Mercury Levels in Fish Higher Than Previously Estimated

by Thom Fox

As a chef of over twenty years who has been dedicated to serving wholesome, transparently procured food, I was struck recently while reading an article about a 2010 study by www.GotMercury.org an off shoot of The Turtle Island Institute.  The study assessed the levels of Methymercury in swordfish and tuna in a  variety of restaurant and retail stores in major markets across the United States, revealing  considerably higher levels of Methymercury  than previously reported by the FDA in other tests and studies .

For a number of years it has been known that Methymercury is present in seafood. This report reiterates the risks which affect brain function, and impede development of fetuses and young children. 

As far back as March 0f 2004 the  Food and Drug Administration warned that pregnant women, nursing mothers, women who might become pregnant, and children should not eat swordfish, shark, tilefish, and king mackerel because of their high Methymercury content. The FDA also warns women and children to limit their consumption of tuna.
In March of 2006 the publication Harvard Public Health NOW wrote of the potential risks associated with consumption of certain seafood, and pointed to the difficulty in trying to balance the benefits of eating fish with the potential risks of mercury consumption.  However, they failed to produce an unambiguous guide. 

We know that Mercury is released into the air from industrial sources:  burning coal, metal smelting, and the manufacturing of chlorine products.   Wind currents carry pollutants far from the source and around the world; most often ending up in oceans, lakes and streams.   It then enters the food chain moving from the smallest creatures to the largest, accumulating in the tissues of the top ocean predator fish like swordfish, tuna and mackerel (it also shows up in polar bears and seals).

This report underscores important realities for consumers as well as chefs, restaurateurs and retailers.  The impact that certain types of industry on the environment and our food sources are not fully appreciated and those impacts still exist and are not going away anytime soon despite significant gains in the area of emissions regulation here in the United States.  The harvesting of the large pelagic fish at the top of the food chain poses considerable risks and consequences way beyond the damage to fish populations due to overfishing.   Wise choices for what we choose to purchase and serve require more consideration and examination of data and we need to be asking state, federal and international agencies to participate in the dialogue towards this end.

Chefs and consumers alike should remind ourselves that we hold a significant responsibility to ourselves, our families, our clients and the environment.  It is essential to keep in mind the important link between environmental stewardship and the food we eat.  We all need to be asking important questions about the sources of the foods we eat and serve.