TDEC Lifts "Do Not Consume" Advisory for Silver Carp, Bighead Carp in Mississippi River in Memphis

Thursday, September 07, 2023 | 10:39am

The Tennessee Department of Environment and Conservation (TDEC) has lifted a “Do Not Consume” advisory on silver carp and bighead carp in the Mississippi River in Memphis. However, a “Do Not Consume” advisory for all other fish species in the river in Memphis remains in place.

Based on fish tissue results collected in 2022 and historical data from 2005, which document that silver carp are below Tennessee’s trigger point for all contaminants of concern, the TDEC technical staff recommended that silver carp and bighead carp be removed from the advisory.

The mercury trigger point for a precautionary advisory is 0.3 mg/kg. PCB and pesticide advisories are based on calculated risk values. Silver carp, which were also used as a surrogate for bighead carp, were below all precautionary advisory trigger points. These data establish a clear basis for removing silver carp and bighead carp from the existing “Do Not Consume” advisory regarding any fish, consistent with TDEC’s responsibilities under the Tennessee Water Quality Control Act.

“We provide these advisories so the community can make informed decisions about whether or not to consume fish where water contact hazards exist,” said TDEC Deputy Commissioner Greg Young. “Data studied from the collection in the Mississippi River have allowed TDEC to lift the previous advisory on the two species, and we are pleased to make this change. But we reiterate that the status for all other species has not changed.”

In 1982, a “Do Not Consume” advisory was issued for all fish on the Mississippi River in Shelby County due to elevated levels of Chlordane. The Tennessee Wildlife Resources Agency (TWRA) issued a commercial fishing advisory in 1985. The advisories included all fish species. The consumption advisory was expanded to include other organics including PCBs, endrin, dieldrin and dioxin in 1993. Species tested included sturgeon, buffalo common carp, catfish, carpsucker, sauger, bass and crappie. Mercury was added to the advisory in 2007.

In 2022, the TWRA, in cooperation with TDEC, collected fish for tissue analysis at two stations on the river in Shelby County. Silver carp and paddle fish were targeted. Tissue samples were analyzed for mercury, PCBs, and pesticides by the Tennessee Department of Health (TDH) through a contract with TDEC, resulting in the change of the advisory.

TDEC will update warning signs at primary public access points and will work with the TWRA to communicate this information to the public.

About Fish Consumption Advisories

The Tennessee Water Quality Control Act identifies the commissioner of the Tennessee Department of Environment and Conservation as having the authority and responsibility to issue advisories for either water contact hazards like pathogens or excessive health risks due to the accumulation of contaminants in fish or shellfish. Tennessee’s General Water Quality Criteria provide additional guidance regarding the conditions under which advisories may be warranted.

For a complete listing of Tennessee’s current fishing advisories plus additional information about the advisory issuance process, visit this link.