STRUKTUR KOMUNITAS ZOOPLANKTON DI SEI SIKAMBING KOTA MEDAN, SUMATERA UTARA

Abstrak

Zooplankton is a water organism that plays an important role in the food chain. Sei Sikambing is an habitat for water organisms and a place of various human activities. The purpose of the research is to find out the abundance, diversity index, uniformity, dominance index and state of physico-chemical properties in the river Sei Sikambing City of Medan, North Sumatra. The research was conducted from March to May 2024. This type of research is Causal Comparative Research which is ex post facto based on the environmental conditions of river waters. There are nine genus of zooplanktons: Fritillaria, Lucifer, Dadaya, Cyclops, Pariambus, Lecane, Conochilus, Rotaria, Difflugia and a class of Crustacea that are Porcellanides larvae. The zooplankton abundance value at station I was 6.9, at station II was 1.8 and at station III was 0. The diversity index (H’) value for zooplanton belongs to the medium category with the highest value at the station I being 1.8. The zooplankton uniformity index value at station I was 0.81, at station II was 0.43 and at station III was 0. The value of the physical-chemical properties belongs in good condition with the results of the measurement of the water temperature obtained a value of about 25°C - 27°C, the brightness of water about 28cm - 35,25cm, pH about 5,81 - 7,41, the DO value about 4,09mg/l - 5,13mg/L, the BOD value about 2,6mg / l - 3,1mg / L and the COD value around 25mg/ l - 7,1mg/ L. The condition of the physicochemical parameters at the time of the research still supports the life of plankton.