Environmental deoxyribonucleic acid, also known as environmental DNA or EDNA, is a method of surveying distribution patterns and population sizes for species within an ecological community. eDNA makes use of genetic deposits that organisms leave behind. Ecologists use hair, fecal matter, feathers and any other forensic like evidence that they can find in an environment. Using EDNA to sample populations is minimally invasive, and does not involve extracting genetic material directly from the targeted organisms. Anthropogenic disturbances continue to plague ecosystems the world over, affecting species abundance, species variety, migratory patterns and habitats.
Advantages of EDNA in Conservation
Without biodiversity measurements, conservations can’t know how which species are being lost, or how species populations change over time. Measuring biodiversity is not as simple as measuring force or distance; biological diversity can be understood in a multitude of ways. For example, some researchers use species richness -the total number of different species – to quantify diversity. Others may count the number of individual organisms of each species in an area. What’s important is that the community being sampled gives us basic information about occurrence, distribution and abundance of the observed species. The EDNA technique aims to avoid putting unnecessary stress on the environment and species involved. Conservationists, then, can use eDNA to survey species and habitats while doing their part to keep ecosystems intact.
Accuracy and Limitations For eDNA Sampling
Sampling builds our knowledge of species and how they are distributed which informs conservation projects and environmental policy. Environmental DNA can carry information about the life of the organism involved, like other creatures it may interact with or what foods may be part of its diet. This may not always be possible by photographing species. While it may be possible by capturing and tagging animals, these methods present other limitations.
Some species are simply difficult to detect. This may be because the species itself may be incredibly small, or its populations sizes are spread thin, making the targeted species too elusive to detect by conventional means. Sampling with eDNA can eliminate limitations associated with capturing species, photographing them or tracking. However, eDNA can not be used to determine population quality information such bodily features and sex ratios. Therefore DNA retrieved from environments must be used in conjunction with other detection techniques to some degree.