The largest animals to ever live on earth weren’t some massive dino that we hear stories about. Incredibly, the largest animals ever are currently swimming in oceans all over the world! The blue whale is the largest animal by weight and length in the world (and it’s not really close). Sadly, these whales aren’t doing too well across the world, and humans are mostly to blame. Let’s take a look at the Blue Whale Population: How Many Blue Whales Are There in the World?
Blue Whale Overview
Before we get into the details of how many blue whales are left, let’s learn a bit about these fascinating animals.
When it comes to size, blue whales are the kings of the world. They hold the top spot as the largest creature to ever exist, never mind the largest whale or mammal. There are over 88 whales that are longer than 98 feet and at least one that is over 100 feet. The highest recorded weight of a blue whale is around 190 metric tons or 418,878 lbs. On average, however, blue whales measure around 75 feet long and weigh around 235,000 lbs. Regardless, they are huge.
Blue whales are the baleen whales, meaning they get their food by filtering water through their long “mouth whiskers” that are known as baleen. After gulping a load of water, the whale then pushes it through the filter, leaving the fish, nutrients, and krill behind for them to eat. Using this method, blue whales eat about 16 tons of food a day. A number that’s almost hard to conceptualize.
Blue whales and hunting
These creatures have a long history, especially with humans. Whaling, the process of hunting and processing whales for meat, fat, oil, and other resources has been a part of human culture for a long time. Blue whales were historically safe from this practice due to their size, but once the exploding harpoon gun was invented in 1864, humans could finally target these behemoths. Soon, up to 30,000 blue whales were being harvested a year, peaking in 1931. The practice was banned in many countries in 1966, but many other countries continued the practice into the 1970s.
This hunting, along with other human-caused threats, has dramatically impacted blue whale populations worldwide. Let’s take a look at their global populations and what the future looks like.
How Many Blue Whales are left in the World?
There are between 10,000 and 25,000 blue whales left in the world.
Blue whales have been around for millions of years, but their numbers are threatened across the world. The most significant impact on blue whale populations worldwide was, without a doubt, whaling efforts in the 20th century. Scientific population estimates place the pre-whaling global blue whale population at around 350,000 individuals, meaning that 99% of all blue whales were killed in the last 200 years.
The southern hemisphere is home to blue whales and currently has a population of around 5-10,000 individuals. Current blue whale populations in the northern hemisphere are between 3-4,000.
Where do blue whales live?
Blue whales are extremely widespread whales and can be found in nearly all of the world’s oceans. Part of the reason they are so widespread is that they are constantly migrating and roam within a large range. The only places you aren’t likely to find blue whales are in the Mediterranean Sea and in the furthest northern reaches of the Arctic. Besides that, they can be found nearly everywhere else, including waters around Antarctica.
What are the different blue whale populations?
Like most widespread animal species, there are different population groups that have been isolated by distance. Additionally, there are subspecies of blue whales that can be quite different from one another. Let’s take a look at these subspecies, where they live, and their estimated populations.
Northern subspecies (4-8,000)
There are three population groups that are classified as northern blue whales (B. m. musculus):
- North Atlantic populations range from eastern Canada up to Greenland, especially around the Gulf of St. Lawrence. This population migrates, but many remain year-round. Those that do migrate likely head to the West Indies and northwest Africa.
- Eastern North Pacific populations primarily range around California, Oregon, Washington, and Alaska. During the cold months of the year, they head to the Gulf of California and down near Costa Rica.
- Central/Western Pacific populations live around the Kamchatka Peninsula (the region of Russia that sticks out just above Japan). During the cold months, these whales migrate to Hawaiian and around the Gulf of Alaska.
Northern Indian Ocean subspecies
There is only one population of northern Indian Ocean blue whales (B. m. indica). They are generally found around the northwestern Indian Ocean and remain in this region year-round.
Pygmy blue whale (2-5,000)
There are three populations of pygmy blue whales (B. m. brevicauda).
- Madagascar populations migrate between the Seychelles and Amirante Islands to the Crozet and Prince Edward Islands.
- Australia and Indonesian populations spend the cold months in Indonesia and travel to Western Australia in the summer.
- Eastern Australian and New Zealand populations spend their winter around the Tasman Sea and the Lau Basin and the warm months around the South Taranaki Bight. Blue whales can live year-round along the coast of New Zealand.
Antarctic subspecies (5-8,000)
There is only one population of Antarctic blue whales (B. m. intermedia). These whales are found all across the Southern Ocean and occasionally travel as far north as the tropical Pacific and the Indian Ocean.
Are blue whales increasing or decreasing in number?
The various populations of blue whales vary, but there seems to be some decent news for blue whales globally. Blue whale numbers from 1991-2004 seemed to be pretty level. Recently, however, it looks like blue whale populations have been increasing by 7-8% each year for the past decade.
What does the future look like for blue whales?
Thankfully, with the international protection provided to these magnificent animals, numbers seem to be slowly increasing. It will take generations for them to climb out of their current Endangered listing, but all signs are looking good. Still, boat strikes, pollution, and climate change could threaten this species once again.