Marine ecology conditions at Weda Bay, North Maluku based on statistical analysis on distribution of recent foraminifera

¹ Geological Engineering Diponegoro University, 50275 Semarang, Indonesia
² Deep Sea Research Centres-LIPI, 16003 Bandung, Indonesia

Abstract

Analysis of foraminifera in geology,usually being used to find the age of rocks/ sediments and depositional environment. In this study, recent foraminifera was used not only to determinethe sedimentary environment,but also to estimate the ecological condition of the water through a statistical approach.Analysis was performed quantitatively in 10 surface seabed sediment samples in Weda Bay North Maluku. The analysis includes dominance (Sympson Index), diversity and evenness (Shannon Index), and the ratio of planktonic -benthic. The results were shown in the plotting diagram of M-R-T (Miliolid-Rotalid-Textularid) to determine the depositional environment. Quantitative analysis was performed using Past software (paleontological version Statistic 1:29).The analysis result showed there was no domination of certain taxon with a moderate degree of evenness and stable communities and considerably a moderate diversity. The results of this analysis indicated that research area had a stable water conditions with the optimum level of carbonate content, oxygen supply, salinity, and temperature. The ratio of planktonic and benthic indicate the relative depth, which was deeper the water increased the percentage of planktonic foraminifera. Based on M-R-T diagram showed the distribution of sediment deposited on exposed carbonate (carbonate platform) environment with normal saline.