Do you know how safe your Maryland-caught seafood is to eat?

For avid fishers and local seafood enthusiasts, it’s exciting that Maryland has such a wide range of waterways to fish from, but the Maryland Department of the Environment (MDE) warns us that some of the fish may not always be safe to eat.

The MDE issues fish advisories to recommend limiting or avoiding certain species of fish that can be found in some of the state’s waters. They maintain a user-friendly interactive map that helps community members follow these guidelines. Using the map, people can easily find out how often they should be eating different fish species depending on the water body they were caught in.

The data provided by the MDE is based on contaminant levels in fish tissue, which can include mercury, PCBs (Polychlorinated Biphenyl) and PFAS (per- and polyfluoroalkyl substances). Bodies of water have different levels of contaminants, which affect the species of fish differently. Not only does the map inform users on the contaminants found in a certain fish within a certain body of water, it also breaks down the frequency and advised amount that should be eaten by women of child bearing age, children and the general population.

Specific recommendations like this are important because while fish are a good source of protein, nutrients and omega fatty acids, consuming toxins may lead to a variety of health problems. Exposure to mercury has been shown to cause impairment to speech and hearing, loss of vision and muscle weakness in adults, while the effects on infants and children can also include damage to developing brains and nervous systems. PCBs and PFAS have both been found to cause cancer, immune system, reproductive system and neurological effects, as well as causing developmental effects or delays in infants and children.

The groups most at risk are children, due to their developing bodies, and women of child bearing age because they are able to pass down toxin related health issues to fetuses in the womb or to infants while nursing. Therefore, these groups often have lower fish consumption per-month recommendations. The data from the map also includes information on which specific parts of certain species should be avoided, as some fish have body areas where contaminants tend to concentrate.

Some of the important findings to note from this data include:

• While there are many water bodies where it’s safe to eat as much blue crab as desired, other areas such as the Middle and Patapsco rivers recommend avoiding consumption entirely.

• Striped bass (also known as rockfish), the most popular sport fish in Maryland, are contaminated with PFAS in some areas in addition to PCBs. The fish have a wide range on how often they should be consumed per month depending on their location.

• Large and smallmouth bass have the most variation of recommended consumption per month.

Bay jurisdictions regularly collect data to develop fish consumption advisories for waterways. The Chesapeake Bay Program’s Toxic Contaminants Workgroup has made it a priority to synthesize this scientific information to make fish and shellfish safer for human consumption. For PCBs, the Bay Program is promoting improved practices and controls to reduce and prevent effects of toxins in fish, which in turn would reduce the concentration of contaminants in fish, making them safer to eat more regularly.

While it is not necessary to eliminate fish from your diet, following fish consumption advisories, especially if you’re catching the fish yourself, can make the difference on keeping you healthy and safe. The guidelines on recommended consumption of fish and shellfish around Maryland are regularly monitored by jurisdictions, and updated by the MDE. These FCAs help inform anglers and community members consuming fish about where, what, and how much fish is safe.