JP6583732B2 - Method for producing savable seaweed seeds - Google Patents

Description

  The present invention eliminates a vast area due to the development of coastal areas such as landfills, etc., and also recovers algae fields such as eelgrass fields where there is a significant decrease in habitable land. The present invention relates to the preparation of a seaweed seedling for creating a field and the preservation method thereof.

  Amamo field is not only used as a spawning breeding ground for seafood, but it also absorbs nutrients from seawater and the seabed and promotes sedimentation of suspended solids. is doing. However, due to recent developments in coastal areas such as land reclamation, large areas of eelgrass have disappeared, and suitable habitats for eelgrass have diminished, causing concern about the impact on coastal ecosystems. For this reason, attempts have been made to artificially create an ammo field. There are two ways to cultivate eelgrass: collecting eel stocks and transplanting them to the planned site, and collecting seeds and sown them on the planned site.

  In order to transplant the eelgrass strain, the eelgrass strain is collected from a native eelgrass field, and each diver is transplanted to the seabed one by one in the sea. There have been proposed a method of bundling a piece of wood, a nail-like metal piece, etc., and inserting and fixing it to the seabed, or a method of wrapping the rhizome part with clay and transplanting it to the seabed for each Amamo strain (Patent Document 1). However, in such a method, it is necessary for a diver to collect and transplant each Amamo strain one by one, so it takes a lot of labor, time and cost to create a large area Amamo field. And Since it is necessary to collect the eelgrass strains to be transplanted, the impact on natural eelgrass fields is also great. In some cases, the amount of eel stock required for the planned site cannot be procured from existing natural eelgrass farms.

  On the other hand, in order to sowing seedlings as they are on the planned site, simply seeding seeds from the ship or from the shore may cause seeds to be washed away into the sea due to tides, etc. Since seeds and seedlings that have emerged are easily washed away by tidal currents etc., it is necessary to dig up the seabed and sow and cover the soil. There has also been proposed a method (Patent Document 2) in which soil mixed with sea cucumber seeds is laid on the seabed with a thickness of 3 to 5 cm or placed in a growth vessel that can be decomposed in seawater (Patent Document 2). Since it requires a lot of labor and time, a method has been proposed in which various seeding bases with measures to prevent seed loss in advance are prepared and laid (spread) from the sea to the sea floor. ing. For example, a net bag made of a corrosive material is filled with a growth base material containing sea eel seeds and laid down on the sea floor (Patent Document 3), or a mixture obtained by gelation is mixed with sea eel seeds. A method of laying the dispersed culture sandy loam on the sea floor by dumping on board (Patent Document 4), or embedding seedlings in the surface layer of a clay-like substance having a specific gravity greater than seawater, and then laying or embedding it directly on the seabed A method (Patent Document 5) has been proposed.

  It can be said that it is useful to create an eel seed sow that has been designed to prevent runoff in this way, but it is usually easy to create an eel seed sow because it is designed for a large area. It is important that the technique can be made in large quantities and is inexpensive. The conventional method (Patent Document 3) in which a net-like bag body made of a corrosive material is prepared, and then the growth base material containing sea cucumber seeds is filled in the bag body is complicated and requires a large amount of bag bodies to be prepared. There are also material costs. In the proposal of an ammo seeding base using a clay-like substance (Patent Document 5), including a method of landing on the seabed, a case where a hole is dug so as not to be affected by tidal currents and covered with the seabed soil Seed germination was observed in Japan, so it is actually necessary to bury it manually in the sea. In addition, there is a problem that a large amount of clay-like material prepared by mixing glue with powder of clay or clay mineral must be obtained at low cost, and eelgrass caused by clay runoff and collapse in natural sea areas with tides and waves. There are also concerns about seed and seedling loss. In the method (Patent Document 4) in which linseed seeds are filled in a gel-like substance, the degree of gelation is greatly influenced by the temperature and the material used, and there are problems such as low retention of sea eels in low-salt seawater. It is done. As described above, problems such as the complexity of production, the nature of the material, the cost, and whether it can be obtained in large quantities remain.

  In recent years, technologies utilizing blast furnace granulated slag and steelmaking slag, which are industrial by-products of iron manufacturing, have been proposed (Patent Documents 2, 6 and 7) as a base material for amamo fields that can be stably obtained in large quantities and at low cost. Blast furnace granulated slag has a higher specific gravity than natural sand and is excellent in stability. However, since it has a high sulfur content, there is a concern that it may adversely affect the marine sediment environment when used in large quantities in the sea. Steelmaking slag, on the other hand, contains abundant iron, phosphorus, and silica, and it can be expected to have the effect of suppressing the eel spill and the fertilization effect on the eel. In a method in which a soil composed of steel slag and dredged soil is previously mixed with sea cucumber seeds at a thickness of 3 to 5 cm, or placed in a growth vessel that can be decomposed in sea water (Patent Document 2), Seed germination and seedling growth have been confirmed. The dredged material used in this method is a construction by-product generated by dredging work, and it is also available in large quantities and at low cost. Moreover, since the solidification effect | action which steelmaking slag has is utilized, a complicated operation | work is not required only by mixing steelmaking slag and clay. However, as described above, it takes a lot of labor, time, and cost to perform the construction work on the seabed, and further laying and covering the bottom of the sea leads to the destruction of the existing ecosystem at the construction site.

  Further, as a problem for the production of the seeded body, in addition to the above-described supply and cost of materials and the complexity of production, a storage method can be mentioned. Amamo seeds are vulnerable to drying, so they must be sown immediately after the seeds are produced, and the production of the seeds is limited to the necessary area just before the preferred time of sowing. It is known that sea cucumber seeds are preserved in seawater with controlled water temperature and salinity. Amamo seeds are often stored in seawater with a salinity (Practical Salinity Unit (psu)) of about 30 to 35 at about 20 to 23 degrees or about 5 degrees or less. Sea eels release seeds in early summer, and eel seeds germinate from late autumn to early winter when the water temperature decreases. However, there is a report that the speed of germination of sea cucumber can be suppressed in an aerobic environment even at a germinable water temperature (Non-patent Document 1). Regarding salinity, it has been reported in many studies that the germination rate of seeds increases as the salinity decreases (Non-patent Document 2). Thus, there are various findings regarding germination and storage of sea cucumber seeds. However, there has been no report on the seed storage method so far, and it is necessary to devise an appropriate storage method.

Japanese Patent Publication No. 7-2063 JP 2014-100103 A JP 2001-169611 A Japanese Examined Patent Publication No. 2-59683 JP 09-205915 A JP2011-4768A JP 2006-288322 A

Brencheley JL and Probert RJ (1998) Seed germination responses to some environmental factors in the seagrass Zostera capricorni from eastern Australia.Aquatic botany 62: 177-188 Orth RJ, Harwell MC, Bailey EM, Bartholomew A, Jawad JT, Lombana AV, Moore KA, Rhode JM, Woods HE (2000) A review of issues in seagrass seed dormancy and germination: implications for conservation and restoration.Mar Ecol Prog Ser 200: 277-288

  In order to achieve the construction of a large eelgrass field that does not require a great deal of labor, time, and cost, and that has less impact on the ecosystem and the natural environment, lay a foundation that includes seedlings, seeds, and seeds of eelgrass The most convenient method is to plant the sea cucumber seeds from the sea without any such underwater work. By simply sowing from the ship or on the shore, etc., the seedlings that have settled down and seeds and seedlings are not washed away, but are maintained on the planned site, are produced without the hassle of inexpensive and inexpensive materials that can be obtained in large quantities. Therefore, it is an object of the present invention to provide a method for appropriately storing a seedling without reducing the germination ability.

In order to solve the above-mentioned problem, steelmaking slag and seabed sediment such as dredged soil, which are available in large quantities and at low cost, are used as materials for producing the eel seeds of the present invention. Taking advantage of the fact that steelmaking slag solidifies when mixed with soil etc., seagrass seeds such as sea eel seeds are attached to and retained on small chunks of mixed soil, increasing the specific gravity, and seeds and seedlings over a long period of time. A seeded body that suppresses the loss of water is easily produced without manpower. Also, in one embodiment, the seeded body produced is stored in seawater with controlled water temperature or maintained in an aerobic environment, so that the seeded body is produced as much as desired at any time. And sowing is always available. In one embodiment, when the seeded body has been preserved for a long period of time, the germination rate may be reduced even if the seeded body is seeded in the sea area at the optimal time. When seeding in the sea after promoting germination by soaking in seawater for a short period of time in low salinity (eg, about 0-15 psu) or anaerobic or optimal water temperature (eg, about 5 ° C-15 ° C) It is even more effective.
That is, the present invention is as follows.
In one aspect, the present invention provides:
[1] A seaweed seedling for seeding seaweed from the sea,
The seaweed seedling is composed of a mixed soil of steelmaking slag and seabed sediments,
The steelmaking slag is contained in the mixed soil at 50 to 95% by mass,
The mixed soil has a hardness of 500 kPa or more.
In addition, the seaweed seedling according to the present invention, in one embodiment,
[2] The seaweed seeded body of [1] above,
The steelmaking slag is decarburized slag.
In addition, the seaweed seedling according to the present invention, in one embodiment,
[3] A seaweed seeded body according to [1] or [2] above,
The seaweed is a eelgrass.
Moreover, this invention is another aspect,
[4] A method for producing a seaweed seedling for seeding seaweed from the sea,
It is a step of producing a mixed soil by mixing steelmaking slag and seabed sediment, wherein the steelmaking slag is mixed in the mixed soil at 50 to 95% by mass, and a mixed soil having a hardness of 500 kPa or more is produced. It is related with the manufacturing method including the process to do.
Moreover, this invention is another aspect,
[5] A method for preserving seaweed seeds for seeding seaweeds from the sea,
A step of attaching seaweed seeds to the surface of the seaweed seedling according to any one of the above [1] to [3] or the seaweed seedling obtained by the production method according to [4];
It is related with the preservation | save method characterized by preserving the seaweed seedling obtained by the said process in the aerobic salt water of 30-35 psu.
Moreover, this invention is another aspect,
[6] A method for creating a seaweed bed,
A step of attaching seaweed seeds to the surface of the seaweed seedling according to any one of the above [1] to [3] or the seaweed seedling obtained by the production method according to [4];
And a step of sowing a seaweed seedling obtained by the above process from the sea.
Moreover, in one embodiment, the method for constructing a seaweed bed of the present invention,
[7] A method for creating a seaweed bed,
And a step of sowing a seedling of seaweed obtained by the storage method according to [5] above from the sea.
Moreover, in one embodiment, the method for constructing a seaweed bed of the present invention,
[8] The method for constructing a seaweed bed according to [6] or [7] above,
Before the step of sowing the seaweed seedlings with the seaweed seeds on the surface thereof, the step of immersing them in fresh water or seawater at a low salinity, anaerobic or optimal germination temperature, The present invention relates to a creation method including a step of promoting later germination.

  As described above, the seaweed seeding substrate preparation method according to the present invention uses steelmaking slag as an industrial by-product and seabed sediment, for example, seabed dredging as a construction by-product, as the seed material, and the consolidation action of the steelmaking slag. It is an extremely simple and inexpensive method that requires no manual labor because a seedling of seaweed can be obtained simply by adhering and holding seaweed seeds to a small lump of mixed soil. Therefore, it can be easily applied to a large construction area.

  The obtained seaweed seedlings are relatively firmly held by the material produced by the slag consolidation action, so their holding power does not decrease due to environmental changes, and they do not contain any artifacts. Because it is a lump, it does not completely cover the ocean floor, and the impact on existing ecosystems and the natural environment is minimized.

  When the obtained seaweed seedlings are sown from a ship or shallow area, the seeds of seaweeds are attached and retained by slag, which has a higher specific gravity than seawater. Implanted. In addition, because of the specific gravity of the seagrass seeds, the seeds should be covered with the soil over time by being buried at an appropriate depth of about 2 cm in the seabed soil or being stably held in place. In addition, not only the loss of eelgrass seedlings and seedlings, but also branching (vegetative propagation) due to branching of the rhizomes is not hindered, so that a stable seagrass growth base starting from the seaweed seedling of the present invention is naturally formed.

  Seagrass seeds are attached to the mixed soil consisting of steelmaking slag, which is rich in iron, phosphorus, silica, etc., and seabed sediments rich in inorganic nitrogen, phosphorus, and silica. Germination, rooting, and growth of eelgrass strains go well. In addition, marine sediments contain organic matter that feeds benthic organisms and does not inhibit the growth of benthic organisms.

According to the present invention, the seaweed seedlings can be preserved by immersing them in seawater under controlled water temperature or in an aerobic environment, so that materials such as steel slag and dredged soil can be obtained. It becomes possible to make a seaweed seedling efficiently at a stroke regardless of the season and demand, and it can be used anywhere when necessary. When creating seaweed beds with seagrass seeds, if 30 to 40 seeds per 1 m ² are seeded, 300 to 400,000 seaweed seeds are required to create an area of 1 ha (100 m × 100 m). However, by enabling the preservation of seaweed seedlings, even if there are only small-scale production facilities, it is possible to keep making small quantities year-round as long as all materials are available. Although the present invention makes it possible to produce seaweed seeds at low cost and easily, in reality, seaweed seeds are expected to be manufactured by people and operators who can obtain seaweed seeds, materials, seawater, etc. . However, since the present invention makes it possible to preserve the seaweed seedlings after preparation, it is possible to sell and distribute the finished seaweed seedlings to a wide range of people. After that, everyone will be able to easily obtain seaweed seedlings that can only be planted in the sea area, which is expected to be widely used.

  From the above, the present invention is intended to easily achieve the restoration and creation of an artificial seagrass field in the sea area that satisfies the growth conditions of sea lions such as the underwater light environment of seagrass seeds. As a result, the formation of a seagrass field will help to improve coastal fishery productivity by purifying coastal water quality and protecting the environment and ecosystem.

Filling each square with the pre-consolidated eel seeds, divide them into appropriate sizes before consolidating, consolidate them by immersing them in seawater, and remove them after consolidating. It is a top view of the mesh frame used in order to obtain many eel seeds. FIG. 2A is a conceptual diagram of a eelgrass seeding base made of soil in which steelmaking slag and seabed sediment are mixed. Amamo seeds are attached and retained by the mixed soil of slag and dredged soil. FIG. 2B is an external view of an Amamo seedling based on a mixed soil of decarburized slag and dredged soil actually obtained by the production method of the present invention. FIG. 2C is an external view in which the surface of the eel seeds of FIG. 2B is enlarged. FIG. 2D is an external view when forming a cutlet of 1 cm × 1 cm square in an eel seedling before solidification.

The present invention provides a seaweed seedling for seeding seaweed from the sea. Here, as seaweeds, sea lions can be typically mentioned. In the description below, an ammo is described as an example.
Requirement of eelgrass seedlings An eellet seeding body consisting of particulate steelmaking slag having an average particle size of about 0.8 to 5 mm and seabed sediment. In the present specification, the sowing body refers to a mixed soil of steelmaking slag and seabed sediment, which is in a state before adhering seaweed seeds to the surface, on the surface of the sowing body, It is used by attaching seaweed seeds. In the seeded body of the present invention, since the ratio of steelmaking slag is high, seabed sediments (specifically, dredged soil, etc.) that are connected are reduced. Therefore, if the particle diameter of the steelmaking slag is too large, a space is generated in the structure, and the steelmaking slag tends to collapse. Since the size of the seeded body is, for example, about 1 cm × 1 cm, it is preferable to use a size of steelmaking slag having a particle diameter of about 5 mm or less. One eel seed sow has a size of about several centimeters, and a plurality of eel seeds are attached to the surface of the seed body. Since the seed adheres to the surface without being mixed inside the seeded body, it can germinate and grow on the seabed regardless of the hardness of the seeded body. Amamo seedlings should be used from a shipboard, shallow area, etc., and settled. It is said that the optimum depth at which seeds are buried in the seabed is about 2 cm. Therefore, the size per seed should be changed according to the hardness of the sediment in the seeding area in consideration of the sinking of the seed. Is preferred.

Forming seeds of eelgrass seeds have experimentally confirmed that the soil obtained by mixing decarburized slag, which is a type of steelmaking slag, and dredged soil is further consolidated by immersing it in seawater. The steelmaking slag used for the seaweed seeding body of the present invention is not particularly limited. However, compared with other steelmaking slags, for example, dephosphorized slag, decarburized slag tends to increase the soil hardness by mixing with dredged soil, and it is easy to make a seedling that does not collapse easily. Therefore, it is preferable to use decarburized slag as the steelmaking slag. Therefore, as a method for forming the sea cucumber seedlings, after forming the sea cucumber seedlings to an appropriate size and then immersing them in seawater to solidify, or by adding seawater in the form of a sheet or rod, or by immersing in seawater, solidify beforehand A method of cutting the lump of the eel seed sowed to an appropriate size can be applied. However, if the material is cut after consolidation, there is a risk of disintegration of the seedlings or eelgrass seeds, and therefore, a method for forming an appropriate size in an unconsolidated state is preferable. As a concrete method of forming an Amamo seedling by forming it to an appropriate size before consolidation, the mixed soil consisting of steelmaking slag and marine sediment is formed into an appropriately sized dumpling shape, and Amamo seeds are formed on the surface. After adhering, set the mixed soil in a flat container such as a tray with a suitable thickness, sow the eel seeds, and cut them to the appropriate size using a spatula, knife, lattice mold, etc. A method of post-consolidating or preparing a mesh frame 1 of an appropriate size as shown in Fig. 1 and placing the mesh frame 1 on a bottom plate (such as on a flat plate or in a tray) and mixing it in a mesh cell Put the soil with appropriate thickness, sow seeds, and submerge the mixed soil together with the mesh frame 1 and bottom plate in seawater, and then solidify it, then remove the frame to obtain many seeds of the same size at once Methods can be used. In the case where the size of the eel seeds is sufficiently small, for example, 8 mm square, the seeds of the eel are retained deep in the sown seeds, and there is little risk of inhibiting the growth of hypocotyls and larvae. Therefore, when making mixed soil, you may shape | mold, after mixing a eel seed beforehand.
In addition, it is preferable that steelmaking slag is contained in 50-95 mass% in mixed soil with a seabed sediment, and it is more preferable that it is contained at 60-80 mass%. By including the steelmaking slag at a ratio in this range, the hardness of the mixed soil can be increased, and even when the seed is sown from the sea, it can be landed on the seabed without collapsing.
Therefore, the mixed soil preferably has a certain hardness, and has a hardness of 500 kPa or more. More preferably, it has a hardness of 600 kPa or more. However, the standard of the soil hardness is a press-fit resistance value measured using a Yamanaka type soil hardness meter.

Preservation of eelgrass seeds Preservation of eelgrass seeds is performed in seawater. The salinity of seawater used for storage (practical salinity: Practical Salinity Unit (psu)) is preferably about 30 to 35 psu. The seeded body is stored in seawater kept at a temperature of 20 to 23 degrees or 5 degrees or below, seawater kept in an aerobic environment, or seawater that satisfies both conditions. Control of the water temperature includes a method in which a container containing a eel seed soaked in seawater is installed in a constant temperature culture apparatus, a method in which a eel seed is immersed in a constant temperature seawater circulating water tank, and the like. When using a method that maintains an aerobic environment, the container for soaking the seedlings in seawater should be open to keep the depth of the seawater shallow, or in an open aquarium where seawater is constantly circulating. A method of sinking the seeding body or a method of immersing the seeding body in a seawater tank aerated with air can be used. If you don't use it immediately after preparing the eel seeds, use sea water that satisfies the above-mentioned storage conditions when submerging the eel seeds in seawater and solidify them. it can.

A mixed soil obtained by adding drought soil to a decarburized slag having a particle size of 0.85 to 4.75 mm at a dry weight ratio of 7: 3 and mixing well was spread in the container 2 with a thickness of about 1 cm. There were eel seeds 3 so as to be about 3 to 4 per 1 cm ² (FIGS. 2B and C). The cut was cut to a size of about 1 cm × 1 cm in an unconsolidated state (FIG. 2D) and submerged in seawater having a salinity of about 32 for about 2 weeks. The eel seeds made of decarburized slag, dredged soil and eel seeds produced in this way can be used in the sea area as soon as they are removed from the tray. In the case of not using immediately after the preparation of eelgrass seedlings, the preparation of eelgrass seedlings is performed in a 23-degree constant temperature incubator.

DESCRIPTION OF SYMBOLS 1 ... Mesh frame 2 ... Container 3 ... Amamo seed 4 ... Mixed soil consisting of steelmaking slag and seabed sediment 5 ... Mixed soil consisting of decarburized slag and dredged soil sown with amamo seeds.

Claims (8)

A seaweed seedling for seeding seaweed from the sea,
The seaweed seedling is composed of a mixed soil of steelmaking slag and seabed sediments,
The steelmaking slag is contained in the mixed soil at 50 to 95% by mass,
The seaweed seedling, wherein the mixed soil has a hardness of 500 kPa or more. The seaweed seeded body according to claim 1,
A seaweed seeding body, wherein the steelmaking slag is decarburized slag. The seaweed seeded body according to claim 1 or 2,
A seaweed seedling, wherein the seaweed is a sea bream. A method for producing a seaweed seedling for seeding seaweed from the sea,
It is a step of producing a mixed soil by mixing steelmaking slag and seabed sediment, wherein the steelmaking slag is mixed so as to be 50 to 95% by mass in the mixed soil, and has a hardness of 500 kPa or more The manufacturing method including the process of producing soil. A method for preserving seaweed seedlings for seeding seaweeds from the sea,
A step of attaching seaweed seeds to the surface of the seaweed seedling according to any one of claims 1 to 3, or a seaweed seedling obtained by the production method according to claim 4,
A preservation method characterized by preserving the seaweed seedling obtained by the above step in seawater with an aerobic salinity of 30 to 35 psu. A method for creating a seaweed bed,
A step of attaching seaweed seeds to the surface of the seaweed seedling according to any one of claims 1 to 3, or a seaweed seedling obtained by the production method according to claim 4,
And a step of sowing a seedling of seaweed obtained by the above step from the sea. A method for creating a seaweed bed,
A creation method comprising a step of sowing a seedling of seaweed obtained by the storage method according to claim 5 from the sea. A method for creating a seaweed bed according to claim 6 and 7,
Before the step of sowing the seaweed seedlings with the seaweed seeds on the surface thereof, the step of immersing them in fresh water or seawater at a low salinity, anaerobic or optimal germination temperature, A creation method comprising a step of promoting later germination.

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