When sushi first became popular with Western diners it was touted as a guilt-free dinner, high in protein, relatively low in calories and fat, it quickly became wildly popular. Unfortunately all that popularity has led to rampant overfishing and now sushi is not looking quite so guilt free. The Telegraph reports that popular and expensive restaurant chain Nobu will now be highlighting their dishes which include bluefin tuna, a fish which as been listed as critically endangered by the International Union for the Conservation of Nature after decades of overfishing. The items will be marked with an asterisk and let people know that it is endangered.

The move comes after Greenpeace used DNA testing to prove that the Nobu restaurants in London were serving bluefin tuna without letting customers know they were eating the endangered fish. The restaurant has decided not to take the fish off the menu because the restaurant chain's chefs protested losing the chance to create with the delicious delicacy.

The restaurants, which are part-owned by Robert de Niro and sushi chef Nobu Matsuhisa, are popular celebrity haunts in New York, Los Angeles and London as well as other places around the world. Matsuhisa has been looking to switch over to supplying his chain with bluefin tuna farmed from the egg in Australia and Japan rather than fish harvested in the open ocean, a move that is likely to inflate Nobu's already hefty prices.