The Ohio River is a celebrated waterway, supporting a complex ecosystem and serving as an important resource for millions of people across six states. Its history as a pathway for commerce and industry has introduced environmental challenges affecting its aquatic life. For those who fish the river, the central question remains: is the catch safe to eat? The answer relies on official guidance and personal choice.
Understanding Consumption Advisories
The safety of consuming Ohio River fish is governed by formal guidelines known as fish consumption advisories, which are issued by the individual state health and environmental agencies bordering the river. These advisories do not constitute a blanket ban on eating fish; rather, they establish recommended limits on the frequency of meals. This approach allows people to continue enjoying the nutritional benefits of fish, such as lean protein and omega-3 fatty acids, while managing exposure to potential contaminants.
The guidelines often differentiate between the general population and “sensitive populations,” which include pregnant women, women who plan to become pregnant, nursing mothers, and young children. Advisories for these groups are more restrictive due to the heightened risk of developmental effects from certain toxins. These recommendations are usually expressed in terms of “meals per month” or “meals per week,” with a standard meal size defined as about one-half pound of uncooked fish for an adult.
To find the specific guidance, anglers must consult the current advisories published by the state where they are fishing. The Ohio River Valley Water Sanitation Commission (ORSANCO) plays a coordinating role, collecting fish tissue data to help the states along the river maintain consistent advice. Ultimately, the decision to eat the fish is conditional, requiring a check of the latest state recommendations based on the species and location of the catch.
Key Contaminants Driving Restrictions
The primary reason for consumption advisories stems from the presence of contaminants that bioaccumulate in fish tissue, meaning their concentration increases over the fish’s lifetime. Polychlorinated Biphenyls (PCBs) and mercury are the two main chemicals driving most restrictions across the Ohio River. PCBs are man-made industrial compounds once used in electrical equipment and hydraulic fluids. Although their production has been banned for decades, they persist in the river sediment.
PCBs are lipophilic, meaning they are attracted to and stored primarily in the fatty tissues of the fish. When fish are consumed, these compounds can enter the human body and pose a long-term health risk. Mercury, often present as methylmercury, is a heavy metal that enters the river from both atmospheric deposition and industrial discharges within the watershed. Unlike PCBs, methylmercury accumulates mainly in the muscle tissue of the fish.
Mercury is a potent neurotoxin. Sensitive populations face stricter consumption limits because exposure can impair memory, language, and cognitive function in the developing fetus or child. Emerging contaminants, such as Per- and polyfluoroalkyl substances (PFAS), are also being monitored through fish tissue sampling programs, indicating that the list of chemicals of concern is always evolving.
Variability in Risk: Location, Species, and Size
A single advisory cannot cover the entire Ohio River due to significant variability in contaminant levels driven by biological and geographical factors. The type of fish caught plays a large role in its contaminant load based on its position in the food chain, a process known as biomagnification. Predatory fish, such as Flathead Catfish, Sauger, and White Bass, tend to accumulate higher levels of contaminants because they consume many smaller fish over their lifetime.
Conversely, smaller, non-predatory species that feed lower on the food chain generally have lower concentrations of toxins. The age and size of the fish are also important determinants of risk. Larger, older fish have had more time to be exposed to and store persistent contaminants in their bodies compared to their younger, smaller counterparts. For example, advisories may specifically target Channel Catfish over a certain length because they are older and therefore more contaminated.
Geographic location along the 981-mile river also causes contamination levels to fluctuate. Areas near former or current industrial sites may have localized hotspots of pollution, leading to more restrictive consumption advice in those river pools or stretches. ORSANCO divides the river into reporting units to account for these regional differences.
Minimizing Exposure Through Preparation
For those who choose to consume fish from the Ohio River, certain preparation and cooking methods can substantially reduce the actual amount of contaminants ingested. Because chemicals like PCBs are stored in fat, the initial step is to trim away all fatty areas from the fillet before cooking. This involves removing the skin and excising the fat found along the belly flap, the lateral line, and the dorsal area of the fish.
Contaminants stored in fat can be minimized by selecting cooking methods that allow the fat to drain away from the meat. Baking, broiling, or grilling the fish on a rack are preferred methods, as the heat renders the fat, letting it drip off the fillet. Conversely, pan-frying or deep-frying are not recommended because the fat and its stored contaminants are often sealed into the fish or absorbed back into the meat.
If the fish is poached or deep-fried, the cooking oil or liquid should be discarded and not reused for other parts of the meal. It is also advised to avoid using the fish to make soups or chowders, as this cooking process retains all the fat and any contaminants that leach out. By carefully trimming and cooking the fish, consumers can reduce their exposure to fat-soluble contaminants.