With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: In a variety of marine environments, killer whales can be found.
text_B: The killer whale or orca -LRB- Orcinus orca -RRB- is a toothed whale belonging to the oceanic dolphin family , of which it is the largest member .. toothed whale. toothed whale. oceanic dolphin. oceanic dolphin. Killer whales have a diverse diet , although individual populations often specialize in particular types of prey .. Some feed exclusively on fish , while others hunt marine mammals such as seals and dolphins .. seals. pinniped. They have been known to attack baleen whale calves , and even adult whales .. baleen whale. baleen whale. Killer whales are apex predators , as there is no animal that preys on them .. Killer whales are considered a cosmopolitan species , and can be found in each of the world 's oceans in a variety of marine environments , from Arctic and Antarctic regions to tropical seas .. cosmopolitan species. cosmopolitan species. Arctic. Arctic Ocean. Antarctic regions. Southern Ocean. Killer whales are highly social ; some populations are composed of matrilineal family groups -LRB- pods -RRB- which are the most stable of any animal species .. social. social animal. matrilineal. matrilineal. Their sophisticated hunting techniques and vocal behaviours , which are often specific to a particular group and passed across generations , have been described as manifestations of animal culture .. animal culture. animal culture. The International Union for Conservation of Nature currently assesses the orca 's conservation status as data deficient because of the likelihood that two or more killer whale types are separate species .. International Union for Conservation of Nature. International Union for Conservation of Nature. conservation status. conservation status. data deficient. data deficient. separate species. Species problem. Some local populations are considered threatened or endangered due to prey depletion , habitat loss , pollution -LRB- by PCBs -RRB- , capture for marine mammal parks , and conflicts with human fisheries .. human. human. marine mammal. marine mammal. threatened. threatened species. endangered. endangered species. habitat loss. habitat loss. PCBs. Polychlorinated biphenyl. conflicts with human fisheries. Commercial fishing#Environmental Risk. In late 2005 , the Southern Resident Killer Whales , the population that inhabits British Columbia and Washington state waters , were placed on the U.S. Endangered Species list .. British Columbia. British Columbia. Washington state. Washington state. U.S. Endangered Species list. United States Fish and Wildlife Service list of endangered species of mammals and birds. Wild killer whales are not considered a threat to humans , but there have been cases of captive orcas killing or injuring their handlers at marine theme parks .. captive orcas killing or injuring their handlers. Killer whale attacks on humans#Captive orca attacks. Killer whales feature strongly in the mythologies of indigenous cultures , with their reputation ranging from being the souls of humans to merciless killers .
related.