Reducing mercury emissions and implementing strategies to reduce exposure in wildlife and humans is critical to protecting the health of our oceans and the animals that rely on them. Mercury pollution poses a significant threat to marine wildlife. Humans around the world who consume contaminated seafood can be exposed to methylmercury, which can cause a range of health problems, including neurological damage, developmental delays in children, and cardiovascular disease. High levels of mercury in these types of fish can lead to developmental abnormalities, to reduced reproductive success and, in some cases, to impaired growth. Large predatory fish such as tuna and swordfish are also vulnerable to mercury contamination. High levels of mercury in these animals can lead to reproductive failure, behavioral changes, and even death. Marine mammals such as dolphins, whales and seals are particularly susceptible to mercury contamination due to their position at the top of the food chain. As larger predators consume these smaller organisms, the concentration in the body increases, a process known as biomagnification. When smaller organisms such as plankton and small fish consume methylmercury-contaminated food, the toxin accumulates in their bodies. Once there, it can be converted to methylmercury, a highly toxic form that is easily absorbed by marine organisms. Mercury can enter the ocean through a variety of sources, including atmospheric deposition, runoff from land, and industrial discharges. (2022).When mercury released into the environment, it can bioaccumulate in the food chain, with predators at the top, such as marine mammals, seabirds, and large predatory fish, being particularly vulnerable. Questions & answers from the FDA/EPA advice about eating fish for those who might become or are pregnant or breastfeeding and children ages 1 to 11 years.Mercury levels in commercial fish and shellfish (1990-2012).Health effects of exposure to mercury.

Fish and shellfish advisories and safe eating guidelines.

Dietary Guidelines for Americans, 2020-2025.

These groups should select varieties of fish that are low in mercury, including canned light tuna, and limit their intake based on the recommendations set by the FDA. However, raw fish and varieties of fish that are high in mercury, such as bigeye tuna, should be avoided in some groups, including small children and people who are pregnant, trying to become pregnant, or breastfeeding. The FDA also notes that children and people who are pregnant should avoid raw fish, as they may be at a higher risk of foodborne illness.įederal, state, and local advisories may also be issued when certain types of fish are considered unsafe to eat.Īccording to the Environmental Protection Agency, these advisories may apply to specific waterbodies or types of water and can be issued to the general public or specific populations, such as people who are pregnant or breastfeeding.Ĭertain types of tuna are high in mercury, which can have harmful effects on health in high amounts or in certain populations.įor most healthy adults, it’s recommended to consume at least 2 servings of fish per week, which can include tuna.

However, tuna also provides a wealth of nutritional content. Though these varieties of tuna are not recommended for children, those who are pregnant or breastfeeding can consume up to 1 serving per week.īigeye tuna, which is often used in sashimi and sushi, is high in mercury and is not recommended for these groups. Canned tuna is frequently a major source of mercury in the diet. People who are pregnant or breastfeeding can consume 2–3 servings of canned light tuna per week and children can consume 2 servings per week.Ĭanned, fresh, or frozen white albacore tuna and yellowfin tuna contain slightly more mercury but are also good choices. For children, 1 serving is:Ĭanned light tuna is low in mercury and is considered one of the best choices for individuals that need to limit their exposure to mercury. However, the Food and Drug Administration (FDA) recommends selecting varieties of fish that are low in mercury for children ages 1–11 and individuals who are pregnant, trying to become pregnant, or breastfeeding.įor adults, 4 oz is considered 1 serving. Recommendations for how often a person should eat canned tuna can vary depending on several factors, including the specific type of tuna, their age, and whether or not they belong to a group that may be more sensitive to the effects of mercury.Īccording to the Dietary Guidelines for Americans, most adults should aim to eat at least 8 ounces, or 2 servings, of fish per week, which can include canned tuna.

Tuna and mercury poisoning