The jumbo scallops from the northern Japanese fishing town of Betsukai, on the island of Hokkaido, have a reputation for being among the most delicious on the planet, a cherished ingredient on a classic sushi plate.But for the past month, the Japanese government has exhorted the public to consume at least five of the delicacies daily to help draw down stocks that have piled up after Beijing banned imports of the bivalves in August.