JP4948945B2 - Restoration, creation and maintenance methods for biodegradable eel nursery sheets and eelgrass beds - Google Patents

Description

TECHNICAL FIELD The present invention relates to a biodegradable eel nursery sheet and a method for repairing, creating and maintaining a eelgrass field using a biodegradable eel nursery sheet. More particularly, the present invention relates to biodegradable plastic fibers that are hydrolyzed or enzymatically oxidized by enzymes in the environment and whose degradation intermediates are degraded in the metabolic pathways of the organism , and biodegradable natural cellulose fibers. A sheet of eelgrass seeds on a sheet of blended fiber, cultivated and cultivated on land for a certain period of time, and grown from a strong eel seedling and a biodegradable sheet grown to a size that can be transplanted to the seabed of the inner bay shallow water The present invention relates to a biodegradable eel nursery sheet and a method for repairing, creating, and maintaining a eelgram field using such a biodegradable eel nursery sheet.

  Ammo (Zostera marina L.) community is a submerged, hermaphroditic perennial that grows in seawater in the range of 2-3 m below the low tide line from the lower intertidal zone at the back of the coastal bay in Japan. A kind of eelgrass has priority over the composition of eelgrass groups. The bottom sediments are thick mud and fine sand. Sea lion communities are the main seaweeds (aquatic plants) of the so-called seaweed beds. Overwinter with seeds and rhizomes. It can grow to a depth of about 10 meters. The rhizome is thick, firm and flat, major axis 5-8cm, minor axis 3-5cm. Dredging vertically and horizontally in sand mud several centimeters below the seabed. Amamo grows from spring to May and declines in autumn. Seeds dormant in summer. The seeds are rice-grained, 3-5 mm long, endosperm-free seeds, the hypocotyl becomes storage tissue, and contains a large amount of starch and protein. Number of chromosomes 2n = 12. Also known as Mosiogusa (algae herb), Ryugu Unotohimenomoto Yuinokihashi Hashishi (cutting off the dragon princess Otohime), Moba, Hamayu (Source: End of Otaki et al., Published by Kitatakakan, "Japan Aquatic Plants Picture Book", Akira Miyawaki (Excerpted from "Japanese Plant Community Illustrations" published by other authors Tobundo, "Revised New Japan Plants Picture Book" published by Tomitaro Makino, published by Kitatakakan, and "Japan Plant Seed Picture Book" published by Tohoku University Press).

  The core duck (Zostera japonica Aschers. Et Graebn) is a submerged herbaceous perennial that grows in seawater in the range of 5 cm to 2 m below the low tide line from the lower intertidal zone at the back of the Japanese coastal bay. The composition of the core peach community is given priority by one core mao. It is established in seawater that is shallower than the eelgrass community, and the sediment is thick and thick. Like sea cucumber, it is the main seaweed (aquatic plant) of the seaweed bed. Overwinter with seeds and rhizomes. The rhizome is thin and hard. It is dredged vertically and horizontally in fine sand with a diameter of 1 to 2.5 mm and several centimeters below the seabed. The flower season is from March to June, and the peak season is from May to July. The seeds are 1.9 ± 0.1mm long, 0.8 ± 0.0mm wide, 0.8 ± 0.0mm thick endosperm seeds, the hypocotyl becomes storage tissue, and contains a large amount of starch and protein . Number of chromosomes 2n = 12. Approximate species are Z. asiatica Miki and T. caulescens Miki. Another name is Niramok and Moku (Source: the same as above).

Shrimp (Phyllospadix japonicus Makino) is a reef zone from the west to the coast of Kitakyushu connecting Ibaraki and Niigata prefectures in Honshu . Overwinter with rhizomes . The rhizome is thick and short, about 2-3 cm in diameter. The flowering period is from March to April. The seeds are about 3.5 mm long, endosperm seeds, the hypocotyl becomes a storage tissue, and contains a large amount of starch and protein. Number of chromosomes 2n = 20. An approximation species is P. iwatensis Makino. Other names include Hyugasugamo, Komogusa, Maxa, Umisuge, etc. (Source: the same as above).

Accordingly, the term “amamo” used in the present invention includes the genus Amamo (Zostera marina L.), Zostera caespitosa, Zostera japonoca Aschers. Et Graebn. Zostera L.), and Sugamo (used as Phyllospadix iwatensis Makino) and mainly includes collectively Sugamo genus (Phyllospadix Hook) containing Ebiamamo (Phyllospadix japonicus Makino). Depending on the classification, Ryukyu Amamo and Shrimp Mama may be classified as Ikuzu. Ajimo, mosquito (algae herb), Ryugu no Otohimenomoto Yuinoki Hakushi (cutting off the dragon princess Otohime), moba, kingfish, komogusa, makusa, umisuge, etc. that have been used in Japan since ancient times. (Common use).

  Amamo is a seed plant, not an algae that grows on spores. In early spring, part of the plant body turns into flower branches to form seeds. Seed length 1.9 ± 0.1mm, width 0.8 ± 0.0mm, thickness 0.8 ± 0.0mm, weight 36mg 36mg, seed is oblong, base is cut, seed coat is Thin vertical stripes are parallel. Seeds germinate in the winter, grow actively from winter to spring, and repeat branching. From spring to summer, it grows, matures, dies and deposits on the seabed, or flows out, and in autumn it becomes only a short plant. There are two breeding methods: seedling (seed seedling) and branching / extending rhizomes to give a new strain (nutrient strain). No vegetative strains are found in the sea where there are some limiting factors such as high water temperature in summer, and the life ends in one year.

  The original coast of Japan is a series of river mouths, creeks, mud flats, Kashihara, tide pools, pine forests, pine forests, sandy beaches, estuary wetlands from the estuary to about 1 km, tidal flats up to about 1.5 km, eelgrasses, offshore bay It made up a rich ecosystem in the inner bay.

  Amamo grows on the shallow seabed about 1.6 km from the sandy beach and 5 cm to 10 m deep. Amamo field is closely related to the shallow water ecosystem in the inner bay. Compared to tidal flats, the shallow waters of the inner bay are characterized by the characteristics of the shallow waters of the inner bay, compared to fish, clams, clams, Relatively large animals such as clams, crabs, and shrimps play a leading role in the ecosystem. Supporting the lives of fish, clams, clams, crabs, shrimps, etc. is the prosperous primary productivity of phytoplankton and seaweed based on the abundant nutrients in the inner bay. The coastal area surrounding the inner bay is a habitat for fish, clams, clams, crabs, shrimps and other juvenile life, and after growing up, there are wetlands and tidal flats that serve as feeding grounds at high tide.

  Seawater purification by tidal flats increases seawater transparency in the surrounding shallow water and forms a seagrass bed where sea lions grow densely. This seagrass bed is a place for various animals and has the ability to increase the diversity and productivity of living organisms in shallow water. Furthermore, the shallow waters of the inner bay are also important as a plankton larval habitat for animals inhabiting wetlands, tidal flats, and inner bays. In this way, a series of wetlands, tidal flats, eelgrasses, and offshore inner bays bring a rich ecosystem to the inner bay, which is the natural inner bay structure. Inner bay animals are used effectively by moving in these waters as they grow, which is the source of abundant inner bay fishery resources.

  It is required for the growth of eelgrass that the bottom of water and sandy mud is clean, and that the coastline and shallow water are not disturbed by artificial structures such as wave-dissipating blocks and concrete quays. It is considered as one of the environmental indicators in the inner bay shallow water area.

  However, most of the coastal areas surrounding Japan's inner bays have become urbanized, and after the post-war high economic growth, large-scale coastal shallow waters have been reclaimed, and the area of eelgrasses has greatly decreased. As a result, the above-mentioned environmental purification function that the Amamo field has been playing in the past is lost, and serious problems have arisen in maintaining marine resources and environmental conservation. For example, even in Tokyo Bay, the total catch of shellfish, seaweed (aquaculture), algae, fish, and other marine animals totaled approximately 100,000 tons in 1955. It has fallen below 10,000 tons.

  In this way, in the estuary wetlands and tidal flats in Japan, the space itself, which is the foundation of the ecosystem, has been catastrophicly lost due to reclamation and landfilling, and various developments are planned where there are a few remaining. In particular, in areas such as Tokyo Bay, Ise / Mikawa Bay, and Osaka Bay where anthropogenic eutrophication accompanied by the formation of oxygen-poor water mass and the reduction of sediment is remarkable, environmental degradation in the shallow area of the inner bay is remarkable. .

To this end, various research institutions, companies, non-profit corporations, etc. have made various proposals in recent years for the purpose of restoring, creating, and maintaining Amamo fields nationwide. It is necessary to satisfy the following conditions in order to restore, build and maintain this Amamo field.
(1) The so-called “seeding method” in which seeds of eelgrass are simply sown in the sea is difficult to establish as an eelgrass field. This is thought to be due to the instability of germination because seed spillage caused by tidal currents and the sowing environment are not suitable for germination and growth.
(2) For the same reason as (1), the seedlings of sea cucumber are packed in a bag together with the growth base material and placed on the seabed. Lack of sex.
(3) In the case of the so-called “transplantation method” in which vegetative strains are collected from existing seaweed beds and transplanted to the seabed, there is a concern of damaging existing seaweed beds by securing a large amount of seedlings, and the transplanting work takes time and cost. It takes.
(4) In transplantation of eelgrass seedlings, seedlings are more likely to flow out immediately after transplantation than vegetative strain transplantation due to scouring by waves and tides.
(5) Amamo field is a shallow sea area in the inner bay about 1.5 km from the sandy beach and about 5 cm to 10 m deep. This inner bay shallow water area overlaps with marine sports such as swimming, scuba diving, and fishery grounds for seafood. Therefore, the materials used for the restoration, creation, and maintenance of the eelgram field should not be harmful to human health.
(6) Materials used for rehabilitation / creation / maintenance of eelgrass fields should not maintain the shape for a long time in the shallow waters of the inner bay and deteriorate the marine environment or the ocean / underwater landscape. .

  From this point of view, some of the prior art will be considered.

  Patent Document 1 generally outlines artificial soil mixed with a porous natural material, seabed soil, and a binder made of gypsum (calcium sulfate dihydrate) into each space of a divided small pallet to contain seawater. , Planting seeds of sea cucumber, reacting calcium sulfate and seawater to bind the artificial soil planted with sea urchin seeds in a lump, then installing a pallet in sea water, changing the water temperature to grow sea cucumber seeds, It describes a method for growing seaweeds and seaweeds in which artificial soil is introduced into the seabed from the ship when roots and germination of eelgrass leaves and roots have grown.

  In the case of this conventional method, gypsum that forms artificial soil uses the formation of solidified matter with seawater, but this solidified matter itself becomes a foreign substance in the sea, and the idea of purifying, preserving, and repairing eelgrass fields Contains contradictory elements. In addition, sea eels are 2-6m deep, cored ducks are 1-2m deep and shrimp ducks are 1-10m deep. It is also dangerous to have.

  Patent Document 2 generally has a specific gravity of about 1.3 or more, which is the specific gravity of seeds, which is a mixture of a viscous soil containing marine seed plant seeds and dredged soil, a solidified material mainly composed of gypsum, and a water-soluble polymer. It discloses a marine seed plant growing material, a method for producing a marine seed plant growing material, and a method for creating a marine seed plant growing field, which are summarized in that about 2.3 granulated materials are put into the sea area.

  In the case of this conventional method, the specific gravity of the marine seed plant growing material in which the seeds of the marine seed plant are embedded is about 2.3. Therefore, theoretically, the material does not run off after being put into the sea area, but temporarily stays on the seabed. . However, it does not grow stably in one place due to waves or ocean currents, and there is variation in the growth. Therefore, it is impossible to systematically clean, maintain, and repair Amamo fields.

  Patent Document 3 generally describes a method for purifying a coastal sea area in which a sea eel seed is sown or transplanted in a coastal sea area contaminated with toxic substances such as heavy metals to form a sea eel field.

  As in this conventional method, simply seeding sea lion seeds in the sea is not suitable for germination and breeding because the seed drainage and seeding environment due to tidal currents are not suitable for germination and breeding, so it is difficult to establish an ammo field, or When sea eels are collected from existing seaweed beds and transplanted to the seabed, there is a concern of damaging the existing seaweed beds by securing a large amount of seedlings, and the transplanting work takes time and cost.

  Patent Document 4 describes an underwater plant growing medium in which, in general, eelgrass seeds, granulated slag, and weights are housed in a hemp bag and the opening is closed with hemp string.

  This conventional method is not much different from the method of simply sown seedlings in the sea, and the seed drainage and seeding environment due to tidal currents are not suitable for germination and breeding, so germination is not stable and it is difficult to establish an eelgrass field. And since granulated slag hardens and hydrates for a long time, it is not preferable for the seabed environment.

  Patent Document 5 has the same drawbacks as the conventional method of Patent Document 4.

  Patent Document 6 describes, in general, seaweed beds for sea cucumber using a self-disintegrating porous concrete block composed of an aggregate and a binding material of an alkali silica reactive mineral such as waste glass.

  In the case of this conventional method, there are too many uncertainties and lack of certainty for the sea eel seeds to be implanted and grown. In addition, the water depth of 1 to 10 m where the eelgrasses such as sea bream, core eel, and shrimp moth are clustered is a shallow water area where a person swims or fishes. When this porous concrete block is installed in the shallow water area, it takes a long time to completely self-collapse to a size that is not dangerous to the human body, and it is dangerous to exist as a semi-permanent structure during that time .

  Patent Document 7 describes a method for planting an eelgrass by transplanting an eelgrass seedling into a collapsed block.

  This conventional method also has the same drawbacks as Patent Document 6.

  Patent Document 8 generally describes a multi-cavity block in which water-retaining mortar or concrete is partially bound and a large number of cavities are dispersedly formed in a molded body, and sand mud loaded in a cavity of the multi-cavity block. It describes the planting base for sea cucumbers, etc. made of min.

In the case of this conventional method, the same drawbacks as the conventional method of Patent Document 6, that is, in the shallow waters person of depth 1~10m are you collecting work industry swimming or seafood, etc., this mortar or concrete planting foundation In addition to the disadvantage that it is dangerous to the human body, there is a disadvantage that the conditions under which larvae grow on the surface after various protozoa, barnacles and other shellfish are deposited after a long period of time.

  Patent Document 9 outlines that a carbon fiber sheet for eelgrass seedlings composed of eelgrass seeds held on a carbon fiber knitted fabric or a carbon fiber nonwoven fabric, or roots of eelgrass seedlings on carbon fibers of a carbon fiber mat or carbon fiber nonwoven fabric. An eelgrass seedling-fixed carbon fiber sheet composed of eelgrass seedlings fixed by entanglement is described.

  The carbon fiber used in this conventional method is excellent in various physical properties such as corrosion resistance, dimensional stability, chemical stability, strength, rigidity, fatigue strength, wear resistance, and wettability. When used for installation material, it is counterproductive. That is, it remains in the sea almost semi-permanently or floats, deteriorating the marine environment.

  In Patent Document 10, sand mud is put into a biodegradable pot, and a seedling of eelgrass is planted in the sand mud to be grown and used as a nursery bed. On the other hand, the surface of the transplant site of the sandy soil to be transplanted is covered with stone or the like. Thus, a method for constructing an eelgrass field is described in which the seedlings of the grown eelgrass are transplanted together with the biodegradable pots into the holes of the transplantation area.

  In this conventional method, when a vegetative strain is collected from an existing algae field and transplanted to the seabed, there is a concern of damaging the existing algae field by securing a large amount of seedlings, and the transplanting work takes time and cost. Furthermore, until the biodegradable pot breaks down in the sea, even if the amphix rhizomes grow, they cannot go out of the pot. Therefore, the growth and breeding of the eel that should be firmly rooted can be remarkably suppressed when the rhizome is crushed vertically and horizontally in sand mud several centimeters below the seabed. In addition, a hole is made in the seabed to create a transplant site, and the surface is covered with stones, etc., which destroys the seabed in the shallow sea area, which is originally a group of sea lions.

  Japanese Patent Laid-Open No. 2004-133620 generally consists of fixing a limp seed to a biodegradable resin sheet member so as to have a predetermined seeding density, and laying a limp field using a laying device on the seabed to be constructed. The sowing sheet and the sowing method are described.

  In the case of this conventional method, the seedlings of eelgrass are sown on the biodegradable resin sheet member and laid on the seabed where the eelgrass field should be constructed, so that the eelgrass seeds germinate and reliable survival is expected. Before the leaf length grows to 15 to 20 cm, the biodegradable resin sheet member may swell and decompose due to seawater, leaving unstable elements in the growth of the eelgrass field.

  Patent Document 12 outlines that Ryukyuus duck seeds are arranged on a palm mat, a biodegradable coating net is arranged on the seeds, and the coating net and the palm mat are consolidated by a connecting member. Describes a method comprising laying a seaweed breeding platform sandwiching seeds on the seabed.

  This conventional method also has the same drawbacks as in Patent Document 11.

  Patent Document 13 outlines that a flower plant growing place production sheet produced with a coconut shell mat or a coconut fiber vegetation mat is provided with a pot made with a coconut moth mat or a coconut fiber vegetation mat on the sheet surface. Disclosed is a flowering plant growth sheet construction sheet for laying on the sea floor by putting a granulated mixture of cohesive soil containing sea cucumber seeds and dredged soil, gypsum-based solidifying agent and water-soluble polymer. ing.

  In the case of this conventional method, the rhizomes of eelgrass grown in a pot made of coconut husk mat or vegetal fiber vegetation mat are squeezed vertically and horizontally in sand mud several centimeters below the seabed and firmly rooted. Since both of the seats must be penetrated, it takes a burden on the management in the sea until the Amamo field is established.

  Patent Document 14 generally distributes a box-shaped container in which plain woven fabric made of biodegradable polylactic acid fiber is sewn, and puts sand into the container at the home, seeds of amamo seeds, Containers for cultivating eelgrass seedlings and cultivating eelgrass, including covering the top with sand, putting seawater and covering, raising seedlings, and then burying them together in a hole collected from the home and dug in the seabed And how to use it.

  In the case of this conventional method, a considerable number of pits are drilled in the sea bottom of the shallow sea area that will be an ammo field, and the sea floor environment is worsened compared with a method in which the material for growing an ammo field is installed on the sea floor. In addition, it is difficult to control the temperature and water quality of seedlings of eelgrass seeds, and this is not an operation that can be easily repeated with reproducibility in general households.

Patent Document 15 outlines that seeds of eelgrass are sown on a rockwool mat, germinating and raising seedlings on the rockwool mat in a water tank, and the grown eelgrass seedlings together with rock wool mats in the sea or An ammo field construction method characterized by being transplanted to the seabed is disclosed.

  Rock wool used in the invention disclosed in Patent Document 15 is manufactured by adding silica stone to andesite, basalt, etc., melting in an electric furnace at a high temperature of 1400-1600 ° C., and blowing off the molten metal by centrifugal force. Fiber, the component of which is SiO ₂ : 50-40% by weight, CaO: 35% by weight, Al ₂ O _Three : 16% by weight, MgO: 7% by weight, etc. (Edited by Textile Society of Japan, published on March 25, 1994, “Second Edition Textile Handbook”). Therefore, the substance which becomes a nutrient (substrate) when microorganisms grow is scarcely contained. Therefore, it cannot be expected that rock wool itself is completely decomposed by microorganisms into water and carbon dioxide in the sea. Moreover, rock wool may mix | blend steel slag depending on a manufacturing method. Since steel slag contains a small amount of iron, it may rust in the sea, and there is an unstable factor in the durability until the transplanted eel is rooted.
JP-A-2005-87068 JP 2005-95142 A Japanese Patent Laid-Open No. 2004-290802 JP 2005-348625 A JP 2004-236545 A JP 2002-291359 A JP 2003-88260 A JP 2004-267086 A JP 2004-73109 A JP 2003-111530 A JP 10-42626 A JP 2005-348696 A JP 2005-261289 A JP 2006-115707 A JP 63-141523 A

  None of the conventional techniques described in the above-mentioned patent documents satisfy the various conditions required for repairing, creating, and maintaining the above-mentioned Amamo field.

  Therefore, the problem to be solved by the present invention is to improve the above-mentioned drawbacks of the prior art and to establish a method that contributes to the restoration, creation and maintenance of the eelgrass field reliably and easily.

  Another problem to be solved by the invention is to improve the above-mentioned drawbacks of the prior art, and obstruct marine sports such as swimming, scuba diving, and seafood collection without deteriorating the marine environment in the inner bay shallow water area that becomes an ammo field. It is to provide a method that contributes to the restoration, creation, and maintenance of the eelgrass field reliably and easily without using any material.

  Yet another problem to be solved by the invention is that seeds of sea cucumber are sown on a biodegradable sheet, and healthy seedling seedlings cultured and cultivated for a period of time in a simulated sea on land can be transplanted to the seabed together with the biodegradable sheet. It is to provide an ammo nursery that can be moved and subject to commercial transactions, and to provide a method for reliably and easily repairing, creating, and maintaining ammo fields.

According to the present invention, the above problem is solved as follows.
1. Woven fabrics and non-woven fabrics composed of biodegradable plastic fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized, and the degradation intermediates are degraded in the metabolic pathways of living organisms, and blended fibers of biodegradable natural cellulose fibers Or a sheet of woven fabric and seedlings of seedlings seeded on the sheet, cultured and grown for a period of time in a simulated sea in an onshore aquarium, and grown to a size that can be transplanted to the seabed in the inner bay shallow water A biodegradable mallard nursery sheet.

2. In the above item 1, the biodegradable eel nursery sheet has a thickness of 1 to 30 dtex and a length of 20 to 80 mm , and is hydrolyzed or enzymatically oxidized by an enzyme in the environment so that a decomposition intermediate is obtained. The thickness is 5 to 40 mm, the porosity is 90% or more, and the internal space is formed by randomly entangled blended fibers of biodegradable plastic fibers and biodegradable natural cellulose fibers that are degraded by the metabolic pathways of living organisms. The surface seawater conduit is formed.

3. 3. The blend ratio of biodegradable natural cellulose fiber to biodegradable plastic fiber that is hydrolyzed or enzymatically oxidized by an enzyme in the environment and the degradation intermediate is degraded in the metabolic pathway of the organism. Is 5-30 mass% .

4). The biodegradable plastic fiber according to any one of the above 1 to 3, wherein the biodegradable plastic fiber is hydrolyzed by an enzyme in the environment or enzymatically oxidized, and a degradation intermediate is degraded in a metabolic pathway of a living organism. Having a hydrolyzable group containing an oxygen atom, such as ether, amide, urethane, etc., having a constitutional unit of an aliphatic system having 6 or less carbon atoms, having a large oxygen content, and an O / C ratio of 0.3 to 1. It shall be in the range of 0.

5). In any one of 1 to 4 above, the biodegradable plastic fiber that is hydrolyzed or enzymatically oxidized by an enzyme in the environment and the degradation intermediate is degraded in the metabolic pathway of the organism is poly L- At least one selected from the group consisting of lactic acid, polyhydroxybutyrate / valerate, poly (ε-caprolactam), and polybutylene succinate.

6). Laying the biodegradable eel nursery bed sheet described in any one of the above 1 to 5 following the shape of the surface of the seabed that repairs, builds and preserves the eelgrass field in the shallow waters of the inner bay with a depth of about 5 cm to 10 m And fasten with natural material fasteners.

According to the first aspect of the invention, the following effects can be obtained.
1. Biodegradable plastic fibers are blended with biodegradable plastic fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized, and the degradation intermediates are degraded in the metabolic pathways of organisms, and biodegradable natural cellulose fibers. However, the biodegradable natural cellulose fiber has improved the disadvantage of lack of flexibility and insufficient followability to the sea floor, while the high hygroscopic property of the biodegradable natural cellulose fiber makes the fibers , The resistance of the web layer is increased, and the inhibition of larva rhizome penetration is improved by biodegradable plastic fibers.

2. A sheet of biodegradable plastic fibers and biodegradable natural cellulose fibers blended with hydrolyzed or enzymatically oxidized enzymes in the environment and degraded by biological metabolic pathways. Since the seedlings of eel grown in size are nurtured, they can be transferred as a biodegradable eel seedling sheet and become a target for commercial transactions.

3. It is a sheet of biodegradable fiber that is hydrolyzed by the enzyme in the environment and is hydrolyzed by enzymes in the environment, or the degradation intermediates are degraded in the metabolic pathways of organisms. However, it does not worsen the marine environment or marine landscape.

4). The entire biodegradable eel seedling sheet is flat and flexible, and does not have a rigid body, so it can be used for marine sports such as swimming, scuba diving, seafood, etc. Even if it is laid on an ammo ground that overlaps with other fishing grounds, there is no harm to the human body.

According to the invention described in claim 2, the following effects can be obtained.
1. Biodegradable sea cucumber nursery sheet is 1-30 decitex in thickness and 20-80 mm in length and is hydrolyzed or enzymatically oxidized by enzymes in the environment, and degradation intermediates are degraded in the metabolic pathways of organisms. Is formed by randomly entangled blended fibers of biodegradable plastic fibers and biodegradable natural cellulose fibers, with a thickness of 5 to 40 mm, a porosity of 90% or more, and a surface seawater guide to the internal space. Since the water channel was formed, the fresh seawater necessary for the growth of the amphix rhizomes constantly flows as a laminar flow.

2. The specific surface area where the sheet comes into contact with water and the seabed is large, the followability to the unevenness of the sea floor is good, the bottom surface of the sheet is entangled with sand mud particles on the sea bottom, and the sheet-sand bottom sand mud is integrated and adhered The degree is increased.

  According to the invention described in claim 3, biodegradable natural cellulose fibers are biodegradable to biodegradable plastic fibers that are hydrolyzed or enzymatically oxidized by an enzyme in the environment, and degradation intermediates are degraded in the metabolic pathway of the organism. Since the blending ratio is set to 5 to 30% by mass, the growth of the root stem of eelgrass accompanying the increase in entanglement due to fiber wetting by seawater is not hindered, and flexibility is imparted to the entire sheet and adhesion to the seabed is obtained.

  According to the invention described in claim 4, a wide range of aliphatic biodegradable plastic fibers in which the hydrolysis reaction is not only catalyzed and promoted by enzymes in the environment, but also enzymatically oxidized, and the degradation intermediates are degraded in the metabolic pathways of organisms. Can be selected according to various conditions.

According to the invention as claimed in claim 5, the preferred biodegradation according to the invention from the group consisting of poly L-lactic acid, polyhydroxybutyrate / valerate, poly (ε-caprolactam), polybutylene succinate, and mixtures thereof. Can be selected.

According to the invention described in claim 6, the following effects can be obtained.
1. Seedling, culture and breeding of eelgrass seeds are carried out in a simulated sea on land, so that the working environment is good and the growth state of eelgrass can be continuously observed visually.

2. Once the eels have grown into strong seedlings, they will be laid to follow the shape of the surface of the seafloor, which will be used for the restoration, creation and maintenance of the eelgrass field as a seedbed integrated with the biodegradable sheet of the base material. Since it only needs to be fixed with natural material fasteners, subsequent maintenance management is unnecessary and running costs are unnecessary.

3. Using a large-area sheet as the biodegradable sheet as the base material for the biodegradable eel seedling sheet, it can be cut and laid according to the area of the seabed in the shallow sea area to be transplanted, improving work efficiency. The breadth and diversity of work plans are possible.

  Hereinafter, the best mode for carrying out the present invention will be described.

  Since the present invention is characterized in that a biodegradable sheet is used as a base material for the sea cucumber nursery sheet, the biodegradable sheet will be described below. Conventionally, various cellulose fibers have been used as biodegradable materials. Natural cellulose fibers include cotton, Bombax cotton, Kapok and other seed hair fibers, hemp, flax, jute, ramie, mulberry, mitsumata and other gin leather fibers, Manila hemp, New Zealand hemp and other leaf fibers, coniferous and hardwood fibers, etc. Is exemplified. In addition, examples of the artificial cellulose fiber include regenerated cellulose fibers such as viscose silk silk, copper amniray rayon, fortisan and nitrate silk, and semisynthetic fibers such as acetate silk.

Cellulose fiber is a polysaccharide in which glucose is combined with β- l- 4-glucoside, has many hydrophilic groups in the repeating unit, and has high hygroscopicity. Therefore, the seawater may cause the fibers to adhere to each other, increasing the resistance of the web layer and inhibiting plant penetration. Therefore, when the eel nursery sheet manufactured with cellulosic fibers is used alone, it is required to select it appropriately according to the usage mode such as the period of use, the place of use and the purpose of use.

  In addition, Table 1 shows the bonds constituting the biodegradable plastic suitable for use in the present invention and the O / C ratio.

  Many biodegradable plastics use a so-called hydrolysis mechanism that is cut by reacting with water present in large amounts in the natural environment. This hydrolysis reaction is catalyzed and promoted by enzymes in the environment. In addition to hydrolysis by enzymes, those that are oxidized by enzymes can be considered. As the bond that is easily hydrolyzed, a bond containing an oxygen atom such as an ester, carbonate, ether, amide, or urethane is used. In addition, aliphatic substances are preferred in order for decomposition intermediates to be decomposed in the metabolic pathways of organisms, and moreover, plastics having a high oxygen content with a structural unit of 6 or less carbon atoms are susceptible to oxidation. ,preferable. Therefore, the range whose O / C ratio is 0.3-1.0 is preferable.

  Therefore, the biodegradable plastic preferably used in the present invention has a hydrolyzable group containing an oxygen atom such as ester, carbonate, ether, amide, urethane, etc., and an aliphatic system having a structural unit of 6 or less carbon atoms. A plastic having a large oxygen content and an O / C ratio in the range of 0.3 to 1.0 is preferable.

  Low molecular weight aliphatic compounds are generally easily metabolized, have good decomposability of decomposition intermediates, and easily become carbon dioxide and water. As described above, a plastic having a high oxygen content including a low molecular weight aliphatic compound as a constituent component and oxygen molecules in the bond is essentially biodegradable. Therefore, the biodegradable plastic preferably used in the present invention is a plastic having a low oxygen content and a high oxygen content including a low molecular weight aliphatic compound as a constituent component.

  Aliphatic polyesters have greatly different physical properties depending on their constituent molecules. Table 2 shows the thermal and mechanical properties of typical aliphatic polyesters.

  In general, aliphatic polyesters have a low melting point, and this may be due to the fact that ester bonds are low in polarity and do not have functional groups in the side chains, so that the intermolecular interaction is weak. However, PCL, PBS, PHB / V, and PLLA shown in Table 2 have higher melting points than room temperature. The aliphatic polyester shown here has high water resistance and moldability, and is highly practical. In particular, only PLLA (poly L-lactic acid) has a glass transition point at room temperature or higher and is in a glass state at room temperature, and therefore has higher strength and transparency than other plastics. Other aliphatic polyesters exhibit physical properties similar to those of polyethylene, polypropylene, and the like, whereas PLLA is close to physical properties such as polystyrene and polyethylene terephthalate (PET). From this point of view, PLLA is an important biodegradable plastic for applications that require a wide range of physical properties such as biodegradable eel nursery sheets.

  Therefore, specific examples of the biodegradable plastic preferable in the present invention are poly L-lactic acid, polyhydroxybutyrate / valerate, poly (ε-caprolactam), polybutylene succinate, and among them, poly L-lactic acid is the most. preferable.

  Next, the basic physical properties of PLLA are shown in Table 3 in comparison with other plastics.

  As is clear from Table 3, PLLA is a material that has high strength and elastic modulus in both tensile and bending and small elongation compared to polyethylene (LDPE, HDPE) and polypropylene (PP). It turns out that it is a physical property. However, the impact strength is low and the softening point is relatively low at 60 ° C. There is a drawing process as a method for improving these defects. PLLA has high crystallinity and can be oriented and crystallized by stretching. Oriented and crystallized PLLA maintains transparency, the softening point is near the melting point, and the strength increases by about 3 times compared to the case of unstretched.

Next, the fiber processability of PLLA will be described. PLLA is capable of high-speed melt spinning, and filaments (multi- and monofilaments), staples and molded products thereof have already been manufactured. The tensile strength of PLLA fiber is about 5 g / d, comparable to that of synthetic fibers such as PET and nylon, and has excellent heat resistance. In addition, PLLA fibers have a low elastic modulus and a supple texture compared to conventional polyester fibers. This is because an aromatic component is not included in the molecular chain. Therefore, it can be processed into dyed, spun yarn, woven fabric, non-woven fabric, and the like in the same manner as ordinary fibers. In particular, the nonwoven fabric is expected to be applied in the fields of agriculture and civil engineering materials. In soil and water, was observed strength reduction at several months, it shows a gradual decomposition behavior compared to natural fibers such as rayon. Thus, the polylactic acid fiber is a fiber that combines the spinnability and processability of synthetic fibers and the biodegradability of natural fibers. From such a point, the biodegradable plastic fiber most preferably used in the present invention is a polylactic acid fiber.

  Next, hydrolysis of PLLA in seawater will be described. The ester bond constituting PLLA is cleaved by a hydrolysis reaction, but hydrolysis in water decreases the molecular weight and mass within several percent within 30 days at pH 7.0 and 37 ° C. As the temperature increases, the hydrolysis reaction proceeds and the molecular weight becomes 10% or less.

From the above results, the following can be concluded as a conclusion.
The biodegradable plastic preferably used in the present invention is a plastic having a high oxygen content and containing a low molecular weight aliphatic compound as a constituent component and oxygen molecules in the bond.

  The more preferred biodegradable plastic used in the present invention is an aliphatic system having a hydrolyzable group containing an oxygen atom such as ester, carbonate, ether, amide, urethane, etc., and having a structural unit of 6 or less carbon atoms. The oxygen content is high and the O / C ratio is in the range of 0.3 to 1.0.

  Specific examples of more preferred biodegradable plastics for use in the present invention are poly L-lactic acid, polyhydroxybutyrate / valerate, poly (ε-caprolactam), polybutylene succinate.

  A specific example of the most preferred biodegradable plastic for use in the present invention is poly L-lactic acid.

The present invention uses a blended fiber of biodegradable plastic fibers and biodegradable natural cellulose fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized, and degradation intermediates are degraded in the metabolic pathways of organisms. To do. This makes it possible to utilize the hydrophilic characteristics of natural fibers, improve molding processability, have flexibility, and to form an ammo nursery sheet that is flexible and has good adhesion to the sea bottom in the inner bay shallow water area, and reduces manufacturing costs. Can be reduced.

Biodegradable natural cellulose fibers that are hydrolyzed or enzymatically oxidized by enzymes in the environment used in the present invention, and degradation intermediates are degraded in the metabolic pathways of organisms include cotton, Bombax cotton, and Kapok. Illustrative seed hair fibers, hemp, flax, burlap, ramie, mulberry, mitsumata and other gin skin fibers, Manila hemp, New Zealand hemp and other leaf fibers, coniferous trees, hardwood fibers, bamboo fibers and the like.

The biodegradable eel seedling sheet of the present invention is biodegradable plastic fiber and biodegradable natural cellulose, which are hydrolyzed by enzymes in the environment or enzymatically oxidized, and degradation intermediates are degraded in the metabolic pathway of the organism. the blended fibers of the fiber a sheet formed by intertwined at random, as the fiber is the thickness from 1 to 30 Desi te box, a length 20 to 80 mm,. 5 to a thickness has flexibility 40 mm, porosity is 90% or more, and the internal space forms a surface seawater conduit.

At this time, the blending ratio of the biodegradable natural cellulose fiber is preferably 5 to 30 wt%, and more preferably 10 to 20 wt%. When the blending ratio of the biodegradable natural cellulose fiber exceeds 30 wt%, the intended function of preventing erosion cannot be obtained, and further, it becomes a factor for inhibiting the expansion of rhizomes of eelgrass due to increased entanglement due to fiber wetting. On the other hand, when the blending ratio is less than 5 wt%, adhesion at the sea bottom due to the flexibility of the sheet-like body cannot be obtained.

The present invention relates to a woven fabric of blended fibers of biodegradable plastic fibers and biodegradable natural cellulose fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized, and degradation intermediates are degraded in the metabolic pathways of organisms. To plant seedlings of eel on a sheet made of cloth, non-woven fabric, or woven fabric, cultivate and cultivate for a period of time in an onshore simulated sea in an aquarium, and grow a strong eel seedling that can be transplanted to the seabed in the inner bay shallow water It is a summary. In the following, the seedling and breeding conditions of sea cucumber on land will be described.

In the present specification, “terrestrial simulated sea in aquarium” means biodegradable plastic fibers and biodegradable products that are hydrolyzed by enzymes in the environment or enzymatically oxidized, and degradation intermediates are degraded in the metabolic pathways of organisms. It means a water tank in which a sheet made of woven fabric, non-woven fabric or woven fabric made of a blended fiber with degradable natural cellulose fibers is laid in a water tank, seeds of sea lions are sown, and seawater is continuously poured in a microflow state.

In practicing the present invention, the relationship between seeding depth and budding when seeds of sea cucumber are sown on a woven fabric, a nonwoven fabric or a woven fabric made of a mixed fiber of biodegradable plastic fiber and biodegradable natural cellulose fiber. is important. Amamo seeds have a Wentworth particle size category φ scale of 1-2 and a medium sand size of 0.25-0.5 mm, and the seeds emerged up to 60 mm of covering soil, that is, the buds appeared on the bottom of the sea. It is said that no budding occurs at 90-100 mm or more.

A sheet of woven fabric, non-woven fabric or fabric made of biodegradable plastic fiber that is hydrolyzed or enzymatically oxidized by an enzyme in the environment used in the present invention, and the degradation intermediate is degraded in the metabolic pathway of the organism . The degree of opening (opening) can be freely set as desired, but when the opening diameter is set to 0.25 to 0.5 mm and the thickness of the sheet is 5 to 40 mm, the deepest part Even if eel seeds are sown in 40 mm, they germinate completely. If the thickness of the sheet is 5 mm or less, it may be moved by a tidal current or the like due to its light weight, and if it is 40 mm or more, unnecessary costs are incurred.

The present invention is made of a blended fiber of biodegradable plastic fibers and biodegradable natural cellulose fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized, and degradation intermediates are degraded in the metabolic pathways of organisms . A sheet of woven fabric, non-woven fabric, or woven fabric is sown with eelgrass seeds and cultured and grown in a simulated sea on land for a certain period of time. Water temperature management at this time has a great influence on flower branch formation.

  The flower branch formation rate of eelgrass varies depending on the growth environment. When eelgrasses form flower branches, the shoots that have become flower branches die, and the number of eelgrass strains drastically decreases after the flower branch formation period. Therefore, it is preferable to set the water temperature so as to suppress the formation of flower branches in order to prevent the flower branch formation phenomenon of sea cucumber.

  The water temperature is not set uniformly, but onshore simulated underwater tests using water tanks are carried out using seeds collected from the sea eels that are gathering in the shallow waters of the inner bay, where rehabilitation, creation and maintenance of the eelgrass field are planned. It is necessary to go and set the water temperature to suppress flower branch formation. For example, in the case of eelgrass in the shallow water area of Ouchiyama Bay in Okayama Prefecture, the rate of flower branch formation was 80% at natural water temperature in July, but it was reported that it decreased to 7% at 20 ° C. There is. In addition, in the case of eelgrass in Odawara Bay, Kanagawa Prefecture, it has been reported that flower branch formation was suppressed by raising the temperature by + 3 ° C (minimum water temperature of 15 ° C) in winter. Therefore, in order to suppress the formation of flower branch of sea cucumber, it is preferable to adjust the water temperature according to the environment of the sea cucumber algae where the sea eel seeds are collected, but if the water temperature is adjusted to 15 ° C. or more from summer to winter, It is presumed that formation can be suppressed.

  Hereinafter, the present invention will be described specifically by way of examples.

[Example 1]
Unitika fiber, which is a polylactic acid fiber as a biodegradable plastic fiber that is hydrolyzed or enzymatically oxidized by enzymes in the environment according to the specifications shown in Table 4 and the degradation intermediates are degraded in the metabolic pathways of organisms. “Terramac” (registered trademark) manufactured by Co., Ltd. and bamboo fiber were formed into a sheet by a thermal bonding method.
The seeds collected from perennial natural eelgrass beds in the shallow sea water off the Katakami Port off the coast of Bizen City, Okayama Prefecture were used as the eelgrass seeds.
50 seeds of sea eel seeds were sown on the biodegradable sea cucumber sheet shown in Table 4 in a water tank where the onshore simulated underwater test was performed, and cultured and grown under the following conditions.
Biodegradable amamo sheet: 100 x 100 (mm)
Reinforcement net: Jute net Growth conditions: Water temperature 10 ° C, 5,000 lx
Soil cover: 30% bark compost sand

[Example 2]
Using the same biodegradable eelgrass sheet as in Example 1, eelgrass seeds were sown on the lower side of the sheet (on the bottom of the test water tank). The growth conditions were the same as in Example 1.

Comparative example

  Without using biodegradable eelgrass sheets, eelgrass seeds were sown directly.

  The germination and growth status of sea cucumber seeds sown in Example 1 and Example 2 was observed, and the results are shown in Tables 5 and 6.

  Using the biodegradable eelgrass sheets obtained in Example 1 and Example 2 (90 days after sowing), a runoff test of eelgrass seedlings under a horizontal flow load was performed. The results are shown in Table 7.

  About the biodegradable amamo sheet shown in Examples 1 and 2, a sheet of a practical size was made as a trial, and a sandy and mud-like mixture of silt and mud having a water depth of 1.5 to 2.0 m in Bikata City, Okayama Prefecture A transplant test was carried out by laying in line with the unevenness of the bottom of the seabed.

Biodegradable amamosheets with the following specifications were used in the field transplantation test. In addition, the growth conditions of the sea cucumber seedlings in the water tank after sowing were the same as in Examples 1 and 2.
Biodegradable amamo sheet: 500 x 500 (mm)
Reinforcement net: Jute net Amamo seedling: 1,500-1,600 trees / m ² , maximum leaf length 80-200mm

  Table 8 shows the results of the on-site transplantation test. In addition, 5 biodegradable sheets were transplanted each and fixed to the seabed with 200 mm bamboo skewers.

Example 3
In Example 3, in June 2004, 50 eel seeds collected from a natural eelgrass bed at a depth of 1.5m off the coast of Kotsubo, Isogo City, Kanagawa Prefecture, were used in the same reinforcement net (jutenet) as in Example 1. The seeds were sown on a reinforced biodegradable amamo sheet (100 × 100 (mm)), covered with sand mixed with 30% bark compost, and cultured and grown at a minimum water temperature of 20 ° C. or more and 5,000 lx.

  Observation of the growth state 30 days after sowing revealed that the formation rate of flower branches was 10%, the appearance rate of hypocotyls was 90%, and the appearance rate of cotyledons was 92%. The maximum leaf length on the 90th day after sowing was 140 mm, and the average number of leaves was 6. Thereafter, the cells were further cultured to produce 5 biodegradable eel seedling sheets in which 1,500 to 1,600 eel seedlings having a maximum leaf length of 80 to 200 mm were cultivated per square meter.

  This biodegradable eel seedling sheet was fitted to the bottom of the bottom of five seabeds consisting of fine sand and mud of natural eelgrass beds at a depth of 1-2m off the coast of Kotsubo, Choshi City, Kanagawa Prefecture, from May to June 2006 And fixed with a 200 mm bamboo skewer. As a result of observation one year after transplantation, the average survival rate of sea cucumber seedlings was 98%, and the maximum leaf length was 670 ± 80 mm.

Example 4
In Example 4, biodegradability obtained by reinforcing 50 seeds of sea cucumber seeds collected from a natural seagrass algae offshore in Wakasa Bay, Fukui Prefecture in February 2004 with the same reinforcing net (jute net) as in Example 1. An amamo sheet (100 × 100 (mm)) was sown, covered with 30% bark compost sand, and cultivated and grown at a minimum water temperature of 19 ° C. or more and 5,000 lx.

  Observation of the growth state 30 days after sowing revealed that the formation rate of flower branches was 10%, the appearance rate of hypocotyls was 90%, and the appearance rate of cotyledons was 92%. The maximum leaf length on the 90th day after sowing was 140 mm, and the average number of leaves was 6. Thereafter, the cells were further cultured to produce 5 biodegradable eel seedling sheets in which 1,500 to 1,600 eel seedlings having a maximum leaf length of 80 to 200 mm were cultivated per square meter.

This biodegradable seagrass nursery sheet, Fukui Prefecture Wakasa Bay offshore water depth of 1m over the March to June 2006, laid in accordance with the non-land of the bottom surface of the seabed five locations consisting of mud and fine sand, bamboo skewer of 200mm Fixed with. As a result of observation one year after transplantation, the average survival rate of sea cucumber seedlings was 98%, and the maximum leaf length was 650 ± 90 mm.

Example 5
In Example 5, seeds of core duck (Zostera japonica. Et Graebn.) Collected from a natural core duck algae field at a depth of 70 cm off the Akkeshi coast in Hokkaido in August 2004 were used. A biodegradable amamo sheet reinforced with the same reinforcing net (jute net) as in Example 1 was used to produce a biodegradable sheet having a size of 500 × 500 mm for practical use tests. This sheet is seeded with 50 eel seeds, covered with sand mixed with 30% bark compost, cultivated and grown under 5,000 lx culture and growth conditions with a minimum water temperature of 19 ° C or higher, and a maximum leaf length of 80 to 200 mm. Five biodegradable eel seedling sheets were produced by cultivating 1,500 to 1,600 eel grown seedlings per square meter.

From May to June 2006, this biodegradable eel seedling sheet was laid on the bottom of the bottom of five seabeds consisting of fine sand 70cm deep off the Akkeshi coast of Hokkaido and fixed with 200mm bamboo skewers. . As a result of observation one year after transplantation, the average survival rate of the eelgrass seedlings was 98%, and the maximum leaf length was 675 ± 80 mm.

Example 6
In Example 6, shrimp seeds (Phyllospadix japonicus Makino) collected from a natural shrimp seaweed algae at a depth of 5 to 8 m off the coast of Kominato in Chiba Prefecture in March 2004 were used. A biodegradable amamo sheet reinforced with the same reinforcing net (jute net) as in Example 1 was used to produce a biodegradable sheet having a size of 500 × 500 mm for practical use tests. This sheet is seeded with 50 amamo seeds, covered with sand mixed with 30% bark compost, cultured and grown under the culture and growth conditions of a minimum water temperature of 18 ° C and 5,000 lx, and the maximum leaf length grows to 80-200 mm. Five biodegradable eel seedling sheets were produced by cultivating 1,500 to 1,600 eel seedlings per square meter.

The biodegradable seagrass nursery sheet, laid in accordance with the non-land of the bottom surface of the mixed sand muddy seabed five locations in Chiba Prefecture Kominato-cho Kominato coast offshore water depth 5~8m of silt and mud, bamboo skewer of 200mm Fixed with. As a result of observation one year after transplantation, the average survival rate of sea cucumber seedlings was 97%, and the maximum leaf length was 665 ± 90 mm.

[Examples 7 to 11]
"Teramac" (manufactured by Unitika Fiber Co., Ltd.), which is a polylactic acid fiber, is a biodegradable plastic fiber that is hydrolyzed by enzymes in the environment or is enzymatically oxidized and the degradation intermediates are degraded in the metabolic pathways of organisms. 5% (Example 7), 10% (Example 8), 15% (Example 9), 20% (Example 10) and 30% (Example) 11) was formed into a sheet of 500 mm (length) × 500 mm (width) × 30 mm (thickness) by a thermal bonding method to obtain an amamo sheet.

The seeds collected from perennial natural eelgrass beds in the shallow sea water off the Katakami Port off the coast of Bizen City, Okayama Prefecture were used as the eelgrass seeds.
50 seeds of sea cucumber seeds are sown on the above sea bream sheet in the water tank for the onshore simulated underwater test, covered with 30% bark compost sand, and continuously poured in seawater with a minimum temperature of 20 ° C. Cultured and cultivated in an aquarium.

  Observation of the growth state 30 days after sowing revealed that the formation rate of flower branches was 10%, the appearance rate of hypocotyls was 90%, and the appearance rate of cotyledons was 92%. The maximum leaf length on the 90th day after sowing was 140 mm, and the average number of leaves was 6. Thereafter, the cells were further cultured to produce 5 biodegradable eel seedling sheets in which 1,500 to 1,600 eel seedlings having a maximum leaf length of 80 to 200 mm were cultivated per square meter.

  This eelgrass seedling sheet was laid on a shallow seabed with a depth of 1.5-2.0m off the coast of Katakami Port, Bizen City, Okayama Prefecture, where the seeds of eelgrass were collected, and a minimum of 20mm, and a maximum of 100mm inland. Fixed. One year later, the sea cucumber seedling sheet was lifted from the sea floor and observed for followability to the sea floor. As a result, all eel nursery sheets followed the bottom of the seabed, and the roots of the eel were growing and growing in the seabed. In particular, 10% (Example 8), 15% (Example 9) and 20% (Example 10) completely follow the uneven surface of the seabed, and the rhizomes of the eelgrass are in the seabed. The sea bottom and the seat were integrated, and it took considerable power to lift the seat by hand. From this test result, it was confirmed that the ammo nursery sheet produced by blending 5-30% bamboo fiber with biodegradable plastic fiber has excellent followability to the sea floor. In particular, it was confirmed that the blend ratio of bamboo fibers is preferably 10 to 20%.

[Comparative Example 1]
"Teramac" (manufactured by Unitika Fiber Co., Ltd.), which is a polylactic acid fiber, is a biodegradable plastic fiber that is hydrolyzed by enzymes in the environment or is enzymatically oxidized and the degradation intermediates are degraded in the metabolic pathways of organisms. A blended fiber containing 96% of registered trademark and 4% of bamboo fiber was molded into a sheet of 500 mm (length) × 500 mm (width) × 30 mm (thickness) by a thermal bonding method to form five amamo sheets. When the manufactured amamo sheet was rubbed by hand, a slightly inflexible feel was obtained.

Furthermore, in the same procedure as in Examples 7 to 11, an ammo nursery sheet was produced, and laid on the same sea bottom as that in Examples 7 to 11, and observed to follow the sea bottom. As a result, all of the five sheets were lifted completely from the bottom of the seabed, and the rhizomes of the eel were exposed and some were dead. This is due to the low blending ratio of bamboo fibers to polylactic acid fibers, which are biodegradable fibers that are hydrolyzed by enzymes in the environment or are oxidized by enzymes and the degradation intermediates are degraded in the metabolic pathways of organisms. It is presumed that the overall sheet lacks flexibility.

By referring to Examples 7-11 and Comparative Example 1, for biodegradable plastic fibers that are hydrolyzed or enzymatically oxidized by enzymes in the environment and the degradation intermediates are degraded in the metabolic pathway of the organism. Amamo nursery sheet using a sheet produced by blending 5-30% natural fiber is superior in flexibility compared to 100% biodegradable plastic fiber or less than 5% natural fiber, 10cm It is understood that the above sea level unevenness with the above height difference can be followed sufficiently.

[Examples 12 to 16]
Examples 12-16 are 5-30% natural fiber relative to biodegradable plastic fibers that are hydrolyzed or enzymatically oxidized by enzymes in the environment and degradation intermediates are degraded in the metabolic pathways of the organism. This is a penetrating test for the root of rhesus root when blended.
In the same manner as in Examples 7 to 11, polylactic acid fibers are used as biodegradable plastic fibers that are hydrolyzed by enzymes in the environment or are oxidized and degradable intermediates are degraded in the metabolic pathways of organisms. 5% (Example 12), 10% (Example 13), 15% (Example 14), 20% (Examples) of bamboo fiber with respect to “Terramac” (registered trademark) manufactured by Unitika Fiber Co., Ltd. 15) and 30% (Example 16) were blended to produce 5 sheets each of 500 mm (length) × 500 (width) × 30 mm (thickness).

  Sea bream seeds collected from a perennial natural eelgrass bed in the shallow sea area off the coast of Katakami Port, Bizen City, Okayama Prefecture, on the above eelgrass sheet in a water tank for onshore simulated underwater testing The grains were sown, covered with sand mixed with 30% bark compost, and cultured and cultivated in a water tank in which seawater having a minimum temperature of 20 ° C. was constantly poured in a fine flow state.

  When the growth state of the amphix rhizome 60 days after sowing was observed, it was confirmed that the amphix rhizome penetrated from all the amamo sheets. The flower branch formation rate was 10%, the hypocotyl appearance rate was 90%, and the cotyledon appearance rate was 92%. The maximum leaf length on the 90th day after sowing was 140 mm, and the average number of leaves was 6.

[Comparative Example 2]
Manufactured 5 amamo sheets with a natural fiber blend ratio of 31% for biodegradable plastic fibers that are hydrolyzed by enzymes in the environment or oxidized and degraded by biological metabolic pathways. The same procedure as in Examples 7 to 11 was repeated except that. Sea bream seeds collected from a perennial natural eelgrass bed in the shallow sea area off the coast of Katakami Port, Bizen City, Okayama Prefecture, on the above eelgrass sheet in a water tank for onshore simulated underwater testing The grains were sown, covered with sand mixed with 30% bark compost, and cultured and cultivated in a water tank in which seawater having a minimum temperature of 20 ° C. was constantly poured in a fine flow state.

  When the growth state of the amphix rhizome 60 days after sowing was observed, it was confirmed that the amphix rhizome was not penetrated from all the amamo sheets. The flower branch formation rate was 50%, the hypocotyl appearance rate was 70%, and the cotyledon appearance rate was 70%. The maximum leaf length on the 90th day after sowing was 100 mm, and the average number of leaves was 4.

From Comparative Example 2, when the blend ratio of natural fibers to biodegradable plastic fibers that are hydrolyzed or enzymatically oxidized by enzymes in the environment and decomposed by biological metabolic pathways is 31% or more It is presumed that natural fibers absorb a large amount of seawater and swell, the fibers adhere to each other, the resistance of the web layer increases, and the penetration inhibition of the amphix roots occurs. Furthermore, the fact that the rhizomes do not penetrate the sea cucumber seedling sheet indicates that the growth of the sea eel above the seed bed, i.e. It was confirmed that it had an adverse effect on growth.

The biodegradable eel nursery sheet of the present invention has industrial applicability exemplified below.
1. Implantable in sheets of blended fibers of biodegradable plastic fibers and biodegradable natural cellulose fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized and degradation intermediates are degraded in the metabolic pathways of the organism Since the seedlings of strong eel grown in various sizes are embraced, they can be transferred as biodegradable eel seedling sheets and are subject to commercial transactions like rice seedlings. Contributes not only to the fields but also to primary industries such as agriculture and fisheries.

2. Implantable in sheets of blended fibers of biodegradable plastic fibers and biodegradable natural cellulose fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized and degradation intermediates are degraded in the metabolic pathways of the organism Since the seedlings of strong eelgrass that have grown to a certain size are embraced, simply laying them on the seabed in the shallow waters of the inner bay ensures that the eelgrass seedlings will not be lost due to tides etc. Since it can contribute to restoration, creation and maintenance, it can reduce the labor force of underwater work, which is inherently difficult to maintain, and can greatly reduce the total cost, contributing to industries such as the offshore construction field.

3. A blend of biodegradable plastic fibers and biodegradable natural cellulose fibers, in which the base of the sea cucumber nursery sheet is hydrolyzed or enzymatically oxidized by enzymes in the environment and degradation intermediates are degraded in the metabolic pathways of the organism Because it is a fiber sheet, it will break down in the sea over time and will not adversely affect the marine tourism industry as it will not degrade the marine environment.

4). The whole biodegradable sea eel seedling sheet is flat and flexible, and has no rigid body, so it is about 1.5km from the sandy beach, shallow water in the inner bay about 50cm to 10m, marine sports such as swimming and scuba diving, seafood Even if it is laid in the eelgrass algae pond that overlaps with other fishing grounds, it will not harm people, so it will not adversely affect other industrial fields such as marine tourism and fisheries.

5. It contributes to the expansion of a new use as a marine material of biodegradable plastics, which are hydrolyzed by enzymes in the environment or oxidized, and degradation intermediates are degraded in the metabolic pathways of organisms .

Claims (6)

Woven fabrics and non-woven fabrics composed of biodegradable plastic fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized, and the degradation intermediates are degraded in the metabolic pathways of living organisms, and blended fibers of biodegradable natural cellulose fibers Or a sheet of woven fabric and seedlings of seedlings seeded on the sheet, cultured and grown for a period of time in a simulated sea in an onshore aquarium, and grown to a size that can be transplanted to the seabed in the inner bay shallow water A biodegradable mallard nursery sheet. The biodegradable eel seedling sheet has a thickness of 1 to 30 dtex and a length of 20 to 80 mm , and is hydrolyzed or enzymatically oxidized by an enzyme in the environment, and the degradation intermediate is a metabolic pathway of the organism. The thickness is 5 to 40 mm, the porosity is 90% or more, and the internal space is in the plane direction, formed by randomly entangled blended fibers of biodegradable plastic fiber and biodegradable natural cellulose fiber The biodegradable eel nursery bed sheet according to claim 1, wherein a seawater conduit is formed. The blend ratio of the biodegradable natural cellulose fiber to the biodegradable plastic fiber that is hydrolyzed by the enzyme in the environment or is enzymatically oxidized and the degradation intermediate is degraded in the metabolic pathway of the organism is 5 to 30% by mass The biodegradable eel nursery sheet according to claim 1 or 2. Biodegradable plastic fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized, and degradation intermediates are degraded in the metabolic pathways of living organisms , oxygen atoms such as esters, carbonates, ethers, amides, urethanes, etc. The hydrolyzable group is contained, the structural unit is an aliphatic system having 6 or less carbon atoms, the oxygen content is large, and the O / C ratio is in the range of 0.3 to 1.0. The biodegradable eel nursery sheet described in Izuka 1. Biodegradable plastic fibers that are hydrolyzed by enzymes in the environment or enzymatically oxidized and degradation intermediates are degraded in the metabolic pathways of organisms are poly L-lactic acid, polyhydroxybutyrate / valerate, poly ( The biodegradable eel nursery sheet according to any one of claims 1 to 4, which is at least one selected from the group consisting of (ε-caprolactam) and polybutylene succinate . The biodegradable eel nursery sheet according to any one of claims 1 to 5 is made to follow the shape of the surface of the seabed for repair, creation and maintenance of the sea bream field in the shallow water area of the inner bay with a water depth of about 5 cm to 10 m. A method for restoration, creation and maintenance of amamo fields, including laying and fixing with natural material fasteners.