Largemouth Bass caught in Sutton Lake in New Hanover County were found to have elevated levels of mercury in their tissue, according to tests conducted by state environmental officials.
The findings, verified last month, prompted the state Department of Health and Human Services to recommend that fishers at Sutton Lake adhere to the statewide mercury advisory for Largemouth Bass. That advisory recommends that women ages 15 to 44, pregnant or nursing women, and children under 15 should not eat these fish. Other people can eat up to one meal per week. A meal is 6 ounces of uncooked fish for adults, or 2 ounces of uncooked fish for children under 15, according to DHHS.
Mercury can harm brain and neurological development in fetuses and young children, which can result in cognitive disabilities later in life. Adults with mercury poisoning can experience tingling or numbness of lips, tongue, fingers or toes, fatigue, and blurred vision.
In March DEQ sampled 11 largemouth bass, three bluegill sunfish and eight redear sunfish. All of the Largemouth Bass samples contained some amount of mercury. The average concentration was 0.13 ppm, more than two and a half times the state’s health screening level of 0.047 ppm. Detections in the bass ranged from 0.07 to o.23 ppm.
One of three bluegill tested and five of eight redear sunfish also had mercury, but at amounts below the screening level. In a letter to New Hanover County Public Health Department Director Phillip Tart, state health officials noted that because of an insufficient number of bluegill samples, they could not issue an advisory for that species at Sutton.
DHHS cautioned that concentrations could increase or decrease over time, and recommended that DEQ continue to sample the fish not only for mercury, but other contaminants, “to accurately assess the status of fish” in the lake.
The industrial sources of mercury include coal-fired power plants and incinerators. Duke Energy operated the Sutton coal-fired plant adjacent to the lake from 1954 to 2013.
There has been a statewide fish consumption advisory in effect for mercury since 2008. According to state documents, most of the elevated mercury concentrations in Largemouth Bass occur in the eastern and southeastern part of the state, within the Coastal Plain.