Floating complex fishery facility and construction method thereof

Abstract

To provide a culture facility capable of circulating and utilizing nutrient salt in a labor-saving manner by utilizing natural force, and to provide a method for constructing the facility.SOLUTION: The floating body type composite fishing ground facility 10 has a flat plate-like float 20 and a culture area 40 provided on the float 20 and surrounded by a water-permeable wall 30, wherein the outer wall 31 of the water-permeable wall 30 has a gentle slope. The gentle slope constitutes a seaweed bed A.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a floating complex fishing facility and a construction method thereof. [Background technology]

[0002] Integrated multi-trophic aquaculture (IMTA) is attracting attention as an aquaculture system of the future. Integrated multi-trophic aquaculture is an aquaculture technique that combines organisms from different trophic levels in the food chain to effectively utilize fish feed and nutrients discharged from aquaculture, creating a balanced system. A common method for cultivating seafood in marine areas is to use underwater cages enclosed by nets. It has been proposed that insoluble organic matter generated in aquaculture ponds be broken down into smaller molecules, such as phosphorus and nitrogen, using a decomposition filter, and then used for cultivating seaweed and shellfish. However, excessive dissolution of nutrients such as ammonia, phosphorus, and nitrogen into seawater can lead to the growth of harmful plankton in the surrounding seawater, deteriorating water quality. In order to solve the above problems, for example, Patent Document 1 discloses an integrated fish and shellfish farming device that includes a first fish and shellfish farming cage, a second fish and shellfish farming cage, and an insoluble suspended matter removal device that passes seawater containing insoluble suspended matter such as leftover feed and feces remaining in the first fish and shellfish farming cage through a suspended matter filter to remove the insoluble suspended matter, and returns the seawater after the insoluble suspended matter has been removed to the second fish and shellfish farming cage, and is configured so that the seawater after the insoluble suspended matter has been removed is returned to the first fish and shellfish farming cage via the second fish and shellfish farming cage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-240296 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 is effective in that nutrients are utilized in the second net cage, preventing excessive scattering of nutrients in the surrounding sea area. However, the size of the second net cage is limited by the size of the first net cage, which limits the circulatory utilization of nutrients. This creates the problem that the scale of the lower region of the trophic cascade cannot be sufficiently secured. Furthermore, the biological resources that can be cultivated are limited, making this technology insufficient in terms of maintaining biodiversity. On the other hand, in the future, environmentally friendly and sustainable aquaculture facilities will also be required to be operated in a labor-saving manner in harmony with nature. The present invention has been made in consideration of the above circumstances, and aims to provide an aquaculture facility and a method for constructing the same that utilizes the power of nature and enables the labor-saving recycling of nutrients. [Means for solving the problem]

[0005] The inventors discovered that the above problem could be solved by making the aquaculture ponds floating and creating seaweed beds around the ponds that could utilize nutrients such as nitrogen, phosphorus, and low-molecular-weight compounds as a buffer zone between the ponds and natural water areas, and this led to the present disclosure. That is, the present disclosure is as follows. [1] A floating complex fishing facility having a flat float and an aquaculture area surrounded by a permeable wall provided on the float, the outer wall of which has a gently sloping surface. [2] The gently sloping surface is a floating complex fishing facility as described in [1] above, which constitutes a seaweed bed. [3] A floating complex fishing facility according to [1], wherein the aquaculture area comprises at least one first aquaculture pond, at least one second aquaculture pond horizontally adjacent to the first aquaculture pond, and a biological treatment device disposed within the second aquaculture pond for filtering and decomposing aquaculture waste generated in the first aquaculture pond. [4] A floating complex fishing facility as described in [1], which is equipped with a water quality monitoring device on the outer wall of the permeable wall that measures the concentration of nutrients in the water, and controls the active circulation of water according to the concentration of nutrients. [5] A method for constructing a floating complex fishing facility having a flat float and an aquaculture area surrounded by a permeable wall provided on the float, in which the permeable wall is constructed on the flat float so that the outer wall has a gently sloping surface. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide an aquaculture facility and a method for constructing the same that utilizes the power of nature and allows for the labor-saving recycling of nutrients. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic plan view of the floating integrated fishing ground facility of this embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view of a permeable wall. [Figure 3] 2 is a cross-sectional view taken along the line Y1-Y1 in FIG. 1. [Figure 4] 2 is a cross-sectional view taken along the line Y2-Y2 in FIG. 1. [Figure 5] FIG. 2 is a schematic cross-sectional view showing the configuration of a biological treatment device. [Figure 6] This is a schematic plan view of another floating complex fishing area connected together. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0009] [Floating complex fishing facility] As shown in Figure 1, the floating complex fishing ground facility 10 of this embodiment has a flat float 20 and an aquaculture area 40 surrounded by a permeable wall 30 provided on the float 20, and the outer wall 31 of the permeable wall 30 has a gently sloping surface. In this specification, the term "gentle inclined surface" refers to a surface having an inclination such that when the vertical length is 1, the horizontal length is 1.5 or more. Each component will be described in detail below.

[0010] <float> The float 20 may be a conventional float used in floating facilities, such as one made of steel or concrete.

[0011] The planar shape of the float 20 is not particularly limited, and examples include a circle, an ellipse, and a polygon, but from the viewpoint of efficiently providing an aquaculture area, a rectangular shape as shown in Fig. 1 is particularly preferable. A rectangular shape makes it possible to connect multiple floating complex fishing ground facilities 10 to form a large-scale aquaculture ground.

[0012] The size of the float 20 is set to approximately 7.5 x 10 in terms of the plane area from the viewpoint of structurally establishing the floating complex fishing ground facility 10. 3 m 2 Over 3.0 x 10 4 m 2 For example, in the case of a rectangle, as shown in Fig. 1, the length W of the long side is preferably 150 m or more and 300 m or less, and the length L of the short side is more preferably 50 m or more and 100 m or less.

[0013] As shown in Figure 3, the buoyancy and weight of the float 20 are preferably adjusted so that the upper surface of the permeable wall 30 floats and the depth D from the sea surface S to the upper surface 20a of the float 20 is within 20 m. It is more preferable to adjust the depth D to within 15 m. This is because the depth is such that sunlight can reach the outer wall 31 of the permeable wall 30 where the seaweed bed A will be formed.

[0014] The float 20 is moored to the seabed, for example, by a TLP method using a mooring rope 90.

[0015] <Permeable wall> The outer wall 31 of the permeable wall 30 constituting the aquaculture area 40 of this embodiment has a gently sloping surface. The gently sloping surface may be a gently sloping surface over the entire surface of the outer wall 31, or may be a stepped gently sloping surface with a horizontal plane midway through the gently sloping surface. The outer wall 31 may also have a V-shaped notch 33 to increase the area of ​​the slope, as shown in FIG. 1 . This V-shaped notch 33 may or may not be a gently sloping surface. The shape of the notch is not limited to a V shape and may be a U-shape, or may be a combination of slopes with different inclination angles, stepped slopes, and other shapes.

[0016] The detailed construction method of the permeable wall 30 will be described later, but as shown in Figure 2, it is constructed by stacking blocks 38, which are made of porous concrete artificial rock filled in gabions, on top of the float 20 so that the outer wall 31 forms a gently sloping surface. The void ratio of the porous concrete is preferably 20% or more and 30% or less, and the gabion volume ratio is preferably 60% or more and 80% or less, and more preferably 70% or more and 80% or less. By using such materials and configuring the permeable wall 30, there are appropriate gaps between the blocks 38 made of porous concrete, allowing water to pass from the aquaculture area 40 to the surrounding sea area.

[0017] It is preferable to provide an upper float 32 on the upper part of the permeable wall 30 to prevent the floating complex fishing ground facility 10 from capsizing.

[0018] As shown in Figure 1, it is preferable to provide a management passage 34a on the raised upper surface of the permeable wall 30 so that people, monitoring vehicles, monitoring robots, etc. can pass through. It is also preferable to provide a management passage 34b between the first aquaculture pond 50 and the second aquaculture pond 60.

[0019] It is preferable to provide a pier 35 extending from the permeable wall 30 so that fishing boats and other vessels, such as management vessels, can dock. Furthermore, an aquaculture experience facility 36 may be constructed adjacent to the pier 35, and used as a place for cultivation experiments, aquaculture experiences, education, seminars, and the like.

[0020] 2, the thickness T2 of the permeable wall 30 near the sea surface is preferably 2 m or more and 4 m or less in order to enable the formation of the management passages 34a and 34b. The thickness T1 of the base of the permeable wall 30 is determined by the depth and the gentle slope.

[0021] <Aquaculture area> As shown in Figure 1, the aquaculture area 40 comprises at least one first aquaculture pond 50, at least one second aquaculture pond 60 horizontally adjacent to the first aquaculture pond 50, and a biological treatment device 70 disposed within the second aquaculture pond 60 to filter and decompose aquaculture waste generated in the first aquaculture pond 50. In this specification, the term "aquaculture residue" refers to materials that are generated in the first aquaculture pond 50 and include insoluble organic matter such as leftover feed and feces. The bottom surface of the aquaculture area 40 is formed by the upper surface 20a of the float 20, and the side wall is surrounded by the permeable wall 30.

[0022] As shown in Figure 3, seawater flows into the first aquaculture pond 50 and the second aquaculture pond 60 through a pipe 42 installed along the outer wall 31 of the permeable wall 30 by a water pump 41 installed outside the permeable wall 30. Once the first aquaculture pond 50 and the second aquaculture pond 60 are filled with seawater and aquaculture has begun, seawater is actively introduced into at least the first aquaculture pond 50, and further, by operating the pumps described below, a positive flow of water is generated toward the biological treatment device 70 and the second aquaculture pond 60, enabling water to pass from the aquaculture area 40 to the surrounding sea area.

[0023] (1st aquaculture pond) As shown in Figure 3, a plurality of aquaculture cages 51 are installed in the first aquaculture pond 50, and fish 52 such as tuna, sea bream, horse mackerel, and mackerel are cultivated in them. A plurality of different types of aquaculture cages 51 can be installed, and different fish species can be cultivated in each aquaculture cage 51.

[0024] It is preferable to provide a waterproof sheet 56 between the first aquaculture pond 50 and the second aquaculture pond 60, from the sea level S to the bottom surface 57. By providing the waterproof sheet 56, it is possible to prevent aquaculture waste from spreading to the adjacent second aquaculture pond 60. The waterproof sheet 56 only needs to be provided in the area where the first aquaculture pond 50 and the second aquaculture pond 60 are adjacent to each other, but it may also be provided so as to surround the first aquaculture pond 50 on all four sides.

[0025] Feeding of the first aquaculture pond 50 can be carried out through the management passage 34b. Aquaculture waste generated in the first aquaculture pond 50 floats near the bottom of the first aquaculture pond 50. This aquaculture waste is discharged by a pump 53 installed at the bottom of the first aquaculture pond 50 through pipes 54 and 55 to a biological treatment device 70 (see Figure 4).

[0026] Seawater is constantly flowing into the first aquaculture pond 50 by a water pump 41 installed outside the permeable wall 30. As a result, nutrients contained in the seawater in the first aquaculture pond 50, including urine-derived ammonia, nitrogen, phosphorus, etc., pass through the permeable wall 30 and seep out around the outer wall 31. The outer wall 31 in contact with the first aquaculture pond 50 has a gentle slope, allowing sunlight to be captured, and seaweed and the like can be transplanted to form a seaweed bed A. The seeped nutrients are then effectively utilized by the seaweed bed A.

[0027] When cultivating fish that do not like sunlight in the first aquaculture pond 50, solar panels can be installed in the upper area to block sunlight. Also, by installing solar panels, it is possible to secure electricity for the floating complex fishing ground facility 10.

[0028] (Biological treatment equipment) As shown in FIG. 4, the biological treatment device 70 is installed in the second aquaculture pond 60. For example, as shown in FIG. 5, the biological treatment device 70 is composed of tanks a, b, and c. Seawater containing aquaculture residues, pumped from the first aquaculture pond 50, flows into tank a through pipe 71. The seawater containing the aquaculture residues is then sent sequentially to tanks b and c by an aeration device 73 and filtered. Tank c contains a biological carrier 74 to which microorganisms that decompose organic matter are attached. The biological carrier 74 decomposes the aquaculture residues into low-molecular-weight compounds containing nitrogen and phosphorus. The resulting seawater, together with urine-derived ammonia and other nutrients, is discharged through pipe 72 into the second aquaculture pond 60. The organic matter decomposition function can be further enhanced by allowing organisms, such as amphipods and lugworms, to settle in tank c, which break down solid residues.

[0029] (Second aquaculture pond) As shown in Figure 4, the second aquaculture pond 60 is an aquaculture pond that uses seawater containing nutrients that has been filtered and decomposed by a biological treatment device 70. Because the seawater that has been filtered and decomposed by the biological treatment device 70 is rich in nutrients, it is suitable for cultivating seaweed, bivalve shells, and the like using sunlight. These types of cultivation can be carried out, for example, by installing a seaweed cultivation raft 61 for cultivating seaweed and a bivalve shell cultivation raft 62 for cultivating bivalve shells.

[0030] Nutrients not used in the second aquaculture pond 60 are supplied from the second aquaculture pond 60 to the outer wall 31 through the permeable wall 30. The outer wall 31 in contact with the second aquaculture pond 60 is also a gently sloping surface, allowing sunlight to be captured, and seaweed and the like can be transplanted to form a seaweed bed A. The seeped-out nutrients are then effectively utilized by the seaweed bed A.

[0031] As in the first aquaculture pond 50, a pump 63 for sucking up insoluble organic matter may be installed at the bottom 67 of the second aquaculture pond 60, and the insoluble organic matter may be returned to the biological treatment device 70 (see FIG. 4) through pipes 64 and 65. This configuration prevents the seawater in the second aquaculture pond 60 from becoming cloudy, and also prevents the accumulation of insoluble organic matter from forming oxygen-deficient areas and generating harmful substances such as sulfide ions.

[0032] (weed bed) Because the outer wall 31 of the permeable wall 30 is a gently sloping surface, the depth D is approximately 18 m or less, allowing sunlight to penetrate. Therefore, by transplanting seaweed and the like onto the gently sloping surface, a seaweed bed A is formed. In particular, the floating integrated fishing ground facility 10 can establish a seaweed bed A on the gently sloping surface around the entire perimeter of the aquaculture area 40, making it possible to provide a large-scale seaweed bed A. Furthermore, because the aquaculture area 40 uses a water pump 41 to generate a positive water flow, excess nutrients not used in the first aquaculture pond 50 and the second aquaculture pond 60 seep through the permeable wall 30 into the gently sloping seaweed bed A. The seeped nutrients are absorbed by the seaweed in the seaweed bed A and photosynthesize, making it possible to provide an even larger seaweed bed A. As the seaweed bed A grows larger, it will become a habitat for a variety of organisms, including fish, sea urchins, abalone, sea cucumbers, and root fish, and will also be able to provide a spawning site and a nursery for young fish and fry.

[0033] (Water quality monitoring device) As shown in Figure 1, the floating integrated fishing ground facility 10 preferably includes a water quality monitoring device 80 for measuring the concentration of nutrients in the water on the outer wall 31 of the permeable wall 30, particularly on the periphery of the gently sloping surface. By installing the water quality monitoring device 80, the concentration of nutrients seeping out from the permeable wall 30 can be measured. The water quality monitoring device 80 may be equipped with a measuring unit that measures predetermined ion concentrations, such as ammonium ions, nitrate ions, phosphate ions, and dissolved organic matter (TOC), which are indicators of eutrophication, at the edge of the seaweed bed, and a transmitting unit that transmits the results to a management unit on land.

[0034] The active circulation of water is controlled according to the measured nutrient concentration. That is, if it is estimated that the nutrient concentration will leak out of the seaweed bed, the inflow of seawater by the water pump 41 installed outside the permeable wall 30 is stopped, and if the situation improves, operation is resumed. In this way, by monitoring the water quality around the aquaculture area 40, it is possible to control the seepage of nutrients, thereby preventing the surrounding sea area from becoming eutrophic due to nutrients and providing a seaweed bed fishing reef rich in biological resources.

[0035] In the floating integrated fishing ground facility 10 of this embodiment, the second aquaculture pond 60 serves as the first buffer zone between the aquaculture pond and the surrounding sea area, and the seaweed bed A with a gently sloping surface serves as the second buffer zone. With this configuration, the surrounding sea area will not be polluted with aquaculture waste, and nutrients can be effectively recycled and reused. Furthermore, Seaweed Bed A will contribute to the maintenance of biodiversity by providing a fishing ground for sea urchins, abalone, sea cucumbers, and bottom fish, as well as a diverse fishing ground for raising eggs, fry, and young fish, and for the production of seedlings and other aquaculture activities. Furthermore, by establishing a large-scale seaweed bed A, photosynthesis of seaweed will become more active, and oxygen essential for the survival of living organisms can also be supplied.

[0036] In the above embodiment, the case where there is one floating complex fishing ground facility 10 has been described, but as shown in Fig. 6, it is also possible to have a configuration in which multiple floating complex fishing ground facilities 10 are connected by a connecting device 91. By using such a configuration, it is possible to obtain a more diverse range of fishery resources while ensuring a large scale in the lower region of the trophic cascade.

[0037] Bays and inland seas with gentle ocean currents are ideal for the floating complex fishing facility 10. For example, Osaka Bay was once home to a wide variety of fish and shellfish, and as fishing grounds are developed, it is believed that the area will be reborn as a rich fishing region.

[0038] The floating complex fishing ground facility 10 can produce fry and seedlings stably throughout the year, allowing for backup farming of valuable fish species. It can also provide a place for children and students to experience and research.

[0039] In the above embodiment, the floating integrated fishing ground facility 10 is described as being used in sea areas, but it can also be used in lakes and lagoons.

[0040] [Construction method of a floating complex fishing facility] The construction method for a floating complex fishing ground facility of this embodiment is a construction method for a floating complex fishing ground facility 10 having a flat float 20 and an aquaculture area 40 surrounded by a permeable wall 30 provided on the float 20, in which the permeable wall 30 is constructed on the flat float 20 so that the outer wall 31 of the permeable wall 30 has a gently sloping surface.

[0041] Specifically, the floating complex fishing ground facility 10 is constructed by first constructing a float 20 on land or near a quay. Next, as shown in Figure 2, an L-shaped reinforced concrete retaining wall 37 is installed at the planned construction location of the permeable wall 30 on the upper surface 20a of the float 20, and then porous concrete artificial rock blocks 38 are piled up. Furthermore, porous concrete connected artificial rocks 39 are piled up on the surface to construct the permeable wall 30. As described above, it is preferable to construct the upper float 32, management walkways 34a and 34b, and pier 35 on the permeable wall 30. Next, pumps 53 and 63, pipes 54, 55, 64, and 65, etc. are installed in the aquaculture area 40, and then the first aquaculture pond 50, the second aquaculture pond 60, the waterproof sheet 56, the aquaculture cages 51, the seaweed aquaculture rafts 61, the bivalve aquaculture rafts 62, the biological treatment device 70, the power supply unit (not shown), etc. are installed. Finally, the aquaculture facility equipped with the above-mentioned equipment is towed to a designated location in the bay and moored to the TLP with mooring ropes 90.

[0042] Thereafter, seawater is introduced into the first aquaculture pond 50 and the second aquaculture pond 60 using the water pump 41, and the fry and young fish to be cultured are released into the pond, and aquaculture begins. [Explanation of symbols]

[0043] 10. Floating Complex Fishing Ground Facility 20 Float 20a Top of float 30 Permeable wall 31 Exterior Wall 32 Upper float 33 V-shaped notch 34a, 34b Management aisle 35 Pier 36 Aquaculture Experience Facility 37 RC L-shaped retaining wall 38 blocks 39 Porous concrete interlocking imitation rock 80 Water Quality Monitoring Device 40 Aquaculture area 41 Water pump 42 Piping 50 First aquaculture pond 51 Aquaculture Cage 52 Fish 53 Pump 54, 55 Piping 56 Waterproof sheet 60 Second aquaculture pond 61 Seaweed farming raft 62 Bivalve Aquaculture Raft 63 Pump 64, 65 Piping A Seaweed Bed 70 Biological treatment equipment 71, 72 Piping 73 Aeration equipment 74 Biocarriers 90 Mooring rope 91 Coupling device

Claims

1. The aquaculture system has a flat float and an aquaculture area provided on the float and surrounded by a water-permeable wall, A floating complex fishing ground facility in which the outer wall of the permeable wall has a gently sloping surface.

2. 2. A floating complex fishing ground facility according to claim 1, wherein the gently sloping surface forms a seaweed bed.

3. 2. The floating complex fishing facility of claim 1, wherein the aquaculture area comprises at least one first aquaculture pond, at least one second aquaculture pond horizontally adjacent to the first aquaculture pond, and a biological treatment device disposed within the second aquaculture pond for filtering and decomposing aquaculture waste generated in the first aquaculture pond.

4. a water quality monitoring device for measuring the concentration of nutrients in water is provided on the outer wall of the permeable wall; 2. The floating complex fishing ground facility according to claim 1, wherein the active circulation of water is controlled according to the concentration of said nutrients.

5. A method for constructing a floating complex fishing ground facility having a flat float and an aquaculture area provided on the float and surrounded by a water-permeable wall, A method for constructing a floating complex fishing ground facility, in which the permeable wall is constructed on the flat float so that the outer wall of the permeable wall has a gently sloping surface.

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