WO2020239578A1

WO2020239578A1 - Artificial aquatic habitat module

Info

Publication number: WO2020239578A1
Application number: PCT/EP2020/064073
Authority: WO
Inventors: Fabrice JAVEL; Candice PUISSANT
Original assignee: Suez Groupe
Priority date: 2019-05-24
Filing date: 2020-05-20
Publication date: 2020-12-03
Also published as: FR3096230B1; FR3096230A1

Abstract

An artificial aquatic habitat module (1) comprising a body (11), a plurality of flexible strands (12) fixed on said body (11) and fixing means intended to fix the module (1) on a submerged support, the body (11) being formed by a loop-shaped element that forms at least one of said means for fixing on the support, the strands (12) extending by radial projection at least on a portion of the periphery of said loop-shaped body (11).

Description

Title of the invention: Artificial aquatic habitat module

[0001] The present invention relates to the field of artificial aquatic habitats and more particularly to a habitat structure allowing the restoration of aquatic biodiversity, and more particularly marine biodiversity, in particular an artificial habitat for open-water fish.

Artificial habitat devices are known intended for ecological restoration in the marine environment, in particular intended to be installed on works / infrastructures such as dikes, docks, pipes which have modified the natural relief and therefore the natural fish habitat.

[0003] In fact, certain aquatic animal species take advantage of natural shelters such as underwater reliefs, algae and seagrass to escape their predators. These natural habitats allow these species to feed and protect the earliest stages of life (juveniles) against predators, which allows them to develop and proliferate.

[0004] However, these natural habitats are likely to be disturbed or even destroyed by the implementation of maritime infrastructures such as ports, dikes which modify the natural relief and thereby disturb the natural shelter areas.

[0005] In order to overcome these drawbacks, artificial systems have therefore been proposed so as to recreate suitable habitats for developing and promoting the density of aquatic species in areas where the ecological functions had been altered or destroyed.

[0006] Document FR-A-3030188 describes an artificial aquatic habitat comprising a base formed of at least one base element comprising an assembly portion, the base comprising a hollow shell and a plurality of beam blocks. The beam block comprises a foot from which extend a plurality of rods, flexible enough to accompany the movement of the water while being sufficiently rigid to be able to repel predators and also guarantee the prohibition of access for objects of too big volume. This type of artificial habitat was designed to be fixed to the bottom of bodies of water or to fixed structures such as than docks, pipes, riprap or under floating pontoons in order to recreate a lost habitat, rather in coastal and non-pelagic areas.

[0007] Document US-A-20080233051 proposes a fish habitat consisting of floating strands such as polyethylene and fixed on a body which can be weighed down to rest on the bottom of the water or suspended floating in the water between surface and background. The ends of the strands thus tend to rise towards the surface like grass.

Likewise, in the document US-A-20180235192 is described an artificial aquatic habitat intended for lentic aquatic ecosystems and more particularly those which are artificial such as water reservoirs in which plants may have difficulty establishing themselves. . This artificial habitat consists of flexible and floating corrugated polyethylene tubes linked together and fixed to a floating central body, these tubes radiating around the central body so as to extend in a horizontal plane relative to the bottom of the extent of water while the free ends of these flexible tubes tend to rise to the surface of the water like plants. Such a habitat can be suspended at a specific depth from the bottom, the central floating body being connected to weights resting on the bottom.

An artificial aquatic habitat of this type therefore makes it possible to reproduce habitats at different depths in relation to the bottom but only concerns lentic ecosystems which are calm bodies of water with slow renewal such as lakes, ponds, ponds or at sea but in shallow areas. Such habitats cannot be used in the open sea, because of the depth in relation to the bottom for their anchoring and the hydrodynamic stresses to which such a device would be subjected, which could in particular lead to risks of rupture between the floating habitat and the weights of anchor resting at the bottom.

[0010] Furthermore, it is known that pelagic fish such as amberjacks, triggerfish or dolphinfish, for example, tend to congregate around floating objects such as rafts, wooden logs and others. fixed structures. Research has shown that these fish form aggregates around various such structures where they can be caught with nets. [001 1] Therefore, submerged artificial objects have been proposed (commonly called Fish concentrator device: DCP) so that the fish can be concentrated in sufficient quantity near these underwater structures in preselected areas in order to be able to be captured with various conventional gear

Thus, a system has been proposed which is described in US Pat. No. 4,471,552 which relates to the use of simple and complex structures submerged at the surface and at mid-height to attract and aggregate fish. Assessments of artificial floating objects revealed that more pelagic fish were attracted to three-dimensional structures than to flat horizontal or vertical surfaces. In this document is proposed a system for the concentration of fish, intended to be placed in a body of water in order to recruit a large number of fish in a specific place or area for fishing. Thus, this device can have different configurations depending on the depth of the water, the species of fish desired, the state of the ocean floor, the speed of the currents, the conditions of the waves and the wind as well as other local meteorological and oceanographic environmental conditions.

[0013] Thus, a surface buoy provides a flotation support for a two-dimensional, planar fish attracting device deployed near the surface of the water to resemble a floating raft-type object. This attraction device consists of a frame to which is attached a mesh net.

[0014] The surface buoy is connected by a chain to additional buoys located in the middle of the water column. The buoys below the surface are then connected to an attachment line that extends down to an anchor assembly on the ocean floor. Other devices attracting fish are built in the form of three-dimensional structures, at the attachment line at different water depths, which makes it possible to attract other species of fish. Another device attracting fish consists of an elongated band attached to the attachment line. The tape is generally thin and light, allowing it to ripple in water in response to the slightest movement of current or water. This streamer provides a fixed visual stimulus for the fish, attracting them around this position. However, such a device is a system of aggregation of fish for halieutic purposes but not in no way constitutes an artificial habitat aimed at restoring marine biodiversity, in particular promoting their development and proliferation.

Therefore, none of the devices described above aims to allow the restoration of marine biodiversity, in particular by promoting the survival and development of juvenile stages of pelagic species, by providing an artificial habitat that can be used in the open sea. , making it possible in particular to withstand strong hydrodynamic stresses such as the currents and the swell which are present there.

To this end, the invention aims to provide a modular artificial aquatic habitat and more particularly an artificial aquatic habitat module, fixable on existing installations in the open sea such as buoys or other floating structures, in a simple and efficient manner, while allowing the artificial habitats thus formed to withstand strong hydrodynamic stresses.

[0017] Thus, the main object of the invention is an artificial aquatic habitat module comprising a body, a plurality of flexible strands fixed to said body and fixing means intended to fix the module on an immersed support, characterized in that that the body consists of an element in the form of a loop which constitutes at least one of said means for fixing to the support, the strands projecting radially at least over a part of the periphery of said body in the form of a loop.

[0018] Thus, advantageously, the module according to the invention is submerged and can be fixed directly by its body in the form of a loop on a support, preferably an axial support such as a mooring chain for a buoy. beacon, a post, a stake, a mast such that the strands distributed in radial projection on its periphery can thus float in the water, forming layers of strands at least in part around said loop and the support on which the module is fixed.

[0019] The module being fixed to a submerged support such as a mooring chain for a beacon buoy, it is thus associated with a support which is configured to withstand hydrodynamic stresses.

[0020] According to a preferred embodiment, the body in the form of a loop consists of an open loop, preferably an open (split) ring, on which are fixed flexible strands which project radially from the face. external of said ring all along its periphery thus forming a sheet of flexible strands, deployable as a corolla around the body of said module.

[0021] The body has an opening sized to allow engagement of the axial support within the body which thus surrounds the axial support.

[0022] According to a second embodiment, the loop-shaped body consists of a closed loop and comprises a portion of the hinged or removable loop allowing the opening and closing of the loop-shaped body. The opening of the body in the form of a loop is therefore dimensioned to allow the body to be engaged on an axial support, the body thus surrounding said support. A loop-shaped body can thus be hung directly on a link in the chain, for example, or a fixing eyelet provided at the periphery of a submerged support such as a wind turbine base. The closed-loop-shaped body can thus function as a carabiner, which can be hooked onto a link in the chain of a beacon buoy.

[0023] By open loop is therefore meant a non-continuous loop, for example split, and by closed loop a continuous loop, which can be open.

[0024] Preferably, the fixing means further comprise a means for retaining the body in the form of a loop on the support. The retaining means may preferably consist of a rod extending across the loop and removably attached thereto.

Thus, when the support is a mooring chain, the module is fixed by the loop, open (split) or closed, which surrounds said chain and by the retaining rod which extends across the loop and at the through a link in the chain.

The retaining means can be constituted by the closing / opening part of the closed loop hooked like a carabiner on the support.

[0027] Preferably, the body in the form of a loop is made of a rigid polymer material, preferably a bio-based polymer. Bio-based plastics have the advantage of not releasing substances, or polluting particles, harmful into the environment, these polymers can be made in particular from many different resources such as corn, cassava, potato, etc. wood, cotton, algae, etc. Preferably, such a bio-based polymer also has good abrasion resistance, such as a polyamide based on vegetable oil, such as castor oil.

As already mentioned, the support such as the chain is engaged in the loop by the opening of the latter and the retaining rod previously removed from the loop is reattached to said loop, through a link in the chain , thus retaining the module on the chain. The loop-shaped body is thus fixed on the axial support so that said body extends in a plane substantially perpendicular to the axial support and that the flexible strands, fixed in radial projection on the external face of the body, float and s' extend mainly around the axial support in a corolla, forming layers of floating strands.

[0029] Advantageously, the flexible strands consist of flexible polymer fibers, preferably bio-based polymers, such as a polyamide based on castor oil. The flexible strands have a character of buoyancy allowing them to float around the body of the module and therefore around the support in the form of sheets unfolding in a corolla around the axial support.

[0030] The biobased polymer materials used thus make it possible to prevent the release of harmful and polluting substances into the environment.

These sheets of floating fibers constitute a network of micro-habitats for many organisms such as crustaceans, worms but also juvenile fish.

[0032] The habitat module being fixable on an axial support such as a beacon buoy mooring line, it allows to create artificial habitats in the open sea which makes it possible to effectively and sustainably increase survival and improve the conditions for the development and growth of pelagic species with a view to ecological restoration.

[0033] Advantageously, it is possible to install several artificial habitat modules according to the invention along the same axial support, with modules of different shapes and dimensions. Thus, the invention also relates to an artificial aquatic habitat consisting of at least one module according to the invention and a support on which the module is fixed by its body in the form of a loop.

[0035] According to an advantageous embodiment, a habitat according to the invention consists of at least one module and of an axial support such as a beacon buoy mooring chain, characterized in that each module is fixed on the chain by its body in the form of a loop which surrounds said chain, a retaining rod being engaged across the loop and a link of the chain.

[0036] Advantageously, it is thus possible to create an aquatic habitat having a specific shape and dimensions by positioning adjacent two, three or more modules whose fibers have different, specific lengths along a line of mooring or other open water structure.

[0037] In order to limit the abrasion linked to the friction of the body of the modules on the chain where they are fixed, said chain is covered with a protection such as a spiral band or plastic casing.

Such an aquatic habitat can advantageously be used in a maritime environment, in particular at sea, but it can also be used in fresh water in lakes, ponds.

The invention will now be described in more detail with reference to the accompanying drawings which represent:

[0040] [Fig. 1] a top elevational view of an aquatic habitat module according to one embodiment of the invention;

[0041] [Fig. 2] a side elevational view of the module of Figure 1;

[0042] [Fig. 3] a perspective view from above of a module according to Figure 1 mounted on an axial support;

[0043] [Fig. 4] a side perspective view of an artificial habitat consisting of several modules according to the invention attached to a beacon buoy; [0044] [Fig. 5] an enlarged perspective view of part of a habitat of Figure 4; and

[0045] [Fig. 6] a perspective view of another embodiment of a module body according to the invention.

As can be seen in Figure 5, a module 1 of artificial aquatic habitat according to the invention is intended for use with a buoy at sea or other open water structure such as piles, floating wind turbine or posed. Such a buoy generally consists of an emerged floating part 2 and a submerged anchoring part (not shown), the two being connected by a connecting element such as a chain 3.

This chain 3 between the anchoring part and the floating part 2 thus forms an axial support, which extends substantially vertically below the surface of the water.

The module 1 according to the invention comprises a body 1 1 and a plurality of flexible strands 12 extending from the body 1 1. Preferably, the body 1 1 consists of a loop-shaped element constituting one of the means for fixing the module on the chain 3. The strands 12 consist of flexible fibers arranged in radial projection on at least part of the periphery. outer body of said loop-shaped body 1 1.

Preferably, the body in the form of a loop consists of a ring 1 1 which has an opening 4, for example a split ring, opening through which the chain 3 can be passed so that the loop of binding 1 1 is thus arranged around the chain 3 as can be seen in Figure 3.

According to the embodiment shown in Figure 1, the ring 1 1 consists of a slotted tubular portion having an opening 4.

The module 1 further comprises strands 12 fixed to the body 1 1 and extending radially from the outer face 1 1 a of the body 1 1. Thus, the strands 12 extend, forming a sheet of strands extending in a corolla around the body 1 1 (see Figure 1). The strands 12 are for example fixed to the body by clips, or a jumper passage in the body or any other suitable fixing means. These strands 12 preferably consist of fibers of bio-based polymer. Thus, once the module 1 is in the water, the fibers 12 can float and unfold in a corolla at the periphery of the loop-shaped element 11, thus forming a sheet of floating fibers, undulating according to the rhythm of the currents. and surrounding the chain 3 on which the module 1 is fixed.

These fibers 12 are preferably fixed to the fastening element in the form of bundles of fibers, these bundles being distributed around the fastening element in the form of a loop 1 1 so that the fiber bundles form a web surrounding said loop-shaped element 1 1.

A module 1 is fixable in position on the chain 3 using fixing means comprising the body in the form of a loop 1 1 and which further comprise a retaining means 5 of the body 1 1 in position along the chain 3. This retaining means is, for example, constituted by a retaining rod or crosspiece 6 extending across the loop 1 1 through two orifices made on the body 1 1. The crosspiece 6 can be fixed using reversible fastening means.

Thus, this cross member 6 may have threaded ends which, when the cross member 6 extends across the loop 1 1, extend projecting from said loop 1 1 on either side of the nuts 7 engaging on said ends to fix and hold the crosspiece 6 in place.

When fixing a module 1 according to the invention, on a chain 3 of a beacon buoy, a nut 7 is unscrewed to remove the crosspiece 6 and the body in the form of a loop 1 is set up 1 around chain 3 (the latter passing through opening 4 of loop 1 1) then the cross member 6 is put back in place so that it engages through a link M of the chain 3 before protruding again from the body 1 1 with its threaded end on which the nut 7 is screwed.

The module 1 is thus positioned around the chain 3 and held on the chain 3 in position in a manner that is simple and easy to implement. Once, the loop-shaped element 1 1 fixed on the chain 3, it extends in a plane substantially perpendicular to the main axis of the chain 3 so that the flexible strands 12, fixed projecting radial on the outer face of the body 1 1, float and extend around the axial support 3 corolla, forming layers of floating fibers. An element in loop shape has appropriate dimensions depending on the support to which it is attached.

As can be seen in Figure 5, we can set up several modules 1 according to the invention to create an artificial habitat of more complex dimensions.

As can be seen in Figure 5, the dimensions of the flexible fibers 12 may be different from one module to another so as to create artificial habitats of different shapes.

According to the mode shown in Figure 6, the body in the form of a loop may have the form of a ring 1 10 can be opened to allow its fixing by clamping on an axial support such as a stake.

Once, the loop-shaped element 1 10 clamped on the axial support, the latter extends in a plane substantially perpendicular to the axial upright on which it is fixed so that the flexible strands (not shown ) fixed in radial projection on the outer face of the loop 1 10, float and extend around the axial support corolla, forming layers of floating fibers.

Claims

[Claim 1] Module (1) of artificial aquatic habitat comprising a body (1 1, 1 10), a plurality of flexible strands (12) fixed to said body (1 1, 1 10) and fixing means intended for fixing the module (1) on a submerged support, characterized in that the body (1 1, 1 10) consists of a loop-shaped element which constitutes at least one of said fixing means on the support, the strands ( 12) extending radially projecting at least over a part of the periphery of said body in the form of a loop (1 1, 1 10).

[Claim 2] Module (1) according to claim 1, characterized in that the loop-shaped body (1 1) consists of an open loop.

[Claim 3] Module (1) according to claim 2, characterized in that the body in the form of a loop consists of an open ring (1 1), to which are fixed flexible strands (12) which extend in radial projection from the outer face (1 1 a) of said ring (1 1) all along its periphery thus forming a sheet of flexible strands, deployable as a corolla around the body (1 1) of said module (1).

[Claim 4] Module (1) according to claim 1, characterized in that the loop-shaped body (1 10) consists of a closed loop and comprises a portion of the hinged or removable loop allowing the opening and the buckle-shaped body closure (1 10).

[Claim 5] Module according to one of claims 2 to 4, characterized in that the body (1 1) has an opening (4) dimensioned to allow the engagement of the support inside the body (1 1) which thus surrounds the support.

[Claim 6] Module according to one of claims 1 to 5, characterized in that the loop-shaped element (1 1) is made of a rigid polymer material, preferably a bio-based polymer, such as a polyamide to castor oil base

[Claim 7] Module according to one of claims 1 to 6, characterized in that the strands (12) consist of fibers of flexible polymer material, preferably a bio-based polymer, such as a polyamide based on oil. castor oil plant.

[Claim s] Artificial aquatic habitat consisting of at least one module (1) according to one of claims 1 to 7 and a submerged support on which the module is fixed by its body in the form of a loop (1 1).

[Claim 9] Artificial aquatic habitat according to claim 8, characterized in that the support is a beacon buoy mooring chain (3) consisting of links (M), each module (1) being fixed on the chain (3) by its body in the form of a loop (1 1) which surrounds said chain (3), a retaining rod (6) being engaged across the loop (1 1) and a link (M) of the chain (3) ).

[Claim 10] A habitat according to claim 9, characterized in that the chain (3) is covered with a protection such as a spiral plastic band.