Remi Foubert-Allen wanted to see killer whales for as long as he could remember. But he was completely unprepared when they swam past his boat in Hudson Bay near his hometown of Churchill, Manitoba. “I can’t believe I’m looking at orcas!” he shouted over the noise of his outboard motor. “Oh man, my dad is going to be so jealous.” Foubert-Allen—a zodiac driver with Sea North Tours—is understandably astonished. Killer whales in Hudson Bay were unheard of until recently. European explorers who wrote of their adventures in the area beginning in the early 1600s made no mention of the whales before 1900. But between the turn of the last century and 1960, explorers and Inuit hunters living along the bay began reporting the odd sighting—just a handful really. Since then, there has been a small but steady increase, leading to a peak of 40 sightings in the last five years. Steve Ferguson, a biologist with Fisheries and Ocean Canada, is among those trying to figure out what it all means. His research shows climate change—in the form of declining summer sea ice in the Hudson Strait—is likely responsible for killer whales from the Northwest Atlantic finding their way into the bay. That’s because the whales generally avoid ice. Their tall dorsal fins can get stuck as they swim underneath.