Joshua Haiar, South Dakota Searchlight
State officials have added two more South Dakota lakes to the fish consumption advisory list after testing found elevated mercury levels in large walleye.
The state announced Monday that Dry Lake #1 in Clark County and Lake Henry in Kingsbury County have been added to the list.
For Dry Lake #1, health officials recommend limiting consumption of walleye over 21 inches in length. At Lake Henry, the advisory applies to walleye over 24 inches. Walleye in South Dakota can grow to more than 30 inches.
The guidance is based on mercury concentrations detected in fish tissue samples collected through the state’s annual monitoring program.
“Our commitment to public health and safety drives the annual fish sampling program,” said Department of Health Secretary Melissa Magstadt in a news release.
Mercury, a toxic heavy metal, ends up in fish across the United States largely due to atmospheric deposition. Coal-fired power plants release mercury into the air before it settles into lakes and rivers. Bacteria convert it into methylmercury and fish absorb it.
Fish consumption advisories are not enforceable bans but are issued to help people make informed choices to reduce health risks.
“We encourage everyone to check the DOH website for the latest advisories and take necessary precautions when enjoying locally caught fish,” Magstadt said.
Fish consumption advisories
In addition to Dry Lake #1 and Lake Henry, these lakes are on the state’s fish consumption advisory list:
- Bitter Lake: Limit consumption of northern pike (over 30″) and any size walleye, particularly for children under age 7 and women who are pregnant, might become pregnant, or are breastfeeding.
- Coal Springs Reservoir: Limit consumption of northern pike (over 25″). These tested above recommended limits for mercury.
- Cottonwood Lake: Limit consumption of walleye (over 21″). These tested above recommended limits for mercury.
- Dry Lake Number 2: Limit consumption of walleye (over 22″). These tested above recommended limits for mercury.
- Elm Lake: Limit consumption of walleye (over 25″). These tested above recommended limits for mercury.
- Hazeldon Lake: Limit consumption of walleye (over 21″). These tested above recommended limits for mercury.
- Horseshoe Lake: Limit consumption of walleye (over 18″). These tested above recommended limits for mercury.
- Kiesz Lake: Limit consumption of walleye (over 16″). These tested above recommended limits for mercury.
- Lake Hurley: Limit consumption of Largemouth Bass (over 18″). These tested above recommended limits for mercury.
- Lake Isabel: Limit consumption of northern pike (over 25″) and Largemouth Bass (over 17″). These tested above recommended limits for mercury.
- Lake Minnewasta: Limit consumption of walleye (over 18″). These tested above recommended limits for mercury.
- Lardy Lake: Limit consumption of walleye (over 18″). These tested above recommended limits for mercury.
- Little Moreau Lake: Limit consumption of northern pike (over 26″). These tested above recommended limits for mercury.
- Long Lake: Limit consumption of walleye (over 17″). These tested above recommended limits for mercury.
- Lynn Lake: Limit consumption of walleye (over 25″). These tested above recommended limits for mercury.
- Middle Lynn Lake: Limit consumption of walleye (over 18″). These tested above recommended limits for mercury.
- New Wall Lake: Limit consumption of black and white crappie (over 13″) and Largemouth Bass (over 16″). These tested above recommended limits for mercury.
- Newell Lake: Limit consumption of walleye (over 18″) and northern pike (over 18″). These tested above recommended limits for mercury.
- North Buffalo Lake: Limit consumption of walleye (over 21″). These tested above recommended limits for mercury.
- North Island Lake: Limit consumption of walleye (over 18″) and Smallmouth Bass (over 19″). These tested above recommended limits for mercury.
- Opitz Lake: Limit consumption of northern pike (over 26″). These tested above recommended limits for mercury.
- Pickerel Lake: Limit consumption of white bass (over 16”), particularly for children under age 7 and women who are pregnant, might become pregnant, or are breastfeeding.
- Pudwell Dam: Limit consumption of walleye (over 18″) and Black Crappie (over 12″). These tested above recommended limits for mercury.
- Reid Lake: Limit consumption of walleye (over 23″) and northern pike (over 32″). These tested above recommended limits for mercury.
- Roosevelt Lake: Limit consumption of largemouth bass (over 18″) and northern pike (over 24″). These tested above recommended limits for mercury.
- Scott Lake: Limit consumption of walleye (over 25″). These tested above recommended limits for mercury.
- South Buffalo Lake: Limit consumption of walleye (over 21″). These tested above recommended limits for mercury.
- Swan Lake: Limit consumption of walleye (over 21″). These tested above recommended limits for mercury.
- Twin Lakes (Minnehaha County): Limit consumption of any size walleye, particularly for children under age 7 and women who are pregnant, might become pregnant, or are breastfeeding. Walleye tested above recommended limits for mercury.
- Twin Lakes (Brookings/Kingsbury counties): Limit consumption of walleye (over 18″) and northern pike (over 19″). These tested above recommended limits for mercury.