Blue whales are the largest mammals that ever lived, but they are also an endangered species. Due to aggressive hunting and environmental changes, these ocean-dwellers could become extinct.
Balaenoptera musculus, or the blue whales dominate the oceans, reaching lengths of 100 feet and weighing more than 200 tons. Their giant tongues alone can equal the weight of an elephant and their hearts can weigh as much as a car. These massive marine mammals get their spectacular size eating mostly tiny shrimplike creatures called krill. At certain times of the year, an adult blue whale consumes approximately 4 tons of krill daily.
Blue whales are baleen whales or filter feeders. Their upper jaws contain comb-like plates of material, called baleen. They eat by gulping a mouthful of water, then they press their tongue against theirs jaw to force the water thorough the baleen plates, leaving behind thousands of krill, which are then swallowed.
Under water, these massive sea creatures look true blue. Above water their skin is more a mottled blue-gray. Their underbellies have a yellowish hue from the millions of microorganisms that live in their skin.
Every ocean in the world is home to this endangered species. Blue whales occasionally swim in small groups but usually they swim alone or in pairs. In the summer they can be found in the polar regions and migrate south toward the Equator for the winter.
Graceful swimmers, these behemoths cruise at more than five miles per hour but can reach speeds over 20 miles per hour when agitated. They are of earth’s loudest animals emitting a series of pulses, groans and moans. Scientists believe that in good conditions, the can her each other at distances of up to 1,000 miles away. They believe these vocalizations are not only used for communication but also for navigating the dark depths of the oceans.
When they are born, blue whale calves are already one of the largest animals on the planet. Mother’s are pregnant for roughly a year, so baby blue whales are born weight up to three tons. And are about 25 feet long. Drinking nothing but their mothers’ milk the gain approximately 200 pounds a day for the first year.
Blue whales live longer than any other mammal Earth’s besides humans. They live an average of 80 to 90 years. Scientists discovered they could closely determine a whale’s age by counting its waxlike earplugs after it dies. The oldest blue whale found using this method was determined to be around 110 years old.
Only about 10,000 to 25,000 blue whales still swim in the world’s oceans. Soviet whaling ships hunted them aggressively for whale oil in the 1900s, causing them to nearly become extinct. The largest mammals that every lived became an endangered species when, from 1900 to the mid-1960s, about 360,000 blue whales were slaughtered. In 1966 they were placed on the protected list International Whaling Commission, which made commercial whaling illegal, but their numbers never recovered.
Blue whales don’t have many predators but, are known become victims of shark and killer whale attacks. Humans are also a threat to blue whales. Every year many sustain injuries from collisions with ships. Environmental change such as habitat loss and toxins in the ocean also threaten the massive marine mammals. Oil spills and garbage that collect in the oceans pose a risk to these great sea beasts.
Blue whales gained endangered status in 1986 by the World Conservation Union (IUCN) Red List, are still on the list today. Although they are the top of the food chain, the largest mammals that ever lived, blue whales have become an endangered species.
By Brandi M. Fleeks