JP3232772U - Algae farming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for effectively preventing feeding damage of cultured algae by algae-eating fish in algae cultivation. SOLUTION: (a) at least one algae holding member, and (b) a supporting member supporting the at least one algae holding member so that the at least one algae holding member is arranged at or near the water surface 8 in a farm. , (C) A feeding damage prevention net 7 for preventing algae feeding damage by algae-eating fish in the farm, and the feeding damage prevention net covers at least one algae holding member from below in the farm. The feeding damage prevention net and the algae holding member are arranged apart from each other so that the algae growing on the algae holding member are not damaged by the algae-eating fish, and the feeding damage prevention net is 5.5 cm to 19 cm. An algae cultivation system consisting of a mesh with a mesh length. [Selection diagram] Fig. 2

Description

The present invention relates to an algae aquaculture system and aquaculture method.

Examples of fish that feed on algae include omnivorous black sea bream, algae-eating brassy chub, largescale blackfish, and spinefish. In recent years, the number of black sea bream, large scale blackfish, and spinefish has increased rapidly in seaweed farms such as Tokyo Bay, and the feeding damage caused by these fish has become enormous in seaweed farming.

As a means for preventing the feeding damage of cultured algae by such fish, for example, a seaweed aquaculture tool (aquaculture system) 200 as shown in FIGS. 7 (a) and 7 (b) is known, and such aquaculture The ingredients are mainly used in the relatively deep waters of the Seto Inland Sea.

FIG. 1 shows the aquaculture tool of the first embodiment of the present invention viewed from above, but the conventional aquaculture tool 200 shown in FIGS. 7 (a) and 7 (b) is also shown in FIG. 1 when viewed from above. It has the form shown. Assuming that the aquaculture tool shown in FIG. 1 is the conventional aquaculture tool 200, the structure in which the portion indicated by reference numeral A in FIG. 1 is viewed in the lateral direction in water is shown in FIG. 7 (a). The structure of the portion shown by B as viewed from the lateral direction in water is shown in FIG. 7 (b).

In FIGS. 7A and 7B, the plurality of algae holding members (Nori net) 6 are supported by the buoyant body 2, the rope 4, and the anchor ropes 3b and 3c fixed to the seabed 15, so that the sea surface 8 It is located in the vicinity of. In order to prevent the invasion of fish that eat the seaweed that grows on the algae holding member 6, the feeding damage prevention net 9 is hung from the rope 4 toward the seabed 15, but it has not reached the seabed 15. , The aquaculture tool 200 is in an open state near the seabed 15.

JP 2016-77206

In the algae aquaculture system 200 as shown in FIGS. 7A and 7B, the algae-eating fish 18 is wary of the existence of the feeding damage prevention net 9 at the time when the algae aquaculture system 200 is installed. Therefore, it does not invade the inner region of the feeding damage prevention net 9. Therefore, the seaweed growing on the algae holding member 6 is not damaged. However, after a certain period of time has passed from the time when the algae culture system 200 was installed, the algae-eating fish 18 invaded the inside of the feeding damage prevention net 9 from the open area near the seabed 15 and settled on the algae holding member (nori net) 6. Learn to be able to prey on seaweed. Due to such a phenomenon, there is a problem that the feeding damage of the algae to be cultivated cannot be effectively prevented.

In addition, in recent years, among the algae-eating fish that can prey on the above-mentioned algae, the number of black sea bream, largescale blackfish, aigo, etc. has increased rapidly in the coastal waters of Japan in recent years, as shown in FIG. There is a problem that the algae farming system cannot sufficiently prevent the feeding damage caused by these algae-eating fish.

The above-mentioned algae-eating fish not only damage the algae in the cultivation of algae, but also damage the algae that live in the seagrass beds along the coast of Japan. .. Patent Document 1 discloses a nutrient supply system for algae as a means for recovering the feeding damage of such a seaweed bed. Patent Document 1 discloses, as an embodiment of the system, a configuration in which a water-permeable net is arranged under the algae holding member and the nutrient feeder in order to prevent the algae from being eaten by the algae-eating fish. (Fig. 1 of the same document, etc.). However, although it is described that a water-permeable net is arranged in order to prevent algae from being damaged by algae-eating fish, the nutrient supply system disclosed in Patent Document 1 is based on the algae field as a natural environment. It is characterized by using powdery granules containing reaction products of calcium silicate-based materials and phosphorus as a means of recovering from feeding damage, and is due to algae-eating fish whose algae population has increased rapidly in recent years in algae aquaculture. No disclosure or suggestion has been made of specific configurations or means for effectively preventing feeding damage to cultured algae and improving the production of cultured algae.

In order to solve the above problems, the following algae farming system is provided according to the first aspect of the present invention.

[1] (a) At least one algae holding member and
(B) A support member that supports the algae holding member so that at least one algae holding member is arranged on or near the water surface in the farm.
(C) A feeding damage prevention net that prevents algae from being eaten by algae-eating fish at the above farms,
With
The feeding damage prevention net is arranged so as to cover at least one algae holding member from below in the farm.
The feeding damage prevention net and the algae holding member are arranged apart from each other so that the algae growing on the algae holding member are not damaged by the algae-eating fish.
The feeding damage prevention net is composed of a mesh having a mesh length of 5.5 cm to 19 cm.
Algae farming system.

[2] The algae farming system according to [1], wherein the feeding damage prevention net has a property of settling when the feeding damage prevention net is floated alone on the water surface in the farm.
[3] The algae farming system according to [1] or [2], wherein the feeding damage prevention net is composed of a net having a mesh length of 7 cm to 16 cm.
[4] The algae farming system according to any one of [1] to [3], wherein the feeding damage prevention net is made of a material having a specific density larger than the specific density of water constituting the farm.

[5] The algae farming system according to any one of [1] to [4], wherein the feeding damage prevention net is made of a polymer fiber having a specific gravity of 1.1 or more.
[6] The feeding damage prevention net is made of any one of [1] to [5], which is composed of at least one fiber selected from the group consisting of nylon fiber, vinylon fiber, polyester fiber, and fluorocarbon fiber. The described algae cultivation system.

[7] The algae farming according to any one of [1] to [6], wherein the feeding damage prevention net has a property of settling when floating on the water surface in a farm by being provided with a weight or a sinker cord. system.
[8] The algae farming system according to any one of [1] to [7], further comprising at least one reinforcing net suspended from the support member in a substantially water bottom direction.

[9] The support member forms a plurality of aquaculture plots in the horizontal direction on the water, and each of the plurality of aquaculture plots is a substantially quadrilateral.
The at least one algae retention member is installed in at least one of the aquaculture plots.
The at least one reinforcing net includes two or more reinforcing nets.
The two or more reinforcing nets are suspended from the support member in the substantially water flow direction so as to face the water flow direction in water, and are substantially in the water flow direction with respect to at least one algae holding member located in the aquaculture section. The algae farming system according to any one of [1] to [8], which is arranged so as to be located on the upstream side.

[10] A method for producing algae, which comprises culturing algae using the algae culturing system according to any one of [1] to [9].
[11] The production method according to [10], wherein the algae are seaweeds.

[12] A method for cultivating algae, which comprises culturing algae using the algae cultivation system according to any one of [1] to [9].
[13] The cultivation method according to [12], wherein the algae are seaweeds.

[14] A kit for construction of the algae farming system according to any one of [1] to [9], which comprises the following elements:
An instruction that describes (i) a net that functions as the feeding damage prevention net; and (ii) a method for constructing the algae farming system and / or a method for producing or cultivating algae using the algae farming system.

Further, embodiments or modifications that can be taken in each of the above aspects of the present invention are exemplified below.

According to the present invention, it is possible to sufficiently prevent the algae from being damaged by the algae-eating fish without inhibiting the growth of the algae to be cultivated. In addition, according to the present invention, by adopting a feeding damage prevention net having a specific mesh length, small fish such as sardines and fish including relatively large algae-eating fish can be caught in the feeding damage prevention net. The algae farming system according to the present invention is easy to handle without the need to remove the fish from the feeding damage prevention net because the number of the algae is small or the number of the fish is small. Further, according to the present invention, as described below, since the configuration is adopted in which the lower part of the algae holding member is simply covered with a predetermined feeding damage prevention net, the work of constructing, maintaining, disassembling, etc. of the algae cultivation system is easy. In this respect as well, the algae cultivation system according to the present invention is excellent in handleability. Furthermore, in the algae farming system according to some embodiments of the present invention, since the feeding damage prevention net has a property of settling, the water environment of the farm due to unseasonable weather, water flow, sudden change of tidal current, etc. Even if the water is disturbed (for example, deterioration due to strong wind, heavy rain, fast current, etc.), the feeding damage prevention net will not be separated from the algae farming system. Therefore, the algae farming system according to the present invention is strong and has excellent durability.

It is a schematic diagram which looked at the algae culture system which concerns on Embodiment 1 of this invention from the top. FIG. 2A is a schematic view showing a portion A in FIG. 1 from the side surface. FIG. 2B is a schematic view showing a portion B in FIG. 1 from the side surface. It is a schematic diagram explaining the modification which concerns on Embodiment 1 of this invention. It is a schematic diagram which looked at the algae culture system which concerns on Embodiment 2 of this invention from the top. FIG. 5A is a schematic view showing a portion A in FIG. 4 from the side surface. FIG. 5B is a schematic view showing a portion B in FIG. 4 from the side surface. It is a figure for demonstrating the mesh length in this invention. It is a schematic diagram which shows the conventional algae culture system.

<Explanation of terms>
In the present invention, the "aquaculture farm" is a place where the algae farming system according to the present invention is installed and algae are cultivated using the algae farming system. Needless to say, the farm in the present invention has a water environment in which algae can grow. Examples of the aquaculture farm in the present invention include those using the water environment (rivers, lakes, swamps, seas, etc.) existing in the natural world. In a water environment in which fish that eat algae inhabit, if algae are cultivated using the algae cultivation system according to the present invention, it is possible to reduce or prevent feeding damage by fish.

In the present invention, "water surface or its vicinity" means a position with respect to the water surface in the water environment of the farm, and specifically, when the algae farming system according to the present invention is arranged in the farm. Refers to the position where the algae holding member is placed in the above water environment. The more specific position where the algae holding member is arranged may be appropriately determined based on the water surface in consideration of a suitable position for the algae to be cultivated, a position where the work is facilitated, and the like, and is particularly limited. It's not a thing. For example, since it is an algae, the algae-retaining member needs to be present in the water for a certain period of time, but the algae-retaining member is above the water surface because the water level changes due to a change in the tide level or the like. May be located. Regarding the cultivation of seaweed, it is said that it is preferable that the seaweed cultivation net, which is a member for holding algae, can be immersed in the sea and exposed to the sea due to the ebb and flow of the tide. .. It can absorb nutrients sufficiently while immersed in the sea, and shine enough sunlight on the seaweed while it is exposed to the sea to promote photosynthesis, and it is possible to produce high-quality seaweed with an increased madder color. .. It is also said to have the effect of preventing the adhesion of competing organisms such as diatoms. Aiming at such an effect, the algae holding member is arranged at a position on or near the water surface so that the time of being immersed in the sea and the time of being exposed to the sea can be set due to the ebb and flow of the tide. The algae holding member can be fixed to the support. In the present invention, the “water surface or its vicinity” includes, for example, a range of ± 1.5 m, ± 1 m, ± 50 cm, ± 30 cm, ± 20 cm, etc. from the water surface level.

In the present invention, the "algae" refers to "algae" to be cultivated, and the type thereof is not particularly limited. The algae in the present invention may be freshwater algae or marine algae. In general, it is marine algae that are more prominently damaged by fish. Therefore, in the present invention, the algae are preferably marine algae. Examples of marine algae include wakame seaweed, seaweed (black seaweed, green laver, etc.), kelp, hijiki seaweed, Ecklonia cava, mozuku seaweed, and tengusa.

In the present invention, the "algae-eating fish" means a fish that can prey on algae, and is not particularly limited. When the algae to be cultivated are marine algae, examples of fish that damage the algae include black sea bream, brassy chub, largescale blackfish, Aigo, Budai, Nizadai, black scraper, and stephanolepis crab. Especially in the cultivation of seaweed, the feeding damage of these fish has become remarkable in recent years. In the present invention, the "algal-eating fish" is not only algae-eating fish that normally prefers to prey on algae (for example, Isuzu, Medina, Aigo, Budai, Nizadai, Black scraper, Stephanolepis crab), but also isomes and gokais. The concept includes fish that prefer to prey on animals such as shellfish, shellfish, and small fish, and fish that can also prey on algae (for example, miscellaneous fish such as black scraper).

In the present invention, the term "algae farming system" is used not only for algae farming tools or algae farming equipment constructed or manufactured by assembling necessary components or elements in a farm, but also for their configurations before they are installed in the farm. It is a concept that also includes algae farming tools or algae farming equipment that are constructed or manufactured by assembling members or elements.

In the present invention, the term "kit for use in constructing an algae farming system" means a combination of components, members, materials and the like necessary for constructing the algae farming system. Two or more of the components and the like included in the combination may be connected so as to be able to constitute the algae farming system in the kit, but they do not have to be connected, and the algae farming system is constructed. It suffices to connect when doing.

<Algae farming system>
Hereinafter, embodiments 1 and 2 will be described with reference to the drawings regarding the algae farming system of the present invention. It should be noted that the embodiments shown below are merely examples for preferably explaining the present invention, and do not limit the present invention in any way.

[Embodiment 1]
FIG. 1 is a top view schematically showing the algae farming system 10 according to the first embodiment. Further, FIG. 2A is a view of the portion A in FIG. 1 viewed from the lateral direction, and FIG. 2B is a view of the portion B in FIG. 1 viewed from the lateral direction. Note that FIGS. 1 and 2 (a) and 2 (b) show an algae farming system in a state of being arranged in a farm. The algae farming system 10 according to the present embodiment is a so-called floating algae farming system. The configuration will be described below.

In the present embodiment, as shown in FIGS. 1 and 2 (a) and 2 (b), the algae holding member 6 is arranged so that the algae holding member 6 described later is arranged on or near the water surface 8 in the farm. A support member for supporting is provided. That is, this support member is composed of three ropes 4a, seven ropes 4b, a predetermined number of buoyant bodies 2, and anchor ropes 3a, 3b, and 3c. That is, a total of 12 aquaculture plots 12 are configured by intersecting and connecting the three ropes 4a arranged substantially parallel in the horizontal direction and the seven ropes 4b arranged substantially parallel in the vertical direction. There is.

In each of the aquaculture compartments 12, algae holding members 6a, 6b, 6c, 6d, 6e, and 6f are arranged in parallel in the vertical direction. The materials and shapes of the algae holding members 6a, 6b, 6c, 6d, 6e, and 6f are not particularly limited as long as the algae to be cultivated can be held and grown. For example, in the case of seaweed farming, nets for seaweed farming (so-called seaweed nets) are commercially available, and they can be used as appropriate.

Since the support member is provided with a buoyant body 2 as a component at a position outside each aquaculture section 12, the algae holding members 6a, 6b, 6c, 6d, 6e, and 6f are cultivated in each aquaculture section 12. It is provided so as to be located at or near the water surface 8 in the field. The buoyancy body 2 is not particularly limited, but for example, since buoys for fishing are commercially available, those commercially available buoys can be used.

Anchor rope 3a is further provided on the extension of the rope 4a arranged in the horizontal direction as a component of the support member on the outside of each aquaculture section 12, and is on the extension of the rope 3b arranged in the vertical direction. Anchor rope 3b is provided on the. The ropes 4a and 4b and the anchor ropes 3a and 3b on each drawn line may be formed of the same rope or string, or may be formed by connecting different ropes. The anchor ropes 3a and 3b extend obliquely into the water (see reference numeral 3b in FIG. 2B), and their tips are fixed to the bottom 15 (not shown).

Further, at the intersection of each rope 4a and each rope 4b, and at the position where the buoyant body 2 is arranged, the anchor rope 3c arranged from the intersection toward the water bottom 15 extends vertically. The tip of the anchor rope 3c is fixed to the bottom 15 of the water.

The method of fixing the anchor ropes 3a, 3b, and 3c to the water bottom 15 is not particularly limited, but for example, iron pipes or the like may be connected to the tips of these anchor ropes, and these iron pipes may be fixed by driving them into the water bottom 15. it can.

Further, as shown in FIGS. 2 (a) and 2 (b), in each aquaculture section 12, feeding damage prevention of algae growing on the algae holding members 6a, 6b, 6c, 6d, 6e, 6f is prevented. One net 7 is arranged so as to cover the algae holding members 6a, 6b, 6c, 6d, 6e, and 6f from below. In the present invention, by providing such a feeding damage prevention net, the feeding damage of the cultured algae by the algae-eating fish living in the farm is prevented.

It is essential that the feeding damage prevention net in the present invention is composed of a mesh having a mesh length of 5.5 to 19 cm. Further, it is preferable that the feeding damage prevention net in the present invention has a property of settling when it is floated alone on the water surface in a farm.

If the feeding damage prevention net in the present invention has a property of settling when floating on the water surface in a farm, the feeding damage prevention net can be used as an algae holding member even when the water environment is disturbed due to unseasonable weather or the like. It can be kept in a non-contact state and does not damage the algae growing on the algae holding member. Further, the feeding damage prevention net is arranged at a certain distance from the algae holding member. As a result, the water permeability inherent in the net is maximized, and the water flow and tidal current that are beneficial for the growth of algae in the farm are not hindered, and the growth of algae is not hindered.

As the feeding damage prevention net having the above-mentioned properties in the present invention, if the specific gravity of the material of the net is too small and the net floats on the water surface by itself, a weight or a sink cord is connected to the net. Alternatively, a net made of a material having a specific density larger than the specific density of the constituent water constituting the farm may be used. Considering the trouble of connecting a weight or a sinker cord to the net, it can be said that it is convenient to use the latter net, but it is not particularly limited to the latter. The specific material of the net is not particularly limited, and examples thereof include natural fibers such as hemp and synthetic fibers described later.

When using a net made of a material having a specific density larger than the specific density of the constituent water constituting the farm, specifically when the farm is the sea, the specific gravity of seawater is about 1.020 to 1.024. Therefore, using this as a guide, it is possible to appropriately select a net that can function as a feeding damage prevention net in the present invention by paying attention to the material of the net. As for specific materials, for example, at least selected from the group consisting of nylon fibers (for example, nylon 6, 66, 12, etc., preferably nylon with a high specific gravity such as nylon 66), vinylon fibers, polyester fibers, and fluorocarbon. A net composed of one fiber can be mentioned. Regarding the specific gravity, the net that can function suitably as the feeding damage prevention net in the present invention is a net made of fibers having a high specific density, preferably a net made of polymer fibers having a specific density greater than 1.024. Further, the specific gravity is more preferably more than 1.026, still more preferably 1.1 or more, 1.2 or more, 1.3 or more, for example 1.4 or more, 1.5 or more. The upper limit of the specific gravity is not particularly limited, and examples thereof include 2.60 or less and 2.50 or less, and examples thereof include 1.10 to 2.60 and 1.10 to 2.50.

Examples of the polymer fibers having a high specific density as described above include vinylon fibers, polyester fibers, and fluorocarbon fibers. Further, even if the specific gravity of the fiber polymer itself is relatively small (for example, low specific density nylon or the like), a net made of a high specific density composite fiber in which glass fiber, graphite, silica or the like is composited can be preferably used. A net made of polyester fiber is preferable in terms of high specific density and low cost. More specifically, as the feeding damage prevention net in the present invention, a net material satisfying a predetermined specific gravity condition can be appropriately selected from various commercially available net materials, fishing nets and the like.

As described above, the feeding damage prevention net is composed of a mesh having a mesh length of 5.5 to 19 cm. In the present invention, the mesh length is the length in which the fibers constituting the mesh 7a are linear when the mesh 7a is stretched in the lateral direction (in the direction of the arrow in FIG. 6) as shown in FIG. (Length d in FIG. 6). For example, in commercially available fishing nets, the mesh has a substantially rhombic shape and is formed with the same mesh length, but the net is not limited to such a substantially rhombic shape, and as long as the predetermined mesh length condition is satisfied. It may have a shape such as a substantially circular shape or a substantially elliptical shape, or it may be a combination of meshes having different shapes and sizes. In the case of a mesh such as a substantially circular shape or a substantially elliptical shape, the length of one mesh in a stretched and linear state as shown in FIG. 6 is defined as the mesh length.

As described above, the feeding damage prevention net in the present invention is composed of a mesh having a mesh length of 5.5 to 19 cm, so that the feeding damage of the algae by the algae-eating fish can be effectively prevented, and at the same time, the algae-eating fish. And other small fish can be reduced or prevented from getting caught in the net. Fish get caught in the net, and if this is not removed, the carcasses will rot and inhibit the growth of cultured algae. Further, the work of removing the fish caught in the net from the net requires a great deal of labor and time, and efficient aquaculture cannot be performed. That is, according to the algae cultivation system according to the present invention, it is possible to produce algae with a high production amount by effectively preventing the algae-eating fish from feeding damage to the algae without requiring unnecessary labor for maintenance and the like. It becomes.

In the present invention, the mesh length is preferably about 7 to 16 cm, more preferably about 8 to 16 cm, and even more preferably 9 cm to 15.5 cm. Although not particularly limited, it is possible to use a fishing net having a rhombic mesh within the range of such a mesh length, and the mesh length of the net having such a rhombic mesh is Generally, for example, about 6 cm (2 inch), about 10 cm (3 inch 3 parts), about 12 cm (4 inch), 15 cm (about 5 inch), 18 cm (about 6 cm) and the like can be mentioned. When a net composed of a net having such a mesh length is used as a feeding damage prevention net in the present invention, it is possible to effectively prevent the feeding damage of algae by algae-eating fish, and at the same time, the algae-eating fish and other small fish. Can be more effectively reduced or prevented from being caught in the net.

(Modified Example of Embodiment 1)
Next, a modified example that can be adopted in the first embodiment of the algae farming system called a floating type is shown.

FIG. 3 is a side view of the portion A in FIG. 1 as in FIG. 2 (a). In this modification, in an algae farm system in which one row having the above two aquaculture compartments 12 is arranged in 12 rows in the horizontal direction, a holding member (anchor) constituting a vertical boundary of each aquaculture division as shown in FIG. A structure in which the reinforcing net 17 is suspended from the ropes 3a, 3b, 3c) toward the sea floor is adopted.

Here, the material of the reinforcing net 17 is not particularly limited, but the same material as that of the feeding damage prevention net 7 can be used, and examples thereof include those made of resin such as nylon and polyester. Further, the mesh length can be set in the same manner as the feeding damage prevention net 7.

Further, by connecting a sinker cord to the seabed side of the reinforcing net 17, the reinforcing net 17 can be suspended from the holding members (anchor ropes 3a, 3b, 3c) toward the seabed.

Furthermore, the reinforcing net 17 has a meaning of reinforcing the feeding damage prevention effect of the feeding damage prevention net 7, but as shown in FIG. 3, the mesh surface of the reinforcing net 17 is oriented so as to substantially face the water flow (tide) T. It is preferable to arrange them so as to be. According to the algae farming system having such a configuration, as shown in the following examples, the presence of the reinforcing net 17 weakens the force of the water flow even when a water flow such as a fast tidal current occurs, and prevents feeding damage. Since the force received by the net 7 near the boundary of the aquaculture area 12 is weakened, the feeding damage prevention net 7 does not approach the seaweed net, and the feeding damage by algae-eating fish can be prevented more effectively, and the production amount of seaweed. Can be improved.

[Embodiment 2]
Next, the configuration of the algae farming system 100 according to the second embodiment will be described.
FIG. 4 is a top view schematically showing the algae farming system 100 according to the second embodiment. Further, FIG. 5A is a view of the portion C in FIG. 4 viewed from the side, and FIG. 5B is a view of the portion D in FIG. 5 viewed from the side. Note that FIGS. 4 and 5 (a) and 5 (b) show an algae farming system in a state of being arranged in a farm. The algae farming system 100 according to the present embodiment is a so-called prop-type algae farming system. The configuration will be described below.

In the second embodiment, as shown in FIGS. 4 and 5, eight columns 11 are driven into the water bottom 15 at substantially equal intervals to form one row, and five columns are provided in parallel. The algae holding members 6 are arranged laterally between the columns 11 in the adjacent rows, and a total of four algae holding members 6 are arranged in parallel. As shown in FIGS. 5 (a) and 5 (b), the upper portion of the support column 11 is exposed above the water, and the algae holding member 6 is fixed to the support columns 11 on both sides by the binding rope 13 so that the algae holding member 6 can be used in the farm. It is arranged so as to be located at or near the water surface 8. In the second embodiment, the algae holding member 6 is specifically an algae farming net (for example, a seaweed farming net) as in the first embodiment. In the farm, a support column 11 and a binding rope 13 are provided as support members for supporting the algae holding member 6 so that the algae holding member 6 is arranged on or near the water surface 8.

Further, as shown in FIGS. 5A and 5B, a feeding damage prevention net 7 is arranged on the algae holding member 6 in each row so as to cover the algae holding member 6 from below. The feeding damage prevention net 7 is specifically the same net as in the first embodiment. The net serving as the feeding damage prevention net 7 can also be arranged at a predetermined position by fixing it to the support column with a rope, a rope or the like like the algae holding member 6.

As for the configuration of the second embodiment, the constituent members, and other conditions such as the shape and properties of the constituent members, those as described in the first embodiment can be adopted as long as there is no particular contradiction.
Also in the second embodiment, the advantages and effects described for the first embodiment can be obtained by providing the feeding damage prevention net 7 with the above configuration.

In the algae culture system according to the present invention, the above-mentioned feeding damage prevention net and the algae holding member covering the net are arranged apart from each other to the extent that the algae growing on the algae holding member are not damaged by the algae-eating fish. As long as it is, the distance between the algae holding member and the feeding damage prevention net is not particularly limited. As a guide, it is at least about 30 cm or more, preferably at least about 50 cm or more in the depth direction. Further, by using a net having a flat shape or the like as a feeding damage prevention net, when the feeding damage prevention net covering the algae holding member from below is in a bent state in water, the feeding damage prevention net is said to be at the deepest part where the feeding damage prevention net bends most downward. The distance between the feeding damage prevention net and the algae holding member is, for example, about 1.2 m or more, preferably about 1.3 m or more, more preferably about 1.4 m or more, still more preferably 1.5 or more, and most preferably about 2 m. It may be adjusted so as to be the above. In this case, the upper limit of the distance between the feeding damage prevention net and the algae holding member in the deepest part is not particularly limited, but if it is in an excessively bent state, it may be affected by tidal currents or waves in bad weather. It is generally 5 m or less, preferably 4 m or less, more preferably because it is affected by the wind and may damage each member or the aquaculture system, or even damage the algae growing on the algae holding member. Can be configured to be 3.5 m or less.

<How to produce algae>
The method for producing algae according to the present invention (hereinafter referred to as the production method according to the present invention) includes culturing algae using the algae cultivation system of the present invention. The embodiments and modifications of the algae farming system of the present invention are as shown above.
Hereinafter, specific steps that can be included in the production method of the present invention will be described.

(I) To provide an algae farming system according to the present invention.
The production method of the present invention includes providing the algae farming system according to the present invention at a farm. In this step, unless it is particularly impossible, the members to be components on the ground are assembled in advance, the assembled members are transported to the farm, and other necessary members are combined to relate to the present invention. An algae farming system may be provided to the farm. Alternatively, the algae farming system according to the present invention may be completed by individually transporting the components to the farm and assembling the components at the farm. In particular, the assembly procedure is not limited.

For example, in the algae farming system of the first embodiment, anchor ropes 3a, 3b, 3c, ropes 4a, 4b, buoyant body 2, and feeding damage prevention net 7 are connected in advance on the ground and transported to the farm. , The anchor ropes 3a, 3b, and 3c may be fixed to the bottom 15 so as to have the form shown in FIGS. 1 and 2. Alternatively, the anchor ropes 3a, 3b, 3c, ropes 4a, 4b, buoyant body 2, and feeding damage prevention net 7 may be individually transported to the farm, and the members may be installed and fixed in the predetermined arrangement in FIG. ..
After that, for example, the algae holding member 6 in which algae are sown (for example, a seed net obtained by sowing algae spores on an algae aquaculture net and raising seedlings) is fixed to ropes 4a and 4b in the form shown in FIG. The algae cultivation system of the present invention can be used in the above, and the target algae can be cultivated. In addition, since the algae cultivation system according to the present invention may be constructed in the farm in advance and the algae holding member 6 may be sown with algae spores or the like or may accept algae, the algae cultivation system provided in this step may be added. In, it is not necessary that the algae body is present in the algae holding member 6 at the time of its provision.

Regarding the algae farming system of the second embodiment, for example, the support columns 11 may be erected on the farm in the arrangement shown in FIG. 4, and then the feeding damage prevention net 7 may be fixed to the support columns. After that, the algae holding member 6 in which the algae were sown (for example, the seed net in which the spores of seaweed were sown) was fixed to the rope 4 in the form shown in FIG. Algae can be cultivated.

(Ii) To grow algae for aquaculture purposes.
Needless to say, the production method of the present invention includes growing various algae spores, filaments, seedlings and other algae on the algae holding member. Basically, this process grows algae depending on the water environment in the farm or aquarium, and the configuration of the algae cultivation system of the present invention is set for a certain period of time until the target size and growth stage are reached. The algae retention member may be left in the aquatic environment while being maintained. In this step, the growth status of algae can be monitored regularly, and necessary measures can be taken when a disease occurs, for example. It should be noted that growing algae for aquaculture does not necessarily mean that the algae for aquaculture is grown using the algae farming system of the present invention over the entire life cycle (life history) of the target algae, as shown below. As can be seen from the examples, it also includes culturing using the devised algae culturing system only for a part of the life cycle of the algae for culturing purpose. This is because a predetermined effect can be obtained by using an algae culture system when growing algae for aquaculture in an aquatic environment where algae-eating fish that damage the algae can exist.

(Iii) Harvesting (plucking) the grown algae.
When the algae grow to a predetermined size in the farm, the algae are harvested.
The harvesting method is not particularly limited, but for example, in the case of black seaweed farming, since harvesting methods using suitable vessels and pumps have been established, those harvesting methods should be used as appropriate. Can be done. In addition, relatively large algae can be harvested by, for example, removing the algae holding member from the algae farming system and cutting the grown algae.

(Iv) The production method of the present invention may further include any steps such as washing, drying, processing, packing and / or shipping the harvested algae. In addition, the production method of the present invention produces spores, filaments, seedlings, etc. of algae to be cultivated, and / or sows or plants the produced algae spores, filaments, seedlings, etc. on the algae holding member. Can also be included. For example, regarding the production (aquaculture) of black seaweed, the production method of the present invention is to sow fruit spores on oyster shells and cultivate filaments, and to sow shell spores released from the cultured filaments on a seaweed net. It may also include arbitrary steps such as preparing a seed net by seedlings and raising the seed net in a farm or the like.

<Algae cultivation method>
The method for cultivating algae according to the present invention (hereinafter referred to as the method for cultivating algae according to the present invention) specifically includes the steps (i) and (ii) described above for the production method of the present invention, and harvests the grown algae. That is not an essential process.
The cultivation method according to the present invention can be used, for example, for the purpose of developing / improving a specific algae cultivation method, for investigating and evaluating the water quality environment in a specific water area, for academic research purposes, and the like.

It should be noted that the order of the steps in the production method and the cultivation method of the present invention may be executed simultaneously or sequentially unless there is a particular contradiction and it is not technically impossible. May be good.

<Kit>
The kit according to the present invention includes the following elements and is a kit for constructing an algae culture system according to the present invention.
An instruction that describes (i) a net that functions as a feeding damage prevention net; and (ii) a method for constructing an algae cultivation system and / or a method for producing or cultivating algae using the above algae cultivation system.

The net that functions as a feeding damage prevention net is as described in the algae farming system according to the present invention.

The instructions describing the method for constructing the algae farming system and / or the method for cultivating algae using the above-mentioned algae farming system are the parts and members (feeding damage prevention net) that can be used for constructing the algae farming system according to the present invention. A net that functions as), a procedure for constructing an algae farming system according to the present invention, and / or a description or drawing relating to a method for producing algae or a method for cultivating algae in the present invention. The instructions may be provided on paper, as electronic data stored on a storage medium, as downloadable through a communication line such as the Internet, or displayed on a display. It may be provided by touching.

The kit according to the present invention is convenient for constructing the above-mentioned components (i) and (ii), another component (above) in the algae cultivation system according to the present invention, and the algae cultivation system according to the present invention. Optional components and materials are included. For example, the kit may include a seaweed net as an algae holding member, a rope and a buoyant body as the supporting member, and the like, particularly for the purpose of providing an algae farming system used for algae farming.

From November 2016 to mid-March 2017, the present inventor of black seaweed using the stratified aquaculture system shown in the following comparative examples and examples at a seaweed farm off the coast of Shimosu Fishing Port in Futtsu City, Chiba Prefecture. Aquaculture was carried out. In Example 1, an aquaculture system was constructed at a farm in late December 2016, and black seaweed was cultivated using the same aquaculture system in January 2016. Further, Examples 2 to 4 were carried out in order after January 2017. Furthermore, in Examples 5 to 14, black seaweed was cultivated by constructing a predetermined seaweed cultivation system from November 2017 to April 2018.

(Common conditions)
In each example and each comparative example, aquaculture was carried out in accordance with the standards for black seaweed cultivation established by the Chiba Prefectural Fisheries Cooperative Association, except for the conditions shown below. That is, unless otherwise specified, the seaweed was carried out based on a general seaweed cultivation method, and the seaweed harvested in the examples and comparative examples was processed into nori seaweed and shipped.

To briefly explain the method of nori cultivation, first, around February to March, oyster shells were sprinkled with fruit spores and filamentous bodies were cultured. Around mid-September, a seed net was prepared by sowing the shell spores released from the cultured filaments into a seaweed net, that is, collecting seedlings. The prepared seed net was stored in a freezer at −30 ° C. until the seedling raising step. Then, from the beginning to the middle of October, the seed nets were raised in the farm where the water temperature dropped and the temperature became appropriate. The seed nets that had been raised were tested for aquaculture using the algae aquaculture system according to each example and each comparative example.

The material, dimensions (width 1.2 m x length 18 m), mesh shape (diamond) and mesh length of the seaweed net (corresponding to the algae holding member in the present invention) used in each Comparative Example and each Example are the same. A seed net (spores were sown and raised) prepared under the same conditions using a seaweed net was planted in each algae culture system.

More specifically, at the seaweed farm off the coast of Shimosu Fishing Port in Futtsu City, Chiba Prefecture, one aquaculture system (seaweed farming system) is provided with two farming sections in a row in the vertical direction during the seaweed farming season. This was arranged in 12 rows in the horizontal direction. At this farm, seven of these algae farming systems were installed. Explaining with reference to FIG. 1, in the aquaculture system of FIG. 1, two aquaculture compartments 12 are provided in one vertical row, and the aquaculture compartments 12 in the one row are arranged in six rows in the horizontal direction. However, in the aquaculture system according to each of the examples and the comparative examples, the aquaculture system is arranged in 12 rows instead of 6 rows in the horizontal direction. One aquaculture plot has a vertical width of 25 m and a horizontal width of 12 m. These aquaculture plots are specifically composed of ropes having buoyant bodies called infant ropes.

The aquaculture plots of the above seven algae farming systems were jointly used by the fishery association to which the present inventor belongs, and the inventor has a total of 23 rows of aquaculture plots for one vertical row. Minutes were allocated and the aquaculture tests according to the following examples and comparative examples were carried out.
That is, seaweed was cultivated in each of these 23 rows by adopting the configuration of the algae culturing system according to each Example and each Comparative Example as described in detail below. It should be noted that 6 seaweed nets (seed nets) can be planted in one section, that is, 12 nets / row x 23 rows = 276 seed nets were always planted.

After first planting the seed net, when the black seaweed grew to about 20 to 30 cm, it was cut leaving about 7 cm, and when it grew to about 20 to 30 cm with an interval of 5 to 7 days, the second cutting was performed. For the same seaweed net, this cutting work was performed 5 to 7 times in total to harvest black seaweed. Black seaweed was harvested from about 48 to 60 sheets of seaweed net per day. The reason why the number of seaweed nets cut in one day is different is that the growth condition of seaweed is inevitably different at each harvest, and the seaweed nets targeted for harvesting to secure the yield of seaweed above a certain level. Because the number of is different from day to day.

In Examples and Comparative Examples, the number of Nori seaweed obtained by finally processing the raw Nori seaweed harvested on each harvest day is divided by the number of Nori seaweed nets harvested from the raw Nori seaweed. The amount of Nori seaweed produced per sheet was calculated, and the effect of preventing feeding damage was evaluated by comparing the amount of production of Examples and Comparative Examples. Needless to say, in each of the Examples and Comparative Examples, the Nori seaweed was processed under the same conditions and with the same dimensions (general dimensions on the market).

<Comparison of the present invention and the prior art>
Hereinafter, the configuration and the like of the algae aquaculture system used in Examples 1 to 4 and Comparative Examples 1 and 2 will be described in detail.
[Example 1]
The algae farming system according to this embodiment was constructed by imitating the configuration of the algae farming system 10 according to the first embodiment shown in FIGS. 1 and 2 (a) and 2 (b), and black seaweed was cultivated. .. The difference from the first embodiment is the number of rows of aquaculture plots in the lateral direction (hereinafter, the same applies to Examples 2 to 4 and Comparative Examples 1 and 2). In this example, a commercially available nylon fishing net (mesh length 3.3 inch; about 10 cm) was used as the feeding damage prevention net 7. In addition, the specific gravity of nylon fiber, which is the material of the fishing net, was 1.14. The feeding damage prevention net 7 is configured such that when the feeding damage prevention net 7 is installed in each aquaculture section, the vicinity of the center of the feeding damage prevention net 7 bends downward in water as shown in FIGS. 2 (a) and 2 (b). It is added that the one with the following dimensions was selected. This is the same in Examples 2-4.

[Example 2]
Similar to the first embodiment, the algae farming system according to the present embodiment is constructed by imitating the configuration of the algae farming system 10 according to the first embodiment shown in the outline, FIGS. 1 and 2 (a) and 2 (b), and black. Nori was cultivated. However, while a nylon fishing net (mesh length 3.3 inch; about 10 cm) was used as the feeding damage prevention net 7 in Example 1, a polyester net (mesh length 3.3 inch; about 10 cm) was used in this example. Was used as the feeding damage prevention net 7. The specific gravity of the polyester fiber, which is the material of the net, was 1.38.

[Example 3]
Similar to the first embodiment, the algae farming system according to the present embodiment is constructed by imitating the configuration of the algae farming system 10 according to the first embodiment shown in the outline, FIGS. 1 and 2 (a) and 2 (b), and black. Nori was cultivated. However, in this embodiment, a nylon fishing net (mesh length 3.3 inch; about 10 cm) in which a sinker cord is arranged and connected along the longitudinal direction at the center in the lateral direction is used as the feeding damage prevention net 7.

[Example 4]
Similar to the first embodiment, the algae farming system according to the present embodiment is constructed by imitating the configuration of the algae farming system 10 according to the first embodiment shown in the outline, FIGS. 1 and 2 (a) and 2 (b), and black. Nori was cultivated. However, in this embodiment, two sinker cords are arranged and connected along the longitudinal direction at positions 1.5 m inward from both sides in the lateral direction of a nylon fishing net (mesh length 3.3 inch; about 10 cm). The thing was used as the feeding damage prevention net 7.

[Comparative Example 1]
Black seaweed was cultivated using an algae culturing system having the same structure as in Example 1 except that a member corresponding to the feeding damage prevention net 7 was not provided.

[Comparative Example 2]
The algae culture system according to this comparative example was constructed by imitating the configuration of the algae culture system 200 shown in FIGS. 7 (a) and 7 (b), and black seaweed was cultivated. That is, in the algae culture system, the feeding damage prevention net 9 extending in the vertical direction toward the seabed 15 is provided, but the feeding damage prevention net 9 does not reach the seabed 15. As the feeding damage prevention net 9, a commercially available nylon fishing net (mesh length 3.3 inch; about 10 cm) was used, and the specific gravity of the nylon fiber used as a material was 1.14. In addition, a weight 11 was connected to the lower part of the feeding damage prevention net 9.

<Results of Examples 1 to 4 / Comparative Examples 1 and 2>
Table 1 below shows the presence or absence of a feeding damage prevention net in the algae cultivation system according to Examples 1 to 4 and Comparative Examples 1 and 2, various conditions for the feeding damage prevention net, and the amount of nori seaweed produced per seaweed net. Shown.

First, in Comparative Example 1 in which no member corresponding to the feeding damage prevention net was provided, when the same kind net was visually confirmed 5 to 7 days after the seed net (nori net) was planted, it almost grew. Nori could not be confirmed, and some of the seaweed was shorter or missing than when it was planted. That is, in practice, none of the seed nets was in a state where seaweed could be harvested. Therefore, as shown in Table 1, the production amount of Comparative Example 1 was 0.

Next, in Comparative Example 2 imitating the conventional algae farming system shown in FIG. 7, since the means for preventing the feeding damage of the farmed algae by the algae-eating fish was provided, the seaweed could be harvested and one seaweed net was provided. Although the production amount of 200 to 300 pieces could be secured per unit, the production amount was considerably lower than the normal yield amount without feeding damage by algae-eating fish. When the algae cultivation system of Comparative Example 2 was constructed and the seaweed cultivation was started, the production amount was relatively high, but after the start of the cultivation, the production amount tends to decrease as the days pass. Was done. Initially, algae-eating fish did not invade the inside of the algae farming system because they were wary of the existence of a feeding damage prevention net, but over time, algae-eating fish moved from the bottom of the algae-eating fish system directly under the seaweed net. It was presumed that the algae-eating fish caused feeding damage later because they learned that they could invade the area.

On the other hand, in Example 1 in which the configuration of the present invention was adopted, a fishing net made of nylon having a relatively small specific density was used as the feeding damage prevention net, but the production amount recovered remarkably to 400 to 500 pieces. Regarding the algae aquaculture system according to Example 1, although there was a problem that a part of the algae aquaculture system was broken due to the floating of the feeding damage prevention net when the strong wind blew and the sea condition deteriorated, the production thereof. The amount was practically sufficient.

Further, in Examples 2 to 4 in which the feeding damage prevention net having a property of sinking into water more than the feeding damage prevention net in the algae cultivation system of Example 1 was adopted, the seaweed net 1 was compared with the comparative example. We were able to secure an extremely high production volume of 500 to 600 sheets per sheet. In addition, in Examples 2 to 4, even when a strong wind blows and the sea condition deteriorates, the feeding damage prevention net does not float and the algae aquaculture system is not destroyed. ..

In particular, in Example 2, by adopting a polyester net having a relatively high specific density for the feeding damage prevention net, a simple configuration is used without providing a sinking cord as used in Examples 3 and 4. We were able to secure an extremely high production volume of 500 to 600 sheets per seaweed net.

As described above, according to the algae cultivation system according to the present invention and the algae cultivation method (production method and cultivation method) using the algae cultivation system, it is possible to prevent algae feeding damage by algae-eating fish at a high level, and an extremely high production amount can be achieved. It was proved that it could be secured.

<Degree of deflection of the feeding damage prevention net in the sea>
Next, an example in which the dimension of the feeding damage prevention net 7 is changed to change the degree of deflection in the sea will be shown.
[Example 5]
In this embodiment, the dimensions of the commercially available nylon fishing net (mesh length 3.3 inch; about 10 cm) used as the feeding damage prevention net 7 in Example 1 are converted into meshes in the vertical width (vertical direction in FIG. 1). An algae farming system was constructed in the same manner, and black seaweed was cultivated, except that the width of 250 stitches and the width (horizontal direction in FIG. 1) were changed to 150 stitches in terms of mesh.
In this embodiment, the dimensions of the feeding damage prevention net 7 were changed as described above, so that the distance between the feeding damage prevention net 7 and the seaweed net in the depth direction was 1. It was about 5 m.

[Example 6]
In this embodiment, the dimensions of the commercially available nylon fishing net (mesh length 3.3 inch; about 10 cm) used as the feeding damage prevention net 7 in Example 4 are converted into meshes in the vertical width (vertical direction in FIG. 1). An algae cultivation system was constructed in the same manner, and black seaweed was cultivated, except that the 330th stitch and the width (horizontal direction in FIG. 1) were changed to 180th stitch in terms of mesh.
In this embodiment, by changing the dimensions of the feeding damage prevention net 7 as described above, the distance between the feeding damage prevention net 7 and the seaweed net in the depth direction is about 3 m near the central part of the aquaculture area where the two are most distant from each other. It was about 30 cm even in the vicinity of the seaweed net, which is relatively close to each other.

[Example 7]
In this example, except that the feeding damage prevention net 7 was changed to a polyester net (mesh length 3.3 inch; about 10 cm) in Example 6, an algae cultivation system was constructed in the same manner, and black seaweed was cultivated. went. In this embodiment, the dimensions of the feeding damage prevention net 7 are 330 stitches in terms of vertical width (vertical direction in FIG. 1) and 180 stitches in horizontal width (horizontal direction in FIG. 1) in terms of mesh, as in Example 6. Is.
As in Example 6, the distance between the feeding damage prevention net 7 and the seaweed net in the depth direction is about 3 m near the central part of the aquaculture area where the two are most distant, and the area around the seaweed net where the two are relatively close to each other. It was about 30 cm even near the part.

[Example 8]
In this embodiment, the dimensions of the commercially available nylon fishing net (mesh length 3.3 inch; about 10 cm) used as the feeding damage prevention net 7 in Example 1 are converted into meshes in the vertical width (vertical direction in FIG. 1). An algae cultivation system was constructed in the same manner, and black seaweed was cultivated, except that the 400th mesh and the horizontal width (horizontal direction in FIG. 1) were changed to 300th mesh in terms of mesh.
In this embodiment, by changing the dimensions of the feeding damage prevention net 7 as described above, the feeding damage prevention net was sunk to the extent that it could not be seen from the sea in the vicinity of the central part of the aquaculture area where the two were farthest apart.

[Comparative Example 3]
In this embodiment, the dimensions of the commercially available nylon fishing net (mesh length 3.3 inch; about 10 cm) used as the feeding damage prevention net 7 in Example 1 are converted into meshes in the vertical width (vertical direction in FIG. 1). An algae cultivation system was constructed and black seaweed was cultivated in the same manner as in Example 1 except that the width of 200 stitches and the width (horizontal direction of FIG. 1) were changed to 90 stitches in terms of mesh.
In this embodiment, by changing the dimensions of the feeding damage prevention net 7 as described above, the feeding damage prevention net 7 is hardly bent in the sea, and the feeding damage prevention net 7 and the seaweed net are almost in contact with each other. Even if there was a part where the feeding damage prevention net 7 and the seaweed net were separated, the distance between them was about 3 to 5 cm.

(Results of Examples 5 to 8 / Comparative Example 3)
In Example 5, as described above, the distance between the feeding damage prevention net 7 and the seaweed net in the depth direction was about 1.5 m in the vicinity of the central part of the aquaculture area where the two were most distant from each other.
When strong winds or large waves are generated due to bad weather, the feeding damage prevention net 7 and the seaweed net may come into contact with each other, and the grown seaweed may be damaged, cut and shortened. The effect of preventing feeding damage was observed.

Further, in Examples 6 and 7, the feeding damage prevention net 7 and the seaweed net were about 3 m in the vicinity of the central part of the aquaculture area where they were most separated from each other, and about 30 cm in the vicinity of the seaweed net peripheral part where the two were relatively close to each other. Was able to effectively prevent the feeding damage of seaweed by algae-eating fish, obtained an extremely good yield of seaweed, and was able to avoid the adverse effects of bad weather as seen in Example 5.

Further, in Example 8 in which the feeding damage prevention net was sunk to the extent that it could not be seen from the sea near the central part of the aquaculture area, the feeding damage prevention net became an anchor rope or the like when a strong wind, a large wave or a fast tidal current occurred due to bad weather. Although it was sometimes entangled and damaged, the effect itself of preventing the feeding damage of seaweed by algae-eating fish was sufficiently recognized.

On the other hand, in Comparative Example 3 in which the feeding damage prevention net and the seaweed net were in almost contact with each other, the growth of seaweed was observed at the beginning after the seed net was installed in the aquaculture area, but the seaweed was damaged and grew after about 3 days. The seaweed was also shortened.

<Modification example according to the first embodiment: A configuration in which a reinforcing net 17 is adopted in addition to the feeding damage prevention net 7>
[Example 9]
An algae culture system was constructed and black seaweed was cultivated in the same manner as in Example 4, except that the configuration of the modified example shown in FIG. 3 was adopted. Hereinafter, the configuration of this embodiment will be specifically described.
FIG. 3 is a side view of the portion A in FIG. 1 as in FIG. 2 (a). In this embodiment, in an algae farm system in which one row having the above two aquaculture plots 12 is arranged in 12 rows in the horizontal direction, the aquaculture division assigned to the present inventor is damaged by feeding as shown in FIG. In addition to the provision of the prevention net 7, a structure in which the reinforcing net 17 is hung from the anchor rope forming the vertical boundary of each aquaculture division toward the sea floor is adopted. A commercially available nylon fishing net (mesh length 3.3 inch; about 10 cm) is used for the reinforcing net 17, and the dimensions are 21 m in the vertical width (vertical direction in FIG. 1) and the horizontal width (width in the depth direction). ) Was 2 m. By connecting the sink cords along the seabed side of the reinforcing net 17, the reinforcing net 17 is suspended from the anchor rope forming the vertical boundary of each aquaculture division toward the seabed. After adjustment, the aquaculture system was configured so that the mesh surface of the reinforcing net 17 was oriented so as to substantially face the tidal current T as shown in FIG.

[Example 10]
An algae culture system was constructed and black seaweed was cultivated in the same manner as in Example 2 except that the configuration of the modified example shown in FIG. 3 was adopted.
That is, in Example 5, a commercially available nylon fishing net (mesh length 3.3 inch; about 10 cm; specific gravity 1.14) was used as the feeding damage prevention net 7, whereas in this example, polyester was used as the feeding damage prevention net 7. A net (mesh length 3.3 inch; about 10 cm; specific gravity 1.38) was used as the feeding damage prevention net 7. The reinforcing net 17 uses a commercially available nylon fishing net (mesh length 3.3 inches; about 10 cm) similar to that of the ninth embodiment, and its dimensions and the method of connecting to the aquaculture system are the same as those of the ninth embodiment. ..

(Results of Examples 9 and 10)
In Examples 9 and 10, it was confirmed that feeding damage by algae-eating fish can be further effectively prevented as compared with Examples 1 to 8 in which the reinforcing net 17 is not adopted.
More specifically, in the configurations of Examples 1 to 8 in which the reinforcing net 17 is not adopted, in an environment where the tidal current is fast, when the feeding damage prevention net 7 receives a larger force of the fast tidal current, the boundary on the upstream side of the tidal current of the aquaculture area 12 Since the feeding damage prevention net 7 is pushed by the tidal current and approaches the seaweed net in the vicinity, the aquaculture fish learned that the feeding damage prevention net 7 can prey on the seaweed near the boundary near the seaweed net. There was a case of feeding damage.
On the other hand, in Examples 9 and 10 in which the reinforcing net 17 is adopted in addition to the feeding damage prevention net 7, the force of the tidal current is weakened due to the presence of the reinforcing net 17 even when a fast tidal current occurs. Since the force received by the feeding damage prevention net 7 near the boundary of the aquaculture area 12 is weakened, the feeding damage prevention net 7 does not come so close to the seaweed net, and the feeding damage by algae-eating fish can be prevented more effectively. It was shown that the production volume of
There was no noticeable difference in the feeding damage prevention effect between Example 9 and Example 10, and a remarkable feeding damage prevention effect was observed in both cases.

<Example of changing the mesh length of the feeding damage prevention net>
[Example 11]
In this example, an algae cultivation system was constructed and black seaweed was cultivated in the same manner as in Example 1 except that a commercially available nylon fishing net (mesh length 2 inch; about 6 cm) was used as the feeding damage prevention net 7. Was done.

[Example 12]
In this example, an algae cultivation system was constructed and black seaweed was cultivated in the same manner as in Example 4, except that a commercially available nylon fishing net (mesh length 4 inch; about 12 cm) was used as the feeding damage prevention net 7. Was done. That is, the nylon fishing net used as the feeding damage prevention net 7 has two sinker cords arranged and connected along the longitudinal direction at positions 1.5 m inward from both sides in the lateral direction.

[Example 13]
In this embodiment, a commercially available nylon fishing net (mesh length 5 inch; about 15 cm) is used as the feeding damage prevention net 7, except that two sinker cords are connected diagonally to the feeding damage prevention net 7. Similar to Example 1, an aquaculture system was constructed and black seaweed was cultivated.

[Example 14]
In this example, an algae cultivation system was constructed and black seaweed was cultivated in the same manner as in Example 4, except that a commercially available nylon fishing net (mesh length 6 inch; about 18 cm) was used as the feeding damage prevention net 7. went. That is, the nylon fishing net used as the feeding damage prevention net 7 has two sinker cords arranged and connected along the longitudinal direction at positions 1.5 m inward from both sides in the lateral direction.

In Examples 11 to 14, it should be noted that the mesh length of the nylon fishing net used as the feeding damage prevention net 7 was changed.
In any of Examples 11 to 14, a certain level of feeding damage prevention effect was observed, and an improvement in the production amount of seaweed was observed.
In terms of the feeding damage prevention effect, there was no problem in any of Examples 11 to 14, but in Example 14 in which the mesh length of the feeding damage prevention net 7 was about 18 cm, there was an example in which another smaller mesh length was adopted. By comparison, the effect of preventing feeding damage tended to be slightly inferior. Further, in Example 11 in which the mesh length of the feeding damage prevention net 7 is about 6 cm, there is no problem in the feeding damage prevention effect, but the mesh is small when the diatoms adhering to the feeding damage prevention net 7 grow after a predetermined period. Therefore, it was observed that the mesh of the feeding damage prevention net 7 was blocked with diatoms, and in some cases, a part of the seaweed to be cultivated died or rotted.
Examples 12 in which the mesh length of the feeding damage prevention net 7 is about 12 cm, Example 13 in which the mesh length of the feeding damage prevention net 7 is about 15 cm, and Examples 1 to 4 in which the mesh length of about 10 cm is adopted are algae-eating. The effect of preventing the feeding damage of the seaweed by fish was high, and the seaweed did not die or rot as in Example 11, and high quality seaweed could be produced with good yield.
Further, in Example 13 in which two sinker cords are connected diagonally to the feeding damage prevention net 7, the deflection of the feeding damage prevention net 7 is particularly less affected by tidal currents and bad weather, and a good yield of seaweed can be obtained. A tendency was observed.

Although the specific embodiments and examples of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments and examples. Various modifications, modifications, and arbitrary combinations may be adopted for each configuration, element, and feature without departing from the gist of the present invention.

2 Buoyant bodies 3a, 3b, 3c Anchor ropes 4, 4a, 4b Rope 6, 6a, 6b, 6c, 6d, 6e, 6f Algae holding member 7 Eating damage prevention net 7a Mesh 8 Water surface (sea surface)
9 Conventional feeding damage prevention net 10, 100 Algae cultivation system 11 Strut 12 Culture section 13 Tie rope 15 Water bottom (seabed)
17 Reinforcing net 18 Algae-eating fish 200 Conventional algae farming system T Arrow indicating the direction of water flow (tide)

Claims (1)

(A) At least one algae holding member and
(B) A support member that supports the algae holding member so that at least one algae holding member is arranged on or near the water surface in the farm.
(C) A feeding damage prevention net that prevents algae from being eaten by algae-eating fish at the above farms,
With
The feeding damage prevention net is arranged so as to cover at least one algae holding member from below in the farm.
The feeding damage prevention net and the algae holding member are arranged apart from each other so that the algae growing on the algae holding member are not damaged by the algae-eating fish.
The feeding damage prevention net is composed of a mesh having a mesh length of 5.5 cm to 19 cm.
Algae farming system.

Images