Researchers at UNC-Chapel Hill are helping local fishermen identify which fish are most likely to be contaminated by chemical pollutants, and where it’s safer to eat what they catch.
The new website, Eat Fish, Choose Wisely, maps out waterways and fish species with lower levels of contamination, along with some that should be avoided entirely.
Kathleen Gray is the research translation core leader with the UNC Superfund Research Program, and the director of UNC's Environmental Resource Program.
She and others were motivated to make the guide in response to concerns that some anglers were eating fish from highly polluted water at Lake Crabtree County Park in Wake County.
In discussing the issue with local fishermen, Gray said they asked for a guide to help them assess the risks posed by different types of fish in a variety of locations.
"They really wanted a map," said Gray. "They didn't just want a map that showed where the contaminated water was, they wanted to see where nearby, ‘If I'm not going to fish and eat my catch from Lake Crabtree, where is there a nearby waterway where I can go and eat my catch'?"
Lake Crabtree is contaminated with polychlorinated biphenyls, or PCBs, a chemical linked to cancer in humans. The PCBs leaked from the former Ward Transformer manufacturing site into the soil, surface and groundwater, eventually migrating to the lake and its tributaries.
Elsewhere in the Triangle, mercury contamination from power plants and incinerators is found in lakes and streams. Mercury builds up in the human body and can harm the brain and kidneys.
Long-lived species such as carp, catfish, and large-mouth bass are more likely to accumulate unsafe levels of pollutants. Children and women of childbearing age are advised not to eat these fish, while other adults are advised to limit their consumption depending on where the fish is caught.
"We're not saying don't eat fish, we're just saying certain species may have higher levels of chemicals, and populations that are particularly vulnerable to those chemicals shouldn't eat them, or should keep track of how much they're eating," said Gray.
In addition to the maps, the guide offers advice for safe consumption of locally-caught fish. It suggests limiting portion size and only eating skinless fillets, as the chemicals can build up in the organs and fat, and remain in the fish when it’s cooked whole.