What are Plankton ?
Plankton are organisms (animals, plants or bacteria) which are suspended in water. Plankton are generally small in size (a few microns) but can be much larger (several centimeters). Animal plankton is called zooplankton and plant plankton is called phytoplankton.
Zooplankton and phytoplankton are at the bottom of the oceanic food chain. They are the main food source for blue whales as well as certain shellfish.
Phytoplankton are made up of micro-algae and photosynthetic bacteria. Through the process of photosynthesis, phytoplankton absorb carbon dioxide (a greenhouse gas that contributes to global warming) and emits oxygen ( a gas necessary for animal survival). It therefore functions as a regulator of our climate. Contrary to popular belief, phytoplankton (rather than trees), are the primary “lungs of the Earth” as phytoplankton are the principle consumer of carbon dioxide and generate half of the planet's oxygen production.
Why study Plankton ?
As a climatic regulator, phytoplankton play a key role in climate change. However, these organisms remain relatively understudied, even more so in remote areas such as Antarctica.
Additionally, as a result of global warming, phytoplankton flowering cycles are now changing. Indeed, with warmer temperatures comes an acceleration in the melting of the ice caps, which in turn causes the ocean water to receive more sunlight. This directly alters the phytoplankton communities of the Antarctic region. As this phenomenon is a relatively new finding, it is important to follow its evolution over time. Monitoring of the planktonic communities in Antarctica will make it possible to establish more representative models of planktonic populations, and thus better models of climate change.
Moreover, as phytoplankton is a food source for zooplankton, its modification directly alters the properties of zooplankton. And, as all plankton (both animal and vegetable), are the basis of the oceanic food chain, this creates evolutionary shifts for all local fauna.
What are we going to study there?
We will take samples along the way in partnership with Plankton Planet. These samples will be prepared, analysed under a microscope and then stored on the boat in order to be sent to the CNRS - upon our return to America - for analysis and storage.
To carry out a sampling we will have to follow a very precise procedure in which we were trained in Brest. This procedure is explained in a simplified way in the graph on the left.
Our samples will then be sent to the CNRS laboratories based in Roscoff (North Coast of Brittany) where they will be processed. The samples will be coupled with geographical, meteorological and marine current data corresponding to the time and place of collection. The resulting data will be used to complete the classifications of phytoplankton and zooplankton communities. These data will also allow monitoring of planktonic population trends in the Antarctic Peninsula region.