GB2374788A

GB2374788A - Fish protection device

Info

Publication number: GB2374788A
Application number: GB0110097A
Authority: GB
Inventors: John Francis Paton; Martin Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-25
Filing date: 2001-04-25
Publication date: 2002-10-30
Also published as: GB0110097D0

Abstract

The device (10) comprises a hollow housing (12) having one or more openings (18) through which fish can enter the interior of the housing (12) and are protected from predatory birds. The device may have a solid upper surface (14). The device may be spherical, port spherical, cylindrical, octahedral or rhombic. The device may be portable and a plurality of devices may be interconnected or tessellated.

Description

Improvements in or relating to the protection of live fish This invention relates to a live fish protecting device and to a method of reducing the depletion of a population of fresh water fish by predators.

In recent times, due to the growth in use of commercial fish farms and fishing lakes, an abundant supply of fish coupled with the protected species laws has caused an explosion in the size of the population of predators.

All avian predators are protected under law throughout the United Kingdom, Europe and the United States of America, and extermination cannot be undertaken without a licence issued by the Ministry for Agriculture, fisheries and Food (MAFF). Other, non-fatal methods include netting over an area of the body of fresh water which the fish inhabit, thereby preventing the birds from landing or diving.

The fundamental problem with these two methods of control are that a licence can be difficult to obtain from the MAFF, and netting, apart from being unsightly, not only prevents other water fowl from using the lake, but also makes angling impossible.

The present invention seeks to overcome this problem.

According to a first aspect of the present invention, there is provided a live fish protection device for protecting live fish from predatory birds, the device

comprising a hollow housing having one or more openings through which fish can enter the interior of the housing.

Preferable and/or optional features of the first aspect of the present invention are set out in claims 2 to 10, inclusive.

According to a second aspect of the present invention, there is provided a method of reducing the depletion of a population of fresh water fish by predatory birds, the method comprising the step of placing one or more of the devices as claimed in any one of the preceding claims into a body of fresh water so that fish can enter the interior of the housing through the or each opening to prevent access to them by predatory birds.

Preferable and/or optional features of the second aspect of the present invention are set out in claims 13 to 15, inclusive.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a plan view of one embodiment of a live fish protecting device, in accordance with the first aspect of the present invention; Figure 2 is a side view of the device shown in figure 1;

Figure 3 is a sectional view taken along line A-A in Figure 1; Figure 4 is a plan view of a second embodiment of the live fish protecting device, in accordance with the first aspect of the present invention; Figure 5 is a plan view of a third embodiment of the live fish protecting device, in accordance with the first aspect of the present invention; and Figure 6 is a side view of the device shown in figure 5.

Referring to Figures 1 to 3 of the drawings, there is shown a first embodiment of a live fish protecting device 10 which is typically formed from a metal having corrosion resistant properties or from plastics material, such as GRP, using, for example, blow moulding, vacuum forming, rotational moulding or injection moulding techniques.

The device 10 comprises a housing 12, the major dimension (s) of which is/are typically 0.5 metres to 4 metres. In this embodiment, the housing 12 is partspherical and has top and bottom surfaces 14 and 15 and a side surface 16. The top surface 14 is solid. The side surface 16 of the housing 12 is formed from a plurality of arcuate elongate elements 17, which are spaced apart from each other. The spacing between the elongate elements 17 is such as to create openings 18 therebetween.

The openings 18 have a maximum width of 50 millimetres. However, this width may be altered to take account of the size of the fish and the type of predator typically found in the locality in which the device 10 will be used.

In use, the device 10 is placed into a body of fresh water (not shown), in particular a lake or stretch of river. The device 10 is oriented so that the bottom surface 15 lies on the bed of the body of water. Due to the openings 18 having the maximum width of 50 mm, the fish inhabiting the body of fresh water have ready access to and egress from the hollow interior of the housing 12. However, predators, such as diving Cormorants and otters, are prevented from entering the interior of the housing 12 due to the relative narrowness of the openings 18.

The device 10 may be sized to enable a shoal of fish to be accommodated therein, and since the device 10 has a solid top surface 14, the fish sheltering in the device 10 are hidden from aerial view.

The device 10 is portable and thus may be periodically repositioned.

Also, the device 10 may utilise an anchoring element (not shown) to in use hold it in place, if necessary. A plurality of the devices 10 can be used, and may be interconnected to form a network of any size or shape, simulating a naturally occurring reef structure.

Although this embodiment is described with reference to a part-spherical

device 10, the device could in fact be spherical.

Referring now to Figure 4, a second embodiment of the live fish protecting device 10 is shown therein. In this embodiment, the top surface 14 is apertured with openings 18', which in use provides the fish with a further entrance to and exit from the housing 12. The openings 18', similar to the openings 18, typically have a maximum transverse dimension of 50 millimetres.

Figures 5 and 6 show a third embodiment of the live fish protecting device 10. In this embodiment, the housing 12 is cylindrical and has a solid top 14. As such, the side 16 of the housing 12 is formed from a plurality of rectilinear elongate elements 17'.

Although the elongate elements 17'may be positioned to form the openings 18 having the maximum transverse dimension of 50 mm, in this case the elongate elements 17'are spaced further apart and the device 10 further comprises a subsidiary layer of material 19 in which the openings 18 are formed. The subsidiary material 19 is attached to the housing 12 so as to cover its side 16.

In a modification, the device 10 can take the form of a rhombic dodecahedron or a truncated octahedron. This enables a plurality of the devices 10 to be interconnected in a tessellated arrangement, thus eliminating or substantially eliminating any gaps between devices 10 by which fish might be exposed.

The device 10 is not limited to the shapes described and may be of any suitable shape by which the same or similar effect (s) can be achieved.

By use of the live fish protecting device, it is possible to provide protection for fresh water fish. The device can be easily positioned and repositioned within a fresh water habitat and joined with other devices, without resorting to actively destroying the predators that prey on the fish.

The embodiments described above are given by way of example only and various modifications will be apparent to persons skilled in the art without departing from the scope of the invention.

Claims

Claims 1. A live fish protection device for protecting live fish from predatory birds, the device comprising a hollow housing having one or more openings through which fish can enter the interior of the housing.
2. A live fish protection device as claimed in claim 1, wherein the housing includes a solid or substantially solid in use upper surface.
3. A live fish protection device as claimed in claim 1 or claim 2, wherein the housing includes a plurality of the openings dimensioned to allow the fish, but not the birds, to pass therethrough.
4. A live fish protection device as claimed in claim 3, wherein each opening has a maximum width of 50 mm.
5. A live fish protection device as claimed in claim 3 or claim 4, wherein the openings are located in a side or sides of the housing.
6. A live fish protection device as claimed in any one of the preceding claims, wherein the housing is portable.
7. A live fish protection device as claimed in any one of the preceding claims, wherein the housing is spherical or part spherical.

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8. A live fish protection device as claimed in any one of claims 1 to 6, wherein the housing is cylindrical.
9. A live fish protection device as claimed in any one of claims 1 to 6, wherein the housing is a rhombic dodecahedron.
10. A live fish protection device as claimed in any one of claims 1 to 6, wherein the housing is a truncated octahedron.
11. A live fish protection device substantially as hereinbefore described with reference to Figures 1 to 3, Figure 4, or Figures 5 and 6 of the accompanying drawings.
12. A method of reducing the depletion of a population of fresh water fish by predatory birds, the method comprising the step of placing one or more of the devices as claimed in any one of the preceding claims into a body of fresh water so that fish can enter the interior of the housing through the or each opening to prevent access to them by predatory birds.
13. A method as claimed in claim 12, further comprising the step of periodically repositioning the device (s) within the body of water.
14. A method as claimed in claim 12 or claim 13, wherein a plurality of the devices are interconnected.

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15. A method as claimed in claim 14 when claim 12 is dependent on claim 9 or claim 10, wherein the devices are tessellated.