Subject: Re: whale abundances, depletion, distribution

Dr. Cathy Schaeff (schaeff@american.edu)
Wed, 01 Oct 1997 16:36:54 +0000

Sue Shirley wrote:
> Here are a few more questions from the rest of my fifth grade science s=
tudents.
>=20
> >From Kaitlinn, Natalie and Maddy:
> Have you ever studied two Blue whales that are related?  How many Blue =
whales
> are left in the world? Could you send us a picture of a Blue whale?

There were 228,000 Blue whales prior to commercial hunting; there are
now about 12,000. Between 1904 and
       1978, whalers took more than 200,000 animals, most from the
southern hemisphere, many illegally. The Blue Whale now protected from
commerical but illegal hunting probably still occurs.

> >From Bobby and Justin:
> What is the world's population of Sperm whales?

Current estimate is that there are about 1,900,000 Sperm whales. Feeding
areas include deeper waters around the Aleutian Islands in North
Pacific, off New Zealand, Peru and Chile in the South Pacific,
Newfoundland Grand Banks and the continental slope west of the British
Isles, north towards Iceland in the North Atlantic, east coast of South
America from Argentina to the Faulkland Islands and
       around Tristan da Cunha in the South Atlantic. Mating and calving
areas include waters off New Guinea and around Hawaii in the North
Pacific, deep waters off East Australia, Galapagos and Ecuador in the
South Pacific, around the Bahamas, the Azores and Madeira in the North
Atlantic, off Brazil, Angola and Southwest Africa in the South Atlantic,
off Western Australia, around
       Madagascar, and west and north of Seychelles to the coasts of
India, Sri Lanka and the Arabian peninsula in the Indian Ocean.



> >From Liz and Torie:
> How long has the Right whale been endangered?=20


They have been hunted for centuraries and were depleted so much that
they were considered commerically extinct TWICE. 	Termed the =93right=94
whale to kill by hunters because they inhabited coastal waters and
floated when dead, the North Atlantic right whale (Eubalaena glacialis)
population experienced a prolonged and severe reduction.  Commercial
whaling of this species began in the 16th century and continued into the
early 1900s. As well, because most whaling routes originated in the
northern hemisphere, and hence included the North Atlantic coastal-water
habitats, the North Atlantic animals continued to be taken by hunters
even after their numbers were too limited to make them the sole focus of
whaling expeditions.  As a result, the western North Atlantic right
whale population probably experienced a severe, long-term reduction and
may have been reduced to as few as 60 animals.  Right whales were
protected internationally in the 1930s.  However, despite over 60 years
of protection, this population has shown few signs of recovery and is
currently estimated to be growing at a rate of only 2.5% per year ,
which is only one third that of South Atlantic right whales. =20


What is the difference between a
> Northern Right whale and a Southern Right whale?
>=20

Right whales live in the oceans of both hemispheres (Northern right
whales, E. glacialis, and Southern right whales, E. australis).=20
Although very similar in appearance and breeding biology, Northern and
Southern right whales are considered to be different species due to the
six month difference in their reproductive cycles and the geographic
distance between them. 	Migration in both species occurs seasonally,
with the right whales moving towards the higher latitudes in the summer
to feed, and then back to the lower latitudes and the warmer waters in
the winter to calve. =20

> >From Sam and Toby:
> How long has the Blue whale been endangered?
>=20
There were 228,000 Blue whales prior to commercial hunting; there are
now about 12,000. Between 1904 and
       1978, whalers took more than 200,000 animals, most from the
southern hemisphere, many illegally. The Blue Whale now protected from
commerical but illegal hunting probably still occurs.


> >From Rob, Eric, and Adam:
> How many Right whales are there in the world?
>=20

There are about 350 in the northern hemisphere (300-320 in the North
Atlantic, one or two in other oceans); there are about 10,0000 in the
southern hemisphere.


> Thank you for your time,
> Sue Shirley
> Dedham Country Day School
> Dedham, MA

--=20
Dr. Cathy Schaeff
Biology Department=20
American University
4400 Mass. Ave. N.W.=20
Washington D.C. 20016-8007
(202) 885-2175 (phone)
(202) 885-2182 (fax)
schaeff@american.edu (email)