Mercury in fish

May 5, 2018 Facebook Twitter LinkedIn Google+ Fishing and boaing news,Fishing and boating tips

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Mercury in fish can be a serious health problem, but fish and shellfish are an important part of a healthy diet. It is a serious problem for women who are pregnant. There are different recommendations for various species of fish. Some fish should not be eaten at all and others should be limited in consumption.

Seafood is an important part of a healthy diet. It is an important source of great protein and omega 3 fatty acids. All seafood will likely contain some mercury. This is not a problem for most people, but it can be problematic for young children and pregnant women.

12 ounces of seafood per week is considered a healthy and safe amount. In general domestic caught or raised is lower in mercury than imported fish. Smaller species of fish have less mercury than large species. This is because the large predators eat the smaller fish ingesting their mercury. The mercury levels then build up in the flesh. It will also accumulate in human flesh over time.

An interesting fact is that fish sticks and fast food fish sandwiches are generally made from fish low in mercury.

Effects of Mercury

Mercury in fish and other sources of mercury are very toxic. Mercury was widely used in industry and medicine at one time. A lot of the mercury found in fish is residue from these past actions. The mercury in fish is mostly Methylmercury.

The effect on the body depends on several things:

  • age of patient, newborns and fetuses are most affected
  • the amount of mercury involved
  • the health of the person.

Mercury has effects on the nervous system and can poison the kidneys. It will affect brain development in young children and fetuses. Most people have low amounts of methylmercury in their systems below the levels to cause adverse effect.

EPA estimates that hat more than 75,000 babies are born each year with a greater risk of learning disabilities because of their mothers’ mercury exposure

Some of the symptoms of mercury poisoning are:

  • loss of peripheral vision
  • “pins and needles” feelings, usually in the hands, feet, and around the mouth
  • lack of coordination of movements
  • impairment of speech, hearing, walking
  • muscle weakness
Children exposed to methylmercury while they are in the womb can have impacts to their:
  • cognitive thinking,
  • memory,
  • attention,
  • language,
  • fine motor skills, and
  • visual spatial skills.

Fish lowest in Mercury

These fish should be limited to 36 ounces a week for adults and 18 ounces for children. The suggested fish are:

  • Alaskan and wild salmon
  • Wild shrimp and US farm raised
  • Sardines
  • Tilapia
  • Scallops
  • oysters
  • Domestic squid

Clams and anchovies may be ok but not fully tested.

Low Mercury Fish

These fish are considered safe at 18 ounces a week for adults and 6 ounces for a child.

  • Flounder and sole
  • Haddock
  • Pollock
  • Catfish
  • trout
  • Atlantic Mackerel
  • Atlantic Croaker
  • Mullet
  • Crawfish, domestic
  • Crab

Fish to avoid

King mackerel, marlin, orange roughy, shark, swordfish, tilefish, some tuna, and bigeye tuna all contain high levels of mercury. Tuna is the largest source of mercury because of quantity of canned tuna eaten. Light or skipjack are the lowest in Mercury. Albacore tuna should be avoided in children and young women.

Fish to eat in limited quantities

Grouper, Chilean Seabass, bluefish, Halibut, black Cod, Guld Spanish Mackerel, and fresh tuns.

For further information about the risks of mercury in fish and shellfish call the U.S. Food and Drug Administration’s food information line toll-free at 1-888-SAFEFOOD.



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