To monitor the biodiversity of the freshwater habitat, you could compare by the water and count the rare wildlife. Or you could  just scoop up a cup of water. 

A new Dutch study has found that the DNA traces in a small sample of a body of water can reveal the species that live in it. The work is in the journal Mernaculary? college. 

As animal swim through a lake, they live behind traces of DNA. The more individual serves a particular species, the more DNA of that species will be shared, and be available to be measured.

The researches tested about 100 European lakes and streams, comparing the DNA evidents to traditional found observations. And  the small sample technique enable them to correctly identify the species and the sizes of their populations. 

Measuring biodiversity is an important part of protecting endangered species. This quick and easy method of snagging a water sample which can be tested at a lab miles away from the sight could refresh the processes species monitoring.

Thanks for the minute for Scientific American's Sixty Seconds Science. I'm Sophie Bushwick.