Distribution of phytoplankton diversity and abundance in Mahakam Delta, East Kalimantan

The Mahakam Delta typically consisting of several ecosystems has been identified as one of biodiversity hotspot in Kalimantan Island. In order to provide phytoplankton distribution, diversity and abundance data, a research on 4 stations representing delta plain (ST1) and delta front (ST2, ST3, ST4) was performed. The studies describe phytoplankton community existing in this region and multivariate analysis using correspondent analysis (CA). There were 48 taxa phytoplankton belonging to Bacillariophyceae (35), Dinophyceae (6), Chlorophyceae (4), and Cyanophyceae (3). The highest taxa occurred in ST3 with diversity index of 2.09, followed by ST2 (1.95), ST1 (1.15), and ST4 (0.9). Diversity index of ST3, ST2, and ST1 delta was categorized as moderate stable community, while ST4 was categorized as unstable community. Bacillariophyceae was not only as the highest diversity class but also as the highest abundance, recorded in ST3. The abundance class ranged 1.4x105 cell/m(3) to 2.2x106 cell/m(3). Generally, phytoplankton diversity and abundance in delta front was higher than that in delta plain. Human activities and physical process likely influenced diversity and abundance of phytoplankton in Delta Mahakam. (C) 2016 The Authors. Published by Elsevier B.V.