Climate Change and Whales

Climate Change and Whales

The well-publicised report by the UN Intergovernmental Panel on Climate Change (IPCC) in October 2018 states bluntly that global temperature rises must be limited to 1.5 degrees centigrade, in order to avert catastrophic climate changes for humankind. All life on our planet is linked in a finely balanced ecosystem and, while it is humans causing the problems, it is all of Earth’s creatures that are threatened.

How Climate Change Happens

Solar radiation is trapped by greenhouse gases in the earth’s atmosphere, and at the optimum level, this captured heat is vital for our survival. However, the acceleration of industrialisation, and spiralling dependence on fossil fuels, has caused a massive increase in greenhouse gases pumped into the atmosphere, especially CO² (carbon dioxide). Additionally, the destruction of vast areas of forest results in fewer trees to absorb excess CO². Further, polar ice, which deflects excess heat from the planet, is melting at an unprecedented rate, further reducing the planet’s defences. Too much heat is trapped, causing climate change, which results in

  • warmer seas
  • stronger hurricanes
  • increased flooding
  • desertification
  • damage to sensitive eco-systems

 

Impact upon Whales

It is feared that the speed of climate change may leave some whale populations unable to adapt. Changes in water temperature and in food availability confound the ability of whales to behave normally. Many whale species follow certain migratory patterns, between warmer and colder waters, based on feeding, mating and birthing. Most whales can only live within narrow temperature ranges. The bowhead, beluga and narwhal, for example, live all year in Arctic waters, and warming threatens their food supply and their habitat. Krill, the main diet of many whales and many other creatures in the food chain, may be threatened by increased UV radiation. Other species fed upon by whales may themselves become dispersed to different areas because of disruption in food availability. Survival of some species of whale may depend on their ability to compensate and adapt; but it is not known how well they will be able to do this. For whales in the north Indian Ocean, for example, moving to cooler waters is not possible, as the ocean is fringed by land. One instance of whales being confused by climate change was reported in September 2018 by WWF marine biologist (Brandon Laforest) and his guide (Titus Allooloo). They noticed two sperm whales off Boffin Island in Canada. Sperm whales find it difficult to navigate in colder waters, usually keeping to warmer waters, but the cetaceans had been misled by the warming Arctic water. When ice forms, they could become trapped, as their bodies are not effective at breaking through ice.

Whales – our Allies

In allowing climate change to affect whales, the human race is also indirectly damaging itself. It was reported in the Scientific American (April 2017) that whales help mop up carbon by facilitating the growth of carbon-ingesting flora at the water’s surface.  Firstly, the movements of whales, particularly diving, push nutrients to the water’s surface. Secondly, whale plumes play a great role in this: the plume is actually whale excretion, another important source of nutrition for marine flora. This illustrates the complex interconnection of the ecosystems supporting all life on our planet.

Whales – our Allies

 

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