Forensic Entomology in Aquatic Environments

Forensic Entomology in Aquatic Environments

Author: Mohini Chauhan, Amity University, B.Sc Forensic Science 

INTRODUCTION

Forensic entomology plays a crucial role in the field of investigation for legal purposes especially in determining the post-mortem interval or in short PMI or time of death. It is the study of insects.

We face some problems when it comes to entomological investigation in aquatic environment as it presents unique challenges and opportunities for forensic investigations. 

Estimation of time of death is a major factor but what happens when the body is found in the aquatic environment or submerged after several months or after long time. In this situation the forensic entomology plays a pivotal role and after the 72 hours, it is usually preferred and is most accurate. Some of the Aquatic insects are usually found in their growing and feeding stage as they sow reproductive stage in the terrestrial environment and thus, we can only find pupae, larvae or other immature stages on the corpse found in the aquatic environment but during the warmer season we may also found newly emerged adult on the corpse. There are many factors which can affect the insects finding on the corpse like water temperature, salinity, and presence of other organisms. Some of the insects which arrives first at the corpse are the species of flies and the crustaceans.

STAGES OF DECOMPOSITION IN WATER

The decomposition stages in the aquatic environment are divided into several stages:

First stage – submerged fresh

When a body first enters the water, it initially sinks and remains submerged. At this stage, there

are few visible signs of decomposition, as the body is still relatively intact. Aquatic insects may begin to explore the body, but colonization is minimal in this early stage. Fish and other aquatic animals may start to scavenge soft tissues.

Second stage – early floating

As decomposition progresses, bacterial activity within the body produces gases, causing it to become buoyant and rise to the surface. The skin may start to exhibit signs of discoloration and bloating.

Third stage – floating decay

The body remains at the surface, and decomposition becomes more advanced. Gases continue to accumulate, leading to extreme bloating. The skin may start to peel away, and fluids begin to leak from the body.

Fourth stage – floating remains

As the body continues to decompose, it may start to break apart. Soft tissues deteriorate rapidly, leaving only bones, cartilage, and other durable materials. The body may lose buoyancy and begin to sink.

Fifth stage – sunken remains

In the final stage, the body, or what remains of it, has sunk to the bottom. Decomposition slows significantly in the cooler, low-oxygen environment of the deep water. Bones and other hard tissues may remain intact for extended periods.

REFRENCES

1. RW Merritt, JR Wallace - Forensic entomology, 2009 - api.taylorfrancis.com (GOOGLE

SCHOLAR)

2. S Sharma, R Singh - laikndh, 2014 - academia.edu (GOOGLE SCHOLAR)

3. DB Rivers, GA Dahlem - 2022 - books.google.com (GOOGLE SCHOLAR)

4. N MacDonell, G Anderson - 1997 - publicsafety.gc.ca (GOOGLE SCHOLAR)