Tuesday, December 12, 2006

Polarstern meets whales

By: Julian Gutt

Whales in the ice

Although one of the smallest baleen whales, the Antarctic Minke Whale is also one of the most wide ranging, occurring from the equator to Antarctic waters. It is known that the Antarctic ice edge is an important feeding area. However, it is still unclear how and if these cetaceans use the large ice-covered area between the Antarctic continent and the ice edge. Global climate change affects the amount and the type of ice on the polar seas. If the Antarctic sea ice is a vital habitat for the Minke whale, a change in its composition could have a serious impact on this animal.

To study how the Minke whale behaves in the ice we, the “marine mammal team” (Meike Scheidat and Linn Lehnert), use the Polarstern and its two helicopters. During aerial surveys we can cover a large area in a short time – independent of how much ice is on the water. On one of our first flights we had a sighting of a Minke whale in waters covered with ice. The animal was swimming in a small ice-free area a hundred meters in diameter. For a few minutes the helicopter stayed still and allowed us to observe the whale swimming in and out from under the ice. The clear waters gave us a view of its body under the water including the tell tale light grey flippers. The blow, which in this species is normally too small to be seen, was clearly visible due to the humidity in the breath condensing in the cold Antarctic air.

Five more sightings from our observation platform on the boat showed how well adapted to the life in the ice this species is. On one occasion we saw the pointed head of the Minke break through fresh sea ice close to the Polarstern to take a breath.

During the next ten days we will cross the Weddell Sea and hope to have many more opportunities to see the Antarctic Minke Whale from boat and from helicopter. Once we can determine how important the sea ice is to this whale, we might be able to better predict how a possible change in the ice coverage will influence their life.

 

Photographs from left to right: David Fischer, Meike Scheidat

 

Mehr zu "Census of Antarctic Marine Life"....

 

Wir freuen uns über Kommentare und Anregungen zum Bericht im Forum!


<- Back to: Archiv_ANTXXIII/8