* Disease: Sea otters are susceptible to a variety of diseases, including bacterial infections, viral infections, and parasites. Some of these diseases can be fatal, especially to young sea otters.
* Starvation: Sea otters rely on a diet of kelp and other marine invertebrates. If their food supply is depleted, they can starve to death.
* Human activities: Sea otters can be killed by humans through several different mechanisms, including shooting, drowning, and entanglement in fishing gear.