A US environmental group on Tuesday urged consumers to boycott bluefin tuna after a conference of major fishing nations left the eastern Atlantic catch largely unchanged.

The Center for Biological Diversity launched a campaign asking people to sign a pledge not to eat bluefin tuna or to patronize restaurants, among them some of the ritziest sushi joints in the United States, that serve the fish.

The 48-nation International Commission for the Conservation of Atlantic Tunas (ICCAT) last week rejected calls backed by the United States for a sharper reduction in the catch to ensure the species' survival.

"If regulators won't protect these magnificent fish, it's up to consumers and restaurants to eliminate the market demand, and that means refusing to eat, buy or serve this species," said Catherine Kilduff, a staff attorney for the advocacy group.

While the Paris meeting related to eastern Atlantic bluefin tuna, Kilduff said that the group was encouraging a boycott of all bluefin tuna varieties due to fears for the species' survival.

A number of countries including France and Japan, the world's largest tuna consumer, have dismissed calls to reduce the catch.

ICCAT scientists say that the latest catch levels will put eastern Atlantic bluefin on track for a 70 percent chance of reaching sustainability by 2022.

Some environmentalists say that those chances of survival are too low and point to revelations of a vast black market in bluefin tuna, which is highly prized in Japanese restaurants for its fatty "toro" belly.

Bluefin is one of five main species of tuna's Thunnus genus that make up the worldwide catch. Much of the tuna consumed is yellowfin or bigeye.

The most commonly eaten species is technically not Thunnus at all -- skipjack, a smaller fish which accounts for 60 percent of the world's annual "tuna" catch.