Biological Evaluation of Water Quality for Benthos in Typical Rivers of Eastern Jilin Province

Benthos are aquatic organisms living at the bottom of water bodies for all or most of their life history. Apart from the settled and moving living, their forms of habitat are mostly attached to the hard substrate like rocks or soft bases such as mud and sand. In addition, there are benthic species that attach to the plant surfaces or other benthic animals, and inhabit the intertidal zone. In terms of feeding methods, most benthic animals feed on suspended matter and sediment. Most of them are invertebrates and are a complex ecological group. According to the size, they can be divided into macrobenthos and meio-benthos [1]. Benthos are an important part of the water ecosystem. Using a typical river (Gaya River) in eastern Jilin Province, this paper analyzed the water quality, the components of benthic organisms and their biological density through sampling surveys of three typical locations in the upper, middle and lower reaches of the Gaya River. In addition, it made a biological evaluation of the water quality of the Gaya River.