Japan without fish is like Japan without Zen – less Japanese, somehow. Zen, for centuries scarcely separable from the Japanese mind, survives attenuated if at all. Fish, for millennia scarcely separable from the Japanese diet, hangs in the balance.

“Within five years fish will vanish from the Japanese table,” fears Josei Seven (Sept 12). That’s a worst-case scenario; it may not come to that. Even if it doesn’t, the fishing industry faces so many threats – economic, demographic, meteorological – that a flourishing future seems unlikely.

A pity. Fish is the perfect health food, and sea-girt Japan has been singularly blessed in that regard. Fishmongers crying their wares were a fixture of old Japan, mostly gone now, displaced by supermarkets less picturesque but purveying, economically and in abundance, species whose names are hardly known in less maritime lands.

Fifty years ago “raw fish” was a faintly repellent notion in the West. Who then could have foreseen that sushi would soon be as universal as pizza? Sushi as delicacy rapidly evolved into sushi as fast food, spreading outward from Japan’s kaitenzushi establishments. Fish in all its astonishing varieties is “Japanese soul food,” Josei Seven hears from fisheries analyst Momoro Kodaira.

Warming seas were the first portent of danger, ignored too long. “We first heard warnings of climate change decades ago,” says Tottori fisherman Nobuaki Kawanishi, “but only in the past few years have fish like .