JP6835341B1 - How to create a seaweed fishing ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To create a sustainable seaweed fishing ground that is easy to maintain and manage and supplies natural spores in a fishing ground inhabited by herbivores. SOLUTION: The standing rope substrate 100 and the bottom connecting facility 200 installed on the upper surface of a reef or the like on the seabed are provided. The standing rope substrate 100 is installed so that the rope extends from the seabed toward the sea surface by a float. The standing rope substrate 100 is arranged so that the spores from the natural mother algae grow in the path through which the spores flow in the sea. The vertical rope substrate 100 and the bottom connecting facility 200 are installed close to each other. The bottom connecting facility 200 has ropes 201a to 201c arranged so as to extend in the land-offshore direction above the upper surface of a reef or the like on the seabed. The ropes 201a to 201c are arranged so that the spores from the mother algae that have settled on the standing rope substrate 100 grow in the path through the sea. When the seaweed that has settled on the ropes 201a to 201c grows, it reaches the reefs on the seabed. [Selection diagram] Fig. 6

Description

The present invention relates to a method for creating a seaweed fishing ground by growing seaweed such as kelp in a fishing ground where herbivores inhabit.

Patent Document 1 is an example of a method for growing seaweed such as kelp. In Patent Document 1, a substrate (growth net) on which seaweed spores are pre-established is installed on the seabed.

JP-A-2002-330651

According to the method of Patent Document 1, it is necessary to collect seedlings prior to the installation of the facility. For example, it is necessary to carry out a complicated process such as collecting mother algae capable of releasing spores, allowing spores from the mother algae to grow on a substrate in a water tank or the like, and then placing the substrate on the seabed. As described above, in the method of Patent Document 1, there is a possibility that the step at the stage of introducing the substrate cannot be easily carried out. Therefore, it is difficult to secure a substrate of an appropriate scale and it is difficult to grow a sufficient amount of seaweed, which is not suitable for the construction of fishing grounds. In addition, due to the recent shortage of seaweed, it is difficult to secure sufficient spores for growth on the substrate. Therefore, it may not be possible to secure a sufficient substrate to which spores are attached, and it may not be possible to install a substrate of an appropriate scale. Furthermore, since the substrate is installed on the seabed, it is easily exposed to feeding damage by herbivores such as sea urchins that live on the seabed. Therefore, even if seaweed grows on the substrate, it cannot be maintained for a long period of time. Due to these problems, the method of Patent Document 1 may not be able to create a sustainable and sufficient-scale fishing ground.

The issues of Cited Document 1 are as follows in more detail. When a fishing ground is created by the method of Cited Document 1, the entire facility tends to be large, and the netting and fixing materials used tend to be large-scale. In addition, when carrying out the seedling collection process, management after immersing the facility in a water tank (pool, etc.) filled with spore solution (for example, shortening the transportation time, preventing air drying and rubbing of spores collected on a net) Because of the difficulty, such a method cannot be adopted, and a method of attaching a seed thread may be a candidate instead. However, even with this method, in the work of attaching the seed yarn to a large-scale net, it is necessary to carry out the work in a short time so that the seed yarn does not dry, so that the work on land is difficult. On the other hand, it is still difficult because it requires a huge amount of time and manpower to carry out underwater. Furthermore, in water, when a net with an area in the bedrock sediment is expanded, a uniform tension shape (shape of the net is taut) due to the elongation of the net material as the distance from the periphery to the center of the net increases. ) Becomes difficult to keep. The growth allowance of this net causes the net laid on the seabed to sway due to waves and swells. In addition, this causes the net to be rubbed, and the mesh is likely to be damaged in a short time, and further, damage such as tearing of the net is likely to occur due to storms when a typhoon, a low pressure, or the like occurs. Especially when the purpose is to grow seaweed, the depth of the fishing ground is shallow, so the damage to the facilities installed in the fishing ground is likely to increase. On the other hand, when the bottom sediment is sandy mud, the netting is buried in the sandy mud and stabilized by increasing the specific gravity of the netting. However, when the substrate of the net is embedded, the amount of light required for germination and growth of seedlings that grow on the substrate is insufficient. As described above, the method of Cited Document 1 has many problems as a method for creating a seaweed fishing ground.

An object of the present invention is to provide a method for creating a sustainable seaweed fishing ground that is easy to maintain and manage and supplies natural spores in a fishing ground inhabited by herbivores.

The method for creating a seaweed fishing ground of the present invention is a method for creating a seaweed fishing ground using a first substrate and a second substrate in a fishing ground where predators inhabit, and the first substrate is formed by a first fixing bracket. It has a first string-shaped member whose one end is fixed to a natural or artificially installed object on the seabed, and a floating member fixed to the other end of the first string-shaped member, and the second substrate is , It has a second string-like member that is fixed to a natural object or artificial installation on the seabed by a second fixing bracket, and the first string-like member is in the path through which spores from natural algae flow through the sea. The first substrate is placed so that the first string-shaped member extends from one end thereof toward the sea surface due to the buoyancy force of the floating member, and spores from the mother algae are collected from the first string-shaped member. A step of growing seaweed in the first string-shaped member while suppressing feeding damage by the phytophagous animal by swaying the first string-shaped member due to the influence of waves, and a step of growing seaweed in the first string-shaped member, and the first substrate. The second string-like member is arranged in the path through which spores from the mother algae that have settled on the seabed flow, and the second string-like member extends in the offshore direction above the natural or artificial installation on the seabed. The second substrate is placed in the seaweed, and the spores from the mother algae are allowed to grow on the second string-like member, and at least a part of the seaweed grown in the second string-like member is a natural product on the seabed or It is provided with a step of feeding the predator by reaching the upper surface of the artificial installation. Further, in the first aspect of the present invention, the first string-shaped member has a small diameter portion and a large diameter portion which are portions having different thicknesses from each other, and the small diameter portion is the first. It is located above the first fixing bracket in the string-shaped member. Further, in the second aspect of the present invention, when spores from the natural mother algae are settled, many of the first substrates are placed on the downstream side as compared with the upstream side with respect to the predominant coastal current. In the third aspect of the present invention, the second fixing bracket is inserted into a hole formed in the upper surface of a natural product or an artificial installation on the seabed, and a portion above the third insertion portion. The second fixing brackets are arranged in a row in the land-offshore direction in a plan view, and the second string-shaped members are arranged in each of the plurality of second fixing brackets. It is fixed to the main body.

According to the method for creating a seaweed fishing ground of the present invention, first, spores from natural mother algae are settled on the first substrate. The installation of the first substrate can be carried out by a simple method of fixing the first string-shaped member to which the floating member is fixed by a fixing metal fitting. In addition, the first string-like member is placed in the path through which spores from natural mother algae flow through the sea. Therefore, it is easy to place the first substrate at an appropriate position where spores from natural mother algae can be formed. Further, the first substrate is arranged so that the first string-like member extends from the seabed toward the sea surface. Since the first string-shaped member arranged in this way sways under the influence of waves, the seaweed that has settled on the first string-shaped member is less likely to be damaged by herbivores living on the seabed. Therefore, it is easy to reliably protect and grow seaweed to the stage where spores can be released in the first substrate.

Next, the seaweed that has settled on the first substrate is used as the mother algae, and the spores from the mother algae are further settled on the second substrate. The first substrate may be used as it is at the position where the seedlings were collected from the natural mother algae, or may be moved to a place separated from the seedlings or a new fishing ground. As described above, the first substrate has a simple structure in which one end of the first string-shaped member is fixed by the fixing bracket. Therefore, it is easy to move the first string-shaped member on which seaweed has settled to another place and use it. In this case, it is efficient to use the metal fittings installed at the seedling collection place and the relocation destination without moving the metal fittings. The second substrate has a simple structure in which the second string-like member is installed on a natural product or an artificial installation on the seabed so as to extend in the land-offshore direction by a fixing bracket. Therefore, it is easy to expand the scale of the facility by a simple method of extending the second string-shaped member. In addition, the second string-shaped member is arranged above the natural product or artificially installed object on the seabed. Therefore, the seaweed does not reach the upper surface (near) of the natural product or the artificially installed object during the period until the seaweed grows and extends in the second string-shaped member. In addition, since the second string-like member extends in the water offshore, the flow of water around the substrate derived from the waves constantly suppresses the feeding behavior of the herbivore, and the second string-like member (substrate). ) Upset the seaweeds that grow on. Due to this agitation, seaweed beats herbivores and suppresses their feeding behavior. Therefore, feeding damage caused by herbivores such as sea urchins crawling on the substrate and feeding on seaweed is greatly suppressed. Then, when the seaweed grows, a part of it reaches the natural products or artificial installations on the seabed and becomes the target of feeding of herbivores in a state where the amount of feed is increased. Further, from the first viewpoint, it is difficult for herbivores such as sea urchins living on the seabed to crawl up in the small diameter part, which is more likely to shake due to waves than the large diameter part. Further, since the wave resistance acts strongly on the large diameter portion at the upper part, the small diameter portion is more likely to shake. Therefore, it is difficult for herbivores to reach the large diameter portion above. Therefore, feeding damage by herbivores to seaweeds that have settled on the large diameter portion is suppressed. According to the second viewpoint, more spores released from the mother algae flow out and diffuse to the downstream side than to the upstream side due to the coastal flow. Therefore, by installing a large amount of the first substrate on the downstream side as compared with the upstream side at a distance from the mother algae, such spores can be more reliably and efficiently settled on the first substrate. In the present invention, "installing more of the first substrate on the downstream side than on the upstream side with respect to the predominant coastal flow" means that the first substrate is located upstream of the mother alga (or the center of the mother algae group). It means that the first substrate is installed so that the number of the first substrates located on the downstream side of the one substrate increases. In addition, the predominant coastal flow means a predominant coastal flow during the period of seedling collection on the first substrate. According to the third viewpoint, the second string-shaped member can be fixed by the second fixing bracket so as to be separated upward from the natural product or the artificially installed object with a simple structure.

As described above, in the present invention, it is possible to prevent the settled seaweed from being damaged by the herbivore while appropriately growing the spores released by the natural mother algae on the first substrate. As a result, spores supplied from a limited number of natural mother algae can be protected and grown, and seaweed can be reliably grown up to the stage of releasing spores. In addition, spores from mother algae grown on the first substrate are settled on the second substrate. The first substrate can also be moved to a place where the fishing ground is created and expanded. In the second substrate, feeding damage by herbivores can be suppressed until the seaweed grows sufficiently. Further, since the second substrate can provide a new epiphytic substrate by stretching the second string-like member, the scale can be easily expanded. As a result, in the present invention, it is possible to create a seaweed fishing ground of a sufficient scale while continuously protecting and growing seaweed for a long period of time while suppressing feeding damage by herbivores and appropriately avoiding it. , The fishing ground can be used as a feeding ground for herbivores. In addition, large-scale facilities such as those in the prior art are likely to be unnecessary, and maintenance and management are facilitated.

Further, in the present invention, it is preferable that the floating member has a spindle shape and the first string-shaped member extends from one end of the spindle shape. As a result, the floating member is likely to be arranged so that the long direction of the floating member flutters in the same direction as the flow due to the waves. Therefore, the resistance of the floating member to the waves is greatly reduced. Therefore, it is possible to prevent the first substrate from being damaged or flowing out due to waves.

Further, in the present invention, the first string-shaped member has a string-shaped first member extending across both the small-diameter portion and the large-diameter portion, and the first member along the first member. It is preferable to have a string-shaped second member that forms the large diameter portion by being combined. When a small-diameter portion and a large-diameter portion are provided in the first string-shaped member, a difference in the period of swaying due to waves occurs between the portions having different thicknesses. Due to such a difference, if a large-diameter portion and a small-diameter portion are formed by connecting the ends of the thick string-shaped member and the thin string-shaped member, the small-diameter portion will suffer from bending fatigue or the like in the vicinity of the connecting portion. May break due to. On the other hand, as described above, since the second member is combined with the first member (for example, twisted with each other), bending fatigue of the connecting portion as described above is significantly suppressed. A rope having a large diameter (not in the shape of a twisted string) may be attached to the large diameter portion.

Further, in the present invention, the first fixing bracket is unidirectionally inserted into a connecting portion to which one end of the first string-shaped member is connected and a hole formed in the natural product or the artificial installation object. It has a first insertion portion and a second insertion portion, and the distance between the first insertion portion and the connection portion in a direction orthogonal to the one direction is such that the distance between the second insertion portion and the connection portion is large. It is preferably greater than the distance between. A tensile load due to waves is generated in the first fixing bracket through the first string-shaped member. The direction of this tensile load frequently fluctuates in various directions as the floating member moves on the waves. On the other hand, as described above, not only the second insertion portion but also the first insertion portion is provided and is inserted into a hole of a natural product or an artificially installed object. As a result, the first insertion portion generates a bearing force in the insertion direction against the tensile load that fluctuates as described above. As a result, deformation and displacement of the entire first fixing bracket are suppressed, and strength and durability are ensured. Further, even if the first insertion portion is displaced or deformed, the fixing of the first fixing bracket is maintained due to the frictional resistance between the second insertion portion and the wall surface of the hole. In this way, the first substrate is firmly fixed to the natural product or the artificial installation by the first fixing bracket.

Further, in the present invention, the first fixing bracket has one rod-shaped member, and one end of the rod-shaped member is bent in one direction to form the first insertion portion. The other end of the rod-shaped member is formed, and a curved portion curved in a direction opposite to the one direction is formed as the connecting portion, and a straight portion connecting the curved portion and the one end portion. It is preferable that the second insertion portion is formed so as to project in the one direction from the curved portion by being bent in the one direction so as to intersect with the curved portion. For example, if the first substrate is fixed with a conventional anchor pin and eye nut instead of the first fixing bracket, since these two members are usually composed of dissimilar metals, corrosion progresses at the contact portion of the members. It will be easier to do. On the other hand, as described above, by using the first fixing bracket composed of one rod-shaped member, corrosion is avoided and the fixed state of the first substrate is maintained for a long period of time.

Further, in the present invention, the second fixing bracket has an intersecting portion intersecting with the main body portion, and the plurality of the second string-shaped members are separated from each other in the horizontal direction . It is preferable that the two fixing brackets are fixed to each of the intersections. According to this, a plurality of second string-shaped members are fixed to each intersection of the second fixing brackets arranged in a row. Therefore, more seaweed can be settled and grown on the second substrate as compared with the case where only one second string-shaped member is fixed to the second fixing metal fittings arranged in a row.

Further, in the present invention, the fourth insertion portion inserted into the hole formed on the upper surface of the natural product or artificially installed object on the seabed is separated from the third insertion portion in the direction in which the main body portion intersects with the extending direction. It is preferable that it is provided so as to do so. According to this, since the two insertion portions are inserted, the second fixing bracket is firmly fixed without rotating.

It is a front view of the standing rope substrate used for the seaweed bed reef according to one embodiment of the present invention. It is a figure which shows the state which partially decomposed the standing rope substrate of FIG. It is a front view of the fixing metal fitting for fixing the standing rope substrate of FIG. 1 to a reef or the like. It is a perspective view of the fixing metal fitting of FIG. It is a top view which shows the installation example of the standing rope substrate of FIG. It is a top view of the seagrass bed reef installed using the standing rope substrate of FIG. It is a front view of the bottom connecting facility used for the seagrass bed reef of FIG. It is a perspective view of the fixing metal fitting for fixing the bottom connecting facility of FIG. 7 to a reef or the like. It is a perspective view which concerns on the modification of the fixing metal fitting of FIG.

Hereinafter, a method for creating a seaweed fishing ground according to an embodiment of the present invention will be described. In this method, a fishing ground is created through the cultivation of seaweed using the seaweed bed 1 shown in FIGS. 1 to 8. Seaweeds such as kelp, which are the targets of breeding, have conventionally been used as feed for herbivores such as sea urchins and abalone. However, in recent years, it has been pointed out that food shortages have continued due to the occurrence of shore-burning phenomena and the like, resulting in a significant decline in the landing of herbivores and deterioration in quality. Therefore, in the method of creating this seaweed fishing ground, the grown seaweed is used as a feed for herbivores while promoting the growth of the seaweed. For this reason, the seagrass bed reef 1 is a facility constructed by using both the following standing rope substrate 100 (first substrate in the present invention) and bottom connecting facility 200 (second substrate in the present invention). First, the standing rope substrate 100 will be described, and then the construction of a facility using both the standing rope substrate 100 and the bottom connecting facility 200 will be described.

The standing rope substrate 100 is attached to and installed on a natural product such as a reef on the seabed or an artificial installation such as a concrete block installed on the seabed (hereinafter referred to as a reef or the like). As shown in FIG. 1, the standing rope substrate 100 includes a thin rope 101 (first member in the present invention), a thick rope 102 (second member in the present invention), a float 103 (floating member in the present invention), and a fixing metal fitting 110. (First fixing bracket in the present invention) is provided. The portion composed of the thin rope 101 and the thick rope 102 corresponds to the first string-shaped member in the present invention. The thin rope 101 and the thick rope 102 are ropes made of synthetic fibers, respectively. One end of the thin rope 101 is fixed to the surface of a reef or the like by a fixing bracket 110. A float 103 is fixed to the other end of the thin rope 101. The float 103 is a member made of foamed plastic having a spindle shape. The float 103 is formed with a through hole extending so as to connect both ends in the elongated direction. The other end of the thin rope 101 is passed through the through hole, and a knot or the like for retaining is formed in the portion of the thin rope 101 near the opening of the through hole, so that the float 103 is formed at the other end of the thin rope 101. Is fixed. As a result, the standing rope substrate 100 is configured so that the thin rope 101 extends from the spindle-shaped tip of the float 103.

The thick rope 102 is a rope woven with a plurality of (for example, 2 to 3) synthetic fiber ropes, or a rope having a large diameter. As shown in FIG. 1, the thick rope 102 is combined with a portion in the middle of the thin rope 101. As a result, the vertical rope substrate 100 has a small diameter portion 100a which is a portion from one end fixed to the fixing metal fitting 110 to the end portion of the thick rope 102 and a large diameter portion 100b which is a portion provided with the thick rope 102. And are formed. In the large diameter portion 100b, which is thicker than the small diameter portion 100a, the false roots of seaweeds such as kelp are more likely to adhere more firmly. On the other hand, the small diameter portion 100a is a portion where herbivores, particularly sea urchins, do not easily crawl up, as will be described later. As shown in FIG. 2, for example, the thin rope 101 and the thick rope 102 are combined by passing the thin rope 101 through the stitches (between the woven ropes) of the thick rope 102. These are fixed by tying and adhering the stop thread 105 in a state of being combined with each other.

The fixing bracket 110 is used by being inserted into a reef or the like. The insertion direction is, for example, a direction parallel to the vertical direction, but may be a direction intersecting the vertical direction. As shown in FIGS. 3 and 4, the fixing bracket 110 is formed by bending one metal rod-shaped member. As a result, the resistance of the fixing bracket 110 to electrolytic corrosion is more likely to be ensured than in the case where the fixing bracket 110 is composed of a combination of a plurality of members. On the other hand, when a conventional anchor pin and eye nut are used instead of the fixing metal fitting 110, since these two members are usually made of dissimilar metals, corrosion is likely to proceed at the contact portion of the members. Become. The fixing bracket 110 is bent in the insertion direction from one end of the main body portion 111 (straight line portion in the present invention) extending linearly along a direction substantially orthogonal to the insertion direction into the reef or the like. It has an insertion portion 112 (first insertion portion in the present invention) and a loop portion 113 bent in a loop shape from the other end of the main body portion 111. The insertion portion 112 extends linearly along the insertion direction. The tip of the insertion portion 112 is formed to be sharp (a state in which the tip is cut off), and a surface 112a is formed along a direction oblique to the insertion direction.

The loop portion 113 is once curved from the other end of the main body portion 111 in the direction opposite to the insertion direction to form the curved portion 114, and is curved from the curved portion 114 in the insertion direction so as to intersect the main body portion 111. The insertion portion 115 (the second insertion portion in the present invention) is formed. A thin rope 101 is tied to the upper portion 114a (the connecting portion in the present invention) of the curved portion 114. As shown in FIG. 4, the tip of the insertion portion 115 is formed to be sharp (tapered), and a surface 115a is formed along a direction oblique to the insertion direction. The insertion portion 115 projects smaller than the insertion portion 112 in the insertion direction. With respect to the direction orthogonal to the insertion direction, the distance from the curved portion 114 to the insertion portion 115 is smaller than the distance from the curved portion 114 to the insertion portion 112. The fixing bracket 110 is fixed by inserting both the insertion portion 112 and the insertion portion 115 into a hole formed in a reef or the like.

The installation method of the standing rope substrate 100 is as follows. First, the thin rope 101 and the thick rope 102 are prepared. The thick rope 102 may be made by knitting a rope or may be attached with a rope having a large diameter. Then, the float 103 is fixed to the thin rope 101 at the preliminary preparation stage or the installation site, and the thick rope 102 is combined with the thin rope 101. At the installation location on the seabed, two holes corresponding to the insertion portion 112 and the insertion portion 115 of the fixing bracket 110 are formed in a reef or the like. Then, after inserting the insertion portion 112 and the insertion portion 115 of the fixing bracket 110 into the holes, a hammer is applied to the main body portion 111 of the fixing bracket 110 in the insertion direction. The fixing method of the fixing bracket 110 may be appropriately selected depending on the situation of the fixing place (rock bed or the like). For example, for clay rock, an adhesive for underwater may be used when the fixing force is expected to be insufficient when the clay rock is fixed by hitting. As a result, the insertion portion 112 and the insertion portion 115 are securely inserted into the holes. After fixing the fixing bracket 110 to the reef or the like in this way, the tip of the thin rope 101 is connected to the curved portion 114 of the fixing bracket 110. The fixing bracket 110 may be fixed to a reef or the like after the tip of the thin rope 101 is connected to the curved portion 114 in advance. The standing rope substrate 100 is arranged so that the upper part floats and floats on the sea surface as shown in FIG. 1, for example.

The specific composition of the standing rope substrate 100 may be appropriately adjusted at the site according to the target seaweed and the installation environment. The objects to be adjusted are, for example, the length of the thin rope 101, the number of float 103 and the thick rope 102 attached to the thin rope 101, and the fixed position. The standing rope substrates 100 ″ and 100 ″ shown in FIG. 1 are configuration examples different from those of the standing rope substrate 100. The standing rope substrate 100'is an example in which the whole is placed in a state of being submerged in the sea. The vertical rope substrate 100 ″ is an example of attaching two floats and two thick ropes 102 to a thin rope 101. In the vertical rope substrate 100 ″, the float 103, the thick rope 102, the float 103, and the thick rope 102 are attached to the thin rope 101 in this order from the tip of the thin rope 101. The configurations of the thin rope 101 and the thick rope 102 may be changed depending on the water depth and the wave environment. For example, it may be composed of only a thin rope. This is because the wave resistance is reduced and the material fatigue is reduced by the thin rope 101 alone in a fishing ground where the water depth is shallow.

An example of using the standing rope substrate 100 is as follows. This embodiment is mainly assumed to be applied to kelp as seaweed, but may be applied to other seaweeds such as Sargassum and Ecklonia cava. A natural seedling collection method is used for the growth of seaweed on the standing rope substrate 100. For example, zoospores flowing out from natural mother algae in kelp such as kelp are settled on the standing rope substrate 100. Therefore, the standing rope substrate 100 is installed in the outflow route of zoospores from the mother algae of seaweed. For example, the standing rope substrate 100 is arranged concentrically (or concentrically) with respect to the center C of the mother algae group around the mother algae group formed along the coast as shown in FIG. Specifically, a plurality of vertical rope substrates 100 are arranged along each of the elliptical rows E1 and E2 centered on C. In each of rows E1 and E2, as shown in FIG. 5, in consideration of the influence of the predominant coastal current, the number of per-length along the row should be larger on the downstream side of the predominant current than on the upstream side. Place the estradiol substrate 100. This is because zoospores flowing out of the mother algae are concentrated on the downstream side of the predominant flow. Further, the standing rope substrate 100 may be arranged so that the number per area of the fishing ground decreases as the distance from the mother algae group increases. The smaller the distance from the mother algae group to each standing rope substrate 100, the better, but it is preferably up to about several hundred meters. In this way, by installing a large number of standing rope substrates 100 on the downstream side of the center of the mother algae group as compared with the upstream side, zoospores efficiently settle on the standing rope substrate 100. In each standing rope substrate 100, as shown in FIG. 1, seaweeds grow large mainly in the large diameter portion 100b where false roots are easily fixed and developed.

According to the standing rope substrate 100 according to the present embodiment, seaweed is settled in the facility by installing it in the outflow route of spores from the mother algae. As described above, in an environment where a mother algae community exists in the vicinity of a fishing ground, it is not necessary to collect seedlings on the standing rope substrate 100 (and the bottom connecting facility 200 described later) before installation. Therefore, the process of introducing the facility to the installation location on the seabed is simple. Further, after the standing rope substrate 100 is installed, the substrate body (thin rope 101 and thick rope 102) is arranged by the float 103 so as to extend vertically from the fixing metal fitting 110 toward the sea surface in the sea. Therefore, spores floating in the sea can effectively settle on the substrate body.

In the case of a fishing ground where the mother algae community does not exist in the first year, it is advisable to transfer the substrate to supply the zoospores after collecting seedlings on the standing rope substrate 100 at the fishing ground where the mother algae community exists.

By the way, when the standing rope substrate 100 is installed in the area near the coast as described above, the influence of the waves on the facility becomes stronger. For example, as shown by the double-headed arrow W in FIG. 1, the upper part of the standing rope substrate 100 sways back and forth according to the propagation direction of the wave, and the entire standing rope substrate 100 also sways accordingly. In particular, the small diameter portion 100a, which is thinner than the large diameter portion 100b, tends to sway due to waves. Therefore, it is difficult for herbivores, especially sea urchins, to crawl up in the small diameter portion 100a, and it is difficult for the herbivores to reach the large diameter portion 100b above. Therefore, the feeding damage of the seaweed that has settled on the large diameter portion 100b by the herbivores is suppressed.

On the other hand, if the influence of the waves is too strong, the standing rope substrate 100 may be damaged by the waves. For example, the float 103 is swept within the length of the rope according to the waves. Then, when the float 103 is flushed until the rope becomes tense, the float 103 is submerged in water and passes through the peak of the waves. At this time, a tensile force from the vicinity of the sea surface is repeatedly applied to the rope. This may lead to breakage due to rope fatigue. On the other hand, in the present embodiment, the float 103 has a spindle shape, and the standing rope substrate 100 is configured so that the thin rope 101 extends from the tip of the spindle shape. Therefore, the float 103 is likely to be arranged so that the elongated direction of the float 103 flutters in the same direction as the flow due to the waves. When the elongated direction of the float 103 follows the propagation direction of the wave, the resistance of the float 103 to the wave becomes small. Therefore, the possibility that the standing rope substrate 100 is damaged or flows out due to the influence of waves is suppressed.

Further, as the vertical rope substrate 100 is pulled by the waves, a tensile force F in the generally upward omnidirectional direction acts on the upper portion 114a of the curved portion 114 to which the thin rope 101 is connected, as shown in FIG. To do. On the other hand, the fixing bracket 110 is supported by both the insertion portion 112 and the insertion portion 115 inserted into the reef or the like. Both the insertion portion 112 and the insertion portion 115 are separated from the upper portion 114a of the curved portion 114 in the left-right direction (direction orthogonal to the insertion direction) in FIG. Therefore, a tensile force that fluctuates in all directions as shown in FIG. 3 is applied to the curved portion 114, and this tensile force acts as a deformation stress on the main body portion 111. On the other hand, a bearing force downward (insertion direction) is generated in the insertion portion 115, and this bearing force becomes resistance to the tensile force and balances with the deformation due to the deformation stress, so that the entire fixing member 110 is deformed or damaged. Durability is maintained without slackening. Even if the insertion portion 115 comes out of the reef or the like, the insertion portion 112 inserted into the reef or the like deeper than the insertion portion 115 supports the fixing bracket 110.

Further, the thin rope 101 and the thick rope 102 are combined so that the thin rope 101 straddles both the small diameter portion 100a and the large diameter portion 100b. On the other hand, it is assumed that the small diameter portion 100a and the large diameter portion 100b are formed by firmly binding and connecting the ends of the thick string and the thin string. In this case, the strength of the vertical rope substrate 100 may be relatively weakened due to stress concentration or bending fatigue at the connecting portion of the boundary between the small diameter portion 100a and the large diameter portion 100b. In addition, there is a possibility that a difference in the swinging cycle may occur between the small diameter portion 100a and the large diameter portion 100b having different thicknesses due to waves. When the standing rope substrate 100 is pulled by a strong wave, the connecting portion is broken, and the standing rope substrate 100 may be damaged. On the other hand, in the present embodiment, since the thin rope 101 straddles both the small diameter portion 100a and the large diameter portion 100b, the strength is unlikely to be weakened at the boundary between the small diameter portion 100a and the large diameter portion 100b. Therefore, the breakage of the standing rope substrate 100 is suppressed.

Next, the method for creating the above-mentioned seaweed fishing ground will be described. As shown in FIG. 6, the bottom connecting facility 200 includes ropes 201a to 201c (second string-shaped member in the present invention) stretched along a direction connecting land and offshore (hereinafter, referred to as “land offshore direction”). Is a facility in which multiple lines are arranged in the direction orthogonal to the offshore direction. The ropes 201a to 201c are all made of synthetic fibers, and are adjusted to a thickness at which the false roots of seaweed can easily adhere. The rows of three ropes 201a to 201c are provided, for example, in a region on the coast having a side of about several tens of meters at approximately equal intervals in a direction orthogonal to the offshore direction. The standing rope substrate 100 is used by transferring a seaweed that has grown sufficiently to the extent that the seaweed that has settled by the above-mentioned natural seedling collection method can release spores from the seedling collection location to the installation area of the seaweed bed reef 1. The vertical rope substrate 100 is installed on the upstream side of the entire bottom connecting facility 200 with respect to the predominant coastal flow, and at or near the intermediate portion of the bottom connecting facility 200 with respect to the direction orthogonal to the offshore direction. At these two locations, a plurality of standing rope substrates 100 are arranged at substantially equal intervals along the offshore direction.

The bottom connecting facility 200 will be described in more detail. As shown in FIGS. 6 and 7, the ropes 201a to 201c are fixed to a reef or the like by using fixing brackets 110 and 210 so as to extend in the offshore direction. As shown in FIG. 7, the ropes 201a to 201c are stretched so as to substantially follow the unevenness of the reef or the like on the seabed. The fixing metal fitting 110 is the same as that used for the standing rope substrate 100. The fixing bracket 110 is used to fix both ends of the ropes 201a to 201c to a reef or the like on the seabed. The fixing brackets 210 (second fixing brackets in the present invention) are arranged in a row along the offshore direction as shown in FIGS. 6 and 7. As shown in FIG. 8, the fixing bracket 210 includes a vertical bar 211 inserted into a reef or the like, and a horizontal bar 212 (intersection portion in the present invention) fixed to the upper end of the vertical bar 211 so as to intersect with the vertical bar 211. The flat plate 213 fixed slightly above the lower end of the vertical rod 211, the four reinforcing rods 214 diagonally passed from the horizontal rod 212 to the flat plate 213 with respect to the vertical rod 211, and fixed to one end of the flat plate 213. It has a vertical bar 216. All of these members are made of metal and are fixed to each other by welding. The vertical bar 211 is formed in a straight line, and its lower end is sharply formed. A cylindrical rod 215 made of solid cylindrical material is fixed to the upper end surface of the vertical rod 211. The cylindrical rods 215 project from the upper end surface of the vertical rods 211 to both sides of the vertical rods 211. A rope 201b is connected to the upper end portion 211x of the vertical bar 211. The cylindrical rod 215 regulates the rope 201b tied to the vertical rod 211 so as not to fall out of the vertical rod 211. The vertical bar 216 is formed in a straight line, and the lower end thereof is sharply formed. The portions of the vertical bars 211 and 216 below the flat plate 213 form insertion portions 211a and 216a (third insertion portion and fourth insertion portion in the present invention) to be inserted into a reef or the like. In this way, since the two insertion portions 211a and 216a are inserted into the reef or the like, the fixing metal fitting 210 is suppressed from rotating around the axis along the insertion direction. In the vertical bar 211, the portion above the insertion portion 211a (the main body portion in the present invention) is longer than the insertion portion 211a in the vertical direction.

The horizontal bar 212 is formed in a straight line so as to project in a direction orthogonal to the vertical bar 211 toward both sides of the vertical bar 211. Cylindrical bars 215 are fixed to each of the left and right end faces of the horizontal bar 212. Rope 201a and 201c are connected to both ends 212x of the horizontal bar 212 in the direction orthogonal to the vertical bar 211. The cylindrical rod 215 projects vertically from the left and right end faces of the horizontal rod 212. The cylindrical rod 215 regulates the ropes 201a and 201c tied to the horizontal rod 212 so as not to fall out of the horizontal rod 212. The flat plate 213 is formed in a straight line so as to project in a direction orthogonal to the vertical bar 211 toward both sides of the vertical bar 211. The flat plate 213 is in contact with the surface of a reef or the like. The upper ends of two of the four reinforcing rods 214 are fixed at positions slightly closer to the center than one end of the horizontal rod 212, and the lower ends are fixed to both ends of the flat plate 213. The upper ends of the remaining two rods are fixed at positions slightly closer to the center than the other end of the horizontal bar 212, and the lower ends are fixed to both ends of the flat plate 213.

The installation method of the bottom connecting facility 200 is as follows. As an example, a case where ropes 201a to 201c are installed from the offshore side to the land side will be described. First, the fixing bracket 110 is installed on both the offshore side and the land side, and the work boat is fixed to or moved between them. As a result, the outline in the offshore direction is determined, the movement or fixation of the work vessel can be set at any place, and the work time associated with the movement / fixation can be shortened. Next, for example, the ropes 201a to 201c are extended from the first fixed position on the offshore side to the second fixed position closer to the land side by a predetermined distance. Then, the ropes 201a to 201c are fixed at the second fixing position by using the fixing bracket 210. Specifically, holes corresponding to the insertion portions 211a and 216a of the fixing bracket 210 are formed in the reef or the like. Then, after inserting the insertion portions 211a and 216a of the fixing bracket 210 into the holes from above, a hammer is applied to the upper end portion of the fixing bracket 210 from above. As a result, the insertion portions 211a and 216a are securely inserted into the holes until the flat plate 213 comes into contact with the reef or the like. Use underwater adhesives (including resin molds) to increase the fixing strength. Further, the orientation of the fixing bracket 210 is adjusted so that the horizontal bar 212 intersects the land-offshore direction. Next, the ropes 201a to 201c are extended from the second fixed position to the third fixed position which is closer to the land side by a predetermined distance. Then, at the third fixing position, the ropes 201a to 201c are fixed by using the fixing metal fitting 210 as in the second fixing position. By repeating this, the ropes 201a to 201c are stretched along the offshore direction using the fixing bracket 210. At the fixed position on the most land side in the planned installation area of the facility, after fixing the fixing bracket 110 to the reef or the like as described above, one end of the ropes 201a to 201c is connected to the upper part 114a of the curved portion 114. At each fixed position, it is preferable that the ropes 201a to 201c are stretched so that the ropes 201a to 201c do not loosen from the adjacent fixed positions.

The method of creating a seaweed fishing ground by growing seaweed using seaweed bed 1 is as follows. When spores are released from the mother algae that have settled on the vertical rope substrate 100, the spores flow out mainly to the bottom connecting facility 200 on the downstream side by the coastal flow, and settle on the ropes 201a to 201c of the bottom connecting facility 200. To do. When seaweed grows on the ropes 201a to 201c, the seaweed gradually grows toward the surface of the reef or the like on the seabed. In this way, three ropes are provided for each row of the fixing brackets 210 arranged along the offshore direction, and seaweed grows on these three ropes. Therefore, it is possible to grow more seaweed as compared with the case where only one rope is fixed to the fixing metal fittings 210 arranged in a row.

Since the ropes 201a to 201c are connected to the upper portion of the fixing bracket 210 (the upper end portion 211x of the vertical rod 211 and the both end portions 212x of the horizontal rod 212), they are separated above the surface of the reef or the like on the seabed. Therefore, the seaweed does not reach the surface of the reef or the like for a while after the start of growth of the seaweed. Therefore, it is less likely to be exposed to the feeding damage of herbivores living on reefs and the like. Therefore, the growth of seaweed due to feeding damage is less likely to be inhibited in the initial stage of growth. On the other hand, as the growth progresses and the seaweed reaches the surface of the reef or the like as shown in FIG. 7, it becomes a target for feeding by herbivores. However, under high wave conditions such as the time of storm, the "striking effect" of the seaweed hitting the herbivore becomes severe due to the swaying movement of the seaweed that has settled on the ropes 201a to 201c and hung down. In such a case, the herbivore will evacuate to a place where it will not be hit by the seaweed, so the seaweed will be temporarily stopped feeding, and if this condition continues for several days, the seaweed will grow again (especially kelp is 5 to 8 cm / day). Then the food supply increases.

Further, when the bottom connecting facility 200 is installed in a place where the surface is uneven like a reef, the distance from the ropes 201a to 201c to the upper surface of the reef varies. Therefore, the seaweed grown on the ropes 201a to 201c may hang down on the surface of the reef or may not reach the surface of the reef depending on the place where it has settled. Therefore, it is possible to feed some of the seaweeds to the herbivores while avoiding the situation where all the seaweeds settled on the ropes 201a to 201c are exposed to the feeding damage of the herbivores. As described above, according to the method of growing seaweed using the bottom connecting facility 200, it is easy to balance the suppression of feeding damage by the herbivores and the provision of feed to the herbivores. As a result, the method for creating a seaweed fishing ground using the seaweed bed 1 makes it easy to use the grown seaweed as feed for herbivores while promoting the growth of the seaweed.

The ropes 201a to 201c are all installed along the offshore direction. Since the offshore direction is generally the direction of wave approach to the coastline, for example, compared to the case where these ropes are installed in the coastline direction orthogonal to the offshore direction, they are less susceptible to waves and the facility itself. Weather resistance and durability are improved within the practical range.

According to the method for creating a seaweed fishing ground according to the present embodiment described above, first, spores from natural mother algae are settled on the standing rope substrate 100. The standing rope substrate 100 can be installed by a simple method of fixing the substrate main body (thin rope 101 and thick rope 102) to which the float 103 is fixed to a reef or the like on the seabed with a fixing metal fitting 110. It also places the substrate body in the path of spores from natural mother algae flowing through the sea. Therefore, it is easy to place the standing rope substrate 100 at an appropriate position where spores from natural mother algae can be grown. Further, the standing rope substrate 100 is arranged so that the substrate main body extends from the fixing metal fitting 110 toward the sea surface. Since the first string-shaped member arranged in this way sways under the influence of waves, the seaweed that has settled on the substrate body is less likely to be damaged by herbivores living on the seabed. Therefore, it is easy to surely protect and grow seaweed to the stage where spores can be released in the standing rope substrate 100.

Next, the seaweed that has grown on the standing rope substrate 100 is used as the mother algae, and the spores from the mother algae are further settled in the bottom connecting facility 200. The standing rope substrate 100 may be used as it is at the position where the seedlings were collected from the natural mother algae, or may be moved to a place (new fishing ground or the like) separated from the seedlings. As described above, the vertical rope substrate 100 has a simple structure in which one end of the substrate body is fixed by the fixing metal fitting 110. Therefore, it is easy to move the substrate body on which seaweed has settled to another place and use it. The bottom connecting facility 200 has a simple configuration in which the ropes 201a to 201c are installed on a reef or the like by a fixing metal fitting 210 so as to extend in a direction intersecting the vertical direction. Therefore, it is easy to expand the scale of the facility by a simple method of extending the ropes 201a to 201c. Further, as described above, the ropes 201a to 201c are tied to the upper part of the fixing metal fitting 210, and are thus arranged above the reef or the like. Therefore, the seaweed does not reach the natural product or the artificial installation during the period until the seaweed grows and extends on the ropes 201a to 201c. In addition, since the ropes 201a to 201c extend in the water offshore, the flow of water around the substrate derived from the waves constantly suppresses the feeding behavior by the herbivores and grows on the ropes 201a to 201c. Upset seaweed. Due to this agitation, seaweed beats herbivores and suppresses their feeding behavior. Therefore, feeding damage caused by herbivores such as sea urchins living on the seabed crawling on the substrate and feeding on seaweed is greatly suppressed. Then, when seaweed grows, a part of it reaches the reefs on the seabed and becomes a target for feeding of herbivores in a state where the amount of feed is increased.

As described above, in the present embodiment, it is possible to prevent the settled seaweed from being damaged by the herbivore while appropriately growing the spores released by the natural mother algae on the standing rope substrate 100. As a result, spores supplied from a limited number of natural mother algae can be protected and grown, and seaweed can be reliably grown up to the stage of releasing spores. In addition, spores from the mother algae grown on the standing rope substrate 100 are settled in the bottom connecting facility 200. The standing rope substrate 100 can also be moved to a place where the fishing ground is desired to be created and expanded. In the bottom connecting facility 200, feeding damage by herbivores can be suppressed until the seaweed grows sufficiently. Further, since the bottom connecting facility 200 can provide a new epiphytic substrate by extending the ropes 201a to 201c, the scale can be easily expanded. As a result, in the present embodiment, seaweed of a sufficient scale is produced while appropriately controlling the feeding damage in the fishing ground where the herbivore inhabits and continuously protecting and growing the seaweed for a long period of time. Fishing grounds can be created, and the fishing grounds can be used as feeding grounds for herbivores. In addition, large-scale facilities such as those in the prior art are likely to be unnecessary, and maintenance and management are facilitated.

Hereinafter, the background of the present inventor's creation of the present invention will be described. The following description is not intended to limit the technical scope of the present invention. First, the fishing grounds are as follows. The fishing ground is a place where seaweed grows on the bottom sediment of rock reefs and bedrock, but since sea urchins and other herbivores inhabit at high density depending on the season, many seaweeds are damaged in the early stages of growth and seaweed beds It is not formed and the shore burning phenomenon continues. As a breakthrough measure, extermination / removal that artificially reduces the feeding pressure of herbivores is carried out by diving, basket fishing gear, and onboard fishing. However, as a guideline for reducing the feeding pressure, a sea urchin weight of 200 g or less per square meter (3 to 4 individuals or less per square meter in terms of the number of sea urchins) is required, and it takes a lot of manpower and cost to achieve this standard. There has been a demand for an inexpensive and efficient method for removing sea urchins. In the present invention, in a fishing field where herbivores such as sea urchins inhabit at a high density, seaweeds are grown in the middle layer of the fishing field for a certain period of time while reducing the feeding pressure without requiring removal of these animals and grow large (feed). A bottom-connecting facility was realized as a method of feeding seaweed to herbivores after maximizing seaweed) and forming a seaweed fishing ground.

Secondly, the seedling collection is as follows. Existence of natural mother algae community (relocated if not present) → Ascospore formation and zoospore release in mother algae community → Spores released at short distances are transported and dispersed in a high density → This short distance Epiphytic matrix is installed in a high-density place → zoospores can settle in a short time at short distances and healthy seedlings (energetic seedlings) can be collected → Short-distance seedlings are surely natural harvested at fishing grounds It became a method of seedlings and realized this with a standing rope substrate → Epiphytic seedlings are healthy seedlings and have good initial survival and growth → After being culled, they tend to grow in size and remain on the substrate for a long time → Mother algae community formation on the substrate → It becomes a group of mother algae that can be relocated.

Thirdly, the facilities are as follows. A facility that can overwinter in a harsh environment in shallow water → The facility determines the balance of fixed, floating and epiphytic substrates from tests → Stand rope protects and grows from mother algae in fishing grounds to natural seedlings, relocation, and epiphytic seaweed To do. → The bottom connecting facility can overwinter with a facility that is fixed at two points → Maximum use of coastal wave characteristics → Development of fixing brackets → Minimum wave resistance by offshore staking and use near the seabed where the flow velocity is slow → With the common wisdom of horizontal facilities Remove the float that was there → Tension tension of a thin rope (minimizing the cross-sectional area where wave resistance is applied) with a short extension distance of 3 to 5 m → Suppress the movement of up, down, left and right and reduce material fatigue → The facility is in a state of overwintering and maintenance (Minimum condition to obtain kelp. This is the biggest challenge and there were few successful cases of coastal facilities) → Seaweed grown and extended on the substrate is used as food for predators (without human intervention) It functions as a fishing ground where protected and raised seaweeds are fed.

<Modification example>
The above is a description of a preferred embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and various changes can be made as long as it is described in the means for solving the problem. It is possible.

For example, in the above-described embodiment, it is assumed that the seagrass bed reef 1 is installed on a natural product such as a reef. However, the standing rope substrate 100 and the bottom connecting facility 200 may be installed in artificial installations such as seagrass beds, fish reefs, marine structures, and stone-throwing fishing grounds that have been constructed on the seabed in the past. Further, as a natural product other than the reef, the standing rope substrate 100 and the bottom connecting facility 200 may be installed on the sand.

Further, instead of the fixing metal fitting 210 in the above-described embodiment, the fixing metal fitting 310 shown in FIG. 9 may be used. The fixing bracket 310 is used to fix only one rope 201a. The fixing bracket 310 has vertical bars 311 and 312 separated from each other in the direction in which the rope 201a is stretched, and horizontal bars 313 and 314 connecting the vertical bars 311 and the vertical bars 312. These members are fixed by being welded to each other. The horizontal bar 313 and the horizontal bar 314 are separated from each other in the vertical direction. The rope 201a is connected to the portion directly below the horizontal bar 313 at the vertical bars 311 and 312. The rope 201a may be connected to a portion of the vertical bars 311 and 312 between the horizontal bars 313 and the horizontal bars 314 other than directly below the horizontal bars 314. The portions of the vertical bars 311 and 312 below the horizontal bars form insertion portions 311a and 312a (third insertion portion and fourth insertion portion in the present invention) to be inserted into a reef or the like. In this way, since the two insertion portions 311a and 312a are inserted into the reef or the like, the fixing metal fitting 310 is suppressed from rotating around the axis along the insertion direction.

In the above-described embodiment, both the standing rope substrate 100 and the bottom connecting facility 200 are used as the seaweed bed reef 1. However, from a viewpoint different from the present invention, the standing rope substrate 100 may be used alone. In this case, it may be used as (1) a facility for natural seedling collection, (2) a protection and breeding facility after natural seedling collection, or (3) a seed field (nuclear seaweed bed) by relocation to another fishing ground. obtain. In addition, it is possible to further expand the habitat of the seaweed by adding the standing rope substrate 100 to the grown seaweed.

1 Seaweed bed reef 100a Small diameter part 100b Large diameter part 100 Standing rope Substrate 101 Thin rope 102 Thick rope 103 Float 110 Fixing bracket 111 Main body 112, 115 Insertion part 114 Curved part 200 Bottom connecting facility 201a to 201c Rope 210 Fixing bracket 211a Insertion part 211 Vertical bar 212 Horizontal bar

Claims (9)

It is a method of creating a seaweed fishing ground using the first substrate and the second substrate in a fishing ground where herbivores inhabit.
The first substrate is a first string-shaped member whose one end is fixed to a natural product or artificially installed object on the seabed by a first fixing bracket, and a floating member fixed to the other end of the first string-shaped member. Have and
The second substrate has a second string-like member that is fixed to a natural product or an artificial installation on the seabed by a second fixing bracket.
The first string-like member is arranged in the path through which spores from natural mother algae flow in the sea, and the buoyancy of the floating member causes the first string-like member to extend from one end toward the sea surface. A step of installing the first substrate and allowing spores from the mother algae to grow on the first string-like member.
A step of growing seaweed in the first string-shaped member while suppressing feeding damage by the herbivore by swaying the first string-shaped member due to the influence of waves.
The second string-like member is placed in the path through which spores from the mother algae that have settled on the first substrate flow, and the second string-like member is located offshore above a natural or artificial installation on the seabed. A step of arranging the second substrate so as to extend in the direction and allowing spores from the mother algae to grow on the second string-like member.
It is provided with a step of feeding the herbivore by allowing at least a part of the seaweed grown in the second string-shaped member to reach the upper surface of a natural product or an artificial installation on the seabed.
The first string-shaped member has a small diameter portion and a large diameter portion which are portions having different thicknesses from each other.
A method for creating a seaweed fishing ground , wherein the small diameter portion is located above the first fixing bracket in the first string-shaped member. It is a method of creating a seaweed fishing ground using the first substrate and the second substrate in a fishing ground where herbivores inhabit.
The first substrate is a first string-shaped member whose one end is fixed to a natural product or artificially installed object on the seabed by a first fixing bracket, and a floating member fixed to the other end of the first string-shaped member. Have and
The second substrate has a second string-like member that is fixed to a natural product or an artificial installation on the seabed by a second fixing bracket.
The first string-like member is arranged in the path through which spores from natural mother algae flow in the sea, and the buoyancy of the floating member causes the first string-like member to extend from one end toward the sea surface. A step of installing the first substrate and allowing spores from the mother algae to grow on the first string-like member.
A step of growing seaweed in the first string-shaped member while suppressing feeding damage by the herbivore by swaying the first string-shaped member due to the influence of waves.
The second string-like member is placed in the path through which spores from the mother algae that have settled on the first substrate flow, and the second string-like member is located offshore above a natural or artificial installation on the seabed. A step of arranging the second substrate so as to extend in the direction and allowing spores from the mother alga to grow on the second string-like member
It is provided with a step of feeding the herbivore by allowing at least a part of the seaweed grown in the second string-shaped member to reach the upper surface of a natural product or an artificial installation on the seabed.
When to settlement of the spores from the natural mother algae, Construction method seaweed fisheries characterized that you set up the number of the first substrate on the downstream side than the upstream side with respect to coastal prevailing flow. It is a method of creating a seaweed fishing ground using the first substrate and the second substrate in a fishing ground where herbivores inhabit.
The first substrate is a first string-shaped member whose one end is fixed to a natural product or artificially installed object on the seabed by a first fixing bracket, and a floating member fixed to the other end of the first string-shaped member. Have and
The second substrate has a second string-like member that is fixed to a natural product or an artificial installation on the seabed by a second fixing bracket.
The first string-like member is arranged in the path through which spores from natural mother algae flow in the sea, and the buoyancy of the floating member causes the first string-like member to extend from one end toward the sea surface. A step of installing the first substrate and allowing spores from the mother algae to grow on the first string-like member.
A step of growing seaweed in the first string-shaped member while suppressing feeding damage by the herbivore by swaying the first string-shaped member due to the influence of waves.
The second string-like member is placed in the path through which spores from the mother algae that have settled on the first substrate flow, and the second string-like member is located offshore above a natural or artificial installation on the seabed. A step of arranging the second substrate so as to extend in the direction and allowing spores from the mother algae to grow on the second string-like member.
It is provided with a step of feeding the herbivore by allowing at least a part of the seaweed grown in the second string-shaped member to reach the upper surface of a natural product or an artificial installation on the seabed.
The second fixing bracket has a third insertion portion to be inserted into a hole formed on the upper surface of a natural product or an artificial installation on the seabed, and a main body portion which is a portion above the third insertion portion.
A plurality of the second fixing brackets are arranged in a row in the land-offshore direction in a plan view, and the second string-shaped member is fixed to the main body portion of each of the plurality of second fixing brackets. How to create a seaweed fishing ground. The seaweed fishing ground according to any one of claims 1 to 3, wherein the floating member has a spindle shape, and the first string-shaped member extends from one end of the spindle shape. Creation method. The first string-shaped member is combined with the string-shaped first member extending across both the small-diameter portion and the large-diameter portion and the first member along the first member. The method for creating a seaweed fishing ground according to claim 1 , wherein the seaweed fishing ground is provided with a string-shaped second member forming a large diameter portion. The first fixing bracket is inserted in one direction into a connecting portion to which one end of the first string-shaped member is attached, and a hole formed in the natural product or the artificial installation object, and a second insertion portion and a second. It has an insertion part and
5. A aspect of claim 5 , wherein the distance between the first insertion portion and the connection portion is larger than the distance between the second insertion portion and the connection portion in a direction orthogonal to the one direction. The described method for creating a seaweed fishing ground. The first fixing bracket has one rod-shaped member, and the first fixing bracket has one rod-shaped member.
One end of the rod-shaped member is bent in one direction to form the first insertion portion.
The other end of the rod-shaped member forms a curved portion curved in a direction opposite to the one direction as the connecting portion, and intersects the straight portion connecting the curved portion and the one end portion. The seaweed fishing ground according to claim 6 , wherein the second insertion portion is formed so as to project from the curved portion in one direction by being bent in one direction. Creation method. The second fixing bracket has an intersection that intersects with the main body portion.
The seaweed fishing ground according to claim 3 , wherein a plurality of the second string-shaped members are fixed to the intersections of the second fixing brackets so as to be separated from each other in the horizontal direction. Creation method. A fourth insertion portion to be inserted into a hole formed on the upper surface of a natural product or an artificial installation on the seabed is provided so as to be separated from the third insertion portion in a direction intersecting the extending direction of the main body portion. The method for creating a seaweed fishing ground according to claim 3 or 8 , characterized in that.

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