^w^ The large sharks are at the top of the ocean food chain. They feed on the large fish and promote the health of the other fish populations by weeding out the weak and injured.
^w^ It is impossible to predict exactly what would happen if the apex predators ceased to exist. Some species of large fish might grow to assume the apex predator role and the large fish population might expand.
^w^ Based on experience with land animals, scientists speculate that the increased numbers of big fish would quickly deplete their food source, the small fish, and the large fish populations would crash. It could take decades, even centuries, for the large fish to replace themselves.
^w^ The remaining small fish and crustaceans would barely make a dent in the `zooplankton` population. These tiny creatures might thrive, even increase until there were so many that their food source, the `phytoplankton`, would be depleted. If that happened, zooplankton, including the larvae of future small fishes, would starve.
