Subject: Info: Float or Sink? (fwd)

Michael Williamson (pita@whale.simmons.edu)
Tue, 28 May 1996 13:20:14 -0400 (EDT) 

Why would some whales float and others sink?
Why would a whale refloat after it sank?
What processes or cycles are involved?

---------- Forwarded message ----------
Date: Tue, 28 May 1996 08:36:13 +0100
From: Anders.Jelmert@imr.no
To: Multiple recipients of list MARMAM <MARMAM@UVVM.BITNET>
Subject: Re Float or Sink?

    At Marmam, May 23rd., Emma Jones wrote

    > To Marmam readers,

    > I am interested in the fate of cetaceans when they die at sea; do they
    > sink, float, sink and then refloat etc. I would be interested in hearing
    > from anyone who has information on the subject or anyone who may
    > have seen floating carcasses themselves at sea.

    > Thanks in advance,

    > Emma Jones

    Dear Emma Jones.

    I am still a bit confused on what time-scale you have in mind here.
    Apparently, it was earlier assumed that most whale carcasses find their
    way to the abyssal sea floor. (Krogh 1934; Bruun, 1957). However, based

    on the frequency of posts about strandings at MARMAM, I think this could be

    modified somewhat. Perhaps this is exactly what you intend to do?

    There are some recent reports on invertebrate comunities thriving on whale
    skeletons in the deep ocean basins.
    You will find an interesting story and numerous relevant refs. in:
    Bennett et al.(1994)

    Another approach to this area was given by Butman, et al. (1995.).
    These autors suggested that whaling could have altered the deep-sea
    biodiversity significantly, by diminishing an important source of
    carbon to the sea-floor.

    That particular paper prompted myself and a collegue to made a comment;
    Jelmert and Oppen-Berntsen, (1996) on the same issue, as we found
    such a hypothesis highly implausible. We regard the biomass
    contribution from pre-whaling cetacean stocks to be insignificant,
    (two to three orders of magnitude less, by conservative calculation)

    compared to the contributions from rest of the marine biota.


    Litterature:

    Bennett, B.A., Smith, C.R., Glaser, B. and Maybaum, H.L. 1994.
    Faunal community structure of a chemoautotrophic assemblage on
    whale bones in the deep northeast Pacific Ocean.

    Bruun, A.P. 1957. Deep sea and abyssal depth. Pages 641-672 in
    J.W. Hedgepeth, editor. Treatise on marine ecology and paleo-
    ecology, vol I. Ecology memoir, 67. Geological Society of America,
    Washington D.C.

    Butman, C.A., Carlton, J.T. and Palumbi, S.R., 1995.
    Whaling Effects on Deep-sea Biodiversity.
    Conservation Biology vol.9 No.2:462-464.

    Jelmert and Oppen-Berntsen,1996. Whaling and Deep Sea
    Biodiversity. Conservation Biology vol 10 No.2:1-2

    Krogh, A. 1934. Conditions of life at great depths in the ocean.
    Ecological Monographs 4:430-439


    Hope this could be of some help.

    Greetings from wet and cold western Norway.

    Anders Jelmert
    Institute of Marine Research,
    N-5392 Storebo, NORWAY

    anders.jelmert@imr.no