Fish Tissue

The Dietary Guidelines for Americans encourages everyone to make every bite count by following a healthy dietary pattern at every life stage. It is never too early or too late to eat healthy.

Recommendations for eating fish are:

•  At least 8 ounces of seafood (less for children) per week based on a 2,000 calorie diet.
• Those who are pregnant or breastfeeding consume between 8 and 12 ounces per week of a variety of seafood from choices that are lower in mercury.

Moderate scientific evidence shows that eating fish during pregnancy can help your baby’s cognitive development. Fish are part of a healthy eating pattern and provide key nutrients during pregnancy, breastfeeding, and/or early childhood to support a child’s brain development: 

• Omega-3 (called DHA and EPA) and omega-6 fats
• Iron
• Iodine (during pregnancy)
• Choline (also supports development of the baby’s spinal cord)

Fish also provide iron and zinc to support children’s immune systems. Fish are also a source of other nutrients like protein, vitamin B12, vitamin D, and selenium.

Strong evidence shows that eating fish, as part of a healthy eating pattern, may have heart health benefits. Healthy eating patterns that include fish may have other benefits too. Moderate scientific evidence shows that eating patterns relatively higher in fish, but also in vegetables, fruits, legumes, whole grains, low or non-fat dairy, lean meats and poultry, nuts, and unsaturated vegetable oils, and lower in red and processed meats, sugar-sweetened foods and beverages, and refined grains are associated with:

• Promotion of bone health – decreases the risk for hip fractures **
• Decreases in the risk of becoming overweight or obese **
• Decreases in the risk for colon and rectal cancers **

** There is moderate scientific evidence of a relationship between the eating pattern as a whole and the potential health benefit.

In nearly all cases, Iowa fish are safe to eat. Cleaning and/or preparing the meal cause most of the problems regarding taste or color of fish. Like all living creatures, fish are susceptible to diseases, parasites, and other naturally occurring conditions in the water. If you suspect your fish is affected by any of these conditions, do not eat it.

Consider eating smaller and younger fish which usually have lower levels of contaminants than larger ones. Most contaminants accumulate in larger, older fish.

Iowa has two waterbody specific consumption advisories for all Iowans for polychlorinated biphenyls (PCBs). These consumption advisories were issued based on advisory levels developed by HHS based on EPA and FDA guidance.

Avoid eating more than 1 serving per week of the fish from these areas: 

• Channel Catfish (all sizes) - McKinley Lake (Union County)
• Common Carp (bigger than 20 inches) - Mississippi River, Pool 15 at Davenport (Scott County)

The Iowa Department of Health and Human Services (DHHS) and the Iowa Department of Natural Resources (DNR) have issued advice for eating Iowa caught fish for women who might become or are pregnant or breastfeeding and children under 12 years of age. Additional guidance from the  United States Environmental Protection Agency (EPA) and the United States Food and Drug Administration (FDA) can help these women and parents or caretakers make informed choices about the types of fish that are nutritious and safe to eat.

Choose a Variety of Fish that are Lower in Mercury

While it is important to limit mercury in the diets of those who are pregnant or breastfeeding and children under 12 years of age because of its potential effect on developing brains, many types of fish are both nutritious and lower in mercury. Eating a variety of fish is better for you and your child than eating the same type of fish every time.

This chart can help you choose which fish commonly caught from Iowa waters to eat, and how often to eat them, based on their mercury levels. The information is based on thousands of fish tissue samples that were collected during a five-year research study in Iowa. It updates and replaces the DNR’s previous waterbody specific mercury advisories to be more protective of the health of new and expecting mothers and young children.

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Use the EPA-FDA chart for non-Iowa fish that you may purchase from the store. These charts make it easy to choose dozens of healthy and safe options for the affected segment of people and include information about the nutritional value of fish. A set of frequently asked questions and answers on the FDA website provides more information on how to use their charts and additional tips for eating fish.

Serve children 2 servings of fish a week from the “Best Choices” list. If you eat fish that are not in these charts and there is no advisory listed from where it was caught (if outside of Iowa), eat only one serving and no other fish that week.

This advice supports the recommendations of the Dietary Guidelines for Americans, 2020-2025, which reflects current science on nutrition to improve public health.

• Iowa Dept of Natural Resources - Developing Statewide Consumption Guidelines for Iowa Sport Fish
• EPA-FDA - Advice About Eating Fish and Shellfish

Iowa conducts fish tissue monitoring to supplement other environmental monitoring programs and protect the health of people eating fish from Iowa waters. Since 1977, the Iowa Department of Natural Resources (DNR) has conducted annual statewide collections and analyses of fish for toxic contaminants. From 1983 to 2013, this monitoring effort was known as the Regional Ambient Fish Tissue Monitoring Program (RAFT).

Beginning in 2014, the Iowa Fish Tissue Monitoring Program (IFTMP) became the statewide contaminant monitoring program. Historically, data generated from the IFTMP enabled DNR to document temporal changes in contaminant levels and identify lakes and rivers where high levels of contaminants in fish potentially threaten the health of those consuming Iowa caught fish (see the 2006 DNR Fish Tissue Monitoring Fact Sheet). 

DNR concentrated on mercury sampling only from 2017-2021 to establish statewide length-based mercury consumption advisory levels. Status and trend monitoring resumed in 2023.

All RAFT/IFTMP results are available in AQuIA - DNR's online water quality monitoring results database

Annual IFTMP reports are available online:

• 2021 IFTMP Report
• 2020 IFTMP Report
• 2019 IFTMP Report
• Find Previous Reports at the State Library of Iowa