Dispatches...
Stories from the CFL at the top of the
world...
Viruses; tiny
microbes, big players in the Arctic
Ecosystem...
July, 08 - 2008
Hello,
my name is Claire Evans and I am a post doc
working at the Royal Netherlands Institute
for Sea Research based on the island of
Texel in the Netherlands. My job is to
investigate the role of viruses, the
smallest of all microbes, in the marine
ecosystems of both the Arctic and
Antarctic. With good fortune I find myself
onboard ‘Amundsen’ for two legs of the CFL
study which sees me the join the ship in
late April and stay until the latter part
of July. During this time things changed
significantly in the Amundsen Gulf with the
melting and flushing of the ice revealing a
more traditional watery seascape. The
chemical and physical changes which occur
in the water column as a result of the ice
retreat stimulated the growth of
phytoplankton cells, tiny unicellular
plants, in the surface waters. In turn the
organisms which eat the phytoplankton will
increase in number in response to the
development of these ‘blooms’ and the
levels of bacteria will increase as they
can feed on matter released by these
organisms. My task here is to investigate
whether viruses play a role in this
microbial Arctic food web by infecting and
killing the phytoplankton and bacteria.
This is important because when viruses
infect a cell they cause it to burst open
by a process we call lysis, which releases
all the chemicals and matter within that
cell to the water column. This influences
the biology of the sea by reducing the
amount of these cells available to be eaten
by larger animals. In this way viruses
could decrease the amount of food available
for higher organisms such as Polar Bears!
Also viral lysis influences the chemistry
of the oceans by causing the release of the
cells contents to the seawater which can
change the levels of nutrients and other
important substances in the ocean. It is
important to study these processes as the
different environments of the Earth such as
the oceans and atmosphere are all linked in
terms of their chemistry and biology. If we
can better understand processes such as
viral lysis in the Arctic and how
significant they are it allows us to fit
another important piece into the jigsaw
that is the mysterious workings of our
blue-green planet!
