JP2020048414A - Inland aquaculture method and inland aquaculture apparatus for seaweed - Google Patents

Abstract

To enable seeds and seedlings during aquaculture to be evenly irradiated even if the size of an aquaculture tank is larger.SOLUTION: A seawater 51 for aquaculture used for cultivation of seeds and seedlings 31 in which spores of seaweed, or spore germinated body are agglomerated is poured into an aquaculture tank 111, the seeds and seedlings 31 are released into the aquaculture tank 111, a stirrer 201 floating in the water is put into the seawater 51 for aquaculture and fixed at a position, the stirrer 201 is driven to rotate a paddle blade 251 around a vertical axis, resulting in a vertical swirling flow in the aquaculture seawater 51, the aquaculture tank 111 having a circular shape as an example, and being configured to have the maximum depth of the seawater 51 for aquaculture of not exceed 600 mm. As the seawater 51 for aquaculture, for example, underground seawater, or wastewater obtained by inland aquaculture of fish and shellfish is used.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method and a device for cultivating seaweed on land for culturing seaweed on land.

  As a technique for cultivating seaweed on land, for example, Patent Literature 1 discloses preparing seeds obtained by agglomerating spores of seaweed or germinated bodies in which spores have germinated, and culturing them in an aquarium (Patent Literature) 1 paragraphs [0007] to [0009]).

  In culturing seaweed, light irradiation and oxygen supply to the seaweed are important. In this respect, Patent Document 1 describes performing aeration and stirring in a water tank (see paragraph [0010] of Patent Document 1). Running water is generated by aeration or agitation to flow the seedlings (algae agglomerates), whereby the seedlings are evenly irradiated with light and supplied with oxygen.

  Patent Literature 2 discloses a land aquaculture apparatus for seaweeds. This apparatus prepares an aquaculture tank having a U-shaped or semi-circular cross-sectional shape and a curved wall surface at the bottom, and a new aquaculture seawater is supplied from above to the aquaculture seawater stored in the aquaculture tank. It is made to flow down like a jet. Thereby, the seawater for culture in the culture tank turns along the curved wall surface, and the seawater for culture stored in the culture tank can be stirred (see paragraph [0009] of Patent Document 2).

  Patent Literature 2 further introduces the use of underground seawater and deep ocean water as aquaculture seawater (see paragraph [0001] of Literature 2).

JP 2002-176866 A JP 2012-213351 A

  In order to evenly irradiate the seedlings during the cultivation, it is necessary to ensure that all the seedlings wrap around the surface of the seawater for aquaculture. However, in a swirl relying on the flow of seawater for culture as described in Patent Literature 2, sufficient agitation is not performed as the size of the culture tank increases, and light cannot be evenly applied to the seedlings being cultured. .

  Also, the larger the aquaculture tank, the more the bulk of the curved wall at the bottom becomes necessary, so that the depth of the seawater for aquaculture must be increased. It becomes difficult to make the seedlings evenly wrap around the water surface, and it becomes more difficult to evenly irradiate the seedlings being cultured.

  Some conventional algae onshore aquaculture devices have an air tube arranged at the bottom of a culture tank and generate a swirling flow in the seawater for aquaculture by aeration using air ejected from the air tube. According to such a structure, a more aggressive generation and control of a swirling flow is possible. It is assumed that the effect of stirring seawater can be enhanced.

  However, as the size of the culture tank increases, the swirling flow is less likely to occur unless the depth of the culture seawater is increased. For this reason, similarly to the one described in Patent Literature 1, it becomes difficult to evenly wrap the seedlings near the water surface by that amount, and it becomes impossible to uniformly irradiate the seedlings being cultured with light.

  An object of the present invention is to make it possible to evenly irradiate seeds and seedlings being cultured even if the size of the culture tank is increased.

  The method of onshore cultivation of seaweeds of the present invention is to inject aquaculture seawater for use in culturing seeds in which spores or spores of seaweed are germinated into a cultivated seedling, and release the seedlings into the cultivation tank, A stirrer having webbing blades rotating around a vertical axis and floating in water is thrown into the seawater for aquaculture and the position is fixed, and the agitator is driven by a drive source to rotate the webbing blades to rotate the aquaculture. Creates a vertical swirl in seawater.

  The marine algae terrestrial aquaculture apparatus of the present invention is a cultivation tank for storing aquaculture seawater used for culturing seeds in which spores or spores of seaweed are germinated and spores are agglomerated. A web impeller that generates a swirling flow, a drive unit that drives and rotates the web impeller, and a stirrer that is put into the seawater for culture and floats, and on the seawater for culture housed in the culture tank And a fixing section for fixing the position of the stirrer.

  According to the present invention, a swirling flow can be generated even in the seawater for aquaculture having a shallow water depth by the rotation of the web blades, so that the seeds and seedlings can be evenly wrapped near the water surface and can be uniformly irradiated with light.

BRIEF DESCRIPTION OF THE DRAWINGS As one Embodiment, the perspective view which shows an example of the culture facility for implementing the land culture method of a seaweed. The schematic diagram which shows an example of the procedure of the land culture method of a seaweed. The schematic diagram which shows another example of the procedure of the land culture method of a seaweed. The schematic diagram which shows the process of producing a seedling. FIG. 2 is a plan view showing the stirrer according to the first embodiment. The side view. The top view showing the stirrer of a second embodiment. The side view. (A) is a first-stage culture process using a 1-meter-diameter culture tank, (b) is a second-stage culture process using a 2-meter-diameter culture tank, and (c) is a 5-meter-diameter culture tank. FIG. 4D is a schematic diagram showing a third-stage culture process using a culture tank having a diameter of 10 meters, respectively. The perspective view which shows the state in which the stirrer floats in the culture tank of 10 meters in diameter.

An embodiment will be described with reference to the drawings. This embodiment is an example of application to an aquaculture facility 11 for aquaculture of seaweed on land. The description of the present embodiment will be made in accordance with the following items.
[Aquaculture facilities]
[Aquaculture system]
[Onshore farming method]
1. 1. Production of seeds and seedlings Release of seedlings 3. Irrigation 4. Stirrer installation
(1) Structure of stirrer
(2) Injection of stirrer and fixing of position Operation of Stirrer [Other Embodiments and Modifications]

[Aquaculture facilities]
As shown in FIG. 1, the aquaculture facility 11 of the present embodiment is installed on a coast 13 adjacent to the sea 12 and includes a plurality of on-land aquaculture devices 101. Each land-based aquaculture apparatus 101 mainly includes a culture tank 111 for accommodating seawater for culture 51 used for culturing the seedlings 31 of seaweed, and includes four types of culture tanks 111 having different sizes (FIGS. 2 to 2). 4, see FIG. 9). There are four types, 1 meter, 2 meters, 5 meters, and 10 meters in diameter, and the culture tanks 111 of any size are perfectly circular (see FIGS. 9A to 9D).

  In the aquaculture facility 11, the nine on the left side shown in FIG. 1 have a diameter of 10 meters, the adjacent row and one on the right side have a diameter of 5 meters, and the right side has seven rows in a row of 2 meters, and beyond. A row of eight rows is a culture tank 111 having a diameter of 1 meter. For convenience of explanation, the culture tank 111 having a diameter of 1 meter is a culture tank 111a, the culture tank 111 having a diameter of 2 meters is a culture tank 111b, the culture tank 111 having a diameter of 5 meters is a culture tank 111c, and the culture tank 111 having a diameter of 10 meters is a culture tank. Call it 111d.

[Aquaculture system]
As shown in FIG. 2, the aquaculture system using the onshore aquaculture device 101 of the present embodiment takes advantage of the fact that it is installed on the coast 13 adjacent to the sea 12, and uses clean underground seawater as the aquaculture seawater 51. Use. That is, underground seawater of about 20 meters underground is taken and injected into the aquaculture tank 111 as aquaculture seawater 51. The aquaculture seawater 51 is injected from the water supply port 112.

  Underground seawater is less dependent on temperature and is kept at around 20 ° C throughout the year. This temperature is a temperature suitable for culturing seaweed. In addition, the groundwater may contain abundant nutrients necessary for the growth of seeds 31.

  What is important when injecting the culture seawater 51 into the culture tank 111 is the depth of the water. In the present embodiment, the maximum water depth of any of the four types of culture tanks 111 (111a, 111b, 111c, 111d) having different sizes is set not to exceed 600 mm. More specifically, the water depth is set so as to be 300 mm at a shallow position and 400 mm at a deepest position. The setting of the water depth is performed by the height of the drain port 113. That is, by providing the drainage port 113 at a position with a water depth of 300 to 400 mm, the further supplied seawater for aquaculture 51 flows outside from the drainage port 113, and the water depth in the culture tank 111 is maintained at 300 to 400 mm. That is.

  The reason why there is a difference of 100 mm in water depth is that the culture tanks 111 of any size are installed at an angle. The reason for tilting is for irrigation. This will be described in detail later.

  As another embodiment, as shown in FIG. 3, clean underground seawater may be used once for onshore cultivation of fish and shellfish, crustaceans, etc., and the wastewater may be used as seawater for cultivation 51. Thus, nutrient-rich seawater for culture 51 can be obtained.

[Onshore farming method]
The onshore aquaculture method of the present embodiment is executed by the following steps.
1. Production of Seedlings As shown in FIG. 4, in order to produce seedlings 31, mother algae 32 are first collected from the sea 12, and spores 33 are released from the mother algae 32. Then, the spores 33 or the germinated body (not shown) in which the spores 33 germinated are agglomerated, and this is used as a seedling 31. Agglomeration of the spores 33 or the germinated material in which the spores 33 have germinated can be performed, for example, by the method disclosed in Patent Document 1. According to this method, seaweed spores are seeded on a plate at a density of 10 ⁴ or more per cm ² and cultured. A body mass is formed, and then the spore mass or the germinated mass is removed from the plate to obtain a seedling.

2. Release of seeds and seedlings The culture system according to the present embodiment releases the seeds and seedlings 31 thus obtained into the seawater for culture 51 stored in the culture tank 111. Seedlings 31 grow in seawater 51 for aquaculture.

  At this time, what is necessary for the growth of the seedling 31 is uniform light irradiation and oxygen supply to the seedling 31. In the present embodiment, these are realized by the stirrer 201. This will be described later.

3. The irrigated seedling 31 grows about 5 times in size in about 4 to 5 days. Therefore, as shown in FIGS. 9A to 9D, in the present embodiment, the size of the culture tank 111 is gradually increased from the first stage to the fourth stage in accordance with the growth of the seedling 31. Go. When the fourth stage of the aquaculture process is completed, the aquaculture of the seed and seedling 31 is also completed.

  The timing of transition from one stage to the next is about one week. That is, a certain stage of the aquaculture process is performed, and after one week, the process proceeds to the next stage of the aquaculture process.

As shown in FIG. 9A, in the first stage of the culture process, a culture tank 111a having a diameter of 1 meter and 0.8 m ² is used. At this time, the aquaculture seawater 51 is stirred by, for example, an air pump (not shown) without using the stirrer 201.

As shown in FIG. 9B, in the second stage of the aquaculture process, an aquaculture tank 111b having a diameter of 2 meters and 3.1 m ² is used. At this time, the aquaculture seawater 51 is stirred by, for example, an air pump (not shown) without using the stirrer 201.

As shown in FIG. 9C, in the third stage of the aquaculture process, an aquaculture tank 111c having a diameter of 5 meters and a size of 19.6 m ² is used. The aquaculture seawater 51 is stirred by the stirrer 201.

As shown in FIG. 9D, in the fourth stage of the aquaculture process, an aquaculture tank 111d having a diameter of 10 meters and a size of 78.5 m ² is used. The aquaculture seawater 51 is stirred by the stirrer 201.

  To irrigate, with the seedlings 31 temporarily evacuated, a stopper (not shown) provided at the bottom of the culture tank 111 (111a, 111b, 111c, 111d) is opened, and the culture seawater 51 is drained. At this time, since the aquaculture tank 111 is installed with an inclination, it is possible to drain all of the aquaculture seawater 51 by setting the position of the stopper at the lowest position. After draining, the seawater for culture 51 is again poured into the culture tank 111 from the water supply port 112.

  In this embodiment, since the culture tank 111 has a perfect circular shape, more seawater for culture 51 can be stored for a length determined by the diameter of the culture tank 111. In a generally used rectangular culture tank, the length ratio between the long side and the short side is not close to 1: 1 and the length of the long side is extremely long with respect to the short side. . Due to such a shape, in the culture tank 111 of the present embodiment, for example, a rectangular culture tank capable of storing the seawater 51 for aquaculture of the same size as the culture tank 111d has a length that is incomparable with the diameter of the culture tank 111d. The length of the side becomes longer. For this reason, when the culture tank is tilted for drainage, a large load is applied to the long side portion. Therefore, the rectangular culture tank must be formed of a strong material such as concrete or fiber reinforced plastic (FRP). The culture tank 111 of this embodiment, which is shorter in length than this point, may have lower rigidity than a rectangular culture tank, and can be formed of an inexpensive material such as polypropylene (PP).

4. Installation of Stirrer As described above, in the third and fourth aquaculture steps, the aquaculture seawater 51 is stirred by the stirrer 201 (see FIGS. 9C and 9D). Therefore, in the third and fourth aquaculture processes, the agitator 201 is installed in the aquaculture seawater 51 housed in the aquaculture tank 111.
(1) Structure of Stirrer Two embodiments will be described.

  5 and 6 show a first embodiment of the stirrer 201. FIG. The stirrer 201 has a structure in which a balancer 231 is rotatably mounted between a lower housing 211 and an upper housing 212 each having a cylindrical shape, and a web blade 251 is mounted on the balancer 231.

  The lower housing 211 has a built-in motor (not shown) serving as a drive source for the web blades 251. The upper housing 212 contains a motor drive circuit. The motor is housed in the lower housing 211 with the rotating shaft directed vertically, and connects the rotating shaft to the balancer 231. The rotation of the motor is decelerated by the reduction mechanism and transmitted to the balancer 231, and transmitted to the web blade 251 via the balancer 231.

  As an example, the web blade 251 rotates at a rotation speed of about one rotation / 20 seconds.

  Each part is sealed with a seal (not shown). The seal keeps the motor housed in the lower housing 211 and the drive circuit housed in the upper housing 212 in a watertight state.

  A branch pipe 232 branched into three branches at an angle of 120 degrees is connected to the balancer 231. The web blade 251 includes an arm 252 extending radially from a tip end of each of the three branch pipes 232, and a paddle 253 extends downward from a lower end of the arm 252. Therefore, the web blades 251 rotate with the rotation of the balancer 231 and stir the fluid.

  The balancer 231 also creates buoyancy for water. The stirrer 201 can float on the water by the buoyancy of the balancer 231.

  The stirrer 201 has two connecting rods 271 extending from the upper housing 212 in the horizontal direction. These connecting rods 271 are used to connect a rope 301 for fixing the position of the stirrer 201, and have a ring 272 at the distal end. Rope 301 can be tied to ring 272.

  The stirrer 201 of the present embodiment is suitable for use in the third stage aquaculture process. The third stage of the culture process uses a culture tank 111c having a diameter of 5 meters. In the stirrer 201 of the present embodiment, the length of the arm 252 is set according to the culture tank 111c having a diameter of 5 meters. However, it is not unsuitable for use in the fourth stage aquaculture process. When used in the fourth stage of the aquaculture process, the length of the arm 252 may be increased in accordance with the aquaculture tank 111d having a diameter of 10 meters.

  7 and 8 show a second embodiment of the stirrer 201. This stirrer 201 has basically the same structure as the first stirrer 201. The difference is the angle and number of paddles 253. In addition, the length of the arm 252 is longer than that of the stirrer 201 of the first embodiment, and this is a culture tank 111d having a diameter of 10 meters so as to be suitable for use in the fourth culture process. It is the result according to. The stirrer 201 of the second embodiment can also be adapted for use in the third stage aquaculture process using the aquaculture tank 111c having a diameter of 5 meters by shortening the length of the arm 252.

  The stirrer 201 of the present embodiment is essentially different from the stirrer 201 of the first embodiment in the angle and the number of the paddles 253 as described above. The paddles 253 are mounted two on each arm 252 at an angle to the radial direction. The angle inclined with respect to the radiation direction is, for example, 45 degrees. However, the angle need not be 45 degrees, but may be another angle.

  Two embodiments of the stirrer 201 have been described. In any of the agitators 201, if the motor is started by the drive circuit, the web blades 251 rotate. The web blades 251 stir the aquaculture seawater 51 so as to create water flows in the vertical and horizontal directions by the action of the paddle 253.

(2) Injection of Stirrer and Position Fixation The stirrer 201 is introduced into the seawater for culture 51 housed in the culture tank 111. At this time, the worker attaches the rope 301 to the ring 272 of the connecting rod 271 of the stirrer 201 and throws the stirrer 201 into the seawater 51 for aquaculture. Then, the free end side of the rope 301 is attached to the pile 302 struck on the ground G at a position near the periphery of the culture tank 111. Thus, the position of the stirrer 201 is fixed in the culture tank 111. At this time, the stirrer 201 is positioned so as to be fixed at the center of the culture tank 111.

5. Operation of Stirrer When the stirrer 201 is put into the seawater for culture 51 and the position is fixed, the motor is started to rotate the web blades 251. As a result, vertical and horizontal swirling flows are generated in the aquaculture seawater 51, and stirring is performed. Since the stirring is performed by the swirling flow in the vertical direction and the horizontal direction, the aquaculture seawater 51 staying downward rises toward the water surface. explain in detail.

  In each of the stirrers 201 of the above two embodiments, the paddle 253 creates a vertical water flow and a horizontal water flow by the rotation of the web blades 251 to stir the seawater 51 for aquaculture.

  The vertical water flow is generated within the horizontal projection plane of the web blades 251 and goes to the bottom of the culture tank 111. The water flow directed toward the bottom collides with the bottom, and returns upward, thereby stirring the seawater 51 for culture. The movement of the seedling 31 stagnating at the bottom of the aquaculture tank 111 mainly in the horizontal projection plane of the web blades 251 is activated by this stirring action. The seed and seedling 31 whose movement has been activated rises and floats toward the surface of the seawater 51 for aquaculture.

  The horizontal water flow is generated near the water surface right beside the paddle 253 and goes toward the inner wall of the culture tank 111. The water flow directed to the inner wall collides with the inner wall, wraps around the bottom of the culture tank 111, and returns laterally along the bottom to agitate the culture seawater 51. By this stirring action, the movement of the seedling 31 stagnating at the bottom of the aquaculture tank 111 mainly at a position outside the horizontal projection plane of the web blades 251 is activated. The seed and seedling 31 whose movement has been activated rises and floats toward the surface of the seawater 51 for aquaculture.

  Seedlings 31 released into aquaculture seawater 51 change position by agitation of aquaculture seawater 51, and go around the water surface or near the water surface evenly. Therefore, light irradiation with sunlight can be uniformly performed on all the seedlings 31, and it is possible to promote the successful growth of the seedlings 31.

  What is important at this time is that the stirrer 201 stirs the culture seawater 51 by generating a vertical swirling flow. By using such a stirring principle, even if the size of the culture tank 111 is increased, the culture seawater located within the horizontal projection plane of the web blades 251 is maintained while maintaining a shallow water depth of about 300 to 400 mm. 51 can be sufficiently stirred. As a result, by setting the depth of the seawater for aquaculture 51 to a shallow depth of about 300 to 400 mm, the seawater for aquaculture 51 located at a position deviating from the horizontal projection plane of the web blades 251 is also laterally rotated by the stirrer 201. It can be sufficiently stirred by the flow.

  Another important thing is that the culture tank 111 has a perfect circular shape. As described above, the horizontal water flow generated by the paddle 253 by the rotation of the web blades 251 mainly activates the movement of the seedlings 31 stagnating at the bottom of the culture tank 111 at a position outside the horizontal projection plane of the web blades 251. Become At this time, if the culture tank 111 has a perfect circular shape, even in a region near the inner wall of the culture tank 111 that is out of the horizontal projection plane of the web blades 251, it is easy to cause the seawater 51 for culture to uniformly agitate. In particular, if the stirrer 201 is fixed at the center position of the culture tank 111 as in the present embodiment, it is easier to produce a uniform stirring action on the culture seawater 51 in a region near the inner wall of the culture tank 111. Become. As a result, the seeds and seeds 31 discharged into the seawater for aquaculture 51 can be more evenly wrapped around the water surface or near the water surface, and it is possible to encourage the seeds and seeds 31 to grow smoothly.

  Due to the above-described operation of the culture tank 111 having the perfect circular shape, the culture tank 111 is not a perfect circle, but may be, for example, an elliptical shape or a polygonal shape. Of course, it is desirable that the shape is an elliptical shape or a polygonal shape closer to a perfect circular shape. However, this is because the uniformity of the stirring action generated in the aquaculture seawater 51 at a position outside the horizontal projection plane of the web blades 251. The degree of deformation from a perfect circular shape may be determined by a trade-off with the above. In the case of a polygonal shape, it is desirable that the angle between two adjacent sides is an obtuse angle.

  The action brought about by the agitation of the seawater for aquaculture 51 activates the movement of the seed and seedlings 31 and raises the seed and seedlings 31 stagnating at the bottom of the aquaculture tank 111 toward the water surface, so that the seeds and seeds 31 run around the water surface or near the water surface evenly. It doesn't stop there. By agitating the seawater 51 for aquaculture, oxygen supply and nutrient supply to the seedlings 31 are evenly performed, and from this aspect, it is possible to promote the successful growth of the seedlings 31.

  According to the on-shore aquaculture method using the on-shore aquaculture device 101 of the present embodiment, the successful growth of the seed and seedling 31 is promoted by other factors.

  One of the other factors is that underground seawater is used as the culture seawater 51. As described above, the optimal temperature for growing the seedling 31 is around 20 ° C. The temperature of the underground seawater used as the seawater for aquaculture 51 is maintained at a temperature of about 20 ° C. throughout the year, so that the smooth growth of the seeds 31 is promoted. In addition, the underground seawater is rich in nutrients necessary for raising the seeds and seedlings 31, and from this aspect also, the smooth growth of the seeds and seedlings 31 is promoted.

  Another factor is the rotation speed of the web blades 251. As described above, the web blade 251 is driven to rotate at a relatively low speed of about one rotation / 20 seconds. The higher the speed, the easier it is for the seedlings 31 to gather at the rotation center of the web blades 251, that is, immediately below the stirrer 201. On the other hand, in the present embodiment, since the rotation speed of the web blades 251 is set to a relatively low speed, the seeds and seedlings 31 can move uniformly in the culture tank 111 and perform more uniform light irradiation. It becomes possible.

The various factors described above are accumulated, and according to the present embodiment, it is possible to promote the successful growth of the seed and seedling 31.
[Other Embodiments and Modifications]

  Upon implementation, not only the above-described embodiment, but also other embodiments may be adopted.

  For example, the position of the stirrer 201 may be fixed not only by the rope 301 but also by various alternative means such as a wire or a fixed link.

  In other implementations, all modifications and changes are allowed.

DESCRIPTION OF SYMBOLS 11 Culture facility 12 Sea 13 Coastal area 31 Seedling 32 Mother algae 51 Seawater for culture 101 Land culture equipment 111 Culture tank 111a Culture tank (culture tank of 1 meter in diameter)
111b Culture tank (culture tank with a diameter of 2 meters)
111c culture tank (culture tank with a diameter of 5 meters)
111d culture tank (culture tank with a diameter of 10 meters)
112 Water supply port 113 Drainage port 201 Stirrer 211 Lower housing 212 Upper housing 231 Balancer 232 Branch pipe 251 Web blade 252 Arm 253 Paddle 271 Connecting rod 272 Ring 301 Rope 302 Pile G Ground

Claims (10)

Injecting seawater for culture used for cultivation of seeds and seedlings in which spores or spores of seaweed have germinated are agglomerated,
Release the seeds and seedlings into the culture tank,
A stirrer having floating blades rotating around a vertical axis and floating in water is thrown into the aquaculture seawater and fixed in position,
By driving the stirrer by a drive source to rotate the web blades, to generate a vertical swirling flow in the culture seawater,
A method of cultivating marine algae on land, characterized in that: The web blade including an arm extending in the radial direction from the center of rotation and a paddle extending in a vertical direction provided on the arm at an angle inclined with respect to the radial direction is used.
The method of cultivating seaweed on land according to claim 1, wherein: Using the circular culture tank,
The terrestrial cultivation method of seaweed according to claim 1 or 2, characterized in that: The angle between the two sides adjacent to each other is an obtuse angle, the polygonal culture tank is used,
The terrestrial cultivation method of seaweed according to claim 1 or 2, characterized in that: The stirrer is fixed at the center of the culture tank,
The method of cultivating marine algae on land according to any one of claims 1 to 4, wherein: When throwing the seawater for aquaculture into the aquaculture tank, the maximum water depth should not exceed 600 mm,
The method of cultivating seaweed on land according to any one of claims 1 to 5, wherein: Using underground seawater as the aquaculture seawater,
The method of cultivating seaweed on land according to any one of claims 1 to 6, wherein: Using wastewater obtained by cultivating seafood and the like on land as the seawater for aquaculture,
The method of cultivating seaweed on land according to any one of claims 1 to 7, wherein: A culture tank containing seawater for aquaculture used for cultivation of seeds and seedlings in which spores or spores of seaweed are germinated are aggregated,
A web impeller that generates a vertical swirling flow by rotation about a vertical axis, and a drive unit that drives and rotates the web impeller, and a stirrer that is thrown into the culture seawater and floats,
A fixing unit that fixes the position of the stirrer on the culture seawater stored in the culture tank,
A land aquaculture apparatus for seaweeds comprising: The web blade is
An arm extending radially from the center of rotation;
A vertically extending paddle provided on the arm at an angle to the radial direction,
The marine algae terrestrial aquaculture apparatus according to claim 9, comprising: