Apex predators play a primary role in food webs by regulating the populations of prey species, thereby maintaining the health and balance of ecosystems. By controlling prey abundance, apex predators help prevent overgrazing or overpopulation of herbivores, which can lead to habitat degradation. Their presence contributes to trophic cascades, influencing the distribution and behavior of other species in the ecosystem. The removal or decline of apex predators can result in significant ecological imbalances, highlighting their importance in preserving biodiversity and promoting ecosystem resilience.