5/10/2010 High Plains Lake: Mercury mystery (Posted By Mike Mecke)
High level of element in Lake Alan Henry baffles scientists
By Elliott Blackburn | AVALANCHE-JOURNAL
Monday, April 26, 2010
Story last updated at 4/26/2010 – 12:11 am
High West Texas levels of a natural toxin have researchers scratching their heads.
John A. Bowersmith / Avalanche-Journal
Anglers try their luck at Lake Alan Henry in March. In February, health warnings were issued because of high concentrationsof mercury, an innocuous element which can turn toxic in water. Biologists and other researchers who study the chemical said they don’t know why mercury levels are so high.
Concentrations of mercury, an innocuous element that can turn toxic in water and prompted health warnings at a Lubbock fishing spot in February, have stumped biologists and other researchers who study the element. Mercury levels in fish do not affect drinking water quality.
Researchers who spoke with The Avalanche-Journal couldn’t tie the problem to any of the dozens of possible sources of the pollutant tainting fish at Lake Alan Henry.
“The truth is, we don’t know, and it’s a mystery as to why it would be
elevated in that region,” said Matthew Chumchal, an assistant professor of biology at Texas Christian University.
Most mercury floats through the atmosphere in an elemental, low-toxic form, belched into the air by coal-fired power plants, forest fires and even volcanic blasts. It can roam for years, and, in some forms, over thousands of kilometers before becoming mixed up with rain or settling into waterways.
The company the element keeps when it reaches lakes and rivers causes most of the trouble, Chumchal said.
Common, water-borne bacteria methylates mercury. Methylmercury does a better job of sticking to the tissue of fish, among other things, and poses the threats state health officials warned of in February.
Methylmercury levels found as early as 2005 in largemouth bass at Lake Alan Henry exceeded state health department levels. Further testing on fish captured in 2008 revealed mercury levels considered a danger to human health.
“As long as it’s straight mercury, it’s not a problem,” said Charlie Munger, a Canyon-based Texas Parks and Wildlife biologist. “When it’s methylated by bacteria and things, then it’s taken up into the food chain.”
State health officials warned in early February against eating more than two eight-ounce meals of fish from the lake in a month.
High levels of the pollutant can damage the brain, kidneys and developing fetuses, making pregnant women especially vulnerable to the pollutant, Chumchal said.
State testing did not find dangerous levels of any other carcinogens, pesticides or other hazardous materials.
The problems repeat mercury levels found at Lake Meredith. Researchers couldn’t put a finger on why West Texas would have such consistent problems, but had a few clues.
Coal-fired electric plants supply most of the mercury in the atmosphere. Southwestern Public Service Company stacks at Harrington and Tolk stations spew the element as a byproduct of the cheap energy source that accounts for more than half the electricity powering Panhandle homes.
But mercury can spend years in the atmosphere and travel the globe, so sitting so close to power plants doesn’t imply high mercury levels, researchers said. Asian plants launched more than half the man-made mercury floating around the globe, compared to the 3 percent of man-made emissions traced to the United States, based on studies published over the past 15 years.
Panhandle geology may encourage the bacteria turning the mercury into its more dangerous form, Munger said. More acidic lake water also tends to have more mercury problems. Or it could be a case of growing pains for Lake Alan Henry, Chumchal said; new lakes tend to have mercury problems.
“The younger the reservoir, the more methylmercury you see in fish,” Chumchal said. “The age of Alan Henry could, potentially, be a factor.”
Even if researchers had a smoking methyl gun, tracing it in the Panhandle could pose problems. There just wasn’t enough data in West Texas, Chumchal said.
The Texas Commission on Environmental Quality requires permits for mercury releases into the air and water, but air-testing was difficult, spokesman Terry Clawson said in an e-mailed response to questions. New facilities must have monitoring equipment – older facilities, like Tolk and Harrington, estimate mercury based on the fuel they use. Most state testing was done just as it was at Alan Henry – on fish, far removed from its source.
Researchers have more than a decade of tracking in eastern and western United States provided by a series of voluntarily installed equipment monitored by the Mercury Deposition Network.
Their maps show a blank white sandbar between two brown ponds of data traveling up from West Texas into the Dakotas. The $11,000 monitoring stations don’t exist in West Texas; a Fort Worth site recently shut down, program coordinator David Gay said.
“Texas is a tough place to break into,” Gay said. “It’s a huge hole in our network.”
Anglers remained more interested in what they could snare from the water on the end of a line than what might line the muscles of their catch.
Fishing tournaments at the future water supply and current bass fishing gem Lake Alan Henry continued undeterred by warnings against eating fish caught from the reservoir out
Munger, the Canyon-based biologist, said mercury wouldn’t stunt the growth of record-breaking lunkers, a main concern for fisherman trying to set lake records.
Sport fisherman tend to catch and release their bass, anyway, to encourage larger fish and the lure of bigger lake records, said Stacy Miller, tournament director of the Hub City West Texas Anglers.
He worried a little for families who may eat fish from the lake, but didn’t eat much himself, he said.
“It does concern us, but like I said, we don’t eat a whole lot of them,” Miller said.
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