Understanding eDNA in Water Sampling

What eDNA Is

Environmental DNA (eDNA) refers to the genetic material that organisms shed into their environment. This includes cells, skin flakes, feces, and other biological materials.

In aquatic ecosystems, eDNA can be used to identify species present in a water body without needing to capture or observe them directly.

How eDNA Spreads Through Water

When an organism dies or sheds cells, its genetic material enters the surrounding water. This DNA then diffuses and decays over time.

The spread of eDNA can be modeled using diffusion equations, where the rate of decay depends on factors like temperature and water flow.

Decay and Detection

eDNA does not last indefinitely in water; it degrades due to enzymatic breakdown and photolysis. The rate of this degradation is influenced by environmental conditions such as pH, temperature, and light exposure.

Detection limits are critical for accurate sampling. If the concentration of eDNA falls below a certain threshold, it may no longer be detectable with current technologies.

Implications for Sampling

Understanding how eDNA spreads and decays helps in designing effective sampling strategies to ensure reliable detection.

The spread and decay patterns can also inform the timing of sample collection, as well as the volume of water that needs to be sampled.

Frequently asked questions

Try it live

Everything above runs in your browser — open eDNA Water Sampling Simulator (2D) and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.