The environmental group Worldwide Fund for Nature is warning that illegal fishing is driving the bluefin tuna in the Mediterranean and East Atlantic to extinction.
The WWF says in a new report that annual fishing quotas for the bluefin are exceeded by more than 40 percent. It calls the European Union, Libyan, and Turkish fishing fleets the biggest offenders.
The report says some unreported bluefin catches are quickly processed at sea before being shipped to Japan, where the fish is one of the most popular portions of sushi dinners.
The WWF is urging European officials to call for an immediate halt to Atlantic bluefin fishing to give the species time to recover.
It says it will call for a consumer boycott in the United States and Japan if no action is taken.