At the Café des Arts, a beachside restaurant on Praslin island, sushi is on the menu – subject to the availability of fresh tuna.

Lately, the café has been steering its customers toward other kinds of fish. “I go out every day to see whether the fishermen have tuna,” says Robert Payet, its proprietor. “They know I’m willing to pay the top price, but they haven’t had a fish in three months.”