Health officials warn of mercury in fish

Tuesday, June 17, 2003 | 11:05 a.m.

Nevada health and environmental officials are preparing a medical bulletin for Southern Nevada physicians to explain the dangers of eating fish that contain trace amounts of mercury, but they say there is no specific danger from eating those caught in Lake Mead.

All fish in the United States, including those in Lake Mead, contain some mercury, a naturally occurring metal washed into water from soils. The primary danger it presents is to nervous systems of unborn and young children. Western waters also contain mercury from mining.

The advisory was directed largely at store-bought fish, but the news that Lake Mead catches could contain any mercury came as a surprise to some fishermen.

"This is the first warning we've heard out there," Capt. Mike Swartz, one of 16 fishing guides on the lake, said on Monday.

"I hate for them scare people for no particular reason," said Swartz, who said he's been eating Lake Mead fish for more than 30 years and doesn't plan to stop. "It's not just Lake Mead, it's all over."

The mercury levels in Lake Mead fish are similar to those found in other parts of the Colorado River system and are generally lower than levels found in other parts of the country, Allen Biaggi, state Division of Environmental Protection administrator, said.

Mercury in water is particularly bad because bacteria in water convert mercury to methylmercury. Unlike the shiny metal found in thermometers, the compound methylmercury is fully absorbed by living tissues and becomes concentrated in each step up the food chain.

Nevada officials have been studying the issue of a mercury consumption advisory for Lake Mead fish for more than a year, Biaggi said. In July 1999 preliminary findings from studies of fish at the lake found trace amounts, but no dangerous levels of the metal.

Biaggi said the level of mercury in catfish, striped bass and carp in Lake Mead is low.

"The bottom line is the fish are OK to eat," he said.

The medical advisory would allow physicians to explain any risks from eating more than six to eight ounces of fish per week from the lake to pregnant women.

Biaggi said the bulletin was devised simply as a reminder of a federal advisory that was made years ago to health-care professionals about the potential risks of mercury in fish, whether it's bought in a supermarket or caught.

The national recommendation states that pregnant women, nursing mothers and young children should not eat shark, swordfish, king mackerel or tilefish. Those people should limit their consumption of other fish to 12 ounces a week.

The Food and Drug Administration guidelines on mercury were tightened by the Environmental Protection Agency over two years ago.

Forty states, including Nevada, warn the public to limit their intake of sport fish caught in thousands of lakes and streams because of mercury pollution. Nevada is the leading mercury producer among the states because of its mining industry.

The only Nevada body of water that carries a warning against eating fish due to mercury levels is the Carson River below Dayton. During the late 1800s gold mills dumped an estimated 7,500 tons of mercury in the river.

The concentrate of mercury in the Lake Mead fish is no greater than in Lake Powell or Lake Mohave and, in fact, is lower than fish found in the northeast part of the United States, he said.

State officials have not set a date for the release of the medical bulletin, Biaggi said.

The news didn't seem to change any minds among fishermen on the lake Monday.

"Everybody I take out on the lake wants to know if they're good to eat," master fisherman Jim Goff said Monday. "That's probably the second question they ask: 'Are these fish safe to eat?'

"I tell them I've been eating them 50 years myself."

Swartz added, "I know a lot of healthy people who eat them a lot."

Once the fact that perchlorate from rocket fuel is in the water appeared in the news, Goff said, people became much more cautious.

Goff said he takes about 150 chartered fishing trips onto the lake a year. About 1 million stripers are caught in the lake annually, he said.

"The charter this morning had 44 stripers by 10 o'clock this morning," Goff said. There's a limit of 20 fish per person and three people were on the boat.

"The people were happy, said they were going to have a neighborhood fish fry," he said.