Comprehensive spirogyra control method

Abstract

The invention provides a comprehensive spirogyra prevention and control method which comprises the following steps: for spirogyra in a dormancy stage and a germination stage, adding a biological reagent into a water body for spirogyra prevention and control; as for spirogyra in the amplification period and the outbreak period, chemical reagents are added into the water body for emergency prevention and control, and after emergency prevention and control are finished, biological reagents are added to prevent secondary recurrence of the spirogyra. According to the method, proliferation and spreading of spirogyra can be efficiently inhibited, long-term stable prevention and control of spirogyra are achieved, the method is simple, manpower and material resources are saved, and the spirogyra prevention and control efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aquatic ecological restoration and management, and in particular to a method for comprehensive prevention and control of Spirogyra. Background Art

[0002] Spirogyra, a large, filamentous, eukaryotic multicellular algae belonging to the family Diplophyceae of the phylum Chlorophyta, possesses one or more spiral chloroplasts, a surface covered in mucus, and a cell wall composed of an outer layer of cellulose and an inner layer of pectin. Spirogyra thrives in stagnant or slow-flowing waters rich in organic matter. It is highly fertile, reproducing vegetatively by filament breakage and also by conjugation. This robust adaptability and rapid reproduction allow it to rapidly build a massive biomass, a persistent challenge facing open waters.

[0003] Spirogyra growth is mainly divided into four stages: dormancy, germination, expansion and outbreak. During the dormancy stage, Spirogyra is deposited on the surface of the bottom mud in the form of spores, which are colorless and invisible to the naked eye. During the germination stage, it begins to grow, aggregates into green algae spots visible to the naked eye, and begins to float and extend filaments into the water. During the expansion stage, the number of filaments extending into the water increases, gradually forming algae clusters attached to the bottom mud. During the outbreak stage, the algae clusters float to the Spirogyra, and the biomass continues to increase, gradually increasing in size, and then forming Spirogyra algae mats until they decay and die, causing serious damage to water quality and landscape. The real scene of the outbreak stage is shown below. Figure 1 shown.

[0004] The main methods for controlling Spirogyra include physical, chemical, and biological methods. Physical methods mainly use mechanical and manual salvage, which is time-consuming and labor-intensive, and the algae filaments are easily broken and multiplied during salvage. Chemical methods mainly use oxidizing and non-oxidizing chemical algaecides. Oxidizing algaecides include hydrogen peroxide, potassium permanganate, chlorine-containing preparations, etc. Their algaecide effect is fast, but the algaecide effect also decays quickly, and can only achieve short-term control of Spirogyra. Non-oxidizing algaecides include copper sulfate, phenylethyltin copper, copper acetate, triphenyltin acetate, and promethazine, but they have problems such as high toxicity to non-target organisms such as fish and easy negative impacts on the environment. In addition, after algaecide treatment, the algae is dormant and germinates rapidly when conditions are suitable. Secondary outbreaks have always been a serious problem facing Spirogyra treatment. Typical examples include free radical systems such as hydrogen peroxide, chlorine-containing preparations, sodium persulfate, and ferrous sulfate. Moreover, neither physical nor chemical methods can completely control Spirogyra in the long term. The biological method is to use the life activities of plants, animals, etc. to form a competitive relationship with Spirogyra or use Spirogyra as food to achieve the purpose of controlling Spirogyra. Some studies have proposed a "non-classical biological manipulation" theory with filter-feeding fish silver carp and bighead carp as the core. However, there are a large number of undigested algae in the feces of silver carp and bighead carp that can continue to proliferate, and there is a lack of systematic and effective research on the configuration of aquatic plants and fish suitable for different waters. Summary of the Invention

[0005] In order to solve the problems existing in the background technology, the present invention provides a comprehensive control method for Spirogyra, which can effectively inhibit the proliferation and spread of Spirogyra and achieve long-term and stable control of Spirogyra. The method is simple, saves manpower and material resources, and improves the control efficiency of Spirogyra.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: A comprehensive method for controlling Spirogyra, comprising: For Spirogyra in dormant and budding stages, biological reagents are added to the water body for Spirogyra control; For Spirogyra during the amplification and outbreak stages, chemical reagents are added to the water body for emergency prevention and control. After the emergency prevention and control is completed, biological reagents are added to prevent the secondary recurrence of Spirogyra. The principles and beneficial effects of the present invention are as follows: The present invention targets the different growth stages of Spirogyra and proposes to adopt different means for the comprehensive prevention and control of Spirogyra at different stages. For Spirogyra in the expansion and outbreak stages, chemical reagents are used to quickly aggregate the Spirogyra and effectively kill the Spirogyra. For Spirogyra in the dormant and budding stages, biological reagents are used for prevention and control. Through the comprehensive prevention and control system, Spirogyra is killed and its recurrence is avoided, thereby improving the prevention and control effect; and it can greatly reduce the manual workload, save time and labor, and improve the prevention and control efficiency.

[0007] The above-mentioned integrated Spirogyra control method can be applied to artificial composite water bodies and natural water bodies, including but not limited to wetlands, lakes, ponds, rivers, municipal landscape water bodies, domestic sewage treatment plants and other open water bodies.

[0008] According to the above scheme, the comprehensive control method for Spirogyra also includes: planting aquatic plants in the water body and releasing fish and shellfish aquatic animals for long-term control of Spirogyra.

[0009] Long-term control of Spirogyra through aquatic plants and fish, shellfish and other aquatic animals can further prevent the recurrence of Spirogyra, improve the efficiency of Spirogyra control, and reduce harm to the environment. At the same time, it can greatly enhance the ecological value and landscape effect of water bodies, and achieve green and sustainable Spirogyra control in natural water bodies.

[0010] According to the above scheme, the chemical reagents include polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate.

[0011] According to the above scheme, the chemical reagents are added as follows: polyhexamethylene biguanide hydrochloride is applied first, and sodium dichloroisocyanurate is applied 4 to 12 hours later. The effective mass concentration ranges of polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate are 200 to 400 mg / L and 200 to 600 mg / L, respectively.

[0012] The flocculation effect of polyhexamethylene biguanide hydrochloride promotes the rapid aggregation of Spirogyra. After 4 to 12 hours, the Spirogyra is obviously aggregated. Then, the oxidizing effect of polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate is used to quickly kill the Spirogyra. By applying polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate in succession, the Spirogyra can be quickly killed within 1 day, while reducing the dosage of sodium dichloroisocyanurate, with significant prevention and control effects.

[0013] According to the above scheme, the biological agent is a microbial agent, which includes microorganisms that decompose hemicellulose and / or cellulose and microorganisms that decompose pectin.

[0014] The microorganisms that decompose hemicellulose and / or cellulose and the microorganisms that decompose pectin decompose Spirogyra by destroying the cellulose and pectin structural components of the Spirogyra cell wall.

[0015] Furthermore, the microbial agent also includes a carrier, which is a clay mineral with adsorption effect, such as kaolin, montmorillonite, attapulgite and modified products thereof.

[0016] The carrier can adsorb microorganisms thereon. When the microbial agent is added to water, the carrier adsorbs Spirogyra through adsorption, while reducing the phosphorus nutrient salt in the water body. Through the synergistic effect of microorganisms that decompose hemicellulose and / or cellulose, microorganisms that decompose pectin, and kaolin, Spirogyra in the dormant and budding stages is adsorbed and killed, while the phosphorus content in the water body is reduced, and the recurrence of Spirogyra is inhibited.

[0017] According to the above scheme, the microbial agent is added to the water body so that the initial density of bacteria in the water body is controlled at 10 5 -10 7 CFU / mL.

[0018] Optionally, the microbial agent is a fermentation liquid obtained by culturing a microorganism that decomposes hemicellulose / cellulose or a microorganism that decomposes pectin in a liquid culture medium and mixing it with a carrier, and the OD of the fermentation liquid is 600 Controlled between 1.4 and 2.0.

[0019] According to the above scheme, microorganisms that decompose hemicellulose and / or cellulose and microorganisms that decompose pectin are inoculated into the culture medium at an inoculum rate of 1-2%, and fermented at 28-37°C and 150-220 rpm for 8-12 hours, or allowed to ferment statically for 18-36 hours to obtain a fermentation liquid.

[0020] According to the above scheme, the liquid culture medium includes the following components in mass fractions: sucrose 0.8-1.2%, sodium carboxymethyl cellulose 0.3-0.6%, potassium nitrate 0.1-0.2%, sodium chloride 0.05-0.1%, ferrous sulfate 0.005-0.01%, and the balance is water. The carrier accounts for 0.1-0.5% of the mass of the fermentation liquid.

[0021] In another optional solution, the microbial agent is obtained by mixing microorganisms that decompose hemicellulose / cellulose, microbial powder that decompose pectin, nutrients and a carrier.

[0022] According to the above scheme, the nutritional ingredients include sucrose, potassium nitrate, sodium chloride and ferrous sulfate.

[0023] According to the above scheme, the effective viable bacteria count per gram of bacterial powder is greater than 10 10 The mass ratio of the microorganisms that decompose hemicellulose / cellulose, the microbial powder that decomposes pectin, sucrose, potassium nitrate, sodium chloride, ferrous sulfate and the carrier is 2.5-3.5:0.8-1.2:1.5-2.5:0.2-0.6:0.5-1.5:0.015-0.025:4-8.

[0024] According to the above solution, the aquatic plants include at least one of emergent plants, floating-leaf plants, floating plants and submerged plants.

[0025] Furthermore, the emergent plants may be one or more of slender-leaved cattail, large-flowered daylily, aquatic canna, papyrus and water lily; the floating-leaf plants may be one or more of water lily, water nasturtium and water spinach; the floating plants may be one or more of yellow-flowered water dragon, water lily, lotus leaf and duckweed; the submerged plants may be one or two of Vallisneria and spike-flowered foxtail algae.

[0026] Preferably, when the water matrix is ​​suitable for the growth of aquatic plants, for large and medium-sized water areas such as lakes and wetlands (water area ≥ 2,000 square meters), the main body is an ecological floating bed (water surface coverage rate of 20-40%), and a combination of planted emergent plants (water surface coverage rate of 10-20%), floating plants (water surface coverage rate of 10-20%), and submerged plants; for small water areas such as ponds and wetlands (water area < 2,000 square meters), a combination of planted emergent plants (water surface coverage rate of 20-40%), floating plants (water surface coverage rate of 20-40%), and submerged plants; When the water matrix is ​​not suitable for the growth of aquatic plants (such as gravel), for large water bodies such as lakes and wetlands (water area ≥ 2,000 square meters), the main body is ecological floating beds and floating plants (water surface coverage ≥ 60%), combined with submerged plants; for small water bodies such as ponds and wetlands (water area < 2,000 square meters), the main body is floating plants and potted floating-leaf plants (water surface coverage ≥ 60%), combined with submerged plants.

[0027] More preferably, aquatic plants are planted in waters prone to Spirogyra from March to October according to the above principles.

[0028] According to the above scheme, the fish and shellfish aquatic animals are a combination of filter feeders and omnivorous and partially herbivorous aquatic animals, and fish of different water layers, types and sizes are released according to the water area, depth and area.

[0029] According to the above plan, a total of 200-300 fish weighing 20-80 kg are stocked per mu of water surface. This stocking rate ensures effective control of Spirogyra feeding while preventing excessive fish from consuming aquatic plants, causing water turbidity, and deteriorating water quality.

[0030] According to the above scheme, the aquatic organisms are released in the form of a combination of one or more of the following: upper-middle layer filter-feeding fish, lower-middle layer omnivorous fish, benthic omnivorous fish, and filter-feeding shellfish.

[0031] According to the above plan, aquatic organisms are released by combining one or more of silver carp, spiny barb, common carp, yellowtail carp and river clams.

[0032] The upper-middle layer filter-feeding fish silver carp and the lower-middle layer omnivorous fish spiny barb graze on the upper-middle layer and lower-middle layer Spirogyra, the benthic omnivorous fish yellowtail carp and carp scrape the bottom layer and attached Spirogyra, and the filter-feeding shellfish river clams control the Spirogyra remaining in feces. It has been verified in the field in wetlands that Spirogyra can be effectively controlled in the long term.

[0033] Preferably, the weight of a single tail is: silver carp 500-2000g, spiny barb 500-2000g, carp 50-200g, yellowtail carp 50-200g, and river mussel 100-500g.

[0034] Preferably, in spring (April-May) when Spirogyra has not proliferated in large numbers and the water temperature is suitable for fish growth (not less than 16°C, preferably above 20°C), fish are stocked in waters prone to Spirogyra according to the above principles, and the dissolved oxygen level is maintained at 7-10 mg / L. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a real-life picture of the Spirogyra outbreak in test waters 1 to 3 in the fish and shellfish aquatic animal control experiment of the present invention; Figure 2 This is a diagram showing the indoor control effect of Spirogyra when using a single chemical reagent in an embodiment of the present invention; Figure 3 The indoor control effect and secondary recurrence of Spirogyra in the embodiment of the present invention using the combined use of chemical reagents; Figure 4 The morphology of Spirogyra before and after the combined treatment with chemical reagents in the embodiment of the present invention; Figure 5 This is a diagram showing the indoor control effect of the biological reagent on Spirogyra in an embodiment of the present invention; Figure 6This is a diagram showing the field control effect of the biological reagent on Spirogyra in an embodiment of the present invention; Figure 7 This is a diagram showing the control effect of the aquatic plant system on Spirogyra in an embodiment of the present invention; Figure 8 This is a diagram showing the control effect of the fish and shellfish aquatic animal control system on Spirogyra in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The principles and features of the present invention are described below with reference to the accompanying drawings and specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0037] The present invention provides a comprehensive control method for Spirogyra, comprising: adding biological reagents into water bodies for Spirogyra in dormant and budding stages to control the Spirogyra; adding chemical reagents into water bodies for emergency control of Spirogyra in expansion and outbreak stages; and adding biological reagents to control secondary recurrence of Spirogyra after the emergency control is completed. According to the different growth stages of Spirogyra, different means are proposed for comprehensive prevention and control of Spirogyra at different stages. For Spirogyra in the expansion and outbreak stages, chemical reagents can make the Spirogyra quickly agglomerate and effectively kill the Spirogyra. For Spirogyra in the dormant and budding stages, biological reagents are used for prevention and control. Through the integrated prevention and control system, Spirogyra can be killed and its recurrence can be avoided, thereby improving the prevention and control effect. It can also greatly reduce manual workload, save time and effort, and improve prevention and control efficiency.

[0038] The above-mentioned integrated Spirogyra control method is applicable to artificial complex water bodies and natural water bodies, including but not limited to wetlands, lakes, ponds, rivers, municipal landscape water bodies, domestic sewage treatment plants and other open water bodies.

[0039] In some preferred embodiments, the integrated Spirogyra control method further comprises: planting aquatic plants in the water body and releasing fish and shellfish aquatic animals for long-term control of Spirogyra.

[0040] Long-term control of Spirogyra through aquatic plants and fish, shellfish and other aquatic animals can further prevent the recurrence of Spirogyra, improve the efficiency of Spirogyra control, and reduce harm to the environment. At the same time, it can greatly enhance the ecological value and landscape effect of water bodies, and achieve green and sustainable Spirogyra control in natural water bodies.

[0041] In some preferred embodiments, the chemical reagent includes polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate.

[0042] Furthermore, the above-mentioned chemical reagents are added in the following manner: polyhexamethylene biguanide hydrochloride is applied first, and sodium dichloroisocyanurate is applied 4 to 12 hours later. The effective mass concentration ranges of the polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate are 200 to 400 mg / L and 200 to 600 mg / L, respectively.

[0043] The flocculation effect of polyhexamethylene biguanide hydrochloride causes the Spirogyra to agglomerate rapidly. After 4 to 12 hours, the Spirogyra is obviously agglomerated. Then, the oxidative action of polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate rapidly kills the Spirogyra. By applying polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate in succession, the Spirogyra can be rapidly killed within 1 day, while the dosage of sodium dichloroisocyanurate is reduced, resulting in a significant control effect.

[0044] In some specific embodiments of the present invention, the biological agent is a microbial agent, which includes microorganisms that decompose hemicellulose and / or cellulose, and microorganisms that decompose pectin.

[0045] Microorganisms that decompose hemicellulose and / or cellulose and microorganisms that decompose pectin break down the sponge by destroying the cellulose and pectin structural components of the Spirogyra cell wall.

[0046] The microorganisms used are not limited to a specific strain; any strain having the ability to decompose hemicellulose and / or cellulose, and the ability to decompose pectin can be used, such as Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus cereus, Bacillus megaterium, etc. In some specific embodiments of the present invention, the microbial agent used is Bacillus subtilis ACCC11089 (purchased from Shanghai Microorganism Collection Center) that has the ability to decompose hemicellulose, and Bacillus amyloliquefaciens bio-61576 (purchased from Beijing Biobo Biotechnology Co., Ltd.) that has the ability to decompose pectin.

[0047] Furthermore, the microbial agent also includes a carrier, which is a clay mineral with adsorption effect, such as kaolin, montmorillonite, attapulgite and modified products thereof.

[0048] The carrier can adsorb microorganisms thereon. When the microbial agent is added to water, the carrier adsorbs Spirogyra through adsorption, while reducing the phosphorus nutrient salt in the water body. Through the synergistic effect of microorganisms that decompose hemicellulose and / or cellulose, microorganisms that decompose pectin, and kaolin, Spirogyra in the dormant and budding stages is adsorbed and killed, while the phosphorus content in the water body is reduced, and the recurrence of Spirogyra is inhibited.

[0049] In some preferred embodiments, the microbial agent is added to the water body so that the initial density of bacteria in the water body is controlled at 10 5 -10 7 CFU / mL.

[0050] In an optional embodiment, the microbial agent is a fermentation liquid obtained by culturing a microorganism that decomposes hemicellulose / cellulose or a microorganism that decomposes pectin in a liquid culture medium and mixing it with a carrier, and the OD of the fermentation liquid is 600 Controlled between 1.4 and 2.0.

[0051] Preferably, the microorganisms that decompose hemicellulose and / or cellulose and the microorganisms that decompose pectin are inoculated into the culture medium at an inoculum size of 1-2%, and fermented at 28-37° C. and 150-220 rpm for 8-12 hours, or allowed to ferment statically for 18-36 hours to obtain a fermentation liquid.

[0052] Preferably, the liquid culture medium comprises the following components in mass fractions: sucrose 0.8-1.2%, sodium carboxymethyl cellulose 0.3-0.6%, potassium nitrate 0.1-0.2%, sodium chloride 0.05-0.1%, ferrous sulfate 0.005-0.01%, and the balance is water. The carrier accounts for 0.1-0.5% of the mass of the fermentation broth.

[0053] In another optional embodiment, the microbial agent is obtained by mixing microorganisms that decompose hemicellulose / cellulose, microbial powder that decompose pectin, nutrients and a carrier.

[0054] Preferably, the above-mentioned nutrients include sucrose, potassium nitrate, sodium chloride and ferrous sulfate.

[0055] Preferably, the effective viable bacteria count per gram of bacterial powder is greater than 10 10 The mass ratio of the microorganisms that decompose hemicellulose / cellulose, the microbial powder that decomposes pectin, sucrose, potassium nitrate, sodium chloride, ferrous sulfate and the carrier is 2.5-3.5:0.8-1.2:1.5-2.5:0.2-0.6:0.5-1.5:0.015-0.025:4-8.

[0056] Spirogyra is a large eukaryotic green algae with long algal bodies that easily entangle and aggregate to form clumps or sheets. Therefore, microbial reagents are only suitable for the prevention and control of low-biomass Spirogyra during the dormant and germination stages.

[0057] Since biological and chemical reagents require long-term external application of reagents, high dosage and high reagent costs, they can only be used for Spirogyra in the dormant, germination, expansion and outbreak stages, and cannot cure Spirogyra completely. Therefore, constructing an aquatic plant system and a fish and shellfish aquatic animal system is the first and most preferred choice for controlling Spirogyra in practical applications.

[0058] The aquatic plants include at least one of emergent plants, floating-leaf plants, floating plants and submerged plants.

[0059] Furthermore, the emergent plants may be one or more of slender-leaved cattail, large-flowered daylily, aquatic canna, papyrus and water lily; the floating-leaf plants may be one or more of water lily, water nasturtium and water spinach; the floating plants may be one or more of yellow-flowered water dragon, water lily, lotus leaf and duckweed; the submerged plants may be one or two of Vallisneria and spike-flowered foxtail algae.

[0060] Preferably, when the water matrix is ​​suitable for the growth of aquatic plants, for large and medium-sized water areas such as lakes and wetlands (water area ≥ 2,000 square meters), the main body is an ecological floating bed (water surface coverage rate of 20-40%), and a combination of planted emergent plants (water surface coverage rate of 10-20%), floating plants (water surface coverage rate of 10-20%), and submerged plants; for small water areas such as ponds and wetlands (water area < 2,000 square meters), a combination of planted emergent plants (water surface coverage rate of 20-40%), floating plants (water surface coverage rate of 20-40%), and submerged plants; When the water matrix is ​​not suitable for the growth of aquatic plants (such as gravel), for large water bodies such as lakes and wetlands (water area ≥ 2,000 square meters), the main body is ecological floating beds and floating plants (water surface coverage ≥ 60%), combined with submerged plants; for small water bodies such as ponds and wetlands (water area < 2,000 square meters), the main body is floating plants and potted floating-leaf plants (water surface coverage ≥ 60%), combined with submerged plants.

[0061] More preferably, aquatic plants are planted in waters prone to Spirogyra from March to October according to the above principles.

[0062] The four major categories of aquatic plants, namely floating, floating-leaf, emergent and submerged, are combined with different planting forms and can be widely used in the prevention and control of Spirogyra in wetlands of different sizes and substrate types. Different from aquatic plants that secrete allelopathic substances to indirectly inhibit cyanobacteria, aquatic plants directly inhibit the growth and large-scale proliferation and spread of Spirogyra through competition for sunlight and nutrients. Aquatic plants have excellent control effects on Spirogyra, a large eukaryotic algae. Field verification shows that Spirogyra basically disappears in areas covered by the main growth of the plants, and a small amount of Spirogyra exists in some uncovered waters. Spirogyra does not break out during the high temperatures of summer, and there is no need for frequent manual salvage of Spirogyra.

[0063] In some specific embodiments, the fish and shellfish aquatic animals are a combination of filter feeders and omnivorous and partially herbivorous aquatic animals, and fish of different water layers, species, and sizes are released according to the water area, depth, and area.

[0064] According to the above plan, a total of 200-300 fish weighing 20-80 kg are stocked per mu of water surface. This stocking rate ensures effective control of Spirogyra feeding while preventing excessive fish from consuming aquatic plants, causing water turbidity, and deteriorating water quality.

[0065] Spirogyra has a vertical distribution in the water body, which mainly depends on water temperature, light, water flow and hydrodynamic conditions. Affected by water temperature and light, Spirogyra usually grows in the middle and lower layers in spring, gradually moves to the upper layers to float on the water surface in summer, moves to the middle and lower layers in autumn, and sinks to the bottom layer in winter. Affected by water flow and hydrodynamics, Spirogyra grows and spreads in large quantities in still water areas, distributed in various water layers, slow-flowing areas and rapid-flowing areas. Spirogyra usually attaches to objects such as stones, or is distributed in the marginal areas where the water flow is relatively slow to avoid being washed away by the water flow. Taking into account the vertical distribution characteristics of Spirogyra, the aquatic organisms are released in a combination of one or more of the following: filter-feeding fish in the middle and upper layers, omnivorous fish in the middle and lower layers, benthic omnivorous fish, and filter-feeding shellfish.

[0066] According to the above scheme, one or more of the fish species distributed in different water layers including the upper-middle layer filter-feeding fish silver carp, the lower-middle layer omnivorous fish spinulosa, the benthic omnivorous fish common carp and yellowtail carp, and the filter-feeding shellfish mussels are used to feed on Spirogyra.

[0067] Silver carp, a filter-feeding fish in the upper and middle layers, and spiny barb, a omnivorous fish in the lower and middle layers, graze on Spirogyra in the upper and middle layers. Spiny barb enhances Spirogyra digestion through mechanical crushing with its throat teeth and has a relatively strong ability to digest Spirogyra. Yellowtail carp and carp, benthic omnivorous fish, scrape Spirogyra from the bottom layer and attached areas such as stones. Filter-feeding shellfish clams are used to ingest undigested vital Spirogyra in feces, controlling the amount of Spirogyra remaining in feces. Field verification in wetlands has shown that Spirogyra can be effectively controlled in the long term.

[0068] Preferably, the weight of a single tail is: silver carp 500-2000g, spiny barb 500-2000g, carp 50-200g, yellowtail carp 50-200g, and river mussel 100-500g.

[0069] Preferably, in spring (April-May) when Spirogyra has not proliferated in large numbers and the water temperature is suitable for fish growth (not less than 16°C, preferably above 20°C), fish are stocked in waters prone to Spirogyra according to the above principles, and the dissolved oxygen level is maintained at 7-10 mg / L.

[0070] Field verification has shown that in an aquatic environment where only aquatic organisms are released and no aquatic plants are planted, the above-mentioned fish, after being domesticated in an environment where Spirogyra is the main food source, have an excellent feeding effect on Spirogyra. The existing high biomass Spirogyra has completely disappeared, the water body is clear, there is no obvious reproduction of Spirogyra, the size and weight of the fish have increased significantly, and there is no outbreak of Spirogyra in the high summer temperature.

[0071] The following are specific examples.

[0072] (1) Chemical control test of Spirogyra Two chemical agents, polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate, were used alone and in combination to test their efficacy against Spirogyra.

[0073] 1. Indoor test on the control of Spirogyra using chemical reagents alone Sodium dichloroisocyanurate and polyhexamethylene biguanide hydrochloride were weighed separately and mixed with 5L of water to prepare 100, 200, 400, 600, 800, and 1000mg / L polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate reagents, respectively. Two experimental groups were set up: Group I, in which 40g of wet weight of Spirogyra was added to a plastic box and a gradient of sodium dichloroisocyanurate concentrations were added; Group II, in which 40g of wet weight of Spirogyra was added to a plastic box and a gradient of polyhexamethylene biguanide hydrochloride concentrations were added. The killing rate of Spirogyra was measured after 12 hours.

[0074] The killing rates and effects of chemical reagents of different mass concentrations on Spirogyra are shown in Table 1 below: Table 1 The killing effect of chemical reagents on Spirogyra when used alone

[0075] The results showed that for 40g of Spirogyra, when the effective mass concentration was 100, 200, 400, 600, 800 and 1000 mg / L, the 12h killing rate of sodium dichloroisocyanurate was 44%, 67%, 83%, 99%, 100% and 100%, respectively; the Spirogyra in the polyhexamethylene biguanide hydrochloride treatment group showed obvious aggregation, and the 12h killing rate was 15%, 19%, 29%, 35%, 37% and 33%, respectively.

[0076] The effect of using chemical reagents alone on indoor control of Spirogyra is shown in the figure below. Figure 2 As shown in the figure, 12 hours after the addition of chemical reagents, when the concentration of sodium dichloroisocyanurate treatment group was ≥200 mg / L, the yellowing area of ​​​​Spigodia was >60%, indicating that sodium dichloroisocyanurate had a strong effect in killing Spirogeia immediately. The Spirogeia in the polyhexamethylene biguanide hydrochloride treatment group showed obvious aggregation and partial yellowing, indicating that polyhexamethylene biguanide hydrochloride had an adsorption and flocculation effect on Spirogeia, but its immediate killing effect on high-biomass Spirogeia was weak.

[0077] 2. Laboratory test on the control effect and secondary recurrence of Spirogyra using combined chemical reagents Weigh 1, 1.5, 2, and 2.5 g of sodium dichloroisocyanurate and polyhexamethylene biguanide hydrochloride, respectively, and add 5 L of water for thorough mixing to prepare concentrations of 200, 300, 400, and 500 mg / L of polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate, respectively. Add 20 g of Spirogyra (wet weight) to a plastic box. The above chemical reagents, alone or in combination, were used to test the Spirogyra kill rate after 12 hours and the recurrence rate after 6 days. The results are shown in Table 2.

[0078] Table 2 The killing effect and secondary recurrence of Spirogyra after combined use of chemical reagents

[0079] The effect of combined use of chemical reagents on indoor control of Spirogyra and secondary recurrence is shown in the figure below. Figure 3 As shown, 12 hours after addition, the Spirogyra in the polyhexamethylene biguanide hydrochloride + sodium dichloroisocyanurate treatment group completely turned yellow, and the Spirogyra killing rate was 100%; 6 days after addition, the Spirogyra in the polyhexamethylene biguanide hydrochloride treatment group completely turned yellow, all the Spirogyra in the sodium dichloroisocyanurate treatment group relapsed for the second time, and the Spirogyra in the polyhexamethylene biguanide hydrochloride + sodium dichloroisocyanurate treatment group did not relapse for the second time, indicating that the addition of polyhexamethylene biguanide hydrochloride helps inhibit the secondary recurrence of Spirogyra.

[0080] Figure 4 After the combined use of polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate, the morphology of Spirogyra under an optical microscope showed that the cell wall and cell membrane structure of the Spirogyra in the control group were intact, and the spiral chloroplasts were clearly visible (bright green); 12 hours after the addition, there was no obvious breakage between the cell walls, the surface morphology was obviously distorted, the chloroplasts were destroyed, and the photosynthetic activity was completely lost; 6 days after the addition, the cell wall was obviously broken, the Spirogyra filaments were broken into multiple segments, and the photosynthetic activity did not recover.

[0081] In outdoor waters, Spirogyra can proliferate significantly within 24 to 48 hours under suitable conditions. Therefore, the killing and prevention of Spirogyra during the expansion and outbreak periods require timely killing within a short period of time and effective prevention of secondary recurrence.

[0082] Both polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate can kill Spirogyra. When used alone, sodium dichloroisocyanurate has a better killing effect on Spirogyra than polyhexamethylene biguanide hydrochloride. However, due to the rapid decomposition of sodium dichloroisocyanurate and the rapid decrease in its residual amount in water bodies, it cannot maintain a sustained inhibitory effect on Spirogyra, which is prone to secondary recurrence. Although polyhexamethylene biguanide hydrochloride has a slightly worse killing effect on Spirogyra, it has a longer duration of action on Spirogyra, can hinder cell division and reproduction, and inhibit the recurrence of Spirogyra. When the two are used together, polyhexamethylene biguanide hydrochloride has cationic properties. By electrostatically attracting the negatively charged components on the cell wall and cell membrane of Spirogyra, it enhances the effect of sodium dichloroisocyanurate on cell structure destruction, impairing the integrity of the cell structure, leaking intracellular substances, disrupting the synthesis of pigments such as chlorophyll, affecting the normal physiological function of the cells, and inhibiting the recurrence of Spirogyra.

[0083] (2) Experiment on biological control of Spirogyra 1. Indoor test on the control effect of biological reagents on Spirogyra Weigh 12g of sucrose, 0.6g of sodium carboxymethyl cellulose, 2g of potassium nitrate, 1g of sodium chloride, and 0.1g of ferrous sulfate to prepare 1L of liquid culture medium. Inoculate the liquid culture medium with Bacillus subtilis and Bacillus amyloliquefaciens seed liquid at a 2% inoculum volume and culture at 30°C and 180 rpm for 12h to obtain the OD value. 600 The fermentation broth was 1.6 g and then mixed with 5 g of kaolin to obtain a biological reagent.

[0084] 10 g of Spirogyra in good growth condition was placed in 4 L of water, and 40 mL of biological reagent was added in a plastic box. The morphology of the Spirogyra was observed using an optical microscope after 7 and 21 days of treatment. Figure 5 This is a diagram showing the indoor control effect of biological reagents on Spirogyra. The results of visual observation show that on the 7th day of treatment, the microorganisms multiplied rapidly, but the Spirogyra did not show obvious yellowing. On the 21st day, the Spirogyra basically turned yellow. Optical microscopy showed that on the 7th day, the cell walls between the Spirogyra's chain cells were destroyed, the filamentous cells were obviously broken, and the chloroplast structure was partially destroyed. On the 21st day, the degree of damage to the Spirogyra's chain structure was aggravated, the cell contents flowed out, and the Spirogyra died.

[0085] 2. Field test of the control effect of biological reagents on Spirogyra Biological reagents were used to control Spirogyra in the field test area 4. Photos of the test area 4 before and after control are shown below. Figure 6 As shown, the test water area 4 is about 380m 2 The average water depth is 30cm. At the end of March, Spirogyra is in the germination period, and a large number of green Spirogyra patches appear on the water surface.

[0086] Take 100 L of water from test water area 4, weigh 2280 g of kaolin and add it to the water, and then add 1140 g of Bacillus subtilis powder, 380 g of Bacillus amyloliquefaciens powder, 760 g of sucrose, 152 g of potassium nitrate, 456 g of sodium chloride, and 7.6 g of ferrous sulfate in sequence. After stirring evenly, let it stand at 25-35°C for 1 hour to activate it to obtain a biological reagent, which was then sprayed into test water area 4. After 28 days of treatment, the Spirogyra completely disappeared.

[0087] (3) Aquatic plant control test 1. Experiment on the control effect of aquatic plants on Spirogyra in soil matrix water area Test areas 5-8 used soil as the substrate. In Area 5, an ecological floating bed was used to plant emergent plants and submerged Myriophyllum spicateum; in Area 6, the floating plants were Water Dragon and Achyranthes sphenophyllum; in Area 7, the emergent plant Papyrus, the floating-leaf plant Water Lily, and the submerged Myriophyllum; and in Area 8, the floating-leaf plant Water Lily and the submerged plant Vallisneria. Long-term observations showed that even after the large-scale coverage of the Spirogyra infestation area with aquatic plants, no large-scale outbreaks of Spirogyra were observed, although localized Spirogyra remained at the edges of the water bodies.

[0088] 2. Experiment on the control effect of aquatic plants on Spirogyra in gravel-based waters Test areas 9 and 10 used gravel as the primary substrate. Area 9 featured emergent plants such as papyrus and typha serrata, floating plants such as water dragon (Phyllostachys chrysantha), and submerged plants such as Vallisneria salsa. Area 10 was planted in pots with floating plants such as water lilies (Phyllostachys serrata), emergent plants such as typha serrata, and floating plants such as duckweed. Long-term observations revealed that even after the large-scale coverage of the Spirogyra infestation area with aquatic plants, no large-scale outbreaks of Spirogyra were observed, although localized areas of Spirogyra remained at the edges of the water body.

[0089] Figure 7 This is a diagram showing the effect of aquatic plant system on the prevention and control of Spirogyra. Floating-leaf plants, floating plants, emergent plants, etc. cover a large area of ​​the surface area where Spirogyra occurs, and submerged plants occupy the middle and lower areas where Spirogyra occurs. First, they effectively reduce the concentration of nutrient salts in the water body by absorbing nitrogen and phosphorus nutrients. Second, they reduce the intensity of light at the bottom of the water through the physical shielding effect, thereby reducing the photosynthesis efficiency of Spirogyra. After planting aquatic plants, no large-scale growth outbreaks of Spirogyra were found, and only local Spirogyra existed in the edge areas of the water body.

[0090] (IV) Fish and shellfish aquatic animal prevention and control experiments Figure 1 These are actual scenes of Spirogyra outbreaks in test waters 1 to 3, from June to August, when Spirogyra was in its outbreak period. In test water 1, Spirogyra covered over 90% of the water surface, occupying all of the surface, middle, and lower layers; in test water 2, Spirogyra covered over 60% of the water surface, occupying most of the surface, middle, and lower layers; in test water 3, Spirogyra covered over 30% of the water surface, occupying a small portion of the surface, middle, and lower layers.

[0091] According to the distribution of Spirogyra in experimental waters 1 to 3, fish and shellfish were released respectively. The specific release conditions are as follows: Test waters 1, area of ​​about 30m 2 At an average water depth of 60cm, 50 carp fry, approximately 10-20cm in size and weighing 20-100g, and 10 silver carp, approximately 30-50cm in size and weighing 500-1000g, were stocked. After one month of observation, the Spirogyra was completely eradicated, the fish showed significant growth, and no Spirogyra outbreak occurred during the peak period of Spirogyra outbreaks in summer. Test waters 2, area of ​​about 800m 2 The average water depth was 1.2m. 100 silver carp, approximately 30-50cm in size and weighing 500-1500g, and 150 yellowtail carp, approximately 20-30cm in size and weighing 100-200g, were stocked. 50 mussel shells were also stocked, totaling approximately 120kg. After one month of observation, large-scale Spirogyra infestations were essentially eliminated, and no Spirogyra outbreaks occurred during the peak summer season. Test waters 3, area of ​​about 980m 2The average water depth was 1.5m, and 80 silver carp with a size of about 30-50cm and a weight of about 500-1500g, 80 spiny barb with a size of about 30-50cm and a weight of about 500-1500g were stocked, and 50 clam shells were used, with a stocking weight of about 160kg; after one month of observation, the Spirogyra was basically eliminated, and no Spirogyra outbreak occurred during the peak period of Spirogyra outbreak in summer.

[0092] After 1 month, the control effect is as follows Figure 8 As shown in Figure 1, Spirogyra completely disappeared from Test Area 1, the water was clear, fish size and weight increased significantly, and there was no Spirogyra outbreak during the summer heat wave. In Test Area 2, large-scale Spirogyra basically disappeared, and there was no Spirogyra outbreak during the summer heat wave. In Test Area 3, Spirogyra basically disappeared, with only localized Spirogyra remaining in marginal areas during the summer heat wave.

[0093] Spirogyra has a vertical distribution within water bodies, primarily determined by water temperature, light intensity, currents, and hydrodynamic conditions. Influenced by water temperature and light intensity, Spirogyra typically grows in the lower and middle layers in spring, gradually moving to the upper layers to float on the surface in summer, then to the lower and middle layers in autumn, sinking to the bottom layer in winter. Influenced by currents and hydrodynamics, Spirogyra grows abundantly in still waters, spreading throughout all water layers. In areas with slow and rapid currents, Spirogyra often attaches to objects such as rocks or to the edges of relatively slow currents to avoid being swept away. Considering Spirogyra's vertical distribution, fish species from different water layers, including the pelagic filter-feeding silver carp, the pelagic omnivorous light-barbed target, the bottom-feeding omnivorous common carp and yellowtail carp, and the filter-feeding mussels, were used to monitor Spirogyra. In addition, the omnivorous fish, Spinella glabra, enhances the digestion of Spirogyra through mechanical crushing with its pharyngeal teeth, and has a relatively strong ability to digest Spirogyra; the benthic fish, Yellowtail carp, feeds on Spirogyra on the bottom and attached areas such as stones by scraping, and uses shellfish such as clams to feed on undigested and vital Spirogyra in feces.

[0094] In an aquatic environment stocked only with fish and shellfish, without aquatic plants, the aforementioned fish, after being acclimated to Spirogyra as their primary food source, showed excellent results in consuming the Spirogyra. Existing high biomass of Spirogyra completely disappeared, the water became clear, Spirogyra showed no significant reproduction, and the fish significantly increased in size and weight. There were no Spirogyra outbreaks during the summer heat. Furthermore, after the Spirogyra had been consumed, the fish were left food-starved, requiring additional fish food sources.

[0095] Due to restrictions on water depth, water temperature, dissolved oxygen, equipment safety, and management costs, the release of aquatic animals such as fish and shellfish cannot cover a variety of scenarios, including municipalities, environmental protection facilities such as sewage treatment plants, and agriculture. These include municipal landscape water bodies (frequent drainage is not conducive to fish survival), domestic sewage treatment process units (fish block pipes, posing risks to equipment safety operation, and the environment is unsuitable for fish survival), shallow water bodies (such as irrigation canals and shallow surface flow artificial wetlands where fish are prone to death in summer and winter), irrigation and drainage operation areas (regular discharge prevents fish from settling), areas with dense aquatic plant plantings (dense vegetation hinders fish activity and affects their normal survival during harvesting), and low-oxygen environments (dissolved oxygen in fish is not less than 5 mg / L). In the above scenarios, chemical reagents and / or biological reagents can be used to prevent and control water sponge.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for the comprehensive prevention and control of Spirogyra, characterized in that: include: For Spirogyra in dormant and budding stages, biological reagents are added to the water body for Spirogyra control; For Spirogyra during the amplification and outbreak stages, chemical reagents are added to the water body for emergency prevention and control. After the emergency prevention and control is completed, biological reagents are added to prevent the secondary recurrence of Spirogyra.

2. The method for comprehensive control of Spirogyra according to claim 1, characterized in that: Also includes: Planting aquatic plants and releasing fish, shellfish and other aquatic animals in water bodies are used for long-term prevention and control of Spirogyra.

3. The method for comprehensive control of Spirogyra according to claim 1 or 2, characterized in that: The chemical reagents include polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate.

4. The method for comprehensive control of Spirogyra according to claim 3, characterized in that: The chemical reagents are added in the following manner: polyhexamethylene biguanide hydrochloride is first applied, and sodium dichloroisocyanurate is applied 4 to 12 hours later. The effective mass concentration ranges of the polyhexamethylene biguanide hydrochloride and sodium dichloroisocyanurate are 200 to 400 mg / L and 200 to 600 mg / L, respectively.

5. The method for comprehensive control of Spirogyra according to claim 1 or 2, characterized in that: The biological agent is a microbial agent, which includes microorganisms that decompose hemicellulose and / or cellulose and microorganisms that decompose pectin.

6. The method for comprehensive control of Spirogyra according to claim 5, characterized in that: The microbial agent further comprises a carrier, and the carrier is a clay mineral with adsorption function.

7. The method for comprehensive control of Spirogyra according to claim 6, characterized in that: The microbial agent is added to the water body so that the initial density of bacteria in the water body is controlled at 10 5 -10 7 CFU / mL.

8. The method for comprehensive control of Spirogyra according to claim 2, characterized in that: The aquatic plants include at least one of emergent plants, floating-leaf plants, floating plants and submerged plants.

9. The method for comprehensive control of Spirogyra according to claim 2, characterized in that: The fish and shellfish aquatic animals are a combination of filter feeders, omnivorous and partially herbivorous organisms, and fish of different water layers, types and sizes are released according to the water area, depth and area.

10. The method for comprehensive control of Spirogyra according to claim 9, characterized in that: The fish and shellfish aquatic animals are released in a combination of one or more of upper and middle layer filter-feeding fish, lower and middle layer omnivorous fish, benthic omnivorous fish, and filter-feeding shellfish.

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