Mercury in Fish

Fish Consumption Advisories

Because fish is a lean, low-calorie source of protein, it can be an important part of a healthy diet. However, some fish may contain unhealthy levels of mercury in their tissue which can be harmful if eaten in large quantities over a lifetime. To protect the health of everyone who enjoys eating fish caught in Nevada waters, NDOW has been sampling fish tissue for mercury analysis since 2005 to determine locations where fish have high methylmercury concentrations. The samples are sent to the Environmental Protection Agency (EPA) Lab to provide mercury analysis of these fish. When a specific fish species exceeds the Food and Drug Administration (FDA) action level of 1.0 part per million mercury, there is a potential risk for the public’s health based on the amount of fish typically eaten. Based on the FDA action level, the Nevada Division of Public and Behavioral Health (NDPBH) makes recommendations on which waters warrant consumption advisories due to elevated mercury levels. NDPBH recommends limited or no consumption of fish from the following waters:

Carson River from Dayton to the Lahontan Dam and all water in the Lahontan ValleyNo consumption of any fish
Little and Big Washoe lakesNo consumption of white bass
Rye Patch ReservoirNo consumption of wipers and walleye and no more than one eight-ounce meal per week of any other fish
Chimney Dam ReservoirNo consumption of walleye
Comins LakeNo consumption of largemouth bass and northern pike

When fishing in waters where “no consumption” recommendations are in effect, pregnant women, nursing mothers and children should limit their consumption, eat smaller sized fish (rather than larger ones) or practice catch-and-release. Find advice about eating fish from the FDA and EPA here.

Fish Consumption Recommendations

NDOW also uses this data to determine safe consumption rates from other waters around the state where fish fall below the FDA action level. Click on the links below (Western, Southern, Eastern) to find the recommended consumption rate of fish from a water that you may be fishing. Consumption rates are in accordance with EPA guidelines (see EPA Publication: EPA 823-B-00-008, November 2000; guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories. Vol. 2: Risk Assessment and Fish Consumption Limits, 3rd Edition. Table 4-3.)

Typical Meal Size

An adult meal size is considered to be 8-ounces of fish meat, about the size of two decks of cards. Children should eat smaller, age-appropriate amounts.

Consider how much fish from all sources (caught and purchased) that you are likely to eat in a month and follow the recommendations accordingly. Space your meals of fish evenly during the month when eating fish that have consumption recommendations. For example, the consumption recommendation for brown trout from the Carson River near the Bryant Creek confluence is 8-meals per month. This should be spaced out to 2-meals per week, rather than eating the entire 8-meals in a few days time. Removing the skin does not decrease the amount of mercury in the edible portions.

The EPA and FDA have issued advice for pregnant or nursing mothers and children to make informed choices when it comes to the types of fish that are nutritious and safe to eat. That advice can be found here.

The bottom line is that Nevadans should feel free to enjoy fishing in the state’s waters and to enjoy fish they catch as an important and healthy part of their diet.  Generally, larger, older fish can concentrate more mercury than smaller, younger ones.  These waters still provide great fishing value, and some species are even managed for their trophy-sized quality.  It would be best to release these fish and just enjoy the experience of fishing and being in the outdoors.

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