Community structure of periphyton at floating net cages and non-floating net cages in Laut Tawar Lake, Aceh Tengah

Abstract Many activities are carried out around the Laut Tawar lake, one of which is cultivation floating net cages that can contribute nutrients to waters. One organisms take advantage abundance in waters periphyton. This study aims examine community structure periphyton as natural food Lake. research was conducted January-April 2022. The results showed there 9 classes at KJA station, namely Bacillariophyceae, Chlorophyceae, Cyanophyceae, Rhizopoda, Dinophyceae, Euglenophyceae, Trebouxiophyceae, Klebsormidiophyceae and Coscinodiscophyceae. While, non-KJA stations 7 where class dinophyceae not found stations. highest station on 7th day with a value 108,655 cells/cm 2 24,552 . lowest occurred 14 both Periphyton diversity index ranged from 1.88-2.76, moderate. evenness species ranging 0.61-0.75 classified high, while dominance 0.09-0.24 low. Based values obtained, artificial substrates areas Lake experienced moderate ecological stress stable condition. t-test obtained had difference greater than