Why do whales eat a huge amount of small fishes instead of a few large ones?

Question

I remember watching a documentary once and learned that whales need to eat tonnes (literally) of krill per day to survive. I don’t understand why this is better than eating small amounts of large fishes instead.

In: 298

Answer 1

Because they would still need to eat tons of big fish.

There are far more krill by weight in the sea than there are big fish, so it’s a lot more efficient to eat the krill. After all, the big fish got big by eating smaller fish, so it just cuts a whole stage out.

Usually, bigger animals are herbivores, like elephants and hippopotamus. It’s more efficient to eat the species which create the energy in the first place, rather than eating things further up the food chain.