Environmental DNA as a tool for detecting illegal wildlife trade

Area of Science:

• Forensic Science
• Conservation Biology
• Molecular Ecology

Background:

• Illegal wildlife trade threatens species persistence and conservation efforts globally.
• Current wildlife forensics primarily relies on visible trace evidence or tissue samples.
• A gap exists in detecting wildlife presence on common objects lacking visible biological material.

Purpose of the Study:

• To investigate the utility of environmental DNA (eDNA) techniques for detecting trace wildlife DNA on non-biological substrates.
• To assess the persistence of trace DNA on common materials used in wildlife trafficking.

Main Methods:

• Exposure of plastic and fabric objects to turtles for one hour.
• Sampling of objects using swabbing techniques at various locations.
• Analysis of swab samples for the presence of turtle DNA using eDNA methods.
• Monitoring DNA detectability over a six-month period.

Main Results:

• Trace turtle DNA was successfully detected on both plastic and fabric objects with high confidence.
• DNA was detectable for at least six months post-exposure, indicating long-term persistence.
• Detection probability was not significantly impacted by sampling location or swabbing method.
• While DNA concentrations varied between substrate types, detection outcomes remained consistent.

Conclusions:

• Environmental DNA (eDNA) offers a powerful, non-invasive method for detecting wildlife presence on common objects.
• This technique provides a valuable tool for law enforcement in combating illegal wildlife trade by identifying potential contact with wildlife.
• The long-term DNA persistence suggests a significant window for forensic analysis under typical storage conditions.