JPH0665266B2 - Fish swimming blocker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a device for blocking the swimming of fish, which prevents fish from entering and exiting a predetermined water area.

[Conventional technology]

Conventionally, various methods have been adopted to prevent invasion of fish into and out of a given water area, such as aquaculture, for the cultivation of fish. However, the net itself is easily damaged by wind and waves, and it requires a lot of labor and cost to maintain and maintain the net. Therefore, recently, a method of utilizing the threatening effect on fish without using the net has been considered. There is.

As one example, there is a method using an electric screen proposed by the applicant of the present invention, in which a plurality of electrode rows are arranged in water and different potentials are applied to each of these electrode rows by a power source for generating an electric screen, An electric screen having a predetermined electric field strength is formed between the rows, and the fish that has entered the electric screen is electrically stimulated by the electric screen to intimidate the fish and block the swimming of the fish. (See Japanese Patent Application No. 61-12677, the specification and drawings.) [Problems to be solved by the invention] However, in the case of the above-mentioned electric screen, direct electrical stimulation is applied to the fish body, and the fish immediately repels. Therefore, on the other hand, it has a very high blocking effect, but on the other hand, there is a problem that a large number of fish bodies that fall into a paralyzing state, an asphyxia state and even a death occur due to electrical stimulation of the electric screen, which causes damage to the fish body. In the case of aquaculture, immediately after the fry are released to a farm surrounded by an electric screen, the fry tend to swim violently and plunge into the high electric field strength region of the electric screen, resulting in the inconvenience that many fry are damaged. .

Therefore, the present invention has been made with the above points in mind, and by utilizing the threatening effect of sound on fish, the number of fish entering the electric screen can be reduced, and damage to the fish body due to electrical stimulation of the electric screen can be suppressed. The purpose is to

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the fish swimming blocker of the present invention forms a electric screen between a plurality of electrode rows arranged in water and different potentials applied to the respective electrode rows. A power source, a plurality of underwater speakers arranged close to the electric screen, an oscillating means for giving an oscillating signal to each of the speakers to cause the underwater speakers to produce sound, an energization from the power source, and the oscillating means And a control device for alternately performing the operation of.

[Action]

In the fish swimming blocker of the present invention configured as described above, the electric power is supplied from the power source forming the electric screen and the operation of the oscillating means for causing the underwater speaker to sound is alternately performed by the control device. It is possible to significantly reduce the number of fish that enter in close proximity to the fish, control damage to the fish, and reduce power consumption.

〔Example〕

Reference Example 1 First, FIGS. 1 to 3 showing Reference Example 1 will be described.

In FIG. 1 showing the schematic configuration of the apparatus, (1a), (1b)
Is two electrode rows, each of which is formed by arranging a plurality of rod-shaped electrodes in water at substantially equal intervals.
a) and (1b) are arranged at a fixed distance.

(2) a power source for applying different potentials to the two electrode arrays (1a) and (1b) to form an electric screen (3) having a predetermined electric field strength between the two electrode arrays (1a) and (1b), (4) Is a plurality of underwater speakers arranged close to the other electrode array (1b),
Reference numeral (5) is an oscillating means, which outputs an oscillating signal to each underwater speaker (4) and causes each underwater speaker (4) to generate a sound of a predetermined frequency.

At this time, the generation condition of the electric screen (3) and the sound generation condition of the underwater speaker (4) described above are shown in FIG.
As shown in Fig. 2, the power source (2) is continuously energized to continuously generate the electric screen (3), and as shown in Fig. 2 (b), the oscillating means (5) is continuously operated. Then, each underwater speaker (4) continuously produces sound.

Then, the electrode arrays (1a), (1b) and the underwater speaker (4) are arranged in the experimental water tank, and the red sea bream fish 200 is placed in the water tank.
When the tail was discharged, the relationship between the elapsed time after discharge and the number of paralyzed fish under the conditions of generation of the electric screen (3) and the sound condition of the underwater speaker (4) was examined, and the solid line in FIG. It became as shown in. For comparison, the relationship in the case where the sound generation of the underwater speaker (4) is stopped and only the electric screen (3) is formed is shown by the one-dot chain line in FIG.

Therefore, as is clear from FIG. 3, for about 30 minutes immediately after the discharge, the case of the combined sound of the electric screen (3) and the underwater speaker (4) is the case of the electric screen (3) only. Compared to, the number of paralyzed fish was significantly reduced, because the threat of sound prevented the fry from approaching the electric screen (3).

In addition, about 30 minutes after the release, the number of paralyzed fish seems to be the same regardless of whether the sound is combined with the electric screen (3) and the underwater speaker (4) or only the electric screen (3). Gradually decreases.

By the way, in the case of multiple cases, as shown in Fig. 3, the number of paralyzed fish increases temporarily after about 10 minutes from the release, but this is because the juveniles are different from the sound from the underwater speaker (4) in environmental noise. This shows that the intimidating effect of the sound is slightly diminished, but the number of paralyzed fish is still smaller than in the case where only the electric screen (3) is used.

However, the curve in FIG. 3 was obtained by connecting the total values of the number of paralyzed fish every 5 minutes.

As described above, according to the first reference example, the electric screen (3) is continuously generated, and at the same time, the underwater speakers (4) provided in the vicinity of the electric screen (3) continuously generate sound. As compared with the case where only the electric screen (3) is generated without generating a sound, the number of fish approaching and entering the electric screen (3) can be significantly reduced due to the intimidating effect of the sound, and the high cutoff is achieved. The effect can be obtained, and at the same time, the damage to the fish body due to the electric stimulation of the electric screen (3) can be suppressed, which is extremely effective in fish farming.

Reference Example 2 Next, FIGS. 4 to 6 showing Reference Example 2 will be described. The configuration of the device used in Reference Example 2 is the same as that shown in FIG.

The difference between this reference example 2 and the above reference example 1 is that
As a generation condition of the electric screen (3), FIG.
As shown in, the power source (2) is intermittently energized and the electric screen (3) is intermittently generated. The sound generation condition of the underwater speaker (4) is the same as in the reference example 1. As shown in FIG. 4 (b), the oscillating means (5) is continuously operated, and the underwater speakers (4) continuously generate sound.

Then, similar to Reference Example 1, regarding the relationship between the elapsed time after release and the number of paralyzed fish and the cumulative number of passed fish in the electric screen area when 200 fry of red sea bream were released using an experimental water tank Upon examination, the results were as shown in FIG. 5 and FIG. 6, respectively.

The power supply (2) is energized and stopped for 2 seconds and 6 respectively.
Seconds

First, the fifth showing the relationship between the elapsed time after release and the number of paralyzed fish
In the figure, the solid line shows the result in the case of the composite of the sound by the intermittent electric screen (3) and the underwater speaker (4),
The one-dot chain line and the two-dot chain line show the results when the electric screen (3) is continuously generated and when the electric screen (3) is intermittently generated, respectively, and FIG. As can be seen from the above, the number of paralyzed fish is significantly reduced in the combined case compared to any other case, and even if the peak values of the number of paralyzed fish are compared, in the combined case, only the electric screen (3) is continuous. It is about 1/4 of the case of occurrence.

At this time, even when only the electric screen (3) is generated, the number of paralyzed fish is smaller in the intermittent occurrence than in the continuous occurrence. This is because there are fry that recover from paralysis and escape by themselves.

The curve in FIG. 5 is obtained by connecting the total values of the number of paralyzed fish every 5 minutes.

Next, in FIG. 6 showing the relationship between the elapsed time after release and the cumulative number of passing fishes, the solid line shows the result in the case of compounding.
The dashed-dotted line and the two-dotted dashed line show the results in the natural state in which neither the electric screen (3) nor the sound from the underwater speaker (4) is generated, and when the electric screen (3) is generated intermittently, respectively. As shown in FIG. 6, in the case of the composite, the cumulative number of passing fishes is smaller than in the case of intermittent occurrence of only the electric screen (3), and due to the combination of the electric screen (3) and the sound, A cutoff rate of 90% or more is obtained, and the sound intimidating effect is remarkably exhibited.

The relationship between the elapsed time after release and the cumulative number of passing fish was also examined when only the electric screen (3) was continuously generated. In this case, the cumulative number of passing fish is almost zero, and is almost 100.
While a blocking effect of 10% is obtained, the number of paralyzed fish is the highest as described above.

Therefore, according to the reference example 2, the reference example 1 described above is used.
The same effect as can be obtained, of course, by intermittently energizing the power source (2) for electric screen generation,
It is possible to reduce the power consumption as compared with the case where the communication energization is performed.

(Embodiment) Next, FIGS. 7 to 10 showing an embodiment will be described. The configuration of the apparatus used in Example 3 is
This is the same as FIG. 1 described above.

First, FIG. 7 showing a block diagram of the control device will be described.

In FIG. 7, (6) is a power source for driving the oscillating means (5), (7) is a switching circuit, and the output of the power source (2) for generating the electric screen (3) is output from both electrode arrays (1a). ), (1b), and the output of the power supply (6) for driving the oscillating means (5) is supplied to the oscillating means (5), and both power supplies (2) are supplied by a command signal from a timer circuit described later. , (6) output supply is switched alternately.

(8) is a control power supply, and (9) is a timer circuit driven by the control power supply (8), which outputs a command signal for a switching command to the switching circuit (7). The output timing of the command signal is variable.

Then, with the control device shown in FIG. 7, as the generation condition of the electric screen (3) and the sound generation condition of the underwater speaker,
As shown in FIGS. 8 (a) and 8 (b), the oscillating means (5) is stopped when the power source (2) is energized and stopped.
Control so that each operating state is achieved.

Then, in the same manner as in Reference Example 1, using the experimental water tank, when 200 fry of red sea bream were released, the relationship between the elapsed time after the release and the number of approaching fish to the electric screen area was examined, As shown in FIG.

The power supply periods of the power supplies (2) and (6) are 2
Seconds and 8 seconds.

In FIG. 9, the solid line shows the result in the case of the intermittent composite in which the electric screen (3) and the sound from the underwater speaker (4) are alternately intermittently intermittently, and the right down chain line and the right upper chain line are intermittently electric. The results are shown respectively when only the screen (3) is generated and when only the sound from the underwater speaker (4) is generated. As can be seen from FIG. Compared to either case, the number of approaching fish is significantly reduced, which shows that the number of fish invading the electric screen (3) is inevitably reduced, and the time until the number of approaching fish becomes zero is compared. However, the combined case is shorter than the case of intermittent occurrence of only the electric screen (3), and in the case of the combined case, a sufficiently high blocking effect is obtained and the number of paralyzed fish due to electrical stimulation is increased. It can be reduced.

At this time, in the case of only sound, the number of approaching fish immediately after the release is small, but the number of approaching fish gradually increases with the lapse of time due to the habituation to the sound.

Next, the electric screen (3) and the underwater speaker (4)
And the elapsed time since the generation of both sounds was stopped,
The relationship between the number of fish passing through the electric screen area and the number of passing fish was examined, and the result was as shown in FIG. 10. In FIG. 10, the solid line, the one-dot chain line and the two-dot chain line are respectively the 9th and 9th lines.
As in the case of the figure, the results for the composite case, the screen (3) only, and the sound only are shown.

At this time, as can be seen from FIG. 10, in the case of the composite, the fish started to pass through the electric screen area about 30 minutes after the sound from the electric screen (3) and the underwater speaker (4) was stopped. However, even if the sound from the electric screen (3) and the underwater speaker (4) is stopped, the blocking effect continues for about 30 minutes.

On the other hand, in the case of only the electric screen (3), the interruption effect lasts for about 10 minutes after the electric screen (3) is stopped as shown in FIG. , No persistence of blocking effect is seen.

In this way, by alternately interrupting the sounds from the electric screen (3) and the underwater speaker (4), a sufficiently high blocking effect can be obtained, and at the same time, the fish body can be surely protected from electrical stimulation. Therefore, when the energization time of the power source (2) for generating the electric screen (3) is t and the energization time of the power source (6) for driving the oscillating means (5) is t ', D = t / A power reduction rate D approximately represented by (t + t ') can be achieved, and both power sources (2), (6)
Power consumption can be reduced to t / (t + t ') when both are continuously operated. Considering the continuity of the interruption effect shown in Fig. 10, simultaneous stop of both power supplies (2), (6) It is possible to reduce the power consumption at any time by providing a period.

Therefore, according to the embodiment, the same effect as that of the reference example 1 can be obtained, and the power consumption can be reduced as compared with the cases of the reference example 1 and the reference example 2 described above.

When applied to an ocean farm for large-scale aquaculture, as shown in Fig. 11, both electrode rows (1a) and (1b) are arranged so as to surround a predetermined sea area, and one electrode is used. For example, two underwater speakers (4) are attached to the rod-shaped electrodes forming the row (1b) by a fixture (10), and the above-described embodiment is used as the generation condition of the electric screen and the sound generation condition of the underwater speaker (4). It is only necessary to generate an electric screen and sound according to the conditions of 1. above, which can prevent the invasion of foreign enemy fish in the open sea area and protect the cultured fish in the marine ranch. Protects against damage from electrical stimulation.

Needless to say, three or more electrode rows may be provided.

〔The invention's effect〕

Since the present invention is configured as described above, it has the effects described below.

Since electricity is supplied from the power source forming the electric screen and the operation of the oscillating means for making a sound from the underwater speaker is alternately performed by the control device, it is possible to significantly reduce fish that enter the electric screen and enter. It is possible to suppress damage to the fish body and reduce power consumption.

[Brief description of drawings]

1 to 3 show a reference example 1, FIG. 1 is a schematic configuration diagram of the apparatus, and FIGS. 2 (a) and 2 (b) are respectively a power supply energization pattern diagram and an oscillating means operation pattern diagram. FIG. 3 shows the relationship between elapsed time and the number of paralyzed fish, FIGS. 4 to 6 show Reference Example 2, and FIGS. 4 (a) and 4 (b) show the energization pattern of the power source and the operation of the oscillation means, respectively. Pattern diagram, fifth
FIG. 6 and FIG. 6 are diagrams showing the relationship between the elapsed time and the number of paralyzed fish and the cumulative number of fish passing through, FIGS. 7 to 10 show an embodiment of the present invention, and FIG. 7 is a block diagram of the control circuit. 8 (a) and 8 (b) are respectively an energization pattern diagram of the power source and an operation pattern diagram of the oscillating means, and FIGS. 9 and 10 are relationship diagrams between the elapsed time and the number of approaching fish and the number of passing fish, respectively. The figure is a perspective view of another application example of the present invention. (1a), (1b) ... electrode array, (2) ... power supply, (3) ...
... electric screen, (4) ... underwater speaker, (5) ...
… Oscillation means.

Front page continuation (72) Inventor Hironari Arai 1-6-14 Edobori, Nishi-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd. (72) Inventor Hiroyuki 1-6-14 Edobori, Nishi-ku, Osaka City, Osaka Hitachi Zosen Corporation In-house (72) Inventor Hiroyuki Suyama 1-6-14 Edobori, Nishi-ku, Osaka-shi, Osaka, Hitachi Shipbuilding Co., Ltd. (72) In Seiji Otani 1-6-14 Edobori, Nishi-ku, Osaka-shi, Hitachi, Ltd.

Claims (1)

[Claims] 1. A plurality of electrode rows arranged in water, a power supply for applying different potentials to the respective electrode rows to form an electric screen between the respective electrode rows, and a power source arranged in proximity to the electric screen. A plurality of underwater speakers, an oscillating means for giving an oscillating signal to each of the speakers so that each of the underwater speakers produces a sound, and a control device for alternately energizing from the power source and operating the oscillating means. A device for blocking the swimming of fish.