A mercury advisory was issued by the state Department of Environment and Conservation for consumption of fish taken from state lakes and rivers.
Local waters under the advisory include the Watauga Reservoir, Upper Holston Lake in Tennessee and the Holston River from the confluence of North and South Fork near Kingsport to the mouth of Poor Valley Creek.
All fish species in the Holston are affected, largemouth bass and channel catfish in the Watauga and largemouth bass in South Holston.
The North Fork of the Holston above the confluence is already under a “do not consume” advisory due to mercury contamination.
These additions to Tennessee’s list of precautionary fish consumption advisories is the result of the trigger point for a mercury advisory being lowered to 0.3 parts per million.
“Recent studies indicate that mercury has potential neurological effects on children at lower levels than previously thought,” said Paul Davis, director of the Division of Water Pollution Control. “Because of this new research and based on EPA’s new water quality criterion, the mercury advisory trigger point is being lowered to a more conservative level.”
The precautionary fish advisory is aimed at sensitive populations such as children, pregnant women, nursing mothers and those who eat fish frequently from the listed bodies of water.
The advisories are a step below the “do not consume” advisories that warn everyone not to eat fish from a particular body of water altogether.
State law requires the department to inform the public and post warnings where contaminants in fish pose a possible threat to people who might catch and eat them.
“Eating fish with elevated levels of mercury is a risk Tennesseans can avoid,” said Paul Sloan, deputy commissioner for environment. “Fishing advisories give fishermen and their families the information they need to make informed decisions about limiting their intake or avoiding fish from specific stream segments or bodies of water.”
Three existing advisories in West Tennessee were modified to include mercury and seven new precautionary advisories for mercury were issued Thursday.
“It is important to understand that the risk associated with these advisories pertains specifically to the consumption of fish,” Davis said. “Swimming and wading in these waters or catching and releasing fish are activities that do not expose the public to an increased risk from mercury.”
According to the EPA, mercury amounts in the environment have increased due to forest fires and human activities such as burning coal, some industrial processes and waste incineration. The primary way people are exposed to mercury is by eating fish containing Methylmercury, a toxic form of mercury that accumulates easily in organisms.
Signs are expected to be put up at primary access points, and additional fish samples will be taken this summer by the DEC and Tennessee Wildlife Resources Agency.