JP2010172238A - Method for exterminating parasite and system for exterminating parasite - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for exterminating parasites, which has a small load on the environment and a high safety to the human body and a system for exterminating parasites. <P>SOLUTION: The method for exterminating parasites parasitic on cultured fishes reared in a preserve 105 includes supplying an ozone gas as microbubbles or nanobubbles to rearing water, making the cultured fishes swim in the rearing water containing the bubbles and contacting the bubbles with the gills and the body surfaces of the cultured fishes to exterminate parasites. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a parasite control method and a parasite control system that control parasites parasitized on cultured fish.

  In the aquaculture industry, regardless of whether it is freshwater or seawater, various efforts are being made to improve yields and increase productivity. In particular, suppressing the occurrence of fish diseases is one of the important initiatives. Among fish diseases, parasitic diseases are a major cause of yield reduction along with viral diseases and bacterial diseases. Parasites not only cause fish to die, but also cause secondary infection by bacteria. Therefore, development of an effective treatment for parasitic diseases is strongly desired.

  Conventionally, a medicinal bath using a pharmaceutical for marine products is known as a method for treating parasitic diseases. However, in most cases, with the exception of some fish species, the use of marine drugs for treatment is not permitted by the Pharmaceutical Affairs Law. In addition, as an accepted example, it is allowed to use marine drugs for aquaculture, such as yellowtail, but because such marine drugs are administered in large quantities in ginger and dumped directly into the sea, Gives a big load to the environment.

On the other hand, as a treatment method that does not use marine pharmaceuticals, for example, a salt water bath is known in which cultured fish is immersed in 1.0 to 1.5% salt water for a certain period of time in freshwater aquaculture. However, in the salt water bath, when the capacity of the water tank is 100 m ³ (100 t), salt of 1 t or more has to be introduced, and a great labor and cost are generated, which is a heavy burden on the aquaculture company. Furthermore, since a large amount of salt water is drained, the load on the environment is large.

Therefore, Patent Literature 1 discloses a technique for installing an aeration facility for supplying ozone gas to breeding water in a ginger and extinguishing a parasite with the ozone gas as a treatment method with a small load on the environment.
JP-A-9-94036

However, ozone gas is harmful to the human body depending on the amount of ozone gas, and the Japan Society for Occupational Health has an ozone concentration of 0.2 mg / m ³ (0.1 ppm or less), and the working environment is within 8 hours a day and 40 hours a week. There is. Therefore, if the aquaculture facility or breeding facility is in a closed environment, the ozone gas that is supplied to the breeding water will be exhausted and decomposed so that some of the ozone gas supplied from the water will not be dissipated from the surface of the water and harm the human body. It is necessary to install large-scale equipment.

  In view of the above-described problems, an object of the present invention is to provide a parasite extinguishing method and a parasite extinguishing system that have a low environmental load and high safety to the human body.

The parasite extermination method according to the present invention is a parasite extermination method for exterminating parasites parasitized in cultured fish bred in a ginger, which is obtained by supplying ozone gas to the breeding water as microbubbles or nanobubbles. It is characterized by controlling the parasites by swimming the cultured fish in the breeding water containing the bubbles, and bringing the bubbles into contact with the cage and body surface of the cultured fish.
The parasite control system according to the present invention controls the parasites parasitized on the cultured fish by swimming the cultured fish in the breeding water containing bubbles made of ozone gas and bringing the bubbles into contact with the cage and body surface of the cultured fish. A parasite control system used for a parasite control method, comprising an ozone gas generation device and a bubble supply device that supplies ozone gas generated by the ozone gas generation device to breeding water as microbubbles.

  Since the method for controlling parasites according to the present invention supplies ozone gas to the breeding water as microbubbles or nanobubbles, the bubbles can stay in the breeding water for a long time, and the bubbles can exist in the breeding water at a high density. it can. As a result, the bubbles can be efficiently brought into contact with the culm and body surface of the cultured fish, and the parasite can be effectively eliminated with a small amount of ozone gas. Further, since the bubble stays in the breeding water for a long time, the bubble can be spread over a wide area in the ginger, and the parasite can be effectively eliminated from this point.

In the present application, ginger means a place where fish and the like are kept alive, and the ginger includes a water tank.
In addition, since no marine pharmaceuticals or salt is used and the amount of ozone gas used is small, the burden on the environment is small and the safety to the human body is high. Also, since the bubble stays in the breeding water for a long time, ozone is easily decomposed and reduced to oxygen in the breeding water, and as a result, the ozone concentration in the working environment does not increase because it is difficult for the ozone to dissipate from the water surface. From this point of view, it is highly safe for the human body.

  The reason why the bubbles can stay in the breeding water for a long time when the ozone gas is changed to microbubbles or nanobubbles will be described in detail. For example, a bubble with a diameter of 3 mm has a rising speed. Is about 0.3 m / s, while the microbubble with a diameter of 100 μm has an ascending speed of about 0.005 m / s. If the bubble diameter is changed from millimeter to micro order, the bubble stays in the breeding water. The time to do is dramatically increased. In the present application, microbubble means a bubble having an average diameter (diameter) of micro order, nanobubble means a bubble having an average diameter (diameter) of nano order, and millibubble means an average diameter (diameter) of millimeter. Means an order bubble.

  The reason why the bubbles can be present at high density in the breeding water when the ozone gas is changed to microbubbles or nanobubbles will be described in detail. Microbubbles are likely to exist at a high density in the breeding water because the bubbles are difficult to combine. The number of bubbles per unit volume of water varies depending on the size of the bubbles. When the bubble diameter is 20 μm, there can be approximately 600,000 bubbles in 1 ml of water. can do.

In addition, if the bubble stays in the breeding water for a long time, the reason why the bubble can spread over a wide area in the ginger is explained. This is because the bubbles spread over a wide area on the flow.
In the method for controlling parasites according to the present invention, when the bubbles have an average diameter of 50 μm or less, different properties appear from those of ordinary bubbles. Specifically, the buoyancy is significantly reduced, and the rising speed is also significantly increased. Since it becomes small and the surface area with respect to a volume also becomes notably large, the parasite extermination effect mentioned above and the effect of the safety improvement with respect to a human body become more remarkable.

Moreover, when the amount of ozone supply per hour for 1 m ³ of breeding water by bubbles is 22.5 to 45.6 mg / m ³ · hr, if a bubble made of ozone gas is supplied for 6 hours, it is a cage or body of cultured fish More than 97% of parasites parasitized on the table could be removed and removed.
Further, when the parasite is an extracorporeal parasite, the probability of the parasite coming into contact with the bubble made of ozone gas is high, and thus the extermination / peeling effect is remarkable. In particular, it has a high extermination / exfoliation effect against ectoparasites classified as flat animal monopods. Extracorporeal parasites include Gyrodactylus, Dactyrogillus, Trichodina, Gurgae, Chilodonella, Epistilis, Ichthiobod, Glochidium, Sputum Myxophyceae, Pseudodactyrogillus, Tetraonkus, Caligus, Lepeoftails, Salmincholas, Algulne Ergacils, Ikutiofiriusu (freshwater white spotted caterpillar), cryptocarion (sea white spotted caterpillar), Lernea (squid), Benedenia (Hadamushi), Neo Benedenia (Hadamushi), Heteraxine, Lexanella (Tainoe), Vivagina (Eramushi), Lamelogiscus, anoprodyscus, scotch ciliate, amylusinium, heterobotulium, pseudocaligus, codonophyllus (shimazinoe), micro-cochile, didymocystis, etc. It is.

  Since the parasite control system according to the present invention includes a bubble supply device that supplies ozone gas to the breeding water as microbubbles, it is difficult to give a large load to the environment when the parasite is controlled, and the safety to the human body is high.

Hereinafter, a parasite control method and a parasite control system according to the present embodiment will be described with reference to the drawings.
[Parasite control system]
FIG. 1 is a schematic configuration diagram showing a ginger in which a parasite control system according to the present embodiment is installed. FIG. 1 (a) is a plan view and FIG. 1 (b) is a longitudinal sectional view. As shown in FIG. 1, the parasite control system according to the present embodiment includes an oxygen supply unit 101, an ozone gas generation device 102, and a bubble supply device 103.

  The oxygen supply means 101 is a known oxygen gas generator (for example, a PSA oxygen gas generator). The oxygen supply means 101 is not limited to an oxygen gas generator, and may be, for example, an oxygen cylinder or a well-known dry air supply device. When the ozone gas generator 102 wants to generate high-concentration ozone gas, an oxygen gas generator or oxygen cylinder is used, and when low-concentration ozone gas is acceptable, an air supply device is used. It is possible.

  The ozone gas generation device 102 is also a well-known ozone gas generation device, which is a high voltage that applies a high voltage between a flow path through which oxygen passes, two electrode plates disposed in the flow path, and two electrode plates. A controller (both not shown) for controlling the generation circuit and the high voltage generation circuit is provided. When a voltage is applied between the two electrode plates, oxygen supplied from the oxygen supply means 101 via the air supply hose 104 is supplied. Part of it is converted to ozone, generating ozone gas consisting of oxygen and ozone. The amount of ozone conversion can be adjusted by controlling the time for applying the voltage to the electrode plate with the controller, and the ozone concentration of ozone gas depends on the amount of ozone conversion. Therefore, the ozone conversion amount can be adjusted by adjusting the ozone conversion amount. The density is adjusted. In addition, the structure which controls the height of the voltage applied to an electrode plate with a controller and adjusts the ozone conversion amount may be sufficient.

In addition, the ozone gas generator is not limited to a type that generates ozone by flowing oxygen to a generator that has been subjected to a high voltage as described above, and is a type that converts oxygen into ozone by irradiating ultraviolet rays of a specific wavelength. Or a type that generates ozone by electrolyzing water.
The bubble supply device 103 drives the microbubble generator 1 as shown in FIG. 2 disclosed in Japanese Patent Laid-Open No. 2008-23435, a pump unit for sucking the breeding water from the ginger 105, and the pump unit Motor unit, an adjustment valve for adjusting the supply amount of ozone gas supplied from the ozone gas generator 102, a controller (both not shown) for controlling the adjustment valve, and when the motor unit is turned on, When the pump unit rotates and the breeding water in the ginger 105 is supplied to the microbubble generator 1 through the flow path (for example, a pipe, a hose, etc.) 106, while the regulating valve is opened, the ozone gas generator 102 Ozone gas is supplied to the microbubble generator 1 through the air supply hose 107.

The bubble supply device is not limited to the one disclosed in Japanese Patent Application Laid-Open No. 2008-23435, and any device that can generate microbubbles or nanobubbles made of ozone gas may be used.
FIG. 2 is a partially broken plan view showing the microbubble generator. As shown in FIG. 2, the microbubble generator 1 includes a casing 2 having a flow path 23 through which breeding water can pass from one end 21 to the other end 22, and the breeding water passing through the flow path 23 at the other end 22 of the casing 2. Accelerating means 3 for accelerating toward

  The direction of the arrow with “OUT” in FIG. 2 corresponds to the axial flow direction in which the liquid fluid passes through the casing 2. The casing 2 is formed by connecting an introduction block 24, an acceleration block 25, and a discharge block 26 in this order. The flow path 23 has a cone-shaped part 5, a throat part 6, and a divergent nozzle part 7, and is formed consistently inside the introduction block 24, the acceleration block 25, and the discharge block 26.

In the introduction block 24, an introduction port 28 is opened at the back of a hose union 27 provided on the side thereof, and breeding water supplied from the pump unit and ozone gas supplied from the ozone gas generator 102 are introduced. When supplied to the mouth 28, breeding water and ozone gas are introduced into the flow path 23 from the direction of the arrow marked “IN” in FIG. 2.
The cone-shaped portion 5 has a shape that decreases in diameter as it goes from one end 21 to the other end 22 of the casing 2, and a portion where the diameter is minimized is the throat portion 6. In addition, a valve body 9 fixed to the front portion of the advance / retreat rod 8 is inserted into the throat portion 6. The advance / retreat rod 8 is a rod that extends in the axial direction, and is screwed into the introduction block 24.

The valve body 9, the cone-shaped portion 5, and the advance / retreat rod 8 are elements constituting the acceleration means 3 of the microbubble generator 1. By operating the handwheel handle 82 attached to the rear part of the advance / retreat rod 8 and rotating the advance / retreat rod 8 relative to the casing 2, the valve element 9 can be freely displaced in the axial direction.
The breeding water and ozone gas introduced from the introduction port 28 are mixed in the flow path 23, thereby generating breeding water containing microbubbles made of ozone gas, and this breeding water flows into the flow path (for example, pipe, hose, etc.). It is discharged into the ginger 105 through 108. In this way, breeding water containing microbubbles made of ozone gas is supplied into the ginger 105. In addition, groundwater was supplied into the ginger 105 through the groundwater supply path 110. In addition, a submersible pump 109 for stirring is installed in the ginger 105, and the breeding water in the ginger 105 flows in the direction of the arrow indicated by reference numeral 111 by the submersible pump 109 for stirring. Go across the entire ginger 105.

  The diameter of the microbubble depends on the amount of breeding water and ozone gas supplied to the microbubble generator 1. The supply amount of breeding water can be adjusted by attaching an inverter device to the motor unit, and the supply amount of ozone gas can be adjusted by controlling an adjustment valve. In the present embodiment, the supply amount of the breeding water is kept constant without being controlled, and the diameter of the microbubble is determined by controlling the adjustment valve with the controller. Note that the diameter of the microbubbles can be adjusted by displacing the valve body 9 of the microbubble generator 1 manually or under the control of a controller.

The amount of ozone supplied per hour with respect to 1 m ³ of breeding water using microbubbles made of ozone gas depends on the ozone concentration and gas flow rate of ozone gas supplied from the ozone gas generator 102 to the bubble supply device 103. The ozone concentration of the ozone gas can be adjusted by adjusting the amount of ozone conversion in the ozone gas generator 102 as described above. Further, the gas flow rate can be adjusted by controlling the regulating valve of the valve supply device 103.

[Method of controlling parasites]
The parasite control method according to the present embodiment is implemented using the parasite control system according to the present invention.
<Example 1>
FIG. 3 is a diagram for explaining a parasite control test according to Example 1. FIG. As shown in FIG. 3, in the parasite control test according to Example 1, Lake Ayu from Lake Biwa (average fish weight 1.6 g) infested with guillodactylus was used as the test fish 201. Four water tanks with a capacity of 50 L were divided into two test zones, non-treatment zones 202 and 203 and microbubble treatment zones 204 and 205, and 100 test fishes 201 were accommodated in each of them.

In the untreated sections 202 and 203, the test fish 201 was bred by flowing through groundwater through a path passing through the flow path 206 and the flow path 207.
In the microbubble treatment sections 204 and 205, microbubbles made of ozone gas were supplied by the parasite extermination system through a path through the flow path 208 and the flow path 207 in addition to the groundwater pouring. Specifically, ozone gas is generated by the ozone gas generator 210 using oxygen generated by the oxygen supply means 209, and the ozone gas is generated as microbubbles by the bubble supply device 211. The breeding water (total capacity 100L = 50L capacity water tank 2 units).

The ozone gas supplied from the ozone gas generator 210 to the bubble supply device 211 was adjusted to have an ozone concentration of 3.8 g / m ³ and a gas flow rate of 20 mL / min (0.0012 m ³ / hr). In order to reproduce this condition with 1 m ³ of breeding water, the amount of ozone supplied per hour with respect to 1 m ³ of breeding water is 45.6 mg / m ³ · hr (Formula 1).
^{{3.8g / m 3} × {} 0.0012m 3 /hr}×{1/100L}={45.6μg/L · hr} = {45.6mg / m 3 · hr} ··· ( wherein 1 )
The microbubbles supplied from the bubble supply device 211 to the breeding water were adjusted so that the average diameter was 50 μm. In addition, the diameter of the bubble traps a part of the breeding water containing the microbubbles discharged from the bubble supply device 211 as close as possible to the microbubble generation part (that is, the upstream side in the flow path 208), The trapped breeding water was introduced into a glass tube for bubble observation, and the bubble stuck to the tube wall was photographed with a microscope while the breeding water was flowing in the glass tube, and the measurement was performed by analyzing the image. The diameter of the bubble may be measured using a particle size molecular meter, or may be measured using an optical measuring instrument such as a laser measuring instrument.

As a result of investigating the toxicity of ozone gas to the test fish, it was determined that the time for supplying ozone gas was preferably within 6 hours. Therefore, the supply of ozone microbubbles was stopped for 6 consecutive hours, and then the animals were reared only by pouring groundwater. .
There are various types of parasites to be controlled, but the target was Girodactylus, which caused severe damage in ayu farming as test fish 201. Immediately before the supply of microbubbles and 6 hours after the start of supply, 10 fishes were picked up, and the left chest fin, dorsal fin, and girodactylus parasitizing left body side mucus were counted by microscopic observation. The observed giroductactylus was counted by distinguishing between individuals that were actively exercising and those that were not. Sampling was performed 24 hours later, 72 hours later, and 168 hours later in order to grasp the change in the number of worms of Girodactylus after the supply of microbubbles was stopped.

FIG. 4 is a diagram showing the effect of controlling parasites according to Example 1, FIG. 4 (a) shows the results when ozone gas was supplied as microbubbles, and FIG. 4 (b) did not supply ozone gas. The result of the case is shown. In FIG. 4, “exercise” indicates the result of sampling an active parasite individual, and “non-exercise” indicates the result of sampling an individual that is not.
As shown in FIGS. 4 (a) and (b), the total number of worms of 10 Ayu guildactyls immediately before feeding was 259. Six hours later, the number of worms decreased to 176 (68.0%) in the untreated sections 202 and 203, and the number of worms decreased to 7 (2.7%) in the microbubble treated sections 204 and 205. . From this result, it was confirmed that the microbubbles made of ozone gas had an extermination effect against gyrodactylus parasitized on the body surface of the test fish. After 24 hours, the number of worms was 18, and after 72 hours, the number of worms was 21, and after 168 hours, the number of worms was almost flat at 23.

<Comparative example>
Next, in order to confirm whether microbubbles are an effective means for controlling parasites, ozone gas is supplied to the breeding water using airstone as millibubbles with a diameter of 1 mm or more. Compared.
FIG. 5 is a diagram for explaining a parasite control test according to a comparative example. As shown in FIG. 5, Ayu from Lake Biwa (average fish body weight: 3.2 g) in which girodactylus parasitizes was used as a test fish 301. Two test tanks with a capacity of 50 L were set as two test sections, that is, an untreated section 302 and a millibubble treated section 303, and 150 test fishes 301 were accommodated in each of them.

  In the non-treatment section 302, the water is bred by flowing groundwater through a path passing through the flow path 304 and the flow path 305, and in the millibubble processing section 303, oxygen supply means is supplied by a path flowing from the flow path 306 to the flow path 305 in addition to flowing groundwater. Ozone gas was generated by the ozone gas generator 308 using the oxygen generated in 307, and the ozone gas was supplied to the breeding water as millibubbles by the airstone 309. The ozone gas was adjusted to have the same ozone concentration and gas flow rate as in Example 1. As the oxygen supply means 307 and the ozone gas generator 308, those having the same ability as in Example 1 were used.

Immediately before the supply of millibubbles, 1 hour, 3 hours, 6 hours and 24 hours after the start of supply, 10 sweetfish were picked up, and the left pectoral fin, dorsal fin, and left-side mucus were counted by microscopic observation. . The observed giroductactylus was counted by distinguishing between individuals that were actively exercising and those that were not.
6A and 6B are diagrams showing the effect of controlling the parasite according to the comparative example. FIG. 6A shows the result when ozone gas is supplied as millibubbles, and FIG. 6B shows the case where ozone gas is not supplied. Results are shown. The meanings of “exercise” and “non-exercise” in FIG. 6 are the same as those in FIG.

  As shown in FIGS. 6 (a) and 6 (b), the total number of worms of 10 guillodactylus immediately before feeding was 94. One hour later, the number of worms was 198 in the untreated group 302, and the number of worms was 76 in the millibubble treated group 303. Three hours later, the number of worms in the untreated section 302 was 86, and the number of worms was 59 in the millibubble treated section 303, and after six hours, the number of worms was 105 in the untreated section 302 and the number of worms in the millibubble treated section 303. The number of bodies became 97, and further 24 hours later, the number of worms in the untreated group 302 was 166, and the number of worms in the millibubble treated group 303 was 162.

  The large variation in the total number of parasites is considered to be due to individual variations in the number of parasites that are parasitic on the surface of the test fish. In contrast to Example 1, since the number of parasites did not decrease with millibubbles, it was confirmed that even if ozone gas was bubbled to a millimeter size, it was difficult to obtain a parasite control effect. From this, it was found that even if ozone gas was supplied to the breeding water with an air diffuser or a diffuser, it was difficult to obtain the effect of parasite control.

<Example 2>
7A and 7B are diagrams for explaining a parasite control test according to Example 2, FIG. 7A is a plan view of a ginger in which a parasite control system is installed, and FIG. 7B is a longitudinal sectional view thereof. It is. As shown in FIG. 7, in Example 2, the parasite extermination test was conducted with a water volume of 8 m ³ (8 t) which is a practical water tank capacity. A bubble supply device 401 having a capacity four times that of the bubble supply device 211 according to the first embodiment was used. As the oxygen supply means 402 and the ozone gas generator 403, those having the same ability as in Example 1 were used. As in Example 1, ozone gas was generated by the ozone gas generator 403 using oxygen generated by the oxygen supply means 402, and microbubbles made of ozone gas were supplied to the breeding water in the water tank 404 by the bubble supply device 401.

  The breeding water was taken in through the flow path 405, microbubbles made of ozone gas were supplied to the breeding water by the bubble supply device 401, and the fed breeding water was discharged into the water tank 404 through the flow path 406. In addition, a plurality of discharge ports 407 were provided so that the microbubbles spread throughout the water tank 404. Further, an agitation submersible pump 408 was installed in the water tank 404 and flowed so that the entire breeding water turned in the direction of the arrow indicated by reference numeral 409. For the health of the test fish 410, well water was supplied from the groundwater supply channel 411 so that the water in the tank was replaced three times a day.

The ozone gas supplied from the ozone gas generator 403 to the bubble supply device 401 was adjusted so that the ozone concentration was 3.0 g / m ³ and the gas flow rate was 1 L / min (0.06 m ³ / hr). Under this condition, the amount of ozone supplied per hour for 1 m ³ of breeding water is 22.5 mg / m ³ · hr (Formula 2).
^{{3.0g / m 3} × {} 0.06m 3 / hr} × {1 / 8m 3} = 22.5mg / m 3 · hr ··· ( Equation 2)
Ayu from Lake Biwa (average fish weight: 3.8 g) infested with guillodactylus was designated as test fish 410. In order to easily collect the test fish 410, 50 test fishes were accommodated in a cage 412 having a height of 30 cm, a width of 60 cm, and a depth of 45 cm and installed in the aquarium 404. Immediately before the supply of microbubbles and 3 hours, 6 hours and 9 hours after the start of supply, 10 sweetfish were taken up, and girodactylus parasitizing the left chest fin, dorsal fin and left body side mucus was counted by microscopic observation.

  FIG. 8 is a diagram illustrating a parasite control effect according to the second embodiment. As shown in FIG. 8, the total number of worms of 10 Ayu guildactyls immediately before feeding was 346. After 3 hours, the total number of worms was 42. After 6 hours, the total number of worms was 7. After 9 hours, the total number of worms was 3. . In addition, since the death of sweetfish was not confirmed even 6 hours after the start of microbubble supply, it is considered that the safety to the test fish 410 is high under these conditions.

<Summary>
From Examples 1 and 2 and the comparative example, the parasite extermination effect obtained by making ozone gas into microbubbles can be obtained very easily by the ozone gas generator installed beside the ginger and the bubble supply device that generates microbubbles. be able to. Since the amount of ozone gas used is extremely small, there is almost no ozone gas dissipated from the surface of the water, and the safety to the human body can be secured even in an indoor closed environment, so the places where ozone gas can be used greatly expand.

For example, in practical terms, if the aquarium has a capacity of 100 m ³ (100 t), even in high-density breeding with a fish weight of 3 to 10 kg per ton of water, the amount of ozone gas used is approximately 12 under the same conditions as in Example 2. .5L / min is extremely small, and the ozone gas generator is small, so the introduction cost and the subsequent maintenance cost are low.
Japanese Patent Laid-Open No. 9-94036 discloses a method for controlling parasites using ozone gas. However, the method for controlling parasites according to the present invention is not limited to hatching larvae of parasites, but also controls and peels adult bodies. In addition, in the millibubble obtained by the diffuser or the diffuser described in the publication, the residence time in water is short and its influence range is narrow, so it is necessary to arrange the ozone gas diffuser so as to surround the ginger. The large amount of millibubbles discharged from the air diffusers arranged in all directions in this way stirs the water vigorously due to the airlift effect, so it is not difficult to imagine the stress given to the cultured fish. There is a possibility of raising the mud, which may worsen the breeding environment. Furthermore, such a method using millibubbles requires an ozone gas exhaust facility and a decomposition / removal facility when used in a closed indoor environment.

  On the other hand, in the method for controlling parasites according to the present invention, by making ozone gas into microbubbles, the staying time of the bubbles in the breeding water is dramatically increased, and the microbubbles are gently spread over a wide range in the breeding water. Go. In the case of microbubbles, the breeding water is not vigorously stirred by the airlift effect, so that stress is not given to the cultured fish. Furthermore, microbubbles are present in large amounts in the breeding water, and the probability of contact with cultured fish is extremely high. In addition, since the microbubbles have a strong adsorptive property to the object, they are frequently adsorbed on the body surface of the cultured fish and parasites, and are frequently removed and detached from the body surface of the cultured fish. In terms of safety, ozone is sufficiently consumed in the breeding water, and its usage is extremely small. Therefore, there is almost no dissipation of ozone gas from the water surface, and there is little possibility of harm to the human body.

Incidentally, hazards with respect to fish ozone have also been reported, the ozone concentration in the rearing water in aquaculture is preferred that 0.5 g / m ³ or less, even 0.322 g / m ³ For example, if the fresh water trout It has been reported that it will die within 5 hours ("Ozone Basics and Applications" Hidetoshi Sugimitsu 1995 Korin). Therefore, if the range of the ozone supply conditions per 1 m ³ (1 t) of the breeding water of Examples 1 and 2 is 22.5 to 45.6 mg / m ³ · hr, sufficient parasite extermination and release effects are obtained. In addition, even if ozone gas is dissolved in 100% water, the ozone concentration per 1 m ³ (1 t) of the breeding water is sufficiently low so that there is almost no influence on the cultured fish.

If the average diameter of the microbubbles becomes too large, the surface area per volume becomes too small and the contact area with the body surface of the cultured fish decreases. On the other hand, if the average diameter becomes too small, the surface tension becomes too large and bubbles are difficult to adhere to the surface of the cultured fish. Microbubbles having an average diameter of 10 to 100 μm have a large contact area and easily adhere to the body surface.
The parasite control system according to the present invention is easy to handle because the device configuration is simple. For example, when ozone gas is used, toxicity to farmed fish must be taken into account, but it is possible to provide a function for easily setting the time and concentration for supplying microbubbles. Further, even if there is any influence on the cultured fish, it is only necessary to stop the device, so that it is easy to deal with an emergency.

As described above, the effect obtained by making the ozone gas into microbubbles can easily obtain the effect of removing and removing the parasite, and can be easily and carefully considered for the safety during use. Therefore, it can be said that it is an ideal parasite control method and parasite control system.
[Modification]
The parasite extermination method and the parasite extermination system according to the present embodiment have been specifically described above based on the embodiment, but the parasite extermination method and the parasite extermination system according to the present invention are the above-described implementations. It is not limited to the form.

For example, a configuration may be adopted in which a buffer tank is interposed on the breeding water transfer path from the bubble supply device to the ginger and bubbles having a relatively large diameter are removed from the breeding water by the buffer tank.
FIG. 9 is a schematic configuration diagram illustrating a water tank in which the parasitic insect control system according to the first modification is installed. FIG. 10 is a schematic configuration diagram illustrating a water tank in which the parasitic insect control system according to the second modification is installed. The parasite control system according to the first and second modifications has basically the same configuration as the parasitic control system according to the second embodiment except for the configuration related to the buffer tank. Therefore, the configuration related to the buffer tank will be mainly described, and description regarding other portions will be omitted or simplified.

  As shown in FIG. 9, the parasite control system according to the first modification includes ozone gas generated in the bubble supply device 501 by generating ozone gas in the ozone gas generation device 503 using oxygen generated in the oxygen supply means 502. Microbubbles are supplied to the breeding water in the water tank 504. The configurations of the bubble supply device 501, the oxygen supply means 502, the ozone gas generation device 503, and the water tank 504 are substantially the same as the configurations of the bubble supply device 401, the oxygen supply means 402, the ozone gas generation device 403, and the water tank 404 of the second embodiment. .

  A buffer tank 505 is interposed on the breeding water transfer path from the bubble supply device 501 to the water tank 504, and ground water serving as breeding water is supplied into the buffer tank 505 from the ground water supply path 506. The bubble supply device 501 receives feed water from the buffer tank 505 via the flow path 507, and includes the microbubbles in the breeding water. The breeding water including the microvalve is returned from the bubble supply device 501 to the buffer tank 505 through the flow path 508. As a result, breeding water containing microbubbles is stored in the buffer tank 505.

  In a state where the breeding water is stored in the buffer tank 505, bubbles having a relatively large diameter contained in the breeding water float on the water surface and are dissipated to the air layer in the buffer tank 505. This removes bubbles of relatively large diameter from the breeding water. Ozone gas derived from bubbles having a relatively large diameter removed from the breeding water is transferred from the buffer tank 505 to the waste ozone decomposer 509, decomposed into oxygen gas by the waste ozone decomposer 509, and released into the atmosphere. . In this way, the ozone gas derived from the relatively large diameter bubble that is easily dissipated from the breeding water is recovered in the buffer tank 505, decomposed into oxygen gas by the waste ozone decomposer 509, and then released into the atmosphere. It is difficult for bubbles having a relatively large diameter to be mixed into the water tank 504, and the amount of ozone gas dissipated from the water surface of the water tank 504 can be reduced. Therefore, parasite control with higher safety to the human body can be realized.

  In the buffer tank 505, the relatively small diameter bubble contained in the breeding water hardly floats on the water surface, so that it remains in the breeding water and is supplied to the water tank 504 through the channel 510. Thus, in the parasite control system according to the first modification, the breeding water containing the microbubbles generated by the bubble supply device 501 is temporarily retained in the buffer tank 505 and then supplied to the water tank 504. It is possible to remove bubbles of relatively large diameter from the water. It should be noted that the diameter of the bubble to be removed can be appropriately adjusted by adjusting the time for retaining the breeding water in the buffer tank 505. For example, there is a case where a millivalve is mixed in breeding water containing microbubbles generated by the bubble supply device 501, but if such a millibubble is to be removed, the millibubble floats on the water surface. It is only necessary to keep the breeding water in the buffer tank 505 for a necessary time.

  In the above example, the breeding water in the buffer tank 505 is supplied to the bubble supply device 501. However, the breeding water in the water tank 504 is supplied via a flow path 511 as indicated by a virtual line (two-dot chain line). It may be configured to supply to the bubble supply device 501. Moreover, when it is set as the structure which supplies the breeding water in the water tank 504 to the bubble supply apparatus 501 in this way, like the parasite extermination system which concerns on the modification 2 shown in FIG. The configuration may be such that the water tank 504 is supplied instead of the buffer tank 505.

  INDUSTRIAL APPLICABILITY The present invention can be used for the cultivation of freshwater fish and saltwater fish performed at the sea surface, lake surface, land culture facility or breeding facility.

It is a schematic block diagram which shows the ginger which installed the parasite extermination system which concerns on this Embodiment, FIG. 1 (a) is a top view, FIG.1 (b) is a longitudinal cross-sectional view. It is a partially broken top view which shows a microbubble generator. It is a figure for demonstrating the parasite extermination test which concerns on Example 1. FIG. It is a figure which shows the parasite control effect which concerns on Example 1, FIG. 4 (a) shows the result at the time of supplying ozone gas as a microbubble, FIG.4 (b) shows the result at the time of not supplying ozone gas. Show. It is a figure for demonstrating the parasite extermination test which concerns on a comparative example. It is a figure which shows the parasite control effect which concerns on a comparative example, Fig.6 (a) shows the result at the time of supplying ozone gas as a millibubble, FIG.6 (b) shows the result at the time of not supplying ozone gas. It is a figure for demonstrating the parasite extermination test which concerns on Example 2, Fig.7 (a) is a top view of the ginger which installed the parasite extermination system, FIG.7 (b) is the longitudinal cross-sectional view. It is a figure which shows the parasite extermination effect which concerns on Example 2. FIG. It is a schematic block diagram which shows the water tank which installed the parasite extermination system which concerns on the modification 1. FIG. It is a schematic block diagram which shows the water tank which installed the parasite extermination system which concerns on the modification 2.

102 Ozone gas generator 103 Bubble supply device 105 Ginger

Claims (5)

A parasite control method for controlling parasites parasitized in cultured fish bred in ginger,
Supplying ozone gas to the breeding water as microbubbles or nanobubbles, swimming the cultured fish in the breeding water containing the bubbles obtained thereby, and controlling the parasites by bringing the bubbles into contact with the cage and body surface of the cultured fish Parasite control method characterized by.   The parasite control method according to claim 1, wherein the bubble has an average diameter of 50 μm or less. The method for controlling parasites according to claim 1 or 2, wherein an ozone supply amount per hour for 1m ³ of breeding water by the bubble is 22.5 to 45.6 mg / m ³ · hr.   The method of claim 1, wherein the parasite is an extracorporeal parasite. Parasite control used in parasite control methods to control parasites parasitized on cultured fish by swimming the cultured fish in the breeding water containing bubbles made of ozone gas and bringing the bubbles into contact with the cage and body surface of the cultured fish A system,
A parasite control system comprising: an ozone gas generator; and a bubble supply device that supplies the ozone gas generated by the ozone gas generator as breeding water to the breeding water.

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