Fish consumption advisory issued for Lake Granby: Elevated levels of mercury
March 23, 2009
Lake Granby is one of several tested Colorado lakes to have elevated levels of mercury in fish tissue samples.
The lake has been issued a fish consumption advisory by the Colorado Department of Public Health and Environment.
Out of 33 lakes tested in 2008, Granby resulted in one of five where at least one fish met or exceeded the mercury action level of 0.5 parts per million set by the state health department.
The Colorado standard is more stringent than the federal standard at 0.3 parts per million in fish tissue.
The Lake Granby advisory targets large-sized lake trout.
It recommends that children aged 6 years or younger not consume any lake trout greater than 30 inches.
Pregnant women, nursing women and women who plan on being pregnant should limit themselves to one meal per month of lake trout larger than 30 inches. The same is recommended for the general public.
A meal is considered to be 8 ounces for adults.
“The higher up in the food chain, the more the organism may bio-accumulate the levels of mercury, but it might not be in all fish,” said Randy Hampton of the Colorado Division of Wildlife.
Hampton pointed out that the Environmental Protection Agency’s standard for commercial fish is 1 part per million, meaning store-bought tunas and swordfish can contain accepted traces of mercury.
The main source of the mercury in Colorado water bodies, states a CDPHE press release, is from the air being deposited in lakes, steams or reservoirs.
Working with the electric utility industry, over the past two years, the state health department set guidelines to dramatically reduce mercury emissions from coal-fired power plants ” 80 percent reductions for existing facilities starting in 2012, 90 percent reductions by 2018, and 90 percent reductions for new or modified facilities effective immediately.
Colorado’s requirements include installing air monitors for mercury emissions from power plants.
“These measures will serve to substantially benefit lakes, streams, aquatic species and human health by reducing the amount of mercury that ends up in our natural riparian ecosystems,” according to CDPHE statements.
The fish tissue testing is part of an ongoing five-year sampling of about 120 water bodies in Colorado.
Since 2004, more than 112 water bodies have had laboratory testing completed.
Of those, about one in five have required fish consumption advisories for mercury. Also listed are two water bodies not part of the mercury study, but were posted for other parameters: Sweitzer Lake for selenium, and Willow Springs Ponds for perchloroethylene.
Fish consumption advisories for various Colorado lakes can be found on the state’s Web site at http://www.cdphe.state.co.us/wq/fishcon/index.html.
– Tonya Bina can be reached at 887-3334 ext. 19603 or e-mail email@example.com.