JP6749691B2 - Aquaculture device, aquaculture system and aquaculture method - Google Patents

Description

The present invention relates to an aquaculture device, aquaculture system, and aquaculture method for stimulating aquatic products with ultrasonic waves and ultrasonic waves in order to improve survival rate and yield of aquatic products.

BACKGROUND ART Conventionally, various kinds of aquatic products such as fish, shellfish and shellfish have been produced by aquaculture. On the other hand, the world population is expected to reach 11 billion by 2100, and one of the major challenges of the 22nd century is food shortage. Therefore, stable production of fish proteins obtained from aquaculture is an important issue, and a large increase in food production is expected. In Asia, consumption of marine products has increased in the last 30 years, and Japan has the highest per capita consumption of marine products in a country with a population of over 50 million. However, up to now, the improvement of the method of increasing the production of marine products in aquaculture was mainly due to the development of bait, improvement of water temperature and flow, gene recombination, and virus countermeasures, and it was not possible to expect a significant improvement in productivity. ..

Therefore, several different methods have been proposed as methods of increasing production to further improve the productivity of aquaculture. For example, in Patent Document 1, a solar cell is provided on the upper surface of a buoy floating in a cage in the sea, the output of the solar cell is supplied to the storage battery, and the output of the storage battery is connected to an ultrasonic oscillator in contact with water. An ultrasonic transmitter for growing fish and shellfish is disclosed. Electric power generated by a solar cell is accumulated in this storage battery, and the electric power oscillates a weak ultrasonic wave from the ultrasonic oscillator into water regardless of day or night, thereby promoting the growth of fish and shellfish. Further, the ultrasonic wave oscillating surface in contact with water is covered with copper so that algae and the like are prevented from adhering to the ultrasonic wave oscillating surface of the ultrasonic oscillator by the sterilizing action of copper ions.

Patent Document 2 discloses a method of administering an agent of a compound to an aquatic animal such as a goldfish through ultrasonic waves. This method is intended to prevent diseases of farmed fish and prevent infection by sonication for a short time.For example, when a viral disease is treated with an immersion vaccine, a vaccine is added. In a beaker, ultrasonic waves having an intensity of 1 MHz and 1.7 W/cm ² are emitted for 10 to 15 minutes. As a result, when the gonadotropin-releasing hormone analog is administered via water, the absorption of the gonadotropin-releasing hormone analog through the skin of fish can be significantly improved.

In the method for cultivating fish and shellfish of Patent Document 3, ultrasonic waves of 10 to 30 MHz are applied to the fish and shellfish to cultivate the fish by generating micro bubbles of 20 μm or less using a swirl type bubble generator. It is disclosed that this improves the growth rate and feed efficiency of cultured seafood.

Patent Document 4 discloses a disease treatment apparatus and method for preventing illness and preventing infection of cultured fish by ultrasonic treatment for a short time, and particularly radiates ultrasonic waves to cultured fish in highly concentrated dissolved oxygen water. In addition, the vaccine treatment is performed. This allows the cultured fish to efficiently absorb the immersion vaccine for preventing viral diseases and improve the mortality rate.

Further, Patent Document 5 uses a plurality of piezoelectric vibrators as ultrasonic vibrators, and includes a container movably positioned on the surface of water on which aquatic products are cultivated or underwater, and a plurality of ultrasonic vibrations attached to the container. Disclosed is an aquaculture device having a child, each ultrasonic transducer having a different ultrasonic irradiation direction, and a container radiating ultrasonic waves to a marine product while being moved while moving on the water surface or in water. Furthermore, a method of aquaculture for cultivating aquatic products using an aquarium having a side surface made of a material having an acoustic impedance of 3 MRayls or more and 50 MRayls or less, the aquatic aquaculture having an ultrasonic transducer in a water tank in which water is injected. Disclosed is a method for aquaculture, in which a device is inserted, ultrasonic waves are generated from an ultrasonic transducer, and ultrasonic waves are radiated to marine products in water.

Japanese Patent Laid-Open No. 6-113694 Japanese Patent Publication No. 6-503951 JP-A-2002-119 JP, 2007-215475, A WO2015/159757

In the case of the methods disclosed in Patent Documents 1 to 4 of the background art described above, the ultrasonic generator used does not control by appropriately changing the radiation direction of the ultrasonic wave, and the ultrasonic wave is generated in a large-sized aquarium. There is a problem that irradiation cannot be performed widely and uniformly. Further, in the case of the method disclosed in Patent Document 3, a swirl-type bubble generator is used to generate microbubbles of 20 μm or less, but it is difficult to stably generate an ultrasonic wave of 10 to 30 MHz. is there. There is also a problem that the emission direction of ultrasonic waves cannot be controlled, and ultrasonic waves of 10 MHz or higher are easily attenuated in water containing much oxygen, and it is difficult to maintain the acoustic intensity.

In addition, there is also a method of irradiating sound waves to aquatic products using a low frequency speaker, but in this case, it is fixed in a support rod and immersed in water to generate sound waves, and it is not easy to change the direction of the sound waves. Can not. For this reason, it is difficult to uniformly and widely irradiate the fish in the water tank with sound waves, and it is necessary to install a plurality of sound wave irradiation devices in the water tank, which is inferior in economic efficiency. Furthermore, there is a problem that the effect is small for flounder, shrimp, and shellfish, which are marine products that tend to accumulate at the bottom of ponds and tanks. In addition, since important sonic vibration circuit components are underwater, there is a risk of water infiltration, making inspection and maintenance of the device difficult.

As mentioned above, aquaculture equipment or disease prevention apparatus according to hitherto known sonic or ultrasonic irradiation, and 0.5 m ³ or less of the water tank for the experiment, Ya large aquarium for mass production of 1 to 100 m ³ There are various problems whether it is applied to a sea divided by a pond or a net. For example, when used in fixing the vibrator and equipment on the side surface or the bottom surface of the tank, as shown in FIG. 11, is radiated from the outer surface of the outer case 12 through the acoustic matching layer 22 from the ultrasonic transducer 20 The irradiation direction and range of ultrasonic waves are constant. Further, the acoustic intensity is strong only in the direction in which the ultrasonic transducer 20 faces, and the high-intensity acoustic wave 19 that is still oscillated from the ultrasonic transducer 20 is directly irradiated, and the acoustic intensity is made uniform in the water tank. It is something that cannot be done. In addition, it may not be possible to effectively and uniformly radiate ultrasonic waves to the cultured fish 29 accumulated at the corners and bottom of the aquarium, and the ultrasonic waves may not reach because of the shadow of other accumulated cultured fish. ..

In addition, the ultrasonic waves used in the aquaculture industry that have been reported so far have a frequency of 20 KHz to 100 KHz, a wavelength in water as long as 8 cm to 1.5 cm, and an average diameter of the body of the fish of 10 cm or less. It is not suitable to efficiently increase the production of cultured fish, small-scale seafood of crustaceans, fish eggs and fry by using acoustic wave stimulation.

On the other hand, Patent Document 5 discloses a levitation-type ultrasonic aquaculture apparatus in which two or more ultrasonic transducers are arranged in the container with different arrangement angles. This device can irradiate ultrasonic waves all over the water tank, but it is difficult to irradiate ultrasonic waves with a wide and almost even distribution in the water tank, and the ultrasonic intensity in the water tank varies. The problem remains.

The present invention has been made in view of the problems of the background art described above, and irradiates acoustic waves over a wide range in an aquarium with a device having a simple structure to resist fish, shellfish, and shellfish that are cultivated. It is an object of the present invention to provide an aquaculture apparatus, aquaculture system, and aquaculture method that can improve the power, improve the survival rate, increase the yield, and perform the operation with good reproducibility.

First, the sound wave is usually defined as 20 kHz or less, and the ultrasonic wave is defined as 20 kHz or more. As an example, an ultrasonic wave having a fundamental wave of 1 MHz has a fundamental wavelength of 1 μs and an underwater wavelength of about 1.5 mm. However, by using pulse driving, it is possible to create a sound of 20 kHz or less, which is close to a sound wave. For example, it is considered that an ultrasonic wave having a duty factor of 20% and a pulse repetition frequency (PRF) of 1 kHz (1 ms) shows a reaction equivalent to that of a 1 kHz ultrasonic stimulation for living cells having a slow reaction rate. The reaction speed of living cells is several ms, which is close to the transmission speed of the nervous system, and it is considered that living cells cannot follow at a speed of 1 μs, which is the wavelength of 1 MHz ultrasonic waves, for example. In the present invention, an ultrasonic pulse driving of the acoustic wave.

It is known in the medical community that such stimulation of low intensity pulse ultrasounds (LIPUS) activates proliferation of osteoblasts, which are living cells of bones of animals, and promotes treatment of fractures. Well known. The present invention utilizes this principle for aquaculture of aquatic products.

The present invention is a marine product culture apparatus that irradiates aquaculture that is being cultivated with an acoustic wave that is at least one of a sound wave and an ultrasonic wave. The high-strength acoustic wave is provided on the front surface side, which includes a drive unit that drives the child and an outer case that holds the ultrasonic oscillator and the drive unit, and emits a high-intensity acoustic wave emitted from the ultrasonic oscillator. The aquaculture device is provided with an acoustic wave diffusing layer made of an acoustic wave scattering material for diffusing waves and converting the intensity per unit area into a low intensity acoustic wave weaker than the high intensity acoustic wave to irradiate a wide range.

The ultrasonic oscillator may be a piezoelectric oscillator, and the acoustic wave diffusion layer may be formed of a layer containing gas and foamed resin containing 90% by volume or more of gas. The foam resin is, for example, expanded polystyrene, expanded polyurethane, or expanded rubber.

The acoustic wave scattering material of the acoustic wave diffusion layer of the present invention is composed of a metal net, and the size of the net is λ to λ/10 of the underwater wavelength λ of the ultrasonic wave used.

The acoustic wave diffusion layer is arranged inside the outer case, inside the acoustic matching layer outside the outer case, or outside the outer case.

Furthermore, at least two acoustic matching layers for acoustic matching between the piezoelectric vibrator and fresh water or seawater as a medium are arranged, and the shape of the acoustic matching layer is larger than that of the piezoelectric vibrator. But good. Further, the outer case is provided with the piezoelectric vibrator which is a disc, a ring or a rectangular plate that generates at least two kinds of frequencies, and the fundamental wave frequency of the ultrasonic vibrator is 0.1 MHz. It is in the range of -10 MHz.

It is preferable that the ultrasonic transducer of the aquaculture apparatus uses a piezoelectric material that does not use lead. The ultrasonic wave is a pulse wave, the repetition frequency thereof is 1000 Hz to 0.5 Hz, and the duty factor is 10 to 60%. At least one of these ultrasonic vibrators is arranged on the side surface of the hollow pyramid container. Anything is fine.

Further, it may be a portable electronic device that is detachable or has a sound generation device that generates an audible sound, a feeding sound, or a swimming sound. It is further preferable that a rechargeable battery is provided as a power source , and the drive unit is operable by the battery, and has a waterproof function.

Further, the present invention is provided with the aquaculture device, is capable of accommodating marine products, the aquarium containing seawater or fresh water, and at least one of the water surface and the water of the aquarium, the aquaculture device is provided, Is an aquaculture system provided so that the acoustic wave can be irradiated into the water.

An acoustic wave reflection layer of an acoustic wave reflection material having an acoustic wave reflectance of 90% or more for reflecting and scattering acoustic waves is provided on at least 80% or more of the inner surface of the water tank. Furthermore, the inner or outer surface material of the water tank is preferably made of a foam material which is an organic material containing a gas layer and a gas.

The acoustic wave reflection material is formed of a sheet, at least the front surface or the back surface thereof is covered with an organic film, the thickness is 0.05 to 1.0 mm, and the inner surface is provided with an organic material containing 90% by volume or more of gas. It is a thing. The organic film on the surface of the acoustic wave reflection material is fluororesin, PET, or nylon, and contains a gas layer or expanded polystyrene, expanded polyurethane, or expanded rubber inside.

Further, the aquaculture system may be used while releasing air bubbles having a diameter of 0.01 to 10 mm into the water. Further, the temperature control device capable of setting the temperature of seawater or fresh water in the water tank at 2°C to 30°C is provided.

Further, the present invention is a method for aquaculture using the aquaculture device, wherein the aquaculture device is floated in water in a water tank that can store marine products and contains seawater or freshwater, and the aquaculture device is freely swung to obtain the aquaculture product. In the aquaculture method, the acoustic wave is generated from the aquaculture device and reflected on the wall surface of the aquarium to apply acoustic stimulation to the water in water.

With the aquaculture apparatus, ultrasonic waves having an ultrasonic intensity (Isata) of 20 mW/kg to 1 W/kg are applied to the total weight of the aquatic products in water, and the aquatic products are subjected to acoustic wave stimulation for aquaculture. Is. Further, the aquaculture device irradiates the aquatic product in the water with the acoustic wave continuously or intermittently for 10 to 60 minutes/day, 1 to 7 days/week, and 1 to 50 weeks.

In addition, an audible speaker of the aquaculture device or a mobile phone may be used to generate an acoustic wave of a frequency and intensity that activates the activity of the aquatic product for cultivation. The marine products are fish, eggs of crustaceans, fry and adult fish.

INDUSTRIAL APPLICABILITY The aquaculture apparatus, the aquaculture system and the aquaculture method of the present invention are lightweight and small-sized apparatus, have a simple structure, are inexpensive and safe, and can effectively and effectively spread low-intensity acoustic wave energy in a water tank. The area can be illuminated. As a result, it is possible to efficiently realize a wide range of promotion of blood flow as an effect of ultrasonic stimulation, enhancement of bone components, improvement of growth rate, improvement of survival rate, increase of yield and the like. Particularly, it is considered that blood and lymph, which are important for treatment and prevention of diseases, are mainly produced in bone marrow of fish as well as human body. Therefore, according to the aquaculture device of the present invention, hematopoiesis is particularly high. It is possible to effectively radiate the acoustic wave to the spine having an action.

Further, by using the aquaculture apparatus, aquaculture system and aquaculture method of the present invention, low-intensity acoustic wave stimulation is applied to bones, etc., thereby activating the living body of aquatic products and improving their vitality, improving virus resistance, improving survival rate, etc. Therefore, it is possible to increase the yield of aquaculture that is being cultivated.

It is a schematic diagram of an aquaculture device of a first embodiment of the present invention. It is the schematic of the graph which changed the acoustic wave intensity with time. It is a graph in which the acoustic wave intensity is changed with time and oscillated in a pulse shape, and the output level is changed while the frequency is constant. It is the schematic which shows the aquaculture apparatus of 2nd embodiment of this invention, an ultrasonic beam, and a marine product. It is a third embodiment of this invention, The top view (a) of the state which removed the outer case of the aquaculture apparatus which attached two ultrasonic transducers each having two kinds of different frequencies, and a longitudinal sectional view. (B) It is a schematic diagram. The modification of the acoustic matching layer and the acoustic wave diffusion layer of this invention is shown, The partial cross section figure (a) of the aquaculture apparatus provided with two acoustic matching layers, The acoustic wave diffusion part is provided in the acoustic matching layer. It is a partial cross-sectional view (b) of the aquaculture device. Fig. 6 shows another modified example of the acoustic matching layer and the acoustic wave diffusion layer of the present invention, and is a partial cross-sectional view (a) of an aquaculture device having an acoustic wave diffusion portion in an outer case. FIG. 3 is a partial cross-sectional view (b) of an aquaculture device including a portion, and a partial cross-sectional view (c) of the aquaculture device including another acoustic wave diffusion portion in the acoustic matching layer. Fig. 6 shows another modified example of the acoustic matching layer and the acoustic wave diffusion layer of the present invention, and is a partial cross-sectional view (a) of the aquaculture device having the acoustic wave diffusion portion inside the acoustic wave diffusion layer outside the outer case, Partial cross-sectional view (b) of the aquaculture device provided with another acoustic wave diffusion portion inside the acoustic wave diffusion layer outside the outer case, another acoustic wave diffusion portion inside the acoustic wave diffusion layer outside the outer case It is a partial cross-sectional view (c) of the aquaculture device. It is the schematic which shows the aquaculture system of 4th embodiment of this invention. It is a 5th embodiment of this invention, and is a schematic transverse sectional view (a) and a schematic vertical sectional view (b) which show the aquaculture apparatus of the structure which provided the ultrasonic transducer on the side of a quadrangular pyramid container. It is a schematic diagram which shows the ultrasonic irradiation beam and the cultured fish which are marine products in the conventional marine product apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. An aquaculture apparatus 10 of this embodiment has a basic configuration, includes an outer case 12 having a watertight structure, and a substrate 14 inside thereof. A power source 16 such as a battery and a control circuit 17 which constitute the driving unit 15 are provided on the upper portion. The lead wire 18 is connected to a terminal (not shown) of the substrate 14 and is connected to a terminal (not shown) of the ultrasonic transducer 20. The ultrasonic transducer 20 is attached to the outer case 12 via an acoustic matching layer 22 and a protective film (not shown), and is provided so that high-intensity acoustic waves 19 can be radiated from the surface of the outer case 12.

An acoustic wave diffusion layer 24 made of an acoustic wave scattering material is provided outside the portion of the outer case 12 to which the ultrasonic transducer 20 is attached. The acoustic wave diffusion layer 24 has a large difference from the acoustic impedance of water, and is preferably made of metal wire mesh or resin containing air. The acoustic wave diffusion layer 24, a high intensity acoustic wave 19, the strength per a relatively unit area is controlled to a low intensity acoustic wave 21 of weaker strength than the high intensity acoustic waves 19 are widely diffused irradiation extensively .. The acoustic wave scattering material is composed of, for example, a metal porous material or a metal mesh, and the average value of the voids of the porous material and the mesh size of the mesh of the metal mesh are equal to the underwater wavelength λ of the ultrasonic wave used. On the other hand, λ to λ/10. Further, a foamed resin having low acoustic impedance can also be used. Further, a fixable support base 28 that detachably holds the audio device 26 may be provided on the upper portion of the outer case 12.

The ultrasonic vibrator 20 is a piezoelectric element that vibrates when a voltage is applied and oscillates ultrasonic waves, and uses thickness vibration or spreading vibration. The resonance frequency of the oscillating ultrasonic wave is 0.1 MHz or more and 10 MHz or less. However, the ultrasonic transducer 20 generates not only the frequency component of the fundamental wave but also its harmonics, and these are effectively used. For the piezoelectric element of the ultrasonic oscillator 20, a PZT ceramic oscillator that has a large electromechanical coupling coefficient and is inexpensive and available is selected. Alternatively, a high-performance relaxor piezoelectric single crystal can be used. However, since these lead-based piezoelectric vibrators contain 50% or more of lead oxide, which affects the environment, it is necessary to collect and appropriately process the device if it breaks. Therefore, it is preferable to use a lead-free piezoelectric material such as a ceramic material mainly containing an alkali niobate salt, a crystal, a lithium tantalate single crystal, or a lithium niobate single crystal. The ultrasonic transducer 20 may be provided with an acoustic backing layer (not shown), which is commonly used in a probe of a medical image diagnostic apparatus, and a heat radiation lead, on the surface opposite to the irradiation direction.

As shown in FIG. 1, the method for using the aquaculture apparatus 10 of this embodiment is such that the low-intensity acoustic wave 21 is evenly distributed in a water tank (not shown) containing the cultured fish 29, which is a marine product, as widely as possible. As the irradiation is performed, the intensity is dispersed using the acoustic wave diffusion layer 24, and the reflected waves from the water tank and the water surface are used to perform low-intensity acoustic wave stimulation on the marine product.

The acoustic wave intensity when the aquaculture device 10 is used can be set as appropriate, and for example, as shown in FIG. 2, the intensity may be gradually increased with time, and then gradually decreased. As shown in FIG. 5, irradiation may be performed by oscillating in a pulse shape, gradually increasing the intensity of the acoustic wave, and similarly gradually lowering the intensity. Further, the change in the acoustic wave intensity may be changed by changing the repetition frequency (PRF) of the ultrasonic pulse used or the amplitude may be changed with time. In particular, by changing the oscillating ultrasonic wave as shown in FIG. 3 and changing the output level at a constant frequency, the principle of crystal growth is utilized to have the effect of enhancing the growth of bone or muscle.

In order to control the irradiation range of the low-intensity acoustic wave 21 by the aquaculture apparatus 10, an acoustic lens or the like may be used by utilizing the principle used for the ultrasonic probe of the medical ultrasonic diagnostic apparatus. .. In this case, it is desirable to use acrylic resin or the like having a higher sound velocity than water to form the convex shape. As the ultrasonic wave, it is preferable to use a pulse wave for intermittent irradiation. As the pulse wave, for example, an acoustic wave having a cycle of 0.001 to 2 seconds (a frequency of 0.1 KHz to 0.5 Hz) and a duty factor of 10 to 60% is used. As the waveform of ultrasonic waves, ultrasonic waves of various waveforms such as sine wave, rectangular wave, and triangular wave can be used. However, it is preferable that the PRF has a period close to a cardiac pulse of 0.5 to 2 seconds (2 Hz to 0.5 Hz), and the duty factor of 10 to 50%. A particularly preferable PRF is to use a combination of audible sounds such as music from a cycle of about 1 second (1 Hz) close to the heart rate to a cycle of about 1 ms (1000 Hz) that has been used in promoting fracture treatment. By using the PRF and Duty factor in this range, it is possible to further activate living cells of marine products in a short period of time.

The ultrasonic intensity (Isata) of the low intensity acoustic wave 21 may be 20 mW/kg to 1 W/kg per total weight of the marine product. Below 20 mW/kg, the effects on growth, repair, activation and survival rate related to bone, skin and muscle are extremely small even after 30 weeks or more. Further, if it is 1 W/kg or more, not only may it be harmful to marine products if it is exposed for a long time, but also the size of the device becomes large. Preferably, the acoustic intensity of the aquaculture device 10 is 50 to 300 mW/kg per total weight of the aquatic product.

The aquaculture device 10 may be further provided with a sound wave device such as a speaker that generates an audible sound of 20 to 2000 Hz. Suitable audible sounds are music, feeding sounds, and swimming sounds. Further, the aquaculture apparatus 10 may be provided with functions such as an integrated time meter, a blinking operation display, an alarm sound, a communication function and a video, a camera for confirming an abnormality of a marine product, and a speaker for generating a sound wave.

The acoustic waves emitted from these devices pass through the soft tissues, skin, fat, and muscle inside the marine product, and reach the bone, which is mostly hard tissue, where they are transmitted to the bone, attenuated, and converted into heat energy. It This stimulates the bone and contributes to the expansion of osteoblasts and the like. It is also possible to increase the required amount of exercise and improve the meat quality by feeding sound, swimming sound, etc. emitted from a speaker that emits audible sound, etc., and various uses are possible.

Next, the aquaculture apparatus 30 according to the second embodiment of the present invention. Description will be given based on FIG. 4. Here, the same configurations as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. FIG. 4 is a schematic diagram showing a state where the aquaculture fish 29, which is a marine product, is irradiated with acoustic waves from the aquaculture device 30 of this embodiment. In the structure of the aquaculture device 30 of this embodiment, the ultrasonic transducer 20 is fixed to the inner surface of the outer case 12 via the first acoustic matching layer 31 and the second acoustic matching layer 32. Inside the second acoustic matching layer 32, which is made of an acoustic wave scattering material so as to face the ultrasonic transducer 20, the high intensity acoustic wave is diffused and the low intensity acoustic wave 21 having a weak intensity per unit area is formed. The acoustic wave diffusing unit 34 is provided to convert the light into a large area for uniform irradiation. In this embodiment, the second acoustic matching layer 32 including the acoustic wave diffusing unit 34 constitutes the acoustic wave diffusing layer 36.

Also with the aquaculture device 30 of this embodiment, since the acoustic wave diffusion layer 36 is provided on the front surface from which the high-intensity acoustic wave emitted from the ultrasonic transducer 20 is radiated, other than directly under the ultrasonic transducer 20. It is possible to perform necessary and sufficient acoustic wave stimulation on marine products. Furthermore, because the acoustic wave diffusion layer 36 is inside the outer case 12, the outer surface of the aquaculture device 30 can be made clean.

Next, an aquaculture device 40 according to a third embodiment of the present invention will be described with reference to FIG. Here, the same configurations as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. The aquaculture device 40 of the embodiment shown in FIG. 5 has two pairs of ultrasonic transducers 41 and 42 each having two different frequencies, and is further equipped with a speaker 44 for outputting audible sound or the like. Is. An acoustic wave diffusion layer 48 is provided on the outer surface of the outer case 46 of this device. The acoustic wave diffusion layer 48 is made of a resin material such as an acoustic wave scattering material or a metal mesh, and has therein an acoustic wave diffusion portion made of two pairs of acoustic wave scattering materials corresponding to the ultrasonic transducers 41 and 42, respectively. 49 are provided. The two pairs of acoustic wave diffusion units 49 are set in different predetermined directions.

The acoustic wave diffusion layer 48 controls the high-intensity acoustic wave having strong directivity to scatter/diffuse by changing the material and shape of the acoustic wave diffusion layer 48, and irradiates aquatic products such as cultured fish with the low-intensity acoustic wave weakened in a wide range. can do. Furthermore, by changing the shape, position, and quantity of the acoustic wave diffusing section 49, the high-intensity acoustic wave having a strong directivity can be diffused, and the low-intensity acoustic wave stimulation can be performed on a marine product in a wide range.

Next, a combination example of the ultrasonic transducer, the acoustic matching layer, the outer case, and the acoustic wave diffusion layer used in the aquaculture apparatus of the present invention will be described based on FIGS. 6 to 8. Here, the same configurations as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The aquaculture apparatus 50 shown in FIG. 6(a) uses a ring-shaped piezoelectric vibrator 20, and has a first acoustic matching layer 31 and a second acoustic matching layer 32 whose outer shapes are larger than those of the piezoelectric vibrator 20. The piezoelectric vibrator 20 is attached to the inside of the outer case 12 via the above. In this aquaculture device 50, the first acoustic matching layer 31 or the second acoustic matching layer 32 also serves as an acoustic wave diffusion layer.

The aquaculture device 52 shown in FIG. 6B uses a disk-shaped piezoelectric vibrator 20, and the piezoelectric vibrator 20 has an outer case with an acoustic matching layer 22 having an outer shape equal to that of the piezoelectric vibrator 20. It is attached inside 12. The aquaculture device 52 includes a cavity for the acoustic wave diffusion portion 49 inside the acoustic matching layer 22. Foamed resin or metal may be provided in the cavity.

In the aquaculture device 54 shown in FIG. 7A, the piezoelectric vibrator 20 is placed inside the outer case 12 via the first acoustic matching layer 31 and the second acoustic matching layer 32 having an outer shape larger than that of the piezoelectric vibrator 20. It is installed. The aquaculture device 54 is configured such that a recess, which is the acoustic wave diffusion portion 49, is formed in the outer case 12 in advance, and a plurality of cavities are formed in a state where the second acoustic matching layer 32 is joined. The cavity that is the acoustic wave diffusion portion 49 may be filled with a foamed resin.

Also in the aquaculture device 56 shown in FIG. 7B, the piezoelectric vibrator 20 is placed inside the outer case 12 via the first acoustic matching layer 31 and the second acoustic matching layer 32 whose outer shape is larger than that of the piezoelectric vibrator 20. The acoustic wave diffusing portion 49 is provided with a plurality of cavities of different shapes inside the second acoustic matching layer 32. The cavity may be filled with foamed resin.

In the aquaculture device 58 shown in FIG. 7C as well, the piezoelectric vibrator 20 is placed inside the outer case 12 via the first acoustic matching layer 31 and the second acoustic matching layer 32 whose outer shape is larger than that of the piezoelectric vibrator 20. It is attached, and the wire net 59 which is the acoustic wave diffusion portion 49 is arranged inside the second acoustic matching layer 32.

The aquaculture apparatus 54 shown in FIG. 8A has a piezoelectric vibrator 20 inside the outer case 12 via a first acoustic matching layer 31 and a second acoustic matching layer 32 each having an outer shape larger than that of the piezoelectric vibrator 20. Is attached. The aquatic product aquaculture apparatus 60 is provided with the acoustic wave diffusion layer 24 outside the outer case 12 and a wire net 59 which is the acoustic wave diffusion portion 49 inside thereof.

The aquaculture device 62 shown in FIG. 8B also has the piezoelectric vibrator 20 inside the outer case 12 via the first acoustic matching layer 31 and the second acoustic matching layer 32 having an outer shape larger than that of the piezoelectric vibrator 20. Is attached, the acoustic wave diffusion layer 24 is provided outside the outer case 12, and the resin member 61 that is the acoustic wave diffusion portion 49 is provided inside thereof.

The aquaculture device 64 shown in FIG. 8C is provided with a ring-shaped piezoelectric vibrator 20, and piezoelectric vibration is generated inside the outer case 12 via an acoustic matching layer 22 having an outer shape larger than that of the piezoelectric vibrator 20. The child 20 is attached, and an acoustic wave diffusion layer 24 is provided outside the outer case 12. The acoustic wave diffusing layer 24 is formed with a protrusion 24 a having a Fresnel structure in which resin is projected.

By changing the material, shape, number and arrangement of the acoustic wave scattering material in the acoustic wave diffusion layer 24, the high intensity acoustic wave emitted from the ultrasonic transducer 20 can be easily converted into the low intensity acoustic wave, It becomes possible to radiate ultrasonic waves uniformly over a wide area. For this reason, it is possible to further reduce the number of required ultrasonic transducers 20 without irradiating aquatic products such as cultured fish with acoustic waves of excessive acoustic intensity. When the acoustic wave scattering material in the acoustic wave diffusion layer 24 is a metal, it can be easily produced by using not only ordinary MC processing and press molding but also a three-dimensional molding apparatus. Further, in order to further reduce the cost, the acoustic wave diffusing layer 24 and a part of the acoustic wave diffusing portion 49 made of the acoustic wave scattering material can be manufactured at the same time when the outer case is molded.

Next, the aquaculture system 70 and the aquaculture method according to the fourth embodiment of the present invention. It will be described with reference to FIG. Here, the same members as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted. FIG. 9 illustrates a structure similar to the aquaculture apparatus 10 of the first embodiment in the aquarium 72, in which the aquaculture apparatus 74 including a plurality of ultrasonic transducers 20 having different irradiation directions is levitated or fixed. Then, acoustic wave stimulation is performed on the cultured fish 29 which is a marine product. In the floating aquaculture device 74, the center of gravity of the aquaculture device 74 is adjusted so as to be off-balanced so that the acoustic wave emission surface of the ultrasonic transducer 20 has an inclination of 3 to 30° with respect to the water surface. Is preferred.

As shown in FIG. 9, the method for using the aquaculture system 70 of this embodiment is such that the aquaculture device 74 is floated on the water in the aquarium 72, and high-intensity acoustic waves are radiated from the ultrasonic transducer 20 into the water. The acoustic wave diffusion layer 24 converts the low-intensity acoustic wave 21. The low intensity acoustic wave 21 is applied to the cultured fish 29 which is a marine product as uniformly as possible while effectively utilizing the irregular reflection of the acoustic wave on the bottom surface, the side surface of the aquarium 72 and the water surface.

An acoustic wave reflection layer 76 containing gas is attached to an area of 80% or more of the side surface and the bottom surface which are the inner surface of the water tank 72. The acoustic wave reflection layer 76 is an acoustic wave reflection material made of foamed resin containing 90 to 99% by volume of gas. By using such an acoustic wave reflecting material, 90% or more of the low-intensity acoustic wave 21 can be effectively reflected and the cultured fish 29 can be effectively irradiated. Further, the material of the acoustic wave reflection layer 76 is preferably vinyl chloride resin, PET, EVA, or rubber containing a gas layer inside. It is also possible to use a thin sheet or film, at least the front surface or the back surface of which is covered with an organic film, which has a thickness of 0.05 to 1.0 mm, and whose inner surface contains an organic material containing 90% by volume or more of a gas. I can.

In this embodiment, low-intensity acoustic wave stimulation is applied to aquatic products such as the cultured fish 29 in the water tank 72 having a height from the bottom surface of the water tank 72 to the water surface of 0.1 to 10 m. If the height to the surface of the water is 0.1 m or less, sufficient depth for inserting the device cannot be obtained, and even a small fish cannot have a sufficient depth for inserting the whole body. Further, this is because the effect of the acoustic wave is weakened by the acoustic attenuation when the distance is 10 m or more. The optimum depth is 0.2 to 1.0 m, which makes it easy to float the device and use it.

The ultrasonic wave to be used can be selected at a frequency of 0.1 to 10 MHz, but 0.1 to 2 MHz is suitable for transmitting acoustic wave power to the bone located at a depth of 10 cm or more from the surface of the aquatic product. When stimulating bones or muscles of 3 cm or less, fish eggs, etc., 2 to 10 MHz is suitable. More preferably, these frequencies are combined and used in series. Further, when the frequency of the ultrasonic transducer used is 10 MHz or more, attenuation in water or marine products containing a lot of air becomes large, and it becomes difficult to obtain a required acoustic wave intensity. The aquarium 72 may have a bottom surface and a side surface made of foamed resin whose acoustic impedance is sufficiently lower than that of seawater or fresh water, and is made of a material such as polystyrene foam or a material having an air layer between the resins, and is used. I can.

The aquaculture device 74 generates acoustic waves at intervals of, for example, 10 to 60 minutes/day, 1 to 7 times/week, and 1 to 50 weeks continuously. The effect of aquaculture is small in a short time of 10 minutes or less, and the effect does not change significantly even if one aquarium 72 is irradiated for 60 minutes or more. The irradiation frequency is 1 to 7 times/week, more preferably 3 to 5 times/week. The irradiation period is effective for several days in the case of small fish and fish eggs, but is preferably a long period of 30 weeks or more. Further, the water tank 72 is provided so that the water temperature can be appropriately set by a temperature control device within a range of 2 to 30°C. This is because the activity of marine products decreases below 2°C, and the survival rate of many marine products decreases below 30°C.

The aquaculture device 74 floating on the water moves to the front, rear, left, and right due to the rocking of the liquid surface of the aquarium 72, or rocks to change the inclination, so that the position of the ultrasonic transducer 20 and the acoustic wave diffusion layer 24 changes. The angle constantly changes, and further, due to the effect of the acoustic wave diffusion layer 24, the low-intensity acoustic wave 21 is uniformly applied to the marine products such as the cultured fish 29. The aquaculture system may be used while releasing air bubbles having a diameter of 0.01 to 10 mm into water.

According to the aquaculture system 70 and the aquaculture method of this embodiment, the aquaculture device 74 having a simple structure is used to freely change the emission direction of the low-intensity acoustic wave 21 and generate an acoustic wave to the aquaculture fish 29 or the like. It is possible to uniformly apply a stimulus, and further, by utilizing diffuse reflection of acoustic waves from the bottom surface, side surfaces, and water surface of the water tank 72, it is possible to widely and almost uniformly apply a low-intensity acoustic wave stimulation to the marine products in the water tank. Further, it is possible to use a large-sized fish box other than the aquarium 72, to increase the number of the aquaculture device 74, or to temporarily fix the aquaculture device 74 to the aquarium 72, or fix it in water. Also has the same effect. Furthermore, by using these devices, it becomes possible to simultaneously and uniformly perform low-intensity acoustic wave stimulation on fish in a large cage. In addition, the aquaculture device 74 can be manufactured in a small shape with a weight of 0.2 to 10 kg, and can be easily transported by women and the elderly. When not in use, it can be easily stored and inspected by taking it out of the aquarium. Can be recharged and cleaned. Therefore, not only is mass production easy, but the maintenance cost for repairing and collecting the product is small, so that the production cost can be significantly reduced. Furthermore, the aquaculture system 70 and the aquaculture method of this embodiment can be used for most aquatic products, and particularly contributes greatly to the improvement of the survival rate of small fish, crustaceans, their fry, and fish eggs.

Further, the acoustic aquaculture system 70 and the aquaculture method of this embodiment may use the aquaculture device 40 having two or more ultrasonic transducers 41 and 42 shown in FIG. By using the aquaculture apparatus 40, it is possible to irradiate the low-intensity acoustic wave 21 widely in two or more different directions with one aquaculture apparatus 40, and the low-intensity acoustic wave 21 is uniformly applied in the aquarium 72. However, the number of required aquaculture equipment 40 can be reduced. Further, the plurality of acoustic wave oscillators 41, 42 may be different in frequency, PRF, Duty factor, and acoustic intensity, and can be set appropriately. Furthermore, you may use the aquaculture apparatus shown in FIGS.

Next, the aquaculture apparatus 80, the aquaculture system, and the aquaculture method according to the fifth embodiment of the present invention. Description will be made with reference to FIG. Here, the same members as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted. As shown in FIGS. 10A and 10B, the aquaculture device 80 includes a hollow outer case 12 having a quadrangular pyramid shape and an upper lid 82, and the upper lid 82 has an O-ring 84 for forming a watertight structure. Equipped with. As the ultrasonic transducer 20, four types of 0.5 MHz, 1.5 MHz, 3.0 MHz, and 8 MHz are attached to each inner side surface of the quadrangular pyramid outer case 12. As the ultrasonic oscillator 20, for example, an alkali niobate material which is a lead-free piezoelectric material is used for 8 MHz, and a normal PZT oscillator is used for the remaining three types. The shape of the ultrasonic transducer 20 is a disc having a diameter of 2 cm.

As the acoustic matching layer 22, a glass plate having a thickness of λ/4 is attached to the ultrasonic transducer 20, and is attached to each of the four inner surfaces of the outer case 12 as shown in FIG. 10. As the driving power source 16, for example, a rechargeable lithium battery is used. A convex acoustic wave diffusion layer 24 having a plurality of cavities and having a diameter of 3 cm and a thickness of 4 mm is provided on the vibrator on the side surface of the aquaculture apparatus 80 using ABS resin. In the acoustic wave diffusion layer 24, a plurality of cavities that are acoustic wave diffusion portions 49 are formed.

The aquaculture apparatus 80 of this embodiment is used by being placed in the aquarium 72 of the aquaculture system shown in FIG. 9, and effectively changes the radiation direction of the low-intensity acoustic wave 21 as in the above-described embodiment. However, the acoustic wave stimulation is uniformly applied to the marine products such as the cultured fish 29. Further, the diffuse reflection of acoustic waves from the bottom surface, side surfaces and water surface of the water tank is utilized to uniformly give low-intensity acoustic wave stimulation to the marine products in the water tank.

The aquaculture apparatus, system and aquaculture method of the present invention are not limited to the above embodiment and can be changed as appropriate. The aquaculture device may be a device that generates acoustic waves while temporarily moving or fixing in a state of being submerged at any depth in water, in addition to a device that floats on the water surface. The structure, material, and shape of the container of the aquaculture device can be freely selected as long as the container can reliably hold and move the ultrasonic vibrator. The size and shape of the aquarium used can also be changed, and the number of ultrasonic transducers in the aquaculture device and the number put in the aquarium can be adjusted appropriately to suit the size and shape of the aquarium, making it suitable for the aquatic product. Set to sound wave intensity. A floating wheel can be used to increase the buoyancy and prevent the device from falling.

In addition, the acoustic wave diffusing section of the present invention is not limited to a void, a foamed resin plate or a metal plate having a hole or a structure or a net, but also a propeller, a windmill, or the like, an umbrella-like shape, or a metal having a slit hole. Even with a different shape, the effect of widely spreading and scattering the ultrasonic beam can be obtained. Further, the ultrasonic transducer may be arranged not only on the bottom surface of the container but also on the side surface portion in the water.

The present invention is one of aquaculture methods using acoustic waves, and may be used in combination with conventionally known devices and methods using microbubbles, bubbles, and virus vaccine administration. Also, the intensity and time of the acoustic wave can be adjusted according to the growth and quantity of the seafood in the aquarium.

Next, examples of the aquaculture apparatus and the aquaculture method of the present invention will be described below. First, as a first example, an experiment was conducted in which the aquaculture apparatus, aquaculture system, and aquaculture method of the present invention were used for aquaculture in a small trout trout as shown in FIG. As the cherry trout, an artificially cultured cherry trout having a fish age of 65 weeks and an average weight of 73 g was used. First, 140 cherry trout that were born from the same parent fish were used, and each group was divided into 7 groups of 20 fish each. These were weighed before the test, and further weighed after 16 weeks. Further, the survival rate was observed almost every day during feeding, and the dead fish were immediately taken out of the aquarium. The water tank was a circular water tank made of fiber reinforced plastic (FRP) having a diameter of 130 cm and a depth of 90 cm, and seawater was added to a depth of 70 cm.

Seven circular aquariums are used, each with a sound wave or music generator with different frequencies, an ultrasonic generator, a device with an acoustic wave diffusion layer, and a tank with or without an acoustic wave reflection layer (water tank inner wall). Ultrasonic waves were applied while levitating. The seawater in the water tank was supplied with 24 tons/day by a pump, and excess seawater was overflowed. Further, compressed air was used to supply 25 m ³ /day of air to the central part of the water tank. As the feed, 1 to 3 g/animal of a normal mixed feed for fish was fed daily in the morning. No agitation of seawater, collection of undigested food, and removal of fish dung were performed.

The aquaculture apparatus used in Example 1 has a hole of about 5 cm in diameter, which is the size of the acoustic matching layer 22, in the outer case 12 which is an aluminum container having a diameter of 33 cm and a depth of 14 cm. .. The apparatus of Example 1 has a basic structure as shown in FIG. 1 in which eight ultrasonic transducers 20 having a diameter of 3 cm are arranged in the outer case 12. As the ultrasonic vibrator 20, a thickness vibration of a PZT-based piezoelectric ceramic (204 material manufactured by Fuji Ceramics Co., Ltd.) ultrasonic vibrator was used. The ultrasonic wave emitting surface of the ultrasonic oscillator 20 has an inclination of 3 to 5° with respect to the water surface. The resonance frequency of the ultrasonic oscillator 20 used was 0.5 MHz. In addition, this aquaculture apparatus 10 generates a pulse ultrasonic wave of 50% duty for 9 minutes and then stops for 1 minute for about 60 minutes per day, 3 times/week for 16 weeks, and continues to stimulate acoustic waves. did. Ultrasonic wave intensity (Isata) is the case of not using the acoustic wave diffusion layer 24 directly below the ultrasonic vibrator at a depth of 30cm was 800 mW / cm ^2, in the case of using an acoustic wave diffusion layer 24 was 80 mW / cm ² ..

As the acoustic wave diffusion layer 24, four stainless steel nets having a mesh opening of 0.5 mm (17% of wavelength λ in water), laminated in different directions and attached to the outside of the container, were used. By using this acoustic wave diffusion layer 24, the maximum value of the acoustic wave intensity radiated from the ultrasonic transducer 20 is reduced to about 10% of 80 mW/cm ² as compared with the case where it is not attached, and the acoustic wave beam is generated. It was able to spread over a wide area. The acoustic wave reflection layer 76 is a foamed polystyrene sheet having a density of 25 kg/m ³ (about 98% is air), having a thickness of 2 mm and a 0.05 mm PET film attached to both sides, and attached to the inner wall of the water tank. Was used.

The total output of PZT transducer (7 cm ² ×800 mW/cm ² ×8 pieces=45 W) was calculated from the total weight of fish (73 g×20 fish=1.4 kg) and the amount of seawater in the aquarium (800 kg). ) Is approximately 45 W x (1.4 kg/800 kg) = 79 mW/kg. However, once the ultrasonic waves reflected on the side surface and the bottom surface are irradiated again on the fish several times, the amount is about 240 mW/kg, which is about three times as large as this. The average weight of Sakura trout after 16 weeks was 0.23 kg, and the total weight was 3.9 kg. Therefore, the average strength per body weight is estimated to be 28 mW/kg to 84 mW/kg.

The device 2 of Reference Example 1 has the same structure as the device 1, but does not use the acoustic wave diffusion layer and the acoustic wave reflection layer. The device 3 of Reference Example 2 includes only the outer case 12 having the same size and weight as the device 1, and does not use an ultrasonic transducer or an acoustic wave diffusion layer. Table 1 shows the basic specifications of these devices and the survival rate, average weight, and total weight of cherry trout after 16 weeks.

As is clear from Table 1, in Example 1 using the aquaculture device equipped with the acoustic wave diffusion layer and the acoustic wave reflection layer, the survival rate was as high as 85%, and the average weight was 0.231 kg larger. Therefore, it was shown that the total weight of 3.93 kg was 125% as compared with the total weight of 3.15 kg of Reference Example 2 in which the device of the present invention was not used. Further, compared with 3.30 kg of Reference Example 1 without the acoustic wave diffusion layer, the total weight was 119%, which was a large increase.

The device 4 of the second embodiment has a structure as shown in FIG. 5 in which four ultrasonic transducers 20 having a diameter of 3 cm are arranged in the outer case 12 which is the same container, and other conditions are the same as those of the first embodiment. Is the same as. As a low frequency sound source, 350 Hz was transmitted for 10 seconds, and 30 seconds was stopped for 60 minutes. Further, as music, a cannon of Happelbell was emitted from a speaker attached to the container for 60 minutes continuously and used.

Ultrasonic wave intensity (Isata), when just below the ultrasonic vibrator at a depth of 30cm without using the acoustic wave diffusion layer 24 is 1200 mW / cm ^2, in the case of using an acoustic wave diffusion layer 24 120 mW / cm ² met It was As the acoustic wave diffusion layer, the one having the structure shown in FIG. The first acoustic matching layer 31 is a glass plate having an acoustic impedance of 13 MRayls attached to a PZT oscillator with a thickness of λ/4, and the second acoustic matching layer 32 is an acrylic plate having an acoustic impedance of 3.3 MRayls of λ/4. I attached it in thickness. The acoustic wave diffusion layer 24 was made of epoxy resin, and the acoustic wave scattering material was a disk-shaped cavity of R30 mm having a central thickness of 2.0 mm and a diameter of 10 mm. By using this acoustic wave diffusion layer 24, the maximum value of the acoustic wave intensity radiated from the ultrasonic transducer 20 is reduced to about 10% of 120 mW/cm ² as compared with the case where it is not attached, and the acoustic wave beam is generated. It was able to spread over a wide area.

The acoustic wave reflection layer is the same as in Example 1. Based on the total weight of fish (73 g x 20 = 1.4 kg) and the amount of seawater in the aquarium (800 kg), the ratio of the actual irradiation of fish to the total output of the PZT oscillator (7 cm x 1200 mW/cm ² x 4 pieces = 34 W) The estimated value calculated from () is 34 W×(1.4 kg/800 kg)=60 mW/kg. However, once the ultrasonic waves reflected on the side surface and the bottom surface are irradiated again on the fish several times, it is estimated to be about 180 mW/kg, which is about three times as large as this. The average weight of Sakura trout in 16 weeks was 0.22 kg, and the total weight was 3.7 kg. Therefore, the average intensity per body weight is estimated to be 23 mW/kg to 66 mW/kg. The device 5 of Example 3 has the same structure as the device 4, but does not use the acoustic wave reflection layer.

The device 3 of Reference Example 2 includes only an outer case having the same size and weight as the device 1, and does not use an ultrasonic transducer or an acoustic wave reflection layer. Table 2 shows these structures and the survival rate, average weight, and total weight of cherry trout after 16 weeks.

As is clear from Table 2, in Example 2 , the survival rate was as high as 85%, and the average weight was 0.217 kg higher. For this reason, the total weight was 3.69 kg, which was 117% of the total weight of Reference Example 2 in which the apparatus of the present invention was not used. In addition, Example 3 without the acoustic wave reflection layer showed an increase of 110% as compared with 3.45 kg which is the weight of Reference Example 2 and 3.15 kg, which is an increase in the harvest amount.

The device 6 of the reference example 3 shown in Table 3 shows the result when the audible sound of 350 Hz as a sound source is transmitted to the same water tank for 10 seconds and stopped for 30 seconds for 60 minutes. The device 7 of Reference Example 4 is a case where a cannon of music Happelbell is radiated from the speaker attached to the container for 60 minutes continuously as the sound source in the same water tank. These are shown together with Reference Example 2.

The device 3 of Reference Example 2 has only the outer case having the same size and weight as the device 1, and does not use the ultrasonic transducer 20 or the acoustic wave reflection layer. Table 3 shows these structures and the survival rate, average weight and total weight of cherry trout after 16 weeks.

As is clear from Table 3, the survival rate of Reference Example 3 was as low as 65%, and the average weight was 0.243 kg. Therefore, the total weight was 3. of the total weight of Reference Example 2 in which the apparatus of the present invention was not used. A value of 3.16 kg, which is equivalent to 15 kg, was shown. Further, in Reference Example 4, the survival rate is as low as 65%, and the average weight is 0.235 kg. Therefore, the total weight is 3 compared with the total weight of 3.15 kg of Reference Example 2 in which the apparatus of the present invention is not used. The value was as low as 97% of 0.06 kg.

Next, in Example 4, the aquaculture apparatus 80 shown in FIGS. 10A and 10B is used, and the outer case 12 is made of a quadrangular pyramid ABS resin having a side wall thickness of 1.0 mm to culture aquatic products. I went. The outer case 12 is provided with an upper lid 82 and an O-ring 84 for making it a watertight structure. As the ultrasonic oscillator 20, four types of 0.5 MHz, 1.5 MHz, 3.0 MHz and 8 MHz were used. Of these, 8 MHz was an alkali niobate material which is a lead-free piezoelectric material, and the other three types were ordinary PZT oscillators. The shape of the vibrator is a disk having a diameter of 2 cm.

A glass plate having a thickness of λ/4 was attached to the ultrasonic vibrator 20 as the acoustic matching layer 22. As shown in FIG. 10, these were attached inside each of the four side surfaces of the outer case 12 of the aquaculture apparatus 80. A rechargeable lithium battery was used as the driving battery 16. A convex acoustic wave diffusion layer 24 having a diameter of 3 cm and a thickness of 4 mm, which has a plurality of cavities serving as acoustic wave diffusion portions 49, was attached to the vibrator on the side surface of the device by using ABS resin.

The pulse repetition period (PRF) was 1 msec (1000 Hz) and 1 s (1 Hz), and these were driven at a duty factor of 20%. Eight different sound sources with a total of four frequencies and two PRFs were emitted to the series for 8 seconds each.

The acoustic intensity (Isata) of this aquaculture device 80 was adjusted so that 1 kg of marine products in a 20-liter aquarium could be irradiated with an acoustic wave of 800 mW/kg. The water tank container is a rectangular container having a size of 20 liters, which is obtained by sticking a 0.05 mm PET film on the surface of styrofoam. For temperature control, circulating water whose temperature was adjusted externally was sent into the water tank with a stainless pipe to control the water temperature. As the marine products, fish trout roe collected from the same parent fish having a diameter of about 4 mm was used. The water temperature was adjusted to 4°C +-1°C. 0.5 kg of the fertilized fish roe was transferred from the water surface of the aquarium to a nylon net stretched to 10 cm. The aquaculture device 80 was floated on the water surface in the center of the aquarium, and acoustic wave stimulation was continued for 20 minutes/day, 5 times/week for 1 week. A similar device was floated on the water surface in the central part of aquarium B having the same roe for the same time without switching on and compared. For the survival rate, the fish eggs and fry that had died and discolored were taken out with tweezers every day to confirm the survival rate. The results are shown in Table 4.

As is clear from Example 4 and Reference Example 5, when the aquaculture apparatus, the aquaculture system and the aquaculture method of the present invention were used, high survival rates of fish eggs and fry could be confirmed.

From the results shown in Examples 1 to 4, the aquaculture apparatus, the aquaculture system, and the aquaculture method of the present invention have a resonance frequency of ultrasonic waves of 0.1 MHz or more and 10 MHz or less, and ultrasonic intensity (Isata) It is clear that by selecting a condition in the range of 20 mW/kg to 1000 mW/kg per unit weight and irradiating the marine products in a tank with low acoustic impedance, the survival rate can be greatly improved and the yield can be increased. Became.

10, 30, 40, 50, 52, 54, 56, 58, 60, 62, 64, 74, 80 Aquaculture device 12 Outer case 14 Substrate 15 Drive unit 16 Power supply 17 Control circuit 18 Lead wire 19 High intensity acoustic wave 20 , 41, 42 Ultrasonic transducer 21 Low-intensity acoustic wave 22, 31, 32 Acoustic matching layer 24, 36, 48 Acoustic wave diffusion layer 26 Portable equipment 28 Support stand 29 Aquaculture fish 44 Acoustic speaker 46 Outer case 49 Acoustic wave diffusion 70 Aquaculture system 72 Aquarium 76 Acoustic wave reflection layer

Claims (20)

An aquaculture device for irradiating an aquatic wave, which is at least one of a sound wave and an ultrasonic wave, to aquaculture aquaculture,
An ultrasonic transducer capable of generating the acoustic wave, a driving unit that drives the ultrasonic transducer, and an outer case that holds the ultrasonic transducer and the driving unit,
The high-intensity acoustic wave emitted from the ultrasonic transducer is diffused on the front side, and the high-intensity acoustic wave is diffused and converted into a low-intensity acoustic wave whose intensity per unit area is weaker than that of the high-intensity acoustic wave. Equipped with an acoustic wave diffusion layer made of an acoustic wave scattering material to be irradiated
The acoustic wave scattering material of the acoustic wave diffusion layer is composed of a metal mesh, and the size of the mesh is λ to λ/10 of the underwater wavelength λ of the ultrasonic wave to be used. Aquaculture equipment. The ultrasonic transducer aquaculture system according to claim 1, wherein the piezoelectric vibrator. The acoustic wave diffusion layer, the outer casing or in the interior of the outer casing outside the acoustic matching layer or the outer casing aquaculture system according to claim 1, wherein disposed on the outside of. 3. At least two acoustic matching layers for acoustic matching between the piezoelectric vibrator and fresh water or seawater as a medium are arranged, and the shape of the acoustic matching layer is larger than that of the piezoelectric vibrator. The aquaculture device described. The outer case is provided with the piezoelectric vibrator having a disk, ring or rectangular plate that generates at least two kinds of frequencies, and the fundamental wave frequency of the ultrasonic vibrator is 0.1 MHz to 10 MHz. The aquaculture device according to claim 2, wherein The aquaculture device according to claim 2, wherein the piezoelectric vibrator uses a piezoelectric material that does not use lead. The ultrasonic wave is a pulse wave, the repetition frequency thereof is 1000 Hz to 0.5 Hz, and the duty factor is 10 to 60%. At least one of these ultrasonic vibrators is arranged on the side surface of the hollow pyramid container. The aquaculture device according to claim 1. The aquaculture device according to claim 1, further comprising a removable portable electronic device or a sound generation device that generates an audible sound, a feeding sound, or a swimming sound. 9. The aquaculture apparatus according to claim 1, further comprising a rechargeable battery as a power source , the driving unit being operable by the battery, and having a waterproof function. The aquaculture device according to any one of claims 1 to 9, wherein the aquaculture device is capable of accommodating marine products and containing seawater or fresh water, and at least one of water surface and water in the aquarium. An aquaculture system, wherein the aquaculture system is provided so as to irradiate the acoustic wave into the water in the aquarium. The acoustic wave reflection layer of an acoustic wave reflection material having an acoustic wave reflectance of 90% or more for reflecting and scattering the acoustic waves is provided on at least 80% or more of the surface of the aquarium surface. The aquaculture system described. The acoustic wave reflection layer is made of a sheet, at least the front surface or the back surface thereof is covered with an organic film, the thickness is 0.05 to 1.0 mm, and the inner surface is provided with an organic material containing 90% by volume or more of gas. The aquaculture system according to claim 10 or 11. 13. The aquaculture according to claim 10, 11 or 12, wherein the organic film on the surface of the acoustic wave reflection material is fluororesin, PET, or nylon, and contains a gas layer or expanded polystyrene, expanded polyurethane, or expanded rubber inside. system. The aquaculture system according to any one of claims 10 to 13, wherein the aquaculture system is used while releasing air bubbles having a diameter of 0.01 to 10 mm into water. The aquaculture system according to any one of claims 10 to 14, further comprising a temperature control device capable of setting the temperature of seawater or fresh water in the aquarium to 2°C to 30°C. A method for aquaculture using the apparatus for aquaculture according to claim 1.
The aquaculture device, floating in the water in the aquarium containing seawater or fresh water that can contain aquatic products and freely rocks, generating the acoustic wave from the aquaculture device and reflecting it on the wall of the aquarium, Water in water A method for aquaculture, comprising applying acoustic stimulation to the product. An ultrasonic wave having an ultrasonic wave intensity (Isata) of 20 mW/kg to 1 W/kg is applied to the total weight of the marine product in water by the aquaculture device, and the aquatic product is subjected to acoustic wave stimulation for aquaculture. Item 16. A method for aquaculture of marine products according to item 16. The aquaculture device irradiates the aquatic products in the water with the acoustic waves continuously or intermittently for 10 to 60 minutes/day, 1 to 7 days/week, and 1 to 50 weeks. Aquaculture method. The aquaculture method according to any one of claims 16 to 18, wherein an aquatic speaker of the aquaculture device or a mobile phone emits acoustic waves of a frequency and intensity that activate the activity of the aquaculture. The aquaculture method according to any one of claims 16 to 19, wherein the marine products are fish, eggs of crustaceans, fry and adult fish.

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