Signs warn fishers at Lake Crabtree...
Signs warn fishers at Lake Crabtree... Photo credit: Catherine Clabby

By Catherine Clabby

A young fisherman working a black rod on the shore of Lake Crabtree in Morrisville last week followed the rules when he hooked an 18-inch long carp.

He palmed the shiny catch briefly to get a good look. Then he twisted it loose from his hook and slipped it back into tea-colored water from where it came.

But not everyone abides by Crabtree Lake’s catch-and-release rule.

They should.

Some fish in the Wake County recreation destination are contaminated with toxic polychlorinated biphenyls (PCBs) from a nearby EPA Superfund site.

“There are signs all over, but some don’t read them. Some just ignore them,” said the young fisherman, identifying himself only as Matthew.

Management at Lake Crabtree and a local riverkeeper have seen the same. They hope a new publication and website called Eat Fish, Choose Wisely will help put fewer fishermen and their families at risk.

Ignored or unrecognized?

People eating tainted fish they catch themselves in polluted waters is a problem in many parts of he country, said Sarah Yelton, an environmental education coordinator for the UNC-Chapel Hill Institute for the Environment.

People with low incomes are more likely to eat their catch. Those very same people can be least likely to know about the origin or extent of chemical contamination — which may produce no change in odor and taste.

UNC Superfund Research Program staff decided to try to help at Lake Crabtree County Park after the manager there, Drew Cade, and Upper Neuse Riverkeeper Matthew Starr alerted them to what was happening.

A first step was surveying people who fish in the tainted waters, Yelton said.

“As we started to talk to people, it became clear that they wanted to know what was in the fish and why the lake was contaminated. And they wanted to know where else they could go fishing,” she said.

In North Carolina, most freshwater fishes are safe to eat. But risks do swim beneath the surface.

Matthew shows off his carp bait ball. Photo credit: Catherine Clabby
Matthew shows off his carp bait ball. Photo credit: Catherine Clabby

PCBs dumped at Ward Transformer, a onetime manufacturing company whose nearby property is now an EPA Superfund site, long ago invaded Crabtree Lake and nearby streams.

The now-banned chemical compounds, accumulate in concentrated amounts in the tissue of some fish, especially longer-lived predators. PCB exposure is known to harm lab animals, particularly offspring born to or nursed by animals exposed to PCBs. Among people, our knowledge is not definitive. Some studies have found lower-than-normal-weight babies born to women who consumed high amounts of PCB-contaminated fish and other chemicals. Other research has detected immune system deficiencies in babies born to and nursed by mothers exposed to PCBs.

PCBs aren’t the only danger in North Carolina’s freshwater hook-to-table food chain. Mercury has accumulated in some fish in creeks, rivers, and lakes all over North Carolina. Originating mostly from smokestack emissions at electricity generation plants and incinerators, the mercury fell directly into waterways or got washed in by rain.


Children, babies, and nursing mothers are at greatest risk of harm from eating fish contaminated by mercury, which can hurt nerve cells in the developing fetus if eaten in large enough quantities.

In addition to warning about risks from mercury-contaminated fish statewide, the Department of Health and Human Services lists more than 20 bodies of water where tainted fish may pose health risks.

No green lights

With two contaminants of concern in the Triangle, the UNC team found themselves with a less-than-simple story to tell. Choose Wisely tackles it in English and Spanish, and with lots of images.

Pictures of fish posing the greatest risk in some spots — carp, catfish, and largemouth bass — are covered in the universal “Do Not” sign, a bold red circle and angled line.

Safe serving sizes are shown with the the right amount nestled in an adult’s hand, with separate sizes endorsed for children and adults, guidance that’s a lot more direct that ounce measurements alone.

Superfund Research Program, UNC Institute for the Environment
Warnings diagram the size of a safe serving of fish. Superfund Research Program, UNC Institute for the Environment

The new guidance also includes a color-coded map of lots of sizable freshwater bodies in the Triangle. Because of the widespread mercury risks, present in waters in much of the United States, a red (don’t ever eat fish from here), yellow (just eat some fish from here), or green (eat up) color key was not feasible, Yelton said.

Instead, the color code includes a purple/red for sites where no fish should be consumed and a yellow/orange for sites where some fish can be eaten some of the time. The yellow hue circles most bodies of water on the map, including the Eno River, Falls Lake, New Hope Creek, Jordan Lake.

Children and women ages 15 to 44 should never eat wild largemouth bass caught in this state due to mercury contamination, Choose Wisely counsels. Everyone else should consume no more than one meal per week of those fish.

Southeast of I-85, wild catfish, blackfish, jack fish (chain pickerel), warmouth and yellow perch should not be eaten by women ages 15 to 44 or children. Everyone else would eat only one meal per week.

Fish warnings
Image courtesy: Superfund Research Program, UNC Institute for the Environment

That might surprise many, said Starr.

“Cat fish is big staple. It’s hard to find a fish fry in North Carolina that is not doing catfish nuggets,” he said.

Striking a balance

Starr, Crabtree Lake manager Drew Cade, and the UNC experts are not trying to scare people away from eating freshwater fish. It’s an excellent source of protein that a mother, father, or kid with limited money can bring home for little cost. All it takes is a fishing license, a rod, the right bait, and some skill.

But while making his rounds on big and small waterways, Starr sees white, black, and brown people stash suspect fish into five-gallon pails that are easy to carry home. He is not always the best person to sound an alarm.

“When I approach them and ask if they are keeping the fish they catch, they say no. Or they leave before I can ask them,” he said. “I probably look like law enforcement.”

A survey of people who fish in North Carolina published early this year in the North Carolina Medical Journal also concluded that people are ill informed about fishing risks.

Conducted in part by UNC researchers not affiliated with the Choose Wisely effort, researchers questioned 50 people who fish for food in the Haw River Basin and Jordan Lake. Eight said they ate fish high in mercury. More were unaware that state health officials warned against eating some fish here due to mercury risks. Spanish speakers were less likely to know than were English speakers.

The researchers recommended that better information be made available to all Spanish-speaking people, pregnant women, and women of childbearing age.

The UNC Superfund Program is trying to do just that, said Kathleen Gray, leader of the program’s research translation core. It will circulate its advice to churches, medical clinics, cultural festivals such as La Fiesta Del Pueblo in Raleigh, and social social service sites that grant subsistence waivers to fishermen who cannot afford licenses. It will also translate the current Choose Wisely text to language accessible to people with limited reading skills,

“We have this scientific knowledge. We know the risk,” Starr said.

“This information needs to not just stay in scientific community. This needs to get to people it is most definitely affecting.”

This story was changed to correct Kathleen Gray’s title. The story originally said she was director of the UNC Superfund Program. 

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Catherine Clabby (senior environmental reporter) is a writer and editor. A former senior editor at American Scientist magazine, Clabby won multiple awards reporting on science, medicine and higher education for the The Raleigh News & Observer. She is an alumna of the year-long Knight Science Journalism Program at MIT. Contact: catherine.clabby@gmail.com