JPH099819A - Breeding of marine life requiring carbon dioxide - Google Patents

Abstract

PURPOSE: To breed coral, marine agar, etc., by supplying a gas containing carbon dioxide gas into seawater of an artificial breeding system and controlling the pH of the seawater in alkaline side. CONSTITUTION: A coral 4 is placed on the bottom of a water tank 1, seawater 5 is introduced into the tank and the breeding condition is set to 25 deg.C, 50% relative humidity and pH 8.2. The partial pressure of carbon dioxide gas in the mixed gas to be blown into the seawater 5 is controlled to 1,200-1,500ppm by a gas supplying apparatus 3 and a definite amount of the produced mixed gas is introduced into the seawater 5 through a pipe 3c. A pH-controlling apparatus 2 is started immediately after starting the breeding to control the pH of the seawater 5 between 8.15 and 8.25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rearing marine organisms that require carbon dioxide such as coral and seaweed in seawater of an artificial rearing system such as an aquarium.
The present invention relates to a method for rearing marine organisms that require carbon dioxide that can be reared with the intention of multiplying.

[0002]

2. Description of the Related Art In an artificial breeding system for aquatic organisms such as an aquarium for appreciation, it has been conventional to supply a gas containing carbon dioxide in water by a method such as bubbling in order to promote photosynthesis of aquatic plants such as aquatic plants. It is done from. In addition, when the carbon dioxide supply increases in the conventional artificial rearing system,
It is also known to adversely affect aquatic life. Therefore, the supply of carbon dioxide is 20 to 30 as the concentration in water.
The present situation is that it is performed in the ppm range.

The supply of such low concentration of carbon dioxide cannot increase the concentration of carbon dioxide beyond the concentration usually dissolved in seawater, rivers, etc., and the active growth of aquatic organisms in a short period of time. The reality is that proliferation and the like are not intended.

By the way, coral, which is demanded for appreciation, is actually in a very small supply due to legal regulations, and it has been conventional to stabilize the supply of seaweed and the like. Is desired.

Therefore, among aquatic organisms, it is desired to develop a method for growing and / or multiplying seaweeds, which require carbon dioxide, and marine organisms such as corals in an artificial breeding system. However, it is necessary to consider various environmental factors related to such breeding, including the composition of components in seawater, and control is performed by selecting factors for obtaining a desired effect from all of these environmental factors. This is difficult in an artificial breeding system. For example, in an aquarium or the like, it is considered to approximate the natural seawater conditions as much as possible. For this reason, only fresh seawater supply, seawater temperature control, etc. are being carried out.For example, in the case of intentional active growth / proliferation of marine organisms that require carbon dioxide, what environmental factors should be selected The reality is that much consideration is not given to whether or not the control should be carried out dynamically.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for rearing a marine organism requiring carbon dioxide, which enables a marine organism requiring carbon dioxide to be actively grown and propagated. Especially.

[0007]

Means for Solving the Problems As a result of intensive studies in view of the above problems, the present inventors have found that a large amount of carbon dioxide-containing gas is supplied by controlling the pH of seawater in an artificial breeding system to be alkaline. It was found that the marine organisms demanding carbon dioxide do not adversely affect the growth of the marine organisms demanding carbon dioxide, and the growth of marine organisms demanding carbon dioxide is promoted in a short period of time, and thus the proliferation is also promoted, and the present invention has been completed. That is, according to the present invention, a method for feeding marine organisms requiring carbon dioxide is provided, which comprises supplying a gas containing carbon dioxide to seawater of an artificial breeding system, and controlling the pH of the seawater to be alkaline. To be done.

Hereinafter, the present invention will be described in more detail. With the marine organisms that require carbon dioxide to be reared in the rearing method of the present invention, photosynthesis is performed by carbon dioxide, seaweeds that can promote growth and proliferation, and photosynthesis by carbon dioxide and calcification that forms a skeleton are performed. Coral and the like can be mentioned. In particular, by making the concentration of carbon dioxide higher than the concentration usually dissolved in natural seawater, it is most suitable for the breeding of corals and the like, in which the growth / proliferation effects are remarkable in a short period of time.

In the rearing method of the present invention, it is essential to supply a gas containing carbon dioxide to the seawater of the artificial rearing system and to control the pH of the seawater to be alkaline.

The above-mentioned artificial breeding system is a system in which seawater is introduced into an ordinary aquarium or the like, and in the cultivation of fish and shellfish, etc., a part of the sea is substantially divided and always communicated with the sea. Not meant to be.

The method of supplying the gas containing carbon dioxide to the seawater of the artificial breeding system is not particularly limited, and mixed air in which carbon dioxide from the carbon dioxide cylinder is mixed with air to increase the carbon dioxide concentration is obtained. It can be carried out by a known method of supplying, etc. In particular, it is preferable to supply while controlling the carbon dioxide concentration and the supply amount, and it is preferable to control the carbon dioxide concentration in the seawater of the artificial breeding system to be a desired concentration required by the marine organisms to be raised. Such control is not necessarily intended to always supply a constant amount of gas containing a constant concentration of carbon dioxide, but it does not necessarily mean that the amount of carbon dioxide consumed by the marine organisms being raised is taken into account in the photosynthesis. It also includes control over time in consideration of the relationship with the irradiation amount. The selection of the carbon dioxide concentration to be supplied and the supply amount may be carried out by appropriately empirically determining the carbon dioxide concentration and the like required by the marine organisms to be raised. For example, corals are grown and propagated in a short period of time. If intended, the carbon dioxide concentration in seawater is 70-
It is preferable to control it to be 200 ppm. At this time, the upper limit of the carbon dioxide concentration in seawater is determined by p
In H control, it was determined in consideration of the fact that when an alkaline aqueous solution is added, the amount of addition increases and salts such as carbonates precipitate, or seawater is diluted too much and the salt concentration in seawater changes significantly. Preferably.

The carbon dioxide-containing gas supplied to the seawater can be appropriately selected depending on the desired carbon dioxide concentration, supply amount, supply period, etc., so as to contain oxygen necessary for respiration. Specifically, for example, a mixed gas from air and a commercially available CO ₂ supply cylinder or the like can be used.

On the other hand, the pH of the seawater is controlled to be alkaline by acidification of the carbon dioxide, particularly by supplying the carbon dioxide so as to have a concentration higher than the concentration of carbon dioxide dissolved in normal seawater. This is to prevent the above and obtain a desired effect. The method for controlling the pH to such an alkalinity is not particularly limited, but a method that can easily control the pH, does not adversely affect the marine organisms to be raised, and does not significantly change the composition of seawater is desirable. Specifically, a method of adding an alkaline aqueous solution such as a sodium hydroxide aqueous solution, a potassium hydroxide aqueous solution, a calcium hydroxide aqueous solution, and a magnesium hydroxide aqueous solution to seawater is preferable. At this time, normal seawater contains a large amount of sodium salt (about 3%,
Since it is contained in an amount of 0.5 mol / l), it is particularly preferable to use an aqueous solution of sodium hydroxide among the alkaline aqueous solutions from the viewpoint that it does not significantly affect the composition of seawater.

To add the alkaline aqueous solution, for example, a pH electrode for detecting pH is kept in seawater of an artificial breeding system, and the pH of the seawater is detected constantly or with time, and a desired pH value or pH range is obtained. It can be carried out using a device or the like that can be controlled so that an amount of alkaline aqueous solution can be added. At this time, the control associated with the addition of the alkaline aqueous solution is a method of controlling only the addition amount while keeping the concentration constant, a method of determining the addition amount per time, a method of controlling only the concentration, the concentration and the addition amount. Any of the above two methods may be used. In the control accompanying the addition of such an alkaline aqueous solution, the addition amount of the alkaline aqueous solution,
That is, when the water content increases, the dilution rate of seawater increases,
In particular, the salt concentration in seawater changes significantly, which may adversely affect the marine life to be raised. Therefore, when the pH is controlled by adding an alkaline aqueous solution, the amount of water increase in seawater due to the addition of the alkaline aqueous solution and the amount of water decrease in seawater due to natural evaporation of seawater in the artificial breeding system are controlled to be substantially constant. More preferably. Specifically, for example, the amount of evaporation of water from the artificial breeding system per unit time that changes depending on the conditions such as the ambient environment is measured in advance, and when an alkaline aqueous solution having a substantially equal volume to it is added, the required amount of OH ~ Examples thereof include a method of controlling both the concentration and the addition amount of the alkaline aqueous solution so that ions are added and pH is adjusted. However, the present invention is not limited to this, for example, by keeping the ambient environment (temperature, humidity, etc.) of the artificial breeding system substantially constant, and controlling the evaporation amount of water from the artificial breeding system per unit time. If it is, the amount of water added per unit time is estimated to be approximately the same as the amount of evaporation, and the alkaline aqueous solution concentration is determined to a predetermined concentration in advance taking into account the pH change at that time. It can also be performed by a control method or the like.

In the pH control, the pH value of seawater to be set is alkaline and can be appropriately selected according to the kind of marine organisms to be raised. For example, when corals are bred, if the pH is 7.6 or less, the coral skeleton may be dissolved, so it is desirable to set the pH to a value higher than 7.6. More preferably, it is desirable to set the pH to the same value as that of ordinary surface seawater, that is, 8.2, or a pH value and a pH range around it.

In the breeding method of the present invention, the gas containing carbon dioxide can be supplied and the pH can be controlled. Naturally, however, in order to allow a marine organism requiring carbon dioxide to perform photosynthesis, It is necessary to perform light irradiation. The light irradiation may be sunlight or artificial light, and the light irradiation amount and irradiation time can be appropriately selected according to the type of marine organism to be raised, the desired growth / proliferation ratio, and the like. . Further, the breeding temperature can also be appropriately selected according to the type of marine organism to be breeded.

In addition, in the artificial rearing system of the present invention, it is preferable that the composition of the electrolyte or the like in seawater is not changed so much, as also considered in the pH control. The easiest method for preventing such a composition change is to replace seawater, which has been bred conventionally, with fresh seawater on a regular basis. However, in the present invention, it is an essential requirement that the artificially rearing seawater is dissolved in a high concentration of carbon dioxide, which is preferably higher than usual. Therefore, replacement with fresh seawater is performed once a week to one month. It is preferable to carry out so that an amount corresponding to 5 to 20% of the total volume of the water tank is exchanged at a frequency of times. Particularly as the alkaline aqueous solution,
As described above, when using an aqueous solution of sodium hydroxide, changes in the composition of seawater have little effect on marine organisms, so once every six months to one year, the amount of seawater equivalent to all seawater in the artificial breeding system is used. It suffices to exchange at the above-mentioned preferable exchange rate so that the water is exchanged with fresh seawater.

[0018]

In the breeding method of the present invention, the supply of gas containing carbon dioxide and the pH control to alkalinity are selectively performed. Therefore, in seawater of artificial breeding system, coral and seaweed which require carbon dioxide. Etc. can be effectively bred even when they are intended for active growth / proliferation. Therefore, it is useful for efficient production of seaweeds and the short-term growth and multiplication of corals and the like.

[0019]

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

In FIG. 1, reference numeral 10 is a schematic view showing an embodiment of a breeding system for carrying out the breeding method of the present invention. The breeding system 10 includes a water tank 1 having a capacity of 60 liters, a pH control device 2, and a gas supply device 3 containing carbon dioxide, and a lighting device for irradiating light into the water tank is provided above the water tank 1. is set up.

The pH control device 2 is connected to a pH electrode 2a installed in a state where a part thereof is held in the seawater 5 and a tank 2b containing a sodium hydroxide aqueous solution adjusted to a predetermined concentration in advance. ing. Further, a pipe 2c for dropping an appropriate amount of the sodium hydroxide aqueous solution in the tank 2b into the seawater 5 is provided. In this pH control device 2, p
The pH of seawater 5 measured by the H electrode 2a is detected, and the pH is detected.
A control mechanism (not shown) is provided for automatically dropping the amount of sodium hydroxide aqueous solution required to adjust the value to a desired pH value from the tank 2b into the seawater 5 through the pipe 2c.

On the other hand, the gas supply device 3 is connected to a cylinder 3a filled with carbon dioxide and an air pump 3b. A pipe 3c for supplying a mixed gas of carbon dioxide and air into the seawater 5 by bubbling is connected. A cylinder 3 is provided in the gas supply device 3.
A control mechanism (not shown) that mixes the carbon dioxide from a and the air from the air pump 3b so as to have an appropriate carbon dioxide partial pressure and automatically supplies a desired amount of mixed gas to the seawater 5 through the pipe 3c. ) Is provided.

Next, a specific example of breeding corals using the breeding system 10 will be described. The breeding conditions were set in advance to 25 ° C. and 50% humidity, and the evaporation amount of seawater per unit time at this time was measured. In addition, it suppresses the pH decrease of seawater 5 and has a pH of 8.
The concentration of the sodium hydroxide aqueous solution was adjusted to 0.2 m so that the amount of the sodium hydroxide aqueous solution that was estimated to be necessary to control the concentration to about 2 was approximately equal to the measured evaporation amount of seawater.
It was determined to be ol / liter and filled in the tank 2b. In determining the concentration, the amount of carbon dioxide consumed by corals and the partial pressure of carbon dioxide supplied to seawater were considered.

First, the inside of the room was controlled at 25 ° C. and a humidity of 50%, and a coral (weeding rice) 4 having a weight of 50 g was placed on the bottom of the water tank 1, and 40 liters of seawater 5 was introduced. Next, the carbon dioxide partial pressure is controlled by the gas supply device 3 so that the carbon dioxide concentration of the mixed gas blown into the seawater 5 is in the range of 1200 to 1500 ppm, and a certain amount of the mixed gas is introduced into the seawater 5 from the pipe 3c. Breeding was performed while feeding. Simultaneously with the start of breeding, the pH controller 2 was operated to control the pH of the seawater 5 to be 8.15 to 8.25.
At this time, the amount of the sodium hydroxide aqueous solution that is automatically added is approximately 10 to 2 which is approximately equal to the amount of water evaporated from the seawater 5.
It was 0 ml / day. No salt precipitation was observed due to the addition of the aqueous sodium hydroxide solution. The concentration of carbon dioxide in water dissolved in the seawater 5 is considered to be approximately in equilibrium with the concentration of carbon dioxide in the mixed gas to be blown, and the value is estimated to be 70 to 100 ppm. The light irradiation was performed with a light intensity of 100 μE / m ² / s, light for 12 hours, and dark for 12 hours.

After breeding for 10 days, the coral was taken out from the aquarium 1, the weight was measured and compared with the weight before breeding, and an increase of 1.2 g was recognized. From this result,
It was found that the growth rate was about three times that of normal seawater (natural) growth.

As a comparison, when the animal was similarly bred without using the pH control device 2, the weight was hardly increased because the skeleton was decreased due to the decrease in pH.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a breeding system used in an example of the present invention.

[Explanation of symbols]

 1 Water tank 2 pH control device 3 Gas supply device 4 Coral 5 Seawater

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C02F 1/66 530 C02F 1/66 530L 530P 1/68 510 1/68 510J 520 520C

Claims (3)

[Claims] 1. A method for rearing marine organisms requiring carbon dioxide, which comprises supplying a gas containing carbon dioxide to seawater of an artificial rearing system and controlling the pH of the seawater to be alkaline. 2. The pH control is performed by adding an alkaline aqueous solution, and the amount of water increase in seawater due to the addition of the alkaline aqueous solution and the amount of water decrease in seawater due to natural evaporation of seawater in an artificial breeding system. The breeding method according to claim 1, wherein the breeding is controlled to be substantially constant. 3. The breeding method according to claim 1, wherein the marine organisms that require the carbon dioxide are corals.