Subject: Whales and seals leave scienti (fwd)

Mike Williamson (pita@www1.wheelock.edu)
Sun, 14 Sep 1997 20:34:20 -0400 (EDT)

---------- Forwarded message ----------
Date: Sat, 13 Sep 97 14:15:00 GMT 
From: r.mallon1@genie.com
To: marmam@uvvm.uvic.ca, pita@whale.simmons.edu
Subject: Whales and seals leave scienti

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."