Subject: Various questions on whales

Jen Philips (jphilips@soest.hawaii.edu)
Tue, 9 Dec 1997 17:04:14 -1000 (HST)

On Mon, 8 Dec 1997, Angie Steiner wrote:

> Form: Memo
> Text: (18 lines follow)
> My name is Angie Steiner, and I am updating a documentary for National 
> Geographic, and I wonder if you could confirm or refute  the following 
> information:
> 
> -Are the Southern Ocean and Indian Ocean Sanctuaries a haven for 80% of the 
> world's whales?
> 
> -Do scientists believe that whales first evolved in Antarctic waters?
> 
> -the documentary states that in warmer water, the infant Humpback whale 
> needs far less food to maintain it's body heat, so most of it's mother's 
> milk can be turned into blubber. Is that accurate?
> 
> - The script also states that Orca are an "indicator" species. That if their 
> numbers decrease radically, it could indicate serious pollution problems in 
> the seas. Is that an accurate statement?
> 
> Thank you so much for your help.
> Use Proportion

Angie - here are some answers to your questions, representing the
information as accurate as I know it to be.  If further research is
necessary, I might be able to provide you with some resource citations. 

1.  Re: Southern and Indian ocean havens - there are marine sanctuaries
set up in these oceans, and it is true that many if not 80% of the world's
species of whales spend at least some of their time in these oceans.  The
Antarctic Ocean is probably the last pristine waters in the world, and
throughout the year there are enourmous blooms of zooplankton and fish
which support large numbers of whales.  However, the term haven may not
apply here because it implies that the whales are safe from harm and
dangers, especially from humans, in these waters.  These waters may be
sanctuaries, but enforcement of regulations in the international climate
is not easy.  Whaling continues to be conducted by a couple countries, and
the southern ocean is the target of some of that whaling activity.  Japan,
for example, continues to hunt the Minke whale, doing most of their
whaling I believe in the southern ocean.  So, though printine and hugely
productive, I would not say these oceans are havens.  

2. Re: evolution of whales - Actually, scietists believe the first whales
evolved about 50 million years ago in a circumgloal sea called the Tethys
Sea.  Part of the sea became partly enclosed, shallow, and tropical, and
it is thought that it was here that the earliest cetaceans began entering
the sea.  Fossils of this first cetacean, the Archeocete, have been found
in Pakistan, India, and North Africa.  Later, they began evolving and
moving all over the world, and essentially the whales that we see today
evolved in all the worlds oceans, not only the Antarctic.  

3.  Re:  Humpback calves and warmer water - it is most likely true that
the warmer waters of the breeding and calving areas provide for better
growing conditions for new calves.  New calves are able to nurse on their
mothers highly fat rich milk, growing both in size and in blubber layer.  

4.  Re:  The orca as an indicator species - this is a tougher one, mainly
since the concept of an 'indicator species' is a strictly define term in
ecology.  Basically, an indicator species, often a microorganism or a
plant, serves as a measure of the environmental conditions that exist
in a given locale. In order to perform this role, the species must have a
few qualities:  it must have a known set of physical or chemical
requirements necessary for absolute survival.  This limit of extreme
factors, such as temperature, that a populations can tolerate and still
survive must be known.  They must have a relatively quick turnover in
population numbers, so that effects of conditions in the environment are
seen quickly enough.  I personally have never heard of the orca discussed
as an indicator species anywhere in the world.  It also does not seem that
they should be able to serve in this role.  Orca's occur globally, in
every ocean.  Some have small home ranges, others have large ranges.  They
live for up to 80 years and do not reproduce until they are probably 10 or
15.  Also, the limits of extreme conditions that they can tolerate are not
known, and so effects to their population can not clearly indicate
anything other than possible 'problems' to their habitat or prey
population.  This is an interesting question, and I would love to know
from where this information first arose.  It is not necessarily inaccurate
to say that the orca is highly visible, closely entwined with their
environment and therefore problems we see with their population indicates
serious habit destructions, etc.  But this is indeed true of all species
in the world.  True 'indicator species' serve to the ecologist a much more
measured and defined role as fast information about certain defined
factors in an environment.    


Well, I hope this has served to help you in updating the documetary.
Please respond again if more information is desired.  Thanks for writing
to whalenet!

Aloha -

Jennifer D. Philips				jphilips@soest.hawaii.edu

Marine Mammal Research Program - HIMB		(808) 236-4001
University of Hawaii, Manoa          
Honolulu, HI  96822	      "First, there were some amoebas. Deviant
			       amoebas adapted better to the environment,
			       thus becoming monkeys..."       - S.Adams
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