Glenville latest lake confirmed for walleye mercury contamination
A new health advisory was issued this month warning people about mercury levels in walleye fish in Lake Glenville. This is not exactly news.
“As an obligate piscivore — that is, fish that feed almost exclusively on smaller fish — this species is very prone to mercury bioaccumulation,” explained Susan Massengale, public information officer with the N.C. Department of Environment and Natural Resources.
Mercury occurs naturally in low levels in rocks, water and soil. It is also created when fossil fuels — coal, oil, natural gas — are burned, and during some manufacturing processes. Once emitted into the air, the mercury settles back onto land and into water. It’s a global problem.
Since 2008, there has been a statewide fish consumption advisory in place warning the public about high levels of mercury in bass. It’s been fairly safe to assume that if bass are high in mercury, so are other higher-up-in-the-food-chain fish, like walleye.
But, now, the assumption has been verified in Lake Glenville.
“By request from N.C. Wildlife Resource Commission, we analyzed 20 walleye from Glenville Lake that were collected in 2013,” explained Massengale. “Mercury levels turned out to be high in almost all 20 samples.”
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This is not unique to Lake Glenville. It’s just a matter of being tested. The state Wildlife Resource Commission routinely collects samples of fish and routinely requests DENR to test walleye samples for mercury.
In each lake where walleye are tested — be it Fontana or Santeetlah or Gaston — it is repeatedly confirmed that the fish are too high in mercury to be considered safe. It is advised that women of childbearing age and children under the age of 15 not eat the fish, and everyone else is advised to limit their consumption to one meal per week of fish high in mercury content.
Fisherman Leonard Winchester found out in 2008 that his home lake, Lake Fontana, had walleye high in mercury. This was difficult news for him to digest.
“Because I ate walleye pretty regularly,” Winchester said.
After the state tested Fontana’s walleye, Winchester went and had himself tested for mercury. The results were startling.
“It came back unbelievably high,” the fisherman said. “It came back so high I shouldn’t have been alive. Of course, that wasn’t right, because I was alive.”
Turns out, Winchester’s initial test was wrong.
“The folks in Atlanta who did the lab work screwed up my test,” Winchester said, explaining that once a corrected test was performed his mercury levels read much lower.
But still, the news concerning Fontana’s walleye was life-changing for Winchester. Prior to that, he could be found most mornings on the waters of Lake Fontana fishing for walleye. He loved the way it tasted, ate it a few times a week and hosted regular family fish fries.
Not anymore. Since word came out that the walleye were high in mercury, the fish have pretty much dropped of his menu.
“It has made a difference,” Winchester said. “Now, I probably eat walleye once a month.”
But Winchester said he knows a lot of people who still regularly eat the walleye and bass from Lake Fontana.
“I have friends who speak very highly of the bass. They like it, they eat it, their kids eat it,” he said. “I would bet that there are plenty of people with young children who don’t think anything of it.”
Winchester blames this on the state’s “poor job on disseminating this information.”
“There’s no signs up at the lake — their alibi is that it’s in the fishing regulations and on the website,” the fisherman said. “They should have consumption advisories up at the boat ramps.”
Paula Carden, Jackson County’s director of public health, said that signs will likely be placed at locations around Lake Glenville to warn people of the mercury issue.
“I think that’s one of the things that the state will advise us to do,” Carden said, adding that the state had already informed the county that it could not foot the bill for such signage. “We’ll take care of that.”
Jackson County will also be hosting a public meeting Dec. 15 in Cashiers to educate people about the fish advisory and mercury levels in Lake Glenville. Dr. Ken Rudi, a state toxicologist with the N.C. Division of Public Health, will be present to field questions from the public.
“To try to answer any questions or concerns they have,” Carden said. “We want to do our part in educating people that are concerned.”
Carden noted that such meetings sometimes receive scant attention. Unfortunately, mercury pollution is old news to many.
“Now, I think people are kind of on board with knowing that fish have mercury in them,” she said.
Want to go?
Jackson County has scheduled a public meeting for Dec. 15 to discuss the recent fish advisory issued for walleye in Lake Glenville. The advisory warns of high mercury content in walleye, and suggests women of childbearing age and children under the age of 15 not consume the fish, and that everyone else limit their consumption of walleye — and bass, which is also high in mercury — to one meal of the fish per week.
The Dec. 15 public meeting is scheduled for 6 p.m. at the Albert Carlton Cashiers Library, located at 249 Frank Allen Road in Cashiers. State toxicologist Dr. Ken Rudo will be available at the meeting to answer the public’s questions.
Mercury primer
What is mercury?
Mercury is a metal that occurs naturally at low levels in rocks, soil and water. It is also emitted when fossil fuels like coal, oil and natural gas are burned. Forest fires, some manufacturing processes and the burning of solid and medical waste also emit mercury.
What are the health impacts of mercury pollution?
Mercury primarily affects nerve cells in the brain and spinal cord. Unborn babies and young children are especially susceptible. The more mercury that gets into a person’s body, the longer the exposure and the younger the person, the more severe the effects will be.
Mercury is especially harmful to a developing brain. It can interfere with how nerve cells move into position as the brain develops, resulting in abnormal development. Prenatal exposure can affect the way children think, learn and problem-solve.
Much higher doses of mercury are harmful to adults. Early signs of mercury poisoning include tingling or numbness of the lips, tongue, fingers or toes; fatigue; and blurred vision.
How does mercury get into fish?
After mercury pollution is emitted into the air, it then falls back down into water and onto land, where it washes into water bodies. Once in the water, bacteria can change mercury into methylmercury, which is absorbed by tiny aquatic organisms. When fresh water and ocean fish eat these organisms, the mercury begins to build up in their bodies. Mercury then makes its way up the food chain, with larger fish eating smaller fish, and builds up in the tissue of larger fish. Because it binds to the protein in fish muscles, mercury cannot be removed by cooking or cleaning the fish.
Can we still eat the fish?
Larger fish, in both fresh and salt water environments — like bass or tuna — have been found to have unsafe levels of mercury. As a result, it is recommended that people limit their consumption of such fish.
In North Carolina, officials advise that women of childbearing age and children under the age of 15 do not eat fish with high levels of mercury. For everyone else, it is recommended that not more than one meal per week of such fish be eaten.
The U.S. Environmental Protection Agency offers similar guidelines. But the agency is also stressing the importance — for children, pregnant women and everyone else — of eating varieties of fish found to have lower levels of mercury. In June, the EPA released a draft of updated advice concerning fish consumption. The agency decided to update its advice — stressing the importance of fish in one’s diet — because it found that women were limiting or avoiding fish altogether during pregnancy, and also not feeding it to their children, for fear of mercury contamination.
For a list of fish commonly consumed, as well as their corresponding mercury levels, visit www.fda.gov/food/foodborneillnesscontaminants/metals/ucm115644.htm.
Source: North Carolina Division of Public Health and the U.S. Environmental Protection Agency
