The sperm whale, as you may know, is the deepest diver of all the whales
and can get down to probably 9-10,000 feet on dives that in extreme cases
last two hours. As you say, this presents some unique challenges for an
It's not entirely clear how they do this. In terms of the physiology,
sperm whales have many times more oxygen in their muscle tissue - bound as
myoglobin - than we do. In fact, sperm whale muscle is actually black
rather than dark red because it's so heavily oxygenated. Sperm whale
tissue can also respire anaerobically for much longer than ours can.
In terms of the pressure issue, there are a couple of things going on.
Two of the big problems with human divers and baropressure is that a)
they're breathing pressurized air from tanks; and b) they can't collapse
their lungs. Thus, when they dive that air goes under increased pressure
and when they ascend too quickly it (actually the mitrogen in the air)
forms bubbles in the blood, which can be fatal (the bends). It's the same
thing as shaking up a can of soda and then taking the top off - the gas
(CO2) is pressurized by the shaking, then the sudden release of pressure
with the cap being taken off causes the gas to form bubbles. Sperm whales
get around this problem by not breathing pressurized air - they're taking
down regular air, distributed widely about the muscles and elsewhere.
Since whales (like us) are made up mostly of water in their tissues, the
pressure isnt as much a problem as you'd think for most of the tissue,
since water is essentially incompressible. But it's the body cavities -
notably the lungs - that present the problem during the pressure of a
dive. Unlike humans, in whom the lung cavity is subject to increasing
pressure during a dive and can't react to it, sperm whales can collapse
their lungs, so that there's no large air space in their body.
Those are the basics, but it's still a bit of a stretch of one's
imagination to think about an air-breathing mammal subject to over 300
atmospheres of pressure!
By the way, recent tagging work by Woods Hole Oceanographic Institution
has shown that sperm whales are upside down most of the time when they're
at the bottom of a dive; no one is entirely sure why!
Hope this helps.
-- Phillip J. Clapham, Ph.D. Large Whale Biology Program Northeast Fisheries Science Center 166 Water Street Woods Hole, MA 02543
Tel (508) 495-2316 Fax (508) 495-2066
> > > Dear Sir, > > > > I am serving on active duty in the United States Navy as a nurse, and > am currently stationed at Naval Hospital Camp Lejeune in North > Carolina. I am also currently a student at UNC-W working on a dual > degree in marine biology and family practice nurse practitioner (I > read about job openings with NOAA needing FNP's as ship's doctors > while at sea and am very interested in pursuing that career option > when I finish with the NAVY) I am > writing you as the marine biology major. One of the classes I am > taking this semester is deep sea biology. I am writing a major term > paper on the deep diving abilities of the sperm whale, and am looking > for two major areas of information: what happens to barophobic > animals under increasing pressure, and how does a sperm whale counter > these effects. I appreciate your consideration in this matter and > look forward to hearing back from you. > > > > Sincerely > > > > Robert W Whitaker II > > > > > --- Christy Whitaker > > --- firstname.lastname@example.org > > --- EarthLink: It's your Internet.
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