(Written by S. Cullum, C-IMAGE, Teacher at Sea, 8/10/14, 9:49 am)


In layman’s terms, phytoplankton are microscopic floating plants.  While there are several different kinds of phytoplankton, the most common ones are the groups called diatoms and dinoflagellates.  These organisms are extremely beneficial to the environment in many ways.  To the marine ecosystem, they represent food.  As the phytoplankton process the sun’s energy into chemical energy (photosynthesis), they are rapidly eaten by larger zooplankton (microscopic floating animals), which in turn are eaten by small fish and invertebrates.  As they food chain continues, a large number of organisms are supported through the energy produced initially by the phytoplankton.


Unbeknownst to many, humans are extremely dependent upon phytoplankton.  Why?  Let’s go back to biology class where you hopefully learned about the cycles of photosynthesis and cellular respiration.  Photosynthesis, usually performed by chlorophyll containing plants, represents the conversion of the sun’s energy into a storable form of energy known as ATP.  (By the way, those chlorophyll containing plants are also found on your dinner plate next to the meat and macaroni and cheese!)  Cellular respiration, performed by most life forms, is the complimentary chemical cycle that converts that ATP into form of energy that your body can use – glucose. So, what does that have to do with humans besides the much needed ATP?


Do me a favor…take a deep breath in…and now exhale.  (Repeat as necessary!)  The oxygen you breathe in day after day is a byproduct of photosynthesis.  Plants, including the enormously abundant phytoplankton in the oceans, provide the essential compound needed for you, as well as most life forms on earth, to survive.  In fact, most scientists agree that these single-celled organisms were the major force in converting earth’s early toxic atmosphere into the life-supporting blanket it is today.


So, when you wake up each morning, do me a favor, please give a big shout-out to the diatoms and dinoflagellates of the world!  Without them, you and I would be breathing a bit heavier each day.