Science: Discovering rare marine organisms using eDNA tools

On June 16, 2018, the days of discovering and studying rare and endangered marine animals through the search for oceans around the world are not yet over. However, an emerging tool for analyzing seawater samples may help scientists learn more about rare marine organisms than ever before. According to Dr. Ellen Pikitch of the Institute of Ocean and Atmospheric Sciences (SoMAS) at Stony Brook University in the United States, this 21st-century tool is the analysis of  environmental DNA (eDNA).  She  published a point of view paper in the June 15, 2018 Science journal titled "A tool for finding rare marine species."

In the ocean, eDNA can be obtained from seawater containing shedding skin cells, scales, secretions, and other substances from marine life. This method has proven to reliably and non-invasively detect rare, elusive and difficult-to-research species such as threatened whales, sharks and dolphins.

In this paper, Pikitch explains how eDNA can be used to detect the presence of species and to quantitatively determine the abundance of species. She compared this approach with other technologies used to study rare marine species, many of which are less sensitive, require high-intensity labor, and involve capturing animals and destroying habitats.

Pikitch said, "eDNA is superior to traditional methods of studying marine species in many ways. Given its advantages, eDNA may soon become the method of choice for detecting rare and elusive marine species."

In addition, the eDNA method is rapidly improving and becoming more cost-effective.

She concludes, "As a complement to mainstream methods and based on its own merits, eDNA is expected to accelerate our understanding of marine life."