"It's lower in fat, it's lighter, it has the omega-3 fatty acids which are good for your heart," says Nancy Sullivan. She says her family eats fish because of its health benefits but as our undercover investigation is revealing often the fish you eat is not tested for hidden contaminants that could make you sick.
"About 85 percent of our fish supply is actually imported," says Joe Reardon. He's with the state department of agriculture. It's his job to make sure food in North Carolina grocery stores won't make you sick.
"If you go out to a supermarket and buy one of these products, we want to make sure that they're safe," says Reardon.
The state lab checks seafood samples for foreign antibiotics and other chemicals used to control algae in ponds. But Eyewitness News has learned the state does not test fish for heavy metals like mercury. So, we launched an undercover investigation to find out what could be in the fish you're eating.
We collected samples of fresh tuna and swordfish at three different Wake County grocery stores. We also bought one sample each of orange roughy, grouper and shark. We carefully labeled each sample, loaded them into a cooler filled with ice and drove them to the ElementOne Laboratory in Wilmington while making sure to keep the samples between 30 and 40 degrees.
"We do find mercury in fish," says Ken Smith. He runs ElementOne and says his lab equipment can find even the smallest amount of mercury, five parts per trillion.
"Normally it takes anywhere from 5 to ten working days to analyze fish," says Smith.
When the lab's results arrived we found many of the samples were contaminated with levels of mercury government agencies consider potentially dangerous. The FDA limit for human consumption is one part per million.
In North Carolina, the state health department says people should only eat one meal a week of fish high in mercury. That's fish ranging from .4 parts per million to one part per million.
It also says women of childbearing age and children under 15 should avoid fish in the high mercury range entirely.
All of the fresh tuna samples we collected at Wake County grocery stores measured within the high mercury range with one of them at .796.
The swordfish results were not any better. All three samples were in the state's high mercury range of .4 to one part per million with one of the samples registering .962 that's nearly the FDA limit.
The grouper sample had very little mercury but the orange roughy measured at just more than .6 parts per million. That's in the state's high mercury range.
The shark filet was the biggest surprise. The lab found 1.61 parts per million of mercury in the fish. That's more than the FDA limit.
In total, eight of our nine samples were in what the state health department considers the high mercury range and one was over the FDA mercury limit.
By comparison, Japan won't let many fish be sold if they have more than .4 parts per million of mercury. So, a lot of the fish we tested contained too much mercury to be sold in Japan.
"If you look at fish on the top of the food chain, those fish that eat other fish, and have lived a long time and are large, they are going to accumulate fairly high levels of mercury," says Dr. Sandy Stopford. He studies the effect of mercury on the human body at Duke University.
"Mercury in fish… tends to accumulate in the brain and nervous system and can interfere with brain function. So in children, you see a reduction in IQ, you see it deprecates their ability to perform well in school," says Dr. Stopford.
Dr. Stopford says women of childbearing age and children should not eat fish with the level of mercury we found in our study. He also says women and children should stay away from bigger fish that tend to accumulate more mercury.
Back in her kitchen in Cary, after seeing our report, Nancy Sullivan says she'll stick to smaller fish and limit the amount of fish they eat.
"I'd like to at least be informed about which fish I should be purchasing based on these mercury level tests, I mean that's dangerous, I would prefer to not feed that to my family," says Sullivan. She continues, "If mercury's a problem, it should be on the label or not be sold."
The state department of Agriculture tells us they could start testing fish for heavy metals like mercury in the future with more state funding.
The Kroger Store that sold us the shark with more mercury than the FDA limit says they have contacted their supplier for seafood to reinforce their standards and practices and are working closely to make sure they're fish meet FDA standards. The other two stores we tested, Lowes Foods and Harris Teeter, told us that their vendors check their fish to make sure that they are within FDA mercury guidelines. All of the stores told us that consumers should follow FDA guidelines regarding women and children and have posted information about these guidelines in their stores.
We want to be clear that there are fish that are lower in mercury or have virtually no mercury contamination. Fish like cod, halibut, mahi-mahi, salmon, tilapia and trout are all generally considered low in mercury and safe. For a complete list of fish that are safer to eat, Click Here(PDF).