Where are we at?

Over the last few days we have
cast several plankton tows
(Picture 1) off the back deck to
collect protists and crustaceans.
For the bigger crustaceans we
use a 200 micron mesh screen
net and we catch the larger
sized algae and protozoa with a
20 micron mesh net. Protists
range from < 1 micron (small
flagellates) to several hundred
microns (foraminifera). If you
take the thickness of a dime and
slice it 1000 times you will get 1
micron. Both nets are lowered
to approximately 5 m depth
with a small weight attached.
Today we left the nets to drift
for 30 minutes. We usually
attach a flowmeter to calculate
the volume of water that we
screen and counting the number
of organisms that we catch
allows us to calculate the
abundance of the plankton. The
last few days it was rather cool
outside with wind chills around
minus 35 degree Celsius - hence
the gear (Picture 2). The
creatures that we catch are
brought to our 0 degree cold
room where they are inspected
under the microscopes. We
recovered several crustaceans
(copepods (Picture 3), shrimp
and amphipods), sarcodines
(foraminifera, radiolaria and
acantharia), jelly fish, comb
jellies, snails (Picture 4) and
many more. Some of the
smaller protists are picked and
transferred into media for
culture collections. If they
successfully grow in culture we
will be able to study their
physiology and get DNA
sequence information to
investigate how many species
are present in these waters.

November 4, 2003