Selenium in Seafood

What and where is selenium?

  • Selenium is an essential nutrient. Small doses are healthy and necessary, but higher doses can be toxic.Selenium represented as Se next to food items such as fish, lobster, garlic, nuts, cheese, corn, bread, and wheat.
  • Selenium is in many foods, including meat (especially organ meats), cereals, grains, and eggs, and some dietary supplements. 
  • Fish and shellfish can be excellent sources of selenium, and are part of a healthy diet.
  • Selenium is naturally present in the environment, though levels vary greatly.
  • Selenium can also build up in the environment due to human activity, such as certain agricultural practices.
  • Selenium levels in fish have not been a concern in most areas of California.  


What is the health concern for humans?

  • Too much selenium can cause health problems, such as hair and nail loss, gastrointestinal distress, dizziness, and tremors.


Should I still eat fish?

  • Yes! Low-contaminant fish are an important part of a well-balanced diet.
  • Fish are a good source of protein and vitamins, and a primary source of heart-healthy omega-3 fatty acids.
  • Eating two servings of fish per week is good for you, according to the American Heart Association.
  • If you are pregnant, eating low-contaminant fish may help your baby’s brain develop.


Can I reduce selenium levels in fish?

  • No. There is no special way to clean or prepare fish to reduce their selenium levels.


How can I reduce my risk?

  • Only eat the fish fillet (meat). Don’t eat the internal organs of fish and shellfish (“guts,” crab “butter,” and lobster “tomalley”), as these may contain other harmful chemicals.
  • If you catch your own fish, follow the Office of Environmental Health Hazard Assessment’s (OEHHA) fish advisories for California water bodies.
  • If you are on a high-selenium diet, or use dietary supplements that include selenium, pay special attention to fish advisories based on selenium.


Where can I learn more?



Fish Advisory Map

View maps of current statewide and site-specific advisories

Advisory Map

Fish, Ecotoxicology and Water Section

Sacramento Office
1001 I Street
Sacramento, CA 95814
Phone: (916) 423-7572

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