The South Dakota Department of Health has issued a consumption advisory for three South Dakota lakes. The consumption advisory is for potentially unhealthy levels of mercury in these waters. The lakes include and size of fish include Horshoe Lake in Day county on 18 inches or greater walleye, Cottonwood Lake in Spink county on 21 inches or greater walleye and Reid Lake in Clark County on 32 inches or greater for Northern Pike. Reid Lake also has an existing advisory for 23 inches or larger walleye. The South Dakota Department of Health and South Dakota Game Fish and Parks recommend residents eat just one fish serving from these lakes and no other fish during the week.