Are Whales at Threat of Extinction?

It is common knowledge that rampant overfishing (whaling) in the 18th - 20th centuries nearly drove many whale species to extinction. While whaling certainly existed prior to this, technological improvements allowed the industry to become much more efficient in harvesting whales. Now that the global whaling industry has nearly disappeared, whale populations have been able to slowly recover. Conservation efforts and eco-tourism (centered around whale watching cruises or dolphin interaction tours) are working to fund recovery efforts, but is it too late?

The majority of the great whale species are still on the endangered species list. The United States Endangered Species Act (ESA) still lists the northern right, southern right, bowhead, fin, blue, sei, humpback, and sperm whales as endangered species. The population of the northern right is reported to be less than one thousand animals remaining. One big problem is that, even without a major impact from commercial whaling, many interactions between humans and whales mean further losses in the population.

Commercial fishing vessels pose a great danger to whales. While their target is not the whale itself, the cetacean can often become entangled in the fishing lines or nets that are in active use or have been discarded at sea. This is not a fatal condition immediately, but the entanglement can slow down the animal, impacting its ability to dive and surface or to feed. A whale that cannot surface cannot breathe, and drowns.

Another impact from ships is collision risk. When large ships such as cruise liners or tankers collide with a whale, there is no contest. Serious injury or death is a frequent result. Many areas that are common "interference zones" between whale traffic and human traffic have implemented slower speeds to avoid the collisions, but this is not a 100% solution. There is currently no way to ensure keeping distance between ships and whales in their natural habitat.

The effects of climate change on all aspects of our environment are still not fully understood. However, as ocean temperatures change, the food source for many cetaceous mamals (krill and plankton) will be impacted. It is possible that ongoing temperature increases will create food shortages for the whale population, driving further losses.

Chemical and noise pollution are other factors impacting whale population rebound. Chemicals such as heavy metals make their way into the food chain and can build up over time, slowly poisoning the animals. Noise pollution, primarily from ship traffic, could possibly interfere with the navigation, feeding, and communication of whales. Interrupting these activities can further damage the recovery of whale stocks worldwide.

Finally, commercial whaling is still a minor factor. While a global moratorium on whaling has been declared, there is no central body with any enforcement authority. Annual harvests are closely monitored, and global opinion is largely negative about the practice, but some nations insist that whale hunting is part of their heritage.


Article Source: Denise Beresford