JP2012223128A - Structure for coral growth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for coral growth that ensures that coral larvae implanted on a grid-like structure can be raised without being eaten or dead.SOLUTION: The structure 1 for coral growth includes a grid-like structure having the form of a net on a planar view, in which rectangular, open squares 3 are formed horizontally and vertically by combining muntins and cross rails within a rectangular frame 2, both the muntins and the cross rails having the same width as the frame 2. The structure 1 is installed at the bottom of the sea using poles 5 mounted at the four corners of the structure 1, in such a way that the structure is away from the bottom of the sea. The structure resists harmful organisms such as Acanthaster, Echinoidea, shellfish from attaching to it, thereby avoiding these harmful organisms from eating corals or scraping corals off from the grid-like structure, while also avoiding such problems as corals being killed as the structure is covered with sand, seaweed, colonial ascidians, bryozoans, etc.

Description

  The present invention relates to a net-like structure having a certain thickness in the vertical direction by dividing a rectangular, other polygonal frame, or a circular or elliptical frame into a horizontal beam and a vertical beam, and a honeycomb-shaped beam. Constructed, honeycomb-like structures with a certain thickness in the vertical direction, circular, elliptical, or polygonal similar beams arranged concentrically, and each beam is connected radially by another linear beam It consists of a structure having a certain thickness in the vertical direction (hereinafter, these are representatively referred to as a grid structure. Therefore, the grid structure referred to in the present invention includes each of the above structures), and coral. The present invention relates to a method for installing a coral-growing structure used for landing and growing larvae on the seabed, and a coral-growing structure used in the method.

  Coral reefs contribute to environmental conservation in coastal waters and play an important role in the conservation and development of marine resources. However, coral reefs are damaged by coastal landfills, seawater contamination, large-scale food damage caused by sea urchins, and bleaching, and their restoration Is an urgent need. Various attempts have been made to create coral reefs from the viewpoint of coral reef protection. One of them consists of a single lattice structure or a structure in which a plurality of structures are three-dimensionally assembled, and it has been proposed that this structure be installed on the sea floor to allow coral larvae to land and grow. (Patent Document 1).

JP 2009-77649 A

  It is said that coral larvae swim using cilia, land on the adherent base, transform into a polyp, and gradually grow to increase the polyp. According to the report, coral larvae tend to land in dark places rather than in direct sunlight, and it is said that places with currents are easier to land.

  Coral breeding structures composed of the aforementioned grid-like structures can be installed just by submerging them from the work boat as they are, and coral larvae floating on the flow of tide can pass through the structure. In addition, coral larvae that have entered the open squares, such as rectangles, hexagons, arcs, or trapezoids, formed by structural bars are not easily dissipated by the surrounding bars, and this structure is converted into a net-like structure. In comparison, the coral larvae have a large floor area, and are more likely to be shaded by being blocked by a pier. Therefore, even if the seabed is a place where there is no coral breeding base such as sand or coral gravel, Coral larvae can be easily settled even in places where coral larvae have not grown even if they have moved due to the flow of tide and the coral larvae have landed, and the coral cultivation structure Is for example easily have such advantages can be integrally molded by a fiber reinforced plastic FRP, there is still room for improvement.

  One of them is coral larvae and polyps that have landed on the coral cultivating structure are preyed by sea urchin starfish, sand shrimp, etc., scraped off from the coral cultivating structure by sea urchins or snails, This is a measure against being killed by being covered with seaweed, colony or bryozoans.

  The present invention has been made in view of the above points, and a coral cultivating structure installation method that allows coral larvae landing on a lattice structure to be reliably grown without being preyed or killed, and It aims at providing the structure for coral cultivation used by this method.

  The invention according to claim 1 is characterized in that a coral growing structure made of a lattice structure is supported by a pole so as not to come into contact with the seabed, and is installed away from the seabed.

The invention according to claim 2 is a coral-growing structure used in the invention according to claim 1, which is composed of a lattice-like structure, attached to the lattice-like structure, and attached to the pole that supports the lattice-like structure. Is characterized in that an umbrella or umbrella-bone-shaped intrusion prevention device is installed between the sea floor and the lattice structure to prevent the pests such as sea starfish, sea urchins and shellfish that are harmful to the growth of coral larvae. ,
According to a third aspect of the present invention, the ingress prevention device according to the second aspect of the present invention is loosely fitted to the pole, and a sleeve that supports the ingress prevention device and a circumferentially divided portion are assembled around the pole. And a collet that is pushed into the sleeve in a state where the sleeve is pressed, and at least one of the inner periphery of the sleeve and the outer periphery of the collet is tapered in the vertical direction.

  The invention according to claim 4 is the invention according to claim 2 or 3, wherein the pole protrudes up and down through the lattice structure, and the portion protruding upward from the lattice structure has the lattice structure. A light-shielding member that blocks sunlight is detachably attached.

  According to the invention according to claim 1, since the coral cultivating structure made of a lattice structure is installed away from the seabed, pests such as sea starfish, sea urchins and shellfish are difficult to be attached, and therefore predation by these pests. Scraping from the grid structure and the lattice structure is less likely to occur, and the problem of being covered and destroyed by sand, seaweed, colony, bryozoans, etc. is less likely to occur. The survival rate of coral larvae and polybes will be improved and they will be able to be cultivated reliably.

  According to the invention according to claim 2, the invasion prevention device attached to the pole can prevent the above-mentioned pests from climbing the pole and entering the coral cultivation structure. It can be done reliably.

  According to the third aspect of the present invention, when the collet is assembled around the pole and pushed into the sleeve, the ingress prevention tool can be easily fixed to the pole by the wedge action due to the taper.

  Coral whitening is performed by a rise in seawater temperature and strong sunlight in summer. However, as in the invention according to claim 4, if a light-shielding member that shields sunlight is attached to the pole as required, whitening can be reduced. . Further, the light shielding member is attached using a pole that supports the lattice structure of the coral growing structure, and the support structure of the light shielding member can be simplified.

The perspective view of the structure for coral cultivation installed away from the seabed. The perspective view of the structure for coral cultivation which attached the lattice board. The perspective view of the structure for coral cultivation which attached the entrance prevention tool and the shielding board to the pole. The perspective view of another example of the structure for coral cultivation which similarly attached the entrance prevention tool and the shielding board to the pole. Sectional drawing of the approach prevention tool fixed to the pole by the chuck means. Sectional drawing of the principal part of the entry prevention tool fixed to the pole using the chuck | zipper means shown in FIG. The perspective view of another example of a chuck means. The perspective view of another example of the structure for coral cultivation installed away from the seabed. Sectional drawing of the principal part of the structure for coral cultivation which fixed to the pole using the spacer at fixed intervals. The perspective view of a spacer. The perspective view of another example of a spacer. Sectional drawing which connected the structure for upper and lower coral cultivation using the spacer shown in FIG. The perspective view of the structure for coral cultivation arranged in parallel with the horizontal direction. The perspective view which shows another parallel example. The perspective view which attached the light-shielding board to the structure for coral cultivation shown in FIG.

Hereinafter, coral cultivation structures according to embodiments of the present invention will be described with reference to the drawings.
The coral cultivating structure 1 shown in FIG. 1 has a net-like shape in a plan view in which a rectangular frame 2 is formed in a rectangular frame 2 by combining vertical bars and horizontal bars having the same plate width as the frame 2 to form rectangular openings 3 in the vertical and horizontal directions. It is made of a lattice-like structure and may be made of metal, natural resin or synthetic resin, but is preferably integrally formed of fiber reinforced plastic FRP. In this case, it is desirable to form a draft as shown in FIG. 2, FIG. 6, FIG. 9 and FIG.

  It is desirable that the mesh 3 has a vertical depth greater than a horizontal length perpendicular to the vertical direction. By reducing the area of the opening and increasing the depth, it is possible to reduce the damage caused by small fish on the back side. In fact, the inventors of the present invention have grown corals under the same conditions by separating the two types of coral-growing structures 1 having the same depth and a large and small lateral length from the seabed. It was confirmed that the small one had less damage from small fish than the big one.

  In order to make the opening of the mesh 3 small, as shown in FIG. 2, a lattice plate 4 having an opening 4 a smaller in size than the mesh 3 may be attached on the coral cultivation structure 1. The grid plate 4 is preferably manufactured by integral molding with the coral cultivating structure 1, although the mold is complicated in production. The lattice plate 4 may be attached to the lower surface as well as the upper surface of the coral growing structure 1.

  Further, the coral-growing structure 1 has shaft-like poles 5 of the same length protruding at the four corners and attached to the top and bottom by the same length. Although this pole 5 is not shown in the figure, it is preferably tapered so that the tip (lower) end can be easily pierced into the seabed. When the coral-growing structure 1 is installed on the seabed, each pole is shown as shown in the figure. The coral cultivating structure 1 is fixed away from the seabed by inserting the tip of 5 into the seabed.

  The poles 5 of the present embodiment are attached to the four corners of the coral cultivation structure 1, but only one may be attached to the center, or a plurality other than four, for example, five in the center and four corners. It may be attached. The poles 5 include the four corners of the coral cultivation structure 1, and it is desirable to attach four or more poles because the attachment state is stable.

  FIG. 3 shows a cormorant cultivating structure 1 shown in FIG. 1 supported at the four corners, and a portion of each pole 5 projecting up and down from the structure 1 under the coral cultivating structure 1 damages the growth of coral larvae. Attach an intrusion prevention device 7 that prevents the pests such as sea urchins and shellfish from climbing up the pole 5, and radiate the sun to the coral breeding structure 1 on the pole portion protruding above the structure 1. A light shielding plate 8 which is a light shielding member to be shielded is attached. FIG. 4 shows a coral cultivation with an intrusion prevention tool 7 under the coral cultivation structure 1 of a pole 5 attached to the center of the coral cultivation structure 1. The intrusion prevention device 7 and the light shielding plate 8 will be described in order below.

  The ingress prevention tool 7 is loosely fitted to the pole 5 and is fixed by a chuck means described later (the sleeve 11 shown in FIG. 3 has a rectangular ring shape, but may have a circular ring shape. It is also possible to form an umbrella frame by attaching a resin sheet to the entry preventing device 7.

  The chuck means is divided into a plurality of parts in the circumferential direction, preferably divided into two as shown in FIG. 5, and has a collet 13 that holds the pole 5 from both sides, and the collet 13 has a tapered shape whose outer surface is constricted upward. The inner surface is uneven with respect to the pole 5, and preferably has a sawtooth shape that bites downward. On the other hand, the sleeve 11 is formed so that the inner surface expands downward.

  FIG. 7 shows another aspect of the collet, in which a pair of thick collets 14 is formed with a lateral groove at the center in the vertical direction of the tapered outer surface, and a rubber band 15 is attached to the lateral groove to form a pole. A pair of collets 14 sandwiching 5 is connected and attached to the pole 5.

When fixing the ingress prevention device 7 to the pole 5 to which the coral growing structure 1 is attached, the sleeve 11 of the ingress prevention device 7 is first inserted into the pole 5 from below, and then the split collet 13 shown in FIG. After putting the pole 5 together, the sleeve 11 is shifted downward and pushed into the collet 13 from above (FIG. 6). The collet 13 sandwiching the pole 5 may be pushed up and pushed into the sleeve 11 from below.

  At the time of pushing, the collet 13 is crimped and fixed to the pole 5 by the wedge action by the taper of the sleeve inner periphery and the collet outer periphery, and the ingress prevention tool 7 is also fixed to the pole 5 accordingly. The push-in is performed manually, but it can be lightly pushed and temporarily fixed. Thereafter, the ingress prevention tool 7 can be lowered by its own weight and fixed to the pole 5 by the wedge action described above.

  The light shielding plate 8 is made of metal, preferably hard resin, and is attached by being pushed in from the upper end of the pole 5 so as to cover the coral cultivation structure 1 with a certain interval and shield the sunlight from the coral cultivation structure 1. It is formed in a size that can be. The shading plate 8 shown in the figure is attached with a slight incline toward the south in order to block sunlight from direct sunlight in summer. In addition to the action of blocking the sunlight, the light shielding plate 8 forms a shade to make it easy to deposit coral larvae on the coral growing structure 1.

  The shading plate 8 is attached only during a period when the sunlight is strong in summer or when the coral larvae are landed. Attachment and removal to and from the pole 5 are performed by inserting and removing the light shielding plate 8. In order to facilitate insertion and removal, the light shielding plate 8 is loosely inserted into the pole 5 and supported from below by a nut screwed into the pole 5. Further, a nut may be screwed into the upper side so that the light can be fixed securely, and the light shielding plate 8 may be sandwiched and supported by the upper and lower nuts screwed into the pole 5.

  The coral growing structure 16 shown in FIG. 8 has the same structure as the coral growing structure 1 shown in FIG. 1 except that the rectangular frame 2 of the coral growing structure 1 shown in FIG. Thus, like the coral growing structure 1 shown in FIG. 1, the shaft-shaped poles 5 are fixed to the coral growing structure 16 so as to protrude vertically in three locations, preferably at equal intervals in the circumferential direction. When installing on the seabed, the pole tip is inserted into the seabed and fixed, and the coral cultivation structure 16 is supported away from the seabed.

  The coral cultivation structures 1 and 16 may be attached to the pole 5 alone as shown in FIGS. 1, 3, 4 and 8, or may be attached to the top and bottom of the pole 5, A plurality may be installed side by side in the horizontal direction. When a plurality of upper and lower corals are attached to the pole 5, it is desirable to provide a gap between the upper and lower coral growing structures so that small fish do not enter from the lateral direction. As a result, the same effect as that of the depth of the grid 3 can be reduced, that is, the damage caused by small fish can be reduced.

  In the coral cultivation structure 1 or 16 of the above embodiment, the mesh 3 is rectangular, but in another embodiment, the grid is formed in a diamond shape by intersecting the vertical beam and the horizontal beam at an appropriate angle. In this embodiment, the coral-growing structure is a honeycomb in which a honeycomb-shaped crosspiece formed with the same plate width as that of the frame 2 or 17 is disposed in a rectangular frame 2 or a circular (may be oval) frame 17. In another embodiment, a plurality of rectangular or circular bars having the same plate width as the frame and different in size similar to the frame are formed in the rectangular frame 2 or the circular frame 17 in another embodiment. Concentric circles are arranged, and each beam is connected in a radial manner with another linear beam, and is formed of a structure formed as a trapezoid or arc.

The coral growing structure 1 or 16 can be fixed to the pole 5 using the collets 13 and 14 shown in FIG.
FIG. 8 shows an example in which the coral-growing structure 1 or 16 is fixed to the pole 5 using the collet 13 shown in FIG. 5, and the fixing is performed by combining the collet 13 divided in two and attaching the pole 5 from both sides. In the state of being held, the coral-growing structure 1 or 16 is pushed into the cell 3 from below, or the cell 3 is pushed into the collet 13 from above and fixed or temporarily fixed (if temporarily fixed, as shown in the figure) If the pole 5 is stood in a stable state, the corrugated structure 1 or 16 is lowered by its own weight, and is fixed by the wedge action of the corrugated structure 3 or 16 having a draft angle and the taper of the collet 13. Is possible). After fixing, another coral growing structure 1 or 16 is inserted into the pole 5 and fixed via the spacer 19.

  As shown in FIG. 10, the spacer 19 has a cross-sectional shape similar to the cross-section of the mesh 3, and a main body 19 a that tapers upward and projects downward from the lower end of the main body. The main body 19a is formed with a fitting portion 19b that is stepped on the mesh 3 from above, and a shaft hole 21 having a diameter larger than that of the pole 5 is formed through the shaft in the vertical direction. Yes. The spacer 19 can be inserted from below into the mesh 3 having a draft angle in which the main body 19a expands toward the lower end. The spacer 19 is supported when inserted by a certain amount, and cannot be further inserted. It can be fixed to the head by a wedge action.

  When the coral growing structure 1 or 16 is attached to the pole 5 in two upper and lower stages, first, the first coral growing structure 1 or 16 is fixed to the pole 5 using the collet 13 as described above. Next, the spacer 19 is inserted into the pole 5 from above with the fitting portion 19b facing downward, and the fitting portion 19b is fitted from above into the mesh 3 of the first-stage coral growing structure 1 or 16. After that, the second-stage coral cultivation structure 1 or 16 is inserted into the pole 5 with the ribs 3 applied. When the mesh 3 is fitted into the spacer body 19a from above and pushed in strongly, the second-stage coral growing structure 1 or 16 is fixed by the wedge action. In this way, as shown in FIG. 9, the upper and lower coral growing structures 1 or 16 are fixed to the pole 5 with a certain distance in the vertical direction.

  Unlike the spacer 19 shown in FIG. 10, the upper and lower coral growing structures 1 or 16 are fixed as shown in FIG. 12 by using the spacer 22 shown in FIG. 11 that does not have the shaft hole 21 unlike the spacer 19 shown in FIG. 10. It is desirable to support at intervals of.

  According to the present embodiment, the coral cultivating structure 1 or 16 attached to the pole 5 in two upper and lower stages has a total thickness of twice the thickness of the coral cultivating structure 1 or 16 with a gap between the structures. As a result, it is difficult for small fish to enter deeper than the top and bottom surfaces, and coral larvae and polyps that are deeply buried are less likely to encounter food damage. Such an effect is more likely to occur as the coral growing structures 1 or 16 are stacked in multiple stages.

  FIG. 13 shows an example in which the coral cultivating structures 1 shown in FIG. In this embodiment, each coral growing structure 1 located in the corner is supported by poles 5 at the four corners, but each of the coral growing structures 1 at the four corners or each coral growing structure 1 is provided by one pole 5. The central portion may be supported, or may be supported by a plurality of poles 5 other than four. Further, the coral growing structure 1 other than the corner is connected to the coral growing structure 1 of the corner or the coral growing structure 1 connected thereto by the connection fittings 23 and 24. Similarly to the coral growing structure 1, the pole 5 may be supported.

  FIG. 14 shows an example in which the coral growing structure 1 in the middle part of the front, rear, left and right is omitted in the coral growing structure 1 arranged side by side as shown in FIG.

  FIG. 15 shows an example in which a light shielding plate 26 that covers the entire coral cultivation structure 1 is attached to the coral cultivation structure 1 arranged side by side in the front, rear, left, and right directions using the pole 5 as shown in FIG. It is.

1, 16 .. Coral growing structure 2, 17, frame 3, mesh 5, pole 7, ingress prevention device 8, 26, shading plate 11, sleeve 13, 14, collet 19, 22 ..Spacers 23, 24

Claims (4)

  A coral cultivating structure installation method comprising: supporting a coral cultivating structure made of a lattice-like structure so as not to contact the seabed by a pole, and installing the structure away from the seabed.   A coral cultivation structure used in the coral cultivation structure installation method according to claim 1, comprising a lattice structure, attached to the lattice structure, and supporting the lattice structure An umbrella or umbrella bone-shaped entry prevention device is installed between the seabed and the lattice structure to prevent the propagation of pests such as sea starfish, sea urchins, and shellfish that damage the growth of coral larvae. Coral cultivation structure.   A sleeve that is loosely fitted to the pole to support the entry prevention device, and a collet that is divided into a plurality of circumferential directions and is pushed into the sleeve in a state of being assembled around the pole; 3. The coral growing structure according to claim 2, wherein at least one of the inner periphery of the sleeve and the outer periphery of the collet is tapered in the vertical direction.   The pole protrudes up and down through the lattice structure, and a light-shielding member that prevents the sunlight from hitting the lattice structure is detachably attached to a portion protruding above the lattice structure. The structure for coral cultivation according to claim 2 or 3, characterized in that