Shellfish farming systems and farming methods

Abstract

To provide a shellfish culture system and a culture method capable of reducing use rearing water and an energy cost and adjusting and maintaining a rearing environment to be optimal for growing of the shellfish, thereby shortening a manufacturing period and greatly reducing a running cost of an entire system.SOLUTION: A shellfish culture system 1 includes: a rearing tank 2 accommodating rearing water and the shellfish reared; a rearing water temperature adjusting tank 3 supplying the rearing water to the rearing tank; and an organism filtration tank 4; causes the rearing water to sequentially circulate in the rearing tank, a rearing water temperature adjusting tank, and the organism filtration tank; and takes in new rearing water from the outside. By a rearing water take-in mechanism of the rearing water temperature adjusting tank, 10 to 30% of new rearing water per one hour with respect to a total water amount of each water amount of the rearing tank, the rearing water temperature adjusting tank, and the organism filtration tank is taken in, and two to three times the total water amount per one hour is circulated.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a shellfish farming system and a farming method, and more particularly to a shellfish farming system and a farming method that can optimally maintain the breeding environment of shellfish and suppress the breeding cost.

Background Art

[0002] Currently, the land-based farming of seafood is being carried out throughout the country. On the other hand, shellfish, especially abalone, have a lower homeostasis ability compared to other fish and are vulnerable to changes in water quality. Therefore, the main breeding method is seawater flooding, and fully closed-loop farming has been considered difficult. In addition, since shellfish grow more slowly than ordinary seafood, there is also a problem of high production costs in land-based farming.

[0003] Therefore, hitherto, techniques for cultivating abalone at low cost by using specific feeds as materials for aquaculture feeds have been proposed (Patent Documents 1 to 3). In the proposal of Patent Document 1, it has been proposed to use food ingredients that are usually discarded as aquaculture feeds. In Patent Documents 2 and 3, proposals have been made to install an algae cultivation device in the system to purify the aquaculture water with the algae and use the algae as feeds.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Production costs in shellfish farming mainly consist of equipment costs, labor costs, and running costs, with electricity costs for water pumping accounting for a particularly large proportion. Therefore, as described in Patent Documents 1-3, using specific feeds does not provide a fundamental solution to reduce production costs, and from a cost-effectiveness perspective, the development of a system that reduces production costs beyond the current level is desired.

[0006] This invention has been made in view of the above circumstances, and aims to provide a shellfish farming system and method that can shorten the production period and significantly reduce the overall running cost of the system by reducing the cost of water and energy used for rearing, and by adjusting and maintaining the rearing environment to be optimal for the growth of shellfish. [Means for solving the problem]

[0007] The shellfish farming system and farming method of the present invention were made to solve the above technical problems and are characterized by the following:

[0008] Firstly, the shellfish farming system of the present invention includes rearing water and rearing tanks for housing the shellfish to be reared. A breeding water temperature control tank for supplying the breeding water to the breeding tank, and Including a biological filtration tank, A shellfish farming system that sequentially circulates the rearing water through the rearing tank, the rearing water temperature control tank, and the biological filtration tank, and also takes in new rearing water from the outside, The water volumes of the breeding water temperature control tank and the biological filtration tank are in a ratio of 15 to 30 when the water volume of the breeding tank is set to 100. The aforementioned rearing tank has a wastewater discharge mechanism for discharging wastewater, The aforementioned breeding water temperature control tank has a breeding water intake mechanism that takes in new breeding water from the outside, The rearing water intake mechanism of the aforementioned rearing water temperature control tank takes in 10-30% of the total volume of water in the rearing tank, rearing water temperature control tank, and biological filtration tank per hour, The system is characterized by circulating 2 to 3 times the total volume of water per hour. Secondly, the shellfish farming system of the first invention is characterized in that a physical filtration device is provided between the rearing tank and the rearing water temperature control tank. Thirdly, in the shellfish farming system of the first or second invention described above, the temperature of the rearing water is adjusted to 15-25°C by a temperature control device provided in the rearing water temperature control tank. Fourth, in the shellfish farming system of the first to third inventions described above, the shellfish is abalone, and the rearing water is seawater or saline water adjusted to contain seawater components. Fifth, the shellfish cultivation method of the present invention includes rearing water and a rearing tank for housing the shellfish to be reared. A breeding water temperature control tank for supplying the breeding water to the breeding tank, and Including a biological filtration tank, A method of cultivating shellfish using a shellfish cultivation system that sequentially circulates the cultivation water through the aforementioned cultivation tank, cultivation water temperature control tank, and biological filtration tank, while also taking in new cultivation water from an external source, The water volumes of the breeding water temperature control tank and the biological filtration tank are in a ratio of 15 to 30 when the water volume of the breeding tank is set to 100. In the aforementioned breeding tank, wastewater is discharged, In the aforementioned breeding water temperature control tank, 10-30% of the total water volume of the breeding tank, the breeding water temperature control tank, and the biological filtration tank is replaced with new breeding water per hour. This method is characterized by circulating 2 to 3 times the total amount of water used for rearing per hour. [Effects of the Invention]

[0009] According to the shellfish farming system and method of the present invention, it is possible to reduce the cost of rearing water and energy, and to adjust and maintain the rearing environment to be optimal for the growth of shellfish, thereby shortening the production period and significantly reducing the running cost of the entire system, making it possible to improve the efficiency of production and save energy. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic configuration diagram showing an embodiment of the shellfish farming system of the present invention. [Figure 2] This is a test-scale actual photo of the shellfish farming system of the embodiment in FIG. 1. [Figure 3] This is a test-scale actual photo of the shellfish farming system shown in FIG. 2 as viewed from another direction.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the shellfish farming system according to the present invention will be described in detail based on the drawings. FIG. 1 is a schematic configuration diagram of an embodiment of the shellfish farming system according to the present invention. The shellfish farming system 1 of this embodiment includes a breeding tank 2 for accommodating breeding water and shellfish to be bred, a breeding water temperature control tank 3, and a biological filtration tank 4.

[0012] Examples of the shellfish that can be bred in the shellfish farming system 1 of this embodiment include herbivorous abalones and turban shells belonging to the Gastropoda class of the Mollusca phylum that can generally be terrestrially farmed using seawater or fresh water. Among these, abalones can be preferably bred. When breeding marine shellfish, seawater or brine adjusted to seawater components is used as the breeding water. In the following embodiments, a farming system for breeding abalones using seawater as the breeding water will be described.

[0013] (Breeding Tank) The breeding tank 2 used in this embodiment is suitable for land-based farming equipment that can stably breed the abalones to be bred without stress and can circulate and drain seawater (breeding water).

[0014] The breeding tank 2 is provided with a sewage discharge mechanism 21, and sewage containing residues such as excrement of abalones and feed generated in the breeding tank 2 is discharged. As the sewage discharge mechanism 21, for example, a configuration in which it is discharged by overflow from a discharge port provided at a predetermined height in the tank, or a configuration in which sewage is discharged from a discharge port provided at the bottom for sedimented solids and the like accumulated at the bottom of the breeding tank 2 can be adopted.

[0015] The amount of abalone cultured in the culture tank 2 can be set according to the growth stage and individual size of the individuals. For example, when the shipping size is about 80 mm in shell length, the bottom area of the culture tank 2 is 1 m 2 A culture amount in the range of 6 to 10 kg per square meter is considered, and the number of cultured individuals in this case is considered to be 100 to 150. In addition, feeding of abalone is carried out in the culture tank 2, but the feeding amount is up to a maximum of 100 g / day per square meter of the bottom area of the culture tank 2 2 is considered to be given.

[0016] (Rearing water temperature control tank) The rearing water temperature control tank 3 is a water tank for adjusting the seawater introduced into the culture tank 2 to an optimal state. It circulates and introduces the seawater of the culture tank 2, adjusts the water quality and temperature, and then circulates it again.

[0017] The rearing water temperature control tank 3 has a rearing water intake mechanism 31 for taking in new seawater from the outside, adjusts the water quality and temperature of the new seawater, and supplies it to the culture tank 2. That is, the rearing water temperature control tank 3 constitutes a semi-circulation system with the circulated water from the culture tank 2 and the new seawater taken in from the outside. In addition, the rearing water intake mechanism 31 is provided with a flow meter for monitoring the inflow amount per predetermined time and a valve for controlling the inflow amount.

[0018] In the rearing water temperature control tank 3, in order to adjust the circulated seawater from the culture tank 2 and the new seawater taken in from the outside to seawater optimal for rearing, a foam treatment device 32 for separating and removing fine solids and a temperature adjustment device 33 for adjusting the temperature of the seawater are provided.

[0019] (Foam treatment device) The foam treatment device 32 is a device provided for removing foreign substances and generated foam contained in the new seawater taken in from the outside. A water tank for foam removal treatment can be provided in the rearing water temperature control tank 3, and the foam treatment device 32 can be arranged in this tank.

[0020] (Temperature adjustment device) The temperature control device 33 is provided to heat and cool the circulating seawater and newly introduced seawater to a predetermined temperature, and a commonly known temperature control device can be used. Specifically, a submersible type of heating and cooling chiller is preferably used from the viewpoint of ease of installation. In addition, the rearing water temperature control tank 3 is provided with a discharge mechanism 34 for discharging wastewater containing foreign matter and other substances removed by the foam treatment device 32.

[0021] In this embodiment, the volume of water in the rearing water temperature control layer 3 is 15 to 30 times the volume of water in the rearing tank 2, where 100 is the volume. For example, if the volume of water in the rearing tank 2 is 1000L, the volume of water in the rearing water temperature control layer 3 will be in the range of 150 to 300L.

[0022] (biological filtration tank) In the shellfish farming system 1 of this embodiment, a biological filtration tank 4, into which a biological filter material 41 has been introduced, is provided downstream of the rearing water temperature control tank 3, that is, between the rearing water temperature control tank 3 and the rearing tank 2.

[0023] The biological filter material 41 is a filter material that can accommodate bacteria that decompose nitrogen compounds such as ammonia in seawater generated by abalone excrement and leftover food. The bacteria that colonize the biological filter material 41 consume the bacteria, thereby continuously improving the water quality of the seawater. It is also preferable that the biological filter material 41 itself has a pH adjustment function. By providing the biological filter tank 4, it is possible to improve the survival rate and growth of the abalone being raised.

[0024] The volume of water in the biological filtration tank 4 is in the range of 15 to 30 when the volume of water in the rearing tank 2 is set to 100, taking into consideration the amount of seawater that passes through and the efficient removal capacity of harmful components by the biological filter material 41. For example, when the volume of water in the rearing tank is 1000L, the volume of water in the biological filtration tank 4 is in the range of 150 to 300L.

[0025] Furthermore, the amount of biological filter material 41 introduced relative to the above water volume is typically about half the volume of water in the biological filter tank 4. That is, if the water volume of the biological filter tank 4 is 150L, ​​then approximately 75L of biological filter material 41 should be considered.

[0026] (Circulation pump) In the shellfish farming system 1 of this embodiment, the rearing tank 2 and the rearing water temperature control tank 3 are connected by piping, and a circulation pump 5 and a flow meter 51 for circulating water are provided in the piping. The operation of the circulation pump 5 is controlled so that the seawater in the system is always circulated under predetermined conditions.

[0027] In the shellfish farming system 1 of this embodiment, in addition to the basic configuration described above, a physical filtration device 6 is provided. The physical filtration device 6 consists of a filter for removing abalone excrement, leftover feed, etc. that could not be removed by the wastewater discharge mechanism 21 of the rearing tank 2, and can be installed inside the rearing tank 2, between the rearing tank 2 and the rearing water temperature control tank 3, or inside the rearing water temperature control tank 3. Multiple physical filtration devices 6 can also be provided. Specific examples of physical filtration devices 6 include a sedimentation tank, a drum filter, and a cyclone-type screen filter.

[0028] In the shellfish farming system 1 of this embodiment, the circulation of seawater to the rearing water temperature control tank 3, the biological filtration tank 4, and the rearing tank 2 may be carried out by sequential overflow using the height difference of the installation of each tank, as shown in Figure 1, or a separate pump may be installed to circulate the water.

[0029] According to the shellfish farming system 1 of this embodiment with the above configuration, the construction cost of the system can be reduced, and the rearing environment can be adjusted and maintained to be suitable for the growth of abalone.

[0030] In the shellfish farming system 1 of the above embodiment, new seawater is usually introduced into the rearing water temperature control tank 3 by pumping it from a separate tank prepared for new seawater. However, the energy cost for pumping water usually accounts for a large portion of the energy cost associated with the operation of the system. On the other hand, if the amount of new seawater introduced is severely restricted, the water quality of the circulating seawater deteriorates, which reduces the survival rate of abalone. Therefore, in this invention, in order to maintain good water quality suitable for farmed abalone while minimizing the energy cost of operating the system, the amount of new seawater introduced into the rearing water temperature control tank 3 and the amount of seawater circulated within the system are specified.

[0031] In this embodiment, the amount of seawater newly added is in the range of 10-30% per hour of the total volume of water in the rearing tank 2, the rearing water temperature control layer 3, and the biological filtration tank 4. For example, in a system where the volume of water in the rearing tank 2 is 1000L, the volume of water in the rearing water temperature control layer 3 is 150L, ​​and the volume of water in the biological filtration tank 4 is 150L, ​​the total volume of water is 1300L, so the amount of new seawater taken in per hour is 130-390L.

[0032] Furthermore, the wastewater discharge mechanism 21 of the rearing tank 2 and the drainage mechanism 34 of the rearing water temperature control tank 3 discharge approximately the same amount of wastewater as the newly introduced seawater, thus maintaining a nearly constant amount of circulating seawater.

[0033] Furthermore, the amount of seawater circulated in the shellfish farming system 1 of this embodiment is 2 to 3 times the total volume of water in the rearing tank 2, the rearing water temperature control layer 3, and the biological filtration tank 4 per hour. For example, if the total volume of water in the rearing tank 2, the rearing water temperature control layer 3, and the biological filtration tank 4 is 1300L, the amount of circulated water per hour is 2600 to 3900L.

[0034] Furthermore, it is preferable to adjust the temperature of the circulating seawater to 15-25°C using the temperature control device 33 of the rearing water temperature control tank 3. In addition, based on the relationship between the ambient temperature and the temperature of the circulating water, it is preferable to adjust the temperature to be below 25°C in the summer (June-September) and above 15°C in the winter (December-March).

[0035] By setting the amount of new seawater taken in and the amount of seawater circulated within the system to the above conditions, the circulating seawater is properly treated in the biological filtration tank 4, supplying seawater with optimal conditions to the rearing tank 2 where the abalone are kept. In addition, the energy costs associated with the operation of the system can be reduced.

[0036] Although the shellfish farming system 1 of the present invention has been described above based on embodiments, the shellfish farming system of the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention.

[0037] For example, although the above embodiment was described as an abalone farming system using seawater as rearing water, it can also be applied to the farming of other marine herbivorous shellfish using seawater, or to the farming of herbivorous shellfish using freshwater as rearing water.

[0038] Furthermore, the shellfish farming method of the present invention is a farming method that uses the shellfish farming system 1 of the present invention described above, and specifically includes a rearing tank 2 that houses rearing water and shellfish to be reared, a rearing water temperature control tank 3 that supplies rearing water to the rearing tank 2, and a biological filtration tank 4, and is a farming method that uses a shellfish farming system that sequentially circulates rearing water to the rearing tank 2, the rearing water temperature control tank 3, and the biological filtration tank 4, while also taking in new rearing water from the outside.

[0039] Then, the water volumes of the rearing water temperature control tank 3 and the biological filtration tank 4 are adjusted to a ratio of 15 to 30, where the water volume of rearing tank 2 is set to 100. In addition, wastewater is discharged from rearing tank 2, and new rearing water is taken in from the outside into the rearing water temperature control tank 3.

[0040] Furthermore, the breeding water temperature control tank 3 takes in 10-30% of the total volume of water in the breeding tank 2, the breeding water temperature control tank 3, and the biological filtration tank 4 per hour, and circulates 2-3 times the total volume of breeding water per hour.

[0041] According to the shellfish farming method of the present invention described above, it is possible to efficiently and reliably grow the shellfish being farmed, and to stably supply the desired shellfish to the market. [Examples]

[0042] The shellfish farming system of the present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following examples.

[0043] Based on the shellfish farming system configured in Figure 1, the following tanks and equipment were used to construct the actual medium-scale test tank shellfish farming system shown in Figures 2 and 3.

[0044] Breeding tank (1-ton rectangular tank: internal dimensions: width / 1800, depth / 900, height / 710 (mm), volume: 1150L, ​​water volume: 570L (water depth 350mm)) At the time of storage: Abalone (shell length 35 mm, 500 individuals)

[0045] Aquarium water temperature control tank (internal dimensions: width / 630, depth / 430, height / 370 (mm), volume: 100L, water volume: 95L (water depth 350mm), equipped with foam treatment device and temperature control device) Foam treatment device (internal foam separation device: H&S HS-850 protein skimmer) Temperature control device (Temperature control chiller: Lacy FZ-601HPN immersion cooler (cooling and heating))

[0046] Biological filter tank (Internal dimensions: Width / 740, Depth / 450, Height / 450 (mm), Volume: 150L, ​​Water volume: 135L (Water depth 405mm)) Biological filter media (Powerhouse Basic Hard Type L, manufactured by Taiheiyo Cement) 70L used.

[0047] Circulation pump (circulation throughout the tank): (Reisy RMD-551 magnetic pump; circulation flow rate: maximum 40 L / min (30-35 L / min during testing); a flow meter was installed to monitor the circulation flow rate.) Physical filtration system (Sunhope AKY38840 cyclone-type screen filter)

[0048] <Examples> Regarding the shellfish farming system 1 described above, the amount of newly added seawater was adjusted to supply 80L per hour, which is 10% of the total water volume (800L) of the rearing tank 2, rearing water temperature control tank 3, and biological filtration tank 4. Approximately the same amount of circulating seawater as the added seawater was discharged through the overflow from rearing tank 2 and the discharge mechanism 34 from rearing water temperature control tank 3. Furthermore, the operating rate of the circulation pump 5 was adjusted to circulate the circulating seawater within the system to 2000L per hour, which is 2.5 times the total water volume (800L) of the rearing tank 2, rearing water temperature control tank 3, and biological filtration tank.

[0049] <Comparative Example> As a comparative example, in the shellfish farming system 1 of the above embodiment, the operation of the circulation pump 5 was stopped to prevent the circulation of seawater, and new seawater was continuously supplied at a rate of 700 L per hour to create a continuous flow system.

[0050] Abalone were farmed under the conditions of the above-described examples and comparative examples, and their condition was observed every 30 days from mid-December to mid-March of the following year. The total energy consumption of the system was also confirmed from late July to mid-March of the following year. The detailed operating conditions and results for the examples and comparative examples are shown below.

[0051] <Energy consumption of the example (semi-circulation)> (calculated value from measurement results) Cooling equipment was used during the summer months (June to September), and heating equipment was used during the winter months (December to March) (assuming a cost of 22 yen / kWh). (1) Use the cooling system (raw water temperature -3°C) for 4 months during the summer, with a daily operating rate of 50%. Electricity usage per hour / electricity cost = 0.5 kWh / 11.00 yen, 4 months = 1,440 kWh / 31,680 yen (2) Use the heating device (raw water temperature + 3°C) for 4 months during the winter, with a daily operating rate of 40%. Electricity usage per hour / electricity cost = 0.4 kWh / 8.80 yen, 4 months = 1,152 kWh / 25,344 yen (3) Foam separation device (continuous operation) Electricity usage per hour / electricity cost = 0.04 kWh / 0.88 yen, annually = 350 kWh / 7,700 yen (4) Circulation pump within the biological filter tank (approximately 15 L / min, constantly running) from the biological filter tank (outlet) to the biological filter tank (inlet) Electricity usage per hour / electricity cost = 0.04 kWh / 0.88 yen, annually = 350 kWh / 7,700 yen (5) Circulation pump from the breeding tank to the foam separation tank (approximately 40 L / min, constantly running) Electricity usage per hour / electricity cost = 0.15 kWh / 3.30 yen, annual cost = 1,300 kWh / 28,600 yen Total electricity consumption: (1) + (2) + (3) + (4) + (5) = 4,592 kWh per year Total electricity costs: (1) + (2) + (3) + (4) + (5) = approximately 100,000 yen per year

[0052] <Energy consumption of a comparative example (continuous flow)> (Calculated value from actual results) (1) The cooling system (cooling raw water to -3°C) is used for 4 months during the summer, with a daily operating rate of 70%. Electricity usage per hour / electricity cost = 7 kWh / 1,540 yen, 4 months = 20,160 kWh / 443,520 yen (2) Use the heating device (raw water temperature + 3°C) for 4 months during the winter, with a daily operating rate of 50%. Electricity usage per hour / electricity cost = 3.5 kWh / 770 yen, 4 months = 10,080 kWh / 221,760 yen Total electricity consumption: (1) + (2) = 30,240 kWh per year Total electricity costs: (1) + (2) = approximately 660,000 yen per year

[0053] From the results above, it was confirmed that the total energy consumption (electricity used) of the system was approximately 6.6 times higher under the conditions of the comparative example than under the conditions of the example. On the other hand, it was confirmed that the growth condition of the abalone from mid-December to mid-March of the following year was very good in both the example and the comparative example.

[0054] From these findings, it has been confirmed that the shellfish farming system of the present invention allows for adjustment and maintenance of rearing conditions to optimize growth, significantly reduces the overall running costs of the system, and enables increased production efficiency and energy conservation. [Explanation of Symbols]

[0055] 1. Shellfish farming system 2 breeding tanks 21 Wastewater discharge mechanism 3 Breeding water temperature control tank 31. Water intake mechanism for rearing 32 Foam treatment device 33 Temperature adjustment device 34 Ejection mechanism 4 Biological filtration tank 41 Biological filter media 5. Circulation pump 51 Flow meter for circulating water 6 Physical filtration device

Claims

1. Rearing water and rearing tanks for housing the shellfish to be reared, A breeding water temperature control tank for supplying the breeding water to the breeding tank, and Including a biological filtration tank, A shellfish farming system that sequentially circulates the rearing water through the rearing tank, the rearing water temperature control tank, and the biological filtration tank, and also takes in new rearing water from the outside, The water volume of the breeding water temperature control tank and the biological filtration tank is such that the water volume ratio is 15 to 30 when the water volume of the breeding tank is set to 100. The aforementioned rearing tank has a wastewater discharge mechanism for discharging wastewater, The aforementioned breeding water temperature control tank has a breeding water intake mechanism that takes in new breeding water from the outside, The rearing water intake mechanism of the aforementioned rearing water temperature control tank takes in 10-30% of the total volume of water in the rearing tank, rearing water temperature control tank, and biological filtration tank per hour, A shellfish farming system characterized by circulating two to three times the total volume of water per hour.

2. The shellfish farming system according to claim 1, characterized in that a physical filtration device is provided between the rearing tank and the rearing water temperature control tank.

3. The shellfish farming system according to claim 1, characterized in that the temperature of the rearing water is adjusted to 15 to 25°C by a temperature control device provided in the rearing water temperature control tank.

4. The shellfish farming system according to claim 1, characterized in that the shellfish is abalone and the rearing water is seawater or saline water adjusted to contain seawater components.

5. Rearing water and rearing tanks for housing the shellfish to be reared, A breeding water temperature control tank for supplying the breeding water to the breeding tank, and Including a biological filtration tank, A method of cultivating shellfish using a shellfish cultivation system that sequentially circulates the cultivation water through the aforementioned cultivation tank, cultivation water temperature control tank, and biological filtration tank, while also taking in new cultivation water from an external source, The water volume of the breeding water temperature control tank and the biological filtration tank is such that the water volume ratio is 15 to 30 when the water volume of the breeding tank is set to 100. In the aforementioned breeding tank, wastewater is discharged, In the aforementioned rearing water temperature control tank, 10-30% of the total volume of water in the rearing tank, the rearing water temperature control tank, and the biological filtration tank is replaced with new rearing water per hour. A method for cultivating shellfish, characterized by circulating two to three times the total volume of water per hour.

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