Whales: Giants of the Ocean Whales are among the largest and most remarkable animals on Earth. These marine mammals live in oceans around the world, from warm tropical waters to the cold seas surrounding the poles. Life Beneath the Surface Although whales spend their lives in water, they breathe air through blowholes located on top of their heads. They must regularly return to the surface to breathe before diving again in search of food or traveling through the ocean. Whales are warm-blooded, give birth to live young, and nurse their calves with milk. A thick layer of fat called blubber helps protect them from cold water and stores energy during long migrations. Two Main Groups Whales are generally divided into baleen whales and toothed whales. Baleen whales filter small animals from the water using flexible plates inside their mouths. This group includes blue whales, humpback whales, and gray whales. Toothed whales use teeth to catch fish, squid, and other prey. Many of them also use echolocation, producing sounds and listening for returning echoes to understand their surroundings. Sperm whales, belugas, and orcas belong to this group. The Blue Whale The blue whale is the largest known animal to have ever lived. An adult can grow longer than a city bus and weigh well over one hundred tonnes. Despite its enormous size, it feeds mainly on tiny crustaceans called krill. Communication and Migration Whales communicate using clicks, whistles, pulses, and complex songs. Some sounds can travel across great distances underwater. Humpback whales are especially famous for their long, patterned songs. Many species migrate thousands of kilometres each year. They often feed in cold, nutrient-rich waters before traveling to warmer regions where they mate and give birth. Protecting Whales Commercial hunting once caused severe declines in many whale populations. Today, whales also face threats from fishing gear, ship collisions, underwater noise, pollution, and changes to ocean ecosystems. Conservation programs, safer fishing practices, protected habitats, and international cooperation can help whale populations recover. Protecting whales also supports healthier oceans because these animals play an important role in marine food webs and nutrient cycles.