Monitoring on Zarin Gol River health using SIGNAL index

Degradation of rivers and the associated loss of biodiversity reduces ecosystem health and water quality. One of the best practical approaches to understand ecological status of a water body and determine impacts of human activities in reducing water quality is the use of benthic macroinvertebrates as evaluation tools for monitoring their biological integrity and health. The aim of this study was to evaluate the health of Zarin Gol River using SIGNAL index. Macroinvertebrate samples were taken using Surber sampler (an area of 900 cm2) with 3 replicates in 4 sampling sites (upstream, entrance of fish farm, forest area) in winter and spring seasons on Zarin Gol River. The total number of abundance of macroinvertebrate were counted 1971 belonging to 8 order, 19 families. The result showed that SIGNAL index among all stations are same and lies in quadrant a. but SIGNAL 2 score result indicates that station 3 lies in quadrant b. In general, based on the results of the distribution of macroinvertebrates and biotic index, the influence of these factors on Zarin Gol river is quite evidence and the stations that were affected by a variety of effluents (2, 4) had undesirable conditions in the studied river.