Forensic limnology

Forensic limnology is a sub-field of freshwater ecology, which focuses especially on the presence of diatoms in crime scene samples and victims.

Diatoms are diverse microscopic single-celled algae with silica cell walls, called frustules, that are abundant in freshwater and saltwater ecosystems.

[5][6] The reason diatoms are a common tool to match water environments is because of the variability of their populations are relatively predictable and constant, they can be identified by using a light microscope, and their silica cell walls allow for preservation and extraction from collected samples.

[1] Diatom profiles can only explain when or where evidence was found in some situations, and not the time of death if there is no body fluid sample available to be collected.

Without the inhalation of water and some circulation present in the victim, the diatoms will not be able to enter the alveolar system and bloodstream making it difficult to extract a reliable sample.

[2] Samples are taken from bone marrow, lung, spleen, liver, kidney, brain tissue, or from the area where the crime was discovered or occurred.

The presence of diatoms in air, food, drink, and close contact is not variable enough to be supportive evidence in determining locations of events.

Even so, an investigation requires the use of forensic limnology in order to estimate time of death, location of drowning, and the determining of suspect.