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| The Invisible Forest: Microbes in the Sea |
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SPEAKER:
Sallie (Penny) Chisholm
Professor of Civil and Environmental Engineering and Biology;
Lee and Geraldine Martin Professor of Environmental Studies
Director, MIT Earth System Initiative
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ABOUT THE LECTURE:
After listening to Penny Chisholm, you’ll view pond scum or aquarium slime in a different light. In fact, Chisholm aims to instill a sense of reverence and concern for the organisms behind this phenomenon, which turn out to be blue-green algae. They’re part of a family of microbes called phytoplanktons that are essential to the earth’s health.
Chisholm sketches the history of phytoplanktons, which first emerged on earth 3.5 billion years ago, and created the oxygen in our atmosphere that made possible all other plant and animal life. “They can live perfectly well without us,” says Chisholm, “but we can’t live without them.” Energized by sunlight, phytoplankton are the ultimate recyclers. Chisholm’s research focus, Prochlorococcus, discovered in 1985, plays a supremely important role in climate control. The smallest and most abundant photosynthetic cell on the planet, it takes carbon from the atmosphere and deposits it safely to the ocean floor.
We must stop viewing all microbes as bad guys, Chisholm says, and instead, start to worry about the collective health of the organisms that regulate the world’s metabolism. Those hard at work clearing our air of global warming gases may not fare so well as the earth heats up. When ocean temperatures rise, Chisholm says, waters get more stratified, and this may make photosynthesis more difficult for the microbes. There are proposed attempts to manipulate or work around phytoplanktons – such as ocean fertilization or deep-sea injection of CO2 – but Chisholm is deeply skeptical. We may end up sucking oxygen out of the water and creating dead zones in the ocean “that release methane, nitrous oxide and other wonderful greenhouse gases that molecule for molecule, prove more powerful than CO2 in absorbing solar energy,” she warns.
Science has only just begun to study the world’s microorganisms. Just .1% of all microbes have been cultured, and who knows what other kinds of unique and essential properties we’ll find when we start looking, says Chisholm. It’s time we begin “to build the knowledge necessary to predict, regulate and sustain these vital functions of earth systems for future generations,” she says.
Download this video at Apple's iTunesU site
ABOUT THE SPEAKER:
In addition to her other appointments, Penny Chisholm currently serves as co-director of Terrascope, an MIT learning community for freshmen. She is also a visiting scientist at the Woods Hole Oceanographic Institution. From 1988-1995, she served as the MIT Director of the MIT/Woods Hole Joint Program in Oceanography.
Chisholm received the 2005 Huntsman Award for Excellence in Marine Science, and is a Gordon and Betty Moore Foundation Investigator in Marine Science. She has published papers in PNAS and Nature. She received her Ph.D. in Biology in 1974 from S.U.N.Y. Albany.
Chisholm's Biology website
NOTES ON THE VIDEO (Time Index):
Video length is 1:00:35.
Beryl Rosenthal, Director of Exhibitions and Public Programs at the MIT Museum, introduces the event, and describes the protocol for audience participation. She then introduces Penny Chisholm.
At 3:45, Chisholm begins.
At 32:22, Rosenthal organizes the audience to formulate questions for Chisholm.
At 32:53, Rosenthal reads the questions.
Areas Chisholm discusses include:
the “dance” of viruses with microbes in ocean water;
the microbial contribution to carbon dioxide;
whether her research should serve as a source of optimism;
the impact of ocean warming on microbes;
how to educate the public;
the impact of antibacterial products in everyday life;
how long the process of carbon sequestration takes;
the impact of El Nino on microbial growth;
changes she’s seen due to global warming;
the use of microbes as sources of energy;
what microorganisms remain undiscovered that might also play important roles.
The information on this page was accurate as of the day the video was added to MIT World. This video was added to MIT World on 2007-02-07.
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