Making the best seafood choices for you and your family can be daunting. Compiled here is all the information you need to make healthy and environmentally friendly choices. Find out where your favorite seafood ranks in sustainability, mercury level, and omega-3 content, as well as its place in the food chain—and why it matters.
Sustainability – assessed by Monterey Bay Aquarium’s Seafood Watch.
Best – It is abundant, well managed, and caught or farmed in ocean-friendly ways.
Good – It is an option, but there are concerns with how it’s caught or farmed, or with the health of its habitat due to other human impacts.
Avoid – It is caught or farmed in ways that harm other marine life or the environment.
Omega-3 Content (mg per 6-oz serving) – the minimum recommended by nutrition experts is 250 mg/day. Levels are considered
High – One serving per week exceeds the minimum.
Adequate – Two servings per week meets or exceeds the minimum.
Low – You need to eat more than two servings per week to meet the minimum. N/A – The USDA does not currently provide information on the omega-3 content for this seafood.
Mercury Level – The reference is the EPA’s reference dose for mercury. It should be low if are pregnant, nursing, or feeding a young child. Additional information is available from Stony Brook University’s Gelfond Fund for Mercury Research & Outreach.
Low – You can consume a 6-oz. portion two or three times a week.
Moderate – You can consume one 6-oz. portion a week.
High – Consumption should be limited in individuals who eat seafood more than 2-3 times per week.
N/A – There is currently no mercury data available for this seafood item.
Refer to the note at the end about mercury if interested.
SEAFOOD A-Z
Anchovy, European
Sustainability Ranking: GOOD
Omega-3 Content: HIGH (2,464 MG)
Mercury Level: LOW (0.1 MG)
Arctic Char (Farmed)
Sustainability Ranking: BEST
Omega-3 Content: ADEQUATE (1,531 MG)
Mercury Level: N/A
Barramundi (U.S.)
Sustainability Ranking: BEST
Omega-3 Content: LOW (750 MG)
Mercury Level: N/A
Bass, Striped
This refers to hybrid striped bass that is farmed.
Sustainability Ranking: BEST
Omega-3 Content: ADEQUATE (1,281 MG)
Mercury Level: LOW (0.028 MG)
Bass, Striped/Rockfish (U.S. Hook and Line)
This refers to wild striped bass.
Sustainability Ranking: BEST
Omega-3 Content: ADEQUATE (1,281 MG)
Mercury Level: LOW (0.295 MG)
Cod, Atlantic (Imported)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (313 MG)
Mercury Level: LOW (0.07 MG)
Crab, King (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (703 MG)
Mercury Level: LOW (0.027 MG)
Crab, Red King (Russia)
Sustainability Ranking: AVOID
Omega-3 Content: LOW (703 MG)
Mercury Level: LOW (0.027 MG)
Crab, Stone
Sustainability Ranking: BEST
Omega-3 Content: N/A
Mercury Level: LOW (0.095 MG)
Crayfish/Crawfish (Farmed in China)
Sustainability Ranking: AVOID.
Omega-3 Content: LOW (29 MG)
Mercury Level: LOW (0.034 MG)
Crayfish/Crawfish (Farmed in U.S.)
Sustainability Ranking: BEST
Omega-3 Content: LOW (29 MG)
Mercury Level: LOW (0.034 MG)
Eel, Freshwater (Farmed)
Sustainability Ranking: AVOID
Omega-3 Content: LOW (250 MG)
Mercury Level: LOW (0.066 MG)
Flounder (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (417 MG)
Mercury Level: MODERATE (0.119 MG)
Grouper (U.S. Atlantic)
Sustainability Ranking: AVOID
Omega-3 Content: LOW (420 MG)
Mercury Level: HIGH (0.417 MG)
Grouper, Red (U.S. Gulf of Mexico)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (420 MG)
Mercury Level: HIGH (0.417 MG)
Haddock (Georges Bank)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (222 MG)
Mercury Level: MODERATE (0.164 MG)
Haddock (Gulf of Maine)
Sustainability Ranking: AVOID
Omega-3 Content: LOW (222 MG)
Mercury Level: MODERATE (0.164 MG)
Halibut, Atlantic
Sustainability Ranking: AVOID
Omega-3 Content: LOW (330 MG)
Mercury Level: LOW (0.043 MG)
Halibut, Pacific (U.S.)
Sustainability Ranking: BEST
Omega-3 Content: LOW (330 MG)
Mercury Level: MODERATE (0.261 MG)
Herring, Atlantic (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: HIGH (2,670 MG)
Mercury Level: LOW (0.037 MG)
Lobster (Bahamas and U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (289 MG)
Mercury Level: MODERATE (0.2 MG)
Lobster, Spiny (Belize, Brazil, Honduras, Nicaragua)
Sustainability Ranking: AVOID
Omega-3 Content: LOW (635 MG)
Mercury Level: LOW (0.1 MG)
Lobster, Spiny (Mexico)
Sustainability Ranking: BEST
Omega-3 Content: LOW (636 MG)
Mercury Level: LOW (0.1 MG)
Mackerel, King (U.S.)
Sustainability Ranking: BEST
Omega-3 Content: LOW (532 MG)
Mercury Level: HIGH (1.101 MG)
Mackerel, Spanish (U.S.)
Sustainability Ranking: BEST
Omega-3 Content: HIGH (2,279 MG)
Mercury Level: HIGH (0.44 MG)
Mahi Mahi (Imported)
Sustainability Ranking: AVOID
Omega-3 Content: LOW (184 MG)
Mercury Level: N/A
Mahi Mahi (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (184 MG)
Mercury Level: N/A
Monkfish (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: N/A
Mercury Level: MODERATE (0.174 MG)
Mussel
Sustainability Ranking: BEST
Omega-3 Content: LOW (750 MG)
Mercury Level: LOW (0.028 MG)
Octopus (Spain and U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (267 MG)
Mercury Level: N/A
Orange Roughy
Sustainability Ranking: AVOID
Omega-3 Content: LOW (33 MG)
Mercury Level: HIGH (0.513 MG)
Oyster
Sustainability Ranking: BEST
Omega-3 Content: LOW (757 MG). Omega-3 content varies by species; this listing is for the Eastern oyster.
Mercury Level: LOW (0.02 MG)
Pangasius/Basa/Swai
Sustainability Ranking: GOOD
Omega-3 Content: LOW (151 MG). Based on USDA data for catfish (NOAA).
Mercury Level: N/A
Pollock (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (280 MG)
Mercury Level: LOW (0.05 MG)
Sablefish/Black Cod (Alaska, Canada)
Sustainability Ranking: BEST
Omega-3 Content: HIGH (2,372 MG)
Mercury Level: MODERATE (0.243 MG)
Sablefish/Black Cod (California, Oregon, Washington Wild Caught)
Sustainability Ranking: GOOD
Omega-3 Content: HIGH (2,372 MG)
Mercury Level: MODERATE (0.243 MG)
Salmon (Alaska)
Sustainability Ranking: BEST
Omega-3 Content: HIGH (3,319 MG). Omega-3 content varies by species; chinook have the highest content (3319 mg) and pink the lowest (875 mg).
Mercury Level: LOW (0.048 MG)
Salmon (California, Oregon, Washington Wild Caught)
Sustainability Ranking: GOOD
Omega-3 Content: HIGH (3,319 MG). Omega-3 content varies by species; chinook have the highest content (3319 mg) and pink the lowest (875 mg).
Mercury Level: LOW (0.048 MG)
Salmon, Atlantic (Farmed)
Sustainability Ranking: AVOID
Omega-3 Content: HIGH (3,342 MG)
Mercury Level: LOW (0.026 MG)
Sardine, Pacific (Canada and U.S.)
Sustainability Ranking: BEST
Omega-3 Content: HIGH (2,372 MG)
Mercury Level: LOW (0.078 MG)
Scallop (Farmed)
Sustainability Ranking: BEST
Omega-3 Content: LOW (299 MG)
Mercury Level: LOW (0.04 MG)
Scallop (Wild)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (299 MG)
Mercury Level: LOW (0.04 MG)
Shark
Sustainability Ranking: AVOID
Omega-3 Content: ADEQUATE (1,433 MG)
Mercury Level: HIGH (0.882 MG)
Shrimp (Canada, U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (104 MG)
Mercury Level: LOW (0.053 MG)
Shrimp (Imported Farmed)
Sustainability Ranking: AVOID
Omega-3 Content: LOW (104 MG)
Mercury Level: LOW (0.053 MG)
Shrimp, Pink (Oregon)
Sustainability Ranking: BEST
Omega-3 Content: LOW (104 MG)
Mercury Level: LOW (0.083 MG)
Skate (U.S. Atlantic)
Sustainability Ranking: AVOID
Omega-3 Content: LOW (104 MG)
Mercury Level: MODERATE (0.138 MG)
Snapper, Red (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (529 MG)
Mercury Level: MODERATE (0.243 MG)
Sole (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (417 MG)
Mercury Level: LOW (0.086 MG)
Squid (Imported)
Sustainability Ranking: AVOID
Omega-3 Content: LOW (829 MG)
Mercury Level: LOW (0.044 MG)
Squid (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (829 MG)
Mercury Level: LOW (0.044 MG)
Swordfish (Imported)
Sustainability Ranking: AVOID
Omega-3 Content: ADEQUATE (1,282 MG)
Mercury Level: HIGH (0.893 MG)
Swordfish (U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: ADEQUATE (1,282 MG)
Mercury Level: HIGH (0.893 MG)
Tilapia (Ecuador and U.S.)
Sustainability Ranking: GOOD
Omega-3 Content: LOW (156 MG)
Mercury Level: LOW (0.019 MG)
Tilapia (Ecuador and U.S. Farmed)
Sustainability Ranking: BEST
Omega-3 Content: LOW (156 MG)
Mercury Level: LOW (0.019 MG)
Trout, Rainbow (U.S. Farmed)
Sustainability Ranking: BEST
Omega-3 Content: ADEQUATE (1,246 MG)
Mercury Level: LOW (0.029 MG)
Tuna, Albacore/White Canned (Canada & U.S. Troll, Pole)
Sustainability Ranking: BEST. When possible, look for troll- or pole-caught albacore. In particular, U.S. and Canadian North Pacific are the best choices. Longline-caught albacore should be avoided, except longline-caught from Hawaii, where strict bycatch regulations and healthy populations are a good alternative.
Omega-3 Content: ADEQUATE (1,465 MG)
Mercury Level: HIGH (0.328 MG)
Tuna, Skipjack/Light Canned (FAD-free; Troll, Pole)
Sustainability Ranking: BEST
Skipjack tuna caught with troll or pole gear receive a “Best Choice” recommendation because there is little or no bycatch associated with this collection method. US longline is a good alternative. Imported Longline and Purse Seine should be avoided.
Omega-3 Content: LOW (459 MG)
Mercury Level: MODERATE (0.131 MG)
Tuna, Albacore, Bigeye, Bluefin
These three species of tuna have the same sustainability ranking and are in the same categories for mercury and omega.
Sustainability Ranking: AVOID
Omega-3 Content: ADEQUATE (1,729 MG)
Tuna, Yellowfin (U.S. Troll, Pole)
Sustainability Ranking: BEST
Yellowfin caught via U.S. troll or pole is considered a best choice. Imported troll, pole; U.S. longline is considered a good alternative. Avoid purse seine and longline caught yellowfin that is not from the U.S. or Hawaii.
Omega-3 Content: LOW (170 MG)
Mercury Level: MODERATE (0.565 MG)
Yellowtail (Australia and Japan Farmed)
Sustainability Ranking: AVOID
Omega-3 Content: N/A
Mercury Level: N/A
Yellowtail (California)
Sustainability Ranking: GOOD
Omega-3 Content: N/A
Mercury Level: N/A
MERCURY – Everything you want to know
How People are Exposed to Mercury.
Mercury exists in various forms, and people are exposed to each in different ways. The most common way people in the U.S. are exposed to mercury is by eating fish containing methylmercury. Other exposures may result from using or breaking products containing mercury.
If you are concerned for your health or your family’s as a result of exposure to mercury, get in touch with your health care provider. They will be able to tell you if mercury exposure is a problem for you and what to do about it.
Exposure to Methylmercury. Although most people have mercury levels in their bodies below the level associated with possible health effects, almost all people in the world have at least trace amounts of methylmercury in their bodies, reflecting its pervasive presence in the environment. Nearly all methylmercury exposures in the U.S. occur through eating fish and shellfish that contain higher levels of methylmercury.
Some communities eat significantly more quantities of fish than the general population, and thus may be exposed to much greater mercury contamination than the general population.
In addition, in past outbreaks of methylmercury poisoning, mothers with no symptoms of nervous system damage gave birth to infants with severe disabilities; as a result, it became clear that the nervous system of a developing fetus may be more vulnerable to methylmercury exposures than the adult nervous system. Mothers who are exposed to methylmercury and breast-feed may also expose their infant children through their milk.
How Mercury Enters the Environment
Mercury is emitted to the air by human activities, such as manufacturing or burning coal for fuel, and from natural sources, such as volcanoes.
Typically, mercury is released into the atmosphere in one of three forms:
• elemental mercury: can travel a range of distances, may remain in the atmosphere up to one year and may travel globally before undergoing transformation
• particle-bound mercury: can fall out of the air over a range of distances
• oxidized mercury (sometimes called ionic or reactive gaseous mercury (RGM)): found predominantly in water-soluble forms, which may be deposited at a range of distances from sources depending on a variety of factors including topographic and meteorologic conditions downwind of a source.
What happens to mercury after it is emitted depends on several factors:
• the form of mercury emitted,
• the location of the emission source,
• how high above the landscape the mercury is released (for example, the height of a power-plant stack),
• the surrounding terrain, and
• the weather.
Depending on these factors, atmospheric mercury can be transported over a range of distances before it is deposited, potentially resulting in deposition on local, regional, continental and/or global scales. Mercury that remains in the air for prolonged periods of time and travels across continents is said to be in the “global cycle.”
Mercury Emissions Around the Globe
Recent emissions estimates of annual global mercury emissions from all sources, natural and anthropogenic (human-generated), which are highly uncertain, are about 5,000-8,000 metric tons per year.
U.S. anthropogenic mercury emissions are estimated to account for roughly three percent of the total global emissions, and the U.S. power sector is estimated to account for about one percent the total global emissions. EPA has estimated that about one-third of U.S. emissions are deposited within the contiguous U.S. and the remainder enters the global cycle.
Current estimates are that less than half of all mercury deposition within the U.S. comes from U.S. sources, although deposition varies by geographic location. For example, compared to the country as a whole, U.S. sources represent a greater fraction of the total deposition in parts of the Northeast because of the direction of the prevailing winds.
Moving Up the Food Chain
When mercury falls in rain or snow, it may flow into bodies of water like lakes and streams. When it falls out of the air as dry deposition, it may eventually be washed into those bodies by rain. Bacteria in soils and sediments convert mercury to methylmercury. In this form, it is taken up by tiny aquatic plants and animals. Fish that eat these organisms build up methylmercury in their bodies. As ever-bigger fish eat smaller ones, the methylmercury is concentrated further up the food chain. This process is called “bioaccumulation”.
Methylmercury concentrations in fish depend on many factors, including mercury, the concentration in water, water pH and temperature, the amount of dissolved solids and organic matter in the water, and what organisms live in the water. Methylmercury concentrations in fish may also be affected by the presence of sulfur and other chemicals in the water. Because of these variables, and because food webs are very complex, bioaccumulation is hard to predict and can vary from one water body to another.
However, in a given water body, the highest concentrations of methylmercury are generally found in large fish that eat other fish. The concentrations of methylmercury in large fish can be over a million-fold larger than in the surrounding water..
What EPA and Other Federal Agencies are Doing to Help Reduce Exposures to Methylmercury
Reference Dose (RfD):
Formal Definition
An estimate (with uncertainty spanning perhaps an order of magnitude) of a daily oral exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime. It can be derived from a NOAEL, LOAEL, or benchmark dose, with uncertainty factors generally applied to reflect limitations of the data used. Generally used in EPA’s noncancer health assessments.
No-Observed-Adverse-Effect Level (NOAEL): The highest exposure level at which there are no biologically significant increases in the frequency or severity of adverse effect between the exposed population and its appropriate control; some effects may be produced at this level, but they are not considered adverse or precursors of adverse effects.
Lowest-Observed-Adverse- Effect Level (LOAEL): The lowest exposure level at which there are biologically significant increases in frequency or severity of adverse effects between the exposed population and its appropriate control group
Understanding What Levels of Mercury Exposure Might Affect Human Health
In 1997, EPA published the Mercury Study Report to Congress to fulfill requirements of the Clean Air Act Amendments of 1990. The report is an eight-volume assessment of the magnitude of U.S. mercury emissions by source; the health and environmental impacts of those emissions; and the availability and cost of control technologies.
EPA has also calculated a reference dose (RfD) level for methylmercury. An RfD is EPA’s estimate of the maximum acceptable daily exposure to humans that is not likely to cause harmful effects during a lifetime (see a more detailed definition in the box at right). EPA’s RfD for methylmercury, last revised in 2001, is currently 0.1 micrograms per kilogram of body weight per day.
Measuring and Monitoring the Number of People at Risk from Methylmercury Exposure
Human biological monitoring by the Centers for Disease Control and Prevention shows that most people have blood mercury levels below the level associated with possible health effects
As described in EPA’s 2013 (1.5 MB, 81 pp.), blood mercury analyses in 16-to-49-year-old women showed that approximately 2.3% of women had blood mercury concentrations greater than 5.8 micrograms per liter (which is a blood mercury level equivalent to the current RfD). This percentage represents an estimated 1.4 million women of reproductive age who have blood mercury concentrations that may increase the risk of learning disabilities in their unborn children. Based on this prevalence and the number of U.S. births each year. It is estimated that more than 75,000 newborns each year may have increased risk of learning disabilities associated with in-utero exposure to methylmercury.
Providing Consumers with Advice to Reduce Exposures
Exposures to Elemental Mercury
When elemental mercury is spilled or a device containing mercury breaks, the exposed elemental mercury can evaporate and become an invisible, odorless toxic vapor. This is especially true in warm or poorly-ventilated rooms or spaces. Sources of potential exposure to elemental mercury are described below.
• Household and commercial consumer products: Metallic mercury is often found in school laboratories as well as in thermometers, barometers, switches, thermostats, and electrical switches.
• Fever thermometers: It is not uncommon for children to break fever thermometers in their mouths. Mercury that is swallowed in such cases poses low risk comparison to the risk of breathing mercury vapor.
• Novelty jewelry: Some necklaces imported from Mexico contain a glass pendant that contains mercury. The mercury-containing pendants can come in various shapes such as hearts, bottles, balls, saber teeth, and chili peppers. If broken, they release metallic mercury to the environment.
• Dental amalgam: Mercury is used in dentistry in dental amalgam. Dental amalgam is a direct filling material used in restoring teeth. It is made up of approximately 40-50% mercury, 25% silver and 25-35% a mixture of copper, zinc and tin. Amalgam use is declining because the incidence of dental decay is decreasing and because improved substitute materials are now available for certain applications.
• Gold Mining: Elemental mercury is sometimes used in artisanal and small-scale gold mining. Mercury is mixed with gold-containing materials, forming a mercury-gold amalgam which is then heated, vaporizing the mercury and leaving the gold. This process is very dangerous and can lead to significant mercury exposure. Miners working tailings in areas where mercury was previously used can also be inadvertently exposed to the residual mercury in these deposits
What EPA and Other Federal Agencies are Doing to Help Reduce Exposures to Elemental Mercury
Developing Technologies to Prevent Mercury Emissions into the Air
To reduce airborne mercury emissions from small-scale gold buying and refining facilities located in over 55 countries around the world, EPA and the Argonne National Laboratory (ANL) have partnered to design a low cost, easily constructible technology called the Gold Shop Mercury Capture System (MCS).
Engaging in Partnerships and Consumer Outreach to Promote Voluntary Reductions in Mercury Use and Releases
• Industrial thermometers: EPA is working with the National Institute of Standards and Technology and stakeholders to reduce the use of mercury-containing non-fever thermometers in industrial and commercial settings.
• Dental amalgam: Dental amalgams are considered medical devices and are regulated by U.S. Food and Drug Administration (FDA). Since the 1990s, FDA, the Centers for Disease Control and Prevention (CDC) and other government agencies have reviewed the scientific literature looking for links between dental amalgams and health problems. CDC reported in 2001 that there is little evidence that the health of the vast majority of people with dental amalgam is compromised, nor that removing amalgam fillings has a beneficial effect on health. In 2002, FDA published a proposed rule to classify dental amalgam as a class II medical device with special controls. On April 28, 2008, FDA reopened the comment period for that proposed rule.
• Waste from dental amalgam: EPA has worked with the American Dental Association and with dental amalgam manufacturers to teach dentists and dental students best management practices for disposing of amalgam waste.
• Cultural uses of mercury: People who use metallic mercury in ethnic folk medicine and for religious practices may be at risk of exposure to mercury. Metallic mercury is sold under the name “azogue” in stores (sometimes called botanicas), which specialize in religious items used in Esperitismo (a spiritual belief system native to Puerto Rico), Santeria (a Cuban-based religion that venerates both African deities and Catholic saints), and voodoo. The use of azogue in religious practices is recommended in some Hispanic communities by family members, spiritualists, card readers, and santeros. Typically, azogue is carried on one’s person in a sealed pouch prepared by a spiritual leader or sprinkled in the home or automobile.
• Mercury-containing products: EPA advises consumers on using alternatives to products that contain mercury and on recycling and disposing of these products.
Exposures to Other Mercury Compounds (Inorganic and Organic)
Inorganic mercury compounds take the form of mercury salts. They are generally white powders or crystals, with the exception of mercuric sulfide (cinnabar) which is red. Inorganic compounds and organic compounds (such as phenylmercury acetate and ethylmercury), have been commonly used as fungicides, antiseptics or disinfectants. They have also been used in a variety of products. Most of these uses have been discontinued, but small amounts of these compounds can still be found as preservatives in some medicines. The U.S. Food and Drug Administration maintains a list of medicines that contain mercury.
Excessive exposure to inorganic and organic mercury compounds can result from misuse or overuse of mercury-containing products, especially outdated products containing more mercury. Exposure to mercury compounds is primarily through ingestion, but can occur through other pathways. Ingested organic mercury compounds are more readily absorbed through the gastrointestinal tract than are inorganic compounds.
