Ecology

Forensic Ecology is the use of environmental evidence types to assist in investigating crime, both outdoors and indoors. The most common areas of forensic ecology that you will encounter are forensic diatomology, forensic entomology, and forensic botany and palynology (pollen)

Forensic Diatomology

**We are extremely competetive with our high quality forensic diatomology service.  Most work is commenced on receipt of items.  We provide written reports within oneweek of work being carried out**

What are diatoms?

Diatoms are algae, microscopic unicellular plants, which can be found in saltwater, freshwater, soils and damp surfaces. They are very diverse with over 100,000 species known. They have a unique silica cell wall called a frustule which makes them very robust and they can withstand harsh conditions. As they are classed as algae, they rely on the sun for their energy and as such are found in well-lit surface layers of water. When diatoms die, their skeletons sink to the bottom layers of water.

How can we use them?

It is not always possible to determine the cause of death during a post mortem examination when a body has been found in water. The presence or absence of diatoms within the body can assist. There are two types of drowning:

• Type 1: "Dry Drowning"
  Cold water is inhaled and hits the back of the throat causing laryngeal spasm and vagal inhibition (cardiac arrest). No diatoms are found within the body as water does not get drawn into the lungs.

   

  Type 2: "Common Drowning"
  Water carrying diatoms is inhaled into the lungs - this can be as much as 250ml. Air sacs in the lung lobes burst and water containing diatoms enters the bloodstream. The heart continues to pump circulating diatoms around the body to all organs. The presence of diatoms within the body suggests the person was alive when they entered the water and that drowning was the cause of death or played a significant part in the cause of death.

NOTE: As diatoms cannot pass through the gut wall, diatoms swallowed in food or in the process of drowning will not enter the bloodstream.

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Forensic Entomology

What is forensic entomology?

Forensic Entomology is the use of insects to assist in legal investigations, the vast majority of which are suspicious deaths or murders. The most commonly encountered insects are blowflies, but other flies and beetles are often found. Blowflies are especially useful to the investigator as they are most often the first invaders of decomposing material. When temperatures are warmer, blowflies can begin laying eggs on a body within a few hours. When temperatures are cooler, or if the body is concealed, such behaviour may be delayed or impeded.

In cases where a body is enclosed, for example within a container or in a grave, a blowfly infestation may be prevented. Under these circumstances, other, smaller flies may be the first to infest a body.

How can we use it?

We can determine the following from insects:

•An estimated post-mortem interval (PMI);
•Whether or not a body has been moved from one location to another;
•Whether a body has been moved between a concealed and exposed environment;
•Abuse and neglect;
•Public health issues.

This evidence type is one to consider not only when you can see an infestation but also when you suspect an individual has been dead for some time. There may even be an infestation present that you can't see. Additionally, if it is unknown whether a death is suspicious, it is better to collect the insects as it is almost always not possible to go back at a later stage when this evidence has become indispensable to the case.

To ensure the most relevant samples are collected it is recommended to call upon the expertise of a trained forensic entomologist who can efficiently collect them for subsequent analysis.

We offer a full scene and laboratory service in forensic entomology and also review the findings in cases where the entomology has been conducted by another forensic scientist.

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Forensic Palynology

What is Forensic Palynology?

Forensic palynology utilises pollen, spores and other microscopic particles. Pollen grains are produced by seed bearing plants, flowering plants and cone-bearing non-flowering plants, whilst spores are produced by ferns, mosses, algae and fungi. Palynology also comprises the study of other microscopic entities such as insect and plant remains, particularly microcharcoal (microscopic particles of charred plant material). Collectively these are referred to as palynomorphs.

Pollen is seasonally and geographically sensitive and is dispersed by water, wind and insect activity throughout the year. It settles on surfaces in much the same way as dust and is invisible to the naked eye. In the same way that fibres are trace evidence and can be transferred from one surface to another through contact, pollen may be collected on shoes, clothing and tyres, for example, when in contact with soils and vegetation. In addition, airborne pollen collects in the nasal cavities as we breathe. An experienced palynologist can identify individual pollen grains and spores and reconstruct a habitat from a pollen assemblage of samples collected.

How can we use it?

Pollen evidence can be used to:

• Link people, vehicles, and objects to a scene or deposition site;
• Identify habitats or geographical locations relevant to police investigations;
• Prove or disprove alibis;
• Help determine the fate of an individual prior to death;
• Assist in determining the season and location in which an individual died;
• Help determine possible locations of a missing person by looking at the clothing of a suspected offender;
• Assist in determining the country of origin of illicit drugs

Again, we offer a forensic palynology scene and laboratory service as part of our forensic ecology department in addition to a review service in this area.

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Tel: 0845 371 2486