Marine environment harbours millions of bacterial genera, and the bacterial dynamics in terms of relative abundance and richness varies for temporally and geographically distinguished marine samples. The present study unearthed the unexplored bacterial diversity of co-occurring marine samples (Rhizosphere sediment, Marine sediment, Seawater, Seaweed and Seagrass) from uncharacterised coastal region of Karankadu, Palk Bay, India. A detailed work is carried out to study whether the co-occurring marine samples harbour similar bacterial community composition since they are neither temporally nor geographically distinguished to each other. To gain more insight to this, a total of 22.44 million paired end reads (V3 region of 16S rRNA gene) were obtained from the five marine metagenomic DNA through Illumina bar code sequencing. The bacterial community composition in all the five marine samples varied from sample to sample. Though, most of the bacterial taxa at phylum level were unvaryingly found in all the marine samples, the bacterial community composition at higher taxonomic level differs from one sample to other. This is the first study that provides plethora of information about the bacterial community composition in the unexplored marine system through high throughput sequencing approach that contradicts with the general notion that bacterial diversity in co-occurring marine samples are similar to each other. Moreover the presence of 62-71% of rare species in all the sample revamps the fact that even rare microbiota plays an important contribution to the bacterial community composition and ecological maintenance of a particular niche