Threats to Whales

Imagine a century ago when parts of the sea teaming with whales. But human intervention changed this. The commercial whaling era killed millions of whales and made them into lubricants, cosmetics, margarine, and meal. Today, the sight of a whale is sporadic at best and totally absent in many locales previously populated by whales. For example :

• The Gray whale in the North Atlantic is extinct
  
• The Indus Susu, or Indian River dolphin, is barely hanging to its shrunken habitat
  
• The European stock of Bowhead whales, between east Greenland and Novaya Zemba, is almost extinct
  
• In the Northern Pacific Right whales, the Korean stock of Gray whales, and a small ("cochito") in the Gulf of California may soon be gone

No marine species remains unaffected by human activities. A viable population depends on the health of the ecosystem in which it exists, and the many forms of pollution extend to all the world's oceans threatening all species. Low level contamination of the smaller prey species becomes concentrated in the tissue of larger marine predators and apexes in marine mammals. Planktonic organisms are carried great distances by winds and sea currents and larger nektonic creatures travel large expanses of oceans on their own accord. Both carry pesticides, heavy-metals, and disease causing organisms to all sea areas. Contamination levels in seem toothed whales and dolphins are known to be high. How this affects their individual fitness or their ability to reproduce is still largely unknown.

The Beluga whale population of the St. Lawrence in Canada has been declining since protection in 1979.Through autopsies, researches have discovered high concentrations of PCB and DDT which are stored in the fatty tissues of mammals.Dead Belugas have revealed bladder and liver cancer which has never been seen before in marine mammals. Other diseases found in Belugas are hepatitis, splenic tumors, pneumonia, herpes,skin diseases, ulcers and blood poisoning, all which suggest suppression of the immune system.

Toxicologists based in New York have completed research on Elephant seals off Northern California coasts. they have found high levels of coplanar PCBs and skin diseases in this species. Along the west coast of the United States. autopsies of Bottlenose dolphins show high PCB and DDT levels.

In addition to chemical pollution, oil slicks are commonplace in the oceans. Somw whales and dolphins in the Western North Atlantic have been surfacing repeatedly through and oil slicked area.In contrast, Gray whales studies off of the Southern California coast changed their migratory path and their swimming and diving behavior when coming into contact with oil patches from seepage. Thousands of marine mammals are killed annually by gill nets and fish traps., Whaling practices common today in Norway, the Faroe Islands and Japan.

Noise pollution also threatens the existence of cetaceans. Large ships and boats make a tremendous amount of noise that falls into the same frequency range of many whales. This could be a contributing factor to the noticeable shift in the migration route of some California Gray whales. Some are making a detour around the west side of the Channel Islands, possible to avoid the noise pollution os Southern California sea traffic. Recent studies done in Newfoundland reveal that Humpback whales entangled in gill nets have damaged ears. Since sound plays a vital role in the life of whales, dolphins and porpoises, noise pollution must be considered significant, especially when it is of the magnitude of the Governments Ship Shock plans off the Southern California coast which were stopped by Save the Whales, and the poorly planned ATOC tests, watered down only after outraged protests by environmental groups and citizens.