Ropes for seaweed cultivation, seaweed cultivation facilities, and seaweed cultivation methods

Abstract

The present invention provides a rope for seaweed cultivation, a seaweed cultivation facility, and a seaweed cultivation method that can sustainably promote the growth of the entire seaweed species being cultivated. [Solution] The seaweed cultivation rope 1A comprises a cultivation rope 5 to which seaweed is attached, a wire 6 attached to the cultivation rope 5, and a magnesium rod 7 supported by the cultivation rope 5, made of a metal material with a higher ionization tendency than the wire 6, electrically connected to the wire 6, and supplying electrons to the wire 6 when placed in the sea.

Description

Technical Field

[0001] The present invention relates to a rope for seaweed cultivation, a seaweed cultivation facility, and a seaweed cultivation method.

Background Art

[0002] In recent years, due to environmental changes such as the rise in seawater temperature, the aquaculture production volume of seaweed has been on a decreasing trend, which has become a factor for fishermen to leave. Therefore, the development of aquaculture techniques to effectively promote the growth of seaweed has been underway. For example, Patent Document 1 discloses an aquaculture method using a rope for seaweed cultivation filled with fertilizer in its internal hollow part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the aquaculture method of Patent Document 1, since the rope for seaweed cultivation filled with fertilizer is floated on the sea surface, it is difficult to distribute the fertilizer eluted on the sea surface to the entire seaweed in the sea, and there is a problem that the growth of a part of the seaweed is delayed. In addition, there is also a limit to the amount of fertilizer that can be accommodated in the rope. When all the fertilizer elutes from the rope, replacement is required. On the contrary, when the concentration of the fertilizer is high, it may also cause red tides.

[0005] The present invention has been made based on such a background, and an object thereof is to provide a rope for seaweed cultivation, a seaweed cultivation facility, and a seaweed cultivation method capable of continuously promoting the growth of the entire seaweed to be cultivated.

Means for Solving the Problems

[0006] In order to achieve the above object, the rope for seaweed cultivation according to the present invention is A cultivation rope with seaweed attached, The cathode attached to the aforementioned training rope, A sacrificial anode is supported by the aforementioned training rope, is made of a metallic material with a higher ionization tendency than the cathode, is electrically connected to the cathode, and supplies electrons to the wire when placed in the sea. It is equipped with. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a rope for seaweed cultivation, a seaweed cultivation facility, and a seaweed cultivation method that can sustainably promote the growth of the entire seaweed being cultivated. [Brief explanation of the drawing]

[0008] [Figure 1] This is a front view showing the configuration of a seaweed cultivation facility according to an embodiment of the present invention. [Figure 2] This is a front view showing the relationship between the cultivation rope and the wire in a seaweed cultivation rope according to an embodiment of the present invention. [Figure 3] This figure shows a magnesium rod covered with a protective cover in a rope for seaweed cultivation according to an embodiment of the present invention. [Figure 4] This is a photograph showing the external appearance of the prototype in the embodiment. [Figure 5] This is a photograph showing the appearance of kelp cultivated using the prototype machine described in the example. [Modes for carrying out the invention]

[0009] Hereinafter, a rope for seaweed cultivation, a seaweed cultivation facility, and a seaweed cultivation method according to embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or equivalent parts are denoted by the same reference numerals.

[0010] In the embodiments, "seaweed attachment" is not limited to the attachment of seaweed sporophytes, but also includes the attachment of any of the seaweed's zoospores, gametophytes, or fertilized eggs. The sporophytes include young sporophytes and mature sporophytes. Furthermore, this is not limited to direct attachment of these to the object, but also includes the planting of seedling filaments to which these are attached into the object.

[0011] The seaweed cultivation facility according to this embodiment is a device that promotes the growth of seaweed attached to a cultivation rope by attracting minerals from seawater to the cultivation rope while the cultivation rope, to which seaweed is attached, is placed in the sea. The seaweed can be of any type, but for example, kelp, wakame, mozuku, and nori are preferred, with kelp, especially Makonbu, being preferred. Seedling threads to which seaweed zoospores are attached are preferably planted on the cultivation rope. The seedling threads are, for example, Cremona twisted threads with a diameter of 2 mm, to which seaweed zoospores are attached by being pre-soaked in a liquid containing seaweed zoospores.

[0012] In the seaweed cultivation facility according to this embodiment, an iron wire is wrapped around a cultivation rope, a magnesium rod is connected to the end of the cultivation rope, and the wire and magnesium rod are electrically connected. As a result of diligent research by the inventors, it was found that by applying cathodic protection technology and generating a potential difference between the magnesium rod (sacrificial anode) and the iron wire (cathode) in the sea, seaweed growth is promoted, and a yield of 2 to 3 times that of conventional cultivation methods can be achieved.

[0013] To explain the mechanism, magnesium and its alloys are metals with a higher ionization tendency than iron wire. Therefore, when a magnesium rod and an iron wire are electrically connected and immersed in seawater, which is the electrolyte, a battery is created with the magnesium rod as the anode and the iron wire as the cathode, and magnesium ions (Mg) are released from the magnesium rod. 2+ The magnesium gradually dissolves. This creates a potential difference between the magnesium rod and the wire, supplying electrons from the magnesium rod to the wire, and simultaneously causing a corrosion-preventive current to flow from the magnesium rod through the seawater to the wire.

[0014] When electrons are supplied to the wire, minerals in the seawater, such as calcium ions, magnesium ions, and iron ions, are attracted to the wire to combine with the electrons, and these minerals are continuously supplied to the area around the kelp attached to the cultivation rope. At this time, the wire is continuously supplied with electrons from the magnesium rod, so it does not rust due to reduction and functions as a cathode as long as the magnesium rod is present.

[0015] Next, the configuration of the seaweed cultivation facility 1 according to the embodiment will be described with reference to Figures 1 to 3. As shown in Figure 1, the seaweed cultivation facility 1 comprises a plurality of floats 2 that can be floated on the surface of the sea, a main rope 3 that extends along the surface of the sea with both ends connected to each float 2, a plurality of anchor ropes 4 with one end connected to each float and the other end fixed to the seabed, a plurality of cultivation ropes 5 that are supported at different positions on the main rope 3 at intervals from each other and suspended toward the seabed by the main rope 3, an iron wire 6 wrapped around each cultivation rope 5, and a magnesium rod 7 that is suspended by the cultivation ropes 5 and electrically connected to the wire 6, supplying electrons toward the wire 6 while immersed in seawater.

[0016] The cultivation rope 5, wire 6, and magnesium rod 7 of the seaweed cultivation facility 1 constitute the seaweed cultivation rope 1A. Furthermore, the float 2, main rope 3, and anchor rope 4 are examples of mooring means installed in coastal waters to suspend the seaweed cultivation rope 1A in the sea. The components of the seaweed cultivation facility 1 are described below.

[0017] Floats 2 are, for example, buoys used as markers. Floats 2 are provided with a through-hole through which the main rope 3 can be inserted, and the main rope 3 is tied to the through-hole. The size and number of floats 2 used in the seaweed cultivation facility 1 should be determined considering the weight of the seaweed cultivation facility 1 and the seaweed, as well as the strength of the ocean current. As time passes after the installation of the seaweed cultivation facility 1, various organisms other than seaweed will attach to the seaweed as it grows, so depending on how much the seaweed cultivation facility 1 sinks, additional floats 2 may be added during cultivation.

[0018] The main line 3 has a strength such that it is not cut by external forces such as ocean currents or floating objects, and for example, it is a three-strand rope made of polypropylene. The cultivation ropes 5 are connected to the main line 3 at intervals in the longitudinal direction of the main line 3. The interval between adjacent cultivation ropes 5 is, for example, within the range of 1 m to 5 m, preferably 2 m.

[0019] <000~094>The anchor rope 4 positions the float 2 and the main line 3 so that they are not carried away by ocean currents. The anchor rope 4 is fixed to the seabed by an anchor 4a driven into the seabed. Note that the anchor rope 4 may be fixed to the seabed by means other than the anchor 4a, for example, using sandbags or blocks.

[0020] The cultivation rope 5 is a rope formed such that seaweed seedling threads are planted and the germinated seaweed can take root against ocean currents. The cultivation rope 5 is twisted, and seaweed seedling threads are planted between the twists.

[0021] The cultivation rope 5 has a strength such that it is not cut by external forces such as ocean currents or floating objects. The cultivation rope 5 may be a rope having the same or equivalent structure as the main line 3, and for example, it is a three-strand rope made of polypropylene. The diameter of the cultivation rope 5 may be set in consideration of the required strength, and it may be the same as or thinner than the main line 3. Specifically, the diameter of the cultivation rope 5 is, for example, within the range of 5 mm to 20 mm, preferably within the range of 10 mm to 15 mm, and more preferably 12 mm. The length of the cultivation rope 5 may be set in consideration of the depth of the seabed and the strength of the ocean current, and for example, it is within the range of 1 m to 10 m, preferably within the range of 2 m to 6 m, and more preferably 4 m.

[0022] <0000^03>The training rope 5, the main rope 3, and the magnesium rod 7 are connected using a cross rope 5a. The cross rope 5a is an example of a connecting rope that connects the training rope 5, the main rope 3, and the magnesium rod 7. The cross rope 5a is also called an eight-strand rope and is a rope made by twisting together a total of four sets of two strands, and has the characteristics of being flexible and resistant to twisting. The diameter of the cross rope 5a is set considering strength and ease of tying, and is, for example, in the range of 5 mm to 10 mm, preferably 7 mm.

[0023] The wire 6 is wrapable around the training rope 5 and is made of iron, such as carbon steel or alloy steel. As shown in Figure 2, the wire 6 is wrapped around the twists of the training rope 5, and in this state, the training rope 5 and the wire 6 are tightened together using a cable tie 6a. Because the wire 6 is spirally wrapped around the training rope 5, when the wire 6 becomes the cathode in the sea, it can attract cations from the seawater to the entire training rope 5.

[0024] Returning to Figure 1, the magnesium rod 7 is a rod made of magnesium or a magnesium alloy. The magnesium rod 7 is made of a metal with a higher ionization tendency than the metal material of the wire 6 and is an example of a sacrificial anode that supplies electrons to the electrically connected wire 6. The dimensions of the magnesium rod 7 should be set considering the persistence of the anticorrosion current in the sea, the current density, and the role of the magnesium rod 7 as a weight. The diameter of the magnesium rod 7 is, for example, in the range of 10 mm to 50 mm, and its length is, for example, in the range of 200 mm to 800 mm.

[0025] As shown in Figure 3, the magnesium rod 7 has a circular cross-section and is tapered at both ends. A ring member 7a is welded to one end, through which the cross rope 5a and wire 6 can be inserted. The cross rope 5a is inserted through the ring member 7a and tied to the training rope 5, thereby mechanically connecting the training rope 5 and the magnesium rod 7. The wire 6 is also inserted through the ring member 7a and tied to it, thereby electrically connecting the wire 6 and the magnesium rod 7. The above describes the configuration of seaweed cultivation facility 1.

[0026] Because the seaweed cultivation facility 1 has the above configuration, electrons are supplied from the magnesium rod 7 to the wire 6, and the wire 6, which functions as a cathode, attracts minerals from the seawater around the cultivation rope 5. As a result, the growth of seaweed planted on the cultivation rope 5 is promoted. It takes a long time for the magnesium rod 7 to completely dissolve, and since the minerals in the seawater are inexhaustible, minerals are supplied to the area around the cultivation rope 5 semi-permanently. In addition, since the magnesium rod 7 is connected to the end of the cultivation rope 5, and the cultivation rope 5 is connected to the main rope 3 with the magnesium rod 7 on the underside, the magnesium rod 7 also functions as a weight, making it less likely for adjacent cultivation ropes 5 to become entangled.

[0027] Next, the manufacturing process for the seaweed cultivation facility 1 according to the embodiment will be explained. First, wrap a wire 6 around each training rope 5 to secure it so that it does not come off. Specifically, wrap the wire 6 spirally between the twists of the training rope 5, and then secure the training rope 5 and the wire 6 together with a cable tie 6a to prevent them from coming apart.

[0028] Next, the cross ropes 5a are used to mechanically connect each training rope 5 to the magnesium rod 7, and the wire 6 is electrically connected to the magnesium rod 7. Specifically, the cross rope 5a is passed through the ring member 7a of the magnesium rod 7, and the cross rope 5a is tied to one end of the training rope 5. The wire 6 is also inserted through the ring member 7a and tied to it.

[0029] Next, multiple training ropes 5 are connected to the main rope 3 at intervals along the longitudinal direction of the main rope 3. Specifically, one end of the cross rope 5a is tied to the other end of the training rope 5, and then the other end of the cross rope 5a is tied to the main rope 3.

[0030] Next, attach floats 2 to both ends of the main rope 3, and attach anchor ropes 4 to each float 2. Specifically, pass the main rope 3 through the through hole of the float 2 and tie it, and pass the anchor ropes 4 through the other through hole of the float 2 and tie them. The above is the process for manufacturing the seaweed cultivation facility 1.

[0031] Furthermore, during the manufacturing of the seaweed cultivation facility 1, a cylindrical protective cover 7b is detachably attached to the magnesium rod 7, as shown in Figure 3. The protective cover 7b is attached to prevent the magnesium rod 7 from igniting due to a strong impact, and is removed before the seaweed cultivation facility 1 is installed in the sea.

[0032] Next, the flow of the seaweed cultivation method using the seaweed cultivation facility 1 according to the embodiment will be described. Hereafter, it will be assumed that seaweed zoospores are attached to the seaweed seed filaments.

[0033] First, on land, the seaweed seedling threads are attached to each cultivation rope 5 of the seaweed cultivation facility 1. Specifically, tweezers are used to insert the seaweed seedling threads between the twists of the cultivation rope 5.

[0034] Next, the seaweed cultivation facility 1, which is equipped with seaweed seedling threads, is installed in the target coastal area. Specifically, the seaweed cultivation facility 1 is loaded onto a ship and lowered into the target coastal area. Next, the anchor rope 4 is secured to the seabed using anchor 4a to prevent the seaweed cultivation facility 1 from being carried away by ocean currents. This completes the installation of the seaweed cultivation facility 1.

[0035] After the installation of seaweed cultivation facility 1 is complete, cultivation will be carried out until the seaweed has grown. When the seaweed has grown to a state suitable for harvesting, seaweed cultivation facility 1 will be lifted from the sea and the seaweed attached to each cultivation rope 5 will be harvested. After the seaweed harvesting is complete, seaweed cultivation facility 1 can be used again by planting new seaweed seedling threads. The above outlines the process for cultivating seaweed.

[0036] As described above, the seaweed cultivation rope 1A according to the embodiment comprises a cultivation rope 5 to which seaweed is attached, a wire 6 attached to the cultivation rope 5, and a magnesium rod 7 supported by the cultivation rope 5, made of a metal material with a higher ionization tendency than the wire 6, electrically connected to the wire 6, and supplying electrons to the wire 6 when placed in the sea. As a result, minerals from the sea are attracted to the wire 6, and the growth of the entire seaweed being cultivated can be sustainably promoted.

[0037] The present invention is not limited to the embodiments described above, and the following modifications are also possible.

[0038] (modified version) In the above embodiment, magnesium or a magnesium alloy was used as the corrosion-resistant anode and iron was used as the cathode, but the present invention is not limited thereto. As the corrosion-resistant anode, any metal material with a higher ionization tendency than the metal material of the wire 6 may be used. For example, if the wire 6 is made of iron, zinc or an alloy thereof, or aluminum or an alloy thereof may be used. As the cathode, any metal material other than iron may be used, as long as it has a lower ionization tendency than the corrosion-resistant anode.

[0039] In the above embodiment, the wire 6 was wrapped around the cultivation rope 5, but the method of incorporating the wire 6 into the cultivation rope 5 in the present invention is not limited to this. For example, the wire 6 may be incorporated so as to extend in the longitudinal direction of the cultivation rope 5. Alternatively, a cultivation rope 5 with one or more wires 6 already incorporated may be used. Such a cultivation rope 5 can be manufactured, for example, by incorporating the wire 6 when twisting together multiple strands, and by using such a cultivation rope 5, the work of wrapping the wire 6 during the manufacture of the seaweed cultivation facility 1 becomes unnecessary.

[0040] In the above embodiment, a wire 6 was used as the cathode, but the present invention is not limited thereto. For example, the cathode may be a ring member that can be attached to the training rope 5, and the magnesium rod 7 and the ring member may be electrically connected with an electric wire.

[0041] In the above embodiment, a cross rope 5a was used to connect the training rope 5 to the main rope 3 and the magnesium rod 7, but the present invention is not limited thereto. Other ropes besides the cross rope 5a may be used to connect the training rope 5 to the main rope 3 and the magnesium rod 7, or each end of the training rope 5 may be directly tied to the main rope 3 and the magnesium rod 7. Furthermore, the cross rope 5a may be omitted to connect the training rope 5 to the magnesium rod 7.

[0042] In the above embodiment, the magnesium rod 7 had a circular cross-section, but the present invention is not limited thereto. The magnesium rod 7 may have a rectangular cross-section, or it may be a sphere made of magnesium or a magnesium alloy.

[0043] In the above embodiment, the magnesium rod 7 was attached to the end of the training rope 5, but the present invention is not limited to this. The magnesium rod 7 can be installed at any position on the training rope 5 as long as it can be immersed in the sea, and for example, the magnesium rod 7 may be attached to the middle portion of the training rope 5.

[0044] In the above embodiment, the training rope 5 was suspended from a single main rope 3, but the present invention is not limited to this. For example, two main ropes 3 may be arranged parallel to each other, and multiple ropes may be stretched between them to form a ladder-like structure, from which the training rope 5 may be suspended from the two main ropes 3 or from these ropes. It is preferable that the ropes stretched between the main ropes 3 have a smaller diameter than the main ropes 3.

[0045] In the above embodiment, the main rope 3 was floated by floats 2 and positioned by anchor ropes 4, but the present invention is not limited thereto. The anchor ropes 4 may be omitted, and both ends of the main rope 3 may be fixed to the seabed, while the middle section of the main rope 3 is raised to the surface of the sea by multiple floats 2. Alternatively, the main rope 3 may be fixed to a raft that is positioned by anchor ropes 4 and floated on the surface of the sea using other mooring means.

[0046] In the above embodiment, seedling threads to which seaweed zoospores were attached were planted on the cultivation rope 5, but the present invention is not limited to this. For example, a cultivation rope 5 that has grown until the young sporophytes or mature sporophytes have taken root may be used.

[0047] The embodiments described above are illustrative, and the present invention is not limited thereto. Various embodiments are possible without departing from the spirit of the invention as described in the claims. The components described in the embodiments and modifications can be freely combined. Furthermore, inventions equivalent to the invention described in the claims are also included in the present invention.

[0048] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples.

[0049] (Examples) In this example, a prototype was created in accordance with the description of the embodiment above, and it was verified whether it could promote the growth of kelp in the sea. First, larval sporophytes of kelp were attached to the cultivation rope, and then a 9 mm diameter iron wire was wrapped around it and secured with a cable tie. A 12 mm diameter, 4 m long Dia Super PP rope was used as the cultivation rope.

[0050] Next, as shown in Figure 4, the training ropes and magnesium rods were connected using 7mm diameter cross ropes. The magnesium rods are Mag Rods manufactured by Nippon Corrosion Protection Industry Co., Ltd. The dimensions of the Mag Rods are 33mm in diameter, 510mm in length, and they weigh 850g. At the time Figure 4 was taken, protective covers were attached to the Mag Rods. Next, each training rope was attached to the main rope at 2m intervals using 7mm diameter cross ropes.

[0051] In December 2023, a test unit was installed in the sea off the coast of Hokkaido, and demonstration testing commenced. After a certain period, the Normalized Difference Vegetation Index (NDVI) was calculated using satellite data. The NDVI is an index that indicates the distribution and activity of vegetation, and is expressed by the following formula. NDVI = (NIR - Red) / (NIR + Red)

[0052] NIR stands for near-infrared light reflectance, and Red stands for red light reflectance. NDVI is a normalized value between -1 and 1, with higher NDVI values ​​indicating denser vegetation. After removing the test equipment from the sea, kelp was collected from the cultivation rope, and its length, width, and weight were measured. As a comparative example, a test using a 1.0 kg lead weight instead of a mag rod was also conducted, and the two methods were compared.

[0053] The verification results, as shown in Figure 5, showed that the collected kelp grew significantly larger when a magnesium rod was used. Specifically, when a magnesium rod was used, the kelp grew to a length of 3.0m to 3.5m and a width of 10cm to 12cm, with an NDVI of 0.84. On the other hand, when a lead weight was used, the kelp grew to a length of 1.1m to 1.5m and a width of 8cm to 10cm, with an NDVI of 0.76. From these results, it was confirmed that generating a protective current in the sea using a magnesium rod promotes the growth of kelp and also increases the density of the vegetation. [Explanation of symbols]

[0054] 1. Seaweed farming facility 1A Rope for seaweed cultivation 2 floats 3 Main rope 4 Anchor ropes 5. Training rope 6 Wire 7 Magnesium Rod

Claims

1. A cultivation rope with seaweed attached, The cathode attached to the aforementioned training rope, A sacrificial anode is supported by the aforementioned training rope, is made of a metallic material with a higher ionization tendency than the cathode, is electrically connected to the cathode, and, when installed in the sea, supplies electrons to the cathode. A rope for seaweed cultivation equipped with the following features.

2. The cathode is formed from a wire incorporated into the training rope. The rope for seaweed cultivation according to claim 1.

3. The aforementioned wire is spirally wound between the twists of the training rope. The rope for seaweed cultivation according to claim 2.

4. The sacrificial anode is suspended from one end of the training rope and electrically connected to the wire. The rope for seaweed cultivation according to claim 2.

5. Seedling threads to which the zoospores of the seaweed are attached are planted on the aforementioned cultivation rope. The rope for seaweed cultivation according to claim 1.

6. The cathode is made of iron, The sacrificial anode is formed of a metallic material selected from the group consisting of magnesium, zinc, aluminum, and alloys thereof. The rope for seaweed cultivation according to claim 1.

7. A rope for seaweed cultivation according to any one of claims 1 to 6, A mooring means installed in a coastal area to secure the training rope so that it is suspended in the sea, A seaweed farming facility equipped with [equipment name].

8. A step of attaching seaweed to the cultivation rope of the seaweed cultivation rope according to any one of claims 1 to 6, The process involves setting the seaweed cultivation rope, on which the seaweed is attached, into the sea so that the sacrificial anode is facing downwards, The process of pulling up the seaweed cultivation rope installed in the sea, A method of cultivating seaweed, including the following.

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