STUDY ABUNDANCE PLANKTONIC DIATOM (Bacillariophyta) WITH NITRATE AND PHOSPHATE CONCENTRATION IN BELAWAN WATERS PROVINCE NORTH SUMATERA

Abstract

Research about abundance of planktonic diatoms with concentration of
nitrate and phosphate in Belawan waters of North Sumatra Province was
conducted in February 2013. The purpose of this study was to know the type of
planktonic diatom, nitrate and phosphate concentration, diatom community
structure, determine the relationship between nitrate and phosphate concentration
with Abundance of diatoms. Samples taken from 4 stations. The sample
identification was obtained by 16 diatom species. The abundance of diatoms is in
the range of 4,018-4,802 ind/liter. The nitrate concentration of each station is in
the range of 0.261-0.507 mg/l. The concentration of phosphate in the range of
0.064-0.126 mg/l. The diversity index is moderate, no dominant type and the
uniformity index belongs to the still-balanced waters. The relationship of nitrate
and phosphate concentration to diatom abundance is classified as moderate to
positive value, the higher the concentration of nitrate and phosphate, the higher
the diatom abundance.
Keyword: Belawan Waters, Diatom, Abudance, Nitrate & Phosphate