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: SHELL PROTECTION DEVICE AROUND A VERTICAL GROWING SUPPORT

[0001] The present invention relates to a protective device for shellfish cultivated on a vertical growing support, such as a stake. The invention is particularly applicable to mussel farming using the bouchot method.

[0002] The bouchot method consists of cultivating bivalve shellfish, such as mussels, on vertical supports such as stakes, of round or square cross-section, made of various types of wood, planted in the ground at a sufficient depth to ensure their stability. The spacing between each stake is identical along the entire length of a row, which is called a bouchot. The length of a bouchot varies according to the structural design specific to each production center. A rope, generally made of natural or synthetic coconut fibers, containing mussel spat of the Mytilus edulis or galloprovincialis type, or a boudin (a net filled with bundles of mussels) with a diameter corresponding to a thick rope, can be wound around each stake's vertical axis. Once in place, the young mussels gradually leave their collection rope or sausage, to colonize all or part of the surface of the stake.Several single-use nets, known as catinage nets, are successively placed on the piles. The nets create an additional attachment surface, aiding the young mussels in their colonization and simultaneously offering protection against repeated wave impact. Each pile is also covered lengthwise with a protective sleeve, or net, usually made of plastic. This protective device, similar to a catinage net, is knotted at its top and open at its bottom.

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

[0004] Sea spiders move on the seabed and can easily climb up the cultivation stakes.

[0005] There is now a need to find technical solutions to prevent sea spiders from attacking shellfish crops on vertical supports.

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

[0007] In particular, the invention aims to provide a device that prevents sea spiders from climbing up vertical supports.

[0008] To this end, the invention relates to a device for protecting shellfish cultivated on a vertical culture support, characterized in that it comprises: - a body with a truncated cone shape and an overall square cross-section, having an upper rim and a lower rim, the body being open at both ends 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 ease of use. It can indeed be installed on a support by threading it from the top of the support and sliding it, manually or with the help of a rod, along this support to its final position, at the level of the base of the growing support.

[0010] The truncated cone shape of the body effectively prevents sea spiders or other crustaceans from entering 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 participating in the elastic deformation.

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

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

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

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

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

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

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

[0020] The invention further relates to a shell protection system for shells grown on a vertical support, which is characterized in that it comprises at least one device as described above.

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

[0022] The features of the invention mentioned above, as well as others, will become clearer upon reading the following description of an exemplary embodiment, said description being made in relation to the accompanying 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 embodiment of the invention,

[0025] [Fig.3] is a view of a shell protection assembly cultivated on a vertical support according to an embodiment of the invention.

[0026] Figure 1 illustrates a device 100 for protecting a shellfish culture, in particular mussels, against predators, in particular sea spiders.

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

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

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

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

[0031] The upper rim 116 has four corners 109, 110, 112, 114 which are generally rounded and bulging 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 further has locking means allowing it to be locked in position along a vertical growing support.

[0035] According to the embodiment illustrated in Figures 1 and 2, the locking means consist of fingers 138, 140, 142, 144, 146, 148 that protrude from the upper edge 116 of the body 102. Each finger, such as 148, therefore extends along the line of a wall, such as wall 108, and in a direction parallel to the plane of that wall.

[0036] Each finger, such as finger 148, has an inner surface, that is, the surface facing the recess 120, which is serrated and composed of several rows of teeth or notches, such as rows 150 and 152. The teeth project from the inner face of finger 148 and are inclined 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 one 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 set up as follows. The device 100 is threaded from the top 201 of a growing medium 200, either manually or with the aid of a tool such as a rod when the medium 200 is underwater.

[0040] In this latter case, it should be noted that the intervention of a diver is not necessary, as the support 200 is put in place via the top 201 by a person located, for example, on a boat. The device 100, whose function is to prevent crustaceans from climbing up the support 200, is therefore pushed along the support 200 towards the bottom 202 until it reaches its final position, in contact with the seabed.

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

[0042] .

Claims

Demands

1. Device (100) for protecting shellfish cultivated on a vertical culture support, comprising: - a frustoconical body (102) with an overall square cross-section, of a height between 20 and 40 cm, having an upper rim (116) and a lower rim (118), the body being open at both ends so as to provide a recess (120) for the passage of a culture support (200), the upper rim (116) having generally rounded corners (109, 110, 112, 114) which are radially swollen, - locking means for locking the body (102) in position on said support (200), characterized in that each corner (109, 110, 112, 114) of the upper rim (116) has a bulge closed by a flat surface (122, 124, 126, 128) each having at least one slot (130, 132, 134, 136) with a longitudinal Z or zigzag cross-section.

2. Device (100) according to claim 1, 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).

3. 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) inclined towards the upper edge.

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