Fish higher up the food chain contain more mercury

Though it’s impossible to say exactly why, seafood sales do appear to be slipping. The Food and Drug Administration’s advisory on mercury and 0sh consumption in March 2004 got lots of media attention. According to ACNielsen, volume sales of tuna sold in cans and envelopes fell 9% in the 12

months after the advisory, which singled out tuna. Information Resources

data show that for

the 52 weeks ending Oct. 2, sales in the refrigeratedseafood category fell 0.5% and 2.1% in 2004.

Worries that over 0 shing is depleting 0 sh populations may be having an effect on consumption, too. A survey of 400 visitors to the Monterey Bay Aquarium in California who picked up a Seafood Watch wallet- size guide to non-endangered 0 sh species found that 80% said they still buy less of certain types of seafood, even four months after their visit.

But there’s a real risk that warnings about a few 0 sh species directed only at a small portion of the population will get simpli 0 ed in the public mind to the mantra “ Don’t eat 0 sh,” says David Acheson, chief medical of 0 cer of the Food and Drug Administration From sh to foul

So how did 0 sh, once so abundant, healthful and even virtuous— remember that eating 0 sh on Friday was a Christian penitential observance — become the source of For public consumption: With abundant supplies in places like Seattle’s Pike Place Fish Market, consumers can choose from a variety of species. fear and guilt?

For mercury, the path goes back to recommendations 0 rst made in 2001 and updated in 2004; the FDA and Environmental Protection Agency said that some 0 sh have so much mercury that eating them could be dangerous to the developing brain of a fetus.

The FDA says pregnant women, women who might become pregnant and young children shouldn’t eat 0 sh with high levels of mercury — shark, sword0 sh, king mackerel or tile 0 sh — at all and shouldn’t have more than more than two meals a week of any kind of 0 sh.

And in a blow to the tuna industry, the FDA added that for those women and children, only one meal a week should be albacore, or white, tuna because its mercury levels are high enough that two servings are too much. Light tuna, which is darker than albacore and can be a mix of tuna types, is lower in mercury and is not subject to the recommendation.

The FDA has not set recommended limits for older children and other adults, but its general limit for human consumption is 1 ppm of methyl mercury a week.

Some mercury in the environment — exactly how much is a matter of great debate — occurs naturally. But most scientists, as well as the EPA, say most environmental mercury comes from either digging it up for industrial uses, using it in mining or burning mercurycoal.

Since the 15th century, mercury in the environment has increased 200% to 500%, says Elsie Sunderland, an EPA scientist.

Today, one of the largest sources is burning coal. The EPA estimated in 1998 that U.S. coal- 0 red power plants emit about 50 tons of mercury a year into the atmosphere. The food chain

Once up in smoke, mercury can take any number of forms; in almost all of them, it wafts around the globe, slowly settling in a process called atmospheric transport and deposition.

A small portion that falls on water is eaten by bacteria and undergoes a chemical reaction that turns it into a very toxic form of the element called methyl mercury.

Inorganic mercury, the liquid kind found in old- style thermometers, is excreted rapidly by the body so it takes relatively high doses to cause serious problems. But methyl mercury binds very tightly to muscle tissue and is much more toxic, Sunderland says.

That means with each step up the food chain, the amount of methyl mercury grows. The tiny plankton are eaten by smaller 0 sh that are eaten by medium- size 0 sh that are eaten by larger 0 sh, and the amount of mercury is thus biologically ampli 0 ed.

You’d have to drink 2,641 gallons of water to get the amount of mercury in a 3.5 ounce piece of shark or sword0 sh, Sunderland says.

The differences can be extreme. Government tests show that pollock, the 0 sh used to make most 0 sh sticks, has 0.06 parts per million of mercury. But in Mexican tile0 sh, which eat lots of other 0 sh, it’s 1.45 parts per million.

“Larger, older, predatory 0sh have the highest level,” Acheson says. “ Fish like salmon, which don’t consume other 0 sh, don’t have the problem.”

It’s important to remember that even forwomen and children in the high- risk category, there’s a host of species, such as cod, haddock or trout, that are healthful and so low in mercury there’s no concern at all, Acheson says.

But the government warnings are confusing and frightening enough that lots of people are walking past the 0 sh counter, to the detriment of their health, the Harvard researchers say. Exhausting the supply

For the more ecologically minded, over 0 shing is a concern.

In the USA, the problem took seed in the 1970s when the government extended jurisdictional limits out to 200 miles and began providing subsidized loans for boats and gear. The number of 0 shing vessels bloomed, says Barton Thompson, director of the Stanford Institute for the Environment.

As 0 sh such as yellowtail F ounder, Atlantic halibut and red snapper became harder to 0 nd, 0 shermen began to take advantage of new technological advances to 0 nd the 0 sh thatwere left.

Scaling back 0 shing F eets is dif 0 cult because it means taking away people’s livelihood, Thompson says. “ We have F eets that are too big for a number of our 0 sheries, and all of those 0 shermen have boats they have to pay off and families they have to feed.”

So the big question is: How can we eat the seafood that’s so good for us without damaging the environment? says George Leonard, science manager for the Seafood Watch program at Monterey Bay Aquarium.

Parts of the answer, such as mercurycontrols and better management of 0 sh stocks, are in the laps of governments.

But for the 0 sh- loving citizen, there’s good news, Leonard says. The 0 sh that carry the highest health risks also are among the most endangered, he says. “ Mercury bioaccumulates in 0 sh at the top of the food chain. And those are typically 0 sh we’ve over 0 shed, like shark, sword0 sh and marlin.”

So eating 0 sh a little further down the food chain, which have lower mercury levels, is not only good for the planet, it’s good for your health. Some of the best are cat 0 sh, Paci 0 c cod, Paci 0 c halibut, pollock, salmon, tilapia and trout, according to Seafood Watch.

The key seems to be 0 nding a way to make the messages simpler so consumers aren’t scared off because the health bene 0 ts of eating 0 sh are so real, says Bill Hogarth of the National Oceanic and Atmospheric Administration.

“ The American public needs to be educated a little more to make sure that the American consumer is aware of the issues.”

By Jeff Reinking for USA TODAY