The Tennessee Department of Environment and Conservation is expanding a warning to Little River anglers based on mercury pollution levels: Don’t eat the black bass.
A Monday press release warns pregnant or nursing mothers and children should avoid eating any black bass from Little River. Recreational activities in the river will not put people at risk, the release stipulated, but eating the bass will.
Trout, however, is currently not a problem. The agency said this species has “generally low levels of mercury.”
Cooperative fish sampling by TDEC and the Tennessee Wildlife Resources Agency ultimately led to the expanded advisory. Fish were collected from Townsend downstream to Maryville, and documented mercury levels were above the department’s current trigger level, the release states.
That trigger point, 0.3 mg/kg or parts per million, is recommended by both the U.S. Environmental Protection Agency and U.S. Food and Drug Administration.
Where is mercury coming from?
TDEC said atmospheric deposition is to blame, a process the EPA explains can be caused by global coal burning, though industrial processes and waste incineration also have increased mercury in some areas.
Local warnings related to fish contaminated by mercury have been issued by TDEC before. In June 2019 it announced an impacted segment of river from the national park boundary upstream of Townsend near river mile 35 to “The Sinks,” near mile 41.5.
Precautionary advisories are less severe than “do not consume” fishing advisories but still point to low contamination that could pose a risk to “sensitive populations.”
“The primary way people in the U.S. are exposed to mercury is by eating fish containing methylmercury,” TDEC explained in information accompanying releases on fish consumption warnings. Methylmercury is a toxic form of mercury that accumulates easily in organisms.
Signs to be posted
The new advisory spans all the way from the park boundary to the U.S. Highway 129 bridge near Maryville.
Additionally, though the previous warning was only for smallmouth bass, the release indicated that was because there were no black bass in that first length of river.
“We provide these advisories so people can make informed decisions about whether or not to consume fish they catch,” TDEC Deputy Commissioner Greg Young said in the release. “Precautionary fish consumption advisories are directed to sensitive populations such as children, pregnant women, nursing mothers and those who may eat fish frequently from the same body of water.”
TDEC has committed to posting warning signs at the river’s public access points and is working with Tennessee Wildlife Resource Agency to communicate these issues with the public, the release stated.