Killer Whales and Global Warming
Killer Whales and Climate Change
The consequences and effects of global warming have reached most of the species on earth, including us of course.
The Orca (Orcinus orca), is not exempt from the effects of climate change, which may have implications for this species greater than initially considered.
It is widely known that Killer whales have a wide food spectrum; they hunt seals, sea lions and other marine mammals. They have to travel over large regions of the ocean in search of this type of prey and to reach the areas where they live.
However, scientists have discovered three different eating habits in Killer whales leading some experts like Dr. Robert Pitman of NOAA (National Oceanic and Atmospheric Administration) to think that there are three different species of Orcas.
Dr. Pitman, stated in its investigation of more than ten years, that the first group feeds on marine mammals, penguins and other fish found in the open sea. The second type feeds mainly on fish living under the ice shelves, and the third type are fed hunting Minke Whales.
If these three types of whales are three different species or are only in the way to becoming separate species, yet is not fully agreed by the scientific community, but they already consider these three types of Killer whales.
Killer whales feeding on fish living under the ice have developed the habit of staying in the area as they do not need to travel in search of food. Fish usually group into schools under the ice as protection against predators.
This feeding habit makes evident that a decrease in the Antarctic ice will cause a decrease in the habitat of this type of Orca, but consequently, there will be undoubtedly a decrease in the amount of food available in the area.
If this type of Orca will be able easily to adapt to other living patterns is still unknown. Therefore, global warming can greatly contribute to the reduction or even extinction of this type of Killer Whale.
Another case of the drawbacks caused by climate change, was a well known case occurred in 2013 in the frozen Hudson Bay in Canada, where two adult Orcas and nine youths were caught in a small hole in the ice of the bay, with no escape chances.
Although this story came to a happy ending thanks to a change in the currents that opened a passage in the ice to the open sea, experts think that these cases will increase and are also caused by global warming.
Typically, the amount of ice in the Arctic make Killer whales to leave the area before winter and venture to hunt in the open ocean, but a decrease of ice in the area has made these cetaceans dare to enter into areas that normally would have already left by January.
A thirdly recorded case of the impact of global warming on Killer whales is related with the orcas that live from May to October in Puget Sound in Washington state. This group known as “Southern Resident killer whales” has been declared as “Endangered” by the agency National Marine Fisheries Services (NMFS) by registering a reduction in its population and its main food source.
According to experts, the dramatic reduction in the amount of Chinook salmon, the main food of this sub-population, has been the cause of this.
The salmon population has been reduced by a decrease in the amount of food available in the oceans, caused by ocean warming and by the increase up to 1.8 degrees in the temperature of some rivers, which has boosted the mortality rate of this and other species salmon in the region, with disastrous consequences for the other species in the food chain.
It is clear that global warming affects all living organisms on the planet. As before, with all major changes that Earth has faced, some species will be benefited, and some others will be severely affected. The ability to adapt quickly to other food and habitat patterns will be essential to ensure their survival regardless the imminent increase in global temperatures.