In my freezer there's a hunk of halibut a friend brought from Alaska and fillets from a walleye I caught in Canada.

I live in the village of Saranac Lake, on a street named Lake, within a mile of Lower Saranac Lake, from which I'm not supposed to eat a single fish. My town is within the Adirondack Park, which contains more than 11,000 lakes and ponds, from which the state Health Department advises I eat no pike, walleye or bass.

Adirondackers, like people elsewhere, are trying to grow more of our own produce and buy food from local farms, scarce as they are on this northern granite outcrop. Unlike people elsewhere, a lot of us still hunt to fill the larder.

So it's frustrating that there's a barrier between us and the one local food that's actually abundant: fish.

The state annually stocks fingerlings here by the millions, and millions more hatch on their own. But as prevailing winds carry airborne mercury from Midwestern power plants toward the Atlantic, it falls on the Adirondacks in rain and snow, poisoning the fish.

The matter-of-fact language in the booklet issued with my fishing license -- "Fish can be good to eat and nutritious, but some fish contain chemicals that may be harmful to health" -- is as forceful as a cigarette pack warning circa 1966.

Mercury concentrates as it moves up the food chain from zooplankton, to fish, to osprey or human. It can cause brain damage in in fetuses and children, so women and kids must be especially careful.

The heavy metal is more toxic in the Adirondacks than in much of the Northeast because our bedrock lacks calcium to buffer another export of coal-fired electricity: acid rain. Mercury reacts in low pH (acidity) to produce methylmercury, an organic form that living things absorb readily.

Trout that feed on insects accumulate mercury (as do spiders, sparrows and chickadees). Walleye and species that prey mainly on other fish accumulate more. I catch trout from a lake 10 miles east, a deep one with a higher pH. Still, I wonder what harm their pink flesh holds.

As New England towns go back to the water with community-supported seafood cooperatives, the catch-and-don't-eat policy of the Adirondacks grows increasingly absurd. A generation ago, panfish were a staple of many a North Country diet, and within my own memory it was fine to go down to the lake and catch dinner. Adirondack angling is now promoted as sport, but I fish for food.

Inedible inland fish get little attention, and not just at the national level where airborne mercury must be stopped. Farmers market foodies generally don't fish, and ice fishermen (who take home the most catch) either tell me they're skeptical about government warnings or they don't bother to read them. Men -- and most anglers are men -- are advised to eat no more than four servings of freshwater fish each month, anywhere in New York; 130 New York water bodies are under more stringent advisories.

I grew up in the 1970s and 1980s in Buffalo, reeling delicious PCB-contaminated walleye out of Lake Erie, a Rust Belt water ringed by factories and farms. After 38 years of the Clean Water Act, the Health Department advises I may now eat more fish from Erie than from the Lower Saranac, a loon-song lake fringed by cedars and ferns. Mercury lingers longer in the ecosystem than PCBs, but if Lake Erie can recover then there's hope for other Northeastern waters.

Despite widely available and proven technology, power plant mercury is unregulated, floating beyond the reach of the Clean Water or Clean Air Acts. While the utilities industry has delayed regulation for two decades through lobbying and court challenges, we in the Adirondacks have watched upwind construction of more than 20 new coal-fired generators. Even if emissions were cut this year, excess mercury will remain in the soil, water and wildlife for my lifetime.

In March, the Environmental Protection Agency proposed standards to capture 91 percent of the element at the smokestack. Coal is under attack for producing greenhouse gases and toxic fly ash, and for obliterating Appalachian mountaintops. Mercury is the one thing wrong with coal that's relatively cheap and easy to fix, yet the utility company American Electric Power and coal state legislators continue to stall in hearings and in Congress. A final rule is scheduled to be adopted by November, if it's not derailed. The public comment period closes Aug. 3.

I'll never get to eat a fish from my home lake. But for the sake of Saranac -- and for the sake of a 7-year-old who loves to catch fish with me but doesn't yet understand why he can't eat them -- we can't let mercury slip by any longer.

Mary Thill writes about the environment, business, science and energy, much of it focused on the Adirondacks, where she has lived for two decades. She previously was an editor at Adirondack Life.