Seaweed bed creation device

Abstract

To provide a forming apparatus of a seaweed bed which can prevent deposition of sludge or the like, and can realize a state where gametophytes or young sporophytes of various plants can easily take root on a subject to be fixed.SOLUTION: A forming apparatus of seaweed bed 1 is installed on a surface of a subject to be fixed 50 being an artificial object or a natural object, and the forming apparatus of seaweed bed 1 has a seed string 20 to which gametophytes and / or young sporophytes of plants are attached, where the seed string 20 has: a first position 21 which is a part of the seed string 20 and fixed to the surface of the subject to be fixed; a second position 22 which is a part of the seed string 20 different from the first position 21 and fixed to the surface of the subject to be fixed 50; and an intermediate part 23 which extends between the first position 21 and the second position 22. The intermediate part 23 is installed including an area where a separation distance between the seed string 20 and the surface of the subject to be fixed 50 gradually changes with changes of positions from the first position 21 to the second position 22 along the seed string 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a seagrass bed construction device that can be used for seagrass bed restoration and the like.

Background Art

[0002] Conventionally, after construction such as the installation of underwater structures, the restoration of seagrass beds that actively promote the growth of algae is often desired from the perspectives of environmental conservation and regional fisheries promotion. Conventional seagrass bed restoration has been by "transplanting seedlings" or "diffusing zoospores". In "transplanting seedlings", gametophytes of algae collected from other sea areas or gametophytes of algae grown on land were prepared as seedlings (gametophytes attached to a thread or the like), and these were introduced into the water. In "diffusing zoospores", zoospores were diffused from mature thalli placed in a bag-shaped structure.

[0003] These conventional seagrass bed construction methods are carried out as separate operations after the construction work, resulting in high costs and long construction periods. Also, special materials are required, and since they involve underwater work, consideration must be given to safety aspects. Furthermore, in conventional seagrass bed restoration, mainly methods such as transplanting mother algae and fixing plates are used, which are laborious and at the same time, special tools for seaweed growth, for example, underwater bonds, plates, seeding threads, etc. are required. Also, although methods of spreading spores have been attempted in recent years, due to the depletion of the mother algae serving as the supply source due to seashore burning or the like, implementation may be difficult depending on the region or location.

[0004] Furthermore, in conjunction with marine civil engineering works such as preventing erosion caused by tidal currents and waves, and reinforcing the roots, before installing unit-type (filter unit) or mat-type structures in the sea, the gametophytes and sporophytes of algae that have been cultured in advance may be attached to the structures and transplanted. In this case, care must be taken not to adversely affect the gametophytes and sporophytes of the algae during these construction processes. Specifically, careful construction is required to prevent damage from friction to the ropes of the fixed objects (filter units) or panels with attached algae that are attached to the mat-laying structures. Consequently, even under harsh marine weather conditions, this can lead to decreased construction efficiency and prolonged construction periods, which is undesirable in terms of achieving safe construction.

[0005] The following is disclosed as a technique for creating seaweed beds in the ocean, which involves cultivating seaweed larvae on the surface of a filamentous structure installed in the ocean. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2001-275515 [Patent Document 2] Japanese Patent Publication No. 2006-42717 [Patent Document 3] Japanese Patent Publication No. 2003-143999 [Patent Document 4] Japanese Patent Publication No. 2005-333960 [Patent Document 5] Japanese Patent Publication No. 2002-360087 [Patent Document 6] Japanese Patent Publication No. 2021-180630 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The technologies described in Patent Documents 1 to 3 involve placing a substrate, such as a rope on which seaweed larvae are cultivated, into the sea. However, these documents only disclose a static method of installing the substrate, meaning it is installed in a way that prevents movement. As a result, fine particles such as floating sediment in the sea tend to accumulate and adhere to the surface of this substrate. Consequently, sunlight necessary for the growth of gametophytes and larval sporophytes on the rope is blocked, and the fine particles inhibit photosynthesis and respiration of the gametophytes and larval sporophytes on the rope, thus inhibiting their growth.

[0008] Furthermore, Patent Document 4 states that "creating a raised seaweed bed improves tidal flow by raising the (5) concrete block base and (4)(7) the upper base of the steel pillars, resulting in less floating silt on the seaweed and cleaner seaweed leaves." However, even with a raised bed, it is unavoidable that fine particles such as floating silt drifting in the sea will accumulate and adhere to the seaweed, hindering the growth of the seaweed.

[0009] Furthermore, Patent Documents 5 and 6 describe attaching a float to a "cable" or "rope" to make it stand almost vertically in the sea, or suspending the "cable" or "rope" into the sea from a float on the sea surface. In this configuration, the "cable" or "rope" is violently shaken by the ocean currents acting on it, making it easy for growing algae to be torn off the "cable" or "rope". Also, even if the algal body maintains its attachment and enters the subsequent growth process, as the size of the algal leaves grows, the force applied by the ocean currents in the water increases, so the algae tend to be more easily torn off the "cable" or "rope". In addition, because the "cable" or "rope" extends almost vertically, even if the roots of algae growing above try to extend downwards, the algae growing below obstructs them, preventing the roots from extending downwards. Therefore, the roots of growing algae cannot reach structures or rocks installed on the seabed. In this respect as well, the algae are easily torn off from the "cables" or "ropes," and because the "cables" or "ropes" need to be continuously installed, this method is not suitable for restoring seaweed beds that closely resemble nature.

[0010] The objective of this disclosure is to provide a seaweed bed creation device that can prevent the accumulation of sludge and other materials, and that can create conditions that facilitate the attachment of gametophytes and larval sporophytes of various plants to the target object. [Means for solving the problem]

[0011] This disclosure solves the aforementioned problems by the following solutions. For ease of understanding, the embodiments of this disclosure will be described using corresponding reference numerals, but are not limited thereto.

[0012] The first disclosure is, for example, a seaweed bed creation device (1) to be installed on the surface of an object (50) which is an artificial or natural object, as shown in Figures 1 and 2, wherein the creation device (1) has a filamentous body (20) to which the gametophytes and / or larsporophytes of plants are attached, and the filamentous body (20) has a first position (21) which is a part of the filamentous body (20) that is fixed to the surface of the object (50), and a part of the filamentous body (20) that is different from the first position (21) that is fixed to the object (50). The seaweed bed creation device (1) has a second position (22) fixed to the surface of an object (50), and an intermediate portion (23) extending between the first position (21) and the second position (22), wherein the intermediate portion (23) is installed to include a point where the distance between the string-like body (20) and the surface of the object to be fixed (50) gradually changes as the position changes along the string-like body (20) from the first position (21) to the second position (22).

[0013] The second disclosure is a seaweed bed creation device (1) described in the first disclosure, characterized in that, for example, as shown in Figure 3, the intermediate portion (23) has at least a portion where the distance from the fixed object (50) is between 1 cm and 15 cm.

[0014] The third disclosure is a seaweed bed creation device (1) described in the first or second disclosure, characterized in that, for example, as shown in Figures 5 and 6, the first position (21) and the second position (22) are spaced apart on the surface of the fixed object (50), the length of the intermediate portion (23) is longer than the distance between the first position (21) and the second position (22) fixed to the surface of the fixed object (50), and the shape of the intermediate portion (23) includes at least one of the shapes of a U-shape, a semicircle, and a V-shape.

[0015] The fourth disclosure is a seaweed bed creation device (1) described in the first or second disclosure, characterized in that, for example, as shown in Figure 7, the first position (21) and the second position (22) are adjacent to or coincide on the surface of the fixed object (50), the length of the intermediate portion (23) is longer than the distance between the first position (21) and the second position (22) fixed to the surface of the fixed object (50), and the shape of the intermediate portion (23) includes at least one shape from annular and loop-shaped.

[0016] The fifth disclosure is a seaweed bed creation device (1) described in any of the first to fourth disclosures, characterized in that, as shown in Figure 1, it comprises a base member (10) that is directly fixed to the object to be fixed (50), and the first position (21) and the second position (22) are fixed to the surface of the object to be fixed (50) via the base member (10).

[0017] The sixth disclosure is a seaweed bed creation device (1) described in any of the first to fifth disclosures, characterized in that, as shown in Figure 2, the fixed object (50) is a bag material for the bag-type root reinforcement method.

[0018] The seventh disclosure is a seaweed bed construction device (1) described in any one of the first to sixth disclosures. As shown in FIG. 6(c), a float (30) having a buoyancy to float the intermediate portion (23) in water is attached to the intermediate portion (23). The seaweed bed construction device (1) is characterized by this.

[0019] The eighth disclosure is a seaweed bed construction device (1) described in any one of the first to seventh disclosures. As shown in FIG. 8, a plurality of the string-like bodies (20) are arranged so as to intersect, and the intersecting intermediate portions (23) are connected to each other. The seaweed bed construction device (1) is characterized by this.

Effects of the Invention

[0020] According to the present disclosure, it is possible to provide a seaweed bed construction device that can prevent the deposition of sludge and the like and can realize a state in which gametophytes and young sporophytes of various plants are likely to adhere to a fixing object

Brief Description of the Drawings

[0021] [Figure 1] It is a figure which shows 1st Embodiment of the seaweed bed construction apparatus 1 by this indication. [Figure 2] It is a figure which illustrates the use condition of a seaweed bed construction apparatus. [Figure 3] It is a figure which expands and shows the vicinity of one intermediate part 23. [Figure 4] It is a figure which shows an example which arranges a plurality of seaweed bed construction apparatuses 1 in multiple directions. [Figure 5] It is a figure which shows the deformation | transformation form of a seaweed bed construction apparatus. [Figure 6] It is a figure which shows the deformation | transformation form of a seaweed bed construction apparatus. [Figure 7] It is a figure which shows the deformation | transformation form of a seaweed bed construction apparatus. [Figure 8] It is a figure which shows the deformation | transformation form of a seaweed bed construction apparatus. [Figure 9] It is a figure which summarizes test results. [Figure 10]This figure shows a photograph of the seaweed bed creation device 1 taken during the test. [Modes for carrying out the invention]

[0022] The following describes one embodiment for implementing this disclosure with reference to drawings and other materials.

[0023] (First Embodiment) Figure 1 is a diagram showing a first embodiment of the seaweed bed creation device 1 according to this disclosure. Figure 2 is a diagram illustrating the state of use of the seaweed bed creation device. Note that the following diagrams, including Figures 1 and 2, are schematic diagrams, and the size and shape of each part are exaggerated or omitted as appropriate for ease of understanding. In addition, the following description will show specific numerical values, shapes, materials, etc., but these can be changed as appropriate.

[0024] The seaweed bed creation device 1 comprises a main string 10 and a seed string 20, and is installed on the surface of a fixed object 50, which is an artificial or natural object, and used for creating seaweed beds. In this disclosure, "seaweed bed" includes communities of algae, etc. In this disclosure, "creation of a seaweed bed" includes the formation, expansion, regeneration, etc. of seaweed beds in the sea area where the seaweed bed creation device is installed and its surroundings.

[0025] The main cord (base member) 10 can be made of the same cord-like material as the seed cord 20, which will be described later. Alternatively, the main cord 10 may be made of a different cord-like material than the seed cord 20. In this embodiment, the main cord 10 becomes the base member that is directly fixed to the object to be fixed 50.

[0026] The seed string (string-like body) 20 is a string-like body to which the gametophyte and / or larval sporophyte of a plant are attached. The seed string 20 corresponds to a seedling. In this disclosure, by arranging the seed string 20 to satisfy predetermined requirements, the accumulation of sludge and the like is prevented, while a condition is achieved in which the gametophyte and larval sporophyte of various plants can easily attach to the object to be fixed.

[0027] As the seed string 20, vinylon, polyester, or a blend of both is preferable as the material. However, it is not limited to these, and any string, rope, or cord that maintains durability in water and has excellent strength, weather resistance, durability, and chemical resistance may be used. For example, as the seed string 20, strings, ropes, or cords made from cotton, hemp, rayon, polylactic acid, cellulose, polyamide (nylon, etc.), polyester, polyvinyl alcohol (vinylon, etc.), polyethylene, polypropylene, polyvinylidene chloride, aramid, polyarylate, polyacrylonitrile (acrylic fiber), spandex (polyurethane elastic fiber), rubber (urethane rubber, silicone rubber, fluororubber, etc.) can be used. Furthermore, as the seed string 20, any linear body with a certain width that can be placed in water so as to sway appropriately in the water, for example, in the form of cloth or strips, is acceptable. Biodegradable materials can also be used as needed. Therefore, in the claims and specification of this application, "string" and "string-like" include not only the general concepts of "string" and "string-like," but also the described forms of rope, cord, elongated cloth, and strip-like shapes. Furthermore, the thickness of the seed string 20 is preferably about 1 mm to 2.5 mm, but thicker ones may also be used. It is desirable that the seed string 20 can maintain the shape of the intermediate section 23, described later, to some extent in water, and has a degree of stiffness (bending rigidity) that allows it to bend slowly in the water flow. Therefore, the seed string 20 must be selected after careful consideration of its material and thickness, in addition to being able to attach to and subsequently root the gametophyte and / or larval sporophyte of a plant. In this embodiment, a Cremona rope with a diameter of 1.8 mm was used as the seed string 20. Cremona rope is a rope mainly made of vinylon. Note that the diameter is not limited to the above example, and those in the range of 0.5 mm to 20 mm in diameter can be suitably used.

[0028] The plant gametophytes (male or female gametophytes) and / or larsuporophytes attached to the seed string 20 may be any type used for algal seedlings. The gametophytes and / or larsuporophytes may be derived from one or more plant species.

[0029] The plants from which the gametophyte and / or nymphopodium originate are not particularly limited, but among multicellular organisms that reproduce by gametophytes, marine plants such as seaweed are preferred. Seaweed is classified into brown algae, red algae, and green algae, of which brown algae are particularly preferred.

[0030] Among brown algae, the families Laminariaceae, Laminariaceae, Lessoniaceae, and Fucalaceae are important species that form coastal seaweed communities as large seaweeds; therefore, the gametophytes and / or larsupporophytes of the plants in this disclosure are preferably derived from these families. More specifically, the plant gametophyte in this disclosure is preferably derived from the following: Saccharina japonica (Japanese kelp), Saccharina japonica (Japanese kelp), Saccharina japonica (Japanese kelp), Saccharina japonica (Japanese slender kelp), Saccharina japonica (Japanese scallop), Saccharina angustata (Japanese kelp), Saccharina longissima (Japanese kelp), Saccharina coriacea (Japanese kelp), Arthrothamnus bifidus (Japanese kelp), and Saccharina sculpera (Japanese kelp) are all species of the genus Saccharina in the family Laminariaceae, order Laminariales. Wakame (scientific name: Undaria pinnatifida), Hirome (scientific name: Undaria undarioides), and Aowakame (scientific name: Undaria peterseniana) are all species belonging to the genus Undaria in the family Undariaceae, order Laminariales. The following species belong to the genus Ecklonia in the family Lessoniaceae: Ecklonia cava, Ecklonia kurome, Eisenia bicyclis (syn. Ecklonia bicyclis), Ecklonia stolomifera, Undaria undarioides, and Eisenia nipponica. Furthermore, it can be applied to other Fucales species that do not form gametophytes, such as Sargassum horneri, Sargassum fulvellum, and Sargassum fusiforme.

[0031] Any method that can isolate gametophytes from plants can be used, and is not particularly limited. However, when isolating gametophytes from algae, for example, the following methods can be used. First, the reproductive organs (buds, ascocarps, etc.) are excised and washed with sterile filtered seawater, and then the zoospores are released into a container of sterile filtered seawater by a drying treatment. Next, the zoospores are cultured until they settle and form gametophytes. After culturing, under observation with a stereomicroscope, one female or male gametophyte is collected using a pipette, etc., and placed in a culture container (multiplate, etc.). By culturing the female and male gametophytes separately, the female and male gametophytes can be obtained, respectively. Before attaching the female and male gametophytes to the seed string, they may be subjected to tests to confirm their reproductive capacity or treatments to promote the maturation of the gametophytes, as needed.

[0032] For the young sporophyte, a sporophyte that has germinated from a fertilized egg (for example, one measuring 0.03 mm to 300 mm in size) can be used.

[0033] The ratio of gametophytes and / or larval sporophytes attached to the seed stalk is not particularly limited. From the viewpoint of efficiency in seaweed bed creation, it is preferable to attach at least male and female gametophytes to the seed stalk, and more preferably to attach male and female gametophytes in an equal ratio. In such cases, it is preferable that the ratio of male gametophyte colonies to female gametophyte colonies is 1:1 to 1:2.

[0034] The method for attaching the plant's gametophyte and / or larval sporophyte to the seed string is not particularly limited, and any method known for producing seedlings can be employed. For example, any method of bringing a solvent containing a desired amount of gametophyte and / or sporophyte to be attached to the seed string can be used. Such methods of contact include immersing part or all of the seed string in a solvent containing the gametophyte and / or lariosporophyte to impregnate it, or coating or spraying part or all of the seed string with a solvent containing the gametophyte and / or lariosporophyte.

[0035] The solvent used to contain the gametophyte and / or larval sporophyte is not particularly limited as long as it does not hinder the growth of the gametophyte and / or larval sporophyte, but preferred solvents include culture media and sterile filtered seawater. Suitable growing media include PESI medium, commercially available liquid plant fertilizers, and commercially available plant nutrients. Sterilized filtered seawater includes seawater from which solid matter (e.g., particles larger than 1 μm) has been removed and which has been sterilized by any method. The seawater used may be artificial seawater or natural seawater.

[0036] The amount of gametophyte and / or larval sporophyte in the solvent is not particularly limited, but the greater the amount attached to the seed string, the more likely the gametophyte and / or larval sporophyte are to attach to the seed string in a living state, and the more likely the effects of this disclosure are to be achieved.

[0037] The temperature at which the solvent containing the gametophyte and / or sporophyte is brought into contact with the seed filament is not particularly limited, but is usually 16-24°C.

[0038] The time required for contact between the solvent containing the gametophyte and / or lariosporophyte and the seed string is not particularly limited, but from the viewpoint of ensuring sufficient attachment of the gametophyte and / or lariosporophyte to the seed string, it is usually 1 to 6 hours, with a maximum of about 12 hours.

[0039] The seed string 20 has a first position 21, a second position 22, and an intermediate portion 23. The first position 21 is provided on a part of the seed string 20 and is fixed to the surface of the object to be fixed 50. The second position 22 is provided on a different part of the seed string 20 from the first position 21, at a distance from the first position 21, and is fixed to the surface of the object to be fixed 50. Here, "fixed to the surface of the object to be fixed 50" includes not only a form in which it is directly fixed to the surface of the object to be fixed 50, but also a configuration in which it is indirectly fixed. In this embodiment, both the first position 21 and the second position 22 are fixed to the main string 10, and the main string 10 is directly fixed to the surface of the object to be fixed 50, so the first position 21 and the second position 22 are indirectly fixed to the surface of the object to be fixed 50. That is, in this embodiment, the first position 21 and the second position 22 are fixed to the surface of the object to be fixed 50 via the main string 10. In addition to fixing via the main string 10, or instead of fixing via the main string 10, the seed string 20 may be directly fixed to the surface of the object to be fixed 50 at the first position 21 and the second position 22.

[0040] The main string 10 and seed string 20 are fixed to the object to be fixed 50 using adhesive or fastening devices. For example, to fix the main string 10 and seed string 20 to the object to be fixed 50, adhesives that function in water, cable ties, metal wires, vinyl wires, etc., can be used. Also, if the object to be fixed 50 is a heavy concrete or other member of considerable size, such as an artificial reef or breakwater, separate ropes or other wires may be wrapped around it at regular intervals, and the main string 10 and seed string 20 may be fixed to these separate ropes or other wires. In any of the fixing methods, the seaweed bed creation device 1 is fixed to the object to be fixed 50 with the intermediate section 23 spaced apart from the object to be fixed 50 and protruding into the water. In this embodiment, in order to space the intermediate section 23 apart from the object to be fixed 50, the cross-sectional shape of the seed string 20 may be, for example, a rectangle, square, triangle, trapezoid, ellipse, etc. Furthermore, in this embodiment, in order to separate the intermediate portion 23 from the object to be fixed 50, for example, heat may be applied to the seed string 20 to thermally deform it into the desired shape, a material with sufficient rigidity to allow the seed string 20 to sway may be used, a thin rod-shaped bamboo or wood may be installed at the base or rising portion of the seed string 20 to maintain its shape, or an extremely thin wire or the like may be wrapped around the seed string 20 to process its shape. In addition, as a modified form described later, a float may be provided on the intermediate portion 23 as shown in Figure 6(c).

[0041] Figure 3 is a magnified view of the vicinity of one intermediate section 23. The intermediate section 23 extends between the first position 21 and the second position 22. In this embodiment, the first position 21 and the second position 22 are spaced apart on the surface of the object to be fixed 50. Also, the length L20 of the intermediate section 23 is longer than the length L10 between the first position 21 and the second position 22, which are fixed to the surface of the object to be fixed 50. Therefore, the intermediate section 23 is curved and formed in a mountain shape (approximately U-shape). In this embodiment, three sets of the combination of the first position 21, the second position 22, and the intermediate section 23 are arranged side by side. The three sets of intermediate sections 23 are formed by a single connected string.

[0042] Further, the intermediate portion 23 is installed including a location where the separation distance between the seed string 20 (intermediate portion 23) and the surface of the object to be fixed gradually changes as the position changes along the seed string 20 (intermediate portion 23) from the first position 21 to the second position 22. Explaining with reference to FIG. 3, the distance from the seed string 20 (intermediate portion 23) to the parent string 10 is h1 in the figure at a position close to the first position 21, but as the position changes from that position toward the second position 22, the distance gradually becomes longer and, for example, becomes h2 in the figure. As is clear from FIG. 3, h1 < h2. Further, as the position changes from that position toward the second position 22, the distance from the seed string 20 (intermediate portion 23) to the parent string 10 becomes h3, which is the maximum value, near the intermediate position between the first position 21 and the second position 22. After that, conversely to the previous case, the distance from the seed string 20 (intermediate portion 23) to the parent string 10 gradually decreases as it approaches the second position 22. Although the object to be fixed 50 is not shown in FIG. 3 for ease of viewing the figure, since the parent string 10 is attached along the surface of the object to be fixed 50, the position of this parent string 10 can be regarded as the surface position of the object to be fixed 50.

[0043] The distance h3 at which the intermediate section 23 is furthest from the surface of the object to be fixed 50 is preferably between 1 cm and 15 cm, considering the work efficiency when installing the seaweed bed creation device 1 in the water and the ease with which algae can take root. Furthermore, it is even more preferable that the above distance h3 be between 6 cm and 10 cm. In this embodiment, the distance h3 was set to 8 cm, which is considered to be the most appropriate distance. By installing the intermediate section 23 by gradually moving it away from the surface of the object to be fixed 50 to the above distance, the intermediate section 23 can sway slowly in the water with an appropriate amount of displacement. Therefore, even if fine particles (floating sediment) in the seawater accumulate or adhere to the intermediate section 23, the fine particles will be shaken off from the intermediate section 23 afterward. In addition, it can protect against creeping predatory organisms such as sea urchins. Furthermore, since the intermediate section 23 does not experience rapid displacement or shaking in the water, it is possible to prevent growing sporophytes, whose roots have not yet firmly adhered to the intermediate section 23, from detaching from the intermediate section 23. However, if the distance h3 is made larger than 15 cm, there is a high possibility that the algal body will be washed away before its roots can reach the object 50 to which it is fixed.

[0044] Furthermore, since the distance from the intermediate section 23 to the surface of the object to be fixed 50 varies, there is a very high probability that there is a portion that is at an appropriate distance for the attachment sites (roots) of the growing algae to attach to the object to be fixed 50. As the algae grow, the larger the algal bodies attached to the intermediate section 23 become, the more they are affected by waves, increasing the likelihood that the roots of the algal bodies attached to the intermediate section 23 will detach. Also, as the distance from the intermediate section 23 to the surface of the object to be fixed 50 increases, not only does it become more difficult for the attachment sites (roots) to attach to the object to be fixed 50, but the algal bodies also become more susceptible to the effects of waves, and the roots of the algal bodies tend to detach more easily. The appropriate distance for the attachment sites (roots) to attach to the object to be fixed 50 differs depending on the type of algae and individual differences, but with the configuration of this embodiment, there is a possibility that there is a portion that is at an appropriate distance due to the above configuration. Therefore, the possibility of the algae ultimately attaching to the object to be fixed 50 can be greatly increased. As the algal bodies attached to the intermediate section 23 grow, their roots extend and reach the object to be fixed 50. If the roots can then take root in the object to be fixed 50, the loss of the algal bodies can be prevented.

[0045] Furthermore, the algal bodies attached to the intermediate section 23 grow in approximately 30 to 90 days, and root elongation is also observed. At this time, the weight of the algal bodies themselves may cause the intermediate section 23 to come close to the anchoring object 50, allowing the algal bodies to take root on the anchoring object 50 and continue growing. At this stage, the effect of the accumulation of fine particles is almost negligible, so the survival rate improves. This makes it possible to significantly accelerate the regeneration of the seaweed bed.

[0046] The above mechanisms work together to maintain healthy growth of the gametophyte and larval sporophyte, and facilitate the attachment of attachment sites (roots) to the anchoring object 50 during the algal growth process. Thus, the algal bed creation device 1 of this embodiment provides conditions suitable for the attachment of algal roots to the anchoring object 50, and can also prevent the accumulation of floating sediment.

[0047] In this embodiment, the object to be fixed 50 is a bag material (filter unit) for a bag-type root reinforcement method, which is submerged in water with a filling material such as pebbles or crushed stone. The object to which the seaweed bed creation device 1 of this embodiment can be applied is any object that exists in water and does not move easily due to water currents, etc. Examples include gabions, artificial reefs, offshore breakwaters, piers, breakwaters, and substrates for cultivating seaweed beds and corals installed on the seabed, but it is not limited to these, and any artificial or natural objects installed in a place where it is necessary to cultivate a seaweed bed can be appropriately selected.

[0048] Here, if the direction of the main water flow relative to the fixed object 50 is unknown, or if water flows in various directions are expected, it is advisable to arrange multiple seaweed bed creation devices 1 facing in multiple directions. This is because, depending on the direction of the water flow, there may be directions in which the intermediate section 23 is more likely to tip over. Figure 4 shows an example of arranging multiple seaweed bed creation devices 1 facing in multiple directions. In the example shown in Figure 4, multiple seaweed bed creation devices 1 are arranged so that their longitudinal directions are arranged radially. With such an arrangement, it is easier and more reliable to arrange multiple seaweed bed creation devices 1 facing in various directions than by arranging them randomly.

[0049] (Transformed form) Figures 5 to 8 show modified forms of the seaweed bed creation device. In the following description, we will focus on the parts of the modified form that differ from the first embodiment, and parts that perform the same function as the first embodiment described above will be denoted by the same reference numerals, and redundant explanations will be omitted as appropriate.

[0050] As shown in Figure 5(a), a single seed string 20 may be formed in a roughly D shape, and in addition to the intermediate section 23, a string section 24 may be provided that connects the first position 21 and the second position 22 at a shorter distance than the intermediate section 23. In this configuration, the main string 10 of the first embodiment does not exist. In this configuration, the string section 24 is fixed along the object to be fixed 50, and the intermediate section 23 is spaced apart from the object to be fixed 50 and protrudes into the water. In this configuration, the shape of the intermediate section 23 can be formed in advance. Furthermore, in this configuration, the seed string 20 can be cut to a predetermined length at the construction site and the seaweed bed creation device can be manufactured on the spot. In this case, the cut seed string 20 is used to space the top of the intermediate section 23 from the object to be fixed 50 by the preferred distance shown above, and the string section 24 is placed along the object to be fixed 50 to fix the first position 21 and the second position 22 to the object to be fixed 50. In this configuration, to separate the intermediate portion 23 from the object to be fixed 50, for example, heat can be applied to the seed string 20 to thermally deform it into the desired shape, a material with sufficient rigidity to allow the seed string 20 to sway can be used, a thin rod-shaped bamboo or wood can be installed at the base or rising portion of the seed string 20 to maintain its shape, or an extremely thin wire or the like can be wrapped around the seed string 20 to shape it. Alternatively, as shown in Figure 6(c), a float can be provided in the intermediate portion 23 as a modified configuration described later.

[0051] As shown in Figure 5(b), a single seed string 20 may be made into a roughly U-shape, with the ends of the U-shape fixed to the object to be fixed 50 as the first position 21 and the second position 22, respectively, and the intermediate part 23 spaced apart from the object to be fixed 50 and protruding into the water. In this configuration, the main string 10 of the first embodiment does not exist. In this configuration, the seed string 20 can be cut to a predetermined length at the construction site and the seaweed bed creation device can be manufactured on the spot. In this case, the cut seed string 20 is used to space the top of the intermediate part 23 from the object to be fixed 50 by the preferred distance shown above, and the first position 21 and the second position 22 are fixed to the object to be fixed 50. Alternatively, the U-shaped intermediate part 23 may be pre-formed by folding or bending it on land or on a ship before working in the water. In this configuration, to separate the intermediate portion 23 from the object to be fixed 50, for example, heat can be applied to the seed string 20 to thermally deform it into the desired shape, a material with sufficient rigidity to allow the seed string 20 to sway can be used, a thin rod-shaped bamboo or wood can be installed at the base or rising portion of the seed string 20 to maintain its shape, or an extremely thin wire or the like can be wrapped around the seed string 20 to shape it. Alternatively, as shown in Figure 6(c), a float can be provided in the intermediate portion 23 as a modified configuration described later.

[0052] Furthermore, by further developing the configuration shown in Figure 5(b), as shown in Figure 5(c), a single seed string 20 may be made into a roughly U-shape at multiple locations to create multiple intermediate sections 23 in a continuous manner, and the ends of both ends of the U-shape may be fixed to the object to be fixed as the first position 21 and the second position 22. In this case as well, the intermediate sections 23 are spaced apart from the object to be fixed 50 and protrude into the water. In this configuration, the main string 10 as in the first embodiment does not exist. In this configuration, the seed string 20 can be cut to a predetermined length at the construction site and the seaweed bed creation device can be manufactured on the spot. In this case, the cut seed string 20 is used to space the tops of the multiple intermediate sections 23 apart from the object to be fixed 50 at the preferred distances shown above, and the first position 21 and the second position 22 are fixed to the object to be fixed 50. In terms of work, multiple intermediate sections 23 can be easily manufactured by working sequentially from one end. Furthermore, before working underwater, the intermediate sections 23 may be pre-formed by folding or bending on land or on a ship to create multiple U-shaped intermediate sections 23. In order to separate the intermediate sections 23 from the object to be fixed 50 in this configuration, for example, heat may be applied to the seed string 20 to thermally deform it into the desired shape, a material with sufficient rigidity to allow the seed string 20 to sway may be used, a thin rod-shaped bamboo or wood may be installed at the base or rising part of the seed string 20 to maintain its shape, or an extremely thin wire or the like may be wrapped around the seed string 20 to process its shape. In addition, as shown in Figure 6(c), a float may be provided on the intermediate section 23 as a modified form described later.

[0053] As shown in Figure 6(a), in a configuration similar to the first embodiment, the shape of the intermediate portion 23 may be formed in a U-shape (semi-elliptical shape). Also, as shown in Figure 6(b), in a configuration similar to the first embodiment, the shape of the intermediate portion 23 may be formed in a semi-circular shape.

[0054] Furthermore, as shown in Figure 6(c), a float 30 may be attached to the intermediate section 23. This configuration allows the intermediate section 23 to maintain a sufficient distance from the object to be fixed 50. In particular, in this case, as shown in Figure 6(c), the intermediate section 23 may be configured in a substantially straight line.

[0055] Figure 7(a) shows a modified form in a perspective view. In the embodiments and modified forms described earlier, the first position 21 and the second position 22 were spaced apart. However, as shown in Figure 7(a), the first position 21 and the second position 22 may be placed adjacent to each other or at the same position. In this case, the intermediate section 23 is configured in a loop or ring shape. In this form, the main string 10 as in the first embodiment does not exist. In this form, the seed string 20 can be cut to a predetermined length at the construction site and the seaweed bed creation device can be manufactured on the spot. In this case, using the cut seed string 20, the top of the intermediate section 23 is spaced at the preferred distance shown earlier from the object to be fixed 50, and both ends of the seed string are designated as the first position 21 and the second position 22, respectively. The first position 21 and the second position 22 are either adjacent to each other or at the same position and fixed to the object to be fixed 50. Furthermore, before working underwater, the intermediate section 23 may be pre-formed with creases or bends on land or on a ship to create a loop or ring shape. In order to separate the intermediate section 23 from the object to be fixed 50 in this form, for example, heat may be applied to the seed string 20 to thermally deform it into the desired shape, a material with sufficient rigidity to allow the seed string 20 to sway may be used, a thin rod-shaped bamboo or wood may be installed at the base or rising part of the seed string 20 to maintain its shape, or an extremely thin wire or the like may be wrapped around the seed string 20 to process its shape. In addition, as a modified form described later, a float may be provided on the intermediate section 23 as shown in Figure 6(c).

[0056] Furthermore, in the case where the intermediate portion 23 is loop-shaped or annular, multiple intermediate portions 23 may be formed by a single seed string 20, as shown in Figure 7(b). Also, the shape of the loop-shaped or annular intermediate portion 23 may be a roughly circular shape as shown in Figure 7(b), or a roughly elliptical shape as shown in Figure 7(c).

[0057] As shown in Figure 8(a), two seaweed bed creation devices 1-1 and 1-2 may be arranged in a crisscross pattern, and a connecting section 25 may be provided near the apex of each seed string 20-1 and 20-2 to connect them. Alternatively, as shown in Figure 8(b), the seed strings 20-1 and 20-2 forming the intermediate section 23 may be formed in a straight line. In these configurations shown in Figures 8(a) and 8(b), since the seed strings 20-1 and 20-2 are connected at the connecting section 25, it is easier to maintain a state where the intermediate sections 23 of each seed string 20-1 and 20-2 are separated from the object to be fixed 50. Note that although the configurations shown in Figures 8(a) and 8(b) illustrate configurations with main strings 10-1 and 10-2, the main strings 10-1 and 10-2 may be omitted.

[0058] (Test verification) A seaweed bed creation device 1, as shown in Figure 5(a) above, was actually installed in the sea, and an experiment was conducted to observe the growth of algae over a long period of time. The seed string 20 had 0.1-0.3 mm sporophytes of Ecklonia ciliata pre-attached to it. The string portion 24 was fixed to a bag material for a bag-type root reinforcement method that was submerged in the sea and used as the fixing target object 50, and the apex of the intermediate portion 23 was positioned 8 cm away from the fixing target object 50. Since sporophytes were also attached to the string portion 24, this string portion 24 could be considered as a comparison part to verify the effect of positioning the intermediate portion 23 at a distance from the fixing target object 50. For the intermediate portion 23 and the string portion 24, the sporophyte survival rate and average algal length were checked at 30, 60, and 90 days after installation.

[0059] Figure 9 is a summary of the test results. Figure 9(a) is a table summarizing the experimental data, Figure 9(b) is a graph summarizing the sporophyte survival rate, and Figure 9(c) is a graph summarizing the average algal length. Figure 10 is a photograph of the algal bed creation device 1 taken during the test. Figure 10(a) shows the start date of the test (day 0), Figure 10(b) shows the 30th day after the start of the test, Figure 10(c) shows the 60th day after the start of the test, and Figure 10(b) shows the 90th day after the start of the test.

[0060] On day 30 after the start of the experiment, no thallus was observed in the comparison section (string section 24), but the thallus in the intermediate section 23 had grown to an average length of 32m, with a maximum growth of 40mm (Figure 10(b)). Furthermore, on day 60 after the start of the experiment, the thallus in the intermediate section 23 had grown to an average length of 105m, with a maximum growth of 200mm (Figure 10(c)). At this 60-day mark, the sporophyte survival rate, relative to day 30, was 90%. Moreover, on day 90 after the start of the experiment, the thallus in the intermediate section 23 had grown to an average length of 165m (Figure 10(c)). At this 90-day mark, the sporophyte survival rate, relative to day 30, was 80%.

[0061] As described above, the seaweed bed creation device 1 of this embodiment has at least some locations where the intermediate section 23 is separated from the fixed object 50 by a distance of 1 cm or more and 15 cm or less. This allows the intermediate section 23 to sway slowly in the water with an appropriate amount of displacement, protecting the algae from the accumulation of floating sediment and creeping predatory organisms such as sea urchins. Furthermore, because the distance from the intermediate section 23 to the surface of the fixed object 50 varies, there is a high possibility that there are parts where the distance is appropriate for the attachment sites (roots) of the growing algae to attach to the fixed object 50, thereby increasing the probability that the roots of the algae will attach to the fixed object 50.

[0062] The embodiments and variations described above can be used in combination as appropriate, but a detailed explanation is omitted. Furthermore, this disclosure is not limited to the embodiments described above. [Explanation of Symbols]

[0063] 1. Equipment for creating seaweed beds 10 Main strap 20 types of strings 21 First position 22 Second position 23 Middle section 24 string section 25 Connection part 30 floats 50 Objects to be fixed

Claims

1. A device for creating seaweed beds, which is installed on the surface of a fixed object that is either artificial or natural, The aforementioned planting device consists of a string-like structure to which the gametophyte and / or sporophyte of a plant are attached. The string-like body has a first position which is part of the string-like body and fixed to the surface of the object to be fixed, a second position which is part of the string-like body different from the first position and fixed to the surface of the object to be fixed, and an intermediate portion which extends between the first position and the second position. The aforementioned intermediate section is installed to include a location where the distance between the string-like body and the surface of the object to be fixed gradually changes as the position changes along the string-like body from the first position to the second position.

2. In the seaweed bed creation apparatus according to claim 1, The aforementioned intermediate portion has at least a portion where the distance from the fixed object is 1 cm or more and 15 cm or less. A seaweed bed creation device characterized by the following features.

3. In the seaweed bed creation apparatus according to claim 1 or claim 2, The first position and the second position are spaced apart on the surface of the object to be fixed. The length of the intermediate portion is longer than the distance between the first position and the second position on which it is fixed to the surface of the object to be fixed. The shape of the intermediate portion includes at least one shape from among U-shaped, semicircular, and V-shaped. A seaweed bed creation device characterized by the following features.

4. In the seaweed bed creation apparatus according to claim 1 or claim 2, The first position and the second position are adjacent to or coincide on the surface of the object to be fixed. The length of the intermediate portion is longer than the distance between the first position and the second position on which it is fixed to the surface of the object to be fixed. The shape of the intermediate portion includes at least one shape from annular and loop-shaped. A seaweed bed creation device characterized by the following features.

5. In the seaweed bed creation apparatus according to claim 1 or claim 2, It comprises a base member that is directly fixed to the object to be fixed, The first position and the second position are fixed to the surface of the object to be fixed via the base member. A seaweed bed creation device characterized by the following features.

6. In the seaweed bed creation apparatus according to claim 1 or claim 2, The object to be fixed is a bag material for the bag-type foundation reinforcement method. A seaweed bed creation device characterized by the following features.

7. In the seaweed bed creation apparatus according to claim 1 or claim 2, The intermediate portion is fitted with a float that has buoyancy to cause the intermediate portion to float in water. A seaweed bed creation device characterized by the following features.

8. In the seaweed bed creation apparatus according to claim 1 or claim 2, The aforementioned string-like body is arranged in a manner in which multiple strands intersect. The intersecting intermediate parts are connected to each other. A seaweed bed creation device characterized by the following features.

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