What if trains, planes and automobiles all were powered simply by the air through which they move? What if their exhaust and by-products helped the environment?
Such an energy-efficient, self-propelling mechanism already exists in nature.
The salp, a small, barrel-shaped organism that resembles a streamlined jellyfish, gets everything it needs from ocean waters to feed and propel itself.
Scientists believe its waste material may help remove carbon dioxide (CO2) from the upper ocean and the atmosphere.
Now researchers at the Woods Hole Oceanographic Institution (WHOI) and MIT have found that the half-inch to 5-inch-long creatures are even more efficient than had been believed.
"This innovative research is providing an understanding of how a key organism in marine food webs affects important biogeochemical processes," said David Garrison, director of the National Science Foundation (NSF)'s biological oceanography program, which funded the research.
Reporting this week in the journal Proceedings of the National Academy of Sciences (PNAS), the scientists have found that mid-ocean-dwelling salps are capable of capturing and eating extremely small organisms as well as larger ones, rendering them even hardier--and perhaps more plentiful--than had been believed.
"We had long thought that salps were about the most efficient filter-feeders in the ocean," said Larry Madin, WHOI Director of Research and one of the paper's authors.
"But these results extend their impact down to the smallest available size fraction, showing they consume particles spanning four orders of magnitude in size. This is like eating everything from a mouse to a horse."
Salps capture food particles, mostly phytoplankton, with an internal mucus filter net. Until now, it was thought that included only particles larger than the 1.5-micron-wide holes in the mesh; smaller particles would slip through.
|Contact: Cheryl Dybas|
National Science Foundation