Mercury and Lake Powell Fish
Background Information on Mercury in fish direct from EPA website:
Fish and shellfish are an important part of a healthy diet. Fish and shellfish contain high-quality protein and other essential nutrients, are low in saturated fat, and contain omega-3 fatty acids. A well-balanced diet that includes a variety of fish and shellfish can contribute to heart health and children's proper growth and development. So, women and young children in particular should include fish or shellfish in their diets due to the many nutritional benefits.
However, nearly all fish and shellfish contain traces of mercury. For most people, the risk from mercury by eating fish and shellfish is not a health concern. Yet, some fish and shellfish contain higher levels of mercury that may harm an unborn baby or young child's developing nervous system. The risks from mercury in fish and shellfish depend on the amount of fish and shellfish eaten and the levels of mercury in the fish and shellfish. Therefore, the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) are advising women who may become pregnant, pregnant women, nursing mothers, and young children to avoid some types of fish and eat fish and shellfish that are lower in mercury.
By following these 3 recommendations for selecting and eating fish or shellfish, women and young children will receive the benefits of eating fish and shellfish and be confident that they have reduced their exposure to the harmful effects of mercury.
Do not eat Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury.
Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury.
Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.
Another commonly eaten fish, albacore ("white") tuna has more mercury than canned light tuna. So, when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of albacore tuna per week.
Check local advisories about the safety of fish caught by family and friends in your local lakes, rivers, and coastal areas. If no advice is available, eat up to 6 ounces (one average meal) per week of fish you catch from local waters, but don't consume any other fish during that week.
Follow these same recommendations when feeding fish and shellfish to your young child, but serve smaller portions.
1. What is mercury and methylmercury?
Mercury occurs naturally in the environment and can also be released into the air through industrial pollution. Mercury falls from the air and can accumulate in streams and oceans and is turned into methylmercury in the water. It is this type of mercury that can be harmful to your unborn baby and young child. Fish absorb the methylmercury as they feed in these waters and so it builds up in them. It builds up more in some types of fish and shellfish than others, depending on what the fish eat, which is why the levels vary.
2. I'm a woman who could have children but I'm not pregnant - so why should I be concerned about methylmercury?
If you regularly eat types of fish that are high in methylmercury, it can accumulate in your blood stream over time. Methylmercury is removed from the body naturally, but it may take over a year for the levels to drop significantly. Thus, it may be present in a woman even before she becomes pregnant. This is the reason why women who are trying to become pregnant should also avoid eating certain types of fish.
3. Is there methylmercury in all fish and shellfish?
Nearly all fish and shellfish contain traces of methylmercury. However, larger fish that have lived longer have the highest levels of methylmercury because they've had more time to accumulate it. These large fish (swordfish, shark, king mackerel and tilefish) pose the greatest risk. Other types of fish and shellfish may be eaten in the amounts recommended by FDA and EPA.
4. I don't see the fish I eat in the advisory. What should I do?
If you want more information about the levels in the various types of fish you eat, see the FDA food safety web site exit EPA or the EPA Fish Advisory website.
5. What about fish sticks and fast food sandwiches?
Fish sticks and "fast-food" sandwiches are commonly made from fish that are low in mercury.
6. The advice about canned tuna is in the advisory, but what's the advice about tuna steaks?
Because tuna steak generally contains higher levels of mercury than canned light tuna, when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of tuna steak per week.
7. What if I eat more than the recommended amount of fish and shellfish in a week?
One week's consumption of fish does not change the level of methylmercury in the body much at all. If you eat a lot of fish one week, you can cut back for the next week or two. Just make sure you average the recommended amount per week.
8. Where do I get information about the safety of fish caught recreationally by family or friends?
Before you go fishing, check your Fishing Regulations Booklet for information about recreationally caught fish. You can also contact your local health department for information about local advisories. You need to check local advisories because some kinds of fish and shellfish caught in your local waters may have higher or much lower than average levels of mercury. This depends on the levels of mercury in the water in which the fish are caught. Those fish with much lower levels may be eaten more frequently and in larger amounts.
LAKE POWELL - Current Status
Ten average-sized striped bass were sampled from Lake Powell (Navajo Canyon to Rock Creek). Mercury content was analyzed and found to average .27 ppm in the 10 fish combined. Some individuals were higher and some lower. The National average mercury level in striped bass and smallmouth bass is 0.27 ppm.
The standard for concern set by EPA is .30 ppm and greater. If fish flesh has more mercury than that a health advisory is required. Since some individual fish were found to have higher mercury levels (.57 was highest) a health advisory may be prudent. The average is lower than the advisory level so more testing will be conducted.
We did test the 38.5 pound trophy fish and found it to have a mercury concentration of 1.01 ppm. Older fish accumulate more mercury. It would be wise to use trophy fish for just that - trophies and not for consumption. Conversely, to be safe eat smaller stripers (<3 pounds) as often as desired.
I will collect many more striped bass and other fish species this November and submit those fish for further testing.
So, for now, to be wise the following guidelines are recommended: This is not a formal declaration or warning - just information until further testing is conducted.
Women who are pregnant or may become pregnant, nursing mothers, and young children are advised to avoid some types of fish and to only eat fish and shellfish that are lower in mercury. The types of fish to avoid include Shark, Swordfish, King Mackerel or Tilefish because they contain high levels of mercury. The most commonly eaten fish that are low in mercury are Shrimp, canned light Tuna, Salmon, Pollock and Catfish. Up to 12 ounces (2 average meals) a week of a variety of fish and shellfish can be eaten. Another commonly eaten fish, Albacore ("white") Tuna has more mercury than canned light Tuna. Up to 6 ounces (one average meal) of Albacore Tuna can be eaten per week.
All other healthy adults can eat fish 2-3 times each week without undue concern
Freshwater smallmouth bass and striped bass fall into the category with other fish species that are slightly below the EPA standard of concern in mercury concentration.
Fish and shellfish are an important part of a healthy diet. Fish and shellfish contain high quality protein and other essential nutrients, are low in saturated fat and contain omega-3 fatty acids. A well balanced diet that includes a variety of fish and shellfish can contribute to heart health and children's proper growth and development. Thus, women and young children in particular should include fish or shellfish in their diets due to the many nutritional benefits.
Research shows that most people's fish consumption does not cause a health concern. However, high levels of mercury in the bloodstream of unborn babies and young children may harm the developing nervous system. With this in mind, FDA and EPA designed an advisory that if followed should keep an individual's mercury consumption below levels that have been shown to cause harm. By following the advisory parents can be confident of reducing their unborn or young child's exposure to the harmful effects of mercury, while at the same time maintaining a healthy diet that includes the nutritional benefits of fish and shellfish.
We want you to continue to harvest and eat fish from Lake Powell. Don't eat fish every day but eating fish twice a week is a healthy habit. If you fall in the category of mothers and children of risk then be very cautious when planning your diet. Include some fish but do it in moderation. Healthy adults are able to eat much more fish than mothers and children.
Testimonial: There is probably no better real life example of someone that has eaten fish from Lake Powell for a lifetime than me and my family. We are healthy due in some small part because we have included fish in our diet at least twice a month and probably 4 times a month for the past 30 years.