Big Picture In Small Places
9:43 am
Thu January 16, 2014

Researchers Detect and 'Count' Fish From Just A Glass Of Water

It's not something we often think about, but as we go about daily life, we're constantly shedding little flakes of skin. So are animals and fish. This fact now makes it possible to estimate which species are most plentiful in a lake or bay.

University of Washington professor Ryan Kelly is jazzed.

"This is about the coolest project I have been involved in,” Kelly said.

That's because Kelly's research team could detect and count with just a glass of seawater the species of fish swimming around nearby.

Kelly says "every living thing is" constantly sloughing off DNA into the environment. Now improved sensitivity of instruments along with the falling cost of DNA sequencing make it feasible to identify many or all of the fragments in a scoop of water.

"What we are doing is building a tool so that you can go out into the world and much more quickly find out about the living resources that are living nearby,” Kelly said.

Kelly says this has the potential to make surveys for endangered species easier. The greatest value could come from simplifying fisheries counts and management. First, though, the researchers have to further validate the technique in open water where you have to contend with dynamic currents and mixing.

The details are newly published in the journal PLOS One. The David and Lucile Packard Foundation funded this research.