Method and system for assessing environmental carrying capacity of net cage fish farming based on sedimentation flux

Abstract

The application discloses a net cage fish culture environment carrying capacity evaluation method and system based on sedimentation flux, and relates to the technical field of culture environment regulation and control. The method comprises a culture fish population biomass model, a relationship model between the sedimentation flux of the biological sediment in the net cage culture area and the culture fish population biomass, and an organic matter and inorganic matter decay model in the surface sediment. The method selects the organic carbon content in the surface sediment of the seabed as an environmental index, and according to the threshold value of the organic carbon content in the surface sediment, the stocking quantity of the culture fish capable of making the organic carbon content in the surface sediment reach the threshold value at the end of the culture period is predicted as the environmental carrying capacity of the net cage culture. The application can provide a direct basis for the production decision of the net cage fish culture, maintain a good water environment, and realize the sustainable development of the net cage culture industry.

Description

Technical Field

[0001] This invention relates to the field of aquaculture environment control technology, and in particular to a method and system for assessing the carrying capacity of cage fish aquaculture environment based on sedimentation flux. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Cage aquaculture is an important fish farming model, and feed-based cage aquaculture is one of the pillar industries of marine fish farming. With the expansion of farming scale and density, the aquatic environment of cage aquaculture is constantly deteriorating, affecting not only the effectiveness of cage aquaculture but also the environmental quality and ecological security of the cage aquaculture area and its adjacent waters. To reduce the negative effects of cage aquaculture on the environment of cage aquaculture areas and their adjacent waters, there is an urgent need to establish a simple, reliable, and universally applicable method for assessing the environmental carrying capacity of cage aquaculture that requires minimal environmental parameters, has stable limiting factors indicating environmental carrying capacity, and can guide aquaculture production planning, controlling the scale of cage aquaculture within the environmental carrying capacity of the aquaculture area.

[0004] The quality of the aquaculture environment declines with the increase in the scale or density of cage-cultured fish, such as a decrease in dissolved oxygen concentration and an increase in nutrient concentration. This deterioration in the aquaculture environment negatively impacts the fish, affecting their healthy growth, leading to decreased growth rates, disease outbreaks, and even large-scale mortality. Based on the health status of the farmed fish and the response of the aquaculture environment to the scale or density of the culture, the carrying capacity of cage aquaculture is currently assessed using several methods, including the relationship between the specific growth rate of farmed fish and stocking density, aquatic ecological dynamics, and the relationship between the organic matter content in surface sediments and the number of farmed fish. When determining the carrying capacity based on the relationship between the specific growth rate and stocking density of farmed fish, the stocking density at which the specific growth rate of farmed fish is 0 is generally taken as the maximum stocking density, i.e., the carrying capacity of the aquaculture environment. Because different farmed fish species have different growth rates, this method requires a relatively long experimental period to determine their growth rate. This method assumes that a specific growth rate of fish decreases with increasing stocking density, but in reality, the relationship between the specific growth rate and stocking density is not a simple linear one. Different fish species have different ecological habits, and both excessively high and low stocking densities can cause a decrease in their specific growth rate. Therefore, the carrying capacity of the aquaculture environment assessed by this method is influenced by the biological habits of the fish. Furthermore, methods relying on aquatic ecological dynamics to assess the carrying capacity of the aquaculture environment include box models, hydrodynamic models, and ecological dynamic models that couple hydrodynamic models with the ecological processes of the aquaculture system. These models use the concentration of dissolved oxygen or nutrients in the water within the cage aquaculture area as environmental indicators. Based on a certain national water quality standard, when the scale or density of fish farming reaches a certain value, causing dissolved oxygen to decrease to a certain water quality standard or nutrients to increase to a certain water quality standard, the carrying capacity of the aquaculture environment is determined. The main problem with this type of method is that the high fluidity of water bodies leads to drastic spatial and temporal changes in aquatic environmental factors. The environmental quality reflected by these rapidly changing environmental factors is unstable, and making decisions to adjust the scale or density of aquaculture based on the carrying capacity determined by this method carries significant risk. Furthermore, the organic matter content in seabed surface sediments varies with the scale or density of aquaculture. Establishing a regression relationship between the organic matter content in surface sediments and the number of fish in cage culture allows for determining the maximum number of fish cultured to reach a threshold organic matter content in the surface sediments—this is the carrying capacity. While this method is relatively simple and uses relatively stable environmental indicators, the regression relationship between sediment organic matter content and the number of fish in cage culture is affected by factors such as the topography of the aquaculture area, water flow velocity and water exchange cycle, temperature, and benthic community. In other words, this regression relationship varies depending on the aquaculture area, thus this method lacks universality and is difficult to predict the carrying capacity of aquaculture in different water bodies.

[0005] Therefore, how to provide a method for assessing the environmental capacity of cage aquaculture that does not require too many environmental parameters, has stable limiting factors indicating environmental carrying capacity, provides stable and reliable assessment results, has good universality, and is easy to implement, so as to provide a basis for cage aquaculture production decisions, avoid environmental pollution and water quality deterioration caused by excessive stocking of fish in cages, and avoid affecting the economic benefits of cage aquaculture, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for assessing the carrying capacity of cage aquaculture environments based on sedimentation flux. By constructing several models, the total amount of surface sediment and organic carbon mass in the seabed cage aquaculture area during the aquaculture cycle are obtained, thereby calculating the number of fish fry to be stocked as the carrying capacity of the cage aquaculture environment, providing a basis for cage aquaculture production decisions.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] The first aspect of this invention provides a method for assessing the carrying capacity of cage-cultured fish based on sedimentation flux, comprising the following steps:

[0009] Obtain biomass data of cultured fish populations in net cage aquaculture areas and construct biomass models of cultured fish populations;

[0010] Data on the biomass of cultured fish populations and the amount of fish feces and uneaten feed in the seabed surface were obtained in the cage aquaculture area, and a model was constructed to show the relationship between the sedimentation flux of biological sediments in the cage aquaculture area and the biomass of cultured fish populations.

[0011] Obtain data on the organic matter content of surface sediments, and establish decay models for organic matter and inorganic matter in surface sediments;

[0012] The daily residual organic and inorganic matter mass of the original surface sediment in the cage aquaculture area was calculated based on the decay models of organic matter and inorganic matter in the surface sediment.

[0013] The amount of fish feces and uneaten feed generated daily on the seabed surface in the cage aquaculture area was calculated based on the biomass model of the cultured fish population and the relationship model between sedimentation flux and the biomass of the cultured fish population.

[0014] The residual organic and inorganic matter mass of fish feces and uneaten feed produced daily in the seabed surface of the net cage aquaculture area was calculated using the decay models of organic matter and inorganic matter in surface sediments.

[0015] Summarize the daily residual organic and inorganic matter from the original surface sediments of the cage aquaculture area, and the daily residual organic and inorganic matter from fish feces and uneaten feed produced on the seabed surface of the cage aquaculture area, and calculate the organic carbon content.

[0016] The number of fish fry stocked at which the organic carbon content of the surface sediment in the cage culture area reaches a threshold at the end of the culture cycle is taken as the carrying capacity of the culture environment.

[0017] Furthermore, the sub-models of the biomass model for farmed fish populations include: a population decline model for farmed fish, a body length growth model, and a model of the relationship between body length and body mass.

[0018] Furthermore, a population decline model and a body length growth model are used to describe the decline pattern of the cultured population and the growth pattern of individual body length. A body length-body mass relationship model is used to convert body length into mass.

[0019] Furthermore, during the cage culture cycle, the biomass of the cultured fish population in the cage culture area and the amount of fish feces and uneaten feed in the seabed surface sediments are investigated monthly to obtain data on the biomass of the cultured fish population in the cage culture area and the amount of fish feces and uneaten feed in the seabed surface sediments.

[0020] Furthermore, based on the data characteristics of fish feces, uneaten feed, and cultured fish biomass on the seabed surface of the cage aquaculture area, a quantitative relationship between fish feces, uneaten feed, and cultured fish biomass per unit area on the seabed surface of the cage aquaculture area is established, thereby constructing a model of the relationship between sedimentation flux of biological sediments and cultured fish biomass in the cage aquaculture area.

[0021] Furthermore, the specific process of obtaining organic matter content data from surface sediments and establishing decay models for organic and inorganic matter in surface sediments is as follows:

[0022] Monthly surveys were conducted on the organic matter content in surface sediments of non-aquaculture areas in net cage aquaculture zones, and a decay model for organic matter in surface sediments was established.

[0023] Based on historical data and literature, a decay model of inorganic matter in surface sediments was constructed.

[0024] Furthermore, the specific steps for calculating the daily residual organic and inorganic matter mass of the original surface sediment in the net cage aquaculture area, based on the decay models of organic and inorganic matter in the surface sediment, are as follows:

[0025] Before stocking seedlings in net cage aquaculture, the mass of organic and inorganic matter in the surface sediments of the net cage aquaculture area is investigated as a baseline value. Using the baseline value as the starting point, the mass of organic and inorganic matter remaining in the original surface sediments of the seabed net cage aquaculture area each day is calculated based on the decay models of organic matter and inorganic matter in the surface sediments.

[0026] Furthermore, based on the biomass model of farmed fish populations and the relationship model between sedimentation flux and farmed fish population biomass, the specific steps for calculating the daily amount of fish feces and uneaten feed generated on the seabed surface of the net cage aquaculture area are as follows:

[0027] After cage culture begins, the daily biomass of the cultured fish population is calculated based on the biomass model of the cultured fish population.

[0028] The amount of fish feces and uneaten feed generated daily on the seabed surface in the cage aquaculture area was calculated based on the relationship model between the daily biomass and sedimentation flux of the cultured fish population and the biomass of the cultured fish population.

[0029] Furthermore, the specific steps for calculating the residual organic and inorganic matter mass of the daily amount of feces and uneaten feed generated on the seabed surface of the net cage aquaculture area, based on the decay models of organic and inorganic matter in surface sediments, are as follows:

[0030] Based on the organic matter content of fish feces and uneaten feed, the daily fish feces and uneaten feed are divided into two parts: organic matter and inorganic matter. According to the decay models of organic matter and inorganic matter in surface sediments, the residual organic matter and inorganic matter mass of the daily fish feces and uneaten feed produced on the seabed surface of the net cage aquaculture area are calculated in subsequent days.

[0031] Furthermore, the total mass of surface sediments in the cage aquaculture area is calculated by summing the daily residual organic and inorganic matter from the original surface sediments and the daily residual organic and inorganic matter from fish feces and uneaten feed produced on the seabed surface. The total mass of surface sediments in the cage aquaculture area is then calculated by summing the daily residual organic matter from the original surface sediments and the daily residual organic matter from fish feces and uneaten feed produced on the seabed surface. Based on the organic carbon content in the organic matter, the mass of organic carbon is calculated, and thus the organic carbon content of the surface sediments in the cage aquaculture area is determined.

[0032] A second aspect of the present invention provides a system for assessing the carrying capacity of cage-cultured fish based on sedimentation flux, comprising:

[0033] The model building module is configured to acquire biomass data of cultured fish populations in net cage aquaculture areas and build a biomass model of the cultured fish populations.

[0034] Data on the biomass of cultured fish populations and the amount of fish feces and uneaten feed in the seabed surface were obtained in the cage aquaculture area, and a model was constructed to show the relationship between the sedimentation flux of biological sediments in the cage aquaculture area and the biomass of cultured fish populations.

[0035] Obtain data on the organic matter content of surface sediments, and establish decay models for organic matter and inorganic matter in surface sediments;

[0036] The data processing module is configured to calculate the daily residual organic and inorganic matter mass of the original surface sediment in the cage aquaculture area based on the decay models of organic matter and inorganic matter in the surface sediment.

[0037] The amount of fish feces and uneaten feed generated daily on the seabed surface in the cage aquaculture area was calculated based on the biomass model of the cultured fish population and the relationship model between sedimentation flux and the biomass of the cultured fish population.

[0038] The residual organic and inorganic matter mass of fish feces and uneaten feed produced daily in the seabed surface of the net cage aquaculture area was calculated using the decay models of organic matter and inorganic matter in surface sediments.

[0039] The capacity calculation module is configured to summarize the residual organic and inorganic matter mass of the original surface sediments in the cage aquaculture area every day, and the residual organic and inorganic matter mass of the amount of fish feces and uneaten feed produced daily on the seabed surface of the cage aquaculture area, and calculate the organic carbon content.

[0040] The number of fish fry stocked at which the organic carbon content of the surface sediment in the cage culture area reaches a threshold at the end of the culture cycle is taken as the carrying capacity of the culture environment.

[0041] The above one or more technical solutions have the following beneficial effects:

[0042] This invention discloses a method for assessing the carrying capacity of cage-cultured fish based on sedimentation flux. The method encompasses three sub-models that essentially include the influence of aquatic topography, water flow, and benthic communities on the sedimentation and accumulation of biological sediments. Therefore, this method is universally applicable. The model construction does not require input of aquatic topography, flow field, or biological community elements; thus, the method's construction requires minimal environmental data, is simple in structure, and is easy to implement.

[0043] Based on the characteristics of organic carbon being stable and slowly decomposing in seabed surface sediments, this invention uses it as an environmental indicator. The estimated carrying capacity of cage-cultured fish is more reliable, providing a basis for cage-cultured production decisions and avoiding environmental pollution and water quality deterioration caused by excessive stocking of fish in cages, which would affect the economic benefits of cage-cultured fish farming.

[0044] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0045] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0046] Figure 1 This is a flowchart of the method for assessing the carrying capacity of cage fish farming environment based on sedimentation flux in Embodiment 1 of the present invention;

[0047] Figure 2 This is a graph showing the changes in the population size and biomass of cultured fish over time throughout the entire culture cycle, as described in Embodiment 1 of the present invention.

[0048] Figure 3 This is a graph showing the variation of organic matter content and organic carbon content in the sample plots starting from the baseline survey in Embodiment 1 of the present invention. Detailed Implementation

[0049] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0050] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0051] Example 1:

[0052] Embodiment 1 of the present invention provides a method for assessing the carrying capacity of cage-cultured fish based on sedimentation flux, such as... Figure 1 As shown, it includes the following steps:

[0053] Step 1: Obtain biomass data of the cultured fish population in the net cage aquaculture area and construct a biomass model of the cultured fish population;

[0054] Step 2: Obtain data on the biomass of farmed fish populations in the cage aquaculture area and the amount of fish feces and uneaten feed on the seabed surface, and construct a model of the relationship between the sedimentation flux of biological sediments in the cage aquaculture area and the biomass of farmed fish populations.

[0055] Step 3: Obtain the organic matter content data of surface sediments and establish decay models for organic matter and inorganic matter in surface sediments;

[0056] Step 4: Calculate the daily residual organic and inorganic matter mass of the original surface sediment in the net cage aquaculture area based on the decay models of organic and inorganic matter in the surface sediment.

[0057] Step 5: Calculate the amount of fish feces and uneaten feed generated daily on the seabed surface of the cage aquaculture area based on the biomass model of the cultured fish population and the relationship model between sedimentation flux and the biomass of the cultured fish population.

[0058] Step 6: Calculate the residual organic and inorganic matter mass of fish feces and uneaten feed produced daily in the seabed surface of the net cage aquaculture area using the decay models of organic and inorganic matter in surface sediments.

[0059] Step 7: Summarize the daily residual organic and inorganic matter from the original surface sediments in the cage aquaculture area, and the daily residual organic and inorganic matter from the amount of fish feces and uneaten feed produced on the seabed surface of the cage aquaculture area, and calculate the organic carbon content.

[0060] Step 8: The number of fish fry stocked at which the organic carbon content of the surface sediment in the net cage culture area reaches the threshold at the end of the culture cycle is taken as the carrying capacity of the culture environment.

[0061] Because the seabed area of ​​the cage aquaculture area is too large to be fully surveyed, in this embodiment, multiple square areas with a length of 1 meter and a width of 1 meter are set up as survey quadrats on the seabed of the cage aquaculture area. During the survey and sampling process, the average value of the data from multiple quadrats is taken as the result for the entire cage aquaculture area.

[0062] In step 1, based on literature or survey sampling, a population decline model, a body length growth model, and a body length-to-body weight relationship model for farmed fish populations are established, and a biomass model for farmed fish populations is constructed.

[0063] After fish fry are released into the net cages, the number of farmed fish will decrease over time due to diseases and other reasons, while the surviving fish will grow larger and larger. This embodiment uses the following population decline model and body length growth model to describe the decline law of the farmed population and the growth law of individual body length, and uses the following body length and body mass relationship model to convert body length into mass.

[0064] N t =n0e -ZΔt

[0065] L t =Linf(1-e -k(t-t0) )

[0066] W = awL bw ,

[0067] Where n0 is the number of fish fry stocked in the net cage, and N t Z represents the number of fish that survive Δt days after stocking, and Z represents the mortality coefficient of the farmed fish population (d). -1 );L t Let t be the body length of a fish of age d, Linf be the ultimate body length, and k be the growth rate (d). -1 ), where t0 is the age (d) corresponding to the fish's body length being 0; W is the mass of a fish with body length L; aw is the growth condition factor; and bw is the power exponent coefficient. In this embodiment, n0 is the quantity to be solved.

[0068] Based on the above three models, the biomass model of fish populations in net cage culture is obtained:

[0069] B t =an0e -ZΔt [Linf(1-e -k(t-t0) )] b ,

[0070] Among them, B t The total mass (g) of fish surviving Δt days after stocking.

[0071] In step 2, during the cage culture cycle, the biomass of the cultured fish population in the cage culture area and the amount of fish feces and uneaten feed in the surface sediment are investigated monthly to obtain data on the biomass of the cultured fish population in the cage culture area and the amount of fish feces and uneaten feed in the seabed surface.

[0072] During the aquaculture process, fish excrement and excess feed are deposited on the seabed surface. By investigating the amount of fish excrement and uneaten feed per unit area of ​​the seabed surface in the cage aquaculture area, as well as the biomass of the cultured fish population during the investigation period, the relationship between the amount of fish excrement and uneaten feed per unit area of ​​the seabed surface and the biomass of the cultured fish population is established. This leads to the construction of a model relating the sedimentation flux of biological sediments in the cage aquaculture area to the biomass of the cultured fish population.

[0073] This embodiment uses a quadratic polynomial to describe the quantitative relationship between the amount of fish feces and uneaten feed per unit area of ​​the seabed surface in the cage aquaculture area and the biomass of the cultured fish population, thereby constructing a model of the relationship between the sedimentation flux of biological sediments in the cage aquaculture area and the biomass of the cultured fish population.

[0074] The quantitative relationship between the amount of fish feces and uneaten feed per unit area of ​​the seabed surface in cage aquaculture areas and the biomass of farmed fish populations is described by the following formula:

[0075] m fecet =a1+b1B t +c1Bt 2

[0076] m feedt =a² + b²B t +c1B t 2 ,

[0077] Where, m fecet and m feedt These represent the amount of feces (g) and uneaten feed (g) produced on day t after stocking the fish fry, respectively. Parameter a i b i c i The value of (i = 1 or 2) varies depending on the month.

[0078] In step 3, the specific process of obtaining the organic matter content data of surface sediments and establishing the decay models of organic matter and inorganic matter in surface sediments is as follows:

[0079] (1) Monthly surveys were conducted on the organic matter content in the surface sediments of non-aquaculture areas in cage aquaculture zones, and a decay model of organic matter in surface sediments was established.

[0080] For a specific nearshore cage aquaculture area, surface sediment samples are collected monthly from adjacent non-cage aquaculture areas to measure organic matter content, thus establishing a decay model for organic matter in the surface sediments. This embodiment uses the following model to express the decay law of organic matter mass over time.

[0081] mog t =mog0e -kogΔt ,

[0082] Where mog0 is the initial mass of the organic matter, in grams; mog t Δt represents the mass of organic matter remaining after Δt days; kog represents the rate of decay of organic matter (d). -1 ).

[0083] (2) Based on historical data and literature, construct a decay model of inorganic matter in surface sediments;

[0084] The inorganic matter in seabed surface sediments deteriorates in quality due to factors such as element precipitation. In this embodiment, the following model is used to describe the decay law of inorganic matter in surface sediments.

[0085] miog t =miog0e -kiogΔt ,

[0086] miog0 is the initial mass of the inorganic substance, expressed in grams; miog t Δt represents the mass of inorganic matter remaining after Δt days; kiog represents the rate of decay of inorganic matter (d).-1 The determination can be made based on historical data and literature.

[0087] In step 4, the specific steps for calculating the daily residual organic and inorganic matter mass of the original surface sediment in the net cage aquaculture area based on the decay models of organic and inorganic matter in the surface sediment are as follows:

[0088] Before stocking the cage culture, the mass of organic and inorganic matter in the surface sediments of the seabed surface cage culture area is investigated as the baseline value. Using the baseline value as the starting point, the mass of organic and inorganic matter remaining in the original surface sediments of the cage culture area each day is calculated based on the decay models of organic matter and inorganic matter in the surface sediments.

[0089] In this embodiment, a 1m² area at a depth of 10cm was selected from the seabed surface of the cage aquaculture area. 2 The area is designated as a quadrat. Sediments within the quadrat are collected, and the total mass and organic matter mass of the sediments in the quadrat are measured. The organic matter mass is subtracted from the total sediment mass to obtain the inorganic matter mass of the quadrat sediments. The sampling time is set at one month before the seedlings are placed in the net cage. Starting from this point, the daily residual organic and inorganic matter mass of the original sediments in the quadrat is calculated according to the model in step 3.

[0090] In step 5, the specific steps for calculating the daily amount of fish feces and uneaten feed generated on the seabed surface of the net cage aquaculture area based on the biomass model of the cultured fish population and the relationship model between sedimentation flux and the biomass of the cultured fish population are as follows:

[0091] (1) After cage culture begins, the daily biomass of the cultured fish population is calculated based on the biomass model of the cultured fish population:

[0092] Given the total stocking quantity n0 of farmed fish fry in the net cage culture area, the biomass (g) of the farmed fish population can be calculated for each subsequent day in the biomass model of farmed fish population.

[0093] (2) Calculate the amount of fish feces and uneaten feed generated daily on the seabed surface of the cage aquaculture area based on the relationship model between the daily biomass and sedimentation flux of the cultured fish population and the biomass of the cultured fish population.

[0094] Specifically, the daily biomass of farmed fish populations in (1) is substituted into the relationship model between sedimentation flux and biomass of farmed fish populations to calculate the amount of fish feces and uneaten feed generated daily in the quadrat in step 4.

[0095] In step 6, based on the decay models of organic matter and inorganic matter in the surface sediments in step 3, the daily residual organic matter and inorganic matter mass of fish feces and uneaten feed in step 5 are calculated.

[0096] Fish feces and uneaten food each contain a certain proportion of organic matter. Based on the organic matter content of fish feces and uneaten food, the mass of organic matter in the daily amount of fish feces and uneaten food produced can be calculated. Subtracting the respective mass of organic matter from the amount of fish feces and uneaten food produces the mass of inorganic matter in the daily amount of fish feces and uneaten food produced.

[0097] Based on the decay models of organic and inorganic matter in surface sediments, the daily residual organic and inorganic matter masses of fish feces and uneaten feed were calculated.

[0098] In step 7, the organic carbon content is calculated by summing the daily residual organic and inorganic matter from the original surface sediments in the cage aquaculture area, as well as the daily residual organic and inorganic matter from fish feces and uneaten feed produced on the seabed surface of the cage aquaculture area.

[0099] In this embodiment, in a depth of 10cm and an area of ​​1m 2 Within the sample plot, the sediment includes the daily residue of the original sediment before cage culture, the daily fish feces and uneaten feed produced after the start of cage culture, and the residue of fish feces and uneaten feed produced earlier. The amount of fish feces and uneaten feed produced on a given day is considered 100% of the residue. Therefore, by summing the daily residue of the original sediment and the daily residue of fish feces and uneaten feed produced, the total daily sediment mass within the sample plot is obtained.

[0100] Based on steps 4 and 6, the original sediment and fish feces and uneaten food are divided into organic and inorganic components. Therefore, by summing the daily residual organic and inorganic matter from the original sediment and the daily residual organic and inorganic matter from the feces and uneaten food produced in the plot, the total daily sediment mass in the plot is obtained. Similarly, by summing the daily residual organic matter from the original sediment and the daily residual organic matter from the feces and uneaten food produced in the plot, the daily organic matter mass in the plot is obtained. Based on the organic carbon content in the organic matter, the mass of organic carbon in the plot is calculated. Finally, the organic carbon content is calculated by dividing the mass of organic carbon in the plot by the total mass of sediment in the plot.

[0101] In step 8, the number of fish fry stocked at which the organic carbon content of the surface sediment in the cage culture area reaches the threshold at the end of the culture cycle is taken as the carrying capacity of the culture environment.

[0102] In the Class I marine sediment quality standards of the People's Republic of China, the maximum limit for organic carbon is 2.0%. For safety reasons, in this embodiment, the threshold for organic carbon is set at 1.8%, meaning that at the end of the aquaculture cycle, the mass of organic carbon in the sample plot can only increase to 1.8% of the total mass of sediment in the plot. The number of fish fry stocked in the net cage aquaculture area is adjusted so that the organic carbon content in the sample plot reaches 1.8% at the end of the aquaculture cycle. The resulting number of fish fry stocked is the maximum number of fry stocked, which is also the carrying capacity of the aquaculture environment in the net cage aquaculture area.

[0103] In this embodiment, a baseline survey of the cage aquaculture area was conducted on June 1st, with a depth of 10cm and an area of ​​1m². 2 The total mass of sediment in the sample plot was 2208.27g, of which 34.45g was organic matter and 2173.82g was inorganic matter. The seedlings were released on July 1 to start cage culture production. Cage culture ended on November 3 and all the fish raised were sold.

[0104] The parameters for the population decline model, body length growth model, and body length-to-body weight relationship model of farmed fish are Z = 0.0031d. -1 , aw=0.0252, bw=3.1105, Linf=174.8cm, k=0.0008d -1 t0 = -41.7d.

[0105] Table 1 shows the parameter values ​​for the quantitative relationship between the amount of fish feces and uneaten feed per unit area of ​​the seabed surface in the cage aquaculture area and the biomass of the cultured fish population.

[0106] Table 1. Model parameters relating fish feces, uneaten feed, and farmed fish biomass.

[0107] month a1 b1 c1 a2 b2 c2 7 3.9511 -1.0×10-8 2.0×10-17 0.0672 3.0×10-10 1.0×10-18 8 -0.9047 2.0×10-9 1.0×10-18 0.2005 -4.0×10-10 5.0×10-19 9 0.6404 -8.0×10-10 2.0×10-18 0.1185 -1.0×10-10 4.0×10-19 10 0.7501 -7.0×10-10 1.0×10-18 -0.6350 9.0×10-10 2.0×10-19 11 -1.7685 2.0×10-9 1.0×10-18 0.0313 -5.0×10-11 4.0×10-19

[0108] In the decay models for organic and inorganic matter on the seabed surface, the decay rate of organic matter is taken as kog = 0.0011d. -1 The decay rate of organic matter is taken as kiog = 0.0003d. -1 .

[0109] The organic matter content in fish feces and uneaten feed was 37.27% and 83.19%, respectively. The organic carbon content in the organic matter was 49%.

[0110] Based on the above parameters, the calculated carrying capacity of the aquaculture area is 14,967,176.00 fish, and the total weight of marketable fish at the end of the aquaculture cycle is 4,662,318.80 kg. When initially stocked with 14,967,176.00 fry... Figure 2 It describes the changes in the population size and biomass of farmed fish over time throughout the entire aquaculture cycle. Figure 3 It shows the changing patterns of organic matter and organic carbon content within the sample plots, starting from the baseline survey.

[0111] Example 2:

[0112] Embodiment 2 of the present invention provides a system for assessing the carrying capacity of cage-cultured fish based on sedimentation flux, comprising:

[0113] The model building module is configured to acquire biomass data of cultured fish populations in net cage aquaculture areas and build a biomass model of the cultured fish populations.

[0114] Data on the biomass of cultured fish populations and the amount of fish feces and uneaten feed in the seabed surface were obtained in the cage aquaculture area, and a model was constructed to show the relationship between the sedimentation flux of biological sediments in the cage aquaculture area and the biomass of cultured fish populations.

[0115] Obtain data on the organic matter content of surface sediments, and establish decay models for organic matter and inorganic matter in surface sediments;

[0116] The data processing module is configured to calculate the daily residual organic and inorganic matter mass of the original surface sediment in the cage aquaculture area based on the decay models of organic matter and inorganic matter in the surface sediment.

[0117] The amount of fish feces and uneaten feed generated daily on the seabed surface in the cage aquaculture area was calculated based on the biomass model of the cultured fish population and the relationship model between sedimentation flux and the biomass of the cultured fish population.

[0118] The residual organic and inorganic matter mass of fish feces and uneaten feed produced daily in the seabed surface of the net cage aquaculture area was calculated using the decay models of organic matter and inorganic matter in surface sediments.

[0119] The capacity calculation module is configured to summarize the residual organic and inorganic matter mass of the original surface sediments in the cage aquaculture area every day, and the residual organic and inorganic matter mass of the amount of fish feces and uneaten feed produced daily on the seabed surface of the cage aquaculture area, and calculate the organic carbon content.

[0120] The number of fish fry stocked at which the organic carbon content of the surface sediment in the cage culture area reaches a threshold at the end of the culture cycle is taken as the carrying capacity of the culture environment.

[0121] The above Embodiment 2 corresponds to Embodiment 1. For specific implementation details, please refer to the relevant explanatory section of Embodiment 1.

[0122] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0123] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for assessing the carrying capacity of cage-cultured fish based on sedimentation flux, characterized in that, Includes the following steps: Obtain biomass data of cultured fish populations in net cage aquaculture areas and construct biomass models of cultured fish populations; Data on the biomass of cultured fish populations and the amount of fish feces and uneaten feed in the seabed surface were obtained in the cage aquaculture area, and a model was constructed to show the relationship between the sedimentation flux of biological sediments in the cage aquaculture area and the biomass of cultured fish populations. Obtain data on the organic matter content of surface sediments, and establish decay models for organic matter and inorganic matter in surface sediments; The daily residual organic and inorganic matter mass of the original surface sediment in the cage aquaculture area was calculated based on the decay models of organic matter and inorganic matter in the surface sediment. The amount of fish feces and uneaten feed generated daily on the seabed surface in the cage aquaculture area was calculated based on the biomass model of the cultured fish population and the relationship model between sedimentation flux and the biomass of the cultured fish population. The sub-models of the biomass model for cultured fish populations include: a population decline model for cultured fish populations, a body length growth model, and a model of the relationship between body length and body mass. A population decline model and a body length growth model are used to describe the decline pattern of the cultured population and the growth pattern of individual body length. A body length-to-body mass relationship model is used to convert body length into mass. N t = n 0e -ZΔt L t = Linf (1-e -k(t-t0) ) W = awL bw ， in, n 0 represents the number of fish fry released into the net cage. N t The number of animals that survived Δt days after being released. Z The mortality rate of farmed fish populations; L t The body length of a t-year-old fish. Linf For the maximum body length, k For growth rate, t 0 represents the age corresponding to a fish's body length of 0; W Body length L The quality of the fish aw Growth condition factors, bw The power coefficient is the coefficient of the power. n 0 represents the quantity to be solved; Based on the above three models, the biomass model of fish populations in net cage culture is obtained: B t = awn 0e -ZΔt [ Linf (1-e -k(t-t0) )] bw ， in, B t The total mass of fish that survive Δt days after stocking; The residual organic and inorganic matter mass of fish feces and uneaten feed produced daily in the seabed surface of the net cage aquaculture area was calculated using the decay models of organic matter and inorganic matter in surface sediments. Summarize the daily residual organic and inorganic matter from the original surface sediments of the cage aquaculture area, and the daily residual organic and inorganic matter from fish feces and uneaten feed produced on the seabed surface of the cage aquaculture area, and calculate the organic carbon content. The number of fish fry stocked at which the organic carbon content of the surface sediment in the cage culture area reaches a threshold at the end of the culture cycle is taken as the carrying capacity of the culture environment.

2. The method for assessing the carrying capacity of cage-cultured fish based on settling flux as described in claim 1, characterized in that, A population decline model and a body length growth model are used to describe the decline pattern of the cultured population and the growth pattern of individual body length. A body length-body mass relationship model is used to convert body length into mass.

3. The method for assessing the carrying capacity of cage-cultured fish based on sedimentation flux as described in claim 1, characterized in that, During the cage culture cycle, the biomass of the cultured fish population in the cage culture area and the amount of fish feces and uneaten feed in the seabed surface sediments are investigated monthly to obtain data on the biomass of the cultured fish population in the cage culture area and the amount of fish feces and uneaten feed in the seabed surface sediments.

4. The method for assessing the carrying capacity of cage-cultured fish based on settling flux as described in claim 3, characterized in that, Based on the data characteristics of fish feces, uneaten feed, and cultured fish biomass in the seabed surface of cage aquaculture areas, a quantitative relationship between fish feces, uneaten feed, and cultured fish biomass per unit area of ​​the seabed surface of cage aquaculture areas is established, thereby constructing a model of the relationship between sedimentation flux of biological sediments and cultured fish biomass in cage aquaculture areas.

5. The method for assessing the carrying capacity of cage-cultured fish based on settling flux as described in claim 1, characterized in that, The specific process for obtaining organic matter content data from surface sediments and establishing decay models for organic and inorganic matter in surface sediments is as follows: Monthly surveys were conducted on the organic matter content in surface sediments of non-aquaculture areas in net cage aquaculture zones, and a decay model for organic matter in surface sediments was established. Based on historical data and literature, a decay model of inorganic matter in surface sediments was constructed. or, The specific steps for calculating the residual organic and inorganic matter mass of fish feces and uneaten feed produced daily in the seabed surface of the net cage aquaculture area, based on the decay models of organic and inorganic matter in surface sediments, are as follows: Based on the organic matter content of fish feces and uneaten feed, the daily fish feces and uneaten feed are divided into two parts: organic matter and inorganic matter. According to the decay models of organic matter and inorganic matter in surface sediments, the residual organic matter and inorganic matter mass of the daily fish feces and uneaten feed produced on the seabed surface of the net cage aquaculture area are calculated in subsequent days.

6. The method for assessing the carrying capacity of cage-cultured fish based on settling flux as described in claim 1, characterized in that, The specific steps for calculating the daily residual organic and inorganic matter mass of the original surface sediment in the net cage aquaculture area based on the decay models of organic and inorganic matter in surface sediments are as follows: Before stocking the cage culture, the quality of organic and inorganic matter in the surface sediments of the cage culture area on the seabed is investigated as the baseline value. Starting from the baseline value, and based on the decay models of organic and inorganic matter in the surface sediments, the daily residual organic and inorganic matter mass of the original surface sediments in the cage aquaculture area is calculated.

7. The method for assessing the carrying capacity of cage-cultured fish based on settling flux as described in claim 1, characterized in that, The specific steps for calculating the daily amount of fish feces and uneaten feed generated on the seabed surface in net cage aquaculture areas, based on the biomass model of cultured fish populations and the relationship model between sedimentation flux and cultured fish population biomass, are as follows: After cage culture begins, the daily biomass of the cultured fish population is calculated based on the biomass model of the cultured fish population. The amount of fish feces and uneaten feed generated daily on the seabed surface in the cage aquaculture area was calculated based on the relationship model between the daily biomass and sedimentation flux of the cultured fish population and the biomass of the cultured fish population.

8. The method for assessing the carrying capacity of cage-cultured fish based on settling flux as described in claim 1, characterized in that, The total mass of the surface sediments in the cage aquaculture area is calculated by summing the daily residual organic and inorganic matter from the original surface sediments and the daily residual organic matter from fish feces and uneaten feed produced on the seabed surface. The total organic matter mass of the surface sediments is then calculated based on the organic carbon content within the organic matter, and finally, the organic carbon content of the surface sediments in the cage aquaculture area is calculated.

9. An assessment system for the environmental carrying capacity assessment method for cage fish farming based on sedimentation flux as described in any one of claims 1-8, characterized in that, include: The model building module is configured to acquire biomass data of cultured fish populations in net cage aquaculture areas and build a biomass model of the cultured fish populations. Data on the biomass of cultured fish populations and the amount of fish feces and uneaten feed in the seabed surface were obtained in the cage aquaculture area, and a model was constructed to show the relationship between the sedimentation flux of biological sediments in the cage aquaculture area and the biomass of cultured fish populations. Obtain data on the organic matter content of surface sediments, and establish decay models for organic matter and inorganic matter in surface sediments; The data processing module is configured to calculate the daily residual organic and inorganic matter mass of the original surface sediment in the cage aquaculture area based on the decay models of organic matter and inorganic matter in the surface sediment. The amount of fish feces and uneaten feed generated daily on the seabed surface in the cage aquaculture area was calculated based on the biomass model of the cultured fish population and the relationship model between sedimentation flux and the biomass of the cultured fish population. The residual organic and inorganic matter mass of fish feces and uneaten feed produced daily in the seabed surface of the net cage aquaculture area was calculated using the decay models of organic matter and inorganic matter in surface sediments. The capacity calculation module is configured to summarize the residual organic and inorganic matter mass of the original surface sediments in the cage aquaculture area every day, and the residual organic and inorganic matter mass of the amount of fish feces and uneaten feed produced daily on the seabed surface of the cage aquaculture area, and calculate the organic carbon content. The number of fish fry stocked at which the organic carbon content of the surface sediment in the cage culture area reaches a threshold at the end of the culture cycle is taken as the carrying capacity of the culture environment.

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