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Shifting Sands Shuffle Cells

May 28, 2012

Does sand moving on the beach carry bacteria with it? To find out, WHOI scientists Rebecca Gast, Britt Raubenheimer, and Steve Elgar cored three sections of a beach at Duck, N.C., every other day. During the five-day experiment, wind, waves, and tides reshaped the beach, adding sand at some times and removing sand at other times. Gast analyzed samples from various depths within each core for the presence of DNA from bacteria. Most samples contained bacterial DNA (black dots), indicating that natural reshaping of a beach can redistribute microbes in the sand, including the indicator bacteria that lead to beach closures.(Illustration by Jack Cook, Woods Hole Oceanographic Institution)