Escolar, right, is often substituted for more expensive Albacore tuna (left), a report on mislabeled seafood found. Yoon S. Byun/Boston Globe via Getty Images hide caption

itoggle caption Yoon S. Byun/Boston Globe via Getty Images

Swordfish from Canada are marked with a label from the Marine Stewardship Council at a Whole Foods in Washington, D.C. The MSC says its label means the fish were caught by a sustainable fishery, but critics says it's not always so clear. Margot Williams/NPR hide caption

itoggle caption Margot Williams/NPR

Farmed Atlantic salmon was sometimes labeled at "wild salmon," researchers found when the tested seafood sold in New York City. iStockphoto.com hide caption

itoggle caption iStockphoto.com

A Tokyo sushi restaurant displays blocks of fat meat tuna cut out from a 269kg bluefin tuna. Yoshikazu Tsuno/AFP/Getty Images hide caption

itoggle caption Yoshikazu Tsuno/AFP/Getty Images

An oyster shucker on Samish Island, Wash. on Puget Sound. The state is frequently forced to close beaches to oyster gatherers because of the risks of harmful algae blooms. Ted S. Warren/AP hide caption

itoggle caption Ted S. Warren/AP