A rapid estimation method for algal biodiversity index in Class II water bodies

Abstract

The present invention discloses a method for rapid estimation of algae biodiversity index of Class II water bodies. The method uses chlorophyll concentration and cyanobacterial cell number collected in situ by a Hash DS 5X water quality monitor, and constructs a rapid estimation method of Pielou evenness index and Shannon‑Wiener diversity index applicable to Baima Lake and Hongze Lake, so as to achieve on-site rapid estimation of algae biodiversity and provide a basis for evaluating the health of water bodies.

Description

Technical Field

[0001] The invention relates to the field of water body ecological health assessment, and more specifically, to a method for quickly estimating algae biodiversity index of Class II water bodies. Background Art

[0002] Inland lakes, rivers, and reservoirs are Class II water bodies, and oceans are Class I water bodies. The water quality of Class II water bodies directly affects the lives and production of surrounding residents. Algal biodiversity is one of the methods to evaluate the health of water bodies. There are many algal biodiversity indicators. The Pielou evenness index and the Shannon-Wiener diversity index are commonly used indicators. The larger the value of the Pielou evenness index, the better the water quality. 0~0.2 indicates that the water body is eutrophic, 0.2~0.3 indicates mesotrophic, 0.3~0.5 indicates mesotrophic, and greater than 0.5 indicates oligotrophic, and the water quality is very good; the Shannon-Wiener diversity index is also the larger the value, the better the water quality. 0~1 indicates that the water body is eutrophic, 1~2 indicates mesotrophic, 2~3 indicates mesotrophic, and greater than 3 indicates oligotrophic, and the water quality is very good. Baima Lake and Hongze Lake are important water sources for Huai'an City, of which Baima Lake is the second water source for Huai'an City. The biodiversity of different lakes varies greatly. Understanding the algae biodiversity of lakes and rivers entering and leaving the lakes is of great significance for evaluating the health of water bodies and the management and protection of water environments. The evaluation of algae diversity requires the collection of water samples, the microscopic counting of algae of different species, and then the calculation of the diversity index. After the water samples are collected, they need to be fixed, algae enriched, and counted under a microscopic microscope. The whole process is time-consuming and it is impossible to make a preliminary evaluation of the health of the water body on site. At present, there is an urgent need for a method to preliminarily estimate the biodiversity through in-situ detection of water quality parameters. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for rapidly estimating the algae biodiversity index of Class II water bodies to solve the above-mentioned problems, so as to realize on-site rapid estimation of the algae biodiversity of Baima Lake, Hongze Lake and surrounding rivers, and provide a basis for evaluating the health of water bodies.

[0004] Eutrophic water bodies have poor water quality. Under suitable meteorological conditions, cyanobacteria will reproduce in large numbers, which will consume dissolved oxygen in the water, affect the growth of other aquatic organisms, and release toxins into the water, seriously polluting the water. The chlorophyll concentration of the water body is the sum of the chlorophyll of all algae including cyanobacteria. The number of cyanobacterial cells only represents the number of cyanobacteria. When cyanobacteria grow in large numbers, the number of other algae in the water body will be suppressed, and biodiversity will decrease. Therefore, the chlorophyll concentration and the number of cyanobacterial cells in the water body can be used to quickly estimate biodiversity.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A rapid estimation method for algal biodiversity index in Class II water bodies.

[0007] (1) Use the Hach DS 5X water quality monitor to detect the water body in situ and obtain the chlorophyll concentration C and the number of cyanobacteria cells N;

[0008] (2) Using chlorophyll concentration C , cyanobacterial cell count N Constructing the index ,

[0009] ;

[0010] The unit of cyanobacteria cell count of Hach DS 5X water quality monitor is cells / ml. 1000N is to convert it into the commonly used unit cells / L. At the same time, because this value is too large and the order of magnitude difference with the chlorophyll concentration C is too large, the logarithm is taken to characterize the chlorophyll concentration of cyanobacteria; the chlorophyll concentration in the water body includes the chlorophyll concentration of cyanobacteria and the chlorophyll concentration of other algae. Therefore, the chlorophyll concentration of cyanobacteria can be obtained by subtracting the chlorophyll concentration of cyanobacteria from the chlorophyll concentration C, that is, The denominator of . It represents the ratio of the number of cyanobacteria to other algae. Since cyanobacteria have lower requirements for nutrient concentration, they are easier to grow in water bodies. When the number of cyanobacteria is large, the growth of other algae will be inhibited, leading to a decline in biodiversity. The 1.95 in the denominator is the adjustment The shape of the curve makes it linearly related to the Pielou evenness index and the Shannon-Wiener diversity index.

[0011] (3) Utilization Quick estimation of Pielou evenness index J , ;

[0012] (4) Pielou uniformity index J The size of the numerical value is used to judge the water quality. The larger the value, the better the water quality. 0~0.2 means the water body is eutrophic, 0.2~0.3 means mesotrophic, 0.3~0.5 means mesotrophic, and greater than 0.5 means oligotrophic.

[0013] Another option is,

[0014] (1) Use the Hach DS 5X water quality monitor to detect the water body in situ and obtain the chlorophyll concentration C and the number of cyanobacteria cells N;

[0015] (2) Using chlorophyll concentration C , cyanobacterial cell countN Constructing the index ,

[0016] ;

[0017] (3) Utilization Fast estimation of the Shannon-Wiener diversity index , ;

[0018] (4) Shannon-Wiener diversity index The value is used to judge the water quality. The larger the value, the better the water quality. 0-1 means the water body is eutrophic, 1-2 means mesotrophic, 2-3 means mesotrophic, and greater than 3 means oligotrophic.

[0019] Beneficial effects of the present invention:

[0020] The Hach DS 5X multi-parameter water quality monitor uses the fluorescence effect to detect the chlorophyll concentration (ug / L) and the number of cyanobacteria cells (cells / mL) in the water body, and constructs an index using the chlorophyll concentration C and the number of cyanobacteria cells N. , then linear modeling, using Quick estimation of Pielou evenness index J and Shannon-Wiener diversity index , through the uniformity index J and diversity index The water quality is evaluated by the size of the numerical value, which enables rapid on-site estimation and provides a basis for on-site evaluation of the health of water bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A 1:1 diagram of the Pielou uniformity index of each point calculated from the estimated value of the present invention and the microscopic examination result;

[0022] Figure 2 This is a 1:1 plot of the Shannon-Wiener diversity index of each site calculated based on the estimated values ​​of the present invention and the microscopic examination results. DETAILED DESCRIPTION

[0023] In April 2019, water samples were collected from five sites in Huahe River, Baima Lake, and the chlorophyll concentration (ug / L) and cyanobacterial cell count (cells / mL) of the water were detected in situ. The chlorophyll concentration was recorded as C , the number of cyanobacterial cells is recorded as NThe instrument used was a Hach DS 5X multi-parameter water quality monitor. After the water samples were collected and processed, the different species of algae were counted under a microscope, and the counting results were used to calculate the Pielou evenness index J and Shannon-Wiener diversity index at each point. , , , This is the ratio of the number of individuals of this species to the total number of individuals, and S is the total number of species in the community.

[0024] Using the formula Calculate the , using the formula Estimate the Pielou uniformity index of each point and make a 1:1 plot of the estimated value and the Pielou uniformity index calculated by microscopy results, see Figure 1 .Depend on Figure 1 It can be seen that the data points are concentrated near the diagonal line, which shows that the Pielou uniformity index estimated by the method of the present invention is relatively accurate and can meet the needs of practical applications.

[0025] Using the formula Calculate the , using the formula Estimate the Shannon-Wiener diversity index of each site and make a 1:1 plot of the estimated value and the Shannon-Wiener diversity index calculated by microscopy results, see Figure 2 .Depend on Figure 2 It can be seen that the data points are concentrated near the diagonal line, indicating that the Shannon-Wiener diversity index estimated by the method of the present invention is relatively accurate and can meet the needs of practical applications.

[0026] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for rapidly estimating the algae biodiversity index of Class II water bodies, characterized by: (1) Use the Hach DS 5X water quality monitor to detect the water body in situ and obtain the chlorophyll concentration C and the number of cyanobacteria cells N; (2) Using chlorophyll concentration C , cyanobacterial cell count N Constructing the index , ； (3) Utilization Quick estimation of Pielou evenness index J , ; (4) Pielou uniformity index J The size of the numerical value is used to judge the water quality. The larger the value, the better the water quality. 0~0.2 means the water body is eutrophic, 0.2~0.3 means mesotrophic, 0.3~0.5 means mesotrophic, and greater than 0.5 means oligotrophic.

2. A method for rapidly estimating the algae biodiversity index of Class II water bodies, characterized by: (1) Use the Hach DS 5X water quality monitor to detect the water body in situ and obtain the chlorophyll concentration C and the number of cyanobacteria cells N; (2) Using chlorophyll concentration C , cyanobacterial cell count N Constructing the index , ； (3) Utilization Fast estimation of the Shannon-Wiener diversity index , ; (4) Shannon-Wiener diversity index The value is used to judge the water quality. The larger the value, the better the water quality. 0-1 means the water body is eutrophic, 1-2 means mesotrophic, 2-3 means mesotrophic, and greater than 3 means oligotrophic.

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