What do we do here...

Earlier I told you that we (team Stanford) are researching the effect of
iron and light on the growth of phytoplankton here in the Amundsen Sea. To
put it simply, there are two groups of phytoplankton down here: Phaeocystis
(a rather smelly form of phytoplankton) and diatoms (these have silicate
skeletons and have very cool shapes when you look at them under the
microscope). The Phaeocystis is really good at sucking CO2 out of the water
(and thus the atmosphere), whereas diatoms are the preferred food for the
krill that is eaten by whales and penguins. That’s why we are trying to
figure what makes Phaeocystis grow and out compete diatoms and vice versa.
We have studied both Phaeocystis and diatoms in the lab and from our
experiments it seems that Phaeocystis does not like very bright sunshine.
That damages their photosystems. They are, however, very efficient at low
light conditions and also at low iron concentrations. Thus, our hypothesis
was that under high light and iron conditions diatoms would out compete
Phaeocystis, and under low light and iron conditions Phaeocystis would win.

To test this in the field, we are taking water from and incubate in bottles
in incubators that are screened with different types of window screening
(from home depot). We added iron to half of them and check after a couple
of days which phytoplankton will start to grow. We have now done four
experiments and…. Phaeocystis is outcompeting the diatoms in every
single one of them. Hmmmm, time for a new hypothesis…


In the meantime we are gathering data about photosynthesis at different
light and iron levels. Other people are measuring how the phytoplankton
relate to the bacteria and other parameters. So we’re getting lot’s of
exciting data to base new hypothesis on!