Environmental DNA reveals aquatic biodiversity of an urban backwater area, southeast coast of India.

Strong conservational management needs comprehensive data on the status of
biodiversity. However, effective methods to document aquatic biodiversity
are either lacking or less in use. Environmental DNA (eDNA), often
released by the organisms into the environment (e.g. water, soil) offers a
great opportunity for examining the biota in aquatic ecosystems. Here, we
have conducted a metagenomics study on eDNA sample collected from
Muttukadu, Tamil Nadu, India to portray the biodiversity in a backwaters
featured environment. Shotgun metagenomic approach with Illumina® NextSeq
500 sequencing yielded 88.4 million raw reads. The processed clean data
were assigned as 80% prokaryotes, 0.4% eukaryotes, ̴ 2 % viruses and ~ 17
% remain as unknown or un-identified. Using this approach, we detected 112
families across the major phyla of eukaryotes. The approach has the
potential to discover small micro-eukaryote, unseen species and, our data
represents major phyla from both estuarine and marine environments.
 This includes phyla that are of conservational significance and
ecologically sensitive. Given the sensitivity, efficacy, and the
cost-effectiveness of the method, we suggest this tool for an introductory
understanding of biodiversity structure in a backwater environment during
biomonitoring assessments.