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however, hampered by the fact that the dark period of the Arctic winter is hardly studied
at all, and the few investigations to date reveal a much more active system than anticipated
(e.g. Berge
et al
.,
2009
).
Summer conditions are predicted to change much more drastically than winter condi-
tions, creating a much wider range of conditions in which organisms must be able to sur-
vive; thus likely altering the relative abundance of species as well as their distributions. It
is expected that the advection of warmer water zooplankton species, which enter the Arctic
Ocean with the Atlantic water through the European Arctic Corridor or with Bering shelf
water through the Bering Strait (Hunt
et al
.,
2013
) (e.g. the calanoid copepods
Calanus fin-
marchicus
and
C. marshallae
), will penetrate deeper into the Arctic Ocean in decades to
come.
Combining what we know about today's structure and function of the Arctic marine
ecosystem at different spatial and temporal scales and using predictive physical models,
we derive the following hypotheses concerning the biological response to future physical
change:
·
The most rapid adaptive and evolutionary responses in the Arctic marine ecosys-
tem will be at the microbial and micro-phytoplankton level, where change will be
non-uniform and non-linear over time, with disproportionally increased respiration
and competition for nutrients and carbon between photo- and heterotrophs (Do-
main 4).
·
A decrease in size and/or concentration of primary producers along with shifts in
the bloom regime will yield a less efficient grazing pelagic food web and less ex-
port to the benthos, leaving less energy to support species at the highest trophic
levels and thus affecting predators including humans (Domain 4 to Domain 3).
·
Changes to some biological hot spots (e.g. increased upwelling along the shelf
break or loss of intensive productivity along the ice edge) will result in shifts in
migratory patterns and abundance of species aggregations such as bird colonies or
