Diatomological mapping of water bodies of Delhi region for forensic consideration

Diatoms are photosynthetic algae; having a siliceous cell wall known as ‘frustule’. They are abundantly found in every aquatic and terrestrial environment including both fresh and marine water. They are cosmopolitan in nature as these microalgal species are also capable of growing on moist substrates like soil and bark of a plant. The growth of diatoms is very specific to the environmental conditions of a place due to which they are regarded as principal indicators of ecological status of the ecosystem. In forensics also, they play a crucial role in determining the mode and manner of death in cases of drowning. These small entities act as supportive evidence to detect the type of drowning; whether the death of a victim was due to antemortem or postmortem drowning. The diatomological mapping (D-mapping) of water bodies is an essential feature to generate a systematic record of diatom diversity present at a particular site of an aquatic body. The aim of our study is to conduct D-mapping of several regions of Delhi in order to generate a systematic record of diatoms present therein. The results of our study showed about 20 diatom species, some of them were commonly present at all sites, whereas few among them were site specific. The diatom database generated from D-mapping of water bodies can be used as a reference by the forensic pathologists while solving drowning cases, if any, from these aquatic bodies.