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When you eat tuna, there’s a good chance you’re not actually eating tuna. Instead, the majority of fish labeled ‘white tuna’ may actually be escolar, a type of fish that can cause serious digestive effects, including oily anal leakage.

Oceana, the non-profit ocean protection group that revealed the findings, further found that nearly 60 percent of ‘tuna’ sold at restaurants and grocery stores is another type of fish entirely – and the results fared worst for sushi restaurants.

Love Sushi? Skip the So-Called ‘Tuna’ (Ahi)

Oceana conducted DNA testing on more than 1,200 fish samples across the US and found that one-third were mislabeled. While red snapper had the highest mislabeling rates (87 percent of ‘red snapper’ samples were not actually red snapper), tuna was a close second, with 59 percent mislabeled.

At sushi restaurants, however, 74 percent of fish samples were mislabeled. This included every single sushi restaurant from which samples were tested, even in major metropolitan areas like Chicago, Austin, New York and Washington DC.

According to Oceana’s 69-page report, in many cases the mislabeled fish had been substituted for cheaper, less desirable and/or more readily available fish varieties. The results showed that:

● Mislabeling was found in 27 of the 46 fish types tested (59 percent)     

● 87 percent of fish sold as snapper was actually some other type of fish     

● 59 percent of tuna was some other type of fish     

● 84 percent of “white tuna” sold in sushi venues was actually escolar, a fish associated with acute and serious digestive effects if you eat just a couple of ounces     

● Grouper, halibut, and red snapper were sometimes substituted with king mackerel and tile fish, two types of fish the FDA advises pregnant women and other sensitive groups to avoid due to dangerously high mercury content