Methods of creating algal fields

Abstract

To provide a method for creating seaweed beds that is inexpensive and does not require the use of vegetation substrate materials. [Solution] The present invention provides a method for creating a seaweed bed, which includes covering the area to be created 10A with a seaweed bed creation device 11 capable of blocking water flow, and scattering algal eggs on the area to be created 10A covered by the seaweed bed creation device 11. According to the seaweed bed creation method of the present invention, since the area to be created 10A is covered with the seaweed bed creation device 11, the algal eggs scattered on the area to be created 10A covered by the seaweed bed creation device 11 are not washed away by water flow, and the rate of attachment to the area to be created 10A can be increased.

Description

Technical Field

[0001] The present invention relates to a method for creating a seaweed bed.

Background Art

[0002] Rock burning is a phenomenon in which seaweed decreases and the seabed becomes desertified. The main causes of rock burning are an increase in herbivorous organisms (such as sea urchins and abalones), an increase in seawater temperature, a shortage of nutrients, and artificial destruction of the seabed environment. When seaweed is lost due to rock burning, there is a problem that the habitats and feeding grounds of fish and shellfish decrease, and the entire marine ecosystem becomes unstable.

[0003] Therefore, conventionally, various methods for creating a seaweed bed have been studied. For example, in Patent Document 1, a net having a raised portion is stretched over a natural coconut fiber mat, and vegetation of aquatic plants is performed on the entire upper surface of the natural coconut fiber mat, so that even if the aquatic plants outside the raised portion formed by the net are eaten by grass carp or the like, the aquatic plants inside the net are protected.

[0004] Also, in Patent Document 2, a block or structure made of a cement-based material such as concrete is treated using a porous material of a mineral that is easy for seaweed to adhere to on the surface, or a block or structure is produced by treating it so as to have a surface structure equivalent thereto and installed in seawater, or a net bag filled with the porous material of the mineral as it is is exposed in the sea to construct an artificial fishing reef where a seaweed bed is formed and seaweed thrives, and a method for improving the habitat environment of fish and shellfish is disclosed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The conventional method of creating seaweed beds described above involves planting aquatic plants on vegetation base materials such as natural coconut fiber mats or blocks, and then placing them on the seabed while protecting them with nets or mesh bags. As a result, the cost of creating seaweed beds is very high, making it difficult to create seaweed beds over a wide area.

[0007] Therefore, the objective of the present invention is to provide a method for creating seaweed beds that can be done inexpensively without using vegetation substrate materials. [Means for solving the problem]

[0008] The present invention provides a method for creating a seaweed bed, characterized by covering the area to be created as a seaweed bed with a covering capable of blocking water flow, and scattering algal eggs or spores onto the area covered by the covering. According to the present invention's method for creating a seaweed bed, since the area to be created as a seaweed bed is covered with the covering, the algal eggs or spores scattered onto the area covered by the covering are not washed away by water flow, thereby increasing the rate of attachment to the area.

[0009] By removing the covering material after a predetermined period has elapsed since the eggs or spores were dispersed, the growth of algae after implantation is no longer inhibited by the covering material.

[0010] It is preferable to disperse the eggs or spores through a mesh designed to separate them from each other. This allows for separation and establishment of the eggs or spores on the target area, even if they are adhered together and clustered.

[0011] Furthermore, the present invention's method for creating a seaweed bed is characterized by including placing the reproductive bed of algae or algal bodies containing the reproductive bed on the area to be created for seaweed bed formation, and covering the reproductive bed of algae or algal bodies containing the reproductive bed placed on the area to be created with a covering that can block water flow, along with the area to be created. According to the present invention's method for creating a seaweed bed, algal eggs or spores fall from the reproductive bed of algae onto the area covered with the covering and settle on the area to be created, thereby preventing the algal eggs or spores from being carried away by water flow and increasing the rate of settlement on the area to be created.

[0012] Furthermore, by removing the covering after a predetermined period, the growth of algae after implantation will no longer be inhibited by the covering.

[0013] It is desirable to place the reproductive beds of algae, or algal bodies containing reproductive beds, in a net and then place them on the growing area. This prevents the reproductive beds from scattering. [Effects of the Invention]

[0014] According to the seaweed bed creation method of the present invention, the rate at which algal eggs or spores can be established on the area to be created can be increased without being washed away by the water current, making it possible to create seaweed beds inexpensively without using vegetation substrate materials. [Brief explanation of the drawing]

[0015] [Figure 1] This is an explanatory diagram showing a method for creating a seaweed bed according to the first embodiment of the present invention. [Figure 2] This is an explanatory diagram showing a method for creating a seaweed bed according to a second embodiment of the present invention. [Figure 3] This is an explanatory diagram showing a method for creating a seaweed bed according to a third embodiment of the present invention. [Figure 4] This is an explanatory diagram showing a method for creating a seaweed bed according to a fourth embodiment of the present invention. [Modes for carrying out the invention]

[0016] <Embodiment 1> FIG. 1 is an explanatory diagram showing a method for creating a seaweed bed according to the first embodiment of the present invention. In FIG. 1, in the method for creating a seaweed bed according to the first embodiment of the present invention, a seaweed bed is created on the rock 10 on the seabed. In the method for creating a seaweed bed in this embodiment, a seaweed bed creating device 11 as a covering body that covers the created portion 10A, which is the range for creating the seaweed bed on the rock 10, is used.

[0017] The seaweed bed creating device 11 has a dome-shaped covering portion 12 that covers the created portion 10A. The covering portion 12 is formed of a material such as glass or plastic that does not allow water to pass through, and blocks the water flow to the created portion 10A. The bottom of the covering portion 12 is open. Also, a net 13 is provided at the bottom of the covering portion 12. An injection port 14 for injecting eggs or spores of algae is formed at the upper part of the covering portion 12.

[0018] The algae applied to the method for creating a seaweed bed in this embodiment are algae such as seaweed that are not seed plants. Algae perform photosynthesis, but are a group of organisms with unclear leaves, stems, and roots, and mainly inhabit fresh water and seawater. As algae, green algae (such as sea lettuce, curly laver, etc.), brown algae (such as kelp, wakame, hijiki, sea bamboo, acamoc, yatsumata mok, etc.), and red algae (such as nori, tengusa, funori, etc.) can be applied. Note that sea grass classified as a seed plant such as eelgrass is not applicable to the present invention.

[0019] In the method for creating a seaweed bed in this embodiment, as shown in FIG. 1, the seaweed bed creating device 11 is installed on the created portion 10A, and eggs or spores of algae are injected into the covering portion 12 from the injection port 14 using an injector 15 such as a syringe or a dropper, and thus scattered on the created portion 10A. The eggs or spores of algae are fertilized eggs (embryos) or spores collected from mature algae. These eggs or spores of algae will flow away before settling on the created portion 10A when there is water movement, but by using the seaweed bed creating device 11, the settlement rate on the created portion 10A increases without being washed away by the water flow.

[0020] Incidentally, the eggs or spores of algae may adhere and aggregate to each other. The mesh size of the net 13 at the bottom of the covering portion 12 is slightly larger than the size of the eggs or spores of algae, that is, the size is such that the aggregated eggs or spores can be separated by passing through this mesh. Thereby, even when the eggs or spores adhere and aggregate to each other, they can be separated by being scattered through the mesh and fixed onto the formation part 10A.

[0021] And after a predetermined period (for example, several hours (half a day) to 1 day) has elapsed since the eggs or spores of algae are scattered, the seaweed bed formation device 11 is removed from above the formation part 10A. Thereby, the eggs or spores of algae are fixed and grow on the formation part 10A without being washed away by the water flow. Incidentally, before scattering the eggs or spores, if there are attachments (such as miscellaneous seaweeds, small stones, and dust) on the formation part 10A that may prevent the eggs from adhering, it is desirable to remove them.

[0022] As described above, according to the seaweed bed formation method in the present embodiment, since the eggs or spores of algae can be prevented from being washed away by the water flow and the fixation rate onto the formation part 10A can be increased, it is possible to form a seaweed bed at a low cost.

[0023] <Embodiment 2> FIG. 2 is an explanatory diagram showing the seaweed bed formation method in the second embodiment of the present invention. In FIG. 2, in the seaweed bed formation method in the second embodiment of the present invention, a seaweed bed is formed over a wide area such as the seabed rock 20. In the seaweed bed formation method in the present embodiment, a covering sheet 21 as a covering body that covers the formation part 20A of the area where the seaweed bed is to be formed on this rock 20 is used.

[0024] The covering sheet 21 is formed of a water-impermeable material such as vinyl and blocks the water flow to the formation part 20A. Weights 22 such as chains or lead are attached to the covering sheet 21 so that it is not blown away by the water flow. The periphery of the covering sheet 21 is installed so as to prevent the intrusion of water flow as much as possible. Incidentally, weights such as chains or lead may be attached to the aforementioned seaweed bed formation device 11 as well so that it is not blown away by the water flow.

[0025] In the seaweed bed creation method of this embodiment, as shown in Figure 2, a covering sheet 21 is placed on the area to be created 20A, and algal eggs or spores are scattered onto the area to be created 20A using an injector such as a syringe or dropper (not shown) through small holes 21A made at key points on the covering sheet 21. Alternatively, instead of holes 21A, the injector can be inserted into the gap between the covering sheet 21 and the rock mass 20 from the outer circumference of the covering sheet 21 and scattered. Furthermore, as mentioned above, in case the algal eggs adhere to each other and aggregate, a net similar to the net 13 described above may be provided at the tip of the injector.

[0026] After a predetermined period (for example, several hours (half a day) to one day) has elapsed since scattering the algal eggs or spores, the covering sheet 21 is removed from the area to be created 20A. This allows the algal eggs or spores to settle and grow on the area to be created 20A without being washed away by the water current.

[0027] As described above, in the seaweed bed creation method of this embodiment, the rate at which algal eggs or spores can settle on the area to be created 20A can be increased without being carried away by the water current, making it possible to create seaweed beds at low cost.

[0028] <Embodiment 3> Figure 3 is an explanatory diagram showing a method for creating a seaweed bed in a third embodiment of the present invention. In Figure 3, the seaweed bed creation method in the third embodiment of the present invention creates a seaweed bed on a rock 30 on the seabed. In the seaweed bed creation method in this embodiment, a triangular pyramidal covering bag 31 is used as a covering to cover the entire rock 30 which is the part to be created.

[0029] The conical pyramidal covering bag 31 completely covers the rock 30, thereby preventing water flow around the rock 30. The bottom of the covering bag 31 is secured with a weight 32. In this conical pyramidal covering bag 31, a small amount of air accumulates at the apex of the pyramid, allowing it to maintain its three-dimensional shape. Algal eggs or spores are dispersed using an injector through small holes opened on the side of the covering bag 31.

[0030] After a predetermined period (for example, several hours (half a day) to one day) has elapsed since the scattering of algal eggs or spores, the covering bag 31 is removed. This allows the algal eggs or spores to settle on the rock 30 without being washed away by the water current and to grow.

[0031] As described above, in the seaweed bed creation method of this embodiment, the rate at which algal eggs or spores can be attached to the rocks 30 without being carried away by the water current can be increased, making it possible to create seaweed beds at low cost.

[0032] <Embodiment 4> In the first to third embodiments of the present invention described above, the method for creating seaweed beds involves scattering algal eggs or spores onto the area to be created, which is covered by a covering. In this case, it is necessary to collect eggs (fertilized eggs (juvenile embryos)) or spores from mature algae, but this collection work is not easy. Therefore, in the fourth embodiment of the present invention, instead of algal eggs or spores, the reproductive bed of the algae, or the algal body including the reproductive bed, is covered together with the area to be created by a covering that can block water flow.

[0033] Figure 4 is an explanatory diagram showing a method for creating a seaweed bed according to the fourth embodiment of the present invention. As shown in Figure 4, in the fourth embodiment of the present invention, the method for creating a seaweed bed involves placing the reproductive organ bed 41 of the algae into a net 42 and arranging it on the area to be created 40 where the seaweed bed is to be created. The net 42 containing the reproductive organ bed 41, along with the area to be created 40, is covered with a covering body 43 that can block water flow. A weight 44 is attached to the covering body 43 to prevent it from being washed away by the water flow.

[0034] As a result, algal eggs or spores fall from the algal reproductive bed 41 onto the covered area 40, which is covered by the covering body 43, and settle on the area 40. This prevents the algal eggs or spores from being washed away by the water current, thereby increasing the rate of attachment to the area 40.

[0035] Alternatively, instead of directly placing the reproductive bed 41 into the net 42, the algal body containing the reproductive bed 41 may be placed into the net 42. In this case, the algal body should be one in which the reproductive bed 41 has already formed. Since the reproductive bed 41 is only formed during the maturation stage, placing algal body in the covering body 43 during a period when the reproductive bed 41 has not yet formed will not be effective.

[0036] For example, in sexually reproducing species such as Sargassum and Sargassum fuciformis, male and female reproductive foci are formed on the reproductive bed 41, and sperm and eggs are produced. The eggs attach to the surface of the reproductive bed 41 and are fertilized. After fertilization, the eggs are not immediately released but undergo cell division to become embryos. The embryos are released into the sea and fall onto the grafted part 40, where they germinate.

[0037] If eggs are visible on the reproductive organ bed 41, they are usually fertilized. The eggs fall from the reproductive organ bed 41 onto the grafted area 40 in about a week and implant. After that, the covering 43 is removed. This allows the eggs to settle on the grafted area 40 without being swept away by the water current and to grow.

[0038] Furthermore, in species that reproduce asexually, such as kelp and wakame, spores are formed instead of eggs. Therefore, it is not possible to visually confirm the formation of a reproductive bed as with eggs. However, if a reproductive bed has been formed, or if the algal body containing the reproductive bed is placed in the net 42, the entire structure, including the reproductive part 40, can be covered with a covering 43 that can block water flow.

[0039] In this embodiment, the genital bed 41 is placed in a net 42 to prevent it from scattering, but it may also be placed directly inside the covering 43. [Industrial applicability]

[0040] The seaweed bed creation method of the present invention is particularly useful as a method for creating seaweed beds using algae such as seaweed, which are not seed plants. [Explanation of symbols]

[0041] 10 rocks 10A Area to be created 11 Seaweed bed creation equipment 12 Covering part 13 Net 14 Inlet 15 Syringe 20 Bedrock 21 Covering sheet 21A hole 22 Weights 30 rocks 31 Covering bag 32 weight 40 Created area 41 Genital floor 42 Net 43 Covering 44 Weights

Claims

1. The area where seaweed beds are to be created is covered with a covering that can block water flow. Dispersing algal eggs or spores onto the area covered by the aforementioned covering. A method for creating seaweed beds, including the method described above.

2. The method for creating a seaweed bed according to claim 1, characterized in that the eggs or spores are dispersed through a mesh for separating the eggs or spores from each other.

3. To create a seaweed bed, to place the reproductive bed of an alga or an algal body containing the reproductive bed on the area to be created. The reproductive bed of algae or algal bodies including the reproductive bed, which are placed on the area to be created, are covered together with the area to be created by a covering that can block water flow. A method for creating seaweed beds, including the method described above.

4. The method for creating a seaweed bed according to claim 3, characterized in that the reproductive bed of the aforementioned algae or the algal body containing the reproductive bed is placed in a net and arranged on the area to be created.

5. A method for creating a seaweed bed according to any one of claims 1 to 4, comprising removing the covering after a predetermined period of time has elapsed.

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