Scientists have tracked fish off New York by following the traces of DNA left in the water, a technique that could help gauge life in rivers, lakes and oceans around the world, a study showed on Wednesday.
Fish leave bits of slimy skin, scales and excretions as they swim around — clues that let scientists detect 42 species of fish, including herrings, basses and eels in water drawn from the Hudson and East Rivers off Manhattan, it said.
"Rather than get a big boat and a big net ... we just tied a bucket onto a rope and threw it into the river," said lead author Mark Stoeckle, from New York's Rockefeller University.