By Robert Lucke
Montana Fish, Wildlife and Parks in Havre has several pamphlets that talk about such things as mercury levels in fish. One thing that all of them stress is that mercury levels do not have to be caused by pollution. They are natural in some levels in some fisheries.
"Mercury is widespread in the environment and can be found in low concentrations in most soils and rocks. These naturally occurring deposits are the most probable cause for elevated levels of mercury in fish in Montana. Mercury accumulates in food chains. It may take months or years of regularly eating contaminated fish to accumulate levels which are a health concern. Although mercury can damage an adult's nervous system, its most severe effects are on developing fetuses in pregnant women. This is why it is especially important that pregnant women, nursing mothers, women who may become pregnant in the next several years, and children under age six follow the recommendations in this advisory. The first symptoms of poisoning include uncoordination and a burning or tingling sensation in the fingers and toes. As mercury levels increase, your ability to walk, talk, see and hear may all be affected in subtle ways. Meal guidelines from the Montana Department of Public Health and Human Services are intended to protect against the first symptoms of mercury poisoning."
General guidelines from the Montana Department of Public Health and Human Services include: keep smaller fish for eating, eat smaller meals when you eat big fish and eat them less often. Eat fish that are less contaminated, clean and cook your fish properly, and high risk individuals, like young children and nursing mothers, should be especially concerned about fish-eating habits.
Then there are ever-changing federal guidelines for mercury.
Havre FWP fish biologist, Kent Gilge, tells of a near problem with mercury at Fort Peck.
"Levels switch back and forth. In Fort Peck during the 1970s, levels were well beyond FDA safety standards," Gilge recalled. "How do you tell people that. It went on for two weeks and within that two weeks, FDA decided that the rate was too restrictive, so overnight in all Fort Peck fish, we were well below the safety limits."
The bottom line seems to be not to eat large fish where there are mercury problems, particularly if you are in the groups that can be harmed by increasing mercury levels.
