The ocean plays an important role in regulating Earth's climate, primarily because the tiny plants that float near the surface, known as phytoplankton, consume the greenhouse gas carbon dioxide through photosynthesis.  Because carbon dioxide released from human activities is causing the Earth to warm, it is important to know how much carbon dioxide phytoplankton consume and what other factors impact this.   Nitrogen, the same stuff found in plant fertilizers, is necessary for phytoplankton to conduct photosynthesis, but nitrogen is scarce in the ocean.  One type of phytoplankton, called Trichodesmium, has a way of extracting its own nitrogen from air, which means that they play a special role in the ocean.  Trichodesmium lives in little colonies, or blobs about the size of the letter "o" in the text you are reading, which contain dozens of Trichodesmium along with hundreds of other microbes.  We found that all of these other microbes chemically communicate with each other by secreting ("oozing") molecules that tell their neighboring microbes who they are and what they need. In addition, we learned that one of the things they communicate about is delivering to Trichodesmium the other nutrients, such as phosphorus and iron, it needs to be able to make its own nitrogen.  This is a really significant finding because we now know that communication is important in determining how much nitrogen gets delivered to phytoplankton in the ocean, but before we thought that nutrients floating out to the ocean in dust were the main important factor.  It is amazing to think that communications between microbes ultimately affect how much carbon dioxide gets consumed by phytoplankton.  The next step is to figure out if this communication in the ocean is likely to increase or decrease in the future if Earth's climate continues to change.

Last Modified: 01/10/2017
Modified by: Benjamin Van Mooy