Method and apparatus for cultivating shellfish

Abstract

To provide a method and apparatus for cultivating shellfish efficiently. [Solution] Shellfish are raised using a shellfish rearing device. In this case, a rearing container 10 is immersed in a tank of water. The container has a frame 11 with holes 11h smaller than the shellfish in its bottom 11b, to which multiple partition plates 13 are erected to create partitioned spaces. The shellfish are then attached to the partition plates 13, water is supplied to the partitioned spaces, and the shellfish are fed.

Description

Technical Field

[0001] The present disclosure relates to a method for cultivating shellfish such as abalone and a shellfish cultivation device for cultivating shellfish.

Background Art

[0002] For the purpose of ensuring sustainable fishery resources, etc., land-based cultivation of shellfish such as abalone has been studied (for example, Patent Documents 1 to 3). The shellfish cultivation system described in Patent Document 1 controls a circulation path for filtering the breeding water in the breeding tank of shellfish and returning it to the breeding tank. Then, seawater with an increased calcium ion concentration is supplied to the breeding tank so that the calcium ion concentration of the breeding water becomes not less than a reference value.

[0003] In addition, in the technique described in Patent Document 2, in order to enable completely closed-loop land-based cultivation of abalones, a plurality of breeding cages arranged while forming a water flow space between the bottom of the breeding tank main body, and a shelter accommodated in a plurality of sheets arranged vertically in each of the breeding cages are provided. Further, air generation means arranged below the breeding cages and sludge pockets formed at a plurality of locations on the bottom of the breeding tank are provided.

[0004] In addition, the abalone growth container described in Patent Document 3 includes a container main body having an opening formed at the upper part and a lid detachably provided with respect to the opening of the container main body. And when the lid is attached to the container main body, a shelter extending downward and having a lower end substantially contacting the bottom surface of the container main body is provided.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0006] To achieve high-density abalone farming, it is necessary to introduce a large number of abalone into a tank. In the free-range farming method described in Patent Document 1, the abalone are densely packed at the bottom of the tank. Therefore, it is difficult to increase the amount of shellfish farmed.

[0007] Furthermore, Patent Document 2 describes attaching abalone to both sides of shelters used as hiding places, and placing seaweed such as kelp or sheet-shaped compound feed between the shelters. Due to the abalone's instinct to protect itself from predators, it hides in the shade of the shelters during the day and crawls out at night to feed. However, due to feeding behavior, it can sometimes be difficult to maintain seaweed such as kelp or sheet-shaped compound feed between the shelters. In particular, when many individuals are raised in a group, the overcrowded conditions during the day and the feeding behavior at night lead to a so-called fast-eating competition. As a result, only the stronger individuals feed, and the weaker individuals are eliminated.

[0008] Furthermore, if the amount of food provided is calculated based on the number of individuals, a buildup of uneaten food can occur, creating a fouling accumulation. If the circulation of the rearing water is insufficient, this buildup can cause the generation of harmful substances such as hydrogen sulfide. In the configuration of Patent Document 3, excrement is separated from the abalone by through-holes, but depending on the water flow, it may not be possible to completely remove it. [Means for solving the problem]

[0009] A shellfish cultivation method that solves the above problems is a method of raising shellfish using a shellfish cultivation device, wherein a cultivation container having partitioned spaces created by erecting multiple partition plates on a perforated board having holes smaller than the shellfish at the bottom is immersed in a water tank, the shellfish are attached to the partition plates, water is supplied to the partitioned spaces, and the shellfish are fed.

[0010] A shellfish cultivation device that solves the above problems comprises a cultivation container for raising shellfish, which has multiple partition plates erected on a perforated board having holes smaller than the shellfish at the bottom to create partitioned spaces, a water tank into which the cultivation container is immersed, and a water supply pipe for supplying water to the partitioned spaces. [Effects of the Invention]

[0011] According to this disclosure, shellfish can be cultivated efficiently. [Brief explanation of the drawing]

[0012] [Figure 1] This is an explanatory diagram of a shellfish cultivation apparatus in an embodiment. [Figure 2] This is an explanatory diagram of a breeding container in an embodiment, where (a) is a perspective view, (b) is a frame, and (c) is an explanatory diagram of attaching and detaching a partition plate to the breeding container. [Figure 3] This is an explanatory diagram of the water supply to the breeding container in the embodiment. [Figure 4] This is an explanatory diagram of the water circulation in the embodiment of the breeding system. [Modes for carrying out the invention]

[0013] Below, an embodiment of a shellfish cultivation method and apparatus will be described using Figures 1 to 4. In this embodiment, abalone are cultivated on land in a completely closed, circulating environment.

[0014] As shown in Figure 1, in the shellfish cultivation device A1, the rearing container 10 is immersed in rearing water W1 inside the tank 20. A water supply pipe 30 is positioned above the rearing container 10. As shown in Figure 2(a), the rearing container 10 is composed of a frame 11, side plates 12, and multiple partition plates 13. In this embodiment, the frame 11, side plates 12, and partition plates 13 are made of a hard plate material (PVC plate). The frame 11 uses a perforated board (punching plate) with holes 11h provided at predetermined intervals. These holes 11h are sized so that the juvenile abalone being farmed do not fall off, and are sized so that the juvenile abalone can move around on the frame 11. When rearing juvenile abalone in small groups from the early stages when their shell length is about 2-3 cm, for example, the diameter of the holes 11h is 0.5-1 cm, and they are arranged at intervals of 3-5 cm, which is greater than the shell length of the abalone being reared. When not feeding, the abalone attach themselves to the partition plates 13 that do not have holes. In the partitioned space, the height of the partition plates 13 is greater than the spacing between the partition plates 13, resulting in a higher abalone stocking density per unit area compared to free-range abalone.

[0015] As shown in Figure 2(b), the frame 11 is connected to two side portions 11a and a bottom portion 11b. As shown in Figure 2(c), a side plate 12 is detachably positioned between the two side portions 11a of the frame 11, forming a box-shaped rearing container 10. Furthermore, within the rearing container 10, the sides of a partition plate 13, which is erected relative to the side plate 12, are detachably fixed to the frame 11. Abalone juveniles are adsorbed onto this partition plate 13.

[0016] As shown in Figure 3, breeding water W1 is supplied from the water supply pipe 30 to the breeding container 10 via the water supply holes 31. The water supply holes 31 are located above each partitioned space separated by the side plates 12 and partition plates 13. Breeding water W1 is then supplied to each partitioned space from the water supply holes. The supplied breeding water W1 is distributed to the tank 20 through the holes 11h in the frame 11. The breeding water W1 supplied to the tank 20 is discharged from the discharge pipe 35 located below the tank 20.

[0017] Figure 4 is a conceptual top view of the water tank 20. As shown in Figure 4, an aeration device 32 is provided in this water supply pipe 30. The aeration device 32 performs aeration to send air into the breeding water W1. For example, an air stone or a diffuser is attached, and air is sent from an air pump to send air into the breeding water W1. The breeding water W1 is supplied by a supply device 40 connected to the water supply pipe 30. This supply device 40 includes a calcium chloride supply device, a buffer tank, an electrolysis device, a solid matter removal device, a denitrification device, a biological filtration tank, a pump, and a cooler, similar to the system described in Patent Document 1.

[0018] The calcium chloride supply device supplies calcium chloride as a calcium agent to the buffer tank. The buffer tank is a water storage tank that stores the breeding water.

[0019] The electrolysis device partially oxidizes the pigment (persistent organic matter) to make it easier to remove. The solid matter removal device physically removes solid wastes such as uneaten feed and feces. The denitrification device performs a nitrate treatment in which microorganisms convert nitrate to nitrogen to render it harmless.

[0020] The biological filtration tank performs an ammonia treatment in which harmful ammonia is converted to less toxic nitrate by microorganisms attached to the filter medium, and a dissolved organic matter decomposition treatment for decomposing organic matter. The pump circulates the breeding water. The cooler adjusts the temperature of the breeding water.

[0021] Abalones are bred in each partition space. As described above, aerated water supply and feeding are performed in each partition space. For example, the supplied feed adheres to the side plates 12 and the partition plates 13, or accumulates on the bottom surface portion 11b of the frame body 11. Then, the abalones in each partition space feed in each partition space. Also, the feed (uneaten feed) that has been eaten and has become smaller is discharged from the holes 11h of the frame body 11. The feed that has fallen to the bottom of the water tank 20 is discharged together with the breeding water from the discharge pipe 35.

[0022] (Operation of this embodiment) The partition plates 13, which the abalone adhere to, form each partitioned space, thus increasing the breeding area.

[0023] (Effects of this embodiment) (1) In this embodiment, the rearing container 10 is composed of a rigid frame 11, side plates 12, and partition plates 13. Compared to free-range rearing, this increases the rearing area by causing the abalone to adhere to the partition plates 13, thereby enabling high-density farming. In this case, since the abalone are reared in each partitioned space separated by the partition plates 13, the area in which they can roam is limited. This reduces the competitive conditions among individual abalone, thereby equalizing feeding opportunities. As a result, the mortality rate decreases, and shell length grows while maintaining a certain degree of body fat. Furthermore, the growth deviation between individuals is reduced, and the growth disparity between individuals can be mitigated. (2) In this embodiment, a perforated board is used for the bottom surface 11b of the frame 11. This allows abalone to wander around the bottom surface 11b and feed. Furthermore, the clogging of the holes 11h can be suppressed as the abalone wander around in search of food.

[0024] (3) In this embodiment, the bottom surface 11b is made of a perforated board having holes 11h. This allows powdery leftover food and feces to be discharged from each partitioned space through the holes 11h. Furthermore, as abalone wander around the bottom surface 11b in search of food, the accumulation of dirt on the bottom surface 11b can be suppressed.

[0025] (4) In this embodiment, the water supply hole 31 of the water supply pipe 30 is positioned above each partitioned space separated by the side plate 12 and the partition plate 13. This allows the rearing water W1 to be supplied to each partitioned space. The supplied rearing water W1 is then discharged from the hole 11h of the frame 11 and circulated by the supply device 40 to maintain water quality.

[0026] (5) In this embodiment, the side plates 12 and partition plates 13 are detachably arranged on the frame 11. Therefore, while the abalone are adhering to the side plates 12 and partition plates 13, they can be removed from the frame 11 to change their arrangement, spacing, and the frame 11 itself. (6) In this embodiment, turbulence can be generated by performing aeration when supplying water, and dirt can be discharged by the water flow.

[0027] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0028] In the above embodiment, the shellfish cultivation device was applied to abalone farming. However, it is not limited to abalone as long as it is a shellfish that grows through feeding. In the above embodiment, the rearing container 10 is equipped with two partition plates 13, but the number of partition plates 13 is not limited. Also, the spacing between the partition plates 13 (environmental conditions) may be changed (increased) according to the growth of different abalone. For example, a monitoring device acquires an image of the partition space taken from above and measures the shell length and activity level of the abalone. Then, this monitoring device outputs change information to the administrator terminal, suggesting changes to environmental conditions such as spacing according to the activity level. For example, if the monitoring device measures the size of the abalone (e.g., shell length) and the size of the abalone exceeds a standard value relative to the size of the partition space (e.g., volume or side length), it outputs a warning message. Alternatively, the device may measure the distance traveled by the abalone within the partition space over a predetermined period of time as an indicator of activity level, and output a warning message if the activity level falls below a standard value.

[0029] In the above embodiment, the side panel 12 may be formed from a perforated board. In the above embodiment, an aeration device 32 is provided in the water supply pipe 30. It is sufficient if aeration can be achieved in the partitioned space when water is supplied. For example, a shower pipe may be provided in the water supply hole 31 to finely disperse the water flow, thereby increasing the contact area between water and air and performing aeration.

[0030] In the above embodiment, perforated board is used for the side portion 11a and the bottom portion 11b of the frame 11. It is sufficient that there are holes 11h in at least the bottom portion 11b. [Explanation of Symbols]

[0031] A1... Shellfish growing device, 10... Breeding container, 11... Frame, 11a... Side part, 11b... Bottom part, 11h... Hole, 12... Side plate, 13... Partition plate, 30... Water supply pipe, 31... Water supply hole, 32... Aeration device, 35... Discharge pipe, 40... Supply device.

Claims

1. A method for raising shellfish using a shellfish cultivation device, A breeding container, in which multiple partition plates are erected on a perforated board with holes smaller than those of shellfish at the bottom to create partitioned spaces, is immersed in a tank of water. The shellfish are attached to the partition plate, and water is supplied to the partition space. A method for cultivating shellfish, characterized by feeding the aforementioned shellfish.

2. The method for cultivating shellfish according to claim 1, characterized in that the sides of the erected partition plate are joined with the perforated board.

3. The method for cultivating shellfish according to claim 1 or 2, characterized in that aeration is performed in the partitioned space into which water is supplied.

4. The monitoring device photographs the shellfish in the partitioned space and measures their activity level. The method for cultivating shellfish according to claim 1, wherein information on changes in the environmental conditions of the partitioned space is output according to the activity state.

5. A shellfish rearing device for raising shellfish, A breeding container having a perforated board with holes smaller than those of shellfish at the bottom, to which multiple partition plates are erected to create partitioned spaces, A tank into which the aforementioned breeding container is immersed, A shellfish cultivation apparatus characterized by comprising a water supply pipe for supplying water to the partitioned space.

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