Eating sushi is part of the Southern California lifestyle. There's even a sushi roll named after us -- the classic California Roll.
Tuna is low in fat and calories, and high in cancer fighting omega-3 fatty acids. Those health attributes were the reason Academy Award-winning director Fischer Stevens says he was eating tuna three to four times a week, but he says it wasn't making him feel so healthy.
"I was feeling a little run down and I went to my nutritionist. He took my blood; I got a call from the New York Board of Health saying your mercury level count is really high," Stevens told NBCLA.
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The government says tuna and some other large predatory fish can be high in mercury. The FDA warns pregnant women and children to "limit" or "avoid" high-mercury fish because it can harm the nervous system of unborn babies and children.
Fisher says his mercury poisoning helped inspire him to direct the Oscar winning-documentary "The Cove," which graphically depicts the controversy of Japanese dolphin fishing.
Fisher admits his mercury and his politics are intertwined: "There's the mercury and then there's the issue of tuna being extinct because we're eating it so rapidly."
And Stevens isn't alone. Buffy Martin Tarbox works for GotMercury.org and she doesn't want you to eat tuna either.
"We were formed in 2002 with the purpose to educate the public about the dangers of mercury in fish," says Tarbox.
GotMercury.org is a San Francisco-based advocacy group trying to save the sea turtles that get stuck in the commercial fishing lines used to catch tuna.
One is fighting for dolphins; the other is fighting for sea turtles. Both use the issue of the "mercury in fish" to make their point.
Tarbox wants labels and warning signs about mercury wherever fish is sold. As part of the GotMercury.org campaign, the group routinely tests fish in California to show how mercury levels vary even within the same type of fish.
GotMercury.org gave us exclusive access to its most recent survey of sushi in Southern California before they released their report to the public. Tarbox collected tuna samples from 10 different restaurants from Newport Beach to Woodland Hills. She sampled one piece of tuna sashimi from each during a six-day period in April.
"The highest level of mercury we found in the sushi that we tested was a piece of ahi tuna sushi from Katsuya in Glendale. One piece was two times over the FDA limit," Tarbox reported.
She also noted that a piece of tuna from Midori sushi in Studio City tested above the limit as well.
Midori didn't respond, but Katsuya sent us an email saying they meet the highest standards of quality, but certain types of fish can contain high levels of mercury. Big-eyed tunas, which happen to be the most popular, have some mercury. Katsuya says guests who are concerned should, "follow FDA guidelines."
The restaurant with the lowest mercury reading was Kingyo Sushi in Newport Beach.
The survey indicates of all the sushi tested, 20 percent (or one in five pieces of sushi) was above the federal limits. Additionally, "six of them came in just immediately under the limit," according to Tarbox.
The FDA says this is normal, but you rarely eat just one piece of sushi, and what if you eat a lot of fish that approaches the FDA limit?
"It's an accumulation that's the problem. So the more high-mercury fish you eat, the higher your mercury is going to be in the body," warns Dr. Jane Hightower, one of the leading experts on the health effects of eating too much mercury.
Dr. Hightower advocates consumers: "Eat more fish, with less mercury."
Government health experts say all fish have some mercury, because mercury is everywhere in the environment, both naturally occurring and from pollution.
"The quantity of sushi you would have to eat to get astronomically high levels in your system is almost unrealistic," argues Gavin Gibbson of the national fisheries institute.
"The vast majority of commercial seafood has very low, and in some cases, undetectable amounts of mercury in them," Gibbson assures.