sealPurdue News

August 2000

Go fishing for fun, but eat more from the store

WEST LAFAYETTE, Ind. – If you're trying to add more fish to your diet, grab most of it from the grocery store shelves, says Charlie Santerre, a Purdue University professor of foods and nutrition. According to his research, you're less likely to find contaminants in store-bought fillets than in fish pulled from local streams and rivers.

"After reading stories about contaminants in catfish, we decided to start collecting data on farm-raised fish," says Santerre, who was part of a team of researchers working with the U.S. Department of Agriculture's Southern Regional Aquaculture Center. "We tested catfish, red swamp crayfish and rainbow trout that were headed for the grocery store, and we found that they're safe."

In the most comprehensive study of its kind, published in the March issue of the Journal of Food Science, Santerre and researchers from seven other states tested farm-raised fish and crayfish for more than three dozen pesticides. In almost every case, contaminant levels in pond-raised fish were lower than levels of those same pesticides and polychlorinated biphenyls in wild-caught fish from similar studies, Santerre says.

During the two-year study, Santerre tested 257 pond-raised catfish, 33 pond-raised trout and 38 pond-raised crayfish and found that they met FDA standards for PCBs, DDT, chlordane, dieldrin, hexachlorobenzene, heptachlor epoxide and several other pesticides. The first year, 10.5 percent of the catfish contained more chlorpyrifos than allowed by the FDA. By the end of that year, producers quit using the pesticide near ponds, and all catfish fillets were free of chlorpyrifos after that. No trout or crayfish had chlorpyrifos residues.

Because many of the catfish and trout fillets that end up on ice in the grocery store come from farm ponds, Santerre says, you can feel safe when you pick them up at the store.

And you should be eating fish, he says. They are a good source of protein and are full of omega-3 fatty acids. Health researchers have linked omega-3s to improved bone growth and decreased risk of coronary heart disease and some cancers.

If you fish for your own supper, however, you'd better beware, Santerre says.

"If you're going to catch fish out of rivers and streams," he says, "check the state fishing advisory to see if you should eat it, or how often you should eat it. Many waterways in many states are contaminated. In some streams and lakes along the Great Lakes, for example, PCB levels may be 10 times higher than the FDA action limit. In other waters, residues may be very low, so the bottom line is that anglers should check with state agencies before consuming wild-caught fish."

Fishermen in every state need to know which waterways are contaminated, Santerre says. They can start by checking out the Environmental Protection Agency's online database, Listing of Fish and Wildlife Advisories, or the EPA Consumption Advisory Web site, which has links to downloadable consumption advisories.

Working with the Indiana Departments of Environmental Management, Health and Natural Resources, Santerre put together a Web site that gives the Indiana Fish Consumption Advisory and pinpoints contaminated waterways in the state. Fishermen who consult the Angling Indiana site will find where in the state it's safe to eat the fish they catch.

"We recommend that if you fish areas with high levels of contamination, you 'catch and release' and buy fish to eat from a grocery store," Santerre says. "We still encourage that you enjoy fishing Indiana waters."

Source: Charlie Santerre, (765) 496-3443,

Writer: Rebecca Goetz, (765) 494-0461,

Purdue News Service: (765) 494-2096;


Organochlorines, Organophosphates and Pyrethroids
in Channel Catfish, Rainbow Trout and Red Swamp Crayfish
from Aquaculture Facilities

Santerre, C.R., R. Ingram, G.W. Lewis, J.T. Davis, L.G. Lane, R.M. Grodner, C.I. Wei, P.B. Bush, D.H. Xu, J. Shelton, E.G. Alley and J.M Hinshaw

Channel catfish (Ictalurus punctatus), rainbow trout (Oncorhynchus mykiss) and red swamp crayfish (Procambarus clarkii) were collected from eight Southern states in the U.S. and analyzed for 34 organochlorine, organophosphate and pyrethroid compounds. Approximately 45% of catfish, 72% of trout and 92% of crayfish contained no detectable residues. Most residues detected were well below action limits for fish. Chlorpyrifos, for which there is no established tolerance, was detected in catfish; however, residues of this pesticide were not detected in samples collected after the first year of the study. The data collected during this study further support the safety of aquaculture products.

* To the Purdue News and Photos Page