The San Francisco Chronicle reported on the results from GotMercury.org's Operation Safe Seafood: California. Eighty one percent of swordfish tested from retailers in California were found to have mercury levels well above the FDA's mercury action level. Tuna came in second highest for mercury toxicity levels.
From the San Francisco Chronicle story:
Tuna and swordfish collected from some California grocery stores and
sushi restaurants contained mercury levels as much as three times the
threshold that authorizes federal food regulators to pull seafood from
shelves, according to a study by an environmental health group.
And despite pervasive concerns about the toxic heavy metal in fish,
not one of the restaurants and fewer than half of the grocery stores
displayed signs warning consumers about the risks of mercury exposure,
according to GotMercury.org, a public health advocacy group in San Francisco.
"They are selling food with high levels of mercury - levels the
federal government says are too high for children and pregnant women to
eat," said Buffy Martin Tarbox, lead author of the research. "And
consumers have no idea."