Subject: Various questions

Phil Clapham (phillip.clapham@noaa.gov)
Fri, 08 Jan 1999 12:58:31 -0500

Hi Erin:

Here are answers to your questions:

> How long can a whale stay under water?
> Does it matter which type of whale it is?

Depends on the kind of whale, as you thought.  The record diver is
probably the sperm whale, which has been timed as diving for two hours. 
Sperm whales also hold the dive depth record, since they've been tracked
to more than 7,000 feet and there's good circumstantial evidemce that
they can go deeper than that.  Beaked whales are also long, deep
divers.  Baleen whales (like the humpback) aren't as accomplished, but
can remain submerged for half an hour or more in extreme cases; the more
usual dive time (especially when feeding) is around five minutes. 
Baleen whales also don't dive as deeply as sperm whales - while they can
probably get to 100 feet, for the most part they forage in a few hundred
feet of water, because that's where their prey (fish, krill or small
plankton, depending on the whale species) is located.

> What is the longest  ammount of time that a radio tag has been kept track of/ 
followed?
Dr Bruce Mate of Oregon State University has had a satellite tag on a
humpback whale for around six months now, I believe, and that's probably
the record.  Attaching a tag to a whale isn't easy; unlike bears or
wolves (etc) they don't have necks, so the tag has to be implanted into
the whale's blubber, and tags tend to work their way out over time.

> Do you have to have a licence to take a whale captive?
Yep.  All cetaceans are protected in the U.S. under the Marine Mammal
Protection Act (passed by Congress in 1972), and any capture of a whale
by a U.S. institution requires a permit.  It is only ever given for
research or public display purposes.

> Why do whales beach them selfes?
Well, we don't know in all cases, and there are probably different
reasons.  Single whales that come up do so because they are very sick. 
Mass strandings (where whole groups strand) are a different matter.  The
most likely cause, in most (maybe not all) cases is a combination of bad
weather, rapidly falling tide, shallow water at low tide and a species
that isn't used to coastal areas (such as pilot whales, which frequently
get caught like this).  There are other theories too, but it's pretty
clear to those of us on Cape Cod (where a lot of mass strandings happen)
that most of them can be explained this way.

> Thank you for answering my questions, I really apreciate it.
You're very welcome!

Good luck,

Phil Clapham

Phillip J. Clapham, Ph.D.
Northeast Fisheries Science Center
166 Water Street
Woods Hole, MA 02543

tel (508) 495-2316
fax (508) 495-2066
Internet: phillip.clapham@noaa.gov