The Sei Whale
The sei whale (scientific name balaenoptera borealis) is a subspecies of great whale that inhabits every ocean and ocean-connected sea, except for those in polar and tropical areas. It can grow between 45 and 66 feet long, and it weighs about 40,000 pounds. It is one of the fastest subspecies of whale, swimming, at most, 30 miles per hour. Like other subspecies of great whale, it prefers to spend the summer feeding in the cooler parts of its habitat, then migrating to the warmer ones in order to conceive and birth offspring.
The sei whale is classified as an Endangered species. It is this close to becoming extinct for four reasons. The first reason is that it is hunted for scientific research done on whales in Japan. The second reason is that it is negatively impacted by climate change. The third reason is that it gets into collisions with ships. The fourth reason is that it gets entangled in fishing gear. Because of this, the World Wildlife Fund's (WWF's) effort to save it consists of working to make the International Whaling Commission (IWC) more effective in reducing these threats to it. This is being done because it plays an important role in the overall health of its habitat.
Source for picture and all information: https://www.worldwildlife.org/species/sei-whale