Whales, dolphins, and porpoises all
belong to the same taxonomic order called cetaceans. Cetaceans are comprised of
about 80 kinds of whales, dolphins, and porpoises. The word cetacean is derived
from the Latin "cetus" (a large sea animal) and the Greek "ketos"
(sea monster).
They are mammals which means
they are warm-blooded, they have at least a few hairs on their bodies, and they
nourish their young with milk. Cetaceans spend their whole lives in water and
some live in family groups called "pods. "There are about 80 species of
whales, dolphins, and porpoises populate the world's oceans. To study these
cetaceans we categorize the species into two main groups: baleen whales (or,
mysticetes) and toothed whales (or, odontocetes).
Comparative Size of Whales
Species
Length
(m)
Length
(ft)
Species
Length
(m)
Length
(ft)
Blue
whale
21-27
69-88½
Fin
whale
18-22
59-72¼
Bowhead
whale
14-18
46-59
Northern/Southern
Right whale
11-18
36-59
Sperm
whale
11-18
36-59
Sei
whale
12-16
39½-52½
Humpback
whale
11.5-15
37¾-49¼
Bryde's
whale
11.5-14.5
37¾-47½
Gray
whale
12-14
39½-46
Baird's
Beaked whale
10.7-12.8
35-42
Minke
whale
7-10
23-33
Killer
whale
5.5-9.8
18-32¼
Arnoux's
Beaked whale
7.8-9.7
25½-31¾
Northern
Bottlenose whale
7-9
23-29½
Longman's
Beaked whale
7-7.5
23-24½
Southern
Bottlenose whale
6-7.5
19¾-24½
Shepherd's
Beaked whale
6-7
19¾-23
Cuvier's
Beaked whale
5.5-7
18-23
Pygmy
Right whale
5.5-6.5
18-21½
Short-finned
Pilot whale
3.6-6.5
12-21½
Strap-toothed
whale
5-6.2
16½-20¼
Blainsville's
Beaked whale
4.5-6
14¾-19¾
False
Killer whale
4.3-6
14-19¾
Long-finned
Pilot whale
3.8-6
12½-19¾
Gray's
Beaked whale
4.5-5.6
14¾-18½
Hubb's
Beaked whale
5-5.3
16½-17½
Stejneger's
Beaked whale
5-5.3
16½-17½
True's
Beaked whale
4.9-5.3
16-17½
Ginkgo-toothed
Beaked whale
4.7-5.2
15½-17
Gervais'
beaked whale
4.5-5.2
14¾-17
Narwhal
3.8-5
12½-16½
Beluga
3-5
9¾-16½
Sowersby's
Beaked whale
4-5
13¼-16½
Andrew's
Beaked whale
4-4.7
13¼-15½
Hector's
Beaked whale
4-4.5
13¼-14¾
Lesser
Beaked whale
3.4-3.7
11¼-12¼
Bottlenose
dolphin
1.9-3.9
6¼-12¾
Risso's
dolphin
2.6-3.8
8½-12½
Pygmy
Sperm whale
2.7-3.4
9-11¼
Northern
Right Whale dolphin
2-3
6½-9¾
Southern
Right Whale dolphin
1.8-2.9
6-9½
White-beaked
dolphin
2.5-2.8
8¼-9¼
Indo-Pacific
Hump-backed dolphin
2-2.8
6½-9¼
Melon-Headed
whale
2.1-2.7
7-9
Dwarf
Sperm whale
2.1-2.7
7-9
Pygmy
Killer whale
2.1-2.6
7-8½
Irrawaddy
dolphin
2.1-2.6
7-8½
Rough-toothed
dolphin
2.1-2.6
7-8½
Fraser's
dolphin
2-2.6
6½-8½
Atlantic
Hump-backed dolphin
2-2.5
6½-8¼
Atlantic
White-sided dolphin
1.9-2.5
6¼-8¼
Striped
dolphin
1.8-2.5
6-8¼
Boto
1.8-2.5
6-8¼
Indu/Ganges
River dolphins
1.5-2.5
5-8¼
Baiji
1.4-2.5
4¾-8¼
Pacific
White-sided dolphin
1.7-2.4
5¾-8
Pantropical
Spotted dolphin
1.7-2.4
5¾-8
Common
dolphin
1.7-2.4
5¾-8
Atlantic
Spotted dolphin
1.7-2.3
5¾-7½
Peale's
dolphin
2-2.2
6½-7¼
Dall's
porpoise
1.7-2.2
5¾-7¼
Spectacled
porpoise
1.3-2.2
4¼-7¼
Dusky
dolphin
1.6-2.1
5¼-7
Long-snouted
Spinner dolphin
13-2.1
4¼-7
Short-snouted
Spinner dolphin
1.7-2
5¼-6½
Burmeister's
Porpoise
1.4-2
4¾-6½
Harbor
porpoise
1.4-1.9
4¾-6¼
Finless
porpoise
1.2-1.9
4-6¼
Hourglass
dolphin
1.6-1.8
5¼-6
Tucuxi
1.3-1.8
4¼-6
Heaviside's
dolphin
1.6-1.7
5¼-5¾
Commerson's
dolphin
1.3-1.7
4¼-5¾
Franciscana
1.3-1.7
4¼-5¾
Black
dolphin
1.2-1.7
4-5¾
Hector's
dolphin
1.2-1.5
4-5
Vaquita
1.2-1.5
4-5
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.
Class: Mammalia
(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
Sperm whale
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.
Sperm whales
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
whales:
Northern right
whale
the Northern right whale,Southern right
whale and bowhead whale.
The
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
Withrow, NMML
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:
humpback whale
fin whale
Bryde's whale
Northern and Southern blue
whale
northern
minke
Image Credits:FAO Fisheries Global Information
System
antarctic
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
porpoises.
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.
Threats Facing
Whales
Whaling
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
whale.
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
nations.
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
degrees.
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.
Another major
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.
Habitat Degradation
Vessel traffic, riverbank
development, damming and irrigation projects can seriously injure whales causing
populations to start declining.
Chemical
Pollution
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.
Noise
Pollution
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
communicate.
Global
Climate change
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.
"SAVE THE WHALES
AGAIN!"
Actress and 'Save the Whales Again!'
campaign spokeswoman Hayden Panettiere and House Natural Resources Committee
Chairman Rep. Nick Rahall, D-W.Va. pose for photos following their news
conference on Capitol Hill in Washington, Tuesday, Jan. 29, 2008
Japanese
Whalers Kill Baby Minke Whale (Very Disturbing)-Click
Here
A
CAST OF "REAL LIFE HEROES" OFFICIALLY LAUNCHES THE
"SAVE THE WHALES AGAIN!" CAMPAIGN-Click
Here
13
December 2006 – The Baiji Yangtze Dolphin is with all probability extinct-Click
here
Navy Granted Authority to Use
Sonar in Training off California-Click Here
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
Data
compiled from The British Antarctic Study, NASA, Environment Canada,
UNEP, EPA and
other sources as stated and credited Researched by Charles
Welch-Updated dailyThis
Website is a project of the The Ozone Hole Inc. a 501(c)(3) Nonprofit
Organization