The blue whale is the loudest, largest, longest, and heaviest animal Earth has ever seen. This marine mammal consumes up to 8,000 lbs. of krill each day, and predominantly resides in three main areas across the globe: northern Atlantic Ocean, North Pacific Ocean and the Southern Hemisphere. Blue whales play an important role in the overall health of the marine environment, and while they're at the top of the food chain, they still remain at risk.

As of 2018, the global blue whale population is estimated to be 5,000–15,000 mature individuals and 10,000-25,000 total. However, in comparison, there were at least 140,000 mature whales in 1926. In the 20th century, the main threat to blue whales was whaling. More than 340,000 were killed in the first half of the century, depleting 90% of the global population.

Commercial whaling of all species is now banned by the International Whaling Commission (IWC), however, climate change and its impact on krill - blue whales predominant diet - makes the animal particularly vulnerable. For this reason, the blue whale is currently listed on the IUCN Red List as Endangered under criteria A1abd.