Evaluation of the ecological health of Suzhou Water based on the biological integrity index of large benthic invertebrates.

In order to promote the management and protection of urban water bodies, a survey of large benthic invertebrate communities was carried out on 23 river sections in Suzhou. On this basis, the core indicators suitable for urban water ecological health assessment were selected by analyzing the distribution range, discrimination ability and correlation of the candidate indicators. The ratio method was used to calculate the core index values, and the macrobenthic invertebrate biological integrity index value (Benthic Macroinvertebrate Index of Biotic Integrity, BIBI value) were obtained by accumulating and summing. The results show that 22 species of macrobenthic invertebrates were found in the Suzhou urban water and reference points, belonging to 3 phyla, 6 classes, 9 orders and 14 families. After screening, the BIBI that was suitable for evaluation of Suzhou was composed of the following 6 indicators: the total number of taxons, the number of arthropod taxa, the Shannon-Wiener diversity index, the percentage of widespread species, the percentage of individuals in the class of insects, and the percentage of individuals in pollution-tolerant groups. The optimal expected value of the calculated BIBI value is 4.01, even the BIBI value ≥ 4.01 is healthy, 3.01-4.01 is good, 2.01-3.01 is fair, 1.01-2.01 is poor, and <1.01 is extremely poor(the interval range is left closed and right open, and BIBI value ≥ 0). According to the results of BIBI, the ecological health of the water in Suzhou was uneven. There were more fair and good sites than healthy ; the health status of each point in different seasons is different. The correlation analysis between BIBI and various water quality factors proves that BIBI can be used to evaluate the ecological health of urban water and has scientific guiding significance for the evaluation of urban water ecological health. [ABSTRACT FROM AUTHOR]