Amazing! DNA technology gives us a new way to do a fish census.
A glass full of water is all fish detectives needed to identify approximately 13,000 fish living in the larger body of water from which the sample was taken, report researchers.
The secret is in DNA that water-dwelling organisms regularly release into their environment.
“It might be unpleasant to think about when going for a swim in the ocean, but the water is a soup of cells shed by what lives there,” says study lead author Ryan Kelly of the University of Washington.
He explains that fish shed cells from their skin. They and other organisms also release unneeded things, such as damaged tissues and bodily waste.
The researchers next hope to try the technique out in a natural setting: San Francisco Bay. It could be used in any number of locations, however. The goal is to have an easier, more accurate marine life census tool.
The technique was tested at the Monterey Bay Aquarium’s 450,000 litre Open Sea tank, where they know what lives in there and can judge the tests accuracy. The result was successful in that it identified the eight species of bony fishes in the tank correctly determined the greatest amount of biomass in the tank. It also picked up DNA from fish that was added to the tank as food.