ANALISIS STRUKTUR KOMUNITAS DIATOM PLANKTONIK DI PERAIRAN PULAU TOPANG KABUPATEN KEPULAUAN MERANTI PROVINSI RIAU

Abstract

This research was conducted in December 2013 at Topang island waters, Meran-
ti Islands Regency, Riau Province. The study observed the structure of planktonic di-
atoms community as well as the nitrate and phosphate concentrations of its adjacent
water. Four blocks were established during the study which located on the west, east,
north and southern part of the island. The study recorded 5 genera of centrales diatoms
and 4 genera of penales diatoms. The nitrate concentration ranged from 0.118 – 0.287
ppm, while phosphate concentration ranged from 0.049 – 0.142 ppm. The highest
abundance of diatom was founded in the west site of Topang island (1582.25 ind/L)
and the lowest was in southern site of Topang island (969.41 ind/L). Chaetoceros and
Nitzschia were appeared as with the highest abundance. The study concluded that
Topang waters were categorized as oligotrophic waters.