The impact of environmental variables on the amount of fouling in fish cage farms in the region Ayush of Khorramabad

Fouling are highly divers and ubiquitous, and constantly correlate with environmental variables, and one of the largest global problems in cage culture. The present study was conducted to evaluate effects of environmental parameters on abundance of fouling cages fish culture of rainbow trout in Ayush dam of Khorramabad from winter 2016 to autumn 2016. The samples were collected from net panels(0.0625 m2) that attached to the PVC frame, located at a depth of one meter from  the side of the fish culture cages, and wet weight was measured, then it was identified with valid authentication keys. In this study 3 genera of green algae and diatom were identified. The analyses showed that DO, temperature, pH, turvidity and electrical conductivity were positively correlated with the genus Naviculaceae from diatoms and (Tetrasporaceae, Chlamydomonadaceae) from green algae. The temperature and pH were positively and significantly correlated with Tetrasporaceae and Naviculaceae, wet weight and Algae cover percentage. The high level of fouling due to environmental factors, especially temperature and pH  made it necessary to clean the nets once a month in summer.