blue | San Diego Whale Watch 1

Blue Whale

Balaenoptera Musculus


90-100 feet (27-30 m) in Southern Hemisphere
75-80 feet (23-24.5 m) in Northern Hemisphere


100-150 tons (100,000-136,000 kg)


Found in all oceans, they migrate to tropical waters during winter months to mate and give birth.


Endangered – 3,000-4,000 in N. Hemisphere; 5,000-10,000 in S. Hemisphere


The Blue Whale is the largest animal to have ever live on Earth. They are categorized as baleen whales and belong to a group of whales known as the rorquals (also includes Humpback Whales, Fin Whales, Bryde’s Whales, Sei Whales, and Minke Whales). Blue Whales have long throat grooves that expand while the animal is feeding. Blue-gray in color, the Blue Whale is long and slender with a tiny dorsal fin that is set far along the back, close to the tail-flukes.

Blue Whales filter-feed nearly exclusively on small shrimp-like critters called krill by trapping large masses of them in their baleen plates. They can eat up to 40 million krill each day. Blue Whales can be found alone or in small groups while in feeding or mating/birthing grounds. Although they can quicken the pace if alarmed, they typically travel at roughly 10-12 mph.

It is believed that the population of blue whales was once nearly 450,000. Unfortunately, due to excessive exploitation from the whaling industry, 99% of the population was killed off, leaving between 8,000-12,000 individuals remaining globally. It is no longer permitted to hunt whales of any kind in the United States, allowing for a slow recovery. Blue Whales are a critically endangered animal that only a small percent of the world will ever be lucky enough to see in the wild.