defecation in whales

From: Merel Dalebout (merel_dalebout@hotmail.com)
Date: Mon Jan 31 2000 - 15:44:04 EST


>This might seem like a strange question, but I was wondering about >whale
>fecal matter. I was wondering if you could tell me what it's >consistancy
>is, and how much of it is expelled in an average day, by different whales.
>Thank you very much.
> Patrick

Dear Patrick,

Thank you for your question, which I dont think is a strange one at all.
Elimination of wastes from the body, and maintaining equilibrium of the
bodys salinity levels, especially in an aquatic environment, is an
important matter for any organism.

The only way in which cetaceans can rid their bodies of the surplus salt
they ingest as part of their diet is to produce extremely large amounts of
urine, with a resulting loss of water, although the size of the kidneys in
many species appears to belie this necessity. For cetaceans living in fresh
water, such as river dolphins, or for killer whales that feed primarily on
other marine mammals, this is less of a problem, as less salt is ingested
when they feed. The greatest problem would be felt by baleen whales feeding
on krill, and toothed whales feeding on squid.

>From Yazawa we learn, via Slijper (1979), that the urine of a fin whales
(Balaenoptera physalus) is clear and pale, has an acid reaction and contains
the normal mammalian proportion of urea.

Cetacean faeces appear as a brownish-yellow cloud (ie a fecal plume) in the
water, and are released in a burst. Sperm whales are often observed to
defecate just before they commence a deep feeding dive.

Apart from that, how often different species have to go, and how much they
release in, I am not sure. Hope this helps as a start though. You could try
asking the next "ASK a scientist" on whalenet (my session ended on Sunday)
to see if they could give you some more information.

Cheerio

Merel

************************
Merel Dalebout
PhD student
School of Biological Sciences
Thomas Building, L2
University of Auckland.
Private Bag 92019
Auckland
New Zealand
Ph: 64-9-373-7599 x4588
Fax: 64-9-373-7417
E-mail: "Merel_Dalebout@hotmail.com"
      or "m.dalebout@auckland.ac.nz"

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