WO2013141711A2

WO2013141711A2 - Fish fence, and corresponding system.

Info

Publication number: WO2013141711A2
Application number: PCT/NO2013/000009
Authority: WO
Inventors: Jens Christian HOLTS
Original assignee: Holts Jens Christian
Priority date: 2012-03-23
Filing date: 2013-03-22
Publication date: 2013-09-26
Also published as: WO2013141711A3

Abstract

A fish fence (10) is described to lead, channel or restrict live fish that swim in the water, comprising at least one fence in the form of several fence posts (14) placed after each other in the water, where said fence posts (14) are suspended from a suspension (16) that stretches across the water, and where the fence posts (14) extend down into the water. The invention also relates to a system of fish fences (10).

Description

Fish fence, and corresponding system.

The present invention relates to a fish fence to guide or restrict live fish that swim in water, comprising at least one fence in the form of several fence posts placed after each other in the water. The invention also relates to a system of fish fences. Fish fences are known from before to lead or shut off fish in rivers and the like. The known solutions have

previously comprised of posts that have been inserted down into the bottom, and where the gaps between the posts have been filled with branches, nets or the like. Other

solutions have been to cast foundations for fence posts and thereafter set up a fence, make channels, use sand bags, etc., all with the aim of setting up a bordered path or way in which the fish can move, or completely shut the fish off. It is also known to set up a grid or filter that extends from the bottom to separate out impurities in the water. Lately, it is also known to use acoustic fish fences to border off an area, often in connection with a power station. Common to the known solutions is roughly that they have been relatively bothersome and complicated to set up. Many of the known solutions will also function as a collector of rubbish and other items that come floating in the water and where these impurities must be removed manually.

One object of the present invention is to provide a fish fence and associated system which can easily be set up and which is simple to adjust to the bottom conditions as required, which is simple to modify to adjust to the surroundings in which the fish fence shall be used, and which does not reguire much interference with the

surrounding terrain. One object is also that the invention shall be reversible, i.e. simple to remove.

A further object of the invention is to provide a system for counting, analysing and monitoring, preferably in real time, of fish in a water course or the like. It shall also be possible to use the invention in calm waters and in seas and lakes.

The invention broadly relates to a stretch of fence that hangs down into still or flowing water with the aim of stopping, distracting, dividing or channelling live fish in relation to natural apportionment or behaviour.

Both the fish fence and the system according to the invention can be used standing freely in a river or dam, or be used together with existing solutions, such as salmon stairs.

From patent literature, reference is made to JP 2006257828 A, US 2709984 A and US 2778140 A. None of the above mentioned documents, either alone or in combination, appear to document solutions for providing a possibility for manually and/or automatically setting up a fish fence to be used, or to provide movements in the suspended fence posts, for example, in still waters.

The above mentioned object are obtained with a fish fence to guide or restrict live fish that swim in water, comprising at least one fence in the form of fence posts placed after each other in the water, where said fence posts are hanging from a suspension that runs across the water and the fence posts extend down into the water.

In one embodiment the suspension can comprise an endless chain that runs around respective guiding wheels arranged on each side of the water, where the suspension can comprise a motor for the operation of the endless chain.

The fence posts can be supplied manually or automatically to the suspension from one or more adjoining storages, during the setting out of the present fish fence.

A vibrator can be used to make the suspended fence posts vibrate .

One advantage of the suspension is that it can be possible to be hoisted and lowered, whereby the fence posts are arranged to be hoisted out of the water. The fence posts can be formed as wires or rods that hang down into the water and with a length that is adjusted to the bottom conditions in the water or with a length adapted to the behaviour of the fish in the water.

Furthermore, the fence posts can be equipped with shapes or equipment that promote self-movements in the water and that are arranged to scare the fish away from the fence. The fence posts can further be equipped with weights.

In an alternative embodiment the fence posts can be formed as light rods. Furthermore, the fence posts or the shapes can be arranged to be lit up from above.

The above mentioned objects are also obtained with a system to guide, channel and analyse live fish or other organisms that swim in water, comprising at least one fish fence with several fence posts placed after each other in the water, in which several fish fences comprises fence posts that are hanging from a suspension, where the suspension stretches across the water and the fence posts extend down into the water, are placed in rows, in the main, in parallel to each other and between demarcations in the water. Furthermore, the system comprises at least one channel for swimming fish that is provided through or adjoining said fish fences and an analysis apparatus that is placed in the channel system for analysis of passing fish.

The channel can be provided transversely between the rows of fish fences and one of said demarcations.

The analysis apparatus, or equipment to which the analysis apparatus is connected, can be arranged to count and/or analyse and calculate the biomass of fish. The analysis apparatus, or equipment to which the analysis apparatus is connected, can also comprise communication equipment for transmission of data in real time to a remote lying location . In an alternative embodiment a first set of rows of fish fences can be placed oblique between demarcations in the water and a second set of rows of fish fences can be placed oblique the opposite way between the demarcations in the water, where the channel is provided, in the main, centrally.

The invention shall now be described in more detail with the help of the enclosed figures, in which: Figure 1 shows a principle diagram of a fish fence according to the invention.

Figure 2 shows several fish fences according to the invention .

Figures 3 and 4 show a principle diagram of a system with several fish fences according to the invention.

Figure 5 shows the putting out of a fish fence according to the invention in a dam.

Figure 6 shows principle diagrams of fence posts and shapes to the fence posts according to the invention.

The present invention is initially intended for use in rivers and dams, for example, a dam in connection to a power station and also in the sea. In the example

embodiment shown in figure 1 a fish fence 10 according to the invention is put up in a river 12, where the river has demarcations in the form of the respective river banks 12a, 12b. The demarcations can, of course, also be made up from not just the river banks, for example, channels, ducts or other fences, etc.

As can be seen in the figures the fish fence 10 is formed with several fence posts 14 that are fastened to a

suspension 16 and where the fence posts 14 hang down into the water. The suspension 16 can, in one simple embody- ment, be made up of a rope or a wire that stretches between the river banks 12a, 12b, or as shown in figure 1 comprise an endless chain that runs between two guiding wheels 18a, 18b on each side of the river. The endless chain can be driven by a motor 20. Similarly, a storage 24 with fence posts can be placed on one or both river banks so that during the setting out of the fence 10 the fence posts 14 are hooked onto the suspension 16, i.e. the endless chain, from the storage 24. The suspension 16 can be fastened to foundations 22 or to natural points on the river banks and can be made to be hoisted and lowered (as indicated by the arrows in figure 1) with the help of, for example, a tackle system (not shown) . If there is a large distance between the river banks, so that there will be a large free stretch of the suspension, it can be equipped with an additional

suspension (not shown) that is placed somewhat higher up, for example, corresponding to a suspension bridge, and which will then provide additional support to the

suspension 16.

Alternatively, the fence posts could also be suspended from an existing construction that stretches across the water or the sea, for example, a bridge or similar

construction. Then the suspension can be made up by the bridge or the construction, or the suspension can be fastened to said bridge or construction. The fence posts 14 are suspended, as mentioned, securely in the suspension 16 and extend freely down into the water. The posts have a function of achieving the wanted behaviour change in the fish and can be constructed so that they, in one way or another, create a fright reaction in the fish that approach the fence, so that they react by swimming away from the fence, or along the fence.

Optionally, a channel can be provided that can guide the fish past the fish fence as described in connection with figures 3 and .

The posts 14 that hang down can be made from different materials, such as rope, wire, light rods and the like, and comprise different geometric shapes that promote self- movement of the posts in moving water, for example, as shown in figure 6. The posts can also be weighted in relation to currents to cover the depth that is necessary to achieve a changed behaviour in the fish, or be

constructed with a length that makes it possible to follow the bottom conditions in the water they are placed in. The latter requires a mapping of the bottom conditions.

The fence posts 14 can also be constructed in such a way that floating objects will be attached to the structure to the smallest extent. In still water and when the self- movement of the structure is too small to achieve the wanted change in behaviour, the fence posts can be made to vibrate with the help of one or more vibrators 26, for example, fastened at the ends of the suspension 16 at one or both river banks, as shown in figure 1. Alternatively, the vibrator or vibrators can be fastened in other ways, or to other constructions, but in such a way that the vibrations are transferred to the fence posts. The fence posts 14 can be formed as stiff laths or rods, or as mentioned from rope or wire, for example, as shown in figure 6a. Figure 6b shows the post 14 equipped with a weight 40. Figure 6c shows the post formed as a light rod equipped with a light 42, for example, in the form of LED lights. It is known that light influences the behaviour of fish in the water. Figures 6d and 6e show other shapes 44,46 with which the fence posts can be equipped, or formed as. The shapes shown in figure 6 can make up the whole of, or parts of, the fence posts, and the different forms can also be combined. Furthermore, the shapes or the equipment can have other geometric forms than those shown. They can, for example, be equipped with reflectors so that light that hits the fence posts is reflected and affects the fish. Similarly, the shapes, or the fence posts for that matter, can be equipped with a swivel to create a rotation in the water.

Figure 2 shows several fish fences 10 according to the invention installed in a river 12, where the fences are placed in parallel rows and oblique in the river. To let through bits and pieces that can get stuck to the fish fence, or possibly also to get a controlled through-flow of fish, the uppermost fence (as shown in the figure) can be hoisted for through-flow, while the other fences are down, and thereafter the uppermost fence is lowered again. The fence in the middle can thereafter repeat the same operation of hoisting and lowering, while the other two fences are held down and then finally the corresponding operation for the bottom fence. The operation can be carried out manually or automatically. The fences can also individually be pulled sideways for channelling the fish through . Figure 3 shows a system according to the invention

comprising several fish fences 10 placed as shown in figure 2. In the system that is shown, the objective, in addition to guiding the fish, is also that it shall be counted and analysed. For this objective, a channel 30 is provided between a demarcation in the water, for example, the river bank 12a and/or 12b, so that fish that are swimming up or down the river (indicated by the arrows) will swim along the fish fences and into the channel 30. Longitudinally in the channel a closure 34 will naturally be provided against the spaces between the fish fences. The channel can, if required, be held open or be closed with the help of the fish fences, or other corresponding closure . In the channel 30, or the channels, preferably at the end of the channel seen in the direction the fish shall swim, an analysis apparatus 32 is arranged for counting and analysing of the fish. The analysis apparatus can be an analysis apparatus of a known type, for example, a camera or other device that is arranged to take pictures, video or film of the fish that pass and to count the number of fish that pass. Therefore, such an analysis apparatus is not described in more detail as it is expected that it will be known to a person skilled in the art.

Furthermore, the analysis apparatus, or the equipment to which the analysis apparatus is connected, can be arranged to calculate the biomass of the fish, i.e. the size and weight. In, for example, a trout or salmon river such information will be very useful with regard to stock overviews and travel of the fish, and also the management of the stock. The information can, among other things, also be used for the division of fish quotas in a river.

Furthermore, the analysis apparatus, or the equipment the analysis apparatus is connected to, can comprise

communication equipment for transmission of data in real time so that a continuous monitoring is achieved.

Alternatively, data can be stored on site.

Figure 4 shows a further embodiment of the system

according to the invention. A first set of rows of fish fences 10 are, in the main, placed oblique as shown in figure 3 and a second set of rows of fish fences is placed oblique the other way so that crossing rows are set up. The channel 30 with the analysis apparatus 32 is placed here, in the main, centrally and running along the fish fences. The arrows indicate the direction the fish swim. The number of fence posts 14 in such an assembly must, for every fence 20, be adjusted for the setting up of the channel 30. The fish fences with suspension can otherwise be the same as described previously. The analysis apparatus that is used can be able to

register the number, damage, lice, disease, etc. on passing fish. Furthermore, the analysis apparatus can comprise a large amount of measuring equipment for the measurement of, for example, temperature, turbidity,

(transparency), water level, etc. The analysis apparatus in combination with the fish fence according to the invention can, in this way, provide a complete monitoring system for the collection of data and for management. Figure 5 shows another application area for the fish fence 10 according to the invention. Here, one or more fish fences 10 are placed in a dam installation, for example, for power production, where the fish fences are formed and placed as, for example, shown in figure 1 or figure 2. In the embodiment shown, a fish fence 10 is placed oblique between a forward weir 50 and the dam/river bank 54 so that an area in front of the water inlet 52 to the turbines is closed for fish, which would otherwise come into the turbines, which is unwanted. The fish move normally near the surface of the water and the length of the fence posts 14 that extends down into the water can be adjusted to the type of fish that is in the water way. Alternatively, the fence posts can extend down to the bottom, or as far down as required.

If the water inlet to the turbines is at the forward weir 50, the fish fences 10 can alternatively be arranged somewhat corresponding to that shown in figure 4, though without the channel, so that the fish is led to one or both sides of the exposed fish fences 10.

Thereafter, the fish can be led further into channels, ^" pipes, salmon stairs or the like in the weir 50, for thereafter to swim on freely. Alternatively, a vessel (not shown) can be placed below the dam for the collection of fish and smolt, whereupon fish and smolt can be

transported to a safe release location, for example, outside the area where predators can usually be found. A such solution will also be able to provide a systematic tool to contribute to an increased fish stock in a waterway .

Claims

C L A I M S

1. Fish fence (10) to guide or restrict live fish that swim in water, comprising at least a fence in the form of several fence posts (14) placed after each other in the water, c h a r a c e r i s e d i n that said fence posts (14) are suspended in a suspension (16) that extends across the water, and that the fence posts (14) extend down into the water.

2. Fish fence according to claim 1,

c h a r a c t e r i s e d i n that the suspension (16) comprises an endless chain that runs around respective guiding wheels (18a, 18b) mounted on each side of the water.

3. Fish fence according to claim 2,

c h a r a c t e r i s e d i n that the suspension (16) comprises a motor (20) for operation of the endless chain.

4. Fish fence according to claim 1,

c h a r a c t e r i s e d i n that the fence posts (14) are adapted to be added manually or automatically to the suspension (16) from one or more adjoining storages (24).

5. Fish fence according to claim 1,

c h a r a c t e r i s e d by comprising a vibrator (26) to cause the suspended fence posts (14) to vibrate.

6. Fish fence according to claim 1,

c h a r a c t e r i s e d i n that the suspension (16) is hoistable and lowerable, whereby the fence posts (14) are arranged to be hoisted out of the water.

7. Fish fence according to claim 1,

c h a r a c t e r i s e d i n that the fence posts (14) are formed as wires or rods that hang down into the water, and with a length that is adjusted to the bottom

conditions in the water or with a length adjusted to the behaviour of the fish in the water.

8. Fish fence according to claim 7,

c h a r a c t e r i s e d i n that the fence posts (14) are equipped with shapes or equipment (44,46) that promote self-movement in the water and that arranged to scare the fish away from the fence (10) .

9. Fish fence according to claim 7,

c h a r a c t e r i s e d i n that the fence posts (14) are formed as light rods (42) .

10. Fish fence according to claim 7,

c h a r a c t e r i s e d i n that the fence posts (14) or the shapes are arranged to be lit up from above.

11. Fish fence according to claim 6,

c h a r a c t e r i s e d i n that the fence posts (14) are equipped with weights (40) .

12. System to lead, channel and analyse live fish and other organisms that swim in water, comprising at least one fish fence (20) with several fence posts (14) placed after each other in the water, c h a r a c t e r i s e d i n

that several fish fences (10) comprising fence posts (14) that are suspended from a suspension (16), where the suspension (16) stretches across the water and the fence posts (14) extend down into the water, are placed in rows, in the main, in parallel to each other and between

demarcations in the water,

that at least one channel (30) for swimming fish is provided through or adjoining said fish fences (10), and that an analysis apparatus (30) to analyse the passing fish is placed in the channel (30) .

13. System according to claim 10,

c h a r a c t e r i s e d i n that said channel (30) is provided transversely between the rows of fish fences (10) and one of said demarcations.

14. System according to claim 10,

c h a r a c t e r i s e d i n that the analysis

apparatus (32), or the equipment to which the analysis apparatus is connected, is arranged to count and/or analyse and calculate the biomass of the fish.

15. System according to claim 10,

c h a r a c t e r i s e d i n that the analysis

apparatus (32), or the equipment that the analysis apparatus is connected to, comprises communication

equipment for transmission of data in real time to a remote-lying location.

16. System according to claim 10,

c h a r a c t e r i s e d i n that a first set of rows with fish fences (10) is placed oblique between the demarcations in the water and that a second set of rows with fish fences (10) is placed oblique in the opposite direction between the demarcations in the water, where the channel (30) is provided, in the main, centrally.