Why Are They Endangered?
The North Atlantic Right Whale is one of the most endangered whale species, first listed in 1970 under the Endangered Species Act; there are many factors that affect their decline, along with other whale species, but these two are the most detrimental and one continues to cause distress amongst the remaining population.
Ship Collision via: Gary Mansfield/CBC
Human Direct / Indirect Detriment
Whaling
Prior to the Endangered Species Act in 1970 - 1971 and the formation of the International Whaling Commission in 1946, whaling was prevalent amongst many types of whales, though these Right Whales were favored due to the amount of blubber they carried, and the fact that it made it easy to retrieve as these whales did not sink when killed. Whaling exterminated almost the entire global population, of Northern Atlantic Right Whales, done easily on these whales because they are known to be outgoing whales, seen on the surface a lot and near shores.
Fishing Gear Entanglement
According to the National Oceanic and Atmospheric Administration, roughly 85% of all Right Whales have been previously entangled to fishing gear at least once; why is this such a concern? These entanglements not only restricts the whale's movement, but due to the tightness, leaves permanent open wounds that can become infected and slowly kill the whale, or cause further life obstructions further down its life time. Procedures to remove entanglements can cause high stress to the whale, further damaging its mental to live a happy life.
Collisions
Due to the "friendly" nature of these whales, and the fact that their migration routes are very near other shipping lanes, they roam near the surface very often, and are not timid at all, so big ships that come near these whales easily ram into them if not seen. The picture to the left is that of a whale that was rammed into by a large ship, also taking into the account the fact that these whales don't move as fast as others, it is hard to avoid a very fast ship heading straight towards a 40 - 55ft long whale.
via: ifaw
Marine Climate Change
Along with many other ocean species, the Northern Atlantic Right Whale is getting detrimentally affected by climate change as an indirect result of global warming; not only does ocean warming affect the whale's livable environment as they are very picky with changes, but the ocean warming poses a large threat to one of their main sources of prey, this being krill / krill larvae. North Atlantic Right Whales have tended to change their routes along the east coast as more prey become less abundant, which sometimes leads to these whales search in areas that are not protected from invasive ship travel, which leads to being struck. Krill populations have declined by almost 80% in the northern Antarctic Peninsula since the 1970s, studies showing that the lack of abundant food sources leads to a decline in reproductive performance. These whale mothers are having less calves and are expected to have calves every 6 - 10 years instead of every 3 - 5 years due to the lowering abundance of food for energy. There is a direct correlation between a decrease in prey and the population of predator, especially when krill fuel many species in the ocean. With current global warming / climate change trends, these whales are expected to be wiped out in the near future, even without the inclusion of collisions with ships or entanglements.
via: Virginia Institute of Marine Science