A Seattle resident recently got a big surprise when she discovered a strange-looking furry visitor on her property.

"She woke up and it was lying on her dock, hanging out and sleeping — just chilling," said Matthew Cleland, district supervisor in western Washington for the USDA's Wildlife Services, and the recipient of a photo of the bizarre intruder.

"I thought, 'That's an interesting-looking creature,'" Cleland told OurAmazingPlanet. "I had no idea what it was."

A quick glance through a book in his office soon revealed it was a ribbon seal, an Arctic species that spends most of its life at sea, swimming the frigid waters off Alaska and Russia.

Somehow, the seal turned up on the woman's property, about a mile from the mouth of the Duwamish River, a highly industrialized waterway that cuts through southern Seattle. In 2001, the EPA declared the last 5.5 miles (9 kilometers) of the river a Superfund site — an area contaminated with hazardous substances in need of cleanup.

The sighting was "pretty exciting," said Arctic seal researcher Peter Boveng, leader of the National Marine Mammal Laboratory's Polar Ecosystems Program. "It's really unusual."

Read more: http://news.yahoo.com/rare-sea-creat...152011178.html