Where do Killer Whales live?
Killer whales are cetaceans, which are distributed widely through all oceans of our planet. They have an anatomy with the amazing capability to withstand very cold sea temperatures and also to be part of tropical ecosystems. Studies have shown that after humans, orcas are the most distributed mammals in the world.
The most abundant populations are concentrated in waters with low temperatures, and this includes Antarctica, the North Atlantic and Northwest Pacific Ocean; this is mainly because in these areas the food is available in larger quantity.
Killer whales are not limited by salinity, temperature or depth of the sea, making them able to stay in deep waters and very close to the coast, where there are only a few meters of depth. Probably you have seen in some videos their incredible ability to reach the shore to capture sea lions and return to their habitat managing their impressive size and weight. Other cetaceans, without the risk of getting stranded, cannot perform this kind of bold performances.
Habitat
Orcas can go into almost any marine habitat, and some individual have been seen in coastal canals and river mouths. According to their geographical location, they share territory with multiple marine species, ranging from seals, penguins and sea lions to sea turtles, sharks and stingrays.
Sub-populations
Scientific research has been able to confirm the presence of several sub-populations of orcas and even some subspecies, whose eating habits, behavior, social, physical characteristics and habitat differ significantly. Five forms of Antarctic orcas that vary in habitat and region, and three forms or different ecotypes of killer whales in the Pacific have identified: residents, transients and offshore, which additionally can contain several internal populations (in the case of residents and transients).
Residents:
Two communities of resident killer whales are identified living within the first 800 km off the coast. They range from California to Russia.
Transients:
These orcas are distributed in coastal waters along the North Pacific on the west coast of North America from Alaska to southern California, where there is a large number of seals and porpoises.
Offshore:
They have a wide distribution covering the Northeast Pacific, extending from California to Mexican waters of the Pacific.
Migration
Killer whales are migratory species that move through the oceans according to the movement of fish, especially the herring or mackerel. Tracking research of North Atlantic orcas have shown changes in their distribution consistently with the movement of their prey. This kind of behavior was analyzed within the waters of Iceland, Norway and Scotland.
In contrast, the North Pacific killer whales move according to salmon migration. Antarctic orcas can make incredible journeys of more than 9,000 km from the white continent to the subtropical waters of Brazil while the Arctic orcas move according to heavy ice formations in order to avoid them.
Currently, the population of killer whales is unknown, but scientist believe that thanks to their wide distribution they are not endangered, although threats like global warming and marine pollution could be menacing some populations.
In February 2014, nine bodies of killer whales stranded in New Zealand coast were found, and the reasons for this tragedy are still unknown. There are many hypotheses about it, but none came to be probed, although the suspicion about chemicals in the ocean remains under investigation.