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Nujiang is one open the rapids habitats international rivers , the Nujiang River refers of Gongshan to Baoshan about 620km section of the river , to Lushui sector is divided into two world-class zoogeographical regions - Qinghai-Tibet Plateau and Japan District . The field survey was conducted in July 2004 , the middle and upper reaches of Nujiang , investigated a total of 65 sampling points . In this paper, based on historical data and the July 2004 site visit data , and preliminary analysis of the Nujiang fish biological integrity index (Index of BioticIntegrity, IBI) . The main results are as follows : 1 , according to the actual situation of the Nu River fish , from five species composition and abundance , tolerance, trophic structure , reproduction and co - bit group and fish populations and health status , selected 18 candidate indicators , and the combination of the Nujiang fish resource status and historical data , to select the 10 indicators from candidate indicators established the the fish IBI evaluation system for the upper and middle reaches of the Nujiang . Indicators score to take a 1,3,5 score IBI total score is calculated as follows : index score and / indicators of the number 12 . 2 , site survey is divided into of Gongshan , Fugong , Liuku , Baoshan four river segments , IBI evaluation according to the survey data , the results show that the the Fugong level best , followed by Liuku , Baoshan and Gongshan relatively poor . The upper reaches of the Nujiang River the overall IBI in good condition , by human disturbance . Nu River upstream fish IBI evaluation results show that the region suffered major influence habitat types , food organisms and other natural factors , the impact of human activities on the upper and middle reaches of the Nujiang focused section of the river in Baoshan .
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