JPH0332973B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to the use of sunken reefs or reefs for construction that are effective as spawning, hatching, growth of young fish, collection of adult fish, and feeding grounds for fish, or of reefs along the waterline. This invention relates to a molded seaweed bed for rock seaweed cultivation.

[Conventional technology]

Conventional sunken fish reefs are made of natural stone, concrete, iron, single or composite structures, old tires, etc., placed in established water areas, and algae are left to grow naturally, forming seaweed beds. Furthermore, in conventional fish reefs, a synthetic fiber net or a high-density resin material is placed in the target water area, and algae are left to grow naturally to form a seaweed bed. and,
Only naturally occurring species such as Koji nori, commonly known as rock nori, and Habanori, which are collected in the winter season, were considered.

[Problem that the invention seeks to solve]

With the exception of medium-natural stone, which has been conventionally used as a reef material, the formation of seaweed beds was generally slow and poor. In other words, in the case of concrete, a rough surface is formed through the scum removal process and algae growth is favorable for one to two years, and after that, algae growth decreases due to rock formation. In the case of iron, algae growth begins after the surface corrosion process. In addition, old tires, synthetic resin nets, etc. have smooth surfaces and do not change over time, so algae can grow on them through the attachment of shellfish such as barnacles.

In general, a thriving seaweed bed is an essential environmental condition for the collection of fish and the proliferation of useful aquatic animals. This is a problem that has a serious impact on the amount of fish caught.

Next, conventionally, the collection of seaweed from rocky shores in areas with cold winters has only been done by hand, and it has only been done by hand. They remained there, and the work to collect them was extremely dangerous due to poor footing.

The present invention solves the above-mentioned drawbacks of the conventional products, and is designed to accelerate the settlement and growth of algae on fish reefs by wrapping materials for sinking various types of fish reef materials with seaweed bed moldings, or by attaching weights to the seabed to form a flat surface on the seabed. To provide highly economical fish reefs, etc. by laying a seaweed bed on the ground and allowing algae to grow naturally there, or by seeding it with predetermined algae in advance and allowing it to settle. The purpose is to

[Means for solving problems]

The present invention involves twisting a kneaded mixture composition of 100 parts by weight of a synthetic resin and 20 to 250 parts by weight of fine powder of an inorganic calcium salt, forming a net-like or bag-like molded body using the threads, and Collect seaweed seedlings,
It is a seaweed bed fish reef characterized by including fish reef material.

[Effect]

When the seaweed bed molded body of the present invention is put into seawater,
The calcium salt fine powder of the molded body swells and partially elutes in the water-contacted area, leaving elution traces in the shape of holes in natural stone. The surface structure of this hole is extremely suitable for the growth of epiphytes or filaments of spores such as algal monospores, zoospores, zygotes and carpospores, and grain spores, and for the anchoring effect of young buds from them. It is stable against ocean currents and waves, and grows well without so-called bud drop. In addition, there is very little bud drop during the various operations from seedling collection to offshore.

That is, according to microscopic observation using an electron microscope, when looking at molded products containing calcium sulfite,
The filler was distributed smoothly on the surface before being immersed in the water of the aeration tank, but after being immersed, unevenness and numerous tunnel-like holes were observed _. The pH decreases due to the influence of NO ₃ , etc., and some of the calcium sulfite as a filler becomes calcium sulfate and becomes solubilized, creating stone hole-like defects on the surface. It was confirmed that stable and good growth was achieved due to the hydrophilicity of the Ca contained in the seedlings.

Further, the molded article of the present invention can be sown with predetermined seedlings in a seedling tank after removing scum in advance with seawater or fresh water. For example, for red sea bream and black sea bream, algae such as eelgrass and koammo are used for sea bream, and for turban shell,
For abalone, seeds and seedlings of algae suitable for aquatic animals to be collected or propagated, such as abalone, sardine, and sargassum, can be used.

〔Example〕

As the synthetic resin, polyolefin resins or vinylon resins are preferable from the viewpoint of erodibility by living organisms, water resistance, moldability, economic efficiency, etc. Specific examples of the former include polyethylene, polypropylene, ethylene/vinyl acetate copolymer, and ethylene/propylene. Common polyolefins such as copolymers, ethylene/acrylic ester copolymers, ethylene/butene copolymers, or copolymers of olefins and other monomers are used.

As the fine powder of inorganic calcium salt, one or a mixture of two or more selected from calcium carbonate, calcium sulfite, and gypsum (dihydrate, hemihydrate, anhydrite) is used.

The mixing ratio of these synthetic resins and inorganic calcium salt fine powder is 100 parts by weight of the former and 20 parts by weight of the latter.
If the latter is less than 250 parts by weight, the biocompatibility effect will not be exhibited, and if the latter is more than 250 parts by weight, it will not have sufficient strength in water and should be avoided.

Note that it is also effective to form uneven portions on the surface of the molded product, and when molded into a fiber shape, any of monofilament, multifilament, and spread yarn may be used. In particular, multifilament,
It is particularly preferable to twist spread yarns into twisted yarns.

Next, embodiments of the present invention will be described using the drawings.

In FIG. 1, as a reef material 2, natural rocks or other reef materials such as concrete blocks are wrapped in the molded body 1 of the present invention, tied together with nylon ropes 4 if necessary, and deposited on the seabed of a target water area.

The method of sinking is to drop it from a ship in the target water area, but if necessary, it can be hung by tying a drop rope or wire to the rope 4, or it can be suspended from something like Motsuko, for example.
It may be placed for more than a month and then submerged.

The seaweed seaweed reef of the present invention on the seabed has the characteristic that it adapts extremely well to the seabed topography except on steep slopes where the main body may slide down, and remains stable even in the presence of rocks 3 and the like.

Additionally, after being sunk, small gaps are created on the seabed or between the bodies, which provide a safe habitat for benthic organisms and young fish.

In addition, some of the fish reefs of the present invention are shown to be overgrown with algae.

FIG. 2 shows the molded product of the present invention (bamboo-shaped or lattice-shaped is best) 1 being developed with a molded product development rod 4'.
A concrete block 6 made of fish reef material as a weight is tied under it, and the concrete block 6 is placed at a fixed position while being suspended from the ship using a rope 5 in the target water area.

The seaweed bed and fish reef of the present invention on the seabed of the present invention has the feature that it adapts extremely well to the seabed topography, except for the steep slopes on which the main body slides, and that the area can be effectively secured even in the presence of rocks 3 and the like.

Furthermore, in the case of cultivating rock seaweed such as Kosujinori and Habanori, since the growing place is in the water age line of rough winter waves, it is sufficient to fix the rockweed to resist wave force.

In addition, in the molded body 1, swelling and partial elution of the calcium salt by seawater or fresh water proceed in the water-contacting part of the calcium salt fine powder, and the elution trace becomes like a natural stone hole and contains monospores, zoospores, zygotes, and algae. It is extremely suitable for the propagation of epiphytes or filaments of spores such as fruit spores and grain spores, and for the anchoring effect of young buds from them. It is stable against environmental conditions such as ocean currents and waves, and does not cause bud drop, making it possible to minimize bud drop during various operations from seedling collection to offshore.

〔Effect of the invention〕

The present invention involves twisting a kneaded mixture composition of 100 parts by weight of a synthetic resin and 20 to 250 parts by weight of fine powder of an inorganic calcium salt, forming a net-like or bag-like molded body using the threads, and Collect seaweed seedlings,
In addition, by including the fish reef, by making it into a twisted thread, it is stretched and the inorganic calcium salt is easily exposed on the surface, and inorganic substances such as calcium do not fall off, and in the twisted thread, countless recesses are stretched and expanded. The protruding part of the kneaded calcium will become a hole when it is solubilized, and the stone hole can also have an anchor effect, and it can be used to collect seaweed seedlings, so if you use it for a fish reef, you can grow the target fish species in a short period of time. A natural seaweed bed is formed by applying the method, or a seaweed bed for the growth of young fish can be easily formed in a short period of time. Furthermore, the product of the present invention has the advantage of being water resistant and durable, and can be used for a long period of time, and that algae germinate well and grow quickly. In addition, fewer buds fall off during facility work, making the work easier.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of a usage mode of the product of the present invention, and FIG. 2 is an explanatory diagram showing an example of another usage format. 1... Seaweed bed molded body, 2... Fish reef material, 3... Rock, 4... Rope, 6... Concrete block.

Claims (1)

[Scope of Claims] 1. A kneaded mixed composition of 100 parts by weight of a synthetic resin and 20 to 250 parts by weight of fine powder of an inorganic calcium salt is made into a twisted thread form, and a net-like or bag-like molded body is formed therefrom, A seaweed bed and reef, characterized in that the molded body contains seaweed seedlings and a fish reef. 2. The seaweed bed and reef according to claim 1, wherein the molded product is laid out and installed in a planar shape having a predetermined area, and the reef material is attached at predetermined intervals. 3. The seaweed bed and reef according to claim 1, wherein the synthetic resin of the mixed composition is a polyolefin homopolymer or a copolymer consisting of an olefin and a monomer other than olefin. 4. The seaweed bed and reef according to any one of claims 1 to 3, wherein the inorganic calcium salt is arbitrarily selected from the group consisting of calcium carbonate, calcium sulfite, and gypsum.