Many science fiction stories tell about explorers arriving in a new world. The explorers then use some kind of high-tech device to test for breathable air or signs of life. But here on Earth, science fiction is becoming reality through a new sampling technology called environmental DNA, or eDNA for short. Scientists can use it to identify rare species or estimate fish populations with just a little air or water.
Environmental DNA can be used in two ways. One is to identify the creatures that live in a certain place. The other is to confirm the presence or lack of a specific creature.
Caren Goldberg is one of the first biologists to take the technology from the testing stage to actually using it. She sees eDNA as a way to get answers more efficiently and with less destruction compared to traditional survey techniques. Until recently, scientists depended on snorkeling ( 潜水), netting or using an electric current to temporarily catch fish.
This newer way to identify what lives in the environment is becoming popular around the world. Animal experts in Vietnam are using the eDNA to find the last, wild Yangtze giant softshell turtles. One researcher on the Caribbean island of Trinidad is using the sampling technology to find endangered golden treefrogs. In Madagascar, it is being used to identify amphibian(两栖动物)diseases.
Ms Goldberg has used eDNA testing to confirm the local extinction (灭绝) of a leopard frog in the American state of Idaho. She has also been asked to document the spread of the New Zealand mudsnail in the state of Washington. The creature has been found in lakes and other waterways across the state.
Scientists working with the technology say they do not expect robots to replace field biologists anytime soon. But the old-fashioned field work could soon be more targeted.
