Many species of whale are under threat of extinction but the changes needed to ensure their survival are the same as the ones needed to ensure the continued survival of the planet as a whole.

All mammals breathe air into their lungs and whales are no exception. These aquatic mammals are descendants of mammals that have gone back to the sea and those huge creatures were of the order artiodacyla and they had many similarities to the modern day hippopotamus.

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Molecular biology and DNA testing gives convincing evidence for this connection and verifies that whales entered the water approximately 50 million years ago. Whales are divided into two broad groups called baleen and toothed whales. There was a third group but this is now totally extinct.

The first group of whales has a sieve like mesh at the back of the mouth which strains plankton and microscopic creatures from the water. This group contains the largest species of whales which seems strange because, logically, it would be expected that the larger species would feed of the larger, more substantial food source.

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The second group is the toothed whale that preys on squid, fish or both. This is the group that has such a sensitive and accurate echo location system. This system is also known as biosonar and is also found in other mammals including dolphins, shrews and bats. Echo locating animals project sound and listen for the echo that comes back and this helps them to navigate, or hunt.

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Changes in the environment and the increasing use of sonar equipment on board ships has affected the toothed whales very badly. It disrupts their sonar so that hunting is not as effective and it misdirects their navigational abilities. This could be a major contribution to the disturbing incidences of whales beaching themselves, or getting stuck upstream in rivers.

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Whales are warm blooded creatures and they give birth to live young, just like other mammals do.

They feed their young milk from mammary glands and even have hair on their bodies. All these things are proof of the link with land mammals.

The body of the whale is like that of a fish but remnants of forelimbs can be seen in the creature’s front flippers. The tail holds the fluke which enables propulsion. Most whales do not have hind limbs but there are a couple of exceptions to this rule. Sperm whales and baleen whales sometimes have very simple back limbs. Most whales also have a dorsal or back fin.

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Beneath the skin of the whale is a thick layer of blubber, or fat, which provides insulation and it is for this fatty layer that whales have been hunted almost to extinction in some cases.

Whales breathe through blow holes which are located at the top of their heads. This location enables the whale to breathe and still remain submerged. Baleen whales have two blow holes and baleens have one. After a dive whales blow out water spouts which vary in shape according to species. A sperm whale can stay underwater for up to two hours without having to surface for air.

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The lifespan of the whale is estimated to be somewhere between thirty and ninety years depending on their species. However evidence of whales reaching more than one hundred years of age has also been found. In one particular instance part of a lance used by whalers in the 1800’s was found embedded in a bowhead whale which was caught off the coast of Alaska.

Male whales are known as bulls, females are called cows and their offspring are called cows and they tend to live in groups. Communication between whales is based on a series of sounds called whale song. These sounds are very loud because these are such large creatures and sperm whales have also been heard emitting a series of clicks. This is how these amazing creatures operate their inbuilt sonar system. They have been known to emit 20,000 watts of sound at 163 decibels. That’s a lot of noise when you consider that a blast from a shotgun reaches 130 decibels and a rocket launch generates 180 decibels. That places whale song somewhere between these two in volume.

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Whales do not usually form lasting bonds during the mating season and a cow may have several male partners during one season. Cows usually only give birth to one calf which is born tail first and suckles milk directly from its mother. Whale milk is a very thick, pasty substance and is actively squirted into the mouth of the suckling calf by the mother so that none of it gets lost in the water.

Sonar interference and whaling are endangering many whale species but these are not the only hazards they face. Seismic testing for oil and gas is thought to disrupt whale sonar and changes in the earth’s magnetic field may also be a factor in beaching. Fishing gear and collisions with ships frequently cause injury, or death and toxins known as persistent organic pollutants cause even more serious problems, These toxins can cause hearing loss in whales and so disrupt the fine tuning needed for their sonar operation.

Culturally whales have featured in stories and legends. For example in Pinocchio where the puppet and his father are swallowed by a whale and the tale of the great white whale, Moby Dick. The whale is mentioned in the Bible, ‘And God created great whales’, (Genesis 1:21) and in the Qur’an in the story of Jonah being swallowed by a great whale.

There are fourteen known species of baleen whales and of these the best known are Bowhead, Humpback Whale, Blue Whale and Grey Whale. The toothed whales number twenty six species including the Sperm Whale, Narwhal and Beluga.

A third group of whales is now thought to be extinct. The archaeoceti group were the forerunners to the modern whale. In 2004 fossils of an unknown extinct archeoceti were discovered and the species was named Harrison’s Whale after the discoverer. Sadly, not all extinct whales come from this group.

The Blue Whale is the world’s largest mammal and reaches up to thirty-three metres long with a weight of one hundred and ninety tonnes. It is thought to be the largest animal of any kind, ever to have lived on the earth. During the twentieth century, these creatures were hunted almost to distinction. In the middle of the 1960’s the blues were protected and this has helped their numbers to recover in the southern oceans. The last count was an estimated 2,300 and growth of about 7% per year has been seen since. (Figures courtesy of the BBC News Channel) and there is also evidence of an increase in numbers in the North Atlantic region.

The Bowhead Whale which is a particularly slow moving species has been protected since 1937. It grows up to 20 metres in length and inhabits the Arctic and Sub Arctic Seas. Although these whales are protected, native peoples are still permitted to hunt them for food. The Bowhead’s numbers are recovering in the Bering Sea, Chukchi and Beaufort Seas but the process is slower around Greenland and Baffin Island. It is thought that there are just 8000 Bowhead Whales in existence at this time.

The Fin Whale grows to about eighteen metres long and is found in north and south hemispheres. These creatures swim in pods of seven or eight individuals and eat mostly krill and herring. They have been so over fished and seen as a threat to herring fisherman that their numbers are sharply declining.

These are not the only threatened whale species. There are many more including the grey whale, humpback whale, and the Sei Whale. As our seas become more polluted and climate change plays havoc with food supplies for these creatures and other marine life we are in serious danger of killing these wonderful creatures off completely.

Coral reefs, their enormous variety of marine life and the sensitive eco systems surrounding them are also subject to the same destructive elements. Small changes in these areas have huge knock on effects in all the oceans of the world. This, combined with current changes, wind direction changes above the water have a far reaching effect on climate, drought and flood and so threaten our entire existence. Saving the whales now will have real long term benefits for the human race as a species. What is good for them now will eventually be food for us too.

It would be a very sad thing indeed if generations to come never saw whales, seahorses, walruses, penguins and starfish except in picture books, because we failed to do enough to protect them and their environment.

There is more at stake than preserving marine life and protecting whales because they are part of the same finely balanced eco system in which we live. The steps we need to take to make changes for these creatures are the same steps that are needed to save the very earth we live on and secure our own future as a species.