For the test, a total of 142 samples of tuna, swordfish and halibut were randomly and anonymously purchased during November and December 2007 in 19 leading supermarkets in Northern California and South Florida. MASI found that both the swordfish and the halibut tested had higher mean mercury levels, and higher maximum levels of mercury, than published government data indicate consumers should expect to find in these species. (See chart below.)

“We purchased the fish just as any consumer would, selecting these species because they are popular and known to have a higher mercury content than most fish – swordfish is known to have one of the highest average mercury levels, ” said Mal Wittenberg, MASI CEO. He noted that the findings in this test were consistent with the results of MASI ’s extensive testing of these species in fish processing plants over the past several years.

“Everyone agrees that it is beneficial to eat more seafood, and consumers should be able to enjoy popular fish like tuna, halibut and swordfish, but many consumers also are concerned about mercury, ” Wittenberg said. “Consumers need to have the information to make informed choices about how frequently and in what quantities they can reasonably consume certain species of fish. We believe if consumers have more confidence in seafood, they will enjoy it more frequently, and that is our goal. ”

MASI has conducted more than 50,000 mercury tests in the past three years in seafood processing plants in the U.S. and around the world using highly advanced new technology, giving the company a current database of tested fish that is unmatched in the world. MASI conducts seafood mercury testing for a number of leading retailers and also certifies seafood tested to be lower in mercury through its Safe Harbor Certified Seafood ® seal.

The seafood in this test was randomly purchased from supermarkets at intervals of three days or more to allow for product turnover. It was tested within 24 hours after purchase by MASI using technology with mercury detection sensitivity close to 10 parts per billion. MASI tested 63 ahi tuna, 41 swordfish and 38 halibut samples.