DNA detectives able to ‘count’ thousands of fish using as little as a glass of water

A mere glass full of water from Monterey Bay Aquarium’s 1.2 million-gallon Open Sea tank, among the 10 largest aquariums in the world, is all scientists really needed to identify the Pacific Bluefin tuna, dolphinfish and most of the other 13,000 fish swimming there. Researchers also for the first time used DNA from water samples to discern which of the species were most plentiful in the tank.

Being able to determine the relative abundance of fish species in a body of water is the next step in possibly using modern DNA identification techniques to census fish in the open ocean, according to Ryan Kelly, University of Washington assistant professor of marine and environmental affairs, and lead author of a paper in the Jan. 15 issue of PLOS ONE.