Foothills Water Network

Mercury in Fish

Gold Rush mercury a danger in fish, state says in Sierra warning
Associated Press - 12/16/03
By Don Thompson, staff writer

SACRAMENTO - Mercury used by Gold Rush miners is contaminating fish today, state regulators said Tuesday in their first such warning for Sierra Nevada waterways.
Most people can safely eat limited amounts of the contaminated fish, but children and women of childbearing age should be careful how much they consume, the California Environmental Protection Agency's Office of Environmental Health Hazard Assessment said. Excessive mercury levels can damage the nervous system.
The agency's fish advisory has guidelines for eating fish from Camp Far West Reservoir, Lake Combie, Lake Englebright, Rollins Reservoir, Scotts Flat Reservoir and portions of the South Yuba River, Deer Creek and Bear River in Nevada, Placer and Yuba counties, and from Black Butte, Stony Gorge and East Park reservoirs in Glenn, Tehama and Colusa counties.
Gold miners used mercury to separate gold from sand and gravel. The toxic mercury was allowed to flow into rivers and streams, where it accumulated in the soil.
Over the generations, bacteria convert the inorganic mercury to more dangerous methylmercury, which fish then eat. The department warns that the methylmercury can accumulate in fish in concentrations thousands of times greater than in the surrounding water.
The warning suggests that children and women of childbearing age not eat any bass from Camp Far West Reservoir; eat bass and catfish from the other waterways no more than once or twice a month, depending on where the fish are caught; and eat trout from Deer Creek no more than twice a month.
Adult men and women beyond their childbearing years should eat bass and catfish from the waterways no more than two to four times a month, depending where they're caught, and eat Deer Creek trout no more than four times a month, the advisory says.
For the Black Butte, Stony Gorge and East Park reservoirs, women and children should limit bass to one meal a month and catfish, carp and crappie to two meals per month. Men and older women can safely consume the fish twice as often.
ON THE NET - Office of Environmental Health Hazard Assessment: http://www.oehha.ca.gov

Mercury warnings for area waterways
Grass Valley Union - 12/17/03
By Dave Moller, staff writer
You can still eat the fish out of area streams and lakes, but state officials Tuesday said people should limit their consumption because of Gold Rush-legacy mercury levels that could harm human nervous systems.
California Environmental Protection Agency spokesman Allan Hirsch said no one has been known to die or suffer from any disease after eating Nevada County fish and that physical contact with mercury in watersheds is not a concern.
Although state and local officials have been sending out consumption warnings for mid-Sierra fish for three years, "this is final," Hirsch said. The warning was issued at various levels for:
• The South Yuba and Bear rivers
• Deer Creek
• Scotts Flat Reservoir
• Lake Englebright
• Lake Combie
• Rollins Reservoir
• Camp Far West Reservoir
The agency is especially concerned about pregnant women, who could pass mercury levels on to children, and those 17 or younger.
Affected infants could have short attention spans, language-skill deficiencies and learning disabilities, he said.
All other people with mercury poisoning from fish could get tingling in their hands, feet or mouths, Hirsch said. Higher levels could affect vision or coordination.
The official state fish advisory said children and women of childbearing age should not eat any bass at all from Camp Far West Reservoir. They should also limit their bass and channel catfish meals to one or two a month from all other bodies of water in Nevada, Placer and Yuba counties.
The at-risk group should limit meals of trout from Deer Creek to twice a month and from the Bear and Yuba rivers to four times a month, the advisory said.
All other females and adult males should limit their bass and channel catfish meals to two to four meals a month and Deer Creek trout to eight a month, the state said.
The advisory lumped Lake Englebright, Scotts Flat Reservoir, Rollins Reservoir and Lake Combie fish under general mercury guidelines of no more than 12 meals per month for adults and only four per month for children and women of childbearing age.
Hirsch said higher levels of mercury found in Deer Creek fish during a federal study in 2000 caused the tougher consumption recommendation levels for that stream. He also said trout in area streams had higher levels in most cases than lakes because stream trout tend to be natives that can soak up more mercury over time compared to lake trout, most of which are young planters.
In 2000, the federal study caused county health officials to recommend limiting their bass meal intake to only one a month and once a week for trout, blue gill, sunfish, crappie and catfish. Those officials were unavailable to reconfirm those recommendations late Tuesday.
Gold miners used mercury to separate gold from sand and gravel. The toxic mercury was allowed to flow into rivers and streams, where it accumulated in the soil.
Over the generations, bacteria convert the inorganic mercury to more dangerous methylmercury, which fish then eat. The state EPA warns that methylmercury can accumulate in fish in concentrations thousands of times greater than in the surrounding water.

The Associated Press contributed to this story. #

 

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