# posted by
Maren Wellenreuther
Hanna and I
are in northern Norway to sample populations of seaweed flies (Coelopa frigida).
As the name indicates, these flies live on seaweed that has been washed up on
the shore and form wracks. The temperature in these wrackbeds can easily be 30
degrees above the ambient temperature and it is therefore no surprise that you
can find these flies thriving year round, even in these northern latitudes. We
are interested in how the flies manage to survive in different habitats (e.g.
gradients in salinity, exposure, extremes of temperatures), and are planning to
compare populations in southern Sweden with populations in northern Norway.
Comparisons will entail genomic and transcriptomics analyses of adult and
larval life stages, and experiments testing fitness in different habitats.
We arrived
on Tuesday and have been studying the maps of the coastline to find stretches
that are exposed to ocean swell, which is needed for the accumulation of wrack.
The expansive fjords that characterize the landscape in this part of
Scandinavia make is hard to get to the outer coast, and the journey from one
side to the fjord to the other typically leads over numerous tunnels and
bridges that seem to disappear in the sky. Snow covered mountains are framing
the view wherever we go and the temperatures that we have experienced during
the days have ranged from -15 to +7. All
in all, this part of the world is full of extremes and stunning beauty.
Yesterday
we found our first population. We traveled all day to an exposed stretch of
coastline north of the town Bodo, which is only accessible with a short ferry
journey. At the very end of the fjord we found an 80 cm deep wrack, and surely
enough, seaweed flies were abundant at that site too. It had just been raining heavily
with gale force winds, so all adults were hiding among the wrack.
The flies
were cold and did not move at all, which made sampling easy, because we could
literally pick the flies up by hand and drop them into the Eppendorf’s. At the
end of the sampling the rain and wind stopped, and within minutes all the flies
came out and ‘basked’ in the light.
All the
best to Lund and happy greetings from the Lofoten!
