Iranian Biology Society Journal of Animal Research (Iranian Journal of Biology) 2383-2614 33 3 2020 09 22 Qualitative monitoring of Kharrood-Disam River in Guilan province with the help of biological indices of macrobenthos during the period of 20 years from 1999 to 2017 Qualitative monitoring of Kharrood-Disam River in Guilan province with the help of biological indices of macrobenthos during the period of 20 years from 1999 to 2017 180 194 1691 FA Ehsan Asadisharif Javid Imanpure Department of Fisheries Sciences, Faculty of Natural Resources, University of Guilan,Iran 0000-0002-5090-9170 Journal Article 2019 05 18 The present study was carried out with the purpose of biological monitoring and self-purification of the Kharrood-Disam river and the impact of time on this river with the help of the macroinvertebrates. Macroinvertebrate samples were taken using Surber’s sampler with 3 replicates in each sampling. In the first period of sampling 5 orders and 14 families, and in the second period of sampling, 5 orders and 9 families were identified.The mean EPT richness in the first sampling period was 61.42, which was categorized in "high quality" and in the second sampling period was 12.64, which was categoried in "relatively good quality".The results of the Halnesinoff biological index showed that during the first period of sampling the river had a relatively good condition (HFBI=5.22) and the best conditions were observed at the third station of the fall season (HFBI=3/14). Also, the status of this indicator during the second period of sampling has a good trend and is in excellent condition at most stations(HFBI=1/45). The results of determining the correlation of each of the environmental factors with macrobenthos and environmental factors with each other by the (PCA) in the CANOCO for Win5.0 software revealed parameters such as pH and BOD in the spring and parameters such as temperature and EC in the season Summer was the most important variables. The results of the combination of biological indicators in the River showed that during the 20 years the river has been able to self-purification pollutants such as rainbow trout farm waste. The present study was carried out with the purpose of biological monitoring and self-purification of the Kharrood-Disam river and the impact of time on this river with the help of the macroinvertebrates. Macroinvertebrate samples were taken using Surber’s sampler with 3 replicates in each sampling. In the first period of sampling 5 orders and 14 families, and in the second period of sampling, 5 orders and 9 families were identified.The mean EPT richness in the first sampling period was 61.42, which was categorized in "high quality" and in the second sampling period was 12.64, which was categoried in "relatively good quality".The results of the Halnesinoff biological index showed that during the first period of sampling the river had a relatively good condition (HFBI=5.22) and the best conditions were observed at the third station of the fall season (HFBI=3/14). Also, the status of this indicator during the second period of sampling has a good trend and is in excellent condition at most stations(HFBI=1/45). The results of determining the correlation of each of the environmental factors with macrobenthos and environmental factors with each other by the (PCA) in the CANOCO for Win5.0 software revealed parameters such as pH and BOD in the spring and parameters such as temperature and EC in the season Summer was the most important variables. The results of the combination of biological indicators in the River showed that during the 20 years the river has been able to self-purification pollutants such as rainbow trout farm waste. https://animal.ijbio.ir/article_1691_8303a79b1e19a194f1875981be5bdb6f.pdf