Sea ice melting and glacier runoff
strongly influence the coastal zone of
the western Antarctic Peninsula, leading
to very shallow mixed layers and locally
high primary production. These conditions
support sufficient krill stocks to
feed both currently low and historically
large populations of penguins and other
predators. Primary production is low in
comparison to most other coastal sites
dominated by macrophytes, but similar
to pelagic production in temperate
and subtropical sites. Like other coastal
regions around the world, the WAP
ecosystem is exhibiting complex and
increasingly rapid changes due to the
combined effects of climate change
(partially anthropogenic), fisheries overharvesting,
and pollution. The Antarctic
coastal system, once dominated by large
organisms at all trophic levels, appears
to be transitioning toward a microbedominated
system. A paradox of the
Southern Ocean is that it is simultaneously
one of the most comprehensively
protected of global marine systems,
owing to the Antarctic Treaty, and one of
the most impacted, as a consequence of
rapid climate change, human exploitation,
and the novel poleward transport of
anthropogenic compounds.