Jefferson County Health Department officials want to remind people not to eat sunfish from the Big River because of lead contamination.
The Big River has long been under a Missouri Department of Health and Senior Services fish advisory because of that contamination, at least since 2020, but the Health Department posted a warning to social media on July 21 reminding people of the dangers of eating fish from that river.
The Big River runs through much of Jefferson County and is a tributary of the Meramec.
“No amount of lead is safe,” said Brianne Zwiener, the Jefferson County Health Department’s public information officer.
She recommends that people who fish in the Big River just catch and release them.
“It’s better to be safe than sorry,” Zwiener said.
The advisory recommends people not eat sunfish, which includes longear sunfish, green sunfish, bluegill, warmouth and rock bass, of any size.
In addition to the Big River advisory because of lead contamination, all Missouri bodies of water are under an advisory for mercury contamination for largemouth bass, smallmouth bass, spotted bass and walleye that are more than 12 inches long and for flathead catfish, channel catfish and blue catfish that are more than 30 inches long.
The DHSS recommends that people only eat bass and walleye once a month and catfish just once a week.
“Large amounts of mercury is similar to lead, so it can cause cognitive developmental delays,” Zwiener said.
The Mississippi and Missouri rivers also have an advisory for PCBs (polychlorinated biphenyls) and chlordane.
Jeff Wenzel, chief of the DHSS’ Bureau of Environmental Epidemiology, said PCBs and chlordane are dangerous chemicals that are no longer used.
“However, both chemicals do not easily break down and can remain in the environment for a long time and both have the potential to bioaccumulate in fish,” he said.
“They continue to be found in some species of fish in certain water bodies in Missouri.”
Species in the Mississippi and Missouri rivers affected by those chemicals include shovelnose sturgeon, sturgeon eggs, flathead catfish, channel catfish, blue catfish, common carp and buffalo. People are advised not to eat sturgeon and buffalo of any size, no catfish more than 17 inches long and no carp longer than 21 inches.
DHSS recommends eating sturgeon and buffalo only once a month, not eating sturgeon eggs and only eating catfish and carp once a week.
Wenzel said the first record of any fish advisory issued for the Big River is from Sept. 12, 1980, when people were discouraged from eating redhorse suckers. He said all the fish advisories are recommendations and not requirements.
Wenzel said the removal of an advisory depends on the history of the site, the level of the contamination and the level of the advisory.
“For a location like the Big River that has a known contaminant release and a do-not-consume advisory for panfish, carp and suckers, we would need to see at least three years of data showing contaminant levels below risk values,” Wenzel said.
Fish advisories are issued by DHSS after the Missouri Department of Conservation tests fish for contaminants.