Summer Fun Series: Are the fish you caught safe to eat?

Fishing is a pastime as old as time itself, and fish can be a substantial part of a healthy diet. However, the catch from your recreational fishing (“sportfish”) may not always be safe to eat. Fresh water sources are more likely than remote marine waters to contain harmful chemicals, due to human activities and contamination.

Sportfish Advisories

Fishing is popular in New York state, with 2.6 million acres of water on Lakes Erie, Ontario, and Champlain; 0.75 million acres on smaller lakes; 70,000 miles of streams and rivers; 150 miles of the Hudson River estuary; and 1.1 million acres of marine waters. This is why the New York State Department of Health issues health advisories for people fishing in any of these bodies of water.

In general, the Health Department recommends that people limit consumption of fish from both fresh water sources and marine water near the mouth of the Hudson River to four half-pound meals each month.

Unfortunately, there are some bodies of water in New York from which it’s advised not to eat any fish at all, or that you should eat only very limited amounts. If you’re heading out to fish, check here before you go to see whether and how much fish you should eat from those waters. This doesn’t mean you need to give up fishing in local waters altogether, but you might want to consider a policy of “catch and release” just to be on the safe side.

Contaminants found in fish

Mercury and PCBs are the primary contaminants found in fish in New York state. Local fish can also contain cadmium, chlordane, DDT, dieldrin, dioxin, and mirex. If enough of these contaminants are consumed, they will build up in your body over time. Sometimes, the effect is no more than small changes in your health that are hard to even notice, but they can lead to birth defects and cancer. Women who are beyond childbearing age and men face fewer risks from contaminated fish than do children or women who may still have babies.

Mercury is a substance that occurs naturally in the environment, but can also be released into the air from industrial pollution. When it falls from the air, it accumulates in streams, oceans, and other bodies of water and turns into methylmercury. As fish feed, they absorb methylmercury and it builds up in their bodies. Some fish absorb more methylmercury than others, based on what each type of fish eats. As humans eat certain types of fish that have higher levels of methylmercury, it builds up in our bodies, too.

PCBs (polychlorinated biphenyls) are man-made chemicals that were banned in the 1970s. However, they continue to be a fish contaminant. Studies have shown that older adults with higher levels of PCBs in their bodies could have decreased memory and learning, and there are known negative effects of PCBs on human reproduction, both with respect to sperm quality and pregnancy/menstrual cycles. There is research that indicated that high levels of PCBs might cause cancer in laboratory animals, but there are not yet adequate studies to show whether this is the case for humans.

Fish that is sold in restaurants or stores is regulated by the U.S. Food and Drug Administration (FDA), and commercial fish usually has lower concentrations of contaminants than do sportfish, so it can be safer to eat.

Pregnant women and mercury

Mercury is of particular concern to pregnant or breastfeeding mothers or women who become pregnant after eating highly contaminated fish. The chemicals have been found to have greatest effects on unborn babies and in young children and can lead to slowed brain development, learning disabilities, and negative effects on the nervous system. The chemical can be passed from mother to child through breastmilk, as well as during pregnancy.

Pregnant women should eat no more than 12 ounces of low-mercury fish (shrimp, canned light tuna, salmon, pollock, catfish) per week. High-mercury fish, especially shark, swordfish, king mackerel, and tilefish, should be avoided.

References: New York State Department of Health, U.S. Food & Drug Administration, United States Environmental Protection Agency