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Consumption advisory issued for North Island Lake walleye

FOR RELEASE: August 11, 2006
Dennis Unkenholz, South Dakota Department of Game, Fish & Parks, 773-4508
Pat Snyder, South Dakota Department of Environment & Natural Resources, 773-4729
Dave Micklos, South Dakota Department of Health, 773-4130
Consumption advisory issued for North Island Lake walleye
PIERRE - The state has issued a consumption advisory for walleye 18 inches or greater from North Island Lake in Minnehaha and McCook Counties. Recent testing of game fish in the lake 10 miles west of Colton found mercury levels exceeding 1 part per million (ppm) in walleye 18 inches and longer. Larger, older fish have more exposure to mercury contamination and thus accumulate more mercury in their flesh.
Because fish is a good source of high quality protein and other nutrients and is low in fat, it can be an important part of a balanced diet as long as consumers are aware of the consumption advisories. The Department of Health recommends that healthy adults eat no more than 7 ounces per week of the specified walleye. Children younger than 7 should eat no more than one 4-ounce meal of the fish per month. Women who plan to become pregnant, are pregnant or are breast-feeding should have no more than one 7-ounce meal of the fish per month. Seven ounces of fish is roughly the size of two decks of playing cards.
When mercury levels in fish reach 1 ppm, meals should be spaced to prevent potentially dangerous mercury accumulation. The Food and Drug Administration (FDA) has set 1 ppm as the action level for commercial fish. This action level is 10 times lower than the lowest levels associated with negative neurological effects observed in mercury poisoning incidents. The Department of Health uses the FDA action level to issue consumption information to the public. 
Fish in South Dakota lakes and rivers are tested for metals, pesticides, and PCBs. Of all the contaminants analyzed, mercury is currently the only concern; all other contaminants have been either non-detectable or found only in low concentrations.  
For a list of other consumption advisories in effect and for more information about mercury and fish and fish consumption, see the Department of Health's web site at www.state.sd.us/doh/Fish.