The omega-3 fatty acids found in seafood are derived from phytoplankton, the small aquatic plant cells that are a source of food for many aquatic organisms. Omega-3 fatty acids are found throughout the aquatic food chain, and all fish and shellfish used for human food are sources of omega-3 fatty acids. The amount of total fat and omega-3 fatty acids found in different species of fish and shellfish can vary depending on a number of factors including the diet of each species, the season and location of the catch, the age and physiological status of the individual organism, and reproductive cycles. In most cases the amount of omega-3 fatty acids is related to the total fat content of the species. Darker fleshed fish such as herring, salmon, mackerel and bluefish generally have a higher total fat content than leaner fish species with lighter colored flesh such as cod, flounder, and pollock. Since a significant portion of this fat is omega-3 fatty acids, the darker, oily fish also tend to have the highest level of omega-3s. The following Table contains the omega-3 fatty acid content of some of the most frequently consumed fish and shellfish species in the U.S.

Health organizations suggest an EPA+DHA intake of at least 250 to 500 mg per day. The American Heart Association recommends 1000 mg of EPA+DHA per day for patients with coronary heart disease, and two meals of oily fish per week for people without heart disease. The 2010 Dietary Guidelines for Americans also advice eating a variety of seafood twice per week, 8 ounces or more, will provide the recommended 250 mg per day for optimal health.

Omega-3 Content of Frequently Consumed Seafood Products

Source: USDA National Nutrient Database for Standard Reference