The whale

THE PEOPLE'S DEMOCRATIC REPUBLIC OF ALGERIA

SALAH ABDELLI MIDDLE SCHOOL

RAS-EL-OUED

THE TITLE OF THE PROJECT: THE WHALE
***اضغط على هذا الرابط***

DONE BY: H. MOHAMED

TEACHER: BOUKEBECHE

ACADEMIC YEAR: 2008/2009

Whales are marine mammals. They are the ***اضغط على هذا الرابط*** largest animals ever to have lived.

Where whales live
Whales live in the Atlantic, the Indian and the Antarctic oceans.

What whales look like
Whales look like giant dolphins. The body is ***اضغط على هذا الرابط*** bursiform, resembling the streamlined form of a ***اضغط على هذا الرابط*** fish. The forelimbs, also called flippers, are paddle-shaped. The end of the tail holds the fluke, or tail fins, which provide propulsion by vertical movement. Although whales generally do not possess hind limbs, some whales (such as ***اضغط على هذا الرابط*** sperm whales and ***اضغط على هذا الرابط*** baleen whales) sometimes have rudimentary hind limbs; some even with feet and digits. Most species of whale bear a fin on their backs known as a ***اضغط على هذا الرابط*** dorsal fin. Beneath the ***اضغط على هذا الرابط*** skin lies a layer.

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Whales are divided into two suborders:

The ***اضغط على هذا الرابط*** baleen whales are characterized by ***اضغط على هذا الرابط*** baleen, a sieve-like structure in the upper jaw made of ***اضغط على هذا الرابط*** keratin, which they use to filter ***اضغط على هذا الرابط*** plankton from the water. They are the largest suborder of whale.
The ***اضغط على هذا الرابط*** toothed whales have teeth and prey on fish, squid, or both. An outstanding ability of this group is to sense their surrounding environment through ***اضغط على هذا الرابط*** echo********.
Whales are special mammals

Like all mammals, whales breathe air into ***اضغط على هذا الرابط*** lungs, are ***اضغط على هذا الرابط*** warm-blooded, feed their young ***اضغط على هذا الرابط*** milk from ***اضغط على هذا الرابط*** mammary glands, and have some (although very little) hair.
Whales have a four-chambered ***اضغط على هذا الرابط*** heart. The ***اضغط على هذا الرابط*** neck ***اضغط على هذا الرابط*** vertebrae are fused in most whales, which provide stability during ***اضغط على هذا الرابط*** swimming at the expense of flexibility.
Whales also communicate with each other using lyrical sounds, called ***اضغط على هذا الرابط*** whale song. Being so large and powerful, these sounds are also extremely loud.
Females give birth to a single calf. Nursing time is long (more than one year in many species), which is associated with a strong bond between mother and young.

Whales are widely classed as ***اضغط على هذا الرابط*** predators, but their food ranges from microscopic ***اضغط على هذا الرابط*** plankton to very large fish.

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How long whales live
The ***اضغط على هذا الرابط*** Whale is the largest known mammal that has ever lived, and the largest living animal, at up to 35 m (105ft) long and 150 tons. Whales generally live for 40-90 years depending on their species and on rare occasions can be found to live over a century.

What may cause its extinction
Some species of large whales are endangered. This situation is due to:
1/ Whaling
For centuries whales have been hunted for meat and as a source of valuable raw materials. By the middle of the 20th century, large-scale industrial ***اضغط على هذا الرابط*** whaling had left many populations severely depleted, rendering certain ***اضغط على هذا الرابط*** species seriously ***اضغط على هذا الرابط*** endangered. Some species of large whales are endangered as a result of commercial ***اضغط على هذا الرابط*** whaling from the eleventh century to the twentieth. For centuries large whales have been hunted for ***اضغط على هذا الرابط*** oil, ***اضغط على هذا الرابط*** meat, ***اضغط على هذا الرابط*** baleen and ***اضغط على هذا الرابط*** ambergris (a perfume ingredient from the intestine of ***اضغط على هذا الرابط*** sperm whales). By the middle of the 20th century, whaling left many populations severely depleted.
2/ Sonar interference
Environmentalists have long speculated that some cetaceans, including whales, are endangered by ***اضغط على هذا الرابط*** sonar used by advanced navies. In 2003 British and Spanish scientists suggested in ***اضغط على هذا الرابط*** Nature that sonar is

connected to whale beaching and to signs that the beached whales have experienced decompression sickness.
3/ Seismic testing
Conservationists are concerned that seismic testing used for oil and gas exploration may damage the hearing and echo******** capabilities of whales and suggest that such testing may also be responsible for beaching.
4/ Other human activities
Other human activities have been suggested to adversely impact whale populations, ranging from the unregulated use of fishing gear which catches anything that swims into it, to collisions with ships. Environmental toxins and the combination of toxins, particularly ***اضغط على هذا الرابط*** POPs (which concentrate up the food chain), have been shown to cause hearing loss by inhibiting the function of outer ***اضغط على هذا الرابط*** hair cells in the ***اضغط على هذا الرابط*** cochlea of the ear, and exposure to these toxins might affect whale echo********, leading to beaching.
5/ ***اضغط على هذا الرابط*** climate change and ***اضغط على هذا الرابط*** global warming
Whales are also threatened by ***اضغط على هذا الرابط*** climate change and ***اضغط على هذا الرابط*** global warming. As the ***اضغط على هذا الرابط*** Antarctic Ocean warms, ***اضغط على هذا الرابط*** krill populations, that are the main food source of some species of whales, reduce dramatically, being replaced by jelly like ***اضغط على هذا الرابط*** slaps .

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What we can do to save the whale
The ***اضغط على هذا الرابط*** International Whaling Commission introduced a six year moratorium on all commercial whaling in 1986, which has been extended to the present day. For various reasons some exceptions to this moratorium exist; current whaling nations are ***اضغط على هذا الرابط*** Norway, ***اضغط على هذا الرابط*** Iceland and ***اضغط على هذا الرابط*** Japan and the aboriginal communities of ***اضغط على هذا الرابط*** Siberia, ***اضغط على هذا الرابط*** Alaska and northern ***اضغط على هذا الرابط*** Canada. For details, see ***اضغط على هذا الرابط*** whaling.
Fishing gear and deployment modifications and ***اضغط على هذا الرابط*** eco-labeling have contributed to a reduction in the mortality of whales in recent years.
We, consumers, have to boycott goods made of whale parts.
We have also to exert pressure on governments so as they pass laws limiting whale fishing.

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