JP6376493B2 - Aquatic organism growth methods - Google Patents

Description

  The present invention relates to a method for growing aquatic organisms.

  Since water exchange is poor in closed water areas, it is strongly affected by land loads, and sediment with high organic matter content accumulates and tends to be reduced. In such a reducing environment, the generation of hydrogen sulfide is promoted. Hydrogen sulfide is extremely toxic to living organisms, which reduces the number of living organisms and can be nearly inanimate. It is extremely important from the viewpoint of enhancing biodiversity and bioproductivity to reduce the hydrogen sulfide in the bottom mud and restore the good sediment environment and restore the living organisms.

  Civil engineering methods such as tillage, aeration, dredging and sand cover have been implemented as methods for improving sediment quality. However, these methods have secondary problems such as the diffusion of pollutants and the treatment of sludge after dredging, and problems such as high costs.

  Steel slag (for example, Patent Documents 1 and 2), coal ash granulated material (for example, Patent Documents 3 and 4), etc. are effective in reducing hydrogen sulfide generated in sediment with a high organic matter content. It is known that the former is redoxed by iron, and the latter is redoxed by manganese.

  In addition, there are fertilizers that elute iron as a fertilizer when the water quality is poor nutrition. For example, it contains iron, charcoal, and shochu or citrus koji, and iron ions are eluted by contact with iron and charcoal. In addition, an iron chelate generating material that generates iron chelate with a chelate substance contained in iron ions and shochu or citrus koji is known (Patent Document 5).

JP 2009-291668 A JP-A-2005-320230 JP 2012-22373 A JP 2008-121263 A JP 2010-242075 A

  In the iron chelate generating material of Patent Document 5, the elution amount of iron ions is not sufficient, and there is still room for improvement. Moreover, it contains shochu or citrus koji, and these are organic substances themselves, and their addition increases the organic substance content, which may further deteriorate the reducing state.

  The present invention has been made in view of the above-mentioned matters, and the object of the present invention is to prepare an environment capable of promoting the growth of aquatic organisms without causing deterioration of the reductive state due to an increase in the content of organic matter. The object is to provide a method of growing the above.

The aquatic organism propagation method according to the present invention comprises:
A fertilizer containing coal ash, iron and a chelating agent , wherein the blending ratio of the coal ash and the iron is 3: 7 to 7: 3 in a weight ratio, is placed in a shellfish or algae breeding water area,
Promote the growth of the shellfish or the algae,
It is characterized by that.

  Moreover, it is desirable to use the fertilizer in which the chelating agent is citric acid.

  Moreover, it is desirable to use the fertilizer containing 3% by weight or more and 7% by weight or less of the citric acid.

Also, eluting iron ions, manganese ions and zinc ions in water, forming iron chelate, manganese chelate and zinc chelate with the chelating agent, and using the fertilizer to elute nitrogen, phosphorus and silicon,
It is desirable to dissolve metal ions as a complex from the fertilizer and to elute nitrogen, phosphorus, and silicon so that the shellfish or the algae ingest them directly or indirectly.

  Moreover, you may promote the growth of clams or oysters as the shellfish.

  In the method for aquatic organism propagation according to the present invention, a fertilizer in which the amount of elution of metal ions is high and the generated metal ions form a complex with a chelating agent and dissolved therein is placed in the breeding water area of shellfish or algae. The growth of aquatic organisms can be promoted without incurring a reductive deterioration due to an increase in organic matter content.

3 is a graph showing hydrogen sulfide concentrations of Samples 1 to 3 in Experiment 1. 6 is a graph showing the hydrogen sulfide concentration of Samples 4 to 6 in Experiment 1. 6 is a graph showing Fe concentrations of Samples 1 to 3 in Experiment 1. 4 is a graph showing Mn concentrations of Samples 1 to 3 in Experiment 1. 4 is a graph showing Zn concentrations of Samples 1 to 3 in Experiment 1. 6 is a graph showing Fe concentrations of Samples 4 to 6 in Experiment 1. 6 is a graph showing Mn concentrations of Samples 4 to 6 in Experiment 1. 6 is a graph showing Zn concentrations of Samples 4 to 6 in Experiment 1. 6 is a graph showing Fe concentrations of Samples 11 to 16 in Experiment 2. 10 is a graph showing hydrogen sulfide concentrations of samples 21 to 23 in Experiment 3. FIG. 10 is a graph showing Fe concentrations of Samples 21 to 23 in Experiment 3. 10 is a graph showing Zn concentrations of Samples 21 to 23 in Experiment 3. 10 is a graph showing Mn concentrations of Samples 21 to 23 in Experiment 3. 7 is a graph showing hydrogen sulfide concentrations of samples 31 to 37 in Experiment 4. It is a graph which shows Fe concentration of samples 31-37 in experiment 4. FIG. It is a graph which shows the Zn density | concentration of the samples 31-37 in the experiment 4. FIG. It is a graph which shows Mn density | concentration of the samples 31-37 in the experiment 4. FIG. Is a graph showing the _NO 3 + NO ₂ concentration of the sample 31 to 37 in the experiment 4. 7 is a graph showing NO ₂ concentrations of samples 31 to 37 in Experiment 4. 10 is a graph showing NH ₄ concentrations of Samples 31 to 37 in Experiment 4. 10 is a graph showing PO ₄ concentrations of samples 31 to 37 in Experiment 4. Is a graph showing a SiO ₂ concentration of the sample 31 to 37 in the experiment 4. 10 is a graph showing the hydrogen sulfide concentration in Experiment 5. 10 is a graph showing the Fe concentration in Experiment 5. 10 is a graph showing Zn concentration in Experiment 5. 10 is a graph showing the Mn concentration in Experiment 5. S. It is a graph which shows the result of the proliferation test of costatum. N. It is a graph which shows the result of the proliferation test of Pellucida. It is a graph which shows the collection result of a clam. It is a graph which shows the result of POC and AVS. 31 (A) and 31 (B) are diagrams illustrating the installation status of the sample 34 on the oyster bowl. It is a figure explaining the position of a 300g addition group, a 100g addition group, and a control group.

  The aquatic organism propagation method according to the present embodiment is performed by arranging a fertilizer described later in a breeding water area of shellfish or algae. The arrangement of the fertilizer can be carried out by various methods such as spraying in the water area where breeding is carried out, placing the fertilizer in a net-like bag, and inserting into the bottom mud of the breeding water area.

  The fertilizer used contains coal ash, iron and a chelating agent, and elutes iron ions, manganese ions and zinc ions in water in a chelate state at a high concentration. Also, nitrogen, phosphorus and silicon are eluted from the coal ash. Metal ions are eluted from the fertilizer to dissolve the metal ions as a complex, and nitrogen, phosphorus and silicon are eluted. Iron, manganese, zinc, nitrogen, phosphorus, and the like are essential nutrient sources essential for the growth of shellfish and algae.

  As described above, since the fertilizer can elute various metal ions and can be dissolved in water as a complex in an ionic state, these can be directly or indirectly taken up by shellfish and algae. Thereby, growth of shellfish and algae can be promoted. Examples of shellfish include oysters, clams and swordfish. Examples of algae include useful algae (edible algae) such as seaweed, young cloth, and kelp, and floating microalgae and attached microalgae that serve as food for shellfish.

  In addition, shellfish such as oysters, clams and swordfish are characterized by a high zinc content in the meat as a health ingredient. Zinc is an essential nutrient for humans and difficult to take. If shellfish with high zinc content can be produced, zinc intake by humans can be increased accordingly. Zinc becomes a metal salt in water and cannot be taken up by shellfish. However, in the fertilizer described above, zinc ions are eluted, and zinc ions are dissolved as a complex by the chelating agent. Thereby, since shellfish can be taken in into the flesh of shellfish by ingestion directly by intake of zinc ion or ingestion of phytoplankton which ingested zinc ion, the commercial value of shellfish can be raised.

The fertilizer used is obtained from coal ash, iron and chelating agents. Coal ash is ash generated when coal is burned. Coal ash generally contains silica (SiO ₂ ) and alumina (Al ₂ O ₃ ) as main components, and also contains zinc, manganese, and the like as trace components. What is necessary is just to use what is produced in the thermal power plant which is generating electricity using coal as a raw material for coal ash. Coal ash generated in a thermal power plant is spherical fine particles that are scattered by a gas flow, and can be suitably used as it is. In addition, the coal ash generated in the thermal power plant contains nitrogen content because ammonia water is sprayed in the form of a mist when denitrating exhaust gas.

  As the iron, scrap iron or the like is used, and it is preferable to use substantially pure iron with impurities of 10% by weight or less, preferably 5% by weight or less, more preferably 99% by weight or less. Iron is preferably in powder form.

  The chelating agent promotes elution of iron ions from iron and elution of manganese ions and zinc ions from coal ash. Moreover, it forms a complex with the generated iron ion, manganese ion, and zinc ion to form iron chelate, manganese chelate, and zinc chelate. For this reason, each eluted metal ion can be dissolved in water in an ionic state. The chelating agent is not particularly limited as long as it can fulfill the above function, and citric acid is an example.

  The fertilizer mentioned above is obtained by mixing iron powder, coal ash, and a chelating agent and molding the mixture into a predetermined shape. The fertilizer may have any shape such as a spherical shape, a polygonal shape, a briquette shape, or the like. Various known methods can be used for the molding, and examples thereof include a method in which a raw material is put in a rotating drum and granulated to a predetermined size while adding a liquid such as water.

  The weight ratio of iron and coal ash is preferably 3: 7 to 7: 3, and more preferably 4: 6 to 6: 4.

  The mixing ratio of the chelating agent is preferably 3% by weight or more with respect to the total amount of iron and coal ash. In addition, if the compounding ratio of the chelating agent is increased, the elution amount of each metal ion increases, while the fertilizer to be molded tends to become brittle. For this reason, it is more preferable that the fertilizer contains 3 wt% or more and 7 wt% or less of the chelating agent from the viewpoint of the elution amount of the metal ions, the moldability of the fertilizer, and the shape maintainability.

  Further, in the fertilizer, nitrogen, phosphorus, silica and the like are eluted in addition to the above-described iron, manganese and zinc. These are eluted from the coal ash.

  Hereinafter, based on an Example, the fertilizer used for the proliferation experiment of the aquatic organism mentioned later is further demonstrated.

(Test material)
Coal ash having a particle size of 50 μm or less was used. Table 1 shows the composition of the coal ash used.

  Steel slag was used for comparison with iron powder. Table 2 shows the composition of the steel slag used.

  The iron powder manufactured by Hinomaru Sangyo Co., Ltd. was used with an Fe content of 99% and a particle size of 60 μm. As the carbon, high-purity pitch coke having a particle diameter of 1 mm or less was used. Citric acid was manufactured by Wako Pure Chemical Industries, Ltd. (food additive, crystalline).

(Sample production)
In each of the following experiments, the raw materials are mixed at the blending ratios described below, put into a drum granulator, and granulated by adding water little by little while rotating the granulator to produce a spherical sample with a diameter of about 1 cm. Used.

(Experiment 1)
The amount of iron ions eluted by iron powder and steel slag and the reduction effect of hydrogen sulfide were verified.

  Table 3 shows the mixing ratio of the raw materials of Samples 1 to 6 used in this experiment.

(Preparation of hydrogen sulfide solution)
1 L of ultrapure water (Milli-Q water) was put into a beaker, and the air was purged with nitrogen so that the dissolved oxygen concentration was 0.1 mg / L or less. To this was added Na ₂ S · 9H ₂ O (special reagent grade, manufactured by Nacalai Tesque) to a concentration of 0, 50, 100 mg-S / l, and 1M Tris-HCl (for molecular biology, as a pH buffering agent). 30 ml of Wako Pure Chemical Industries, Ltd.) was added to adjust the pH to 8.3 ± 0.1 to prepare a hydrogen sulfide solution. Hereinafter, they are referred to as H2S0, H2S50, and H2S100, respectively.

  After adding 0.2 g of sample to a glass vial for gas chromatography (150 ml, manufactured by Maruemu), put 100 ml of hydrogen sulfide solution, replace the gas phase in the bottle with nitrogen gas, rubber stopper and aluminum fittings And sealed. Thereafter, the vial was placed in MAGIC VAC (As One Co., Ltd., 20 × 30 cm, made of polyamide, nylon / polyethylene), sealed, and shaken for 7 days at 25 ° C. and 40 rpm.

  Seven days later, the concentration of hydrogen sulfide in the hydrogen sulfide solution was measured with a Kitagawa detector tube (manufactured by Komyo Chemical Co., Ltd., for 200 SA, 2-1000 ppm).

  Furthermore, an Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) analyzer (ICP-AES) analyzer was used for the filtrate obtained by filtering each hydrogen sulfide solution after 7 days with a 0.45 μm syringe filter (MERCK MILLIPORE, Millex-HN, nylon). -Elmer Co., Optima 7300 DV) was used to measure each concentration of eluted Fe, Mn, and Zn.

  FIG. 1 shows the measurement result of the hydrogen sulfide concentration in the hydrogen sulfide solution to which samples 1 to 3 are added, and FIG. 2 shows the measurement result of the hydrogen sulfide concentration in the hydrogen sulfide solution to which samples 4 to 6 are added. Moreover, the density | concentration of Fe, Mn, and Zn in the hydrogen sulfide solution which added the samples 1-3 is shown in FIG.3, FIG.4, FIG.5, respectively. Moreover, the density | concentration of Fe, Mn, and Zn in the hydrogen sulfide solution which added samples 4-6 is shown in FIG.6, FIG.7, FIG.8, respectively. Note that the same experiment was performed three times for each sample, the symbols in FIGS. 1 to 8 represent the average value, and the error bar represents the standard deviation. The same applies to Experiments 2 to 5 described later.

  In Samples 1 to 3 containing steel slag, hydrogen sulfide was reduced to some extent, but in Samples 4 to 6 containing iron, hydrogen sulfide was almost lost in both H2S50 and H2S100.

  The amount of iron elution is larger in Samples 4 to 6 containing iron powder than in Samples 1 to 3 containing steel slag. Moreover, about other Zn and Mn, the amount of elution of samples 4-6 is larger than samples 1-3. Since these are components not contained in the iron powder, they are eluted from the coal ash, and it is considered that the amount of elution increased due to the compatibility between the coal ash and iron.

  From these results, it was found that combining coal ash and iron is more appropriate than combining steel slag.

(Experiment 2)
Citric acid and carbon were used as auxiliary agents for promoting the elution of metal ions, and their effects were verified. Table 4 shows the mixing ratio of the raw materials of Samples 11 to 16 used in this experiment.

  Experiments were performed in the same manner as Experiment 1 using Samples 11 to 16 and the hydrogen sulfide solution H2SO. Then, as in Experiment 1, the Fe concentration in the hydrogen sulfide solution was measured. The measurement result of Fe concentration is shown in FIG.

  In the samples 12 and 13 containing carbon, the elution of iron was promoted compared to the sample 11 containing no carbon, but the iron elution amount increased by only 3.6% even when 30% by weight of carbon was added. Stayed in.

  On the other hand, in the case of adding citric acid, in the sample 14 added with 0.1% by weight, the elution amount of iron is increased by about 10% compared to the sample 11, and in the sample 16 added with 1.0% by weight, the iron is dissolved. Increased by about 28%. From this result, it was found that citric acid was much more effective than carbon in terms of elution of iron.

(Experiment 3)
The effect of the mixing ratio of iron powder and coal ash was verified. Table 5 shows the mixing ratio of the raw materials of Samples 21 to 23 used in this experiment.

  Experiments were performed in the same manner as Experiment 1 using Samples 21 to 23, respectively. Then, as in Experiment 1, the hydrogen sulfide concentration and the Fe, Zn, and Mn concentrations in the hydrogen sulfide solution were measured. The measurement results of the hydrogen sulfide concentration and the Fe, Zn, and Mn concentrations in the hydrogen sulfide solution are shown in FIGS. 10, 11, 12, and 13, respectively.

  In the test plot of H2S100, in samples 21 and 22, the hydrogen sulfide concentration decreased by about 50 ppm, and in sample 23, a decrease of about 30 ppm was observed, but in the test plot of H2S50, about 70 to 80 ppm for all samples. Decrease.

  Moreover, the amount of Fe elution was maximum in Sample 23 containing a large amount of coal ash, and about 5 ppm was observed. Further, Zn and Mn were also eluted in a large amount in the sample 23 containing a large amount of coal ash as in the case of Fe.

  From these results, the reduction ratio of hydrogen sulfide can be obtained at any ratio of coal ash and iron powder in the range of 3: 7 to 7: 3. In addition, in the sample 23 containing much coal ash, it is thought that the blending ratio of coal ash: iron powder is preferably 4: 6 to 6: 4 from the fact that collapse was observed and the elution amounts of Mn and Zn. .

(Experiment 4)
Then, it verified about the influence by the mixture ratio of a citric acid. Table 6 shows the mixing ratio of the raw materials of Samples 31 to 37 used in this experiment.

Experiments were performed in the same manner as Experiment 1 using Samples 31 to 37. Then, as in Experiment 1, the hydrogen sulfide concentration and the Fe, Zn, and Mn concentrations were measured. Furthermore, for those conducted with H2S0 _is determined _{NO 3 + NO 2 -N, NO} 2 -N, NH 4 -N, PO 4 -P, the _SiO 2 -Si auto analyzer (SWAAT, manufactured BLTEC Co.) Then, analysis was performed by Cu-Cd reduction method, naphthylethylenediamine method, indophenol method, molybdenum blue method, and molybdenum blue method, respectively.

The measurement results of the hydrogen sulfide concentration and the Fe, Zn, and Mn concentrations are shown in FIGS. 14, 15, 16, and 17, respectively. Further, the measurement results of the respective concentrations of NO ₃ + NO ₂ —N, NO ₂ —N, NH ₄ —N, PO ₄ —P, and SiO ₂ —Si are shown in FIG. 18, FIG. 19, FIG. 20, FIG. Shown in

  FIG. 14 shows that all samples show a tendency to reduce hydrogen sulfide, and that the higher the citric acid content, the higher the effect of reducing hydrogen sulfide. 15 to 17, it can be seen that the elution amounts of Fe, Zn, and Mn increase as the citric acid content increases. Note that Mn has no significant difference in concentration in each of the test groups of H2S0, H2S50, and H2S100, and that of Fe and Zn has a large difference between the concentration in H2S0 and the concentration in H2S50 and H2S100. It is considered that the reduction of the effect of elution of Fe and Zn is large. This is also shown in FIGS.

  Further, in the H2S50 test section, samples 34 to 37 containing citric acid at 3% by weight or more had a hydrogen sulfide concentration of almost 0, and therefore the fertilizer contains 3% by weight or more citric acid. preferable. Further, since the sample 37 containing 10% by weight of citric acid was brittle and easily collapsed, it is preferable that the content of citric acid in the fertilizer is 7% by weight or less from the viewpoint of formability and shape maintenance of the fertilizer. it is conceivable that.

From FIG. 18 to FIG. 22, the elution amounts of N, P, and Si also increase as the citric acid content increases. While N, P, and Si function as ecosystem nutrients, the eutrophic sediment promotes organic matter production, so it is better not to elute it excessively. However, even a large amount of NH ₄ eluted is a few tens of moles, which is not a concentration that promotes eutrophication. Further, in the sample 37 containing 10% by weight of citric acid, the molar concentration ratio of eluted N, P, Si, Fe is 20: 0.8: 16: 1, and compared with the red field ratio, Fe is 1000 times excess and other elements are almost equivalent. The red field ratio is the optimal elemental ratio for the growth of microalgae. The substance ratio in the organism and the substance ratio in the environmental water are almost the same, and the balance of substances related to production and decomposition is too short or large. It is a concept of the element ratio indicating a state where there is no. Thus, since the elution amounts of N, P, and Si are the same as the red field ratio, it is considered that there is no possibility of further worsening the eutrophic bottom sediment, and a large amount of Fe and the like are eluted to generate hydrogen sulfide. It can be said that it is suitable for the restoration of the health of the ecosystem in the water because it can supply nutrients by appropriately eluting N, P and Si while reducing the amount of water.

(Experiment 5)
Sample 34 in Experiment 4 (iron powder: 48.5% by weight, coal ash: 48.5% by weight, citric acid: 3% by weight) was used to verify the effect on seawater.

33 g of artificial seawater powder (Red Sea Salt, Red Sea Salt) was added to 1 L of ultrapure water to prepare 33 psu artificial seawater. Further, N ₂ gas was blown in to purge the air, and the dissolved oxygen concentration was reduced to 0.1 mg / l or less. To this was added Na ₂ S · 9H ₂ O to 0, 50, 100 mg-S / l to prepare a hydrogen sulfide solution. This hydrogen sulfide solution is referred to as Sa-H2S0, Sa-H2S50, and Sa-H2S100, respectively.

  100 ml of the above hydrogen sulfide solution was placed in a 150 ml vial. After 0.2 g of sample 34 was gently added thereto, it was sealed with a rubber stopper and an aluminum fitting. A 150 ml vial was placed in the MAGIC VAC, sealed with a sealing pack, shaken at 25 ° C. and 40 rpm for 7 days, and then the hydrogen sulfide concentration was measured with a detector tube. Furthermore, each density | concentration of Fe, Zn, and Mn was measured by ICP-AES about the filtrate filtered with the 0.45 micrometer syringe filter.

  FIG. 23 shows the measurement result of the hydrogen sulfide concentration in the hydrogen sulfide solution. The Fe, Zn, and Mn concentrations are shown in FIGS.

  Compared to the case of H2S0, H2S50, and H2S100 prepared with ultrapure water in Experiment 4, the elution of Fe, Zn, and Mn decreased, and the effect of reducing hydrogen sulfide was slightly inferior. Has also been confirmed to exert the effect of reducing hydrogen sulfide.

  Subsequently, using the sample 34 in Experiment 4 (iron powder: 48.5% by weight, coal ash: 48.5% by weight, citric acid: 3% by weight), growth tests of various aquatic organisms were performed.

(Experiment for promoting the growth of microalgae)
A trace amount of nutrient-enriched culture solution Guillard f / 10 (Tris-HCl specified amount added) prepared based on surface seawater (December 14, 2006, collected off Kuga, Yamaguchi Prefecture, GF / C filtered) A mixed metal solution (PS-II, Provasoli) and a mixed vitamin solution, which was sterilized by filtration through a Sterivex 0.02 μm filter, was prepared as a basic culture solution (Guillard f / 2 culture solution).

  150 mL of this was dispensed into a sterilized plastic container for culture (250 mL, Cellstar), and 1.5 g (10 g / L) of sample 34 was added to each. Then, algae was added and cultured as described below.

The algae used were the floating diatom Skeletonema costatum and the attached diatom Nitzschia pelucida, which were added at an initial concentration of about 10 ³ cells / L, 7 times every other day (8 times including initials), and fluoro image analyzer (FLA- 7000, manufactured by Fuji Film Co., Ltd.), fluorescence intensity was measured, and cell proliferation was observed.

Each experiment was performed in triplicate, placed in a lighted incubator, and the temperature was adjusted to S.P. costatum 15 ° C., N.C. Pelucida was cultured at 20 ° C. and light conditions for both species at 200 μmol m ⁻² s ⁻¹ (sample 34 added section).

  In addition, algae were cultured in the same manner as described above except that sample 34 was not added (control group 1: positive control).

  Further, in place of the f / 2 culture solution, surface filtration sterilized seawater was used, and algae were cultured in the same manner as described above without adding the sample 34 (control group 2: negative control).

  S. The results of the growth test of costatum are shown in FIG. The result of the proliferation test of Pellucida is shown in FIG.

  Floating diatom S. In Costatum, the growth was the best in the f / 2 medium (control group 1) containing enough nutrients, but after 14 days, the sample 34-added group had almost the same fluorescence intensity as the f / 2 medium. It was.

  Adherent diatom N. In Pellucida, the growth of the f / 2 medium was better at 8 days, but after 14 days, the sample 34 addition group was better. This means that the nutrient salt is exhausted in the f / 2 medium, but the supply of Fe and other nutrient salts supplied from the sample 34 is considered to be excellent in sustainability. S. If the experiment is continued until 14th or later, N. costum It is highly possible that the same results as with pelucida were obtained.

  Moreover, there was hardly any growth in the filtered seawater (control zone 2), which is probably because there was almost no nutrient salt in the used filtered seawater.

(Clam breeding experiment 1)
On August 9, 2013, 20 kg (200 g / m ² ) of sample 34 was placed in a 10 m × 10 m section of Urashima Kanko Tidal Flat, Onomichi City, Hiroshima Prefecture, and a food damage prevention net was put on it (addition of sample 34) Ward).

  In addition, except that the sample 34 was not put in an area adjacent to the 34 added area, the same scouring was performed and a food damage prevention net was installed (control area).

  Thereafter, on September 6, 2013 and November 21, 2013, clams were collected at the center of each compartment, and the number and size of clams were measured. On September 6, 2013, we collected clams in the bottom mud of length x width x depth = 1 m x 1 m x 0.2 m, and on November 21, 2013, length x width x depth = 0. Clam in the bottom mud of .25m x 0.25m x 0.25m was collected.

  Moreover, the bottom mud from which clams were collected was taken home, and acid volatile sulfides (AVS) and organic carbon (POC) were measured.

  Moreover, on November 21, 2013, the metal concentration in the pore water in the bottom mud of each section was measured by ICP-AES.

  The collection results of clams on September 6, 2013 and November 21, 2013 are shown in FIG. Although there is no advantage in the size of the clams, it can be seen that the number of clams in the group with the sample 34 added is larger than that in the control group.

  Further, FIG. 30 shows the results of POC and AVS, and Table 7 shows the concentrations of Fe, Mn and Zn. Referring to FIG. 30, in the group to which sample 34 was added, the AVS was slightly higher after one month after the start of the growth experiment, but after 3 months or more, the POC was significantly higher and the AVS was higher. You can see that it is significantly lower. Moreover, when Table 7 is seen, it turns out that the Fe and Mn density | concentration is high in the sample 34 addition group compared with the control group. By swallowing sample 34 into the bottom mud, the amount of sulfide (AVS) in the sediment is greatly reduced, and POC, which is an indicator of bait (adherent microalgae), is increased. It is thought that the number of individuals increased.

(Clam breeding experiment 2)
On June 10, 2013, 20 kg (200 g / m ² ) of sample 34 was put in a 10 m × 10 m section at Urashima Ebi Tidal Flat, Onomichi City, Hiroshima Prefecture, and a food damage prevention net was put on it (addition of sample 34) Ward).

  Further, except that the sample 34 was not sown in the area adjacent to the sample 34 added section, plowing was performed in the same manner as described above, and a food damage prevention net was installed (control group).

  Three months after installation (September 11, 2013), the clams in the bottom mud of length x width x depth = 50 cm x 50 cm x 20 cm were collected at three locations in each section, and the number of clams And weighed. Table 8 shows the total number and weight of clams collected at three locations in each section.

  As shown in Table 8, in the group to which sample 34 was added, the number of clams was about 9 times and the weight was about 43 times that of the control group, and both the number of individuals and the weight were significantly increased.

(Clam breeding experiment 3)
On July 8, 2013, 20 kg (200 g / m ² ) of sample 34 was placed in a 10m x 10m section of a tidal flat near the Onomichi fishery cooperative mountain wave branch in Onomichi, and a food damage prevention net was placed on it. (Sample addition section).

  In addition, an anti-corrosion net was installed in the area adjacent to the area where the sample 34 was added, except that the sample 34 was not stirred (control area).

  Three months after installation (September 11, 2013), the clams in the bottom mud of length x width x depth = 50 cm x 50 cm x 20 cm were collected at three locations in each section, and the number of clams And weighed. Table 9 shows the total number and weight of clams collected at three locations in each section.

  As shown in Table 9, in the group to which sample 34 was added, the number of clams was about 6 times and the weight was about 16 times that of the control group, and both the number of individuals and the weight were significantly increased.

  In the above-mentioned clam breeding experiments 1 to 3, the amount of clams collected and the individual weight increased in the sample 34-added section. It is considered that the sample 34 is introduced to improve the bottom sediment of the tidal flat where the clams inhabit, and the attached diatoms that feed on the clams increase, leading to an increase in the survival rate of the clams.

(Oyster breeding experiment)
Using oyster mushrooms in the Kazahaya area of Akitsu-cho, Higashihiroshima City, Hiroshima Prefecture, we conducted oyster propagation experiments.

  A sample 34 was placed on an oyster bowl on which an oyster seeded in July 2013 was suspended. Sample 34 was installed on August 22, 2013 as follows. As shown in FIG. 31 (A), bags containing 300 g of the sample 34 were installed at 15 locations of 15 m × 10 m oyster baskets. As shown in FIG. 31B, the bag containing the sample 34 was hung in two pairs. That is, a sample 34 of 9 kg (300 g / bag × 2 × 15 locations) was placed in one oyster bowl. This is referred to as a 300 g added section.

  Moreover, it installed similarly to the above except putting 100g of samples 34 in a bag. The sample 34 installed in one oyster basket is 3 kg (100 g / bag × 2 × 15). This is referred to as a 100 g added section. In addition, a control section in which the sample 34 was not installed was also provided. The position of each section is shown in FIG.

  On December 10, 2013, oysters were collected at three locations for each compartment, and the weight of the peeled shell was measured. The results are shown in Table 10. In addition, about 100 g addition area and 300 g addition area, the oyster was extract | collected from the drooping oyster near the location in which the sample 34 was installed. In the control group, oysters were randomly collected from the whole oyster mushroom.

  The average weight of oysters is 12.6 g in the control group, 13.3 g in the group with 100 g added, and 14.0 g in the group with 300 g added. It can be seen that the oyster weight increases as the amount of sample 34 added increases. The weight increase rates of the 100 g added group and the 300 g added group with respect to the control group were 6% and 11%, respectively. It is considered that oysters ingested and grew as a result of proliferation of floating diatoms by elution of nutrients such as iron, nitrogen, phosphorus, silica, manganese, and zinc from sample 34.

  In the aquatic organism propagation method according to the present invention, by arranging a fertilizer in the breeding water area of shellfish or algae, various nutrients including iron ions are eluted, so that the growth of these aquatic organisms can be promoted.

Claims (5)

A fertilizer containing coal ash, iron and a chelating agent , wherein the blending ratio of the coal ash and the iron is 3: 7 to 7: 3 in a weight ratio, is placed in a shellfish or algae breeding water area,
Promote the growth of the shellfish or the algae,
An aquatic organism propagation method characterized by the above. Using the fertilizer, wherein the chelating agent is citric acid,
The aquatic organism growth method according to claim 1 . Using the fertilizer containing 3% by weight or more and 7% by weight or less of the citric acid,
The method for growing aquatic organisms according to claim 2 . Eluting iron ions, manganese ions and zinc ions in water, forming iron chelate, manganese chelate and zinc chelate with the chelating agent, using the fertilizer to elute nitrogen, phosphorus and silicon,
While dissolving metal ions from the fertilizer as a complex, eluting nitrogen, phosphorus and silicon, and ingesting them directly or indirectly to the shellfish or the algae,
The aquatic organism propagation method according to any one of claims 1 to 3 , wherein Promote the growth of clams or oysters as the shellfish,
The aquatic organism growth method according to any one of claims 1 to 4 , wherein