Natural Resources Protective Association: Protecting the marine environment since 1977

Mercury in the Lakes

When the state starting warning the public last year that the walleye in Tupper Lake might be contaminated with mercury, Sandra Strader was not pleased. She felt the lake and the community had been stigmatized.

“I was shocked,” said Strader, the mayor of Tupper Lake village. “I had visions of people saying, ‘We’re not going to fish there. They’ve got mercury in the fish.’”

As it turned out, her fears were unfounded: More than 1,000 people participated in the annual fishing derby on Tupper Lake in June—the biggest turnout in its four-year history. Nor has Strader seen any evidence since then that the mercury advisory is scaring away anglers. “We’re still selling a lot of fishing licenses here,” she said.

Yet the question remains: Why Tupper Lake?

Actually, Tupper is not alone. As of last year, the state Department of Health (DOH) had issued mercury advisories for 19 other lakes in the Adirondack Park. Yet, these represent less than 1% of the region’s 3,000 lakes.

So the question becomes: Why just these lakes?

The short answer is not that the other lakes are free of mercury, but that the vast majority of them have not been tested. Scientists agree that many more Adirondack lakes—perhaps hundreds more—harbor fish with high levels of mercury. This is not surprising inasmuch as most of the mercury pollution falls from the sky: Like acid rain, it comes, in large measure, from coal-fired power plants. That’s one reason regions hard hit by acid rain, such as the Adirondacks, suffer from mercury pollution as well.

The mercury emitted by the utilities and other sources can stay in the atmosphere for days, weeks, even months. When it falls to earth, bacteria convert it to methylmercury, an organic toxin that can be absorbed by muscle tissue. Methylmercury moves up the food chain and tends to accumulate in large predator fish such as walleye, bass and yellow perch. Generally, the bigger the fish, the more contaminated it is.

Critics say DOH’s fish advisory misleads the public into thinking that all the fish in Adirondack lakes not on the agency’s list are free of mercury and thus safe to eat.


The state Department of Health has issued mercury advisories for 20 lakes in the Adirondacks. DOH recommends that women of childbearing age, infants, and children under 15 not eat any fish from these waters. Others are asked to limit their consumption of certain fish, following the guidelines below.*



Dr. David Carpenter, director of the Institute for Health and the Environment at the University at Albany, contends that the state should issue a mercury advisory for all waterbodies, excluding only those known to be uncontaminated. “You can assume that mercury is being deposited in all the waters in the state,” he said. “To have advisories only on the waters that you happened to have tested is putting your head in the sand.”

Carpenter believes that some states, including New York, have been reluctant to issue blanket advisories out of fear that it would cut into fishing tourism and sales of fishing licenses. “States are trying to balance their tourism dollars against the health of the people,” he said, “and that should not be a consideration.”

David Higby of Environmental Advocates, headquartered in Albany, argues that DOH’s policy not only puts anglers at risk, but by downplaying the mercury threat it also diminishes public demand for controlling mercury pollution at the source.

“Democracy does work,” Higby said. “If the fish-eating public really understood how dangerous mercury is, how widespread it is in the environment and how prevalent it is in fish, then something would get done about it.”

The Bush administration is locked in a debate with environmentalists over how to regulate mercury emissions from power plants. The U.S. Environmental Protection Agency (EPA) proposes to reduce the utilities’ emissions from 48 tons—about 40% of the nationwide total—to 15 tons by 2018. In contrast, groups such as Environmental Defense and the Natural Resources Defense Council contend that existing technology would enable utilities to cut their emissions to 5 tons in three years.



Photo Carl Heilman

Children under 15 are warned not to eat any fish from lakes contaminated with mercury.

Mercury is a potent poison that, in high concentrations, can damage the brain, kidneys or nervous system. Humans are exposed primarily through consuming fish—either commercial fish, such as tuna and swordfish, or sport fish caught in polluted lakes and streams. A study by the U.S. Centers for Disease Control found that 8% of American women of childbearing age have levels of mercury in their blood that exceed the federal health standard—a troublesome statistic inasmuch as experts believe that fetuses are the most endangered by mercury.

But Thomas Sinks, an epidemiologist with the Centers for Disease Control, said the risks must be weighed against the benefits of eating fish (a high-protein, low-fat food). “We don’t want people to stop eating fish,” Sinks said. “We do want people to be aware of the advisories on eating fish.”

Sinks also said the health standard referred to in the study errs on the side of caution. In fact, he said, all the women tested had mercury concentrations well below the level at which harmful effects can be detected.

The EPA allows each state to draft its own fish advisories, but the agency issued guidance four years ago on the amount of contaminated fish that can be safely consumed. As the following table shows, the maximum number of meals recommended varies with the level of mercury in the fish, which is measured in parts per million (ppm). The EPA guidelines are aimed only at the subpopulations most at risk: pregnant women, nursing mothers, women who may become pregnant, and young children.

Mercury concentrationsMeals/month
0.1—0.25 ppm4
0.25—0.3 ppm3
0.3—0.5 ppm2
0.3—0.5 ppm2
0.5—1 ppm1
1—2 ppm1 every 2 months
Above 2 ppmNone

More than a dozen states, including all of the New England states, have issued blanket advisories, of one sort or another, for mercury. Maine, for example, says those in the at-risk populations should eat no fish caught in the state’s inland waters, except for brook trout and landlocked salmon. Vermont offers different advice for different species: Those in the risk groups are told they should eat no walleye, for instance, but they may eat one meal of smallmouth bass a month.

Mercury is not the only pollutant found in the New York waters. Others include PCBs, DDT, Mirex and cadmium. Because of this, DOH has issued a general advisory that no one should eat more than one meal a week of freshwater fish from the state’s lakes and rivers. But if a lake is contaminated with mercury, the guidance is much stricter: Women of childbearing age and children under 15 are advised not to consume any of the fish. Older women and adult males should eat at most one meal a month of mercury-contaminated fish.

Given that some untested lakes are contaminated with mercury, this means a pregnant woman who fishes in such a lake could follow DOH’s advice and still eat up to four meals a month of tainted fish. That is four times as many as an adult male would eat if he fished in a lake known to be contaminated and followed DOH’s guidelines.

The amount of mercury ingested in four meals would be small—so small, in fact, that any harmful effects probably would be unobservable in either the fetus or the mother. Nevertheless, studies suggest that a child exposed to mercury in utero may end up with a slightly lower IQ. Since mercury can linger in the body for months, Dr. Carpenter recommends that women stop eating fish from all New York waters a year before pregnancy. “Women need to be aware that the intelligence of their child will be reduced if they have high levels of mercury in their bodies,” he said.

Moreover, Carpenter and others contend that DOH’s “action level” for mercury is far too lax. DOH does not include a lake in its advisory unless fish are found with contamination above 1 ppm. The critics say the action level should be set at 0.5 ppm or 0.3 ppm. Adopting a tougher criterion would mean that many more lakes would fail to meet it.

Michael Bender, director of the Mercury Policy Project, an environmental group based in Vermont, categorizes concentrations over 0.3 ppm as “high,” those over 0.5 ppm as “very high,” and those over 1 ppm as “off the charts.” He called New York’s action level “totally ridiculous” and said most states, including those in New England, have adopted more stringent standards.

Under DOH policy, a lake containing fish with 0.5 to 1 ppm of mercury is not considered contaminated. So a woman following the state’s general advisory could consume up to four fish meals from such a lake—four times as many as recommended by EPA.
Yet EPA’s message is not always clear cut. In addition to the guidelines issued four years ago, EPA and the Food and Drug Administration tell the public that it’s OK to eat up to one meal a week of fish taken from waters that lack local mercury advisories—essentially, the same advice contained in the state’s general advisory. “It serves as a backstop in absence of local information,” said Jim Pendergast, who oversees EPA’s fish advisories.

Because EPA defers to the states in such matters, it sticks to the one-meal-a-week recommendation even if, as in New York’s case, the state’s own testing reveals levels of mercury in fish that suggest less-frequent meals would be warranted.

Bender says the federal government’s default recommendation is not strict enough. He argues that one meal a week is too many if the fish contain more than 0.3 ppm of mercury. “It was a political call, not a scientific one,” he said.

The Adirondack Park has many lakes with fish whose contamination levels fall between 0.3 and 1 ppm. In fact, Charles Driscoll, an environmental scientist who teaches at Syracuse University, believes nearly every lake in the Park has some fish above 0.3 ppm. When he analyzed yellow perch from 26 Adirondack lakes, however, he looked for higher levels of mercury. The results: He caught at least one perch with 0.5 ppm of mercury in 87% of the lakes and at least one with 1 ppm in 56% of the lakes. “Where we test for mercury we inevitably find high values,” Driscoll said.

In another study, the Biodiversity Research Institute detected “high” or “extra high” levels of mercury in the blood of 17% of Adirondack loons tested. Nina Schoch, one of the researchers, said the loons pick up mercury by consuming fish. According to other studies, loons with mercury poisoning have low reproduction rates and may be vulnerable to disease.

“We’re looking at loons as an indicator of environmental health,” Schoch said. “If loons have a lot of mercury in their bodies, then it would be expected that other top predators in the aquatic ecosystem, including predatory fish, will have high mercury levels. If people eat a lot of fish of the wrong type, they could be affected, too.”

The Department of Environmental Conservation (DEC) also has found fish with more than 0.5 ppm of mercury in numerous waterbodies not on the advisory list. Through 2002, DEC had tested selected species of fish in 73 Adirondack lakes over three decades. Of these, 20 ended up on the advisory list. The Explorer examined the data from 43 of the other Adirondack lakes and found that 31—more than 70%—had at least one fish tested by DEC with mercury levels above 0.5 ppm. In nine of these lakes, in fact, DEC caught fish that exceeded the state’s action level of 1 ppm. They include:

• Forked Lake, the site of a state campground. In 1998, DEC caught nine smallmouth bass and discovered three of them had mercury levels above 1 ppm. Five others had levels between 0.5 and 1 ppm. The last had 0.4 ppm. DEC also caught a largemouth bass with 1.02 ppm of mercury.

• Sagamore Lake, near Great Camp Sagamore, a National Historic Landmark now used as a lodge and educational retreat.
In 1992, DEC tested 29 yellow perch. One had a mercury level above 1 ppm. Thirteen others had levels ranging from 0.52 to 0.91 ppm.

• Lake George, the largest lake wholly in the Adirondack Park—and the most popular. Back in 1970, DEC tested 13 lake trout and found all had levels above 1 ppm. The highest reading was 1.8 ppm.

In later years, none of the lake trout tested exceeded 1 ppm, but many had contamination levels between 0.5 and 1 ppm.
n Great Sacandaga Lake, the Park’s second-largest lake. In 1970, DEC caught seven walleye and found three had levels above 1 ppm. The contamination in three of the others was above 0.5 ppm. The last had 0.3 ppm. No walleye have been tested since, according to data provided by DEC.

DOH bases its advisories largely on DEC’s testing. Asked why the four lakes mentioned are not on the advisory list, DOH spokeswoman Claire Pospisil said the agency may add Forked Lake to the list this year, but the data from Lake George and Great Sacandaga Lake were too old to justify an advisory. She didn’t have any information on Sagamore Lake.

Pospisil argues that the advisories issued by DOH are adequate to protect public health. (In one respect, DOH’s guidelines are stricter than EPA’s: Once the state places a lake on its mercury list, it advises pregnant women and children to eat no fish from that water.) She also said the department opposes a blanket advisory for the Park or for the state. “The Adirondacks are not homogenous with regard to mercury contamination,” she said.

Since 1970, DEC has tested, on average, about three lakes a year in the Park. At that rate, it would take more than a thousand years to test all the lakes in the region. No one expects DEC to get to them all—which some cite as another argument for a blanket advisory—but if it did, how many would make the mercury list?
The 20 lakes with mercury advisories represent 27% of the waterbodies tested. If that percentage were representative of the whole Park, then 840 lakes would make the list. But Howard Simonin, chief of DEC’s Aquatic Toxicant Research Unit, says it’s not that simple. Many backcountry ponds contain mostly brook trout and small fish that do not accumulate large amounts of mercury, and many others are fishless. He estimates that there is a mercury problem in only 5% to 10% of Adirondack lakes—which translates into 150 to 300.

Simonin’s estimate, however, is based on DOH’s action level of 1 ppm. If DOH adopted the stricter criterion of 0.5 ppm or 0.3 ppm, he said, “a much larger percentage” of the lakes would be deemed contaminated. Given the frequency of this level of contamination found by DEC and by Driscoll, it’s not unreasonable to expect the number of lakes on the advisory would approach or exceed 1,000.

Is DOH minimizing the mercury threat to avoid scaring away anglers and other tourists? When asked this, Pospisil replied that the point of the advisories is to give anglers information. She refused, however, to issue a flat-out denial that the state is playing down the threat for economic reasons, insisting she had already answered the question. Pressed for a yes or no answer, she said she had to get off the phone. “It was good talking to you,” she said. “I look forward to seeing your publication.”

Others are skeptical of the motives behind the DOH policy, especially since fishing is one of the Park’s biggest attractions. Linda Greer, a scientist at the Natural Resources Defense Council, said she has seen disagreements in other states between tourism and health officials when a blanket mercury advisory is proposed. The reasons are obvious: “For a state to say you can’t eat the fish caught in any of our lakes—it doesn’t sound like a place you’d like to take your next vacation.”

Wally John, executive director of the New York State Conservation Council, which represents anglers and other sportsmen, said he does not believe the state is downplaying the threat. He also said his organization has not pressured the state to refrain from imposing a blanket advisory on mercury. He added, however, that he does not think a statewide advisory is necessary. “The existing warnings are broad enough to cover the situation,” John said. “Everybody’s aware that there are problems if you eat too much fish.”

Another criticism of the DOH fish advisory is that it’s confusing. The agency’s guidelines vary not only from species to species and lake to lake, but also with the size of the fish. Consider the advice to an adult male regarding the consumption of yellow perch from the following three lakes:

• Big Moose Lake. If the perch is more than 9 inches long, you should eat only one meal a month. There is no mercury advisory for perch smaller than 9 inches.

• Lower Sister Lake. Here you can eat the perch up 10 inches long, even though this lake is less than 2€ miles from Big Moose. In this case, however, you are told to eat none of the larger perch. Again, there is no mercury advisory for smaller perch.

• Meacham Lake. Here, you should not eat any perch greater than 12 inches. But in this case you also are warned to eat only one meal a month of smaller perch.

DOH contends that the difference in advisories is warranted by testing results. But David Higby of Environmental Advocates questions whether the limited testing done by the state (most of the Adirondack lakes have been sampled only once or twice) can justify such fine distinctions. In any case, he said, the regulations are too arcane to be effective. “Anybody who tries to read the fishing advisories just laughs them off,” he said.

Andrew Smith, the state toxicologist in Maine, agrees that health advice for the public ought to be easy to communicate and understand. That’s one reason Maine opted for a statewide mercury advisory that applies to all waterbodies. He also said that his state wanted to err on the side of caution in protecting the public, even if the threat of mercury is small.

Smith said scientific risk assessments for mercury are based largely on studies in the Faroe Islands in the North Atlantic and the Seychelles Islands in the Indian Ocean. In both places, the residents regard seafood as a staple and are often exposed to 10 times as much mercury as is the typical American. Nevertheless, Smith said the effects of mercury among the islanders are so subtle that they can be detected only on a broad scale. For instance, a study group of 100 children from the islands may score, on average, a few points lower on intelligence tests than other children do.

“For any individual, it’s virtually impossible to diagnose a child and say, ‘Aha! You had too much mercury in fish,’” said Smith, who holds a Ph.D. in environmental health from Harvard University.

Of course, the risk to an angler who eats a fish or two from an Adirondack lake is even smaller. And these days, more and more recreational anglers are throwing their fish back. “The vast majority of anglers today are catch-and-release fishermen,” said Adirondack guide Joe Hackett. “I would be more concerned about the local people in the Adirondacks who hunt and fish to put food on the table. They aren’t likely to even read the advisories. They’re not concerned about mercury. They’re worried about where their next meal is coming from.”

Nevertheless, Hackett contends the threat posed by mercury does not justify a state-wide or Parkwide advisory. “You have to weigh the health benefits against the tourism benefits,” he said. “If you have a blanket ban, is that going to scare off some families who come here to fish?”

Others argue that New York, like the New England states, should err on the side of caution. Peter A. A. Berle, a former DEC commissioner, counts himself among those who favor a statewide or Parkwide advisory for mercury. “That’s far better than specifying that some lakes are polluted and leaving it to the fisherman to assume the rest are OK,” he said.
“Speaking as a fisherman,” Berle added, “I think every fisherman ought to know whenever fishing public waters whether the fish pose a health risk. That ought to be a universal principle.”

EPA Mercury Proposal Debated
The U.S. Environmental Protection Agency is proposing to cut mercury emissions from power plants nearly 30% by 2007 and 70% by 2018. Since utilities account for 40% of these emissions nationwide, the regulations would lead to a substantial decrease in pollution.
Environmentalists, however, say the cuts are neither deep enough nor fast enough. The Natural Resources Defense Council (NRDC) plans to sue if the regulations are adopted.

NRDC lawyer John Devine and other critics contend that utilities could cut their mercury emissions by 90% over three years if forced to install what’s known, in the jargon of the Clean Air Act, as maximum achievable control technology, or MACT.

In December 2000, a month before President Bush took office, the EPA ruled that utilities should be required to meet the MACT standard. Late last year, however, the agency proposed to abandon this standard in favor of another approach to controlling mercury emissions.

EPA spokeswoman Cynthia Bergman contends that the new approach will result in deeper pollution cuts than would sticking to the MACT standard.

Part of the dispute is over what the maximum achievable control technology is. Environmental activists argue that pollution controls installed at medical-waste and municipal trash incinerators have cut mercury emissions by 90% and utilities can do the same. Bergman, however, said it hasn’t been proven that the technology used by these smaller facilities would work at power plants.
“We have to develop a proposal that will work for the entire industry using the technology we have now,” she said.

EPA instead proposes to regulate mercury emissions through a cap-and-trade program. Under such a program, utilities that manage to reduce their emissions below federal targets will earn pollution credits that can be sold to dirtier plants. The idea is to provide utilities with an incentive to find innovative ways to reduce their pollution. EPA expects emerging technologies will soon surpass those used by utilities today.

Although environmentalists generally support the cap-and-trade scheme for cutting acid-rain pollution, they oppose it for mercury. Mercury vapor is heavier than sulfur dioxide and nitrogen oxides, which are the main precursors of acid rain. Consequently, much of the mercury emitted by a power plant falls relatively close to the plant. Environmentalists say allowing utilities to buy pollution credits rather than forcing them to clean up will perpetuate “hot spots” where people are exposed to high levels of the toxic metal.

In a related action, EPA is proposing regulations to reduce utilities’ emissions of acid-rain pollution. It’s expected that technological controls for sulfur dioxide and nitrogen oxides will reduce mercury emissions as well. EPA sees this “co-benefit” as a plus, but critics see it as an excuse for utilities to do little or nothing about mercury for years to come.

“If EPA required reductions of no more than 30% [in mercury emissions], then most coal-fired power plants would not have to do anything else to meet the new mercury limit,” NRDC says on its Web site.

And the Union of Concerned Scientists says in a recent report, Scientific Integrity in Policymaking, that the utilities helped write the mercury proposal. It contains, the report notes, “no fewer than 12 paragraphs lifted, sometimes verbatim, from a legal document prepared by industry lawyers.”

—Phil Brown

Reprinted From:
Adirondack Explorer Magazine

Send your comments to:

Rick Fenton, NYSDEC, Region 5, P.O. Box 1316, Northville, NY 12134 or phone him at (518) 863-4545. You also can e-mail suggestions on any tract of state land in Region 5 (the eastern two-thirds of the Park) to