Why do sharks leave blue whales alone? Couldn't they just rip some parts off the slow, helpless whale?

There are several reasons why sharks typically leave blue whales alone:

Size and Strength: Blue whales are the largest animals on Earth, reaching lengths of up to 100 feet and weights of up to 200 tons. Their sheer size and strength make them formidable opponents for most predators, including sharks. Even the largest sharks, such as the great white shark, would have difficulty overpowering a fully-grown blue whale.

Defence Mechanisms: Blue whales are not defenceless. While they may not actively defend themselves against predators, they possess thick blubber layers and tough skin that can provide some protection against attacks. Additionally, blue whales are capable of using their massive size and powerful tail flukes to defend themselves or flee from potential threats.

Feeding Preferences: Sharks typically prey on smaller, more manageable prey that they can overpower more easily. Blue whales are not part of the typical prey spectrum for most shark species. Sharks are more likely to target smaller marine animals, such as fish, seals, or smaller whales that require less effort to capture and consume.

Energy Efficiency: Hunting and attacking a blue whale would require a significant amount of energy expenditure for a shark. Given the size and speed of blue whales, as well as the potential risk of injury to the shark during an attack, it may not be worth the effort or risk for a shark to target a blue whale as prey.

Overall, while sharks are opportunistic predators and may occasionally scavenge on dead or injured blue whales, they generally avoid actively hunting or attacking these massive marine mammals due to the inherent challenges and risks involved.