Award: OCE-1031143

Phytoplankton are microscopic creatures that live in the sunlit surface waters of the ocean. Like plants on land, phytoplankton take up carbon dioxide through photosynthesis. Since carbon dioxide is a greenhouse gas, phytoplankton play a critical role in regulating Earth's climate. Our project focused phytoplankton in the Sargasso Sea, which is region where the nutrients that phytoplankton need are very scarce. One important nutrient, phosphorous, is bound in molecules called phospholipids, which are made by phytoplankton and almost all other forms of life to make the walls of cells. We found the phytoplankton in the Sargasso Sea save phosphorus by making some, but not all, of their cells walls out of non-phosphorus lipids. We hypothesized that when phytoplankton die, their phospholipids rapidly decompose, yielding phosphorus, while non-phosphorus lipid decompose slowly. We went on an oceanographic research ship to the Sargasso Sea and measured the rates of lipid degradation. Our data showed that phospholipids do indeed degrade quickly, in many cases faster than non-phosphorus lipids. This means that phospholipid degradation could be an important source of phosphorus for phytoplankton in the Sargasso Sea. This is important because we now know more about how phytoplankton are able to take up carbon dioxide in regions of the ocean where phosphorus is scarce. These regions are probably going to expand as the earth continues to warm up, so our study will help to predict the future role that phytoplankton will play in regulating Earths climate. Last Modified: 12/23/2013 Submitted by: Benjamin Van Mooy