While several methods for determining postmortem submersion
interval (PMSI) in drowning cases have been suggested,
the estimation of PMSI remains difficult. Next-generation
sequencing (NGS) technology enables simultaneous
identification of multiple taxa from environmental samples.
Although NGS has been applied to estimate time since death,
this application has been mainly focused on terrestrial cases.
As a case study, we investigated microeukaryotic biodiversity
and community structures in submerged car bonnet and
drowned pig using NGS technology. NGS analysis showed
that the microeukaryotic biodiversity in pig carcass was relevantly
lower than that in car bonnet. NGS results also revealed
that water molds and algae were related to decomposition.
Relative abundances of Filobasidium, Achlya, Saprolegnia,
Hydrodicton, Lobosphaera, and Scenedesmus varied
with decomposition period. This data indicated that these
taxa might be useful as good indicators to estimate PMSI.
This study showed microeukaryotic community analysis using
NGS technology may help solve drowning cases in forensic
investigation.