What is eDNA and Why is it Important?

Tanya Dapkey, the Macroinvertebrates Section Lead of the Patrick Center for Environmental Research, stands on the edges of the Delaware River. Trees rustle in the breeze, the water laps on mossy rocks. Holding a small clear vial of water, her collected sample, Dapkey is using a novel scientific technique aimed at detecting particles of living organisms — eDNA.  

So, what exactly is eDNA and why is it important?  

First, DNA is a fairly common acronym. It stands for deoxyribonucleic acid, and is an organic compound that holds the genetic instructions that organize the development and functioning of all living things. These compounds are responsible for transmitting or expressing the unique and specific characteristics of each living being.

Environmental DNA analysis is a key tool that enables critical insights into aquatic biodiversity. Samples collected of lake, stream, estuary and ocean water all contain these tiny compound biomolecules from the organisms that live there such as plants, fishes, mollusks, amphibians — simply floating around in the currents. The identities of those organisms can be revealed by genetic sequencing of the water sample, instead of organisms themselves.  

According to the National Aquatic Environmental DNA Strategy, eDNA is one technological advancement that offers the potential for faster and more effective assessments to understand aquatic life. Scientists can uncover the story of an entire ecosystem by studying biomolecules — the DNA, RNA and proteins — that ultimately reveal the biological foundations of healthy ecosystems, food production and water safety for drinking and swimming.  

Without catching a single live fish or frog or cutting down a single plant or flower, scientists like Dapkey can use eDNA to track and quantify the ecological community of a specific area — what lives there, their numbers, their history, their invasive species — painting the true picture of local ecology in real time. And what makes eDNA so promising is it is as simple as collecting water and running an analysis on it — a technique that is non-invasive, accessible, reliable and scalable.  

Unlike traditional techniques, eDNA usage in fieldwork can more quickly and accurately advance our understanding of the composition of an entire environment, helping Academy scientists to better inform policy and approaches to conservation management. 

But the results of their data and findings are only as good as the references to which they are compared. This is why museum collections, like the Academy’s, are so vitally important.  

“Without taxonomists standing behind all this eDNA analysis data — naming, comparing and describing what we have found using this novel tool — the data doesn’t mean anything,” says Dapkey. 

Samples from the Delaware River study sites will be stored in the Academy’s collections for perpetuity, building up an accurate library of information about the region’s major waterways, watersheds and natural lands throughout time. Scientists will be able to paint an accurate picture of many different species’ population changes or when and where certain invasive species have entered into the ecosystem.  

Now and in the future, researchers or scientists from across the nation can access all this data to better understand the regional impacts of climate change, sustainability and environmental conservation needs.  

You can support the Academy’s research efforts to understand the natural world and inspire everyone to care for it by becoming a member or donating to our scientific collections.

Tú también puedes apoyar los proyectos de investigación de la Academia, y así ayudar a entender y proteger la riqueza natural convirtiéndote en miembro o haciendo una donación a nuestras colecciones científicas.