A new study using fish DNA suggests that some species of tuna, particularly those used by restaurants, have higher mercury levels. Restaurants tend to favour certain species of tuna, such as Bluefin, Akami and Bigeye tuna. Unfortunately, mercury tends to accumulate to a greater degree in muscle than in fat, rendering these highly prized, leaner species of tuna more susceptible to high contamination. Restaurants tend to buy larger sized fish, which in turn contain larger concentrations of mercury due to their size.
Source: Biology Letters April 21, 2010 [Epub ahead of print]
