What is a primary predator of sea urchins in coastal ecosystems?

Sea otters are recognized as primary predators of sea urchins in coastal ecosystems, particularly in kelp forest environments. They play a crucial role in maintaining the balance of these ecosystems. By preying on sea urchins, sea otters help to control their population, preventing overgrazing on kelp forests. If sea urchin populations are left unchecked, they can decimate kelp beds, which serve as vital habitats and food sources for a variety of marine species. The presence of sea otters thus contributes to the health and stability of coastal ecosystems, illustrating the interconnectedness of species and their roles within food webs.