Foraminifera spatial analysis as bioindicator in Java Sea to Flores Sea

Abstract

Foraminifera is potential bioindicator to understand the modern and ancient marine environment and have been widely used as bioindicator. Java Sea to Flores Sea are productive area influenced by physical and chemical reactions from nature and human activity, so that their characteristics are important to recognize. The aim of this research is to determine oceanography condition of Java Sea to Flores Sea covers the depth, temperature, thermocline, and upwelling according to foraminifera analysis. The method used were inventory and species analysis from 12 stations along study area. The analysis was conducted based on species and abundance. Foraminifera species which are warm water bioindicators are Globigerinoides rubra and Globigerinoides sacculifera, upwelling bioindicators are Globigerina bulloides and Globorotalia menardii, and shallow thermocline bioindicators are Pulleniatina obliqueloculata and Neogloboquadrina dutertrei. The result show that Java Sea has more benthonic species and abundance because of its shallow depth while Flores Sea has more planktonic species and abundance because of its deep depth and part of open ocean. In Flores Sea the abundance of warm water species bioindicators fall significantly and high abundance of upwelling and shallow thermocline species bioindicators indicates that there are upwelling phenomenon with shallow thermocline, thin mix layer, and high productivity.