Environmental DNA (eDNA) is genetic material released by organisms into their surroundings, through skin cells, mucous, faeces, gametes, or decompositing tissue. In aquatic environments, this DNA becomes suspended in the water column, for example, and can be captured through water sampling.

By extracting and analysing eDNA, Taxa Genomics can determine which species are present in a river, lake, pond, estuary, or marine site without needing to physically observe or capture them.

This approach is transforming biodiversity monitoring by making it:

• Non-invasive: samples can be taken without disturbing wildlife
• Sensitive: detects species that are rare, elusive, or present at low density
• Scalable: a single survey can provide information on one species or an entire community

Professional eDNA surveys like the ones offered by Taxa Genomics follow standardised procedures to ensure the results are reliable and repeatable:

A. Sample Collection

• Water samples are collected in sterile bottles or with field kits
• Sampling protocols are designed to minimise contamination and maximise representativeness

B. DNA Capture and Preservation

• Water is filtered through specialist membranes to trap DNA fragments
• Filters are preserved using buffers to prevent degradation

C. Laboratory Processing

• DNA is extracted from the filters
• Depending on the project objectives, either targeted tests or broad community metabarcoding is carried out.

A. Targeted detection (qPCR, TaxaScreen)

• Used when monitorig for a specific species, such as Great Crested Newt, or Signal Crayfish.
• Relies on species-specific primers and probes to detect trace amounts of DNA
• Results are reported as DETECTED or NOT DETECTED
• Advantages: highly sensitive, cost-effective, suitable for regulatory monitoring

B. Metabarcoding (Community-level surveys, TaxaReveal)

• Uses "universal" primers to recover DNA from many different species in a single sample
• High-throughput sequencing provides a list of species present in the environment
• Useful for biodiversity assessments, ecological baselines, and monitoring changes over time.
• Advantages: Comprehensive and efficient, delivering community-wide data from a single survey.

• Regulatory compliance: e.g. Great Crested Newt surveys under UK and EU legislation
• Biodiversity monitoring: assessing fish, amphibian, or invertebrate communities in rivers, lakes, estuaries, and marine systems
• Invasive species detection: early warning for non-native species before they become established
• Conservation management: identifying priority habitats, rare or declining species, and evaluating restoration success
• Baseline surveys for development projects: providing evidence for environmental impact assessments

• Contamination control: rigorous field and laboratory protocols are essential and at Taxa Genomics we include controls at every possible stage
• DNA persistence: eDNA usually reflects species present within the last few days to weeks, depending on conditions.
• Detection vs abundance: eDNA can confirm presence but does not always translate directly into population size
• Data interpretation: species lists need to be considered alongside ecological context, reference databases, and survey design