Today I filtered seawater from a variety of depths in the upper ocean (from the surface down to 120 meters) to collect marine plankton cells that live throughout the sunlit portion of the ocean. I am interested in microbial activities in the surface ocean because this is where sunlight and atmospheric carbon dioxide are captured and fixed by photosynthetic microbes, or phytoplankton, to create a vast pool of organic matter that fuels the ocean food web. The chemical makeup of marine organic matter is inherently complex, a product of the diversity of the hundreds of thousands of different planktonic organisms that make up seawater communities. To determine which of these compounds are most prevalent and potentially important components of the microbial food web, I have collected ocean plankton cells via filtration to return to the laboratory for chemical analysis. There, I will extract cellular (or particulate) organic matter and detect the hundreds of different organic molecules that were produced by the plankton cells. By looking at plankton from several depths throughout the sunlit ocean, I will be able to see which types of organic molecules are produced by the different plankton living throughout the upper water column.

Posted by Bryn