Where do they live?

Blue Whales are generally solitary, though they may occasionally travel in small groups of two to four. Each year, they undertake an epic migration that makes them one of the ocean’s great travelers.

The migration period runs from May to November which makes this the best time to go whale watching on the Northern Beaches. From mid-May to mid-August, whales head north toward warmer tropical waters to breed and escape the harsh Antarctic winter. Then in mid-August they turn south again, with the journey concluding by late November.

In summer, Blue Whales feast on vast swarms of krill in the cold polar seas, storing up energy for the months ahead. Winter finds them in temperate and subtropical regions, where conditions are gentler. These giants repeat this cycle annually.

What do they eat?

The Blue Whale is a filter-feeder, and their diet is made up almost entirely of krill – tiny, shrimp-like crustaceans found throughout the world’s oceans. Despite their size, these little creatures fuel the largest animal on Earth. A single Blue Whale can consume up to four tonnes of krill in a day!

To feed, the whale lunges through dense swarms with its mouth wide open, swallowing more food in one gulp than any other animal alive. Their throat is equipped with expandable pleats allowing them to take in a huge amount of water and prey - more than its own body weight!

Once the water is inside, the whale’s enormous tongue pushes the water back out through strainer-like baleen plates, their version of teeth, that hang from the upper jaw. The krill are trapped inside, leaving the whale with a protein-packed meal. 

This remarkable feeding system makes the Blue Whale both a gentle giant and one of the most efficient hunters in the ocean.

What do they look like?

The Blue Whale is the undisputed giant of the animal kingdom, weighing up to 200 tonnes - roughly the same as 33 elephants. Their heart alone is the size of a small car.

With long, slender bodies mottled in grayish-blue, Blue Whales can be up to 30 meters long and live for more than 70 years. Females are generally larger than males, and every two to three years they give birth to a single calf.

Despite their immense size, Blue Whales are surprisingly agile. They can swim at speeds of up to 48 km/h, dive as deep as 500 meters, and remain underwater for 10 to 20 minutes at a time. 

How can you support the Blue Whale?

• Report any sightings of whales in distress to ORCCA via their website or on 02 9415 3333. 
• Keep your distance: If you see a whale in the water do not approach them and maintain a distance of at least 50 m. 
• Dispose of fishing line and gear appropriately: Whales can get entangled in fishing gear and marine debris.
• Slow down and keep an eye out when boating: This will also help conserve other species such as little penguins.
• Manage household chemicals: Use minimal amounts of fertilisers and pesticides on lawns and wash cars with water or eco-friendly soap to prevent chemicals from washing into our local waterways.
• Join local clean ups: Participate in local cleanup groups such as the Northern Beaches Clean Up Crew.

The Blue Whale is listed under the Environment Protection and Biodiversity Conservation Act, 1999 (EPBC Act) as endangered. 

They were abundant in nearly all the Earth's oceans until the end of the 19th century and were hunted to the point of near extinction by whalers, until a ban in 1966. The global population was estimated to be only 5,000 - 15,000 mature whales in 2018. They are now threatened by ship strikes, entanglement in commercial fishing gear, human made ocean noise (e.g. sonar), oceanic acidification (which affects krill) and pollutants.

Fun facts

• Fossil evidence shows that anatomically the modern Blue Whale has been around for at least 1.5 million years, with remains discovered in southern Italy.
• They rank among the loudest animals on Earth, producing calls that reach up to 188 decibels - far louder than a jet engine at 140 decibels. Their deep, low-frequency whistles can travel hundreds of kilometers through the ocean.
• Even their heartbeat is extraordinary: the slow thump of a Blue Whale’s heart can be detected from three kilometers away.