Some of the most sustainable choices, according to Seafood Watch, include wild Alaskan salmon, farmed Arctic char, and U.S.-farmed shrimp and catfish.

WSJ: Guidelines for Eating Sustainable Seafood

The American Seafood Distributors Association, of which Mr Stevens is president, maintains that farmed shrimp is more consistent in size and quality than domestic shrimp.

ECONOMIST: A very big row over very small creatures