This is an interesting bit of news from Environmental News Service about how the ocean works!
Tiny Plants Stir Ocean, Affect Climate
TALLAHASSEE, Florida, October 16, 2006 (ENS) - The microscopic plants that form the vast foundation of the marine food chain generate five times the annual total power consumption of the human world, according to a new study by a team of oceanographers.
The study estimates the yearly amount of chemical power stored by phytoplankton in the form of new organic matter is roughly 63 terawatts - one terawatt equals a trillion watts. In 2001, humans collectively consumed 13.5 terawatts.
The study also found that the marine biosphere - the chain of sea life anchored by phytoplankton - invests around one percent, or 1 terawatt, of its chemical power fortune in mechanical energy. This energy is manifested in the swimming motions of hungry ocean swimmers ranging from whales and fish to shrimp and krill. Those swimming motions mix the water much as cream is stirred into coffee by swiping a spoon through it, the researchers explained, and the sum of all that phytoplankton-fueled stirring may equal climate control.
"By interpreting existing data in a different way, we have predicted theoretically that the amount of mixing caused by ocean swimmers is comparable to the deep ocean mixing caused by the wind blowing on the ocean surface and the effects of the tides," said lead author William Dewar of Florida State University.
Biosphere mixing appears to provide about one third the power required to bring the deep, cold waters of the world ocean to the surface, which in turn completes the ocean's conveyor belt circulation critical to the global climate system, DeWar explained.
Findings from the study will appear in the forthcoming issue of the "Journal of Marine Research."
Scientists for some time have known that the highly sensitive plants act as reliable signals of environmental changes at or near the ocean surface through sudden declines or rapid growth.
Furthermore, they have suspected that phytoplankton affect as well as reflect climate change when large, sustained plant populations gulp carbon dioxide from the atmosphere during grand-scale photosynthesis.
But along with the new calculations that point to the marine biosphere's bigger-than-expected role in ocean mixing and climate control, Dewar and his colleagues also suggest that human and environmental decimation of whale and big fish populations may have had a measurable impact on the total biomixing occurring in the world's oceans.
