The pair's goal was to speed up water flow without resorting to expensive and short-lived battery-powered pumps. Instead, the ecologists relied on simple physics that require a volume of water to flow faster when it moves through a narrowed space.
Based on prototypes developed in a giant flume in the basement of the BioMed research building at Brown, they built channels about 7 feet long and about 18 inches high. They lined the walls with plates where organisms could latch on and grow. The test channels narrowed to about half their width in the middle, taking on a bow tie shape. The control channels remained the same width throughout. The control and test channels were placed about 3 to 6 feet below the lowest tide in each of two sites in Maine and Alaskan coastal waters.
In every case they found that the number of different species on the plates in the test channels was much higher than on the plates in the control channels. The greater diversity was no flash in the pan, either. The pattern was visible from early stages and persisted for more than a year of study. Witman also surveyed natural areas in Palau, and Palardy and Witman did the same in Alaska, finding similar effects in areas with faster flow.
Witman said his hope is that the work will not just explain greater biodiversity but will help stem the tide of its loss.
"There's a global biodiversity crisis where we're losing species," he said. "Ecology is very much concerned with sustaining natural processes."
|Contact: David Orenstein|