JP2017175992A - Method for preventing fish from colliding with wall surface of land rearing tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preventing a fish from colliding with a wall surface of a land rearing tank.SOLUTION: There is provided a method for preventing a fish reared in a cylindrical rearing tank 1 provided on land from colliding with wall surface of the rearing tank 1. A water supply pipe 2 is disposed on an inner wall side of the rearing tank 1, rearing water is discharged from a discharge port 4 of the water supply pipe 2 in a tangential direction of the inner wall surface, and a water flow Fs is formed in the neighborhood of the inner wall surface of the rearing tank 1 so that the fish is prevented from approaching the inner wall surface of the rearing tank 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for preventing a fish from colliding with a wall surface of an aquaculture tank.

  In the breeding of aquatic fish by terrestrial breeding, there are many cases where fish collide with the wall of the breeding tank and drown. In particular, there are many cases where larvae and the like that cannot control swimming drown due to a fracture caused by a collision. This is thought to be due to the startle or abnormal behavior of fish due to external stimuli such as sound and light. In particular, migratory fish such as bluefin tuna are sensitive to external stimuli. For this reason, various ingenuity has been made for breeding without giving unnecessary stress to fish in a land breeding facility.

  For example, in Patent Document 1, focusing on the fact that one of the causes of abnormal behavior such as cannibalism, startle behavior, collision death, etc. occurring in a tuna breeding tank is in visual stimulation, (a) a part of light is transmitted, And using a water tank in which a visual stimulus buffering material reflecting a part of light in an oblique direction is installed on the wall surface and bottom surface of the water tank, (b) placing colored fine particles in the breeding water of the water tank, and (c) the water tank Startling behavior of tuna by raising, storing or transporting tuna by controlling visual stimuli using at least one means of placing light reflectors on wall surface, bottom surface, IKES net surface or obstacle surface Or it describes preventing collision death.

  Patent Document 2 focuses on the startle behavior of tuna and one of the causes of collision death in the light / dark cycle and illuminance, and breeds, stores or transports tuna in an environment where illuminance is maintained at 150 lux or higher. To prevent startling behavior or crash death of tuna.

Japanese Patent No. 4036381 Japanese Patent No. 4081092

In the conventional method described above, the effect lasts only for a certain period of time, and in order to relieve the visual stimulation in the breeding facility, a transparent aquarium, buffer material, equipment for adjusting the illuminance, etc. are required, leading to an increase in cost. There is a problem.
An object of this invention is to provide the method of preventing the collision of the fish with the wall surface of a breeding water tank at low cost.

The present inventors have found that a collision of fish can be prevented by using a breeding water that flows into or circulates in the breeding tank to cause a strong flow in the vicinity of the wall, thereby completing the present invention.
That is, the present invention relates to a method for preventing fish collision in a breeding aquarium provided on land as described below.

(1) A method for preventing fish reared in a cylindrical rearing tank provided on land from colliding with the wall of the rearing tank,
By arranging a water supply pipe on the inner wall side of the breeding aquarium, discharging the breeding water from the outlet of the water supply pipe in the direction of the cut line of the inner wall surface, and forming a water flow near the inner wall surface of the breeding tank, A method for preventing a fish from colliding, characterized by preventing access to the inner wall surface of a breeding aquarium.
(2) The water supply pipe is arranged in the vertical direction on the inner wall side of the breeding water tank, and has a plurality of discharge ports in the length direction of the water supply pipe. How to prevent fish collisions.
(3) The method for preventing collision of fish according to (1) or (2) above, wherein the water supply pipe is connected to a pipe for supplying breeding water with a joint whose base is adjustable in angle.
(4) A method for preventing fish reared in a concrete cylindrical rearing tank provided on land from colliding with the wall of the rearing tank,
By arranging a water supply pipe in the concrete inner wall of the breeding aquarium, discharging the breeding water from the outlet of the water supply pipe in the direction of the tangential line of the inner wall surface, and forming a water flow near the inner wall surface of the breeding tank, A method for preventing a fish from colliding, which is characterized by preventing a fish from approaching the inner wall surface of a breeding aquarium.
(5) The fish collision prevention method according to (4) above, wherein two or more water supply pipes are provided in the height direction of the breeding aquarium.
(6) The fish collision prevention method according to any one of (1) to (5), wherein the water supply pipe is provided with a valve for adjusting the amount of water at the base.
(7) The fish collision prevention method according to any one of (1) to (6), wherein breeding water is supplied to the water supply pipe by an inverter pump for adjusting the amount of water.
(8) The above-mentioned (1) to (1), wherein the place where the water flow is formed is not less than twice the body length (Lmax) of a large fish (2Lmax) from the inner wall surface toward the center of the breeding tank. 7) The fish collision prevention method according to any one of 7).
(9) The collision speed of the fish according to any one of the above (1) to (8), wherein the flow velocity of the water flow is _VLmin or more and 10 _VLmin or less when the swimming speed of a small fish is _VLmin. Method.

  By this invention, the collision of the fish with a breeding aquarium wall surface can be prevented at low cost.

It is a top view which shows the outline of a structure of the breeding apparatus which concerns on embodiment of this invention. It is sectional drawing of the breeding apparatus of FIG. It is a figure which shows the state of the water flow in the breeding apparatus which concerns on embodiment of this invention. It is a figure which shows the relationship between the length of the fish in a breeding aquarium, and a survival rate. It is a figure which shows the structural example of the water supply pipe | tube in embodiment of this invention. It is the schematic which shows an example of the water tank of the breeding apparatus which concerns on embodiment of this invention. It is sectional drawing of the breeding apparatus of FIG.

Fish has a sensory organ that senses water currents and vibrations. It is said that it is because of such sensory organs that the fish swimming in the flock can swim without colliding.
In the present invention, the difference in flow velocity between the inner wall surface and the central part of the breeding aquarium allows the fish to detect changes in the flow, so that the fish does not approach the inner wall surface and the fish collides with the wall surface. To prevent that.
Below, the example of the tuna terrestrial breeding apparatus which concerns on embodiment of this invention is demonstrated in detail using drawing.

(Embodiment 1)
FIG. 1 is a schematic view of an example of an onshore fish breeding apparatus according to Embodiment 1 of the present invention as viewed from above, and FIG. 2 is a cross-sectional view of the onshore breeding apparatus as viewed from the side.
The land breeding apparatus according to the embodiment of the present invention includes a cylindrical breeding aquarium 1, a water supply pipe 2 for supplying breeding water to the breeding aquarium 1, and a drain port 3 for extracting the breeding water from the breeding aquarium 1. ing.

The breeding aquarium 1 is supplied with newly collected inflow water and purified circulating water through a water supply pipe 2. Hereinafter, the inflow water and the circulating water are collectively referred to as breeding water.
In the structure shown in FIG. 1, the water supply pipe 2 is branched to form four water supply pipes 2a, 2b, 2c, and 2d, each of which is arranged in the breeding aquarium 1, and the breeding water is fed to the breeding aquarium 1. Inject into.

  As shown in FIG. 2, the water supply pipe 2 is arranged in the vertical direction near the wall surface of the water tank 1 in parallel to the wall surface. The water supply pipe 2 is provided with a plurality of discharge ports 4 for discharging breeding water. The number, the opening position, and the diameter of the discharge ports 4 in the water supply pipe 2 can be appropriately set by water flow analysis or the like. The total area of the number and the diameter of the discharge ports 4 is preferably equal to or greater than the pipe cross section.

FIG. 5 shows an example of the water supply pipe 2.
FIG. 5A shows an example in which the discharge ports 4 are provided uniformly in the length direction of the water supply pipe 2, and the discharge ports 4 are provided at equal distances between the lengths L <b> 1 of the water supply pipe 2. ing.
Moreover, what was shown in FIG.5 (b) provides many discharge ports 4 between the length L2 corresponding to the depth of the water tank which requires the strong water flow of the water supply pipe 2. As shown in FIG.

When a water flow is generated in the breeding aquarium 1, the breeding water is discharged from the outlet 4 of the water supply pipe 2 along the tangential direction of the inner wall surface of the breeding tank, that is, along the inner wall surface.
Thereby, a strong flow velocity (fast water flow) Fs is generated in the vicinity of the wall surface of the breeding water tank 1.
It is preferable that the installation angle can be freely adjusted at the base of the water supply pipe 2 for discharging the breeding water by providing a union or a flange.

When the water flow Fs is generated, a weak flow velocity (slow water flow) Fw is also generated in the central portion 7 of the breeding water tank (see FIG. 3). In FIG. 1, the size of the arrows indicating the water flows F _S and Fw indicates the speed of the water flow.
When the fish tries to approach the inner wall surface side from the inside of the breeding aquarium 1, the fish senses the difference between the inner flow velocity Fw and the inner wall surface flow velocity Fs. Thereby, since the fish does not approach the inner wall surface side any more, the collision of the fish can be prevented.

FIG. 3 is a diagram showing the relationship between the size of the fish body 5 and the width 6 of the strong water flow formed from the inner wall surface of the breeding aquarium 1 toward the center of the breeding aquarium 1.
As shown in FIG. 3, when the length of the large fish body 5 of the fish bred in the breeding aquarium 1 is “Lmax (cm)”, the strong water flow width 6 is from the inner wall surface of the breeding aquarium. It is preferable to set it to 2 Lmax (cm) or more toward the center.

FIG. 4 is a diagram showing the relationship between the strong water flow width (distance from the wall surface) and the survival rate.
As can be seen from FIG. 4, when the width 6 of the strong water flow is 2Lmax, the survival rate is improved regardless of the type of fish.

Further, when the swimming speed of a small fish among the fish bred in the breeding aquarium 1 is V _Lmin (cm / sec), the flow rate of the breeding water near the inner wall surface of the breeding aquarium is _{VL min} (cm / sec) or more. It is preferable that
Fish generally has a swimming speed of 2 to 4 times the fish length, and the rush speed (V _BS ) is said to be 10 times the fish length.
Therefore, it is preferable that the flow rate of the breeding water can be changed depending on the size of the fish.
Moreover, it is preferable that the maximum value of the flow velocity is not more than the rushing speed, that is, not more than 10 V _Lmin (cm / sec).

The direction of the water flow can be appropriately set according to the water flow analysis result or the like.
1 and 2, the water supply pipe is installed in the vertical direction, but may be arranged at an angle with respect to the vertical direction. It is preferable to set an appropriate angle as appropriate by conducting water flow analysis.
In order to generate the water flow F _S , two or more water supply pipes 2 are provided in the water tank by branching the main water supply pipe. In the case shown in FIG. 1, four water supply pipes are arranged at equal intervals along the inner peripheral surface. It is preferable to determine the number of branches according to the water flow analysis situation and cause a uniform water flow.

It is preferable that the speed of the water flow can be changed according to the growth of the fish in the breeding aquarium 1.
To change the speed of the water flow, change the pump flow rate, or provide a valve on each water pipe that branches the pipe that feeds the breeding water into the breeding water tank 1, so that the amount of water in each water pipe can be adjusted. That's fine. The valve may be manual or an electric valve.
When a flow meter is provided, it is preferable that automation can be performed with a motor-operated valve.
In addition, it is preferable that the water flow can be strongly adjusted with a timer, an operation panel, or the like as necessary when the fish is excited, such as feeding, or the water quality deteriorates.

(Embodiment 2)
FIG. 6 is a schematic view of an example of an onshore fish breeding apparatus according to Embodiment 1 of the present invention as viewed from above, and FIG. 7 is a cross-sectional view of the onshore breeding apparatus as viewed from the side.
In this embodiment, the breeding water tank 1 is made of concrete.
In the present embodiment in which the breeding water tank 1 is made of concrete, the water supply pipe 2 is embedded in the concrete wall 10 as shown in FIGS. By embedding the water supply pipe 2 so that the discharge port 4 of the water supply pipe 2 faces in the direction of the cut line of the inner wall surface of the concrete wall, a swirling flow is generated in the breeding water tank 1.
In this case, it is preferable that two or more water supply pipes 2 are provided in the circumferential direction as shown in FIGS. 6 and 7 and two or more in the vertical direction.
Also in this case, it is preferable to provide a system in which the flow rate can be adjusted by providing a valve outside the tank or changing the flow rate of the pump.

In the present invention, since breeding water is used for generating a water flow, it is only necessary to extend the piping in the conventional equipment, and it is not necessary to increase the equipment other than the conventional system, which is advantageous in terms of cost.
In addition, by causing a flow along the inner wall surface of the breeding aquarium, it is possible to improve the effect of bringing residual food, etc., collected at the bottom of the aquarium to the center, and it is easy to collect them, which is advantageous for water quality management. is there.

DESCRIPTION OF SYMBOLS 1 Breeding tank 2, 2a, 2b, 2c, 2d Water supply pipe 3 Drain outlet 4 Outlet 5 Fish body 6 Water flow width 7 Center part of breeding tank 10 Concrete wall Fs Strong flow velocity (fast water flow)
Fw Weak flow velocity (slow water flow)
Lmax big fish fish length Lmin small fish fish length _{V Lmin} small fish swimming speed _{V BS} fish rush speed _{W B} breeding water of the

Claims (9)

It is a method for preventing fish reared in a cylindrical breeding tank provided on land from colliding with the wall of the breeding tank,
By arranging a water supply pipe on the inner wall side of the breeding aquarium, discharging the breeding water from the outlet of the water supply pipe in the direction of the cut line of the inner wall surface, and forming a water flow near the inner wall surface of the breeding tank, A method for preventing a fish from colliding, characterized by preventing access to the inner wall surface of a breeding aquarium.   2. The method for preventing a fish from colliding according to claim 1, wherein the water supply pipe is disposed in a vertical direction on an inner wall side of the breeding aquarium, and has a plurality of discharge ports in a length direction of the water supply pipe. .   3. The fish collision prevention method according to claim 1, wherein the water supply pipe is connected to a pipe for supplying breeding water with a joint whose base is adjustable in angle. A method for preventing fish reared in a concrete cylindrical aquarium provided on land from colliding with the wall of the aquarium,
By arranging a water supply pipe in the concrete inner wall of the breeding aquarium, discharging the breeding water from the outlet of the water supply pipe in the direction of the tangential line of the inner wall surface, and forming a water flow near the inner wall surface of the breeding tank, A method for preventing a fish from colliding, which is characterized by preventing a fish from approaching the inner wall surface of a breeding aquarium.   5. The method of preventing fish collision according to claim 4, wherein two or more water supply pipes are provided in the height direction of the breeding aquarium.   6. The fish collision prevention method according to claim 1, wherein a valve for adjusting the amount of water is provided at the base of the water supply pipe.   The method according to claim 1, wherein breeding water is supplied to the water supply pipe by an inverter pump for adjusting the amount of water.   The place where the water current is formed is at least twice the body length (Lmax) of a large fish (2Lmax) from the inner wall surface toward the center of the breeding aquarium. The method for preventing collision of fish as described. The flow rate of the water flow is less when the swimming speed of fish was _{V Lmin,} fish method anticollision according to claim 1, characterized in that the following _{V Lmin} than _{10V Lmin.}

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