Subject: Whales and seals leave scienti (fwd)

Mike Williamson (pita@www1.wheelock.edu)
Wed, 17 Sep 1997 12:39:23 -0400 (EDT)

---------- Forwarded message ----------
Date: Wed, 17 Sep 1997 10:01:55 +0100
From: "Mathieson, Scot" <SMathieson@sepa.org.uk>
To: 'Mike Williamson' <pita@www1.wheelock.edu>
Subject: RE: Whales and seals leave scienti (fwd)


No surprise in this headline !  Interesting report.

Hope you like it

Scot

>Whales and seals leave scientists in the dark
>
>  By John von Radowitz, Science Correspondent, PA News
>   Astonishing secrets of seals and whales were revealed today that are
>baffling
>scientists investigating them with hi-tech tracking devices.
>   Both the Elephant Seal of the Southern Oceans and the Beluga whale of the
>the
>Arctic are capable of extraordinary diving feats which scientists are
>struggling
>to understand.
>   Experts are also baffled by the uncanny way the seals appear to
>communicate,
>using methods one can only guess at.
>   The mysterious lives of the creatures are being revealed for the first
>time
>by
>scientists using sophisticated electronic tags that allow the animals to be
>tracked over long distances and at great depths.
>   Some of the most surprising findings were described today at the British
>Association's annual science festival taking place at Leeds University.
>   They include the ability of Elephant Seals to spend up to two hours
>underwater, diving to depths of two kilometres, after taking a three minute
>gulp
>of air. When making a dive their heart rate falls from 120 beats per minute
>to
>just one.
>   Under normal circumstances this should not be possible. Professor Mike
>Fedak,
>from the Sea Mammal Research Unit at St Andrew's University, Scotland, said:
>"We can estimate the oxygen stores they have on board and the rate at which
>they are used. Effectively they are staying down longer than they should be
>able
>to stay down."
>   Professor Fedak said it was suspected that the seals conserved energy by
>selectively shutting off organs and muscles they did not need.
>   Beluga whales perform equally remarkable exploits. They have been tracked
>making dives of thousands of feet, apparently in order to spot air holes in
>ice
>canopies that extend for hundreds of miles.
>   The whales travel enormous distances under polar ice 30ft thick despite
>only
>being able to hold their breath for 20 minutes.
>   Dr Tony Martin, also from St Andrew's, said the record dive for a Beluga
>wasset by one animal which descended an incredible 1,000 metres - more than
>3,000ft
>- before coming straight back up again.
>   Why the white whales, famed in sailors' folklore, made these deep dives
>which
>appeared to be nothing to do with seeking food remained a mystery.
>   Dr Martin said: "I think what they must be doing is using these deep dives
>to
>search the underside of the ice for the next breathing space.
>   "It's a bit like a pilot who's engine has cut out, but in reverse. You
>stay
>up in the air to get the best search radius for a landing site. In the same
>way
>the Belugas dive down to search the widest area of ice.
>   "They are very sensitive acoustically and I think they are listening for
>the
>tell-tale slop of water on the edge of an ice hole."
>   Scientists have also found a male-only restaurant for Belugas, a feeding
>site
>550 metres deep only visited by males. They think this is because only males
>have the strength to stay down long enough at that depth for a meal.
>   Elephant seals have astounded scientists by the ability of individuals
>dispersed over vast tracts of the Southern Ocean to meet at specific feeding
>and
>breeding sites.
>   The creatures have even been tracked following the precise path another
>individual took a year earlier.
>   Professor Fedak said: "These sort of coincidences suggest to us that there
>is
>some sort of information being passed around, but we have no idea what it
>might
>be."
>
>