Although the northern right whale (Eubalena glacialis) has remained the most endangered of the world's whale species, we removed it from our Top 10 Endangered Species List a few years back. Because of effective conservation regulations, the number of right whales that travel the Atlantic coasts of Canada and the US had rebounded (回升) from an all-time low of 350 to at least 450 by the middle of the 21st century's second decade.
However, the tide of good news for the species now seems to have been reversed, due, apparently, to global climate change. Warming ocean waters, particularly in the Gulf of Marine where the whales often feed, have caused kill-the tiny creatures right whales feed on - to decrease and become more difficult for the whales to find. As a result, right whale reproduction has fallen to an alarmingly low level, deaths due to all causes have increased, with 16 of the huge cetaceans (鲸鱼) found dead in 2017 alone. Researchers are finding evidence of increased levels of stress on the animals. So alarming is the situation that we've decided to put the northern right whale right back at the top of our list.
The right whale got its name because 19th century whalers considered it "right" whale to kill, as it was not only full of valuable whale oil, but it also floated after it was dead, which made it easy to handle and process. As a result, it was driven to near extinction. Though now protected by law, right whales continue to suffer losses due to commercial fishing-and now, increasingly, as a result of global climate change, due to the lack of the tiny crustaceans (甲壳类) on which they feed.
