By analyzing the DNA floating about in the ocean, researchers may be able to get a better idea of what's lurking beneath the waves, Scientific American says.
Creatures living in the ocean continuously shed skin, scales, or hair as well as metabolic and other waste containing cells into the water. These environmental particles may then be trapped for analysis and comparison to a database like GenBank to see who's living in that region of the ocean.
In freshwater, Sciam's Bill Streever notes that such an approach has been applied to track invasive species and to monitor the effects of environmental hazards like chemical spills and adds that it has recently been shown to work as well as conventional methods to determine diversity in a marine environment.
John Bickham of Battelle Memorial Institute notes, though, that more work needs to be done as many of the hits he and his colleagues get can't be identified, possibly because they represent previously unknown species. He suggests that a large-scale systematics project should tackle the deep sea and other inadequately characterized regions of the world.