Physico-Chemical Characteristic of Sediment in Teluk Kaping, Bali: It’s Correlation with Bacterial Composition and Abundance.

Abstract

The objectives of this study were to determine the physico-chemical of the sediment in Teluk Kaping Bali., which is has closed topography and has been utilized for intensive Mari culture activities. Those activities influence the environmental condition. Samples (sediment) in this study came from 16 observation sites. Sediment has a stable characteristic. Its condition could be pointed by the physico-chemical characteristic and the bacterial composition and abundance. Physico-chemical characteristics of the sediment were analyzed using Correlation and Principal Component Analysis, whilst its impact to bacterial composition and abundance were determined using the Multiple Regression. Those analyses were using Minitab 2003 13.2 Version. The physical characteristics showed that the sediment were dominated by sand and clay fraction, meanwhile in the coast area there was also found silt fraction. The pH was alkaline (7.9-8.6). It also has reductive condition, with redox potential between -242.90 mV s/d -56.50 mV. The interstitial water (IW) was 28.85 – 60.49%. Total carbon was (C) 0.13 – 21.6%, nitrogen (N) 0.04 – 0.19%, and phosphor (P) 0.0004 – 0.003%. The C/N/P ratio has a high value, also the C/N ratio has a high value in the sediment, with high ratio variety. C/P ratio variety was higher than the C/N and N/P ratios. Identified bacteria from heterotrophic group, such as Enterobacter spp., Bacillus spp., and Pseudomonas sp., and nitrified bacteria (Nitrosomonas sp., Nitrosococcus sp., and Nitrobacter sp.) were dominantly found in the sediment. Meanwhile, there were also a small number of other identified bacteria from the Enterobacteriaceae group, such as Escherichia coli and Klebsiella sp. Bacillus spp. has the highest abundance, which is almost 60% of total identified bacteria abundance. Heterotrophic bacteria were more dominant than the nitrified bacteria in the sediment. This is related to the ability of the heterotrophic bacteria to utilyze different of nutritional sources, efficiently. It also has a broad environmental tolerancy. Statistical analyses pointed out that the physico-chemical charateristics has unsignificant correlation to the bacterial composition and abundance in Teluk Kaping sediment. This is caused by the characteristic of each bacterium that has an ability and special survival mechanism from limited nutrition and poor environmental condition.