The bow of the tourist icebreaker Aurora plows through drift ice off the coast of Japan's Shiretoko Peninsula. Between January and April visitors flock to towns along the peninsula's coast to see and sometimes step out onto Arctic drift ice.

"If you just look at the last five years of data, the amount of drift ice is decreasing," said tour company director Takashi Yamamoto.

"It's a headache for us," he said. "If this continues, we are going to be in trouble ten years from now. Perhaps we need to think about a different kind of business."

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