Rare and endangered fish water quality standard derivation method

Abstract

The invention relates to the technical field of water quality benchmark prediction, in particular to a valuable, rare and endangered fish water quality benchmark derivation method which comprises the following steps: performing habitat investigation, biological investigation and pollutant investigation, and dividing a water area and pollutants; acquiring pollutant exposure data, pollutant toxicity data, tested biological information and related water quality parameter data; according to a principle and a priority evaluation principle, screening toxicity data of the pollutants on different tested organisms; calculating the hazard concentration of the species by adopting an SSD (Solid State Disk) method, otherwise, determining a final toxicity value by adopting a toxicity percentage sorting method; and deducing a short-term water quality standard, a long-term water quality standard and a tissue residue standard according to calculation results of the SSD method and the toxicity percentage sorting method. According to the method, water quality standard derivation can be carried out on rare and endangered fishes, and technical support is provided for rare and endangered fish research.

Description

Technical Field

[0001] The invention relates to the technical field of water quality benchmark prediction, and in particular to a method for deriving water quality benchmarks for rare and endangered fish. Background Art

[0002] Water quality benchmark refers to the maximum concentration or level of pollutants or harmful factors in the water environment that do not have a harmful effect on human health or aquatic ecosystems. Water quality benchmarks for rare and endangered fish refer to the maximum concentration or level of pollutants or harmful factors in the water environment that do not have a harmful effect on rare and endangered fish and their ecological functions, including short-term water quality benchmarks, long-term water quality benchmarks and organizational benchmarks.

[0003] The short-term water quality benchmark refers to the maximum concentration or level of pollutants or harmful factors in water bodies that does not produce acute harmful effects on rare and endangered fish and their ecological functions; the long-term water quality benchmark refers to the maximum concentration or level of pollutants or harmful factors in water bodies that does not produce chronic harmful effects on rare and endangered fish and their ecological functions; the tissue benchmark is the maximum concentration or level of pollutants or harmful factors in organisms that does not produce chronic harmful effects on rare and endangered fish and their ecological functions.

[0004] For example, a Chinese patent with publication number CN107991452A discloses a method for deriving an acute water quality benchmark for freshwater aquatic animals, including the following steps: a. Collection and screening of acute toxicity data; b. Sequentially obtain the average acute value and the corresponding cumulative probability of the screened acute toxicity data; c. Use the natural logarithm of the average acute value obtained in step b as the horizontal coordinate X, and the corresponding cumulative probability P as the vertical coordinate Y to construct a cubic spline function S(x), assign a value to Y, and obtain a corresponding X value, take the antilogarithm of X, and obtain the short-term hazardous concentration STHC100Y, which is the acute water quality benchmark value for the target pollutant. The above-mentioned derivation method of the acute water quality benchmark for freshwater aquatic animals provides a good technical support for various studies on fish.

[0005] However, the current water quality benchmark limits are all safety thresholds for common organisms or fish, and there are no standards for rare and endangered fish. For example, the standard limits for copper in Class I and Class II water bodies are 0.01 mg / L and 1 mg / L, respectively, which are equivalent to or higher than the concentration values ​​that cause chronic toxicity to the Chinese sturgeon, and cannot provide effective protection for the Chinese sturgeon. Summary of the invention

[0006] In order to solve the problem of lack of water quality benchmarks for rare and endangered fish, the present invention provides a method for deriving water quality benchmarks for rare and endangered fish.

[0007] The present invention provides a method for deriving water quality standards for rare and endangered fish, which adopts the following technical solutions:

[0008] A method for deriving water quality benchmarks for rare and endangered fishes comprises the following steps:

[0009] Conduct habitat surveys, biological surveys, and pollutant surveys, and divide water areas and pollutants;

[0010] Obtain pollutant exposure data, pollutant toxicity data, test organism information and relevant water quality parameter data;

[0011] Screen the toxicity data of pollutants to different test organisms according to pre-established principles and priority evaluation principles;

[0012] The SSD method was used to calculate species hazard concentrations;

[0013] Short-term water quality standards, long-term water quality standards and tissue residue standards are derived based on the calculation results of the SSD method.

[0014] In a specific feasible implementation plan, the SSD method is preferably used to calculate the species hazard concentration, and the HC5 corresponding to the cumulative frequency of 5% is used to derive the water quality benchmark;

[0015] When the SSD method is used to calculate species hazard concentrations, the probability P value of the SSD method is calculated. If the probability P values ​​of all SSD models are less than 0.05, the toxicity percentage ranking method is used to determine the final toxicity value, and then the short-term water quality benchmark, long-term water quality benchmark and tissue residue benchmark are derived.

[0016] In a specific embodiment, before calculating the final toxicity value by the toxicity percentage ranking method, the average acute value and the average chronic value are calculated, wherein the calculation formula of the average acute value is:

[0017]

[0018] In the above formula, SMCV is the mean acute value;

[0019] SMCV is the species mean acute value;

[0020] j is the jth rare and endangered fish species, dimensionless;

[0021] k is the type of acute toxic effect;

[0022] n is the number of SMAVs, in units;

[0023] For the same genus, the smaller GMAV between the growth GMAV and the survival GMAV was taken into the subsequent calculation of the toxicity percentage ranking method. If only one GMAV was obtained, it was directly included in the subsequent calculation;

[0024] The calculation formula of the average chronic value is:

[0025]

[0026] In the above formula, GMCV is the average chronic value;

[0027] SMCV is the species mean chronic value;

[0028] z is the zth chronic toxic effect;

[0029] q is the number of SMCVs;

[0030] For the same genus, if multiple GMCVs were obtained based on different chronic toxic effects, the smallest GMCV was included in the subsequent calculations; if only one GMCV was obtained, it was directly included in the subsequent calculations.

[0031] In a specific feasible implementation scheme, when the final toxicity value is determined by the toxicity percentage ranking method, the final acute value FAV, the final chronic value FCV, and the final residual value FRV are calculated. The final acute value is extrapolated by the assessment factor to obtain the short-term water quality benchmark, the final chronic value is extrapolated by the assessment factor to obtain the long-term water quality benchmark, and the final residual value is extrapolated by the assessment factor to obtain the tissue benchmark.

[0032] In a specific embodiment, the calculation method of the final toxicity value and the calculation method of the final acute value FAV are:

[0033] Sort lg GMAV from small to large, determine its rank R, and calculate the cumulative frequency F of each genus R ;

[0034] Select multiple GMAVs with cumulative probabilities close to 0.05 and calculate FAV based on the cumulative frequency; the calculation formula is as follows:

[0035]

[0036] FAV=e A

[0037] In the above formula, S 2 is the variance of ln GMAV;

[0038] S is the standard deviation of ln GMAV;

[0039] GMAV is the mean acute value;

[0040] L and A are both intermediate calculated values;

[0041] If the species mean acute value SMAV of rare and endangered fish is lower than the FAV value, the species SMAV shall be used instead of the FAV value;

[0042] The final chronic value FCV and the final residual value FRV respectively use the chronic toxicity data based on water concentration-effect and the chronic toxicity data based on tissue concentration-effect, and the calculation method is the same as the calculation method of the final acute value FAV.

[0043] In a specific implementation plan, the water area and pollutants are divided as follows:

[0044] Through habitat surveys and biological surveys, the proposed research waters are divided into common habitat waters and special breeding waters;

[0045] According to the pollutant survey, if BAF≤2000, it is a non-bioaccumulative pollutant;

[0046] 2000<BAF≤5000, it is a bioaccumulative pollutant;

[0047] BAF>5000, which is a highly bioaccumulative pollutant.

[0048] In a specific feasible implementation scheme, when screening pollutant toxicity data, the pollutant toxicity data are divided into acute toxicity data and chronic toxicity data. The acute toxicity data are toxicity data based on water body concentration-effect, including toxic effects on growth and survival. The chronic toxicity data are toxicity data based on water body concentration-effect and toxicity data based on tissue concentration-effect, including toxic effects on growth, development, nerves, reproduction and survival.

[0049] In a specific feasible implementation plan, the pre-established principles are:

[0050] The model input data should be quality assessed and quality controlled, and should be relevant to the target species and environmental conditions. The input data should include the tested species, tested life stages, toxicity endpoints, water quality parameters, pollutant structure, and physical and chemical properties of the pollutants.

[0051] The error between the model prediction results and the existing experimental data is within the allowable range;

[0052] When multiple prediction results for the same species or toxicity endpoint differ too much, outliers are removed;

[0053] For data that appear abnormal in the prediction results or differ greatly from the existing experimental data, a judgment is made based on the scope of application of the model and the actual ecosystem conditions, and some or all of the data are discarded.

[0054] In a specific implementation scheme, before calculating the species hazard concentration by the SSD method, the species average acute value and the species average chronic value are calculated, wherein the calculation formula of the species average acute value is:

[0055]

[0056] In the above formula, SMAV is the species mean acute value;

[0057] i represents the i-th rare and endangered fish species;

[0058] l is the type of acute toxic effect;

[0059] m is the number of ATVs;

[0060] ATV is the acute toxicity value;

[0061] For the same species, the smaller SMAV between the growth SMAV and the survival SMAV was taken into the subsequent SSD calculation. If only one SMAV was obtained, it was directly included in the subsequent calculation.

[0062] The calculation formula for the average chronic value is:

[0063]

[0064] In the above formula, SMCV is the species mean chronic value;

[0065] i is the i-th rare and endangered fish;

[0066] z is the zth chronic toxic effect;

[0067] p is the number of CTVs;

[0068] CTV is the chronic toxicity value;

[0069] For the same species, if multiple SMCVs were obtained based on different chronic toxic effects, the smallest SMCV was included in the subsequent SSD method calculations; if only one SMCV was obtained, it was directly included in the subsequent calculations.

[0070] In summary, the present invention has the following beneficial effects:

[0071] A water quality benchmark derivation method for rare and endangered fish has been constructed to more accurately control the water quality of waters where rare and endangered fish live and reproduce, and to better protect rare and endangered fish. By combining the SSD algorithm and the toxicity percentage ranking method, a more accurate water quality benchmark can be derived and established. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a flow chart of the method for deriving water quality benchmarks for rare and endangered fish species.

[0073] Figure 2 It is a flow chart for obtaining data for deriving water quality benchmarks for rare and endangered fish species.

[0074] Figure 3 It is a flowchart of steps S100-S400.

[0075] Figure 4 It is a flowchart of steps S400-S700. DETAILED DESCRIPTION

[0076] The following is combined with Figure 1-4 The present invention is described in further detail.

[0077] The method for deriving water quality benchmarks for rare and endangered fish species includes the following steps:

[0078] S100, environmental survey.

[0079] The survey content includes habitat survey, biological survey and pollutant survey. Because rare and endangered fish have different requirements for water areas for habitat and reproduction, the proposed research waters are divided into common habitat waters and special breeding waters through habitat survey and biological survey, which is convenient for the subsequent formulation of different water quality benchmarks.

[0080] Through pollutant surveys, pollutants are divided into non-bioaccumulative pollutants, bioaccumulative pollutants and highly bioaccumulative pollutants. Furthermore, if the bioaccumulation factor (BAF) is ≤2000, it is a non-bioaccumulative pollutant; if 2000<BAF≤5000, it is a bioaccumulative pollutant; if BAF>5000, it is a highly bioaccumulative pollutant.

[0081] Habitat surveys mainly focus on the habitats of rare and endangered fish, including habitat characteristics, hydrological characteristics, physical characteristics, chemical characteristics, etc.

[0082] Biological surveys mainly focus on rare and endangered fish, including basic information, biological groups, biological characteristics, food (bait organisms) composition, ecological distribution, and ecological functions.

[0083] Pollutant surveys mainly focus on target pollutants, including basic information, physical and chemical properties, bioaccumulation potential, etc.

[0084] S200, data acquisition.

[0085] Obtain pollutant exposure data, pollutant toxicity data, test organism information and related water quality parameter data. Pollutant exposure data includes sampling information, sample analysis information, exposure data type and data source, etc. Among them, sampling information includes: the river basin, station name, station latitude and longitude, sampling time, sampling medium, etc. Sample analysis information includes concentration value, analysis method, etc. Exposure data types include water concentration, sediment concentration, organism concentration, etc.

[0086] Pollutant toxicity data include test conditions, test results and data sources, etc. Among them, test conditions include test type, test location, test method, purity of test substance, exposure mode (flow-through, semi-static, static), test load, exposure concentration (measured, theoretical), test matrix (fresh water, sea water, etc.), test design (control group, parallel group, number of test groups, etc.), solvent information (name and concentration of cosolvent, emulsifier, dispersant, etc.), test water quality parameters (temperature, pH, hardness, dissolved oxygen, organic matter content, suspended solids content, etc.), light intensity, light-dark ratio, etc. Test results include exposure time, toxicity endpoint, effect index, effect concentration, etc.

[0087] The information of the tested organisms includes the Chinese and Latin names of the tested fish, taxonomic status, biological origin, age, length, weight, sex, exposed life stage, habitat characteristics, geographical distribution area, living habits, etc. The relevant water quality parameter data are relevant water quality parameters of my country's surface water, such as: temperature, pH, hardness, organic matter content, suspended particulate matter content, monitoring time, monitoring area or site information, etc.

[0088] Since there are few toxicity studies directly using rare and endangered fish as test organisms, when research data are insufficient, alternative biological toxicity tests and model prediction methods (such as the QSAR-ICE model) can be used to obtain toxicity data of target pollutants to rare and endangered fish.

[0089] The sources of data may be domestic and international biological toxicity databases with clear sources, peer-reviewed publicly published literature or reports, official relevant data, data from other sources judged reliable by experts, and pollutant toxicity data that supplements testing and predictions during the benchmark derivation process.

[0090] S300, data screening.

[0091] Toxicity data are classified into acute toxicity data and chronic toxicity data. Acute toxicity data are toxicity data based on water concentration-effect, including two types of toxic effects: growth (weight, body length, growth rate, etc.) and survival (survival rate, mortality rate).

[0092] The chronic toxicity data consists of two parts: water concentration-effect toxicity data and tissue concentration-effect toxicity data. The toxic effects include growth (weight, body length, growth rate, etc.), development (deformity rate, teratogenicity index, etc.), nerves (feeding behavior, avoidance behavior, etc.), reproduction (hatching rate, hatching time, sex ratio, etc.) and survival (survival rate, mortality rate, population growth rate).

[0093] When research data is insufficient, the toxicity prediction data of pollutants to rare and endangered fish obtained by the toxicity prediction model can be used. Therefore, when using toxicity prediction data for research, it is necessary to screen the toxicity prediction data to ensure the reliability of the data. The toxicity prediction data screening meets the following principles:

[0094] Model input data should be quality assessed and quality controlled, and relevant to the target species, environmental conditions, etc., including the tested species, tested life stages, toxicity endpoints, water quality parameters, pollutant structure, and physical and chemical properties of the pollution;

[0095] The prediction model is built based on scientific and reasonable theories, and the prediction model has good robustness and generalization ability;

[0096] It has been verified that the error between the model prediction results and the existing experimental data is within a reasonable range;

[0097] When multiple prediction results for the same species or toxicity endpoint differ greatly, outliers should be eliminated using professional judgment or statistical methods;

[0098] For data that are abnormal in the prediction results or differ greatly from the existing experimental data, a judgment should be made based on the scope of application of the model and the actual ecosystem conditions, and some or all of the data may be discarded if necessary.

[0099] The toxicity prediction data can be screened according to the above principles to improve the reliability of the data and the accuracy of the water quality benchmark derivation.

[0100] The data are analyzed and evaluated based on the requirements for toxicity test design, test substance requirements, test organism requirements, exposure condition requirements, data priority, etc. The evaluation principles for data priority are as follows:

[0101] Research methods: toxicity experiment > model prediction;

[0102] Effect index: Acute toxicity data is usually LC 50 or EC 50 , no priority is given; the priority of chronic toxicity data is MATC>EC 20 >EC 10 =NOEC>LOEC>EC 50 >LC 50 ;

[0103] Life stage: full life cycle data > partial life cycle data > single life stage data;

[0104] Chemical analysis of the test substance solution: Measured concentration toxicity data > theoretical concentration toxicity data;

[0105] Exposure method: Flowing water exposure toxicity data > semi-static exposure toxicity data > static exposure toxicity data.

[0106] The evaluation content includes:

[0107] Testing is generally carried out using international, national or industry standard toxicity testing methods;

[0108] Toxicity data prediction models should comply with international, national or industry standard quality control requirements;

[0109] For tests using non-standard toxicity test methods, the experimental methods used should be scientifically justified;

[0110] The description of the experimental process and experimental results should be detailed;

[0111] According to the survey results of step S100, the toxicity data used to derive the water quality benchmark for rare and endangered fish should cover all species of rare and endangered fish in the waters to be studied, so as to ensure that the subsequently derived water quality benchmark can meet the requirements of all species of rare and endangered fish in the waters.

[0112] Based on the reliability analysis of the output data of the evaluation results, the data are divided into: unrestricted reliable data, restricted reliable data, unreliable data, and uncertain data. Unreliable data and uncertain data are eliminated, and unrestricted reliable data and restricted reliable data are retained.

[0113] S400, data preparation.

[0114] A410, based on the physicochemical properties of pollutants and the results of toxicity research, a model is constructed, with water quality parameters (such as temperature, hardness, pH, organic matter content, suspended particulate matter content, etc.) or their converted forms as independent variables x1, and the corresponding toxicity values ​​or their converted forms as dependent variables y1, to conduct correlation regression analysis to determine the impact of water quality parameters on the toxicity of pollutants. When water quality parameters have a significant impact on the toxicity of pollutants and the influence pattern is clear, a relevant model must be established or used to correct the toxicity data.

[0115] A420, calculate species average acute value and genus average acute value.

[0116] According to the rare and endangered fish species, EC 50 As a growth ATV, LC 50 As a survival ATV, through the formula:

[0117]

[0118] Calculate the growth SMAV and survival SMAV of each rare and endangered fish species. SMAV is the species average acute value, unit: μg / L or mg / L;

[0119] i represents the i-th rare and endangered fish species, dimensionless;

[0120] k is the type of acute toxic effect, which is generally divided into growth and survival types and is dimensionless;

[0121] m is the number of ATVs, unit: piece;

[0122] ATV is the acute toxicity value, unit: μg / L or mg / L.

[0123] For the same species, the smaller SMAV between the growth SMAV and the survival SMAV was taken into the subsequent SSD calculation. If only one SMAV was obtained, it was directly included in the subsequent calculation.

[0124] A genus may contain one or more species of rare and endangered fish, using the formula:

[0125]

[0126] The available SMAVs for each genus were geometrically averaged to obtain the growth GMAV and survival GMAV of each genus. GMAV is the genus average acute value, in μg / L or mg / L;

[0127] j is the jth rare and endangered fish species, dimensionless;

[0128] n is the number of SMAVs, in units;

[0129] For the same genus, the smaller GMAV between the growth GMAV and the survival GMAV was taken into the subsequent calculations. If only one GMAV was obtained, it was directly included in the subsequent calculations.

[0130] A430, calculate species average chronic value and genus average chronic value.

[0131] For the no observed effect concentration (NOEC) and the lowest observed effect concentration (LOEC) of a certain toxic effect of a rare and endangered fish obtained from the same exposure experiment, substitute the NOEC and LOEC into the formula:

[0132]

[0133] Calculate the maximum allowable toxic concentration (MATC) of the toxic effect of the rare and endangered fish. Where: MATC is the maximum allowable toxic concentration, unit: μg / L or mg / L or μg / g or mg / g;

[0134] NOEC is no observed effect concentration, unit: μg / L or mg / L or μg / g or mg / g;

[0135] LOEC is the lowest observed effect concentration, unit: μg / L or mg / L or μg / g or mg / g;

[0136] i is the i-th rare and endangered fish, dimensionless;

[0137] z is the zth toxic effect and is dimensionless.

[0138] According to the bioaccumulation of the target pollutant, determine whether to use toxicity data based on water concentration or tissue concentration, and divide the rare and endangered fish species into different effect categories (growth, development, reproduction, neurotoxicity, survival), and the priority determined in step S300, and divide the chronic toxicity data (MATC, EC 10 ,EC 20 、NOEC、LOEC、EC 50 and LC 50 ) as a growth, development, reproduction or neurotoxic CTV, LC 50 As the survival CTV, substitute into the formula:

[0139]

[0140] Calculate the growth SMCV, development SMCV, reproduction SMCV, nerve SMCV and survival SMCV of each rare and endangered fish. Where SMCV is the species average chronic value, unit: μg / L or mg / L or μg / g or mg / g;

[0141] i is the i-th rare and endangered fish, dimensionless;

[0142] z is the zth chronic toxic effect, which is generally divided into growth, development, reproduction, neurotoxicity and survival, and is dimensionless;

[0143] p is the number of CTVs, unit: piece;

[0144] CTV is the chronic toxicity value, unit: μg / L or mg / L.

[0145] For the same species, if multiple SMCVs were obtained based on different chronic toxic effects, the smallest SMCV was included in the subsequent SSD method calculations; if only one SMCV was obtained, it was directly included in the subsequent calculations.

[0146] A genus may contain one or more rare and endangered fishes, using the formula:

[0147]

[0148] The available SMCVs for each genus were geometrically averaged to obtain the growth GMCV, development GMCV, reproduction GMCV, neural GMCV and survival GMCV of each genus. Where: GMCV is the genus average chronic value, unit: μg / L or mg / L or μg / g or mg / g;

[0149] j is the jth rare and endangered fish species, dimensionless;

[0150] q is the number of SMCVs, unit: piece.

[0151] For the same genus, if multiple GMCVs were obtained based on different toxic effects, the smallest GMCV was included in the subsequent calculations; if only one GMCV was obtained, it was directly included in the subsequent calculations.

[0152] S500, SSD method to determine species hazard concentration.

[0153] Analyze the habitat status and bioaccumulation of pollutants of rare and endangered fish in the waters, and use the SSD method to derive the water quality benchmark for rare and endangered fish based on toxicity data that meet the needs of protecting rare and endangered fish. After fitting the distribution of species sensitivity using an appropriate model, calculate the pollutant concentration that can protect 95% of rare and endangered fish. The specific derivation process is as follows:

[0154] B510, take the common logarithm of SMAV and SMCV to obtain lgSMAV and lgSMCV. lgSMAV and lgSMCV must be all positive values, otherwise, convert the units and then take the common logarithm.

[0155] Calculate the cumulative frequency.

[0156] Sort lgSMAV and lgSMCV from small to large, and assign rank R to lgSMAV and lgSMCV according to toxicity from small to large, R = 1, 2, 3, .... If there are two or more species with the same toxicity value, arbitrarily arrange them into continuous ranks and calculate the acute and chronic cumulative frequencies F of the species respectively. R Cumulative frequency F R The calculation formula is:

[0157]

[0158] Among them, F R is the cumulative frequency;

[0159] R is the rank of the toxicity value, dimensionless;

[0160] f is the frequency, which refers to the number of rare and endangered fish corresponding to the toxicity value rank R, unit: individual;

[0161] N is the sum of all frequencies, unit: number.

[0162] Take lg SMAV and lg SMCV as independent variables x2, and the corresponding cumulative frequency F R The dependent variable y2 was used to fit the SSD model using the normal distribution model, lognormal distribution model, logistic model and loglogistic model.

[0163] B520, evaluate the model's goodness of fit according to the model goodness of fit evaluation parameters, and obtain the optimal fitting model.

[0164] Evaluation parameters include root mean square error (RMSE) and probability P value (AD test). The closer the RMSE is to 0, the higher the accuracy of the model fitting. P>0.05 indicates that the fit passes the AD test and the model conforms to the theoretical distribution.

[0165] B530, Determine the hazard concentration of rare and endangered fish.

[0166] When the value of y3 is calculated by the best fitting model as a certain cumulative frequency value, the corresponding antilogarithm of x3 The value of x3 in the figure, the antilog of x3 is the corresponding hazardous concentration (HCx3).

[0167] The calculated species hazard concentrations include the corresponding long-term and short-term species hazard concentrations HC5, HC6 and HC7 when the cumulative frequencies are 5%, 10%, 25%, 50%, 75%, 90% and 95% respectively. 10 HC 25 HC 50 HC 75 HC 90 and HC 95 HC5 is used as the benchmark value, and other hazard concentrations are used as reference for management decisions.

[0168] S600, the final toxicity value was determined by toxicity percentage ranking method.

[0169] If the probability P value of the toxicity data for all SSD models is less than 0.05, it does not meet the SSD model fitting conditions, and the toxicity percentage ranking method is used to calculate the final acute value FAV, the final chronic value FCV, and the final residual value FRV. Taking FAV as an example, the specific derivation method is as follows:

[0170] Sort lgGMAV from small to large, determine its rank R, and calculate the cumulative frequency F of each genus R Select 4 GMAVs with cumulative probabilities close to 0.05 and calculate FAV based on their cumulative frequencies. The calculation formula is as follows:

[0171]

[0172] FAV=e A

[0173] In the above formula, S 2 is the variance of ln GMAV;

[0174] S is the standard deviation of ln GMAV;

[0175] GMAV is the mean acute value;

[0176] L and A are both intermediate calculated values;

[0177] FAV is the final acute value.

[0178] It should be noted that if the average acute value of a rare and endangered fish is lower than the FAV value, the SMAV of the species should be used instead of the FAV value. It is easy to understand that the calculation method of FCV and FRV is the same as that of FAV. FCV can be based on chronic toxicity data of water concentration, and FRV can be based on chronic toxicity data of tissue concentration, and calculated according to the above method.

[0179] S700, derives water quality standards based on the calculation results of the SSD method and the toxicity percentage ranking method.

[0180] In the SSD method, the acute species hazard concentration HC5, the chronic species hazard concentration based on water body concentration-effect HC5 and the chronic species hazard concentration based on tissue concentration-toxicity data are extrapolated by assessment factors to obtain the short-term water quality benchmark, the long-term water quality benchmark and the tissue benchmark respectively; in the toxicity percentage ranking method, the short-term water quality benchmark is obtained by extrapolating the final acute value by assessment factors, the long-term water quality benchmark is obtained by extrapolating the final chronic value by assessment factors, and the tissue benchmark is obtained by extrapolating the final residual value by assessment factors.

[0181] Specifically, the formula can be used:

[0182]

[0183] Calculate the short-term water quality benchmark. SWQC (T&Efishes) is the short-term water quality benchmark for rare and endangered fishes, unit: μg / L or mg / L;

[0184] SHC5 is the 5% hazard concentration derived from the acute toxicity data of the relationship between water concentration and effect, unit: μg / L or mg / L;

[0185] SAF is a dimensionless short-term water quality benchmark assessment factor.

[0186] The formula can be:

[0187]

[0188] Calculate the long-term water quality benchmark. LWQC (T&E fishes) is the long-term water quality benchmark for rare and endangered fishes, unit: μg / L or mg / L;

[0189] LHC5 is the 5% hazard concentration derived from the chronic toxicity data based on the relationship between water concentration and effect, unit: μg / L or mg / L;

[0190] LAF is a dimensionless long-term water quality benchmark assessment factor.

[0191] The formula can be:

[0192]

[0193] Calculation is based on tissue-based benchmarks. TBC (T&E fishes) is a benchmark for rare and endangered fish based on tissues, unit: μg / g or mg / g

[0194] THC5 is the 5% hazard concentration derived from chronic toxicity data based on tissue concentration-effect, in μg / g or mg / g;

[0195] TAF is a dimensionless assessment factor based on the organization's benchmark.

[0196] The value of AF is determined based on the number of data used to derive the benchmark, the coverage of the tested organisms, and the distribution of data fitting. For the SSD method, the value is generally 2-3; when the number of genera included in the valid toxicity data is greater than 15, the AF value is 2; when the number of genera included in the valid toxicity data is less than or equal to 15, the value is generally 3.

[0197] For the toxicity percentage ranking method, if all the data used to derive FAV are measured acute toxicity data, the SAF value is 2, and if predicted acute toxicity data are included, the SAF value is 4; if all the data used to derive FCV are measured chronic toxicity data, the LAF value is 1, and if predicted chronic toxicity data are included, the LAF value is 2; if all the data used to derive FRV are measured chronic toxicity data, the TAF value is 1, and if predicted chronic toxicity data are included, the TAF value is 2.

[0198] For non-bioaccumulative pollutants, the derived water quality benchmarks include short-term water quality benchmarks and long-term water quality benchmarks; for bioaccumulative pollutants, the derived water quality benchmarks include water quality benchmarks, long-term water quality benchmarks and organization-based benchmarks; for bioaccumulative pollutants, the derived water quality benchmarks include organization-based benchmarks.

[0199] The short-term water quality benchmark, long-term water quality benchmark and tissue-based benchmark are respectively smaller than the minimum SMAV and SMCV of all rare and endangered fish species; otherwise, the minimum SMAV or SMCV of the most sensitive rare and endangered fish species should be used as the short-term water quality benchmark, long-term water quality benchmark and tissue-based benchmark.

[0200] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for deriving water quality benchmarks for rare and endangered fish, characterized by: The steps include: Conduct habitat surveys, biological surveys, and pollutant surveys, and divide water areas and pollutants; Obtain pollutant exposure data, pollutant toxicity data, test organism information and relevant water quality parameter data; Screen the toxicity data of pollutants to different test organisms according to pre-established principles and priority evaluation principles; The SSD method was used to calculate species hazard concentrations; Short-term water quality standards, long-term water quality standards and tissue residue standards are derived based on the calculation results of the SSD method.

2. The method for deriving water quality standards for rare and endangered fish according to claim 1, characterized in that: The SSD method is preferred to calculate the species hazard concentration, and the HC5 corresponding to the cumulative frequency of 5% is used to derive the water quality benchmark; When the SSD method is used to calculate species hazard concentrations, the probability P value of the SSD method is calculated. If the probability P values ​​of all SSD models are less than 0.05, the toxicity percentage ranking method is used to determine the final toxicity value, and then the short-term water quality benchmark, long-term water quality benchmark and tissue residue benchmark are derived.

3. The method for deriving water quality standards for rare and endangered fish according to claim 2, characterized in that: Before calculating the final toxicity value by the toxicity percentage ranking method, the average acute value and the average chronic value are calculated. The calculation formula for the average acute value is: In the above formula, GMAV is the mean acute value; SMAV is the species mean acute value; j is the jth rare and endangered fish species, dimensionless; k is the type of acute toxic effect; n is the number of SMAVs, in units; For the same genus, the smaller GMAV between the growth GMAV and the survival GMAV was taken into the subsequent calculation of the toxicity percentage ranking method. If only one GMAV was obtained, it was directly included in the subsequent calculation; The calculation formula of the average chronic value is: In the above formula, GMCV is the average chronic value; SMCV is the species mean chronic value; z is the zth chronic toxic effect; q is the number of SMCVs; For the same genus, if multiple GMCVs were obtained based on different chronic toxic effects, the smallest GMCV was included in the subsequent calculations; if only one GMCV was obtained, it was directly included in the subsequent calculations.

4. The method for deriving water quality standards for rare and endangered fish according to claim 2, characterized in that: When the final toxicity value is determined by the toxicity percentage ranking method, the final acute value FAV, the final chronic value FCV, and the final residual value FRV are calculated. The final acute value is extrapolated by the assessment factor to obtain the short-term water quality benchmark, the final chronic value is extrapolated by the assessment factor to obtain the long-term water quality benchmark, and the final residual value is extrapolated by the assessment factor to obtain the tissue benchmark.

5. The method for deriving water quality standards for rare and endangered fish according to claim 4, characterized in that: The calculation method of the final toxicity value and the final acute value FAV is as follows: Sort lg GMAV from small to large, determine its rank R, and calculate the cumulative frequency F of each genus R ; Select multiple GMAVs with cumulative probabilities close to 0.05 and calculate FAV based on the cumulative frequency; the calculation formula is as follows: FAV=e A In the above formula, S 2 is the variance of ln GMAV; S is the standard deviation of ln GMAV; GMAV is the mean acute value; L and A are both intermediate calculated values; If the species mean acute value SMAV of rare and endangered fish is lower than the FAV value, the species SMAV shall be used instead of the FAV value; The final chronic value FCV and the final residual value FRV respectively use the chronic toxicity data based on water concentration-effect and the chronic toxicity data based on tissue concentration-effect, and the calculation method is the same as the calculation method of the final acute value FAV.

6. The method for deriving water quality standards for rare and endangered fish according to claim 1, characterized in that: The water bodies and pollutants are divided into: Through habitat surveys and biological surveys, the proposed research waters are divided into common habitat waters and special breeding waters; According to the pollutant survey, if BAF≤2000, it is a non-bioaccumulative pollutant; 2000<BAF≤5000, it is a bioaccumulative pollutant; BAF>5000, which is a highly bioaccumulative pollutant.

7. The method for deriving water quality standards for rare and endangered fish according to claim 1, characterized in that: When screening pollutant toxicity data, the pollutant toxicity data are divided into acute toxicity data and chronic toxicity data. Acute toxicity data are toxicity data based on water concentration-effect, including toxic effects on growth and survival. Chronic toxicity data are toxicity data based on water concentration-effect and toxicity data based on tissue concentration-effect, including toxic effects on growth, development, nerves, reproduction and survival.

8. The method for deriving water quality standards for rare and endangered fish according to claim 1, characterized in that: The pollutant toxicity data obtained cover all rare and endangered fish in the proposed study waters, and the sources of pollutant toxicity data include toxicity tests and model predictions.

9. The method for deriving water quality standards for rare and endangered fish according to claim 8, characterized in that: The pre-established principles are: The model input data should be quality assessed and quality controlled, and should be relevant to the target species and environmental conditions. The input data should include the tested species, tested life stages, toxicity endpoints, water quality parameters, pollutant structure, and physical and chemical properties of the pollutants. The error between the model prediction results and the existing experimental data is within the allowable range; When multiple prediction results for the same species or toxicity endpoint differ too much, outliers are removed; For data that are abnormal in the prediction results or differ greatly from the existing experimental data, a judgment is made based on the scope of application of the model and the actual ecosystem conditions, and some or all of the data are discarded.

10. The method for deriving water quality standards for rare and endangered fish according to claim 1, characterized in that: Before calculating the species hazard concentration using the SSD method, the species average acute value and species average chronic value are calculated. The calculation formula for the species average acute value is: In the above formula, SMAV is the species mean acute value; i represents the i-th rare and endangered fish species; k is the type of acute toxic effect; m is the number of ATVs; ATV is the acute toxicity value; For the same species, the smaller SMAV between the growth SMAV and the survival SMAV was taken into the subsequent SSD calculation. If only one SMAV was obtained, it was directly included in the subsequent calculation. The calculation formula for the average chronic value is: In the above formula, SMCV is the species mean chronic value; i is the i-th rare and endangered fish; z is the zth chronic toxic effect; p is the number of CTVs; CTV is the chronic toxicity value; For the same species, if multiple SMCVs were obtained based on different chronic toxic effects, the smallest SMCV was included in the subsequent SSD method calculations; if only one SMCV was obtained, it was directly included in the subsequent calculations.

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