The EPA 2004 National Listing of Fish Advisories indicates that states reported that 395 new fish advisories were issued in 2004 and 65 previous advisories were reactivated, bringing the total number of advisories in effect to 3,221 in 2004.

Fifteen states have issued fish advisories for all of their coastal waters.

  Almost 65% of the coastline of the United States (excluding Alaska, which has no advisories) currently is under advisory. Based on coastal size estimates from the National Oceanic and Atmospheric Administration, 92% of the Atlantic coast and 100% of the Gulf coast were under advisory in 2004 as was the case in 2003.

  The Atlantic coast advisories have been issued for a wide variety of chemical contaminants, including mercury, PCBs, dioxins, and cadmium. All of the Gulf coast advisories have been issued for mercury. No Pacific coast state has issued a statewide advisory for any of its coastal waters, although several local areas along the Pacific coast are under advisory. Hawaii has a statewide advisory in affect for mercury in several marine fish species.

Bioaccumulative Contaminants 

  Bioaccumulative chemical contaminants accumulate in the tissues of aquatic organisms at concentrations many times higher than concentrations in the water. Bioaccumulative chemical contaminants can persist for relatively long periods in sediments, where bottom dwelling organisms that are low in the food chain can accumulate them and pass them up the food chain to fish. Concentrations of bioaccumulative contaminants in the tissues of aquatic organisms may increase at each level of the food chain.

  As a result, top predators in a food chain, such as largemouth bass or walleye, may have concentrations of bioaccumulative contaminants in their tissues a million times higher than the concentrations found in the waterbodies.  Although there are advisories in the United States for 36 chemical contaminants, almost 98% of advisories in effect in 2004 involved five bioaccumulative chemical contaminants: mercury, PCBs, chlordane, dioxins, and DDT.  In this regard, considerable progress has been made towards reducing theoccurrence of these contaminants in the environment.  US human-caused emissions of mercury to the air have declined more than 45% since 1990 and EPA has issued regulations that will result in further reduction of mercury emissions.  For example, on March 15, 2005, EPA issued the Clean Air Mercury Rule (CAMR) to permanently cap and reduce mercury emissions from coal-fired power plants.  CAMR supplements EPA’s Clean Air Interstate Rule (CAIR) to significantly reduce emissions from coal-fired power plants.  When fully implemented, these rules are estimated to reduce utility emissions of mercury nearly 70 percent.  In addition, production of PCBs for use ceased in 1977; chlordane was banned in 1988; DDT was banned in 1972; and known and quantifiable industrial emissions of dioxin in the United States are estimated

to have been reduced by approximately 90% from 1987 levels.

Mercury

  The total number of advisories for mercury increased from 2,362 in 2003 to 2,436 in 2004, with 44 states, 1 territory, and 2 tribes issuing mercury advisories.

  Seventy-six percent of all advisories have been issued, at least in part, because of mercury. The increase in the number of mercury advisories in2004 can be attributed to the issuance of new mercury advisories by 20 states and 1 tribe. Most of these new advisories were issued by Florida and Minnesota. To date, 44 states, 2 tribes and 1 territory have issued mercury advisories.

  Twelve states (Alabama, Florida, Georgia, Louisiana, Maine, Massachusetts, Mississippi, New Hampshire, North Carolina, Rhode Island, South Carolina, and Texas) have statewide advisories for mercury in their coastal waters. Hawaii has a statewide advisory for mercury in marine fish. The Micmac tribe of Maine has two tribal statewide advisories in effect for mercury in freshwater and marine fish (including lobster). In addition, the Cheyenne River Sioux Tribe has one tribal statewide for mercury in rivers, lakes, and stock ponds. Outbreaks of methylmercury poisoning have made it clear that adults, children, and developing fetuses are at risk from dietary exposure to methylmercury. During these poisoning outbreaks some mothers with no symptoms of nervous system damage gave birth to infants with severe disabilities and it became clear that the developing nervous system of the fetus may be more vulnerable to methylmercury than is the adult nervous system. Mothers who are exposed to methylmercury and breast-feed their babies may also expose their infant children through their milk.

  Typically, mercury is released into the atmosphere in one of three forms:

• elemental mercury: can travel a range of distances, may remain in the atmosphere up to one year and may travel globally before undergoing transformation

• particle-bound mercury: can fall out of the air over a range of distances

• oxidized mercury (sometimes called ionic or reactive gaseous mercury (RGM)): found predominantly in water-soluble forms, which may be deposited at a range of distances from sources depending on a variety of factors including topographic and meteorologic conditions downwind of a source.

   What happens to mercury after it is emitted depends on several factors:

• the form of mercury emitted

• the location of the emission source

• how high above the landscape the mercury is released (e.g., the height of the stack)

• the surrounding terrain

• the weather

   Depending on these factors, atmospheric mercury can be transported over a range of distances before it is deposited, potentially resulting in deposition on local, regional, continental and/or global scales. Mercury that remains in the air for prolonged periods of time and travels across continents is said to be in the "global cycle."

  Recent emissions estimates of annual global mercury emissions from all sources, natural and anthropogenic (human-generated), which are highly uncertain, are about 4800-8300 tons per year. U.S. anthropogenic mercury emissions are estimated to account for roughly 3 percent of the total global emissions, and the U.S. power sector is estimated to account for about 1 percent the total global emissions. EPA has estimated that about one third of U.S. emissions are deposited within the contiguous U.S. and the remainder enters the global cycle. Current estimates are that less than half of all mercury deposition within the U.S. comes from U.S. sources, although deposition varies by geographic location. For example, compared to the country as a whole, U.S. sources represent a greater fraction of the total deposition in parts of the Northeast because of the direction of the prevailing winds .

  When mercury falls in rain or snow, it may flow into bodies of water like lakes and streams. When it falls out of the air as dry deposition, it may eventually be washed into those bodies by rain. Bacteria in soils and sediments convert mercury to methylmercury. In this form, it is taken up by tiny aquatic plants and animals. Fish that eat these organisms build up methylmercury in their bodies. As ever-bigger fish eat smaller ones, the methylmercury is concentrated further up the food chain. This process is called "bioaccumulation".

  Methylmercury concentrations in fish depend on many factors, including mercury, the concentration in water, water pH and temperature, the amount of dissolved solids and organic matter in the water, and what organisms live in the water.

  Methylmercury concentrations in fish may also be affected by the presence of sulfur and other chemicals in the water. Because of these variables, and because food webs are very complex, bioaccumulation is hard to predict and can vary from one water body to another. However, in a given water body, the highest concentrations of methylmercury are generally found in large fish that eat other fish.

   In 2004, EPA and the U.S. Food and Drug Administration (FDA) issued advice for women who might become pregnant, women who are pregnant, nursing mothers, and young children. The national advice is not included in the statistics presented in this fact sheet. The following advice is still in effect: 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; therefore, women and young children in particular should include fish or shellfish in their diets due to the many nutritional benefits.  Nearly all fish and shellfish, however, contain traces of mercury. For most people, the risk from mercury from 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 FDA and EPA are advising women who may become pregnant, pregnant women, nursing mothers, and young children to avoid some types of fish and to only eat fish and shellfish that are lower in mercury.  By following the three recommendations listed below 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 consumed 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. 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 local lakes, rivers, and coastal areas.

  If no advice is available, eat up to 6 ounces (one average meal) per week of fish caught from local waters, but do not consume any other fish during that week.  Follow these same recommendations when including fish and shellfish in a young child’s diet, but serve smaller portions.

  More information on mercury and US fish stocks can be found at the conclusion of this article.

PCBs 

  In 2004, there were 873 advisories in place for PCBs, with 39 states, American Samoa, and the St. Regis Mohawk Tribe

reporting PCB advisories in 2004. This represents a decrease in the number of PCB advisories since 2003 when there were 884 PCB advisories. Although 17 states added new advisories for PCBs in 2004, 55 advisories were rescinded. There were 4,652,401 lake acres and 110,522 river miles under PCB advisory in 2004. Four states (District of Columbia, Indiana, Minnesota, and New York) issued statewide freshwater (river and/or lake) advisories for PCBs, and seven other states (Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, and Rhode Island) issued PCB advisories for all of their coastal marine waters in 2004. 

Dioxins 

  In 2003 there were 90 existing dioxin advisories. In 2004, Massachusetts issued 5 new dioxin advisories; Hawaii issued 1

new dioxin advisory; Maine added dioxin to 7 existing advisories for other contaminants; and Michigan, New Hampshire, New Jersey, Oregon, and Texas also added dioxin to existing advisories, bringing the total number of dioxin advisories to 106.   A total of 22,757 lake acres and 2,335 river miles were under a dioxin advisory in 2004. Although dioxins are one of the five major contaminants that have resulted in the issuance of health advisories, the geographic extent of dioxin advisories is extremely limited compared to that for the other four major contaminants. This is due in part to the limited monitoring of dioxins resulting from the high cost of contaminant analysis. Also, dioxins have been associated primarily with specific locations near some pulp and paper plants that use a bleach kraft process, as well as with other types of chemical manufacturing facilities or incineration facilities.

DDT  

  Although the use of DDT, an organochlorine pesticide, has been banned since 1975, there were 67 advisories in effect for DDT (and its degradation products, DDE and DDD) in 2004. In 2003 there were 52 advisories in effect. There are currently 843,762 lake acres and 69,010 river miles under advisory for DDT. California had the greatest number of DDT advisories in effect in 2004 (14), followed by Maine (13) and Massachusetts (10). During 2004, Massachusetts issued 10 new advisories for DDT, and New York had an existing statewide advisory for multiple contaminants, including DDT.  

Other Contaminants 

  Although the five bioaccumulative contaminants account for almost 98% of the total number of advisories, the remaining 2% of all fish advisories are caused by other contaminants. These include heavy metals (e.g., arsenic, cadmium, chromium, copper, lead, selenium, and zinc) and organochlorine pesticides (e.g., dieldrin, heptachlor epoxide, kepone, mirex, and toxaphene), as well as a myriad of other chemical compounds, including creosote, polycyclic aromatic hydrocarbons (PAHs), hexachlorobenzene, pentachlorophenol, and diethylphthalate.  In 2004, eight states issued new advisories for these contaminants: Delaware (not specified), Georgia (toxaphene), Indiana (not specified), Massachusetts (pesticides), Maryland (chlorinated pesticides), New York (mirex), Ohio (mirex), and Utah (arsenic). Washington also added diethylphthalate to an existing advisory. In contrast, other states rescinded advisories for aldrin, dichloroethane, gasoline, lindane, trichloroethane, and vinyl chloride. Although these other chemical contaminants represent only 2% of the total number of advisories, the extent of the area under advisory for these contaminants slightly exceeds the lake acres and river miles under advisory for DDT. In 2004, 2,176,525 lake acres and 102,938 river miles were under advisories for these contaminants. The majority of lake acres and river miles under advisory for other chemical contaminants are the result of a statewide advisory in New York for multiple contaminants, including mirex, a regional advisory in Mississippi for toxaphene, and a statewide advisory in Maine for cadmium. 

Wildlife Advisories 

In addition to advisories for fish and shellfish, the National Listing of Fish Advisories Web site also contains several water- dependent wildlife advisories. In 2004, no new advisories were issued for water-dependent wildlife. States have issued advisories in previous years that are still in effect. Four states have issued consumption advisories for turtles: Massachusetts (1), Minnesota (6), New York (statewide advisory), and Rhode Island (1). In addition, Massachusetts has an advisory for frogs; New York has a statewide advisory for waterfowl; Utah has an advisory for American coot and ducks; and Maine issued a statewide advisory for cadmium in moose liver and kidneys.