Biological pollution potential in the water of Bintan-Riau Islands Province, Indonesia: First appearance of harmful algal bloom species

Abstract

The increased number of human population in coastal areas can be the common dominator of an event of harmful algal blooms (HABs), which might be of a negative impact on human activities. Generally, HABs occur due to the dynamics of some phytoplankton species. The objective of this study was to inventory the phytoplankton distribution in the water of Bintan-Riau Island in Indonesia. In the perspective of the pollution biology mitigation, phytoplankton samples were collected from 4 to 5 composited sub-samples of the seven sites around the Bintan water (Dompak, Kijang, Kampung Baru, Lobam, Trikora, Tanjung Unggat and Senggiling). The investigation revealed the presence of 41 phytoplankton taxa. Bacillariophyta was the dominant group of phytoplankton in the coastal waters of the Bintan Island. The highest abundance of phytoplankton is found in the Dompak and Senggiling waters with the number of phytoplankton per mL reached 1.846.667 and 2.050.667 cells/mL, respectively. Both stations had the highest number of phytoplankton species (26 species) compared to other stations. The harmful phytoplankton group found was dinophyceae (genus Ceratium), which was observed in almost all the coastal waters of Bintan Island. The highest abundance of dinophyceae was in the waters of Kampung Baru, Lagoi. In this study, HABs proliferation was associated with nitrate concentration, which recorded high values in all the observation sites. An eutrophication study is needed to understand the broader complexity of nutrient effects governing the occurrence of HABs in the coastal areas, which can help in the mitigation of problems caused by HABs, particularly in Dompak and Senggiling stations. Keywords: Bintan Island, Phytoplankton, HABs, Ceratium, Bacillariophyta, Eutrophication