JPH0320211B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention can create effective places for raising young fish and gathering fish colonies, such as spawning grounds for fish and shellfish, feeding grounds for juveniles, hiding places, etc. as places for reproduction of aquatic animals. It is about fish reefs. [Conventional technology] In ancient times, fish reefs have been used in limited areas as rock formations or Phayao fishing methods, but especially in recent years, with the 200 nautical mile coastal method, fish reefs have been used as a powerful means of increasing productivity on the continental shelf, such as cultivation fishing and marine ranching. The fish reef technology is shown in close-up. These fish reefs come in both submerged and floating types, and are being actively developed using various materials such as natural materials, synthetic resins, and concrete. [Problems to be Solved by the Invention] Conventional floating fish reefs are made of bamboo, nets, synthetic resins, inorganic moldings or foams, etc., but in common they have poor attachment and growth of marine organisms. In the case of bamboo, its durability is extremely low at around 2 to 3 months.
In the case of nets, they are usually used vertically, so the shading effect is small and buoyancy materials are required. In addition, the size of synthetic resin molded products is limited due to the capacity of injection molding machines, and foams cannot withstand deep water pressure due to seawater penetration into bubbles and low compressive strength. limited to use. In order to compensate for this drawback in terms of pressure resistance, it has been proposed to provide a coating with a highly rigid synthetic resin, or to mix inorganic materials such as sand with the resin coating to improve the adhesion of marine organisms.
It is difficult to put it to practical use due to resin molding technology, and it is not as good at attracting marine organisms as sand, clay, etc. Furthermore, inorganic foams such as foamed lightweight concrete are susceptible to seawater penetration and are heavy, which poses problems in terms of durability and handling. The present invention eliminates these drawbacks and easily constructs a floating fish reef that has high buoyancy and durability, is effective for the collection of fish schools, the settlement and growth of algae, the growth of young fish, etc., and is lightweight and easy to handle. It is provided in an inexpensive form. [Means for solving the problem] The present invention comprises 100 parts by weight of a synthetic resin, 20 to 250 parts by weight of one or more fine inorganic powders selected from calcium carbonate, calcium sulfite, or gypsum, and a blowing agent. This is a fish reef characterized in that it is made of a foam composition kneaded with a floating fish reef that can float. [Example] The foaming composition contains 20 to 20 parts by weight of one or more inorganic fine powders selected from calcium carbonate, calcium sulfite, and gypsum (dihydrate gypsum, hemihydrate gypsum, anhydrite) based on 100 parts by weight of the synthetic resin. 250 parts by weight, preferably 40 to 120 parts by weight, and a blowing agent, crosslinking agent, kneading aid, etc. are added, and the foam is foamed to a foaming ratio of 10 to 20 times, preferably about 15 times. The bulk specific gravity of this foam composition is 0.11 to 0.15 g/cm ³
Therefore, even considering the weight of the frame, underwater deposits, rope, etc., it can float sufficiently, and its compressive strength, bending strength, bending elastic modulus, tensile strength, surface hardness, water absorption rate, etc. are sufficient for practical use. It is something. In addition, the following numerical values can be mentioned as practical values of this kind of thing.

[Table] The bubbles in the foam composition have a bounding membrane thickness of about 5μ,
On the membrane surface, a very large number of fine, flat calcium-based inorganic particles are exposed parallel to the membrane surface and are uniformly distributed throughout the foamed composition. As the synthetic resin, polyolefin resin is preferable from the viewpoint of erodibility by living organisms, water resistance, economical efficiency, etc. Polyethylene, polypropylene, ethylene-based resin, etc.
Vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-acrylic acid ester copolymer,
Common polyolefins such as ethylene-butene copolymers or copolymers of olefins and other monomers are used. As the inorganic fine powder, one or a mixture of two or more selected from calcium carbonate, calcium sulfite, and gypsum (dihydrate, hemihydrate, anhydrite) is used. Calcium or a calcium compound is used because it is non-biotoxic, biocompatible, hydrophilic, and has an appropriate solubility in water. In these cases, if the mixing ratio of synthetic resin and inorganic fine powder is less than 20 parts by weight of the latter compared to 100 parts by weight of the previous article, the effect of biological compatibility will be insufficient, and if the latter is more than 250 parts by weight, it will not work as a floating fish reef. It should be avoided as it will not have sufficient durability. Further, as the blowing agent, for example, azodicarboxylic acid amide, as the crosslinking agent, for example, dialkyl peroxide, as the lubricant, zinc stearate, and as the kneading aid, ethylene acetic acid copolymer is selected and used. An example of the composition of a foaming composition is as follows: weight (%) polyolefin resin 39 calcium carbonate 58 blowing agent 1.7 crosslinking agent 0.4 lubricant 0.4 kneading aid 0.5. Next, specific examples of fish reefs will be explained using drawings. A plurality of foamed compositions 1 made of the above-described foamed composition formed into flat panels are fixed in multiple layers to a frame 2 made of metal, resin molding, etc.
form. When attaching one group of foamed compositions to the frame 2, a space 3 with an appropriate interval between the foamed compositions 1 and 1 is used.
However, a locking member is provided on the vertical member of the frame 2,
A spacer or the like can be provided movably or detachably to facilitate adjustment of the height of the space 3. Further, the frame 2 is provided with a connecting member 4 so that a plurality of units A can be connected horizontally and vertically to form a fish reef of a required size. Unit A or a group of connected units A configured in this way is attached to a submarine anchor 6 using a mooring rope 5.
It is moored to the water and placed floating under the liquid surface. When mooring, it is sufficient to anchor and moor at least one place on the reef consisting of unit A or a group of units A, but it is also possible to anchor one or more anchors at multiple points using multiple ropes 5. It can also be locked. As the locking portion, the connecting member 4 or the main body of the frame 2 may be used, or a dedicated locking portion may be provided. In addition, when the units A are connected and used, they can be connected in the sea area where they are installed, or they can be connected and assembled on a quay and towed, for example, like a raft. The installation water depth can be adjusted by adjusting the weight of the frame 2 and the rope 5, or the length of the rope 5, and is preferably installed at a water depth of 10 m or less. The height of the space 3 is adjusted depending on the purpose of use, but for example, in one unit A, the height of the space 3 can be made smaller in the upper part and larger in the lower part. The frame 2 is preferably a frame made of a bar or tube that does not close the space 3, but in some cases a member forming a wall may be used. The shape of the foamed composition 1 is not limited either, and a ring shape, a block shape, a block shape with a space, a shape integrally provided with a convex part for forming a space, etc. may be used, and irregular shapes may also be used. It is also possible to form it by combining various things. As the calcium salt is eluted into the water from the water contact area in small amounts, the microscopic surface of the foamed composition 1 becomes like a natural stone hole, which facilitates the settlement of plankton spores, zoospores, etc. Because of the anchoring effect in the stone hole, it is grown without falling off due to waves, air bubbles, etc. The area in contact with the sea surface water, which has a relatively high concentration of dissolved oxygen, provides a good habitat for fungi, general algae, protozoa, etc., where the food chain functions smoothly in an aerobic manner. This provides favorable environmental conditions for the collection and growth of young fish. In particular, by reducing the height of the space 3, it is possible to reduce the possibility that young fish will be preyed upon by adult fish. On the other hand, the multi-layered structure and increased installation area provide a shading effect, a seawater eddy effect, haptaxis and feeding effects for attracting fish, and a great effect on attracting adult fish can be obtained. Furthermore, by connecting units, the reef can be made to any size, and handling is extremely convenient. The example in FIG. 3 is an example in which a unit A is formed from a sheet of foamed composition 1 and a frame 2. Next, an experimental example regarding the biocompatibility of the foam composition of the present invention as the main material will be shown. Iron contact aeration tank (length 120cm width 150cm depth 100cm)
20 diffuser tubes were placed at equal intervals of 25 cm at the bottom of the tank, and COD 20 ppm, SS 10 ppm, and surfactant containing COD 20 ppm, SS 10 ppm,
Polluted water with a pH of 7.2 and a water temperature of 20 to 30° was supplied at a volumetric rate of 0.5 KL/hr, and air was supplied from the aeration pipe at a rate of 6 m ³ /hr with an average bubble diameter of approximately 1 mm. In the tank in this state, thin round rods with a diameter of 3 mm and made of various materials shown in the table were assembled in a lattice shape to form a biological support net, which was fitted into a stainless steel frame and assembled at intervals of 5 cm. While the wastewater was aerated in this tank, the growth state of biofilms attached to the nets made of various materials was observed after 10 and 20 days.

〔Effect of the invention〕

The present invention is extremely effective for the growth and growth of marine organisms, has good adhesion growth for seaweed, and serves as a hiding surface and swimming surface for fish, making it suitable for fish habitat, increasing the effect of attracting fish, and promoting the reproduction of aquatic animals. In addition to contributing to the creation of breeding reefs, guidance reefs, and fishing reefs as production sites, it also creates habitats that suit the habits of fish, is suitable as a protection and breeding ground for young fish, and provides an easy-to-handle and inexpensive floating fish reef. Therefore, it can greatly contribute to the expansion and aquaculture of marine resources and coastal fisheries.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a longitudinal sectional view of the device in use, FIG. 2 being a partial perspective view, and FIG. 3 being a perspective view of another embodiment. DESCRIPTION OF SYMBOLS 1... Foaming composition, 2... Frame, 3... Space, 4... Connecting member, 5... Rope, 6... Seabed anchor.

Claims (1)

[Claims] 1. A foaming composition obtained by kneading 100 parts by weight of a synthetic resin, 20 to 250 parts by weight of one or more fine inorganic powders selected from calcium carbonate, calcium sulfite, or gypsum, and a foaming agent. A fish reef characterized by being configured as a floating fish reef. 2. The fish reef according to claim 1, wherein the foam composition is a combination of plate-like panels, rings, or blocks, and is attached to a frame. 3. The fish reef according to claim 2, wherein the foam composition is a flat plate and is fixed to the frame in multiple layers through spaces to form a unit. 4. The fish reef according to claim 2 or 3, wherein the foam composition is arranged in balance with the weight of the frame so that it can float under the liquid surface in an immersed state. 4. The foam composition is formed into flat panels, which are assembled into a block with a multi-layered structure at predetermined intervals using a frame, and the intervals can be freely adjusted by changing the fixing position of the panels. A fish reef according to any one of claims 1 to 4.