* Whales are diverse: There are over 90 different species of whales, and their diets vary greatly.
* Some whales are not fish eaters: Baleen whales, like humpbacks and blue whales, filter-feed on krill, plankton, and small fish.
* Others specialize: Some toothed whales, like dolphins, are primarily fish eaters. Others, like sperm whales, feed on squid.
* Population changes: Whale populations fluctuate, so the number of fish-eating whales changes over time.
Instead of focusing on an exact number, it's more helpful to understand that many whales are important parts of the marine food web and consume large quantities of fish.