DNREC monitors the presence of chemical contaminants in the edible flesh of finfish and shellfish in Delaware waters. In coordination with the Department of Health and Social Services (DHSS), they issue periodic fish consumption advisories to guide anglers on the amount of fish they can safely consume from specific water bodies to increase risk awareness.

This page contains information on how legacy pollutants impact the safety of finfish and shellfish, the general statewide fish consumption advisory, current advisories for specific water bodies and fish species, and ways you can reduce your risk.

Legacy Pollutants

Many of the contaminants that prompt fish advisories in Delaware are considered “legacy pollutants.” These are chemicals such as polychlorinated biphenyls (PCBs), the banned insecticide DDT and dioxins and furans that were released into waterways in significant quantities in the past. These legacy pollutants are slow to break down in the environment and remain in streams and estuaries, where they represent continuous sources of exposure to aquatic life.

Even when present in the water or sediment in extremely small amounts, some chemicals tend to accumulate in fish tissue because fish absorb contaminants from the water and sediment, and from the food they eat.

The amount of contaminants fish accumulate depends on the species, size, age, sex, and the feeding area of the fish.

In general, older, larger individual fish will have accumulated the most contaminants. Since fish accumulate many contaminants in their fatty tissues, species with higher fat/oil content can pose more risk than others.

In recent years, DNREC’s data has indicated improvements in concentrations of most contaminants in fish tissue across the state. This reduction is attributed to regional and local efforts, including state-of-the-science testing to identify, prioritize and control remaining sources of contaminants, and innovative clean-up strategies that are effectively reducing the transport of chemicals and their subsequent availability to accumulate in fish and other aquatic organisms.

For PCBs, the primary chemical driving fish consumption advisories, DNREC and its partners, including the Delaware River Basin Commission, New Castle County Special Services, the City of Wilmington, state environmental agencies in Pennsylvania and New Jersey, and industrial facilities, have been working cooperatively on strategies and projects that implement the Delaware Estuary total maximum daily load (TMDL)

General Statewide Fish Consumption Advisory

Fish consumption advisories are recommendations by DNREC and DHSS to limit or avoid eating certain species of fish caught in local waters due to potential health risks from contaminants.

DNREC and DHSS remind the public of the general statewide fish consumption advisory to eat no more than one 8-oz. meal per week of any fish species caught in Delaware’s fresh, estuarine and marine waters. This advisory applies to all waters and fish species not otherwise explicitly covered by a specific advisory.

The statewide advisory is issued in an abundance of caution to protect against eating large amounts of fish or fish that have not been tested, or that may contain unidentified chemical contaminants.

Delaware issues more stringent advice for specific waters when justified by the data collected. One meal is defined as an eight ounce serving for adults and three ounce serving for children.

A description of the procedures used by DNREC and DHSS to calculate recommended fish consumption limits can be found in the document: Technical Procedures for Evaluating Human Health Risks Associated with the Consumption of Chemically Contaminated Fish and Shellfish.

Current Fish Consumption Advisories

The most recent Delaware Fish Consumption Advisories are shown in the chart below or can and are available for download. Contaminants of concern that are responsible for the advisories are listed along with the maximum number of meals per year that are recommended to minimize potential health impacts from consuming the fish. 

Fish consumption advisories for individual water bodies are updated as new data is collected and assessed, usually every five to seven years, depending upon available funding for sample collection and analysis.

Delaware Fish Consumption Advisories

For more information, contact DNREC at 302-739-9939 or the DHSS Division of Public Health at 302-744-4546.

Reducing Your Risk

Most contaminants tend to concentrate in a fish’s fatty tissue, so deliberate cleaning and cooking techniques can significantly reduce levels of PCBs, dioxins, chlorinated pesticides and other organic chemicals in the portion that is eaten. Larger fish tend to have higher concentrations.

Proper cleaning and preparation of fish can reduce the chance of consuming chemical contaminants:

• Remove all skin from the fish. 
• Cut away any fat above the fish’s backbone. 
• Cut away the V-shaped wedge of fat along the lateral line on each side of the fish.
• Remove fat belly meat along the bottom of the fish.

Bake or broil trimmed fish on a rack or grill so some of the remaining fat can drip away. Discard any drippings; do not eat drippings or use them for cooking other foods.

Note: These techniques will not reduce or remove unsafe levels of mercury or PFAS from fish, as they tend to accumulate in muscle tissue (meat) as opposed to fat.

People who are or may become pregnant, people who are breastfeeding or plan to breastfeed, and children under the age of 15 may want to avoid eating any species of fish suspected to impacted by contaminants.

For more information about fish and shellfish consumption advisories around the United States, visit the EPA Fish Consumption Advisories page.

Related Topics:  advisories, assessment, fish and wildlife, fish consumption, fishing, Health and Safety, outdoors and recreation, watershed stewardship