A method for deriving water quality criteria for a rare and endangered fish species

Abstract

The present application relates to the technical field of water quality criteria prediction, and particularly relates to a rare and endangered fish water quality criteria derivation method, which comprises the following steps: conducting habitat investigation, biological investigation and pollutant investigation, and dividing water areas and pollutants; obtaining pollutant exposure data, pollutant toxicity data, test biological information and related water quality parameter data; screening the toxicity data of pollutants to different test organisms according to the principles and priority evaluation principles; using the SSD method to calculate the species hazard concentration, otherwise using the toxicity percentage ranking method to determine the final toxicity value; deriving short-term water quality criteria, long-term water quality criteria and tissue residue criteria according to the calculation results of the SSD method and the toxicity percentage ranking method. The present application can derive water quality criteria for rare and endangered fish, and provide technical support for the research of rare and endangered fish.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water quality criteria prediction, and particularly relates to a rare and endangered fish water quality criteria derivation method. BACKGROUND

[0002] Water quality criteria refers to the maximum concentration or level of pollutants or harmful factors in the water environment that does not produce harmful effects on human health or water ecological system. Rare and endangered fish water quality criteria refers to the maximum concentration or level of pollutants or harmful factors in the water environment that does not produce harmful effects on rare and endangered fish and its ecological function, including short-term water quality criteria, long-term water quality criteria and tissue criteria.

[0003] The short-term water quality criteria refers to the maximum concentration or level of pollutants or harmful factors in the water body that does not produce acute harmful effects on rare and endangered fish and its ecological function; the long-term water quality criteria refers to the maximum concentration or level of pollutants or harmful factors in the water body that does not produce chronic harmful effects on rare and endangered fish and its ecological function; and the tissue criteria refers to the maximum concentration or level of pollutants or harmful factors in the biological body that does not produce chronic harmful effects on rare and endangered fish and its ecological function.

[0004] A derivation method of fresh water aquatic animal acute water quality criteria is disclosed in Chinese patent with publication number CN107991452A, which comprises the following steps: a, collection and screening of acute toxicity data; step b, sequentially obtaining the genus average acute value and the corresponding cumulative probability of the screened acute toxicity data; step c, constructing a cubic spline function S(x) with the natural logarithm of the genus average acute value obtained in step b as the abscissa X and the corresponding cumulative probability P as the ordinate Y, assigning values to Y, and correspondingly obtaining an X value, taking the inverse logarithm of X to obtain the short-term hazard concentration STHC100Y, which is the acute water quality criteria value for the target pollutant. The derivation method of fresh water aquatic animal acute water quality criteria provides better technical support for various studies of fish.

[0005] However, the current water quality criteria limits are all safety thresholds for ordinary organisms or fish, and there is no standard for rare and endangered fish, for example, the standard limit values of copper in class I and class II water bodies are 0.01 mg / L and 1 mg / L respectively, which is equivalent to or higher than the concentration value causing chronic toxicity of Chinese sturgeon, and cannot effectively protect Chinese sturgeon. SUMMARY

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

[0007] The present application provides a rare and endangered fish water quality criteria derivation method, which adopts the following technical scheme:

[0008] A method for deriving water quality criteria for rare and endangered fish species, comprising the following steps:

[0009] Conducting habitat investigation, biological investigation and pollutant investigation, and classifying water bodies and pollutants;

[0010] Obtaining pollutant exposure data, pollutant toxicity data, information of test organisms and related water quality parameter data;

[0011] According to the pre-established principles and priority evaluation principles, the toxicity data of pollutants on different test organisms are screened;

[0012] The SSD method is used to calculate the species hazard concentration;

[0013] The short-term water quality criteria, long-term water quality criteria and tissue residue criteria are derived according to the calculation results of the SSD method.

[0014] In a specific implementable scheme, the SSD method is used to calculate the species hazard concentration, and the HC5 corresponding to the cumulative frequency of 5% is used to derive the water quality criteria;

[0015] When the SSD method is used to calculate the species hazard concentration, the probability P value of the SSD method is calculated, if the probability P value of all SSD models is less than 0.05, the final toxicity value is determined by using the toxicity percentage ranking method, and then the short-term water quality criteria, long-term water quality criteria and tissue residue criteria are derived.

[0016] In a specific implementable scheme, before the toxicity percentage ranking method is used to calculate the final toxicity value, the genus average acute value and the genus average chronic value are calculated, wherein the calculation formula of the genus average acute value is:

[0017]

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

[0019] SMCV is the species average acute value;

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

[0021] k is the acute toxicity effect species;

[0022] n is the number of SMAV, unit: pieces;

[0023] For the same genus, the smaller GMAV between the growth type GMAV and the survival type GMAV is taken into the subsequent calculation of the toxicity percentage ranking method, if only one GMAV is obtained, it is directly taken into the subsequent calculation;

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

[0025]

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

[0027] SMCV is the species average chronic value;

[0028] z is the zth chronic toxicity effect;

[0029] q is the number of SMCV;

[0030] For the same genus, if multiple GMCV are obtained according to different chronic toxicity effects, the smallest GMCV is taken into subsequent calculation, and if only one GMCV is obtained, it is directly taken into subsequent calculation.

[0031] In one specific implementation, when the toxicity percentage ranking method is used to determine the final toxicity value, the final acute value FAV, the final chronic value FCV, and the final residual value FRV are calculated, the short-term water quality criteria is obtained after the final acute value is extrapolated by the assessment factor, the long-term water quality criteria is obtained after the final chronic value is extrapolated by the assessment factor, and the tissue criteria is obtained after the final residual value is extrapolated by the assessment factor.

[0032] In one specific implementation, the calculation method of the final toxicity value, and the calculation method of the final acute value FAV are as follows:

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

[0034] Multiple GMAV with cumulative probability close to 0.05 are selected, and FAV is calculated in combination with 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 genus average acute value;

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

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

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

[0043] In a specific embodiment, the water area and the pollutant are divided as follows:

[0044] Through habitat investigation and biological investigation, the water area to be studied is divided into common habitat water area and special breeding water area.

[0045] According to the pollutant investigation, if BAF≤2000, it belongs to non-bioaccumulative pollutant.

[0046] 2000<BAF≤5000, it belongs to bioaccumulative pollutant.

[0047] BAF>5000, it belongs to high bioaccumulative pollutant.

[0048] In a specific embodiment, when the pollutant toxicity data is screened, the pollutant toxicity data is divided into acute toxicity data and chronic toxicity data. The acute toxicity data is water body concentration-effect based toxicity data, including growth and survival toxicity effects. The chronic toxicity data is water body concentration-effect based toxicity data and tissue concentration-effect based toxicity data, including growth, development, nervous, reproduction and survival toxicity effects.

[0049] In a specific embodiment, the prepared principles are as follows:

[0050] The model input data should be quality evaluated and quality controlled, and related to target species and environmental conditions. The input data includes test species, test life stage, toxicity endpoint, water quality parameter, pollutant structure and pollutant physical and chemical properties.

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

[0052] When the difference between multiple prediction results of the same species or toxicity endpoint is too large, the outlier is removed.

[0053] For the data in the prediction result that appears abnormal or differs too much from the existing experimental data, the applicable range of the model and the actual ecological system conditions are combined to judge, and part or all of the data is discarded.

[0054] In a specific embodiment, before the SSD method calculates the species hazard concentration, the species average acute value and the species average chronic value are calculated, and the calculation formula of the species average acute value is as follows:

[0055]

[0056] In the formula, SMAV is an average acute value;

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

[0058] l is the number of acute toxicity effects;

[0059] m is the number of ATVs;

[0060] ATV is an acute toxicity value;

[0061] For the same species, the smaller SMAV of the growth type SMAV and the survival type SMAV is taken into the calculation of the subsequent SSD method, and if only one SMAV is obtained, it is directly taken into the subsequent calculation;

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

[0063]

[0064] In the formula, SMCV is the average chronic value of the species;

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

[0066] z is the z-th chronic toxicity effect;

[0067] p is the number of CTVs;

[0068] CTV is a chronic toxicity value;

[0069] For the same species, if multiple SMCVs are obtained according to different chronic toxicity effects, the smallest SMCV is taken into the calculation of the subsequent SSD method, and if only one SMCV is obtained, it is directly taken into the subsequent calculation.

[0070] In summary, the present application has the following advantages:

[0071] The water quality benchmark derivation method for rare and endangered fish species is constructed, the water quality of the water area where the rare and endangered fish species inhabit and breed is more accurately controlled, and the rare and endangered fish species is better protected. By combining the SSD algorithm and the toxicity percentage sorting method, a more accurate water quality benchmark is derived and established. BRIEF DESCRIPTION OF DRAWINGS

[0072] Figure 1 is a flowchart of the water quality benchmark derivation method for rare and endangered fish species.

[0073] Figure 2 is a flowchart of the data acquisition of the water quality benchmark derivation method for rare and endangered fish species.

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

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

[0076] The following description will be made in conjunction with the accompanying drawings. Figures 1-4 The present application is further described in detail.

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

[0078] S100, environmental investigation.

[0079] The investigation content includes habitat investigation, biological investigation and pollutant investigation. Since there are different requirements for water areas where rare and endangered fish species inhabit and breed, through habitat investigation and biological investigation, the water area to be studied is divided into ordinary habitat water area and special breeding water area, which is convenient for subsequent development of different water quality criteria.

[0080] Through pollutant investigation, the pollutants are divided into non-bioaccumulative pollutants, bioaccumulative pollutants and high bioaccumulative pollutants. Further, if the biological accumulation factor (BAF) is ≤2000, it belongs to non-bioaccumulative pollutants; if 2000<BAF≤5000, it belongs to bioaccumulative pollutants; and if BAF>5000, it belongs to high bioaccumulative pollutants.

[0081] The habitat investigation is mainly aimed at the habitat environment of rare and endangered fish species, including habitat characteristics, hydrological characteristics, physical characteristics, chemical characteristics, etc.

[0082] The biological investigation is mainly aimed at rare and endangered fish species, including basic information, biological groups, biological characteristics, food (bait organisms) composition, ecological distribution, ecological function, etc.

[0083] The pollutant investigation is mainly aimed at target pollutants, including basic information, physicochemical properties, biological enrichment potential, etc.

[0084] S200, data acquisition.

[0085] Pollutant exposure data, pollutant toxicity data, test organism information and related water quality parameter data are acquired. The pollutant exposure data includes sampling information, sample analysis information, exposure data type and data source, etc. The sampling information includes: the basin to which it belongs, the station name, the station longitude and latitude, the sampling time, the sampling medium, etc. The sample analysis information includes concentration value, analysis method, etc. The exposure data type includes water concentration, sediment concentration, biological concentration, etc.

[0086] The pollutant toxicity data includes test conditions, test results, and data sources. The test conditions include test type, test location, test method, purity of test substance, exposure method (flowing water, semi-static, static), test load, exposure concentration (measured, theoretical), test matrix (freshwater, seawater, etc.), test design (control group, parallel group, number of test groups, etc.), solvent information (names and concentrations of cosolvents, emulsifiers, dispersants, etc.), test water quality parameters (temperature, pH, hardness, dissolved oxygen, organic matter content, suspended solids content, etc.), light intensity, light-dark ratio, etc. The test results include exposure time, toxicity endpoint, effect indicator, and effect concentration, etc.

[0087] The test organism information includes the Chinese and Latin names of the fish receiving the test, taxonomic status, biological source, age, body length, body weight, gender, exposure life stage, habitat characteristics, geographic distribution area, and living habits, etc. The relevant water quality parameter data are the relevant water quality parameters of surface water in China, such as temperature, pH, hardness, organic matter content, suspended solids 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 the research data are insufficient, the toxicity data of the target pollutant on rare and endangered fish can be obtained by supplementing the toxicity test of alternative organisms and model prediction (such as QSAR-ICE model).

[0089] The data sources can be domestic and foreign biological toxicity databases with clear sources, literatures or reports published through peer review, relevant data published by officials, other source data judged to be reliable by experts, and pollutant toxicity data supplemented by test and prediction in the process of benchmark derivation.

[0090] S300, data screening.

[0091] The toxicity data is classified into acute toxicity data and chronic toxicity data. The acute toxicity data is water body concentration-effect-based toxicity data, including two types of toxicity effects, i.e. growth (body weight, body length, growth rate, etc.) and survival (survival rate, mortality rate).

[0092] The chronic toxicity data is divided into two parts, i.e. water body concentration-effect-based toxicity data and tissue concentration-effect-based toxicity data, and the toxicity effects include five types, i.e. growth (body weight, body length, growth rate, etc.), development (malformation rate, teratogenic index, etc.), nervous system (feeding behavior, avoidance behavior, etc.), reproduction (hatching rate, hatching time, sex ratio, etc.), and survival (survival rate, mortality rate, population growth rate).

[0093] Since the toxicity prediction model can be used to obtain the toxicity prediction data of pollutants to rare and endangered fish species when the research data is insufficient, the toxicity prediction data needs to be screened to ensure the reliability of the data when using the toxicity prediction data for research. The toxicity prediction data screening meets the following principles:

[0094] The model input data should be quality evaluated and quality controlled, and related to the target species, environmental conditions, etc., including the test species, test life stage, toxicity endpoint, water quality parameters, pollutant structure, and pollutant physical and chemical properties, etc.;

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

[0096] After verification, the error between the model prediction results and the existing experimental data is within a reasonable range;

[0097] When the multiple prediction results of the same species or toxicity endpoint differ greatly, the outliers should be removed by combining professional judgment or statistical methods;

[0098] For data that appears abnormal in the prediction results or differs greatly from the existing experimental data, the model's applicable scope and actual ecological system conditions should be considered for judgment, and if necessary, some or all of the data can be discarded.

[0099] Through the above principles for screening toxicity prediction data, the reliability of the data is improved, and the accuracy of water quality criteria derivation is improved.

[0100] Based on the requirements of toxicity test design, test substance, test organism, exposure conditions, and data priority, the data is analyzed and evaluated. The evaluation principles of data priority are as follows:

[0101] Research means: toxicity test > model prediction;

[0102] Effect index: acute toxicity data is usually LC 50 or EC 50 , without priority; the priority of chronic toxicity data is MATC > EC 20 > EC 10 = NOEC > LOEC > EC 50 > LC 50 ;

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

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

[0105] Exposure mode: running water exposure toxicity data > semi-static exposure toxicity data > static exposure toxicity data.

[0106] The evaluation content includes:

[0107] Generally, international, national or industry standard toxicity test methods are used for testing;

[0108] The toxicity data prediction model should meet the quality control requirements of international, national or industry standards;

[0109] For tests using non-standard toxicity test methods, the experimental methods used should be scientific and reasonable;

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

[0111] According to the research results of step S100, the toxicity data used for the derivation of water quality criteria for rare and endangered fish should cover all species of rare and endangered fish in the water area to be studied. In this way, the water quality criteria derived later can meet the requirements of all species of rare and endangered fish in the water area.

[0112] Based on the evaluation results, the data reliability analysis outputs data, which is divided into: unrestricted reliable data, limited reliable data, unreliable data, and uncertain data. Unreliable data and uncertain data are excluded, and unrestricted reliable data and limited reliable data are retained.

[0113] S400, data preparation.

[0114] A410, according to the physicochemical properties of pollutants and the results of toxicity research, a model is constructed, taking 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 corresponding toxicity values or their converted forms as dependent variables y1, correlation regression analysis is carried out to determine the influence of water quality parameters on pollutant toxicity. When the influence of water quality parameters on pollutant toxicity is significant and the influence law is clear, the relevant model should 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 species of rare and endangered fish, EC 50 As a growth class ATV, LC 50 As a survival class ATV, through the formula:

[0117]

[0118] Calculate the growth class SMAV and survival class SMAV of each rare and endangered fish. Among them, 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 acute toxicity effect type, generally divided into growth and survival, dimensionless;

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

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

[0123] For the same species, the smaller of the growth and survival SMAVs is taken into the subsequent SSD method calculation. If only one SMAV is obtained, it is directly taken into the subsequent calculation.

[0124] One genus may contain one or more species of rare and endangered fish. The formula is:

[0125]

[0126] The available SMAVs of each genus are geometrically averaged to obtain the growth and survival GMAVs of each genus. Among them, GMAV is the genus average acute value, unit: μg / L or mg / L;

[0127] j is the j-th genus of rare and endangered fish, dimensionless;

[0128] n is the number of SMAVs, unit: pieces;

[0129] For the same genus, the smaller of the growth and survival GMAVs is taken into the subsequent calculation. If only one GMAV is obtained, it is directly taken into the subsequent calculation.

[0130] A430, calculate the 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 toxicity effect of a certain rare and endangered fish obtained from the same exposure experiment, the NOEC and LOEC are substituted into the formula:

[0132]

[0133] The maximum allowable toxicant concentration MATC of the toxicity effect of the rare and endangered fish is calculated. In the formula: MATC is the maximum allowable toxicant concentration, unit: μg / L or mg / L or μg / g or mg / g;

[0134] NOEC is the 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 z-th toxic effect, 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 by different effect categories (growth, development, reproduction, neurotoxicity, survival), and the priority determined in step S300, and the chronic toxicity data (MATC, EC 10 , EC 20 , NOEC, LOEC, EC 50 and LC 50 ) as growth, development, reproduction or neurotoxicity category CTV, LC 50 as survival category CTV, respectively into the formula:

[0139]

[0140] Calculate the growth category SMCV, development category SMCV, reproduction category SMCV, neurotoxicity category SMCV and survival category SMCV of each rare and endangered fish. In the formula, 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 z-th chronic toxicity effect, generally divided into growth, development, reproduction, neurotoxicity and survival categories, dimensionless;

[0143] p is the number of CTV, unit: pieces;

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

[0145] For the same species, if multiple SMCVs are obtained according to different chronic toxicity effects, take the smallest SMCV into the subsequent SSD method calculation, if only one SMCV is obtained, directly into the subsequent calculation.

[0146] One genus may contain one or more rare and endangered fish, and the formula is:

[0147]

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

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

[0150] q is the number of SMCV, unit: pieces.

[0151] For the same genus, if multiple GMCVs are obtained according to different toxic effects, the smallest GMCV is taken into subsequent calculation, and if only one GMCV is obtained, it is directly taken into subsequent calculation.

[0152] S500, SSD method determines the species hazard concentration.

[0153] Based on the toxicity data meeting the protection needs of rare and endangered fish, the SSD method is used to derive the water quality criteria for rare and endangered fish. After fitting the distribution of species sensitivity using appropriate models, the pollutant concentration that can protect 95% of rare and endangered fish is calculated. The specific derivation process is as follows:

[0154] B510, the SMAV and SMCV included in the calculation are taken as common logarithm to obtain lgSMAV and lgSMCV. lgSMAV and lgSMCV must all be positive, otherwise after unit conversion, take the common logarithm again.

[0155] Calculate the cumulative frequency.

[0156] lgSMAV and lgSMCV are sorted from small to large, and the rank R of lgSMAV and lgSMCV is assigned according to the toxicity from small to large, R = 1, 2, 3, … If the toxicity values of two or more species are the same, they are arbitrarily arranged in consecutive ranks, and the acute and chronic cumulative frequencies F R of the species are calculated. The calculation formula of cumulative frequency F R is:

[0157]

[0158] Where, F R is the cumulative frequency;

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

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

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

[0162] Take lg SMAV and lg SMCV as independent variables x2, respectively, and take the corresponding cumulative frequency F R as dependent variable y2, use normal distribution model, lognormal distribution model, logistic model and log logistic model to fit SSD model.

[0163] B520, evaluate the fitting degree of the model according to the model fitting degree evaluation parameter, and obtain the optimal fitting model.

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

[0165] B530, determine the concentration of rare and endangered fish hazards.

[0166] Through the optimal fitting model, the value of y3 when the cumulative frequency value is a certain value is calculated, and the inverse logarithm of x3 value corresponding to x3, the inverse logarithm of x3 is the corresponding species hazard concentration (HCx3).

[0167] The calculated species hazard concentration includes the corresponding long-term and short-term species hazard concentrations HC5, HC 10 , HC 25 , HC 50 , HC 75 , HC 90 and HC 95 when the cumulative frequency is 5%, 10%, 25%, 50%, 75%, 90% and 95%, respectively. HC5 is used as a reference value, and other species hazard concentrations are used for management decision reference.

[0168] S600, toxicity percentage ranking method to determine the final toxicity value.

[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 condition, then 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. Take FAV as an example, the specific derivation method is as follows:

[0170] Sort lgGMAV from small to large to determine its rank R, and calculate the cumulative frequency F R of each genus. Select four GMAV with cumulative probability close to 0.05, and calculate FAV combining 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 genus average acute value;

[0176] L and A are both intermediate calculation 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 species is lower than the FAV value, the SMAV value of the species should be used instead of the FAV value. It is easy to understand that the calculation methods of FCV and FRV are the same as FAV, FCV can be based on chronic toxicity data of water body concentration, FRV can be based on chronic toxicity data of tissue concentration, and calculated according to the above method.

[0179] S700, according to the calculation results of SSD method and toxicity percentage ranking method, derive water quality criteria.

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

[0181] Specifically, the short-term water quality criteria can be calculated by the formula:

[0182]

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

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

[0185] SAF is the assessment factor of short-term water quality criteria, dimensionless.

[0186] The long-term water quality criteria can be calculated by the formula:

[0187]

[0188] LWQC(T&E fishes) is the long-term water quality criterion for T&E fishes, unit: μg / L or mg / L;

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

[0190] LAF is the assessment factor for long-term water quality criterion, dimensionless.

[0191] The tissue-based criterion can be calculated by the formula:

[0192]

[0193] The tissue-based criterion can be calculated by the formula:

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

[0195] TAF is the assessment factor for tissue-based criterion, dimensionless.

[0196] The value of AF is determined comprehensively according to the number of data used for deriving the criterion, the coverage of test organisms and the distribution of data fitting, etc. For the SSD method, the value is generally 2-3; when the number of genera included in the effective toxicity data is greater than 15, the value of AF is 2; when the number of genera included in the effective 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 for deriving FAV are measured acute toxicity data, the value of SAF is 2, if predicted acute toxicity data are included, the value of SAF is 4; if all the data used for deriving FCV are measured chronic toxicity data, the value of LAF is 1, if predicted chronic toxicity data are included, the value of LAF is 2; if all the data used for deriving FRV are measured chronic toxicity data, the value of TAF is 1, if predicted chronic toxicity data are included, the value of TAF is 2.

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

[0199] The short-term water quality criteria, long-term water quality criteria and tissue-based criteria are less than the minimum SMAV and SMCV of all rare and endangered fish, otherwise, the minimum SMAV or SMCV of the most sensitive rare and endangered fish should be taken as the short-term water quality criteria, long-term water quality criteria and tissue-based criteria.

[0200] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, and thus: any equivalent changes made in the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for deriving water quality criteria for rare and endangered fish species, characterized by: The method comprises the following steps: carrying out habitat investigation, biological investigation and pollutant investigation, and classifying water areas and pollutants; obtaining pollutant exposure data, pollutant toxicity data, information of test organisms and related water quality parameter data; screening the toxicity data of pollutants to different test organisms according to the pre-established principles and priority evaluation principles; preferably using the SSD method to calculate species hazard concentration, and using the species hazard concentration HC5 corresponding to the cumulative frequency of 5% to derive water quality criteria, including short-term water quality criteria, long-term water quality criteria and tissue residue criteria; when the SSD method is used to calculate the species hazard concentration, the probability P value of the SSD method is calculated, if the probability P value of all SSD models is less than 0.05, the final toxicity value is determined by using the toxicity percentage ranking method, and then the short-term water quality criteria, the long-term water quality criteria and the tissue residue criteria are derived; When the final toxicity value is determined using the toxicity percentage ranking method, the final acute value , the final chronic value , and the final residual value are calculated. The final acute value, after extrapolation by the assessment factor, gives the short-term water quality criterion, the final chronic value, after extrapolation by the assessment factor, gives the long-term water quality criterion, and the final residual value, after extrapolation by the assessment factor, gives the tissue criterion. The method of calculation of the final toxicity value, the final acute value is: Will Sort from small to large, determine its rank , respectively, the cumulative frequency of each class ; selecting a plurality of cumulative probabilities close to 0.05 , in combination with the cumulative frequency calculation ; the calculation formula is as follows: In the above formula, is the variance of For the standard deviation; To be average acute value; and are intermediate calculation values; if the average acute value of the species of rare and endangered fish is less than the value, the species is replaced with the value; Final chronic value and final residual value Using the water body concentration-effect based chronic toxicity data and the tissue concentration-effect based chronic toxicity data, respectively, the calculation method is the same as that of the final acute value .

2. The method for deriving water quality criteria for rare and endangered fish species according to claim 1, characterized in that: Before the toxicity percentage ranking method is used to calculate the final toxicity value, the genus average acute value and the genus average chronic value are calculated, wherein the calculation formula of the genus average acute value is: In the above formulae, is the mean acute value; is an average acute value; For the first The genus is rare and endangered, dimensionless; For acute toxicity effects category; For Number, units of individual; For the same genus, take the growth class and the survival class with the lower numerical value Incorporate into the subsequent calculation of the percentage ranking of toxicity if only 1 is obtained; directly into subsequent calculations. the calculation formula of the genus average chronic value is: In the above formulae, is the mean chronic value; an average chronic value; For the Chronic toxic effects; For Number; For the same genus, if multiple then take the minimum and incorporate into subsequent calculations if only 1 then incorporate directly into subsequent calculations.

3. The method for deriving water quality criteria for rare and endangered fish species according to claim 1, wherein: The classification of water areas and pollutants is specifically as follows: through habitat investigation and biological investigation, the water area to be studied is classified into ordinary habitat water area and special breeding water area; according to the pollutant investigation, if the biological accumulation factor BAF is less than or equal to 2000, the pollutant is a non-biological accumulation pollutant; 2000 < BAF ≤ 5000, the pollutant is a biological accumulation pollutant; BAF > 5000, the pollutant is a high biological accumulation pollutant.

4. The method for deriving water quality criteria for rare and endangered fish species according to claim 1, wherein: When the pollutant toxicity data is screened, the pollutant toxicity data is classified into acute toxicity data and chronic toxicity data, the acute toxicity data is water body concentration-effect-based toxicity data, including toxicity effects of growth and survival, and the chronic toxicity data is water body concentration-effect-based toxicity data and tissue concentration-effect-based toxicity data, including toxicity effects of growth, development, nervous system, reproduction and survival.

5. The method for deriving water quality criteria for rare and endangered fish species as claimed in claim 1, wherein: The obtained pollutant toxicity data covers all rare and endangered fish in the water area to be studied, and the sources of the pollutant toxicity data include toxicity tests and model predictions.

6. The method of deriving water quality criteria for rare and endangered fish species as claimed in claim 5, wherein: The pre-established principles are as follows: the input data of the model should be subjected to quality evaluation and quality control, and be related to target species and environmental conditions, and the input data includes test species, test life stage, toxicity endpoint, water quality parameter, pollutant structure and physical and chemical properties of the pollutant; the error between the model prediction result and the existing experimental data is within the allowable range; when the difference between multiple prediction results of the same species or toxicity endpoint is too large, the outlier is removed; for the data in the prediction result which is abnormal or differs too much from the existing experimental data, the data is judged in combination with the applicable range of the model and the actual ecological system conditions, and part or all of the data is discarded.

7. The method for deriving water quality criteria for rare and endangered fish species as claimed in claim 1, wherein: Before the SSD method is used to calculate the species hazard concentration, the species average acute value and the species average chronic value are calculated, wherein the calculation formula of the species average acute value is: In the above formula, is an average acute value; representing the first species of rare and endangered fish; For acute toxicity effects category; To Number; For acute toxicity values; For the same species, take growth class and survival class with smaller values into the calculation of the subsequent SSD method, if only 1 is obtained, directly into the subsequent calculation; the calculation formula of the species average chronic value is: In the above formula, is an average chronic value; is the 45th rare and endangered fish species; For the Chronic toxic effects; To Quantity; Chronic toxicity values; For the same species, if multiple then take the minimum and incorporate into the subsequent SSD calculation if only 1 then incorporate directly into the subsequent calculation.

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