JP2008173059A - Method and device for preventing sea urchin from moving - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for preventing sea urchin from moving, which has a simple structure and efficiently prevents sea urchin having a prescribed size or more from moving. <P>SOLUTION: The device for preventing sea urchin from moving is structured so as to surround a prescribed area with a movement-preventing means formed by placing a lot of corrosion-resistant hard sticks 7 each having a diameter of about 0.5-3.5 mm in line at an interval of about 7 mm to a length narrower than the height of the shell of sea urchin 12 from and inclining toward the movement-preventing side, and the length of projection is reduced, equivalent to the total of the half of the shell length of the sea urchin, a longest spine projecting sideward about 10 mm, to prevent the sea urchin from moving out of the area at the side where the sticks as the movement-preventing means are inclined, to other areas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sea urchin movement prevention method and apparatus for preventing sea urchins from moving from a predetermined place to the predetermined place or from a predetermined place to the surrounding place on the seabed.

  Sea urchins belonging to echinoderms (European sea urchins, sea urchins, sea urchins, sea urchins, sea urchins, etc.) have a hard shell and a large number of spines and tube feet on the surface. It is movable in the range, and the tube leg is flexible and has a suction cup at its tip, which is used for heeling. These sea urchins use seaweed as a feed, and can be mentioned as the main animal that is said to be involved in the occurrence of so-called “burnt seaweed” that has been seen worldwide in recent years and to sustain it.

  There are various causes of firewood burning, and the occurrence and persistence factors are considered to be different in various places. For example, sea urchins inhabit at an excessive density (for example, the Hokkaido Sea of Japan side It has been pointed out that in the Tohoku region (Pacific side) and around the world (for example, the California coast), excessive feeding pressure due to sea urchins is the main cause of generating and sustaining the sea bream sea area seen in those places.

  In fact, when sea urchins were removed continuously in a seafood-burned sea area in Hokkaido, growth was confirmed in the order of small annual seaweeds, large annual seaweeds, and large perennial seaweeds, and the seaweed bed was restored. It is known that Therefore, it is considered that the development of an efficient means for controlling the sea urchins's range of action and controlling the feeding pressure by the sea urchins is important for the restoration of the seaweed community. And if we can control the excessive feeding pressure by these sea urchins, it will not only be possible to restore the seaweed community, which was difficult until now, but also sea urchins that feed on the seaweed that has been restored and prospered later, Furthermore, it can lead to an increase in the abalone root resource, and in addition to the formation of seaweed communities, it is convenient for a wide variety of fish and shellfish that use it as habitats, hideouts, spawning grounds, and food. As a result, it greatly contributes to the increase in the amount of resources and coastal fishery resources. In addition, the seaweed's carbon-fixing ability and water purification action also help improve global environmental problems such as global warming.

  Against this background, many attempts have been made to develop technologies for limiting the action range of sea urchins or excessive feeding pressure by sea urchins with the aim of restoring seaweed communities. However, sea urchins have very high mobility using spines and tube feet, so it was very difficult to control their range of action and feeding pressure.

  The prior art of this kind of method and apparatus is shown below.

  (1) A net is rounded into a rod shape, and a chain that becomes a heavy stone is attached to the net to be settled so as to surround a seabed or a facility where sea intrusion should be excluded (see Patent Document 1). This uses the property that sea urchins dislike ecologically unstable scaffolds, and is designed to prevent sea urchins from overcoming them by rocking part of the bar net.

  (2) A wall object having an inverted U-shaped groove enclosing air and a device storing an air layer are installed at a position where the walking of sea urchins is to be blocked (see Patent Document 2). This utilizes the property that sea urchins cannot crawl into the air layer.

  (3) Sea urchins cannot pass through the legs and outer walls of facilities where sea urchins should be prevented from entering. In addition, there is a ring-shaped device in which beads are connected in a rotatable manner like a rosary so that the device cannot be climbed over the device (see Patent Document 3).

Japanese Patent Laid-Open No. 10-4808 Japanese Patent Laid-Open No. 62-166826 JP-A-2005-95062

  In the above-described conventional technique, in the one described in Patent Document 1, a gap is formed between the bar net and the sea floor by a chain mooring the bar net to the sea floor, and sea urchins enter from this gap, In addition, when the time after installation elapses, there is a problem that the bar net deteriorates due to the swinging of the waves, or that the organisms adhere to the net and the function of overcoming the rod net is reduced.

  Moreover, in what was described in patent document 2, the air collected in space, such as a reverse U-shaped groove | channel, melt | dissolves in seawater, or it is lost by rocking | fluctuation by a wave etc., The said reverse U-shaped groove | channel There is a problem in that the air inside is likely to be lost, and therefore, it is necessary to regularly supply air to the space of the inverted U-shaped groove to compensate for this, which increases the cost.

  Further, in the case of the one described in Patent Document 3, the rotation movement necessary to prevent the invasion of sea urchins is hindered by the adhering organisms attached to the rotator after the installation of the facility, and the sea urchins over time. There has been a problem that the intrusion prevention function of the kind is lowered.

  The present invention has been made in view of the above, and it is possible to efficiently prevent the movement of sea urchins of a predetermined size or more with a simple configuration, and to eliminate the invasion of sea urchins of a predetermined size or more. It is an object of the present invention to provide a sea urchin migration prevention method and apparatus capable of effectively preventing invasion of seaweed communities or escape of sea urchins from an aquaculture plant.

  In order to achieve the above-mentioned object, the sea urchins movement prevention method according to the present invention is designed to prevent the movement of a hard rod having a corrosion resistance of 0.5 to 3.5 mm in diameter from a gap of about 7 mm. The gap is narrower than the shell height of sea urchins, and is inclined to the side that prevents movement, and even if the protruding length is short, it is the longest that protrudes to the side to half the shell length of the sea urchins. The length of the barbs is added, and approximately 10 mm is added to the length, and a predetermined area is surrounded by a movement blocking means that is erected in a row, and from the area on the inclined side of the bar of the movement blocking means to the other side. The sea urchins were prevented from moving to the side area.

  Further, in this sea urchin movement prevention method, the inclined side of the rod of the movement prevention means is on the outside, and the movement of sea urchins of a predetermined size or more to the seaweed bed provided on the inside is prevented, or The sea urchins larger than a predetermined size were prevented from moving outward from the sea urchin aquaculture farm provided on the inside with the slanted side of the bar inside.

  And the sea urchins movement prevention device for carrying out the above method is a sea urchin shell height to prevent the movement of a hard bar having a corrosion resistance of about 0.5 to 3.5 mm from a gap of about 7 mm. In addition to making the gap narrower, it is inclined to the side that prevents movement, and the length of the longest barb that protrudes to the side is added to one half of the shell length of the sea urchin even if the projection length is short. In addition, a large number of columns are erected in a length of about 10 mm, and a predetermined area is enclosed.

  And in this sea urchin movement prevention device, it was erected on a seaweed reef reef set up with a rod on the seabed or a sea urchin aquaculture farm.

  Moreover, the sea urchins movement prevention device is provided with a hard rod having a corrosion resistance of about 0.5 to 3.5 mm in diameter on the upper surface or side surface of the base, and the sea urchins whose movement is about 7 mm. The longest barb that is narrower than the shell height, tilts to the side that prevents sea urchins from moving, and protrudes to the side of the shell length of the sea urchins, even if the protruding length is short. And a length obtained by adding approximately 10 mm to the length, and a plurality of movement prevention devices standing in a row so as to surround a predetermined area. And the said movement prevention instrument was comprised with the some strip | belt-shaped movement prevention instrument.

  According to the present invention, the movement of sea urchins of a predetermined size or more can be prevented with a simple configuration, and the invasion of sea urchin communities to which the invasion of sea urchins of a predetermined size or more should be excluded, or sea urchins It is possible to effectively prevent escape from the aquaculture farm.

  Sea urchins trying to invade a predetermined area of the seabed, such as a concrete block that creates a seaweed community that should prevent sea urchins from entering, reach a place where thin and hard bars are aligned, You can touch the rod, but the aligned rod is inclined to the side where you want to prevent intrusion, and it is an elevation angle for sea urchins trying to invade, so get over the tip of the aligned rod You can't go to the other side (place or part of the seaweed community).

  This is because sea urchins are moved by (1) changing and holding the posture (angle) of the body by changing the angle of the spine, and (2) extending the tube leg in the direction of travel, and grabbing the object with the suction cup at the tip This is because it is achieved by a method of pulling the body in the direction of travel by atrophying the tube leg as it is.

  In addition, sea urchins can grasp a thin stick with a tube leg, and when passing through a narrow gap, by manipulating the angle of the body so that the width of the body becomes the smallest, and by lying this tube leg sideways, Although it is possible to go through dexterously so as to cut in a narrow gap, as in the present invention, the width of the body of the sea urchins of a predetermined size is between the aligned bars with only a gap below the shell height being the smallest, Sea urchins larger than this predetermined size cannot pass through.

  In addition, to get over the aligned rods to go beyond the aligned rods, even if the surface on the other side of the rods is gripped by a suction cup at the tip of the tube foot and the tube foot is contracted, the rod will still have a diameter. Because it is thin enough to be 0.5-3.5mm, the tube foot does not get caught at the tip of the rod, and it will be in a state of gripping the other side of the rod through the aligned rods, The sea urchins cannot get over the rods that are aligned in the gap where the sea urchins cannot pass through. In addition, as described above, since the rod 7 is sufficiently thin, the fact that the tip end surface of the rod 7 cannot be grasped by the tube foot is one of the reasons why the sea urchins cannot get over the movement preventing device. Thus, in the sea urchin movement prevention method and apparatus according to the present invention, the movement of sea urchins having a predetermined size or more to a predetermined area can be prevented.

  It is a well-known fact that sea urchins have the property of avoiding strong currents, as can be seen from the fact that when the wave current becomes stronger than a certain level, feeding activity is restricted. When sea urchins try to cross the device of the present invention, they have to get over the aligned bar parts, but the contact area between the sea urchins and the bar part is much less than when they are on a flat surface. Less. As a result, sea urchins will not be able to adhere to the object with their tube legs, so sea urchins who dislike ecologically unstable scaffolds are not expected to try to overcome the device of the present invention when the flow is strong. Is done. As described above, the effect of preventing sea urchin movement by the apparatus of the present invention can function strongly by different processes when the flow is strong.

  As described above, the method and the apparatus of the present invention can prevent intrusion into a facility such as a concrete block for forming seaweed communities of sea urchins having a predetermined size or larger, or a predetermined area of the seabed.

  As a result, by using the sea urchin migration prevention method and apparatus according to the present invention, it is possible to create seaweed communities in sea-burned sea areas that are sustained by sea urchins as seen in various parts of the world including Japan. can do. In addition, through the realization of seaweed communities, the increase of sea urchins and abalone root resources, as well as coastal fishery resources such as the increase of seafood communities, habitats, hideouts, spawning grounds, and a wide variety of seafood resources It contributes to the prevention of global warming through the carbon fixation ability of seaweed communities and the improvement of global environmental problems through water purification. Further, not only seaweed communities can be created, but also the migration of sea urchins of a predetermined size or more from a predetermined area arranged to surround the apparatus of the present invention can be prevented, and the increase of sea urchins of a predetermined size or more can be prevented. A farm can be formed.

  The sea urchins movement prevention method according to the present invention encloses a predetermined area with a movement prevention means that prevents the sea urchins of a predetermined size from passing through or getting over, and within the predetermined area. Is used as an algae breeding ground, it prevents the invasion of sea urchins of a size that is harmful to the area, that is, larger than a predetermined size that causes damage to seaweeds. When this area is used as a sea urchin aquaculture site, sea urchins that have grown beyond a predetermined size in this area are prevented from escaping to the outside.

  As an example of the movement preventing means surrounding the predetermined area, for sea urchins trying to intrude a thin and hard rod at a space where a predetermined size of sea urchins cannot pass through a base such as a concrete block. There is a movement blocking device that is erected in a row so as to be at an elevation angle, that is, inclined to the blocking side.

  Hereinafter, an embodiment in which the predetermined area is a seaweed bed will be described with reference to the drawings.

  FIG. 1 shows an algae basin 2 formed on the upper surface of the algae basin reef 1 set on the seabed, and the algae basin 2 has a substrate plate 3 on which algae eggs and young gametophytes have been previously established in an agitation site. The seaweed 4 is grown using the substrate plate 3 as a nucleus.

  At this time, the growing seaweed 4 cultivated in the seaweed bed 2 is a prey for sea urchins, and even if grown to a certain size, it is still eaten by sea urchins and is said to be a seaweed breeding. The initial goal cannot be achieved.

  Therefore, the seaweed bed 2 is surrounded by a movement prevention device 5 that is capable of preventing the movement of sea urchins that are desired to prevent entry into the seaweed bed 2, that is, sea urchins having a predetermined size or larger. The sea urchins at this time mainly assume Ezobafun sea urchin and Kitamura sea urchin.

  FIGS. 2 to 6 show an example of the movement preventing device 5. When the planar shape of the movement preventing device 5 is a ring shape as shown in FIG. 1, for example, it is formed on the upper surface of the base body 6 formed in a ring shape. The thin and hard rod 7 is configured to stand in a row with a gap through which sea urchins of a predetermined size or more cannot pass. Each rod 7 is inclined in the direction of preventing sea urchins from entering, that is, toward the outside with respect to the seaweed bed 2, and is at an elevation angle with respect to the sea urchins intrusion side. At this time, if the angle of the bar 7 is perpendicular to the intrusion side, the sea urchins may get over.

  The gap through which the sea urchins of the rod 7 cannot pass is a gap that is at least narrower than the shell height of the sea urchin having a size that is desired to prevent entry (movement). However, if the gap between the rods is too narrow, it becomes a plane with many rods 7 and sea urchins can climb this plane using pipe feet. Would allow intrusion.

  For these reasons, when the shell height of sea urchins to be prevented from entering (moving) is about 15 mm, the gap between the rods 7 is preferably about 14 mm. This gap is parallel to the entire length of the rod 7 if the rod 7 is parallel, but when the rod 7 is inclined and is erected on a curved base, the rod 7 is radial. However, the above-mentioned preferable gap means the maximum gap on the tip side.

  On the other hand, the standing angle (elevation angle) α of the rod 7 is preferably in the range of approximately 30 degrees to 60 degrees from the horizontal to the upward when facing upward, and is 45 degrees or more from the horizontal when facing downward. It is desirable. Even when the rod 7 is directed downward, the rod 7 for sea urchins located below the rod 7 is overhanged and has an elevation angle.

  The rod 7 can be erected on the upper surface of the substrate 6 as shown in FIG. 3 or on the side surface of the substrate 6 as shown in FIG. And when standing on the upper surface of the base body 6, it stands up at an angle over a range from horizontal to an angle not including 90 degrees. Further, when standing on the side surface of the base 6, it can stand up from an angle close to 90 degrees upward to an angle exceeding 45 degrees downward. If the downward angle exceeds approximately 50 degrees, the space between the side surface of the substrate 6 and the rod 7 is not preferable, so the downward angle of the rod 7 is set to 50 to 90 degrees. As shown in FIG. 6, the bar 7 is provided with a horizontal portion 7a and can be set at an arbitrary angle up to 90 degrees from the tip of the horizontal portion 7a downward.

  The rod 7 that is erected in alignment with the base 6 needs to be a hard material that does not deform due to the force of waves or sea urchins. If the diameter of the rod 7 is too large, when the rod 7 in which sea urchins are aligned is grasped from the outside of the seaweed bed 2 by the tube foot, the tube foot is caught on the tip of the rod 7 and the tube foot is contracted. 7 may get over the tip of 7 and enter inside. For this reason, the rod should not be too thick, and its diameter is preferably about 0.5 to 3.5 mm. In addition, the material is preferably stainless steel because of its good corrosion resistance in the sea. In spite of stainless steel, corrosion occurs due to the influence of chloride ions. Therefore, it is not preferable to use it as it is for a long period of time, and it is desirable to make it as thick as possible and to perform corrosion resistance processing by galvanization or the like.

  The rod 7 may not be too short or too long. For example, when the length of the rod 7 that is standing upright is as short as 10 mm, most sea urchins lift the body in the direction of travel by manipulating the spines and tilting their body in the direction opposite to the direction of travel. It is possible to easily get over the aligned rods 7. On the other hand, when the lengths of the aligned rods 7 are too long, the standing rods 7 can prevent the sea urchins from entering the sea urchins. Increase. Therefore, the length of this rod should be set to the minimum length that sea urchins cannot get over even if they tilt their bodies. Preferably, the length of the rod 7 standing in line is one half of the shell length of the sea urchin to be prevented from entering, and the length of the longest spine attached to the side of the sea urchin. It is good to set it to the length which added about 10 mm further about the length which added the length.

  For example, in the case of sea urchins with a shell length of 40 mm, even if the length of this rod is short, add about 20 mm of the longest spine protruding to the side to 20 mm, which is a half of the shell length, and further shorten it. It is desirable to set about 50 mm including 10 mm.

  Furthermore, if the stainless steel rod used for the rod 7 is placed in seawater for a long time, the surface of it will grow, such as innocuous coral algae, small and thin red algae (eg, Igis), and fine ciliates. However, it is unlikely that they will grow large enough to affect the function of the present invention on a fine stainless steel rod, and the use of a stainless steel rod for the rod 7 is most effective when maintaining long-term functionality. It is considered preferable.

  In addition, it is preferable that the movement prevention instrument 5 of the said structure is comprised from stainless steel as a whole. When the base 5 and the rod 7 are integrated, it is convenient from the viewpoint of strength and when taking anticorrosion means from seawater. However, only the rod portion is made of metal, and the base portion connecting the rod portion may be made of another material, for example, a rubber material such as natural rubber other than the above-described concrete. In the case of natural rubber, there is almost no deposit as with stainless steel.

  In addition, the material of the rod 7 may be other materials other than stainless steel, such as other alloys and plastics, as long as they fulfill the above-described functions.

  In the embodiment shown in FIG. 1, an example in which the upper surface of the seaweed formation reef 1 is largely surrounded by the movement prevention device 5 has been shown. However, as shown in FIG. A plurality of locations on the upper surface of the reef 1 may be surrounded.

  The movement prevention device 5 may be integrated as shown in FIG. 1, but a partial movement of the belt-like movement prevention device 5a as shown in FIG. It is good also as the movement prevention instrument 5 of the predetermined surrounding shape as shown, for example in FIG. 1 by connecting with a connection means.

  FIG. 9 shows an example in which a certain area of the sea bottom where a plurality of seaweed reefs 1 are installed is largely surrounded. In this case, a plurality of strip-like movement prevention devices 5a shown in FIG. The movement prevention device 5 is made.

  In addition, when the seabed is surrounded by the movement prevention device 5 in this way, when the seabed is undulated, the base 6 does not follow this undulation when the base is rigid. A weight is attached, and a movement prevention device 5 having a large number of rods 7 erected on the base 6 is attached to the upper end edge of the net 10 which is vertically suspended with a float 9 attached to the upper end, so as to surround a predetermined area of the seabed. Also good. The size of the ring constituting the chain 8 used for the weight is such that the sea urchins of a predetermined size cannot pass through.

  Furthermore, you may make it provide the said movement prevention instrument 5 double and triple with respect to a predetermined area.

  FIG. 11 to FIG. 13 show another embodiment of the movement preventing means, which has a predetermined size around a predetermined area, a member constituting the area, for example, the seaweed reef reef 1. It has a structure in which a large number of rods 7 having a length are directly erected in a gap for preventing the sea urchins from moving. FIG. 11 shows an example in which rods 7 are erected on the top plate of the seaweed reef 1, FIG. 12 is a side surface thereof, and FIG. 13 is an example in which rods 7 are erected around each leg 1 a.

  FIG. 14 is an example in which the port is made of a seaweed bed by installing a movement prevention device 5 configured in a band shape so as to be closed at the opening of the quay 11 in the port made of U-shaped concrete. In this case, the inner side and the outer side of the quay 11 are partitioned by the movement prevention device 5 in which the rod 7 is inclined outward. However, in the side wall portion P of the quay where both ends of the movement prevention device 5 are opposed, However, by climbing up and down along the inner surface of this part of the quay, the movement prevention device 5 is overcome, so that other movement prevention means are provided on the wall surfaces 11a and 11b of the portion P where both ends of the movement prevention device 5 face each other. Install vertically with one end protruding onto the water. As the movement blocking means attached to the wall surfaces 11a and 11b in this case, a movement blocking device 5 in which the rod 7 is inclined outward as shown in FIGS. 14 and 15 may be used, or the rod 7 may be directly attached to the wall surface 11a, 11b may be provided so as to be inclined outward.

  In each of the above-described embodiments, sea urchins are prevented from entering the seaweed bed 2 set inside the movement preventing means from the outside. However, as shown in FIG. An embodiment in which the inside of the movement prevention device 5 is used as an aquaculture site 13 for sea urchins 12, and the movement prevention device 5 prevents the sea urchins 12 having a predetermined size or more from escaping from the inside of this increase culture site 13. There is also. In this case, the rod 7 of the movement prevention device 5 is inclined inward.

  In this embodiment, sea urchins smaller than the gap between the rods 7 of the movement prevention device 5 pass through the movement prevention device 5, and therefore sea urchins of a size that cannot pass through the movement prevention device 5 in the aquaculture farm 13. Only can be selectively aquacultured.

  In addition, in the movement prevention device 5 for preventing the movement of sea urchins from the inside to the outside, the rod 7 that is erected and inclined to the inside of the base 6 is provided on the base 6 as shown in FIG. Although it may be erected on the upper surface, it may be erected on the inner surface thereof.

  In each of the above-described embodiments, the gap between the rods 7 of the movement prevention device 5 is a gap in which sea urchins of a predetermined size or more cannot pass through. It is possible to freely go in and out through the rod 7 of the movement prevention device 5, for example, enter the algae ground inside the movement prevention device 5 and eat the seaweed in the algae ground, but these small sea urchins are not so much It will not be a problem because it will not cause major damage. For example, sea urchins with a shell length of about 13 mm or less are unlikely to cause significant food damage. Therefore, even if sea urchins with a shell length not exceeding 13 mm are allowed to enter the algae, there is no problem. Absent. Since the shell height of the sea urchin having a shell length of about 13 mm is about 8 mm, the gap for preventing the sea urchins having a shell length of 13 mm or more from passing through is about 7 mm or more.

(Test Example 1)
(1) Test method The test apparatus A shown in FIGS. 17 (a) and 17 (b) is placed in a water tank in which seawater is poured up to a depth of 30cm in a water tank of length, width and depth of 230, 93, 80cm. And the comparison apparatus B shown to Fig.18 (a), (b) was installed. Then, 50 individual Murasaki sea urchins having a shell length of 31.2 to 62.8 mm were placed in this water tank, and a comparative test was performed under conditions of a water temperature of 13 to 18 ° C. At this time, makombu leaf pieces a and b having a size of 40 × 40 mm were placed as bait for guiding sea urchins at the central portions of the apexes of the cylinders 14 and 14 of both apparatuses A and B.

  The test apparatus A has a stainless steel rod 15 having a thickness of 1.6 mm arranged in a row so as to go around the cylinder 14 from the lower surface of the cylinder 14 made of natural rubber having a diameter of 90 mm and a height of 120 mm to a side surface 110 mm high. Forty-eight were aligned and erected. Since the stainless steel bars 15 are erected radially on the side surface of the cylinder 14, the gap between the bars is narrow near the cylinder 14 and wide at the tip. The protruding length of the upright stainless steel rod 15 is 60 mm, and is arranged toward the upper 45 degrees. The gap at the tip of the stainless bar 15 at this time was 11.4 mm, which is a gap slightly narrower than the shell height of the smallest sea urchin in the water tank.

  On the other hand, the comparison device B used the same cylinder 14 used in the test device A, and no rod was attached thereto.

  Visual observation was performed once or more once a day, and it was investigated for both devices A and B whether the sea urchin could reach the macaque leaf pieces a and b and whether they had eaten it. Macacom leaf pieces a and b were replaced every 2 days with new ones, and this aquarium experiment was continued for 2 weeks.

(2) Test results Soon after the start of the test, the sea urchin began to climb each column 14 of the test apparatus A and the comparison apparatus B. In the comparison apparatus B, the sea urchin immediately reached the macombe leaf piece b placed at the apex of the cylinder 14 and started eating. One after another, sea urchins gathered on the leaf b were observed.

  On the other hand, in the test apparatus A, the sea urchin could not get over the stainless steel rod 15 attached to the cylinder 14 and continued to go around the underside of the aligned stainless steel rod 15 as if looking for the climbing port. On day 2 of the observation day, all the macaque leaf pieces b on the comparison device B were eaten up. On the other hand, no eating trace was observed on the macacom leaf piece a on the test apparatus A, and no sea urchin reaching this was observed. It was observed that the sea urchin still remained under the aligned stainless steel rods 15. During the subsequent two-week test period, the appearance of eating macaque leaf pieces a on the test apparatus A and the appearance of sea urchins over the stainless rod 15 were not observed at all.

(3) Findings Based on the results of the above test, a device in which a large number of thin and hard rods that cannot be passed over are aligned with gaps that cannot pass through the sea urchins. It was shown that it is extremely useful for preventing sea urchins from creeping up by being attached to the outer surface (or upper surface) of a facility such as a concrete block that forms seaweeds that should be prevented. Moreover, it was shown that the method of preventing sea urchin invasion by the above-mentioned instrument is extremely useful for preventing sea urchin invasion. When the device of the present invention is actually used in the sea, it should naturally be used with a size suitable for the place and case.

(Test Example 2)
(2) Test method The test apparatus A shown in FIGS. 17 (a) and 17 (b) was placed in a tank under running water in which seawater with a depth of 30 cm was placed in a tank with a length, width and depth of 230, 93, and 80 cm. Was installed. Whether or not three sea urchins with a shell length of 35, 45, and 55 mm are placed on the central portion of the apex surrounded by the stainless steel bar 15 of the test apparatus A, and whether or not the sea urchin can go out from the inside of the test apparatus A. Observed about. The water temperature was tested at 16 ° C.

(2) Test result After 20 minutes from the start of the test, an individual was observed that the sea urchin got over the rod part of the test apparatus and went outside. After 24 hours from the start of the test, all the individuals did not stay on the test apparatus A.

(3) Findings In Test Example 1 from the results of the above test, sea urchins of the same size appear from the inside to the outside of the row of bars of the testing apparatus A in the testing apparatus A that could prevent sea urchins from entering from the outside. It was shown that it can. This is due to the fact that the bar 7 of the test apparatus A is inclined 45 degrees outward, and that the vertical angle of the bar row is a depression for the sea urchin inside the bar row.

It is a perspective view which shows the example which used the movement prevention instrument for the seaweed formation rock. It is a perspective view which shows a movement prevention instrument partially. It is sectional drawing of a movement prevention instrument. It is a partial front view of a movement prevention instrument. It is explanatory drawing which shows the example which erected the stick on the side surface of the base | substrate. It is explanatory drawing which shows the example which erected the stick on the side surface of the base | substrate. It is a perspective view which shows the example which installed multiple small movement prevention apparatuses in the seaweed formation reef. It is a perspective view which shows the movement prevention instrument divided | segmented into the strip | belt shape. It is a perspective view which shows a mode that the several seaweed formation reef was enclosed with the movement prevention instrument. It is a partial front view which shows the other example of a movement prevention instrument. It is a perspective view which shows the example which installed the stick | rod used as a movement prevention means on the upper surface of a seaweed formation reef. It is a perspective view which shows the example which erected the stick | rod used as a movement prevention means on the side surface of a seaweed formation reef. It is a perspective view which shows the example which erected the stick | rod used as a movement prevention means in the leg part of a seaweed formation reef. It is a top view which shows the usage example from which a movement prevention instrument differs. It is an expansion perspective view which shows the P section of FIG. It is a perspective view which shows the example which used the movement prevention instrument for the sea urchin aquaculture farm. The test apparatus is shown, (a) is a front view and (b) is a side view. The comparison apparatus is shown, in which (a) is a front view and (b) is a side view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Algae field reef, 1a ... Leg part, 2 ... Algae field, 3 ... Substrate plate, 4 ... Seaweed, 5 ... Movement prevention device, 5a ... Strip movement prevention device, 6 ... Base | substrate, 7 ... Rod, 7a ... Rod 8 ... Chain, 9 ... Float, 10 ... Net, 11 ... Quay, 11a, 11b ... Wall surface, 12 ... Sea urchins, 13 ... Aquaculture, 14 ... Cylinder, 15 ... Stainless steel rod, A ... Test device , B: comparison device.

Claims (6)

Inclination of hard rods with a diameter of 0.5 to 3.5 mm that is less than the shell height of sea urchins whose size is desired to be prevented from moving from about 7 mm to the side where the movement is prevented. Furthermore, even if the projecting length is short, the length of the longest barb that protrudes to the side is added to one half of the shell length of the sea urchins. Enclose a predetermined area with the standing movement prevention means,
A sea urchins movement prevention method characterized in that the sea urchins are prevented from moving from an inclined area of the rod of the movement preventing means to an area on the other side.   The slanted side of the rod of the movement prevention means should be on the outside to prevent the migration of sea urchins of a size larger than a predetermined size to the seaweed bed provided inside, or the slanted side of the rod should be on the inside 2. The sea urchin movement prevention method according to claim 1, wherein sea urchins having a predetermined size or larger are prevented from moving outward from the sea urchin aquaculture site. The hard rods having a corrosion resistance of 0.5 to 3.5 mm in diameter are made narrower than the shell height of sea urchins whose movement is to be prevented from about 7 mm, and inclined to the side to prevent movement, Even if the projecting length is short, add the length of the longest barb that protrudes to the side to one half of the shell length of the sea urchins, and add a length of about 10 mm to it. This is a sea urchin movement prevention device characterized by surrounding a predetermined area.   4. The sea urchin migration prevention device according to claim 3, wherein the sea urchin seafloor reef set up on a seabed or a sea urchin aquaculture site is installed. A hard bar having a corrosion resistance of about 0.5 to 3.5 mm in diameter on the upper surface or side surface of the substrate is made to have a gap narrower than the shell height of sea urchins whose movement is to be prevented from moving from about 7 mm. In addition to adding the length of the longest barb that protrudes to the side to one half of the shell length of the sea urchins, and adding about 10 mm to it. A sea urchins movement prevention device characterized in that a predetermined area is surrounded by a movement prevention device which is arranged in a row in length.   6. The sea urchins movement blocking apparatus according to claim 5, wherein the movement blocking apparatus comprises a plurality of belt-shaped movement blocking apparatuses.

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