Mercury levels high in fish tests

Health Department issues advisory for Lake Ouachita

Gerald Bryant of Hot Springs, Ark., fishes on Lake Ouachita at the Joplin Use Area Monday, August 11, 2014. (The Sentinel-Record/Richard Rasmussen)
Gerald Bryant of Hot Springs, Ark., fishes on Lake Ouachita at the Joplin Use Area Monday, August 11, 2014. (The Sentinel-Record/Richard Rasmussen)

The Arkansas Department of Health on Monday issued a fish-consumption advisory for Lake Ouachita after a number of fish recently tested positive for higher-than-normal levels of mercury.

Occasional fish consumers, such as vacationers and sport anglers, face little risk, and there is no risk of mercury contamination for boaters or swimmers, Health Department officials said.

Fish recently tested in Lake Ouachita showed mercury levels slightly above 1 part per million, according to the Health Department. Fish that test above that threshold can prompt a fish-consumption advisory.

The Health Department also stressed that Lake Ouachita's water supplies are not affected by the advisory. There also haven't been any reported cases of mercury poisoning in the state, officials said.

"Lake Ouachita is an excellent source for drinking water ... this advisory is specific for mercury in fish and not the water," a Health Department news release said. "The food chain build-up of mercury is unrelated to the lake water quality. In fact, water supplies obtained from Lake Ouachita are regularly and routinely tested and meet all safe drinking water act standards."

At 40,000 acres, Lake Ouachita is one of the most popular recreational lakes in the state and is currently at its peak visitation season. Last month, Lake Ouachita State Park hosted more than 238,000 visitors from throughout Arkansas and neighboring states, park Superintendent Lee Howard said.

Howard and other park officials spent Monday afternoon informing visitors about the mercury warning by printing out fliers and making signs. He said news of the advisory came as a surprise.

"I am still reeling from this," Howard said. "This is just a sign of the times, as we all continue to struggle with pollution issues. For now, it's a little early to know yet just how we may be affected, but we are going to get the word out and let people know. That is our first priority."

Those facing the greatest risk of mercury contamination from eating Lake Ouachita's fish are pregnant women, small children, the elderly and those who frequently eat larger fish, such as bass, according to the Health Department. Health Department officials said people in those high-risk groups shouldn't eat largemouth bass that are 13 inches or longer, white bass that are 13 inches or longer or striped bass that are 25 inches or longer.

The general public shouldn't eat more than two meals per month of largemouth bass that are 13 inches or longer, white bass that are 13 inches or longer or striped bass that are 25 inches or longer from the lake, officials said.

Health Department officials work in conjunction with the Arkansas Game and Fish Commission and the Arkansas Department of Environmental Quality to determine whether a body of water contains potentially harmful levels of mercury.

Including Lake Ouachita, there are 20 bodies of water -- including smaller lakes, rivers and bayous -- in Arkansas currently under mercury advisories.

Mercury occurs naturally in the environment and is found in varying concentrations in soils and sediments throughout Arkansas. Cinnabar, a natural, solid form of mercury, occurs as reddish veins in or near volcanic rocks.

Land near and surrounding Lake Ouachita contains deposits of cinnabar because of mining and exploration for the metal in the area.

According to the Health Department, "once mercury has entered a lake or stream, it is readily taken up by bacteria found in sediments. Mercury can build up in tissue of insects as they graze on these bacteria.

"When these insects are eaten by predators and these predators are, in turn, eaten by even larger predators, the mercury concentration increases every step, all the way up the food chain to top predators, such as largemouth bass or striped bass."

Charlie Greene, who operates the Lake Ouachita One Stop Fishing Shop near the lake, said he hasn't heard any fishermen talking about the mercury advisory and doesn't expect to. He said most people "take these kinds of things in stride."

Greene added, "It's such a large lake that if you are affected by it, it would be a small chance."

State Desk on 08/12/2014

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