Fish forensics yields amazing results

explores

TThe oceans are teeming with life, but the sheer volume of water on our blue planet makes finding this life a little frustrating sometimes. Traditional methods of locating marine organisms – cameras, direct observation, net fishing, etc. – are not comprehensive, and monitoring remote areas poses greater logistical difficulties. This means that even the most comprehensive surveys of ocean life will have some gaps.

Now, those gaps are being filled in thanks to some very small clues.

To get a more complete picture of life in our oceans, a team of researchers turned to environmental DNA, or eDNA. These traces of DNA are left by marine organisms during their normal lives, from fluids, dissolved cells, and the like. The eDNA is then collected in seawater samples, filtered and matched against databases to determine which animals shed it. In aquatic environments, eDNA tends to degrade relatively quickly, making it a good indicator that the species it belongs to was present in the area. Finally, the team’s eDNA survey included more than 900 water samples from diverse depths ranging from the poles to the tropics, according to their research. He studies Published in PLoS Biology.

Read more: “The challenge of deep-sea classification“

Nautilus members enjoy an ad-free experience. Log in or join now.

The team, from the University of Montpellier in France and the National Center for Scientific Research, found that the geographic ranges of more than 93% of the species discovered had previously been underestimated, meaning that these species actually live in a larger area than previously thought. In addition, some species have been discovered to tolerate amazing environments. For example, the team found DNA from alligator icefish — a species thought to live only in the frigid waters of Antarctica — as far north as Patagonia in waters about 18 degrees Fahrenheit warmer.

These findings have important implications for ocean conservation for a very simple reason: it is impossible to fully understand the threats to marine life without first fully understanding the scope of marine life. With this study, the web of our understanding surrounding ocean life has become a little tighter.