Which makes it all the more perplexing why three of the endangered animals washed up dead on the California coast, fatally shot sometime between late July and early August.

Between Aug. 12 and 19, the bodies of two young southern sea otters and an adult otter, all male, were discovered on shore near Santa Cruz Harbor, according to a California Department of Fish and Wildlife statement. Federal law protects marine mammals, including sea otters. It is also illegal to kill sea otters under California state legislation.

Only about 3,000 sea otters live in California waters, about 20 percent of what existed in the 1700s. The commercial fur trade claimed the otters in droves, causing the population to plummet, according to the International Union for Conservation of Nature. A fur treaty halted the pelt trade in 1911. But it was not until 1938, when a surviving colony of some 50 otters was found near Big Sur, that the California population began to turn around.

This group became the ancestors of all the state’s sea otters alive today. The population is stable, but research from the Monterey Bay Aquarium and U.S. Geological Survey indicates additional otter recovery is hampered by a lack of food. An oil spill remains a potentially devastating threat, but more typical hazards are predatory sharks.

And, for at least the three otters, a human with a gun.