Seasonal Variation of the Composition and Density of Phytoplankton in Inner Ambon Bay

Abstract

Seasonal variation of conditions in Ambon Bay affected the existence of phytoplankton organisms. These organisms are the dominant pelagic primary producers that convert inorganic substances into organic compounds through the photosynthetic processes. This study aims to determine the composition, density, and distribution of phytoplankton in relation to the characteristics of the waters. Phytoplankton sampling was conducted vertically in the euphotic zone by using a plankton net KITHARA every month from June 2011 to May 2012. This study found 4 classes of phytoplankton which consist of Bacillariophyceae (38 genera), Dinophyceae (13 genera), Cyanophyceae (1 genus), and Chrysophyceae (2 genera). Genus Trichodesmium, Cyanophyceae class dominated waters in East Season, Transition Season II, West Season and Transition Season I. ANOVA test of the abundance of phytoplankton obtained significant differences in the distribution of the both temporal and spatial, the correlation of the physical and chemical characteristics of the waters with an abundance of phytoplankton showed that East Season dominated by Gonyaulax (Dinophyceae) and Bellerochea (Diatom) which is influenced by phosphate, silica, ammonia, turbidity, pH and DIN:DIP. Transition Season I and West Season dominated by Triceratium, Skeletonema, Bacillaria, Planktoniella, Ditylum, DiploneisandProrocentrum are affected by temperature, salinity, nitrite, ration of dissolved inorganic nitrogen to dissolved silicon, secchidepth and euphotic zone.