Nearly 90% of cetacean species are
toothed whales. Most toothed whales are small dolphins and porpoise, however
there are a few large toothed whales such as the killer whale and the mighty
sperm whale. Toothed whales are
believed to be some of the most intelligent animals on earth. Dolphins as well
as beluga and killer whales have demonstrated their intelligence while in
captivity, and sperm whales possess the largest brain of any creature alive. The
presence of teeth and one external blowhole distinguishes toothed whales from
baleen whales. Also, most toothed whales use echolocation to locate food and
"see" their environment.
(Mammals) Order: Cetacea Sub-orders:
• Odontoceti (toothed)
• Mysticeti (baleen) Families: 14 Genera: 44 Species: 82 Length: longest—blue whaleBalaenoptera
musculus is 70 feet (21 meters); shortest—Hector's beaked whaleMesoplodon hectori is 4.5 feet (1.4 meters) Weight:blue whale—63 tons (64.4 tonnes); Hector's
beaked whale—105 pounds (48 kilograms) Life span: some species are thought to live more than 100
years Gestation: 9 to 17 months, depending on species Number of young at birth: 1
Size at birth: 1/4 to 1/3 the length of the mother Age of maturity: males—4 to 35 years; females—4 to 28
years, depending on species
Throughout history, humans hunted
toothed whales for oil and food. Sperm whales were prized by commercial whalers
for the large amount of oil that could be produced from their blubber and
spermaceti organ and for ambergris (a waxy substance that forms around squid
beaks in the whales' intestines), which was used to make perfume.
are still classified as endangered because of the great numbers that were killed
by commercial whaling through the 17th to early 20th centuries.
Baleen whales are very large, have
paired blow holes, and characteristic baleen plates that they use to filter
food. Baleen whales are the largest animals on earth, yet they feed on some of
the smallest animals in the ocean. There are 12 baleen whale species divided
into 4 families: right, pygmy right, gray and rorqual whales.
Right whales were called the
"right" whales to catch by early hunters because they are large, swim
slowly, have long baleen plates, contain lots of oil, and float when killed.
Right whales do not have dorsal fins or throat grooves. The taxonomy of this
family is rather confusing, but currently there are three species of right
the Northern right whale,Southern right
whale and bowhead whale.
pygmy right is in a separate family although it shares similar characteristics
to right whales.
A Gray Whale at the Surface to Spyhop Photo taken by Dave
Gray whales have their own taxonomic
family, genus, and species. They are the most coastal of the baleen whales and
are often found within a few miles of shore. Each year gray whales migrate
between their summer feeding grounds in the Bering, Chukchi, and Beaufort Seas
to their winter breeding grounds off Baja California, Mexico. This is one of the
longest migrations by a mammal species.
Gray whales are gray in color and their
skin is encrusted with barnacles and a unique species of small crustaceans known
as "whale lice." They have 2-3 short throat grooves and instead of a
dorsal fin they have a low dorsal hump followed by 6-12 "knuckles" or
bumps. Whalers used to call gray whales "devil fish" because of their
aggressive response to being hunted.
Rorqual whales are relatively
streamlined in appearance and have pointed heads and small pointed fins. They
can be distinguished from other whales by many (25-90) deep groves along their
throats that expand when they feed. The species of rorqual whalesare:
Northern and Southern blue
Image Credits:FAO Fisheries Global Information
minke, and Eden's ("small-type") whale. Antarctic minke whales are
larger than their Northern Hemisphere counterparts, with females reaching a
maximum length of 10.7 meters (35 feet) and males reaching 9.8 meters (32 feet).
The maximum weight of adults is about ten tones (11 tons). Northern Hemisphere
minke whales reach a maximum length of 9.2 meters (30 feet).
Toothed whales have 1 to 65 teeth
depending on the species and tend to be smaller than baleen whales. Toothed
whales have a single blowhole and do not have baleen plates.
There are several families of
Odontoceti, or toothed whales, including sperm whales, pygmy sperm whales,
beaked whales, river-dolphins (3 families) belugas and narwhals, dolphins and
A Close-Up of a Sperm Whale Head and Blow Hole Photo taken
by Rocky Beach, NMML
The sperm whale is the most famous
of the Physeteridae family. It is also the largest of the toothed whales and may
dive deeper than any other cetacean. Herman Melville made the sperm whale famous
in his classic novel Moby Dick. A similar toothed whale family is the Kogiidae
family which includes the pygmy sperm whale and dwarf sperm whale which are
significantly smaller than the sperm whale but share characteristics such as the
spermaceti organ, the blunt head, and the distinctive narrow lower jaw.
Beaked whales are members of the
Ziphiidae family. The name Ziphiidae was derived from the Greek word "xiphos"
meaning sword so beaked whales are the "sword-nosed whales." Beaked
whales are the least well-known of all cetaceans. Some species have never been
seen alive and have been studied only when dead animals wash ashore. Beaked
whales may be rare or simply elusive but, generally, they live in deep water far
from land and are rarely seen.
Sowerby's beaked whale
Image Credit:FAO Fisheries Global Information System
It is believed that there are 20 living species
of beaked whales, including the North Pacific bottlenose whale, Shepard's beaked
whale, Sowerby's beaked whale, and Stejneger's beaked whale.
Whaling started in
the first few centuries A.D. by the Japanese, and between about 800 and 1000
A.D. by the Norwegians and by the Basque people living on the north coast of
France and Spain.
The Dutch, British
and Americans started in the 17th century. All of this early whaling was done
from small boats using hand-thrown harpoons. Most of the whalers hunted the slow
and docile Northern Right Whale, so named because it was the "right
whale" to hunt. The Europeans wanted the whales for their oil and for their
baleen. The Japanese ate the meat, and found uses for many other parts of the
Modern whaling began
in 1868, when the harpoon gun and explosive harpoon (which explodes inside the
whale) were invented. The harpoon guns were mounted on fast steam-driven
vessels, making it possible to catch the faster-swimming rorquals (blue, fin,
Sei, and Minke whales). The development of factory ships made it possible for
the whalers to stay at sea for long periods, increasing the number of whales
they could hunt.
Whaling has been
regulated by the International Whaling Commission (IWC) since 1946. The IWC gave
its member nations quotas on the whales they wanted to hunt, based on
negotiations and guesswork. The quotas were always too high, so the populations
declined rapidly. After the biggest whales (blues) were hunted to the point that
they were too hard to find, the whalers went on to the next largest species, the
fin whale. Then they moved on to the Sei whale, then the Minke, and humpbacks
were also taken.
The blue whale
population was estimated at 250,000 in 1920 but has been reduced by 96%, and the
fin whale population, previously estimated at 600,000, has been reduced by 92%.
Humpback and Sei whales were also hunted down to a small percentage of their
original populations. The IWC is open to non-whaling nations as well as whaling
n 1982 the IWC was
able to adopt a resolution calling for an indefinite moratorium on commercial
whaling, which became effective in 1986.
There are also some
loopholes in the IWC Moratorium. First, compliance with the moratorium is
voluntary: any IWC member country can file a protest of the moratorium, and then
need not abide by it: Norway is hunting Minke whales in the North Atlantic under
such a protest. Second, there are exceptions for "aboriginal whaling";
the American Eskimos are still allowed to hunt the bowhead whale and the gray
whale, and the Russians are allowed to take 100-200 gray whales to serve to
their northern aboriginals. Third, whaling "for scientific research"
is still allowed.
In 1994 the IWC was
successful in setting aside a huge area around Antarctica as a Southern Ocean
Sanctuary, which should protect about 90% of the world’s whales and their
major feeding areas. The proposal passed by a vote of 23-1, with Japan casting
the single opposing vote.
Norway, Japan ,
Canada, Greenland, Russia, Denmark and Iceland continue whaling to various
Japan has continued
and expanded its whaling activities in spite of intense international pressure
to abide by the moratorium and sanctuary resolutions. It has expanded its
"research program" to include permits for 50 Bryde's and ten sperm
whales in the North Pacific, along with a quota of Minke whales that was
increased from 100 to 260 for the 2006 season.
problem in protecting whale species has been illegal whaling.
So far, no species
of whale has gone extinct because of whaling, but many species have been reduced
to "commercial extinction" (too rare to be worth hunting), and many
local populations, or "stocks", have been eliminated.
Bycatches in fisheries
Direct hunting and bycatch remain the
greatest threats to the survival of these graceful aquatic mammals. Recent
analysis has shown that around 300,000 small whales, dolphins, and porpoises die
each year (about one every two minutes) as a result of becoming entangled in
fishing gear. Known as bycatch, this accidental catch is one of the greatest
threats to the survival of many cetacean populations. Many whales get caught up in large scale
high seas drift nets and over the past 25 years this has become a serious
threat. In 1993 the UN establishes a Global moratorium on large-scale driftnets
outside the 200 mile Exclusive Economic Zones. The only problem is that this
needs to monitored closely.
Vessel traffic, riverbank
development, damming and irrigation projects can seriously injure whales causing
populations to start declining.
These are the greatest threat the
survival of whales. It is the effect of industrial chemicals and pesticide
run-off that are the most important threats.
The chemicals gather in the
whales blubber while they feed heavily in the summer months. These are then
released into their milk when they migrate to the winter calving grounds, where
there is little food.
Whales depend on sound for
navigation and communication for finding food. Both traffic and industrial
activity can increase underwater noise which can reduce the whales' ability to
An increase in surface water
temperature is linked to a decline in zooplankton which will affect all species
that depend on it. Also higher levels of solar radiation caused by the reduction
in stratospheric ozone has led to declines in phytoplankton production which is
the basis of the entire food chain in the ocean.
Accidents and Disturbance.
Many Northern right whales in
North Atlantic have scars from boat propellers so we need to make sure boat
traffic is regulated and the whales are protected from harassment.
For more information on Whales,
Dolphins and Porpoise click on the logos below
Credit: The National Marine Mammal Laboratory,
FAO Fisheries Global Information System, The Illinois State Academy of Science,
American Cetacean Society, School of Biological Sciences, University of
California , The United States Navy
compiled from The British Antarctic Study, NASA, Environment Canada,
UNEP, EPA and other sources as stated and credited Researched by Charles
Welch-Updated daily This Website is a project of the The Ozone Hole Inc.
a 501(c)(3) Nonprofit Organization http://www.theozonehole.com