Question: whats the seas biggest preditor

James Bell answered on 19 Jun 2014:

The biggest predators are the whales by far. Blue and Fin whales are the most massive animals on the planet and mostly eat small fish and shrimp, many thousands of times smaller than themselves. All baleen whales eat tiny prey and can only grow so big because they ate millions of these animals in their lives. To understand why they do this, you need to know about how energy is transferred along a food chain. In a normal food chain, most of the biomass will be plants and about 10% of all the energy in plants gets transferred up to animals that eat the plants (the grazers). This 10% rule holds up fairly well level to level but once you get to a primary predator (one that eats grazers), there’s already only 1% of the total energy available. Baleen whales can grow so big because they feed lower down the food chain (eating the grazers) than other really big animals animals, so can get at more of the energy than if they ate other predators.

The biggest marine predator with proper teeth is the Sperm Whale which hunts fish and squid in the deep-sea. A big sperm whale can weigh around 60 tons – but a blue whale might weigh 200 tons!

Polar bears are probably the largest land predator, and they mostly eat seals, but they are still loads smaller than whales (although their diet is not the only reason for that).