Carbon dioxide supply method and carbon dioxide supply apparatus

Abstract

This provides a simpler technique for inducing avoidance behavior in aquatic organisms. [Solution] The carbon dioxide supply method includes a supply step of supplying at least one of a carbon dioxide-containing gas and carbon dioxide-containing water containing carbon dioxide in a predetermined proportion to a predetermined body of water such that the concentration of dissolved carbon dioxide in the body of water exceeds 100 mg / L.

Description

Technical Field

[0001] The present invention relates to a carbon dioxide supply method and a carbon dioxide supply device for causing avoidance behavior in aquatic organisms.

Background Art

[0002] Damage caused by aquatic organisms such as algae grazing has become a problem. Patent Document 1 describes a technique for applying a stimulating sound so that avoidance behavior occurs in fish that cause grazing damage to algae and the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of a stimulating sound for causing avoidance behavior in fish, it is necessary to set a frequency pattern combining a plurality of frequencies. In addition, the frequency pattern for causing avoidance behavior varies depending on the fish species. Therefore, in the technique described in Patent Document 1, the operation of setting the frequency pattern for causing avoidance behavior can be complicated.

[0005] One aspect of the present invention has been made in view of the above-described problems, and an object thereof is to provide a simpler technique for causing avoidance behavior in aquatic organisms.

Means for Solving the Problems

[0006] In order to solve the above problems, a carbon dioxide supply method according to one aspect of the present invention includes a supply step of supplying at least one of a carbon dioxide-containing gas and carbon dioxide-containing water containing carbon dioxide at a predetermined ratio to a predetermined water area so that the concentration of dissolved carbon dioxide in the water area exceeds 100 mg / L.

[0007] To solve the above problems, a carbon dioxide supply device according to one aspect of the present invention comprises a measuring unit for measuring the concentration of dissolved carbon dioxide in a predetermined body of water, and a supply unit that, referring to the measurement results from the measuring unit, supplies at least one of a carbon dioxide-containing gas and carbon dioxide-containing water containing carbon dioxide in a predetermined proportion to the predetermined body of water so that the concentration of dissolved carbon dioxide in the body of water exceeds 100 mg / L. [Effects of the Invention]

[0008] According to one aspect of the present invention, a simpler technique can be provided for inducing repellent behavior in aquatic organisms. [Brief explanation of the drawing]

[0009] [Figure 1] This is a flowchart showing the flow of a carbon dioxide supply method according to an embodiment of the present invention. [Figure 2] This is a schematic diagram showing an example of the configuration of a carbon dioxide supply device according to an embodiment of the present invention. [Figure 3] This is a schematic diagram showing an example of the configuration of a carbon dioxide supply device according to an embodiment of the present invention. [Figure 4] This is a schematic diagram showing an example of the configuration of a carbon dioxide supply device according to an embodiment of the present invention. [Figure 5] This is a schematic diagram showing an example of the configuration of a carbon dioxide supply device according to an embodiment of the present invention. [Figure 6] This is a schematic diagram showing the configuration of a carbon dioxide supply device according to an embodiment of the present invention. [Figure 7] This figure shows the change in the concentration of dissolved carbon dioxide over time according to an embodiment of the present invention. [Figure 8] This image shows the changes over time in a test fish according to an embodiment of the present invention. [Figure 9] This figure shows the changes over time in the localization area and health status of test fish according to embodiments of the present invention. [Modes for carrying out the invention]

[0010] [Embodiment 1] Hereinafter, an embodiment of the present invention will be described.

[0011] (Outline of carbon dioxide supply method M10) In the distribution area of seaweeds and seaweed aquaculture, etc., damage caused by herbivorous fish that eat algae has become a problem. As a countermeasure, in addition to the above-mentioned stimulating sounds, for example, the installation of nets is effective, but as the scale of aquaculture increases, the burden of installing and maintaining the nets (including measures against attached organisms) becomes larger. In addition, due to damage caused by herbivorous fish and omnivorous echinoderms, algal beds in coastal areas are damaged, and the amount of carbon dioxide fixation as blue carbon may decrease.

[0012] The carbon dioxide supply method M10 is a method for causing avoidance behavior in aquatic organisms such as fish and echinoderms by increasing the concentration of dissolved carbon dioxide in a predetermined water area.

[0013] For example, in the case of fish, when in contact with high-concentration carbon dioxide, it shows the following reactions as avoidance behavior.

[0014] (1) Thrashing violently while showing a nose-raising-like behavior.

[0015] (2) The reaction to stimulation is significantly weak, but the body balance is maintained. The respiratory movement is deep and fast.

[0016] (3) Losing body balance and rolling over, almost stationary.

[0017] At the stage of (1) above, the fish moves away from near the seaweed to a distance. In the states of (2) and (3) above, it is carried by the current and moves away from near the seaweed by sinking downward, etc. Note that (2) and (3) are anesthetic effects, and the fish will recover when the surrounding carbon dioxide concentration decreases, so the impact on the fish and the organisms living in the surrounding area is small.

[0018] (Flow of carbon dioxide supply method M10) The flow of the carbon dioxide supply method M10 according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a flowchart showing the flow of the carbon dioxide supply method M10. The carbon dioxide supply method M10 includes a supply step S11 as shown in FIG. 1.

[0019] (Supply step S11) The supply step S11 is a step of supplying at least one of a carbon dioxide-containing gas and carbon dioxide-containing water containing carbon dioxide at a predetermined ratio to a predetermined water area so that the concentration of dissolved carbon dioxide in the water area exceeds 100 mg / L. The supply step S11 is executed by the supply unit 12 provided in the carbon dioxide supply device 1 described later.

[0020] The predetermined water area is a water area set so that a repellent action occurs in a predetermined aquatic organism. The predetermined water area may be, for example, a water area where algae such as seaweed grow. That is, the predetermined water area may be, for example, a water area containing salt such as a seawater area. For example, the predetermined water area may be a shallows or the like, or may be a water area with a greater water depth. Specific examples of the predetermined water area include a farm for cultivating algae such as seaweed. Specific examples of seaweed growing in the predetermined water area include Sargassum genus such as Akamoku that grows upward, Kombu, Arame, Kazime, Krome, Wakame, etc. that grow below during rope cultivation, and Zostera marina and Corethrodendron frutescens that grow in the sandy mud area on the seabed.

[0021] The predetermined aquatic organism is an aquatic organism that discharges carbon dioxide with respiration and is an aquatic organism that can cause a harmful event in a predetermined water area. An example of such a harmful event is predation on beneficial algae. An example of the predetermined aquatic organism is a fish (algivorous fish) that feeds on beneficial seaweed growing in a predetermined water area. Specific examples of such fish (algivorous fish) include Aigo, Budai, Isuzumi, Haze, etc. In addition, omnivorous echinoderms typified by sea urchins are also cited as an example of aquatic organisms that cause damage to seaweed.

[0022] The dissolved carbon dioxide concentration in a designated body of water should be such that designated aquatic organisms exhibit avoidance behavior. Specifically, the dissolved carbon dioxide concentration in the designated body of water should be greater than 100 mg / L. More preferably, the dissolved carbon dioxide concentration in the designated body of water should be greater than 200 mg / L.

[0023] Carbon dioxide-containing gas is a gas that contains carbon dioxide in a predetermined proportion. The concentration of carbon dioxide in the carbon dioxide-containing gas exceeds the concentration of carbon dioxide in the atmosphere, which is 400 ppm. The carbon dioxide-containing gas may also contain high-purity carbon dioxide. Specific examples of sources for carbon dioxide-containing gas include carbon dioxide gas cylinders, dry ice, and exhaust gas produced by chemical reactions such as combustion of carbon-containing substances. Exhaust gas that can serve as a source for carbon dioxide-containing gas may, for example, be exhaust gas produced by the operation of a plant. The concentration of carbon dioxide in exhaust gas that can serve as a source for carbon dioxide-containing gas may be, for example, approximately 5% to 20%. Furthermore, the carbon dioxide-containing gas may also contain, for example, nitrogen. It is preferable to set the bubble size and supply amount in the carbon dioxide-containing gas so that the bubbles dissolve completely before reaching the water surface, thereby minimizing losses released into the atmosphere.

[0024] Carbon dioxide-containing water is water that contains carbon dioxide in a predetermined proportion. The concentration of dissolved carbon dioxide in carbon dioxide-containing water is greater than 100 mg / L. More preferably, the concentration of dissolved carbon dioxide in carbon dioxide-containing water is greater than 200 mg / L. For example, carbon dioxide-containing water may be obtained by dissolving the above-mentioned carbon dioxide-containing gas in saltwater, such as seawater. The concentration of dissolved oxygen in carbon dioxide-containing water may be less than 3 mg / L, for example, by degassing or supplying nitrogen gas.

[0025] In supply step S11, carbon dioxide-containing gas and carbon dioxide-containing water may be supplied to a predetermined body of water in an appropriate combination. Alternatively, in supply step S11, multiple types of carbon dioxide-containing gas and carbon dioxide-containing water may be supplied to a predetermined body of water in an appropriate combination.

[0026] Furthermore, in the supply process S11, the supply pattern for supplying carbon dioxide-containing gas and carbon dioxide-containing water may be continuous or intermittent. The supply pattern may also involve supplying low concentrations of carbon dioxide-containing gas and carbon dioxide-containing water for extended periods, or supplying high concentrations of carbon dioxide-containing gas and carbon dioxide-containing water for short periods.

[0027] According to the above configuration, it is possible to induce repellent behavior in specific aquatic organisms simply by increasing the concentration of dissolved carbon dioxide in a given body of water. Therefore, a simpler technique for inducing repellent behavior in aquatic organisms can be provided.

[0028] Furthermore, for example, in the supply process S11, at least one of carbon dioxide-containing gas and carbon dioxide-containing water may be supplied during the period when a predetermined aquatic organism can be active. For example, the supply process S11 may be carried out during the period when a predetermined aquatic organism can be active, that is, during the period or time when herbivorous fish are actively feeding. As a specific example, in the case of rabbitfish and rudderfish, the time of day when they are most active is generally during the daytime. Also, in the case of rabbitfish, the main period of activity is from August to December, when there is a lot of damage to algae.

[0029] According to the above configuration, the utilization efficiency of carbon dioxide-containing gas and carbon dioxide-containing water supplied to a designated body of water can be improved.

[0030] Alternatively, for example, a fish finder may be installed in a designated body of water, and when the approach of herbivorous fish to the designated body of water is detected, the supply process S11 may be executed.

[0031] Furthermore, for example, in the supply process S11, at least one of carbon dioxide-containing gas and carbon dioxide-containing water may be supplied under conditions where sunlight reaches the algae, thereby promoting the growth of the algae through photosynthesis. In addition, nutrients that promote the growth of the algae may be further supplied at this time.

[0032] (Example configuration of carbon dioxide supply device 1) The configuration of the carbon dioxide supply device 1 that implements the carbon dioxide supply method M10 will be described with reference to Figures 2 to 5. Figures 2 to 5 are schematic diagrams showing an example of the configuration of the carbon dioxide supply device 1. As shown in Figures 2 to 5, the carbon dioxide supply device 1 includes a measuring unit 11 and a supply unit 12.

[0033] (Measuring part 11) The measuring unit 11 measures the concentration of dissolved carbon dioxide in a predetermined body of water.

[0034] Figures 2 to 5 show examples of configurations when the aquaculture farm where seaweed is cultivated corresponds to a predetermined body of water. In Figures 2 to 5, the cultivation ropes R on which the seaweed SW grows are connected to buoys F floating on the sea surface. The buoys F are moored to blocks B located on the seabed. (Note that in Figure 5, the seaweed SW and blocks B are not shown.) In other words, as shown in Figures 2 to 4, the position of the cultivation ropes R in the sea is roughly defined by the buoys F and blocks B.

[0035] The measuring unit 11 may be, for example, a carbon dioxide concentration meter that measures the concentration of dissolved carbon dioxide in water using known technology. Alternatively, the measuring unit 11 may be a carbon dioxide concentration meter installed in a predetermined body of water that monitors the concentration of dissolved carbon dioxide in that body of water. The measuring unit 11 may measure the concentration of dissolved carbon dioxide at predetermined time intervals, when a user operates the measuring unit 11, or when a measurement command is received from an external source. The measuring unit 11 may also further measure, for example, at least one of the temperature, pH (hydrogen ion concentration), and dissolved oxygen concentration in the predetermined body of water.

[0036] Furthermore, the measuring unit 11 may be moored to the float F and block B, for example, as shown in Figures 2 to 4. (Note that in Figure 5, the configuration for mooring the measuring unit 11 is not shown.) In other words, the position of the measuring unit 11 in the sea may be roughly defined by the float F and block B, for example, similar to the aquaculture rope R described above.

[0037] Furthermore, the measurement unit 11 may send and receive data with the supply unit 12 (described later) and other external devices via at least one of wired and wireless communication means. An example of data transmitted by the measurement unit 11 is the measurement result of the dissolved carbon dioxide concentration. An example of data received by the measurement unit 11 is the measurement command for the dissolved carbon dioxide concentration.

[0038] The power supply used by the measuring unit 11 may be generated using, for example, sunlight, tides, or wind power, or it may be supplied from a battery, or it may be supplied from a power cable.

[0039] (Supply section 12) The supply unit 12, referring to the measurement results from the measurement unit 11, supplies at least one of carbon dioxide-containing gas and carbon dioxide-containing water containing carbon dioxide in a predetermined proportion to a predetermined body of water, such that the dissolved carbon dioxide concentration in the body of water exceeds 100 mg / L. The supply unit 12 may be, for example, a pump that handles the supply of gases such as carbon dioxide-containing gas, or a pump that handles the supply of liquids such as carbon dioxide-containing water.

[0040] The supply unit 12 may obtain the measurement result of the dissolved carbon dioxide concentration from the measurement unit 11 and supply at least one of carbon dioxide-containing gas and carbon dioxide-containing water until the dissolved carbon dioxide concentration exceeds a predetermined concentration. Here, the predetermined concentration may be, for example, 100 mg / L as described above, and more preferably 200 mg / L. At this time, the supply unit 12 may, for example, control the amount of carbon dioxide-containing gas and carbon dioxide-containing water supplied to a predetermined water body according to the obtained measurement result.

[0041] Furthermore, the supply unit 12 may supply at least one of carbon dioxide-containing gas and carbon dioxide-containing water that have been stored in a tank or the like in advance to a predetermined body of water, or it may supply at least one of carbon dioxide-containing gas and carbon dioxide-containing water that have been generated each time to a predetermined body of water.

[0042] Furthermore, the supply unit 12 may send and receive data with the measurement unit 11 and other external devices via at least one of wired and wireless communication means. An example of data received by the supply unit 12 is the measurement result of the dissolved carbon dioxide concentration. An example of data transmitted by the supply unit 12 is an inquiry regarding the measurement result of the dissolved carbon dioxide concentration.

[0043] The power supply unit 12 may be generated using, for example, solar power, tides, or wind power, or it may be supplied from a battery, or it may be supplied from a power cable.

[0044] Here, the supply unit 12 may further include a discharge unit 121, as shown in Figures 2 to 5. The discharge unit 121 is piping for supplying at least one of carbon dioxide-containing gas and carbon dioxide-containing water to a predetermined body of water. That is, at least one of the carbon dioxide-containing gas and carbon dioxide-containing water supplied by the supply unit 12 is discharged from a discharge port in the discharge unit 121, as shown in Figures 2 to 5. Multiple such discharge ports may be installed near the seaweed SW growth site, as shown in Figures 2 to 5. Here, the supply unit 12 may individually control the amount of carbon dioxide-containing gas and carbon dioxide-containing water supplied to each of the discharge ports, for example, via a control valve provided at each of the discharge ports. In this case, for example, the carbon dioxide-containing gas and carbon dioxide-containing water may be supplied from the middle to upper reaches of the discharge port, taking into consideration the flow direction and flow velocity of the target body of water. The amount of carbon dioxide-containing gas and carbon dioxide-containing water supplied and the supply location may be set, for example, by conducting a simulation and taking into consideration the range of influence.

[0045] The other components of the supply unit 12 are the same as those described above in the explanation of the supply process S11 performed by the supply unit 12, so their explanation is omitted here. Note that all or part of the processes performed by the carbon dioxide supply device 1 may be performed in the carbon dioxide supply method M10.

[0046] (Example of a configuration that supplies carbon dioxide-containing gas to seaweed growing downwards) Figure 2 is a schematic diagram showing an example configuration of a carbon dioxide supply device 1 that supplies carbon dioxide-containing gas to seaweed growing downwards. In this example configuration, the seaweed SW grows downwards from the cultivation rope R located near the sea surface, as shown in Figure 2. For example, as shown in Figure 2, carbon dioxide-containing gas may be discharged from multiple outlets in the discharge unit 121. Here, for example, as shown in Figure 2, the outlets for the carbon dioxide-containing gas in the discharge unit 121 may be located closer to the deepest part of the range in which the seaweed SW grows. Also, the measuring unit 11 may be installed at a location further away from the outlets in a predetermined water area, such as near the water surface, as shown in Figure 2.

[0047] (Example of a configuration that supplies carbon dioxide-containing water, etc., to seaweed growing downwards) Figure 3 is a schematic diagram showing an example configuration of a carbon dioxide supply device 1 that supplies carbon dioxide-containing water to seaweed growing downwards. In this example configuration, the seaweed SW grows downwards from the cultivation rope R located near the sea surface, as shown in Figure 3. For example, as shown in Figure 3, carbon dioxide-containing water may be discharged from multiple outlets in the discharge section 121. In addition, the supply section 12 may further supply nutrients that promote the growth of algae, as described above.

[0048] (Example of a configuration that supplies carbon dioxide-containing gas to seaweed growing upwards) Figure 4 is a schematic diagram showing an example configuration of a carbon dioxide supply device 1 that supplies carbon dioxide-containing gas to seaweed growing upwards. In this example configuration, the seaweed SW is growing upwards from the cultivation rope R located in the sea, as shown in Figure 4. For example, as shown in Figure 4, carbon dioxide-containing gas may be discharged from multiple outlets in the discharge unit 121. The location of the carbon dioxide-containing gas outlets in the discharge unit 121 and the measurement unit 11 are the same as in the example configuration described with reference to Figure 2, so the explanation is omitted here.

[0049] (Example configuration of carbon dioxide supply device 1 on the water surface) Figure 5 is a schematic diagram showing an example configuration of the carbon dioxide supply device 1 on the water surface. In other words, Figure 5 corresponds to a plan view of the carbon dioxide supply device 1. In this example configuration, the multiple discharge ports of the discharge section 121 are moored to the float ball F and installed approximately parallel to the aquaculture rope R, as shown in Figure 5. (Note that in Figure 5, the supply section 12 and the parts of the discharge section 121 corresponding to the piping connected to the supply section 12 (i.e., parts other than the discharge ports) are omitted from the illustration.) In addition, as shown in Figure 5, multiple carbon dioxide concentration meters, which are an example of the measurement section 11, are installed around the aquaculture farm.

[0050] [Examples of implementation using software] The function of the carbon dioxide supply device 1 (hereinafter referred to as "the device") is a program that causes a computer to function as the device, and can be realized by a program that causes a computer to function as each control block of the device (in particular, each component that controls the measuring unit 11 and the supply unit 12).

[0051] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., memory) as hardware for executing the program. By executing the program using this control device and storage device, the functions described in each of the embodiments are realized.

[0052] The above program may be recorded on one or more computer-readable recording media, not temporary ones. These recording media may or may not be provided by the above device. In the latter case, the program may be supplied to the above device via any wired or wireless transmission medium.

[0053] Furthermore, some or all of the functions of each of the above control blocks can also be realized by logic circuits. For example, an integrated circuit in which logic circuits functioning as each of the above control blocks are formed is also included in the scope of the present invention. In addition, it is also possible to realize the functions of each of the above control blocks by, for example, a quantum computer.

[0054] Furthermore, each process described in the above embodiments may be performed by AI (Artificial Intelligence). In this case, the AI ​​may operate on the control device described above, or it may operate on other devices (for example, an edge computer or a cloud server).

[0055] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0056] 〔summary〕 A carbon dioxide supply method according to Embodiment 1 of the present invention includes a supply step of supplying at least one of a carbon dioxide-containing gas and carbon dioxide-containing water containing carbon dioxide in a predetermined proportion to a predetermined body of water such that the concentration of dissolved carbon dioxide in the body of water exceeds 100 mg / L.

[0057] According to the above configuration, it is possible to induce repellent behavior in specific aquatic organisms simply by increasing the concentration of dissolved carbon dioxide in a given body of water. Therefore, a simpler technique for inducing repellent behavior in aquatic organisms can be provided.

[0058] In the carbon dioxide supply method according to aspect 2 of the present invention, in addition to the configuration of the carbon dioxide supply method according to aspect 1, the concentration of carbon dioxide in the carbon dioxide-containing gas exceeds 400 ppm.

[0059] According to the above configuration, repellent behavior can be induced using a carbon dioxide-containing gas.

[0060] In the carbon dioxide supply method according to embodiment 3 of the present invention, in addition to the configuration of the carbon dioxide supply method according to embodiment 1, the concentration of dissolved carbon dioxide in the carbon dioxide-containing water exceeds 100 mg / L.

[0061] According to the above configuration, repellent behavior can be induced using carbon dioxide-containing water.

[0062] In the carbon dioxide supply method according to aspect 4 of the present invention, in addition to the configuration of the carbon dioxide supply method according to any one of aspects 1 to 3 above, at least one of the carbon dioxide-containing gas and the carbon dioxide-containing water is supplied in the supply step at a time when a predetermined aquatic organism can be active.

[0063] According to the above configuration, the utilization efficiency of carbon dioxide-containing gas and carbon dioxide-containing water supplied to a designated body of water can be improved.

[0064] A carbon dioxide supply device according to aspect 5 of the present invention comprises a measuring unit for measuring the concentration of dissolved carbon dioxide in a predetermined body of water, and a supply unit that, referring to the measurement results from the measuring unit, supplies at least one of a carbon dioxide-containing gas and carbon dioxide-containing water containing carbon dioxide in a predetermined proportion to the predetermined body of water so that the concentration of dissolved carbon dioxide in the body of water exceeds 100 mg / L.

[0065] The above configuration produces the same effects as in the first embodiment. [Examples]

[0066] One embodiment of the present invention is described below.

[0067] Figure 6 is a schematic diagram showing the configuration of the carbon dioxide supply device 1 according to this embodiment. In this embodiment, a tank AQ with a width of 880 mm, a depth of 280 mm, and a height of 325 mm was prepared. Figure 6 is a schematic diagram of the tank AQ viewed from the side, with dimensions of 880 mm width and 325 mm height. Seawater was filled into the tank AQ, and the measuring unit 11 and the supply unit 12 were installed. As shown in Figure 6, the supply unit 12 was installed near one end of the tank AQ and near the bottom of the tank AQ, and the measuring unit 11 was installed near the other end of the tank AQ and near the water surface of the tank AQ. The supply unit 12 used had an air stone-shaped outlet at the discharge unit 121.

[0068] Six gobies of the same size were released into tank AQ as test fish and left to stand for approximately 30 minutes. Then, air was supplied from supply unit 12 to the seawater in tank AQ at a flow rate of 0.5 L / min for 60 minutes. After the start of air supply, the health status of the test fish was recorded every 5 minutes. After another 30 minutes of standing, carbon dioxide was supplied from supply unit 12 to the seawater in tank AQ at a flow rate of 0.5 L / min for 60 minutes. Even after the start of carbon dioxide supply, the health status of the test fish was recorded every 5 minutes. The arrows in Figure 6 indicate the expected movement paths of the carbon dioxide and air supplied from supply unit 12 to the measurement unit 11. Regarding the positioning area where the test fish are located in tank AQ, three areas were defined by dividing tank AQ into three sections, as shown in Figure 6. The names of the localization areas were designated as No. 1, No. 2, and No. 3, in order from the supply unit 12 side to the measurement unit 11 side.

[0069] Figure 7 shows the change in dissolved carbon dioxide concentration over time when air or carbon dioxide was supplied to seawater in the AQ tank, respectively. When air was supplied to the seawater in the AQ tank, the dissolved carbon dioxide concentration remained approximately 0 mg / L, as shown in Figure 7. On the other hand, when carbon dioxide was supplied to the seawater in the AQ tank, as shown in Figure 7, the dissolved carbon dioxide concentration began to rise about 5 minutes after the start of supply, exceeded 100 mg / L between 10 and 15 minutes after the start of supply, and then exceeded 200 mg / L within 20 minutes after the start of supply.

[0070] Figure 8 shows the changes in the number of test fish in the AQ tank over time. Five minutes after the start of carbon dioxide supply to the seawater in the AQ tank, multiple test fish were observed in location area No. 1 (the area where carbon dioxide is directly discharged), as shown in ST1 of Figure 8. Subsequently, 15 minutes after the start of supply, as shown in ST2 of Figure 8, the number of test fish observed in location area No. 1 decreased, while the number of test fish observed in location area No. 3 increased.

[0071] Table 1 below shows the ranks used to classify the health status of the test fish recorded in this embodiment. As shown in Table 1, the fish were classified into six levels from 0 to 5. As shown in Table 1, the lower the rank, the worse the health status of the test fish.

[0072] Table 1: Ranking system for classifying the health status of test fish.

[0073] [Table 1] Figure 9 shows the changes over time in the localization area and health status of the test fish in the AQ tank. The upper part of Figure 9 shows the changes over time in the number of test fish in each localization area when carbon dioxide was supplied to the seawater in the AQ tank. As shown in the upper part of Figure 9, a tendency for the test fish to move from localization area No. 1 to No. 3 was observed 15 to 25 minutes after the start of carbon dioxide supply. At this time, it is possible that the test fish exhibited avoidance behavior towards the supplied carbon dioxide.

[0074] The lower part of Figure 9 shows the change in the health status rank of the test fish over time when air or carbon dioxide was supplied to the seawater in the AQ tank, respectively. When air was supplied to the seawater in the AQ tank, the health status rank of the test fish remained constant at 5 (healthy), as shown in the lower part of Figure 9. On the other hand, when carbon dioxide was supplied to the seawater in the AQ tank, the health status rank of the test fish decreased over time from 5 (healthy), as shown in the lower part of Figure 9. Furthermore, approximately 15 to 25 minutes after the start of carbon dioxide supply, the fish began to exhibit temporary paralysis or near-fainting states, such as slowed movement, sudden abnormal behavior, and thrashing around while breathing before becoming motionless.

[0075] Furthermore, regarding the number of test fish in each location area shown in the upper part of Figure 9, the range in which the behavior of the test fish could be evaluated was approximately 25 minutes after the start of carbon dioxide supply. After approximately 25 minutes from the start of carbon dioxide supply, abnormal behavior and paralysis occurred in the test fish, making it difficult to evaluate the presence or absence of avoidance behavior from the location areas of the test fish. [Explanation of Symbols]

[0076] 1. Carbon dioxide supply device 11 Measuring part 12 Supply section 121 Discharge part

Claims

1. The process includes supplying at least one of a carbon dioxide-containing gas and / or carbon dioxide-containing water to a designated body of water such that the dissolved carbon dioxide concentration in the body of water exceeds 100 mg / L. Methods for supplying carbon dioxide.

2. The concentration of carbon dioxide in the carbon dioxide-containing gas exceeds 400 ppm. The method for supplying carbon dioxide according to claim 1.

3. The concentration of dissolved carbon dioxide in the aforementioned carbon dioxide-containing water is greater than 100 mg / L. The method for supplying carbon dioxide according to claim 1.

4. In the supply process, at least one of the carbon dioxide-containing gas and the carbon dioxide-containing water is supplied at a time when a predetermined aquatic organism can be active. A method for supplying carbon dioxide according to any one of claims 1 to 3.

5. A measuring unit for measuring the concentration of dissolved carbon dioxide in a designated body of water, The system includes a supply unit that, based on the measurement results from the measurement unit, supplies at least one of a carbon dioxide-containing gas and / or carbon dioxide-containing water containing carbon dioxide in a predetermined proportion to the predetermined water body such that the dissolved carbon dioxide concentration in the water body exceeds 100 mg / L. Carbon dioxide supply device.

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