Seaweed cultivation rope, seaweed cultivation facility and seaweed cultivation method

Abstract

Provided are a seaweed cultivation rope, a seaweed cultivation facility, and a seaweed cultivation method that can continuously promote the growth of all seaweed to be cultivated. [Solution] The seaweed cultivation rope 1A comprises a training rope 5 with seaweed attached, a wire 6 attached to the training rope 5, and a magnesium rod 7 supported by the training 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 technology]

[0002] In recent years, seaweed cultivation production has been declining due to environmental changes such as rising seawater temperatures, which has led to a decline in fishermen's production. Therefore, efforts are being made to develop cultivation methods that effectively promote seaweed growth. For example, Patent Document 1 discloses a cultivation method that uses a rope impregnated with fertilizer for seaweed cultivation, the hollow part of which is filled with fertilizer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-263815 Summary of the Invention [Problem to be solved by the invention]

[0004] The cultivation method of Patent Document 1 involves floating ropes containing seaweed fertilizer on the ocean surface, which makes it difficult for the fertilizer leached from the surface to spread throughout the seaweed in the ocean, resulting in slower growth of some of the seaweed. Furthermore, there is a limit to the amount of fertilizer that can be stored in the rope, meaning that if all the fertilizer leaches out of the rope, it will need to be replaced. Conversely, if the concentration of fertilizer is too high, it could cause red tides.

[0005] The present invention has been made based on this background, and aims to provide a seaweed cultivation rope, a seaweed cultivation facility, and a seaweed cultivation method that can sustainably promote the growth of the entire seaweed being cultivated. [Means for solving the problem]

[0006] In order to achieve the above object, the rope for seaweed cultivation according to the present invention is A training rope with seaweed attached, A cathode attached to the training rope; a sacrificial anode supported by the training rope, formed of a metal material having a higher ionization tendency than the cathode, electrically connected to the cathode, and configured to supply electrons to the wire when placed in the sea; Equipped with. [Effects of the Invention]

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

[0008] [Figure 1] 1 is a front view showing the configuration of a seaweed cultivation facility according to an embodiment of the present invention. [Figure 2] 1 is a front view showing the relationship between the training rope and the wire in a seaweed cultivation rope according to an embodiment of the present invention. FIG. [Figure 3] 1 is a diagram showing a magnesium rod covered with a protective cover in a seaweed cultivation rope according to an embodiment of the present invention. FIG. [Figure 4] FIG. 1 is a photograph of the exterior of a prototype in an example. [Figure 5] FIG. 1 is a photograph of the appearance of kelp cultivated using the prototype machine in the example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a seaweed cultivation rope, 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 designated by the same reference numerals.

[0010] In the embodiments, "seaweed attaches" is not limited to the attachment of seaweed sporophytes, but also includes the attachment of any of seaweed zoospores, gametophytes, and fertilized eggs. Sporophytes include young sporophytes and mature sporophytes. Furthermore, it is not limited to direct attachment of these to the target object, but also includes the planting of seed filaments with these attached into the target object.

[0011] The seaweed cultivation facility according to the embodiment is a device that promotes the growth of seaweed attached to a training rope by attracting minerals from seawater to the training rope while the training rope is installed in the sea. The seaweed may be of any type, but examples include kelp, wakame, mozuku, and nori, with kelp, especially japonica, being preferred. The training rope may be implanted with seed threads bearing seaweed zoospores. The seed threads may be, for example, Cremona twisted threads with a diameter of 2 mm, which have been previously soaked in a liquid containing seaweed zoospores to attach the seaweed zoospores.

[0012] In the seaweed cultivation facility according to the embodiment, an iron wire is wound around a cultivation rope, a magnesium rod is connected to the end of the cultivation rope, and the wire and the magnesium rod are electrically connected. As a result of intensive 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, the growth of seaweed is promoted and a harvest yield of about two to three times that of conventional cultivation methods can be achieved.

[0013] To explain how it works, magnesium and its alloys are metals with a higher ionization tendency than iron wire. Therefore, when a magnesium rod and a wire are electrically connected and immersed in seawater, which acts as an electrolyte, a battery is formed with the magnesium rod as the anode and the iron wire as the cathode. Magnesium ions (Mg 2+ This generates a potential difference between the magnesium rod and the wire, which supplies electrons to the wire and causes a protective 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 cations such as calcium ions, magnesium ions, and iron ions, are attracted to the wire to bond with the electrons, and these minerals are continuously supplied to the kelp attached to the rope. At this time, because electrons are continuously supplied to the wire from the magnesium rod, it does not rust due to a reduction action and functions as a cathode as long as the magnesium rod is present.

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

[0016] The seaweed cultivation rope 5, wire 6, and magnesium rod 7 of the seaweed cultivation facility 1 constitute a seaweed cultivation rope 1A. The float 2, main rope 3, and anchor rope 4 are an example of mooring means that are installed in coastal waters and that moor the seaweed cultivation rope 1A so that it can be suspended in the sea. Each component of the seaweed cultivation facility 1 will be explained below.

[0017] The float 2 is, for example, a buoy used as a marker. The float 2 has an insertion hole through which the main rope 3 can be inserted, and the main rope 3 is tied to the insertion hole. The size and number of floats 2 used in the seaweed cultivation facility 1 may be determined taking into consideration the weight of the seaweed cultivation facility 1 and the seaweed, and the strength of the ocean current. As time passes after the installation of the seaweed cultivation facility 1, the seaweed grows and various organisms other than seaweed attach to it, so additional floats 2 may be added during cultivation depending on how deeply the seaweed cultivation facility 1 sinks.

[0018] The main rope 3 has a strength sufficient to prevent it from being cut by external forces from ocean currents or drifting debris, and is, for example, a three-strand rope made of polypropylene. Support ropes 5 are tied to the main rope 3 at intervals along the length of the main rope 3. The interval between adjacent support ropes 5 is, for example, within the range of 1 m to 5 m, and is preferably 2 m.

[0019] The anchor rope 4 positions the float 2 and main rope 3 so that they are not carried away by ocean currents. The anchor rope 4 is fixed to the seabed by anchors 4a driven into the seabed. The anchor rope 4 may also be fixed to the seabed by means other than the anchors 4a, for example, by sandbags or blocks.

[0020] The training rope 5 is a rope in which seaweed seed threads are planted and formed so that the sprouted seaweed can take root against ocean currents. The training rope 5 is twisted, and the seaweed seed threads are planted between the twists.

[0021] The training rope 5 has a strength sufficient to prevent it from being cut by external forces caused by ocean currents or drifting debris. The training rope 5 may be a rope of the same or equivalent construction as the main rope 3, for example, a three-strand rope made of polypropylene. The diameter of the training rope 5 may be set taking into consideration the required strength, and may be the same as or thinner than the main rope 3. Specifically, the diameter of the training rope 5 is, for example, in the range of 5 mm to 20 mm, preferably in the range of 10 mm to 15 mm, and more preferably 12 mm. The length of the training rope 5 may be set taking into consideration the depth of the seabed and the strength of the ocean current, and is, for example, in the range of 1 m to 10 m, preferably in the range of 2 m to 6 m, and more preferably 4 m.

[0022] The training rope 5 is connected to the main rope 3 and the magnesium rod 7 using a cross rope 5a. The cross rope 5a is an example of a connecting rope that connects the training rope 5 to the main rope 3 and the magnesium rod 7. The cross rope 5a is also called an eight rope, and is a rope made by twisting together a total of four pairs of strands, each pair consisting of two strands, and has the property of being flexible and resistant to kinking. The diameter of the cross rope 5a is set taking into consideration strength and ease of tying, and is, for example, in the range of 5 mm to 10 mm, and preferably 7 mm.

[0023] The wire 6 can be wound around the training rope 5 and is made of steel such as carbon steel or alloy steel. As shown in Figure 2, the wire 6 is wound between the strands of the training rope 5, and in this state the training rope 5 and the wire 6 are fastened together using a cable tie 6a. Because the wire 6 is wound spirally around the training rope 5, when the wire 6 acts as a cathode in the sea, it can attract cations in seawater to the entire training rope 5.

[0024] Returning to FIG. 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 metallic 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 may be set taking into consideration the continuity and current density of the anticorrosive current in the sea, and the role of the magnesium rod 7 as a weight. The diameter of the magnesium rod 7 is, for example, within a range of 10 mm to 50 mm, and its length is, for example, within a 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, with a ring member 7a welded to one end, through which the cross rope 5a and wire 6 can be inserted. The cross rope 5a is inserted into the ring member 7a, and the cross rope 5a is tied to the training rope 5, thereby mechanically connecting the training rope 5 and the magnesium rod 7. Furthermore, the wire 6 is inserted into the ring member 7a and tied to it, thereby electrically connecting the wire 6 and the magnesium rod 7. The above is the configuration of the seaweed cultivation facility 1.

[0026] Because the seaweed cultivation facility 1 has the above-mentioned 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 to the area around the training rope 5. As a result, the growth of the seaweed planted on the training rope 5 is promoted. It takes a long time for the magnesium rod 7 to completely dissolve, and because minerals in seawater are inexhaustible, minerals are supplied semi-permanently to the area around the training rope 5. In addition, because the magnesium rod 7 is connected to the end of the training rope 5 and the training rope 5 is connected to the main rope 3 so that the magnesium rod 7 is on the lower side, the magnesium rod 7 also functions as a weight, making it less likely for adjacent training ropes 5 to become tangled.

[0027] Next, the flow of the manufacturing method of the seaweed cultivation facility 1 according to the embodiment will be described. First, wire 6 is wound around each training rope 5 and secured so that it does not come off. Specifically, wire 6 is wound spirally between the twists of the training rope 5, and the training rope 5 and wire 6 are fastened together with a cable tie 6a to secure them so that they do not come off.

[0028] Next, the cross ropes 5a are used to mechanically connect each training rope 5 to the magnesium rod 7, and also to electrically connect the wires 6 to the magnesium rods 7. Specifically, the cross ropes 5a are passed through the ring members 7a of the magnesium rods 7, and the cross ropes 5a are tied to one end of the training ropes 5. Furthermore, the wires 6 are passed through the ring members 7a and tied.

[0029] Next, multiple training ropes 5 are connected to the main rope 3 at intervals in 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, floats 2 are attached to both ends of the main rope 3, and anchor ropes 4 are attached to each float 2. Specifically, the main rope 3 is passed through and tied to the through hole of the float 2, and the anchor rope 4 is passed through and tied to the other through hole of the float 2. The above is the flow of the manufacturing method of the seaweed cultivation facility 1.

[0031] During the manufacture 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 catching fire due to a strong impact, and is removed before the seaweed cultivation facility 1 is installed in the sea.

[0032] Next, a description will be given of the flow of the seaweed cultivation method using the seaweed cultivation facility 1 according to the embodiment. Hereinafter, it is assumed that seaweed seed threads have seaweed zoospores attached thereto.

[0033] First, on land, seaweed seed threads are attached to each training rope 5 of the seaweed cultivation facility 1. Specifically, the seaweed seed threads are inserted between the twists of the training rope 5 using tweezers.

[0034] Next, the seaweed cultivation facility 1 with the seaweed seed threads set is installed in the target coastal waters. Specifically, the seaweed cultivation facility 1 is loaded onto a ship and dropped into the target coastal waters. Next, the anchor rope 4 is fixed to the seabed using an 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 the seaweed cultivation facility 1 is completed, seaweed cultivation is continued until it grows. When the seaweed grows to a state suitable for harvesting, the seaweed cultivation facility 1 is pulled out of the sea, and the seaweed attached to each cultivation rope 5 is harvested. After the seaweed harvesting is completed, new seaweed seed threads can be planted in the seaweed cultivation facility 1 and used for cultivation again. The above is the flow of seaweed cultivation method.

[0036] As explained above, the seaweed cultivation rope 1A according to the embodiment comprises a training rope 5 to which seaweed is attached, a wire 6 attached to the training rope 5, and a magnesium rod 7 supported by the training 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 in the sea are attracted to the wire 6, which can continuously promote the growth of the entire seaweed to be cultivated.

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

[0038] (Variation) In the above embodiment, magnesium or a magnesium alloy is used as the anticorrosion anode and iron is used as the cathode, but the present invention is not limited to this. The anticorrosion anode may be made of any metal material having a higher ionization tendency than the metal material of the wire 6. For example, if the wire 6 is made of iron, zinc or its alloy, or aluminum or its alloy may be used. Metal materials other than iron may also be used for the cathode as long as they have a lower ionization tendency than the anticorrosion anode.

[0039] In the above embodiment, the wire 6 was wound around the training rope 5, but the method of incorporating the wire 6 into the training rope 5 in the present invention is not limited to this. For example, the wire 6 may be incorporated so that it extends in the longitudinal direction of the training rope 5. Also, a training rope 5 with one or more wires 6 already incorporated therein may be used. Such a training rope 5 is manufactured, for example, by incorporating the wire 6 when twisting together multiple strands, and using such a training rope 5 eliminates the need for the work of winding the wire 6 when manufacturing the seaweed cultivation facility 1.

[0040] In the above embodiment, the wire 6 is used as the cathode, but the present invention is not limited to this. 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 by 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 to this. A rope other than 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 tied directly to the main rope 3 and the magnesium rod 7. Also, the cross rope 5a may be omitted from connecting the training rope 5 to the magnesium rod 7.

[0042] In the above embodiment, the magnesium rod 7 has a circular cross section, but the present invention is not limited to this. The magnesium rod 7 may have a rectangular cross section, or may be a sphere made of magnesium or a magnesium alloy, for example.

[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 relative to the training rope 5 as long as it can be immersed in the sea. For example, the magnesium rod 7 may be attached to the middle part of the training rope 5.

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

[0045] In the above embodiment, the main rope 3 is floated by the float 2 and positioned by the anchor rope 4, but the present invention is not limited to this. The anchor rope 4 may be omitted, and both ends of the main rope 3 may be fixed to the seabed, with the middle part of the main rope 3 floating on the sea surface by multiple floats 2. The main rope 3 may also be positioned by other mooring means, for example, anchor ropes 4, and fixed to a raft floating on the sea surface.

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

[0047] The above-described embodiments are merely examples, and the present invention is not limited to these. Various embodiments are possible within the scope of the invention as set forth in the claims. The components described in the embodiments and modifications can be freely combined. Furthermore, inventions equivalent to the inventions set forth in the claims are also included in the present invention.

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

[0049] (Example) In the example, a prototype was created in accordance with the above-described embodiment, and it was verified whether it could promote the growth of Laminaria japonica in the sea. First, young sporophytes of Laminaria japonica were attached to a training rope, and then a 9 mm diameter iron wire was wrapped around it and secured with a cable tie. A Dia Super PP rope with a diameter of 12 mm and a length of 4 m was used as the training rope.

[0050] Next, as shown in Figure 4, the training ropes and magnesium rods were connected using cross ropes with a diameter of 7 mm. The magnesium rods were mag rods manufactured by Nippon Corrosion Industry Co., Ltd. The mag rods had dimensions of 33 mm in diameter, 510 mm in length, and weighed 850 g. At the time Figure 4 was photographed, a protective cover had been installed to cover the mag rods. Next, each training rope was attached to the main rope at intervals of 2 m using cross ropes with a diameter of 7 mm.

[0051] A test device was installed underwater in the coastal waters of Hokkaido in December 2023, and demonstration tests began. After a certain period of time, satellite data was used to calculate the Normalized Difference Vegetation Index (NDVI). NDVI is an index that shows the distribution and activity of vegetation, and is expressed by the following formula. NDVI=(NIR-Red) / (NIR+Red)

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

[0053] As a result of the experiment, as shown in Figure 5, the kelp collected using the magnesium rod grew much larger. Specifically, when the 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 the lead sinker 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 the above, it was confirmed that generating a protective current in the sea using a magnesium rod promotes the growth of kelp and also makes the vegetation denser. [Explanation of symbols]

[0054] 1. Seaweed farming facility 1A Seaweed farming rope 2. Float 3 Main rope 4 anchor rope 5 Training rope 6 Wire 7 Magnesium Rod

Claims

1. A training rope with seaweed attached, A cathode attached to the training rope; a sacrificial anode supported by the training rope, formed of a metal material having a higher ionization tendency than the cathode, electrically connected to the cathode, and configured to supply electrons to the cathode when placed in the sea; A rope for seaweed farming.

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

3. The wire is spirally wound between the strands 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 the wire is electrically connected to the sacrificial anode. The rope for seaweed cultivation according to claim 2.

5. The breeding rope is planted with seedling threads to which the seaweed zoospores are attached. The rope for seaweed cultivation according to claim 1.

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

7. The seaweed cultivation rope according to any one of claims 1 to 6, Mooring means installed in coastal waters for mooring the training rope so that it can be suspended in the sea; A seaweed farming facility equipped with:

8. A step of attaching the seaweed to the training rope of the seaweed cultivation rope according to any one of claims 1 to 6; A step of installing the seaweed cultivation rope with the seaweed attached to the training rope in the sea so that the sacrificial anode is on the bottom; A step of pulling up the seaweed cultivation rope installed in the sea; A seaweed farming method comprising:

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