Multi-nutrition-level ecological breeding system suitable for freshwater fish breeding

Abstract

The invention discloses a multi-nutrition-level ecological breeding system suitable for freshwater fish breeding, and belongs to the technical field of ecological breeding. The ecological breeding system is provided with a plurality of nutrition levels, the nutrition levels at least comprise a fish nutrition level, a filter-feeding shellfish nutrition level and a benthic organism nutrition level, the ecological breeding system further comprises submerged plants, and the ecological breeding system is characterized in that the bottom layer of the ecological breeding system is the benthic organism nutrition level, and the bottom layer of the ecological breeding system is the filter-feeding shellfish nutrition level. The benthic organism nutrition level comprises ecological concrete and biochar, the biochar provides a habitat for benthic organisms, the ecological concrete provides an activity space for the benthic organisms, and submerged plants are fixed by a porous structure of the ecological concrete. According to the multi-nutrition-level ecological breeding system suitable for freshwater fish breeding, organic matter pollutants and heavy metal in sediments at the water bottom can be effectively removed, the stability of the sediments is improved, and resuspension of the organic matter pollutants, caused by water flow disturbance, of the sediments is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ecological breeding, and in particular to a multi-nutrient level ecological breeding system suitable for freshwater fish breeding. Background Art

[0002] Integrated Multi-Trophic Aquaculture (IMTA) that has emerged in recent years uses the materials and energy of the aquaculture waters, the ecological mutual benefits between organisms, and the carrying capacity of the aquaculture waters for aquaculture organisms to reasonably match organisms at different trophic levels. For example, the proportions of fish, shrimps and crabs, filter-feeding shellfish, and large algae enable a certain type of aquatic organism to utilize the metabolites of another type of aquatic organism. The aquatic organisms that need to be fed are mixed with aquatic animals and plants that do not need to be fed in a scientific proportion, so that the by-products of one type of aquaculture organism, such as feces and residual food, become the input of another type of aquaculture organism, such as food for filter-feeding shellfish or fertilizer for plants, to achieve the recycling of materials in the aquaculture system. Chinese utility model patent CN 203723260 U discloses a multi-trophic level integrated aquaculture system for aquaculture in offshore waters, specifically, fish are cultured in upper cages; shellfish are cultured in middle cages; benthic marine organisms are cultured in lower cages; fish food is placed in the upper cages, and the biological excrement of the upper layer falls into the lower layer and can be used as food for the organisms in the lower layer. Compared with existing cage aquaculture and raft aquaculture, it can effectively avoid local pollution of the seabed, but the cultured shellfish and benthic marine organisms do not live naturally on the seabed. Even if the biological excrement of the upper layer falls into the lower layer and can be used as food for the organisms in the lower layer, the biological excrement will not be fully utilized in the water body, and long-term accumulation will still lead to an increase in organic matter in the seabed sediments. The same is true for the multi-trophic level ecological farming system for freshwater fish farming. The organic matter in the sediment is decomposed by microorganisms and consumes dissolved oxygen, which may form anaerobic conditions at the bottom of the ecological farming system, leading to the production of harmful substances such as hydrogen sulfide. The decomposition of organic matter will produce CO2 and other organic acids, which will lower the pH value of the water, reduce water quality, and affect the health of aquatic organisms.

[0003] Excessive disturbance of sediments will affect the activity of microorganisms in the sediments. The existing mechanical removal of bottom sediments often destroys the sediments, which easily leads to changes in the structure of microbial communities. The release of organic pollutants in the sediments can easily cause toxicity and bioaccumulation of aquatic organisms. Even if fishing activities are carried out on the water surface, the sediments will be excessively disturbed. Therefore, the multi-trophic level ecological aquaculture system for freshwater fish farming has deficiencies in the methods of removing sediments and controlling organic pollutants in sediments. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a multi-trophic level ecological breeding system suitable for freshwater fish breeding, which can effectively remove organic pollutants and heavy metals in sediments on the bottom of the water, improve the stability of the sediments, and reduce the re-suspension of organic pollutants in the sediments caused by water flow disturbance.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A multi-trophic level ecological aquaculture system suitable for freshwater fish farming, the ecological aquaculture system having a plurality of trophic levels, the plurality of trophic levels including at least a fish trophic level, a filter-feeding shellfish trophic level, and a benthic organism trophic level, the ecological aquaculture system also including submerged plants, characterized in that the bottom layer of the ecological aquaculture system is the benthic organism trophic level, the benthic organism trophic level includes ecological concrete and biochar, the biochar provides a habitat for benthic organisms, the ecological concrete provides an activity space for the benthic organisms, and the porous structure of the ecological concrete fixes the submerged plants.

[0007] Furthermore, the porosity of the ecological concrete is at least above 20%.

[0008] Furthermore, the benthic organisms include clams, snails, water earthworms, chironomid larvae, shrimps and crabs.

[0009] Furthermore, the biochar is converted through a pyrolysis process, and the raw material of the biochar comes from one of agricultural waste, forestry waste or aquatic plants.

[0010] Furthermore, the agricultural waste is rice husk or straw; the forestry waste is wood chips or sawdust; and the aquatic plant is water hyacinth or algae.

[0011] Furthermore, the bottom layer of the ecological breeding system is composed of ecological concrete, biochar and limestone.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The present invention provides a multi-trophic level ecological breeding system suitable for freshwater fish breeding. In the bottom layer of the ecological breeding system, biochar can effectively absorb organic pollutants and heavy metals in sediments through high adsorption, directly improve water quality, and reduce the release of organic pollutants in sediments into the water body. On the other hand, biochar provides more habitats for microorganisms in sediments and promotes the activities of microorganisms in sediments. Extracellular polymers (EPS) secreted by microorganisms can enhance the stability of sediments. At the same time, the ecological concrete has a porous structure, which can provide a habitat space for microorganisms and a stable attachment matrix for submerged plants, which is beneficial to the development of root systems and helps to form stable underwater vegetation. Through the photosynthesis of plants and the absorption of roots, it helps to absorb nutrients such as nitrogen and phosphorus in the water body, reduce eutrophication of water bodies, indirectly improve water quality, and enhance the self-purification capacity of water bodies. The porous structure of the ecological concrete can also slow down the water flow rate, reduce the direct scouring of sediments by water flow, and protect microbial communities. The combined use of biochar and eco-concrete provides a diverse microenvironment for microorganisms, increases the biodiversity of microbial communities, and improves the ability of microbial communities to degrade organic pollutants in sediments. It can effectively degrade organic pollutants in sediments and reduce toxic effects on benthic organisms, thereby protecting benthic organisms from harm by harmful substances; it also improves the physical structure of sediments, increases their air permeability and water retention, and improves the stability of sediments. Plant roots can penetrate biochar and sediments, and the entanglement and secretions of their roots help to fix sediments and reduce the resuspension of pollutants caused by water disturbance. DETAILED DESCRIPTION

[0014] The present invention is further described below in conjunction with specific embodiments. It should be noted that, under the premise of no conflict, the embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0015] Green ecological concrete refers to concrete and its products that use special concrete with a certain strength and porosity as the skeleton, with the substances required for plant growth filled in the concrete pores. It is able to adapt to the growth of green plants and is also a porous concrete structure in structure.

[0016] Ecological concrete is a new type of material with performance between ordinary concrete and cultivated soil. It is made of lightweight porous rocks, biological organic fertilizers, cultivated soil, etc., and is cemented with cementitious materials. It has a certain strength and relatively small mass. It can form "honeycomb-like" gaps, which are conducive to the growth of vegetation roots and provide storage space for nutrients necessary for vegetation growth. It consists of a cushion layer (cultivated soil), a matrix layer (large pore concrete and filler) and a surface layer (vegetation layer). Ecological concrete is provided by Hunan Huanmei Kechuang Ecological Technology Co., Ltd.

[0017] Example 1

[0018] The present embodiment provides a multi-trophic level ecological aquaculture system suitable for freshwater fish farming. The ecological aquaculture system has multiple trophic levels, and the multiple trophic levels include at least fish trophic levels, filter-feeding shellfish trophic levels, and benthic organism trophic levels. The ecological aquaculture system also includes submerged plants. The bottom layer of the ecological aquaculture system is the benthic organism trophic level. The benthic organism trophic level includes ecological concrete and biochar. The biochar provides a habitat for benthic organisms, and the ecological concrete provides an activity space for benthic organisms. The porous structure of the ecological concrete fixes the submerged plants, and the porosity of the ecological concrete is 20%.

[0019] Benthic organisms include clams, snails, earthworms, midge larvae, shrimps and crabs.

[0020] The raw materials of biochar come from agricultural waste, forestry waste or aquatic plants. Agricultural waste is rice husk or straw; forestry waste is wood chips or sawdust; aquatic plants are water hyacinth or algae.

[0021] In this embodiment, the seeds of submerged plants are soaked with growth hormones, and after soaking, the seeds of submerged plants are distributed in the pores of ecological concrete, and mixed with biochar according to a weight ratio of ecological concrete to biochar of 2:3. The ecological concrete and biochar are wrapped together with biodegradable non-woven fabrics, and the required number of packages are wrapped. Then, the packages are thrown from the water surface and placed on the bottom layer of the ecological breeding system. Both biochar and ecological concrete are wrapped with biodegradable non-woven fabrics. Because the density of biochar is smaller than that of water, it can sink to the bottom of the water after being thrown from the water surface. The non-woven fabric will eventually degrade naturally in the later stage, and will not cause long-term impact on the environment. The pore structure of the ecological concrete can attach biochar, which can make the biochar stable at the bottom of the water.

[0022] Clams and snails participate in the decomposition and circulation of organic matter in the water by filtering or foraging for organic debris.

[0023] By feeding on organic debris and dead plant and animal remains, earthworms help decompose organic matter and promote the circulation of nutrients. Through their activities, they help increase the oxygen content of sediments and promote the diffusion of nutrients.

[0024] Chironomidae larvae are an important component of aquatic ecosystems and promote material circulation by feeding on organic debris and microorganisms.

[0025] Shrimp and crab disturb the sediments by foraging and burrowing in the sediments, which helps increase the material exchange between the sediments and the water body, thereby promoting the decomposition of organic matter; by eating organic debris and other microorganisms in the sediments, the excrement of shrimp and crabs is rich in nutrients, which can provide nutrition for the microorganisms in the sediments, promote their growth and activity, and accelerate the decomposition of organic matter; the activities of shrimp and crabs help improve the physical structure of the sediments, increase the aeration of the sediments, and provide a suitable living environment for aerobic microorganisms, thereby promoting the decomposition of organic matter.

[0026] The biochar in this example is converted from rice husk pyrolysis. These raw materials usually have low ecotoxicity and can produce high-quality biochar suitable for aquatic environments.

[0027] Submerged plants can absorb nutrients, including organic matter, from water bodies through their growth process, helping to reduce eutrophication of water bodies. Submerged plants can increase the concentration of dissolved oxygen in water bodies, promote the precipitation of suspended matter, inhibit the resuspension of sediments, and improve the transparency of water bodies.

[0028] Submerged plants are easier to fix in waters with slower currents. In places with faster currents, submerged plants may need stronger fixation mechanisms, such as more developed root systems or forming communities with other plants. Unstable rhizomes may prevent submerged plants from effectively absorbing nutrients from the bottom of the water, affecting their growth and development. Unstable rhizomes may make plants easily washed away or displaced by currents, reducing the coverage of underwater vegetation and the ability to provide habitats for fish and other aquatic life. Submerged plants purify water by absorbing nutrients and filtering suspended particles in the water. Unstable rhizomes will affect the water purification function of the plants.

[0029] Example 2

[0030] The present embodiment provides a multi-trophic level ecological aquaculture system suitable for freshwater fish farming. The ecological aquaculture system has multiple trophic levels, and the multiple trophic levels include at least fish trophic levels, filter-feeding shellfish trophic levels, and benthic organism trophic levels. The ecological aquaculture system also includes submerged plants. The bottom layer of the ecological aquaculture system is the benthic organism trophic level. The benthic organism trophic level includes ecological concrete and biochar. The biochar provides a habitat for benthic organisms, and the ecological concrete provides an activity space for benthic organisms. The porous structure of the ecological concrete fixes the submerged plants, and the porosity of the ecological concrete is 50%.

[0031] Benthic organisms include clams, snails, earthworms, midge larvae, shrimps and crabs.

[0032] The biochar in this embodiment is converted through the pyrolysis process of wood chips.

[0033] In this embodiment, the seeds of submerged plants are soaked with growth hormones, and after soaking, the seeds of submerged plants are distributed in the pores of ecological concrete, and the seeds are mixed with biochar according to a weight ratio of 2:3 between ecological concrete and biochar, and the ecological concrete and biochar are wrapped together with biodegradable non-woven fabrics, and the required number of packages are wrapped. Then, the packages are thrown from the water surface and placed on the bottom layer of the ecological breeding system. Both biochar and ecological concrete are wrapped with biodegradable non-woven fabrics. Because the density of biochar is smaller than that of water, it can sink to the bottom of the water after being thrown from the water surface. The non-woven fabric will eventually degrade naturally in the later stage, and will not cause long-term impact on the environment. The pore structure of the ecological concrete can attach biochar, can resist the buoyancy of the bottom of the water, and make the biochar stable at the bottom of the water.

[0034] Example 3

[0035] The present embodiment provides a multi-trophic level ecological aquaculture system suitable for freshwater fish farming. The ecological aquaculture system has multiple trophic levels, and the multiple trophic levels include at least fish trophic levels, filter-feeding shellfish trophic levels, and benthic organism trophic levels. The ecological aquaculture system also includes submerged plants. The bottom layer of the ecological aquaculture system is the benthic organism trophic level. The benthic organism trophic level includes ecological concrete and biochar. The biochar provides a habitat for benthic organisms, and the ecological concrete provides an activity space for benthic organisms. The porous structure of the ecological concrete fixes the submerged plants, and the porosity of the ecological concrete is 90%.

[0036] Benthic organisms include clams, snails, earthworms, midge larvae, shrimps and crabs.

[0037] The biochar of this embodiment is converted through the pyrolysis process of water hyacinth.

[0038] In this embodiment, the seeds of submerged plants are soaked with growth hormones, and after soaking, the seeds of submerged plants are distributed in the pores of ecological concrete, and the seeds are mixed with biochar according to a weight ratio of 2:3 between ecological concrete and biochar, and the ecological concrete and biochar are wrapped together with biodegradable non-woven fabrics, and the required number of packages are wrapped. Then, the packages are thrown from the water surface and placed on the bottom layer of the ecological breeding system. Both biochar and ecological concrete are wrapped with biodegradable non-woven fabrics. Because the density of biochar is smaller than that of water, it can sink to the bottom of the water after being thrown from the water surface. The non-woven fabric will eventually degrade naturally in the later stage, and will not cause long-term impact on the environment. The pore structure of the ecological concrete can attach biochar, can resist the buoyancy of the bottom of the water, and make the biochar stable at the bottom of the water.

[0039] Example 4

[0040] The present embodiment provides a multi-trophic level ecological aquaculture system suitable for freshwater fish farming. The ecological aquaculture system has multiple trophic levels, and the multiple trophic levels include at least fish trophic levels, filter-feeding shellfish trophic levels, and benthic organism trophic levels. The ecological aquaculture system also includes submerged plants. The bottom layer of the ecological aquaculture system is the benthic organism trophic level. The benthic organism trophic level includes ecological concrete, biochar and limestone. The biochar provides a habitat for benthic organisms, and the ecological concrete provides an activity space for benthic organisms. The porous structure of the ecological concrete fixes the submerged plants, and the porosity of the ecological concrete is 20%.

[0041] Benthic organisms include clams, snails, earthworms, midge larvae, shrimps and crabs.

[0042] The biochar of this embodiment is converted through the pyrolysis process of water hyacinth.

[0043] In this embodiment, the seeds of submerged plants are soaked with growth hormones, and after soaking, the seeds of submerged plants are distributed in the pores of ecological concrete, and mixed with biochar according to a weight ratio of ecological concrete to biochar of 2:3. The ecological concrete and biochar are wrapped together with biodegradable non-woven fabrics, and the required number of packages are mixed according to a weight ratio of ecological concrete to limestone of 2:1. Then, the wrapped material and limestone mixture are thrown from the water surface and placed on the bottom layer of the ecological breeding system. Both biochar and ecological concrete are wrapped with biodegradable non-woven fabrics. Because the density of biochar is smaller than that of water, it can sink to the bottom of the water after being thrown from the water surface. The non-woven fabric will eventually degrade naturally in the later stage, and will not cause long-term impact on the environment. The pore structure of the ecological concrete can attach biochar and resist the buoyancy of the bottom of the water, so that the biochar is stable at the bottom of the water.

[0044] The bottom layer of the ecological aquaculture system described in this embodiment is composed of ecological concrete, biochar and limestone. The function of limestone is to stabilize the pH value in the water body, prevent the decomposition of organic matter from producing CO2 and other organic acids and other reasons that cause fluctuations in the pH value of the water body.

[0045] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A multi-trophic level ecological breeding system suitable for freshwater fish breeding, characterized in that: The ecological aquaculture system has multiple nutrient levels, which include at least fish nutrient levels, filter-feeding shellfish nutrient levels, and benthic organism nutrient levels. The ecological aquaculture system also includes submerged plants, and is characterized in that the bottom layer of the ecological aquaculture system is the benthic organism nutrient level, and the benthic organism nutrient level includes ecological concrete and biochar, the biochar provides a habitat for benthic organisms, the ecological concrete provides an activity space for the benthic organisms, and the porous structure of the ecological concrete fixes the submerged plants.

2. A multi-trophic level ecological aquaculture system suitable for freshwater fish farming as claimed in claim 1, characterized in that: The porosity of the ecological concrete is at least above 20%.

3. A multi-trophic level ecological aquaculture system suitable for freshwater fish farming as claimed in claim 1, characterized in that: The benthic organisms include clams, snails, water earthworms, chironomid larvae, shrimps and crabs.

4. A multi-trophic level ecological aquaculture system suitable for freshwater fish farming as claimed in claim 1, characterized in that: The biochar is converted through a pyrolysis process, and the raw material of the biochar comes from one of agricultural waste, forestry waste or aquatic plants.

5. A multi-trophic level ecological aquaculture system suitable for freshwater fish aquaculture as claimed in claim 4, characterized in that: The agricultural waste is rice husk or straw; the forestry waste is wood chips or sawdust; and the aquatic plant is water hyacinth or algae.

6. The multi-trophic level ecological aquaculture system suitable for freshwater fish aquaculture according to claim 1, characterized in that: The bottom layer of the ecological breeding system is composed of ecological concrete, biochar and limestone.