Combining Efforts to Document and Understand Changes in Antarctic Conditions

It is no secret that the world's oceans are changing at a dramatic rate.  The WAP (West Antarctic Peninsula) isone region that is experiencing the harshest changes due to an increase in warming.  Sea-ice availability is rapidly declining.  Shifts in seasonal temperatures are evident.  Lastly, the food-webs are being altered in a way that only certain species are benefiting and others are struggling to cope.

The whole warming in the WAP (see figure below) is due to probable shifts in wind capacities in the Southern Ocean, pushing that warm water from the ACDW (Antarctic Circumpolar Deep Water) upwards into the ACC (Antarctic Circumpolar Current).  This deep current upwells all of that warm, saline water onto Antarctica's shelf.  Hence, we see a decline in sea-ice coverage and a change in ecosystem structure.  As the sea-ice presence changes, so does the food-web. 

The shift in warmer temperatures have shifted the size in phytoplankton from larger to smaller.  This poses a problem for grazers because most are more efficient at preying on larger cells, the most notable being krill.  Krill play an extremely important role in the Antarctic food web because they are the transfers of energy from lower levels to higher levels.  If krill struggle to survive, that means the larger organisms will struggle to survive and the smaller phytoplankton cells will continue to thrive.  This can be seen with the Adelie penguins.  They thrive in areas where they can be around a constant food supply so they can reproduce and forage.  Other species of penguins that are not depend on sea-ice (Chinstraps and Gentoos) are showing an increase in population.

It is inevitable at this point that the WAP is changing and we need to learn how and why the physical effects of ocean change is effecting the ecosystem.  New technological advances have made it possible to do this.  We have gliders, animal tracking sensors, sea-floor cables, remote sensing instruments, and other technologies.  Data collection and effort will have to be a collaborative effort within the oceanographic community if we want to understand the changes occurring in the WAP.

-Colin

Tags: , , ,