Last week, a sperm whale was spotted in the Mediterranean Sea, a mile and a half off Herzliya Marina, just north of Tel Aviv. After a couple hours of observation by researchers from the Israel Marine Mammal Research and Assistance Center, they came to the conclusion that this was not a sperm whale, it was a gray whale, a species that doesn't exist in the Mediterranean! There have been no gray whales observed in the Atlantic Ocean since the 18th century. All gray whales live in the Pacific. Except this one. Some scientists think the retreat of ice in the Arctic led the confused whale into the Atlantic.
In other words, a summering gray whale north of Alaska, swimming eastward along the Alaska coast, may have been able to take advantage of ice-free conditions to continue swimming eastward, all the way through the Canadian Archipelago and west of Greenland, (or, perhaps more likely, westward, above Russia and Europe, via the Northeast Passage) until instinct instructed it to turn south and ultimately hang a left.Link
(image credit: Dr. Aviad Scheinin)