By Jeff McQuaid

Why Antarctica, and why now?

Diatoms from last year's expedition (Dawn Moran, WHOI)

So why are you going to Antarctica, and why are you going now? A very logical question... basically we are traveling to Antarctica to study microscopic marine plants known as phytoplankton. These organisms range in size from bacteria to diatoms to colonial algae, but all phytoplankton have two things in common: they are small enough to float in the water without sinking, and like all plants, they produce their own food using sunlight and carbon dioxide. They are so small that a cup of seawater may contain a million of them, and because they are at the base of the marine food chain, everything from shrimp to fish to whales depends on their existence as a food source. Phytoplankton are some of the most numerous creatures on earth, and ongoing climate research suggests that these microscopic plants will be the primary sink for absorbing and sequestering excess carbon dioxide greenhouse gasses.

If plankton are everywhere, then why go to Antarctica to study them? Well, it probably comes as no surprise that Antarctic plankton are some of the least studied of all the earth's organisms, as simply getting to Antarctica is no small feat. But in addition to being one of the least studied environments, polar environments such as Antarctica are among the most endangered: ongoing climate change is affecting the polar regions faster than any other place on the planet, so there is some urgency to catalog what is there and how it is changing, and therefore establish a baseline of fundamental scientific knowledge.

To do this we will be using a number of tools developed for studying organisms which are too small to see. We will go out onto the sea ice and collect samples of water, and in addition to identifying the plankton using a microscope, we will try to identify them by reading and understanding their unique DNA signatures. We will be sequencing both the genes in the plankton, and also the genetic messages, or transcripts, that the plankton are producing. The transcripts are particularly interesting, as capturing them is like intercepting coded messages on what the plankton were doing at the time they were collected. At the same time, other members of our team will be analyzing the protein components of the plankton, and looking to see if the stories told between the DNA sequences and protein identifications match. In the end we hope to gather enough information to assemble a portrait of phytoplankton diversity and function in the Ross Sea.

To wind down this posting, here's a montage of some of the diatoms we found on last year's expedition. They really are beautiful!