Patrick Robinson at the Eastern Weddell Sea, Antarctica--We tagged three additional Weddell seals yesterday to bring our total up to nine and the seals are already sending us interesting data.  The seals have already collected more than four times the number of CTD profiles collected by the ship!  Here is a sample of the various data sent back to us from the tags:

Diving behavior:  the tags collect depth measurements during the dives.  This allows us to determine how deep the animals are going and how long they stay underwater.  Some seals are diving all the way to the bottom (up to 700 meters) while others are feeding off of the continental shelf and diving to more shallow depths (200 meters).

A sample of the diving behavior data from one Weddell seal. Several of these dives are longer than 20-minutes!

Movement:  satellites orbiting the earth track the animals by receiving signals transmitted from the tag.  We receive several positions per day and this allows us to make a track of where the seals have been and how fast they are moving.  Right now, most of the seals are remaining very close to their favorite ice floe, but some are already 100 kilometers away.

ARGOS satellite tracking data from the Weddell seals.  Each color is a different animal.

Oceanography:  sensors on the tag record temperature and salinity, two properties of ocean water that allow oceanographers to classify water masses.  Individual profiles are interesting, but when hundreds of profiles are compiled it is possible to learn how immense water masses are formed move around Antarctica.

Temperature and salinity data collected by a Weddell seal two years ago during a pilot study led by Keith Nicholls.  (Nicholls et al (2007). Wintertime ocean conditions over the southern Weddell Sea continental shelf, Antarctica. Geophysical Research Letters 35)