You're right, the larger species of ocean fish have serious levels of mercury toxicity. The best website resource I could find right away is the
U.S.-based Natural Resources Defense Council's (NRDC) webpage:
The guidelines I know about so far include:
1. Avoid the top-of-foodchain fishes. Carnivores like tuna should be consumed infrequently, since the larger fishes live longer and thus accumulate
more toxins over those longer lifetimes. (I also am a tuna-lover, and I have cut back to once a month or so.)
2. Also be cautious about farmed fish ... recent reports I have seen indicate a heavy exposure of these creatures to antibiotics as well as problems
with a substandard diet (cheaper for the fish farmers that way, I guess).
3. Limit your consumption of bottom feeders (a long list here, unfortunately, such as [yes] shrimp, lobster, sole, flounder, prawns, etc.). The
toxicity problem here extends beyond mercury to greater susceptibility to ocean floor contaminants near continental coastlines.
So is there any good news? Well, I have seen two different reports from credible sources about the increased longevity of human beings who eat
sardines in their traditional diets (Mediterranean is one example). The sources I saw these reports in are subscription health newsletters, not
freebie sources. I gather that the omega-3 in these fishes (plus their youth, which qualifies them as a nontoxic source of omega-3) is the key
Also, when you visit a fresh fish market, don't bother to ask what's fresh, because the staff will always tell you that everything is fresh. The
key question to ask is:
"What came in today?"
The subject of omega-3 sources is complex, and the best and most current source of information on this topic is in the paperback book for sale on the
I have read the book myself, and while it is Not ! a quick read, it is truly authoritative. If I recall correctly, this book shows that if you want
to take omega-3 supplements, the highest sources of omega-3 are in krill oil (as in Arctic and Antarctic krill, no joke).
Finally, if you are eligible to vote, please do so, because these problems are definitely susceptible to political solutions. Wasn't there a similar
problem with mercury contamination in U.S. waters due to Nixon or Reagan administration policies? And weren't those problems largely resolved by
Good luck with your quest. Let us know if you have further questions.
[edit on 11/7/2007 by Uphill]