SHELL PROTECTION DEVICE AROUND A VERTICAL GROWING SUPPORT

Abstract

SHELLFISH PROTECTION DEVICE AROUND A VERTICAL CULTIVATION SUPPORT The present invention relates to a device (100) for protecting shellfish cultivated on a vertical cultivation support, characterized in that it comprises: - a frustoconical body (102) with an overall square cross-section having an upper rim (116) and a lower rim (118), the body being open at both ends to provide a recess (120) for the passage of a cultivation support (200), - locking means for locking the body (102) in position on said support (200). Fig. 1

Description

Title of the invention: DEVICE FOR PROTECTING SHELLFISH AROUND A VERTICAL CULTIVATION SUPPORT

[0001] The present invention relates to a device for protecting shellfish cultivated on a vertical cultivation support, such as a stake. The invention finds particular application in the field of mussel farming using the bouchot method.

[0002] The bouchot method consists of raising bivalve shellfish, such as mussels, on vertical supports such as stakes, of round or square sections, of various species, planted in the ground at a sufficient depth to ensure the necessary support. The spacing between each stake is identical throughout the same row which is called a bouchot. The length of a bouchot varies according to the structural plan specific to each production center. On each stake, a rope, generally made of natural or synthetic coconut fibers, can be wound around its vertical axis, capturing mussel spat of the Mytilus edulis or Gallo-provincialis type, or a boudin, that is to say a net filled with packets of mussels whose diameter corresponds to a large rope. Once in place, the young mussels gradually leave their capture rope or sausage, to colonize all or part of the surface of the pile.Several single-use nets, called drag nets, are successively placed on the piles, the nets creating an additional gripping surface helping the young mussels in their colonization and at the same time offering protection against repeated attacks from the waves. Each pile is, in addition, covered longitudinally with a protective sheath, or net, generally made of plastic. This protective device, similar to a drag net, is knotted on its upper part and open on its lower part.

[0003] According to this farming technique, shellfish are subject to attacks from a good number of marine predators, particularly spider crabs. Spider crabs can be considered an invasive species. They proliferate in the areas where the mussels they feed on are grown, causing increasingly significant losses for mussel farmers. For example, a mussel pile can contain, under normal conditions, an average of 50 kg of mussels. Due to repeated attacks by spider crabs, the harvest may not exceed 5 kg per pile.

[0004] Spider crabs move along the seabed and can easily climb up the cultivation piles.

[0005] Today there is a need to find technical solutions to prevent spider crabs from attacking shellfish crops on vertical supports.

[0006] The present invention aims to solve this problem.

[0007] In particular, the invention aims to propose a device which prevents sea spiders from climbing along vertical supports.

[0008] To this end, the invention relates to a device for protecting shellfish cultivated on a vertical cultivation support, characterized in that it comprises: - a body of truncated cone shape and generally square section having an upper edge and a lower edge, the body being open at its two ends so as to provide a recess for the passage of the support, - locking means intended to lock the body in position on said support.

[0009] The device is characterized in particular by its simplicity of use. It can in fact be installed on a support by threading from the top of the support and sliding, manually or using a rod, along this support to its final position, at the level of the base of the culture support.

[0010] The truncated cone shape of the body effectively prevents sea spiders or other crustaceans from penetrating inside the protective sheath and climbing along the support.

[0011] Advantageously, the body has generally rounded corners which are radially bulged from the upper rim.

[0012] The rounded corners make it easier for the device to slide along the support by contributing to elastic deformation.

[0013] Preferably, each corner of the upper edge has at least one slot with a longitudinal Z or zigzag section.

[0014] The presence of these slots allows the section of the device to vary slightly. This facilitates the sliding of the device along the support to its final position. This also dampens variations in the section of the growing medium.

[0015] According to a preferred embodiment, the locking means are composed of fingers projecting from the upper edge of the body.

[0016] Advantageously, each finger has one or more rows of teeth projecting from the inner face of each finger, each tooth sloping towards the upper edge.

[0017] This type of locking means is particularly effective in holding the device in its position along the growing medium.

[0018] The device may have a variable number of fingers.

[0019] According to one embodiment, the upper rim being of square section, two of its sides, parallel to each other, each comprise two fingers and the other two of its sides each comprise one finger.

[0020] The invention also relates to a set for protecting shellfish cultivated on a vertical support, which is characterized in that it comprises at least one device as described previously.

[0021] Such an assembly may in particular include other protection devices, for example sheath spacing devices such as those described in the French patent application published under number FR3121325 A1.

[0022] The above-mentioned features of the invention, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0023] [Fig-1] is a side view of a device according to a first embodiment of the invention,

[0024] [Fig.2] is an enlarged view of a locking device according to a second mode of operation lization of the invention,

[0025] [Fig.3] is a view of a set of protection for shellfish grown on a vertical support according to one embodiment of the invention.

[0026] In [Fig. 1] is illustrated a device 100 for protecting a culture of shellfish, in particular mussels, against predators, in particular sea spiders.

[0027] The device 100 comprises a body 102, of truncated cone shape.

[0028] The body 102 has a square cross-section. The body thus has four faces including faces 104, 106 and 108 as well as an upper rim 116 and a lower rim 118.

[0029] The body 102 is open at its two ends and therefore crossed by a recess 120.

[0030] The body 102 is preferably made of plastic.

[0031] The upper rim 116 has four corners 109, 110, 112, 114 which are glo rounded and swollen radially outwards.

[0032] The bulge of each corner 109, 110, 112, 114 is closed by a flat surface 122, 124, 126, 128, respectively.

[0033] Each flat surface 122, 124, 126, 128 has a slot 130, 132, 134, 136 arranged in a generally Z-shaped form.

[0034] The device 100 also has locking means allowing it to be locked in position along a vertical cultivation support.

[0035] According to the embodiment illustrated in Figures 1 and 2, the locking means are composed of fingers 138, 140, 142, 144, 146, 148 which project from the upper edge 116 of the body 102. Each finger, such as 148, therefore extends in the extension of a wall, such as the wall 108 and in a direction parallel to the plane of this wall.

[0036] Each finger, such as finger 148, has an inner surface, i.e. the surface facing the recess 120, which is notched and composed of several rows of teeth or notches, such as rows 150 and 152. The teeth project from the inner face inner edge of finger 148, and incline towards the upper edge 116.

[0037] According to the embodiment illustrated in Figures 1 and 2, the upper rim 116 being of square section, two of its parallel sides each comprise two fingers 140, 142, 146, 148, respectively and the other two of its sides each comprise a finger 138, 144, respectively.

[0038] The body 102 of the device 100 here has a height of 30 cm, or generally between 20 and 40 cm.

[0039] The device 100 is installed as follows. The device 100 is threaded from the top 201 of a culture support 200, manually or using a tool such as a rod when the support 200 is underwater.

[0040] In the latter case, it is noted that the intervention of a diver is not necessary, the installation being done via the top 201 of the support 200 by a person located for example on a boat. The device 100 having the function of preventing the crustaceans from rising along the support 200, it is therefore pushed along the support 200 towards the bottom 202 until it reaches its final position, in contact with the ground.

[0041] Once positioned, the fingers 138, 140, 142, 144, 146, 148 prevent the device 100 from rising along the support 200.

[0042] .

Claims

Claims

1. Device (100) for protecting shellfish cultivated on a vertical cultivation support, characterized in that it comprises: - a body (102) of truncated cone shape and of generally square section having an upper rim (116) and a lower rim (118), the body being open at its two ends so as to provide a recess (120) for the passage of a cultivation support (200), - locking means intended to lock the body (102) in position on said support (200).

2. Device (100) according to claim 1, characterized in that the upper rim (116) has generally rounded corners (109, 110, 112, 114) which are radially bulged.

3. Device (100) according to claim 2, characterized in that each corner (109, 110, 112, 114) of the upper edge (116) has at least one slot (130, 132, 134, 136) of longitudinal section in Z or zigzag.

4. Device (100) according to one of the preceding claims, characterized in that the locking means are composed of fingers (138, 140, 142, 144, 146, 148) projecting from the upper edge (116) of the body (102).

5. Device (100) according to the preceding claim, characterized in that each finger (138, 140, 142, 144, 146, 148) has one or more rows (150, 152) of teeth projecting from the inner face of each finger, each tooth (150, 152) sloping towards the upper rim.

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