Tuesday, October 30, 2012
Antarctica Oct 27
Chandra, our FSTP person who makes sure that we don't fall into the ice, picked us up at 9:00 in the most luxurious vehicle here - a bright orange Hagglund. The purpose for this trip was not only to have the experience of seeing the Weddell seal colony but also to record their sounds above the water.
We took off across the Sea Ice to Big Razorback Island to visit Jay Rotella, the Weddell seal expert, who was tagging the Weddell seal pups that were just born. Through tagging they can keep track of individual seals and their habits and migration.
The colony was comprised of mother seals and their newborn pups.
Weddell seals are the most southerly mammal on Earth. This is the time of year when the mother seals birth their pups. The mother seals are between 880-1360lbs and have stored enough fat to nourish their pups until they are ready to be on their own. The pups are between 55 and 60 pounds at birth. After the Mom's instructions, the pups are ready to swim at about 2 weeks old.
We watched a pup learn how to make a hole in the ice with his jaw. It started out as a little turbulence and ended up in a perfect hole with the pup’s nose poking out.
Weddell seals can go without oxygen for 80 minutes and can dive down to 2480 feet deep. Anaerobic metabolism causes an increased build-up of lactic acid in the muscles. This lactic acid does not enter the blood stream until the seal surfaces. Weddell seals have a large amount of red blood cells/ unit of blood and an increased amount of oxygen carrying capability. They can reduce their heart rate and constrict their capillaries, which allow the red blood cells to be more efficient.
By controlling the efficiency of red bloods cells, the Weddell seal can spend long periods of time under the sea ice. They do all of their mating, fighting, and eating under water and only come up for a rest in the sun or to birth their pups.
All the Pups are nursing now so that they will be strong enough to be on their own in 2 months. It was quite a treat to witness all of this and to hear the grunts and squeals of the Weddell seals.
Posted by Diane Tuft