Antarctic Fur Seal tracking

The tracking devices.

The track from a Fur Seal (in red) recorded back in December.  She ventured over 50 miles out into the ocean to feed before returning to her pup.

The Zoological field assistant is very busy this time of year and today I was lucky enough to go over to Maiviken to help Alastair in his work selecting suitable female fur seals and fitting electronic tracking devices.  The tracking is important in helping BAS scientists understand the feeding habits of the Fur Seals.  This has a direct correlation with the work Katie, the fisheries biologist is undertaking into the Krill population.  Krill ("Euphosia Superba" - a Crustation similar to a Prawn) is an important cornerstone in the Ecology of the Southern Ocean in that it largely forms the basis of the food chain.  Fur Seals feed on Krill (which is odd, as they are equipped with such large teeth!)  Females with Pups are chosen for tagging as they will return to the same spot after feeding.  In some harems (groups of female fur seals) it is sometimes difficult to see which pup belongs to which female as the seals are lively and move around quite a bit.  It is ideal to see a pup suckling, as this confirms motherhood.  The selected seal is segregated and three devices are positioned on the seal's back.  One is a GPS tracking device, which, instead of deriving a fix for itself like a normal GPS - it will merely take a "snap shot" of the sky when the seal is ashore or on the surface of the sea, and a computer will then work out the relevant positions when the tracker is recovered at the end of the study.  The second unit is a device to measure Depth, Temperature and Light intensity.  This information will help build a detailed picture of where the seal has been, and how deep she has had to dive for food.   The third is a VHF radio transmitter.  It transmits a signal so that on the seals return, Alastair can pinpoint the tagged seal out of hundreds of seals.  He uses a tracking antenna to track the beeping signal.  The units are carefully glued to the seals fur.  This method ensures no harm is done to the seal, and all trace is lost when she malts her fur in February.
Unfortunately, after a hike over to Maiviken, the weather thwarted efforts as showers of rain and sleet had made the seals wet, and the adhesive does not stick, so no tags were attempted.....

A dive record from the same seal.  She dived to a maximum depth of 77 meters.  She slows her heart rate to decrease her bodies use of oxygen to allow her to dive so extensively.