I guess this is another reason to practice catch and release.

DNR Lake Reports

Scroll down to "Fish Consumption Guidelines". Pretty much all the BW waters are contaminated with mercury???

All lakes in the world contain mercury. It is not normally a result of direct pollution. Mercury is produced in the burning of coal for energy and is released in to the air and falls as rain. Atmospheric mercury can travel across long stretches of land and affect areas elsewhere. I personally still eat lots of fish. It is better to keep smaller fish because they have not been alive long enough to absorb the toxins. The mercury is mostly located in the fat of the fish so removing these portions like the belly meat will also reduce mercury intake. I learned most of this in my high school sports bio class. I wouldn't worry too much about it.

pretty much everything you say is what I understand from reading, but I was not aware that consumption advisories were so common in the BW. We have some consumption advisories here for some rivers and they are mostly re: bottom feeders and shellfish.

Smaller fish are better to eat not only because they are usually younger (less exposure to mercury), but because of their position in the food chain- big fish not only take on mercury from the water, but from the fish they eat, which concentrates it in them.

HMercury occurs naturally in the earth's soil, but is also present in the atmosphere from natural and man-induced sources. Degassing of the earth crust can release up to 6000 pounds of mercury into the atmosphere annually, and emissions of mercury from industrial discharges (chlorine alkali industry) and waste (coal and municipal refuse incinerators) also contribute. The primary industrial uses of mercury are in the manufacture of batteries, vapor discharge lamps, rectifiers, flourescent bulbs, switches thermometers, and industrial control instruments. The products usually end up in landfills or incinerators. Mercury also has been used as a slimacide in the pulp and paper industry, as an antifouling and mildew-proofing agent in paints and as an antifungal seed dressing. Of the existing sources of mercury, it is widely accepted that atmospheric depostion of both natural and man-induced mercury is the major contributor both in our state and nation-wide. Cycling of mercury in the environment is facilitated by the volatile nature of its metallic form and by bacterial transformation of metallic and inorganic forms to stable mercury compounds, particularly in bottom sedements. It is the stable or organic mercury (methyl-mercury) that is detected in fish tissue and is harmful to humans.

How Great is the Risk?
Advisories for cancer-causing chemicals in fish are issued when concentrations reach a risk level of 1 in 10,000. This means under a worst-case scenario, the chemicals would cause one additional case of cancer per 10,000 people eating those fish. Theoretically, each of those 10,000 people would have to eat five ounces of the fish every week for 70 years to produce that one case of cancer. Thus these advisories are targeted toward and effect a very smalllpart of tthe population of fish consumers in the state. Mercury is not a cancer risk but because of the way it reacts in the human body advisories for high mercury levels are targeted toward pregnant and nursing women, infants and children under 15. As for the cancer causing chemical advisory, mercury is also targeted toward people who consume high amounts of fish caught from advisory waterbodies. ere is what the Nebraska Game and Parks says around Mercury.

Way I see it you would have to conusme a LOT of fish to be of any concern. SunCatcher

Thank you, thank you, thank you SunCatcher. Well done. It would not surprise me if someone eventually proves that some mercury has been cycling around the system for eons. True objective science dispels myths and hysteria.

I'd just like to add the biggest risk for taking in Mercury is not cancer but damage to your nervous system or worse yet in Pregnant women or small children developemntal damage to the brain. It is a real risk from eating fish, there are documented cases in Minnesota and the rest of the U.S. but definitely not a common problem. The people I have seen get it are usually eating the larger fish and eating several meals a week during the summer. There are probably other exposure factors as well. I would guess very few if any on this site fall into this category.

If you do have children or preganant women along you should take the lake warnings very seriously. Not trying to be an alarmist but why take chances.

Tim

Fish contaminated with mercury are more affected by changes in temperature.

My group has arbitrarily settled on two meals of fish per 5 or 6 day trip that we go out. It has mostly to do with liking variety of food on the trip. A side bonus is less exposure to any possible contaminants, especially when my kids were young. That said, most fish, fresh caught in the BWCA are a culinary and esthetic delight. I like Fry-Magic for coating the filets.

I remember quite a few years ago the Minneapolis Startribune did an article on a dude living somewhere in NW Wisconsin who was suffering from mad-hatter's syndrome. Apparently he had been somewhat of a fish eagle all his life and ate fish most days that he caught in area lakes.