Caribbean monk seals, the sea dwellers first discovered during Columbus’s second voyage in 1494, are officially extinct—the only seal to vanish because of human causes, MSNBC reports. “Humans left the Caribbean monk seal population unsustainable after overhunting them,” a biologist explained. The seal, a native of the Caribbean Sea and Gulf of Mexico, hadn’t been spotted for 50 years.
"The fate of the Caribbean monk seal is a wake-up call for us to act quickly to protect other endangered monk seal populations," said one advocate. Its cousins, the Hawaiian and Mediterranean monk seals, face dwindling populations. About 1,700 exist between the two species.