In the ocean, different animals have their own unique self-defence strategies to help them survive predators. Some, like crustaceans have hard shells to protect their vulnerable parts. Others go on the offensive; for example, blue-ringed octopuses strike back at attackers with a venomous bite.
Some critters active stealth mode: octopuses blend into their background using camouflage while pygmy sperm whales spurt dark red intestinal fluid into the water, like a smokescreen, to give them a chance to vanish in the confusion.
The largest animal in the world – the blue whale – is protected from most assailants by its sheer size. At up to 33 metres long, these epic animals are longer than a tennis court. Calves weigh around the same as an African elephant and females can grow to around 180,000kg – more than a Boeing 737. It’s no surprise that most animals don’t try to take them on.
Can any animal kill a blue whale?
But there is one species that can overcome a blue whale: orcas. Often considered the ocean’s apex predator, killer whales hunt many other animals, from small fish and salmon to sharks and marine mammals, such as seals, dolphins and whales (depending on their ecotype – different types of killer whales have different diets). Some orcas have even learned how to kill great white sharks – snacking on just their liver and leaving the rest of the carcass.
- “No other predator is able to challenge them” – this deadly, intelligent ocean killer works in a team to stun, submerge and launch at its prey
- At a staggering 33 metres long it's not only the biggest animal in the world today, it is the biggest animal to have ever lived...
Although clever killer whales often pick off weaker and more vulnerable animals, such as whale calves, a pod has been recorded killing an adult blue whale. Scientists came across the incident by accident and were astonished to witness a pod of around 14 killer whales worked together to kill an 18-22m long blue whale, who seemed otherwise healthy.
The huge carcass sank to the seafloor but the killer whales didn’t let that stop their feast: the researchers saw the orcas diving down and returning to the surface with mouthfuls of flesh, sharing their bounty with their pod-mates.
Other animals would have benefited from this kill too. Although other species don’t actively hunt blue whales, many scavengers make the most of the carcass bringing important nutrients down to the seabed. This banquet is an important part of the food web and is known as whale fall.
There’s one other animal that’s capable of killing graceful blue whales: humans. Before commercial whaling was banned, hundreds of thousands of blue whales were killed (nearly 30,000 of those were slaughtered in the 1930-31 season alone). Thankfully, their numbers are now recovering.
