s fish pump system and therefore are sucked into filters.

The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art.

The object is achieved through features, which are specified in the description below and in the claims that follow.

SUMMARY

According to a first aspect of the invention, there is provided an apparatus for delivering sea lice to a depth in water such that the sea lice cannot survive, the apparatus comprising: an elongate tubular member comprising: a walled portion; an upper portion comprising an inlet; and a lower portion comprising an outlet in fluid communication with the inlet, wherein the inlet is configured to be connected to an inlet hose or pump to receive sea lice, and the elongate tubular member is configured such that: the upper portion can be located above the water surface in use; and the lower portion can be located below the water surface in use, such that the outlet can be provided at a depth in the water in use; and sea lice travelling from the inlet to the outlet cannot pass through the walled portion in use.

The elongate tubular member may have a length connecting the inlet to the outlet of greater than 50m, or between 50m and 400m or between 75m and 200m or between 80m and 150m or around 110m.

The elongate tubular member may be configured such that the outlet can be positioned at a water depth of around 100m in use.

The elongate tubular member may be cylindrical in cross-section.

The walled portion may be configured to not allow water to pass therethrough. The walled portion may comprise a mesh configured to allow water to pass therethrough and configured to not allow sea lice to pass therethrough.

The second portion may comprise a weight configured be located below the water in use.

The inlet may be configured to be connected to an inlet hose or pump to receive water in use.

The apparatus may further comprise a pump fluidly connected to the inlet and configured to deliver sea lice to the inlet.

The pump may be further configured to deliver water to the inlet.

According to a second aspect of the invention, there is provided a cleaning and disposing system for removing sea lice from fish and delivering the sea lice to a depth in water such that the sea lice cannot survive, the system comprising: the apparatus according to the first aspect of the invention; and a cleaning system for cleaning sea lice from fish; wherein the cleaning system is configured to remove sea lice from fish.

According to a third aspect of the invention, there is provided a method of delivering sea lice to a water depth such that the sea lice cannot survive, the method comprising the steps of: providing an apparatus according to the first aspect of the invention; arranging the upper portion above the water surface and the lower portion below the water surface such that the outlet is at a water depth at which sea lice cannot survive; pumping sea lice through the elongate tubular member such that the sea lice are delivered to the water depth at which they cannot surface at the outlet of the elongate tubular member.

The step of pumping sea lice through the elongate tubular member may further comprise pumping water through the elongate tubular member.

The described apparatus, system and method may provide the benefit of not needing to filter or collect the sea lice on the boat. Instead the sea lice can be pumped to a depth at which they cannot swim back to the surface and/or cannot survive.

Additionally, since a filter is not required to separate the sea lice from the water, the requirement that the filter is washed and/or disinfected may be eliminated.

Additionally, there may be no spread of lice in the surface or areas where the fish may be located.

The sea lice may not be able to swim back towards the surface once they are ejected from the outlet.

Additionally, the delivery of sea lice to a deep depth below the location of fish to be farmed may have a positive effect on the fish. In this connection, the sea lice may supply oxygen-rich water to the sludge below the location of the fish, and may possibly provide improvement of the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described with reference to the following drawings, in which:

Figure 1 shows a prior art apparatus for disposing of sea lice; and

Figure 2 shows an apparatus for disposing of sea lice according to an aspect of

the invention.

For clarity reasons, some elements may in some of the figures be without reference numerals. A person skilled in the art will understand that the figures are just principal drawings. The relative proportions of individual elements may also be distorted.

DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1 shows a boat 1, a surface 2 of a volume of water, an inlet line 3, a cleaning station 4, a return line 5, collection line 6 and fish 7. The boat 1 is floating at the surface 2 of the volume of water. The boat 1 is used to temporarily lift fish 7 from the water such that the fish 7 can be cleaned of sea lice and returned to the water or collected. The fish 7 are sucked from the water using the inlet line 3 and brought to a cleaning station 4 on board the boat 1. The cleaning station 4 comprises a means for removing sea lice from the fish 7 and a means for separating the sea lice from the water. It will be understood by a person skilled in the art that there is myriad of ways of removing sea lice from the fish 7.

As examples only, sea lice may be removed from the fish 7 by high-pressure water jets, by laser technology, by physical contact with the skin of the fish 7 etc. The means by which the sea lice are removed is not important. Once a quantity of sea lice has been removed from the fish 7, the fish 7 can be returned to the water with a reduced number of sea lice attached to their bodies, or completely free of sea lice. The fish 7 may be returned to the water via a return line 5. Alternatively, the fish 7 may be collected via the collection line 6 into a suitable receptacle (not shown). The means for separating the sea lice from the water in the presently described example is a drum filter. The sea lice are delivered in water to the drum filter which catches the sea lice such that they can be disposed of.

Figure 2 shows a boat 100 floating at the surface 200 of a volume of water. Similarly to the boat 1 shown in Figure 1, the boat 100 is used to temporarily lift fish 700 from the water such that the fish 700 can be cleaned of sea lice and returned to the water or collected. The fish 700 are sucked from the water using an inlet line 300 and delivered to a cleaning and disposing system 400 for removing sea lice from the fish 700 and delivering the sea lice to a depth in the water such that the sea lice cannot survive, as will be explained in more detail.

The cleaning and disposing system 400 comprises a cleaning system 410 configured to remove sea lice from the fish 700. The cleaning and disposing system 400 further comprises an elongate tubular member 420 comprising a walled portion 421, an upper portion 422 comprising an inlet 423, and a lower portion 424 comprising an outlet 425 in fluid communication with the inlet 423. The cleaning and disposing system 400 further comprises a pump 430 connected to the inlet 423 and configured to pump sea lice to the inlet 423 and down the elongate tubular member 420, as will be explained in more detail.

As can be seen in Figure 2, the elongate tubular member 420 is arranged in use such that the upper portion 422 is located above the water surface 200 and the lower portion is below the water surface 200, such that the outlet 425 is located at a depth d below the water surface 200.

The walled portion 421 of the elongate tubular member 420 is configured to not allow sea lice to pass through the walled portion 421, therefore the sea lice pumped into the elongate tubular member 420 must travel from the inlet 423 to the outlet 425.

The depth d at which the outlet 425 is located in the presently described example is around 100m. The elongate tubular member 420 in the presently described example is around 110m in length. It will be understood that in other examples the elongate tubular member 420 may be another suitable length.

The elongate tubular member 420 in the presently described example is circular in cross-section, therefore the elongate tubular member 420 shown in Figure 2 is a hollow cylinder. In other examples, other cross-sectional profiles may be used, such as but not limited to square or rectangular profiles.

Depending on the depth of the outlet 425 in use, the sea conditions, the materials used for the elongate tubular member 420 and the weight of the elongate tubular member 420, it may be beneficial in some cases to provide a weight (not shown) on the elongate tubular member 420. The weight may in some cases be located at or near the outlet 425.

In use, the boat 100 is provided at a location where the fish 700 within the water must be cleaned of lice. As described above, fish 700 are sucked onto the boat using the inlet line 300. The sea lice are removed from the fish 700 in any known way by, for example, using a high-pressure water jet. The removal of the sea lice from the fish 700 is performed by the cleaning system 410. The cleaned fish 700 are either delivered back into the water through a return line 500 to continue growing or are collected via a collection line 600 into a suitable receptacle (not shown). The removed sea lice are then pumped by the pump 430 to the inlet 423 and down the elongate tubular member 420 to the outlet 425. Once the sea lice exit the outlet 425, they are unable to swim to near the surface again. Sea lice swim in short stages and then sink back, therefore, to swim a long distance to reach near the surface, the sea lice will become exhausted and run out of energy. Furthermore, sea lice become heavier due to the pressure at around 100m water depth, and this ensures that it is too difficult and tiring for the sea lice to swim up to near the water surface. The result is that the sea lice cannot return back to near the surface and attach themselves to a fish 700 again.

When salmon lice are delivered to a deep location, for some time the blood / transport fluid may not be able to circulate properly and the lice may die from a blood clot or too little oxygen. Dead lice at the deep location may become easy prey for deep dwelling species.

In some examples only sea lice may be pumped through the elongate tubular member 420. In other examples, water and sea lice may be pumped through the elongate tubular member 420.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. An apparatus for delivering sea lice to a depth in water such that the sea lice cannot survive, the apparatus comprising:

an elongate tubular member comprising:

a walled portion;

an upper portion comprising an inlet; and

a lower portion comprising an outlet in fluid communication with the inlet,

wherein the inlet is configured to be connected to an inlet hose or pump to receive sea lice, and

the elongate tubular member is configured such that:

the upper portion can be located above the water surface in use; and the lower portion can be located below the water surface in use, such that the outlet can be provided at a depth in the water in use; and sea lice travelling from the inlet to the outlet cannot pass through the walled portion in use.

2. The apparatus according to claim 1, wherein elongate tubular member has a length connecting the inlet to the outlet of greater than 50m, or between 50m and 400m or between 75m and 200m or between 80m and 150m or around 110m.

3. The apparatus according to any preceding claim, wherein the elongate tubular member is configured such that the outlet can be positioned at a water depth of around 100m in use.

4. The apparatus according to any preceding claim, wherein the elongate tubular member is cylindrical in cross-section.

5. The apparatus according to any preceding claim, wherein the walled portion is configured to not allow water to pass therethrough.

6. The apparatus according to any of claims 1 to 4, wherein the walled portion comprises a mesh configured to allow water to pass therethrough and configured to not allow sea lice to pass therethrough.

7. The apparatus according to any preceding claim, wherein second portion comprises a weight configured be located below the water in use.

8. The apparatus according to any preceding claim, wherein the inlet is configured to be connected to an inlet hose or pump to receive water in use.

9. The apparatus according to any preceding claim, further comprising a pump fluidly connected to the inlet and configured to deliver sea lice to the inlet.

10. The apparatus according to claim 9, wherein the pump is further configured to deliver water to the inlet.

11. A cleaning and disposing system for removing sea lice from fish and delivering the sea lice to a depth in water such that the sea lice cannot survive, the system comprising:

the apparatus of claim 9 or 10 for delivering sea lice to a water depth; and a cleaning system for cleaning sea lice from fish;

wherein the cleaning system is configured to remove sea lice from fish.

12. A method of delivering sea lice to a water depth such that the sea lice cannot survive, the method comprising the steps of:

providing the apparatus according to any of claims 1 to 10; arranging the upper portion above the water surface and the lower portion below the water surface such that the outlet is at a water depth at which sea lice cannot survive;

pumping sea lice through the elongate tubular member such that the sea lice are delivered to the water depth at which they cannot surface at the outlet of the elongate tubular member.

13. The method according to claim 12, wherein the step of pumping sea lice through the elongate tubular member further comprises pumping water through the elongate tubular member.