New tests have found that fish caught in Maryland's rivers and lakes are frequently contaminated with toxic chemicals, prompting the Maryland Department of Environment to recommend that anglers should avoid eating some kinds of the fish they catch and limit their consumption of others.
The recommendations announced today vary widely from place to place and from one variety of fish to another. In some cases - such as white perch caught in the Elk, Magothy or Back rivers - the state is advising anglers not to eat any of their catch.
FOR THE RECORD - An article in Thursday's editions of The Sun about new fish-consumption advisories in Maryland incorrectly said the state recommends that people not eat certain fish if they came from any of the state's lakes or reservoirs. In fact, the Department of the Environment recommends limiting meals of five species if caught in a lake - smallmouth bass, largemouth bass, northern pike, pickerel or walleye - but does not urge avoiding them completely. The Sun regrets the error.
In other cases - like blue crabs taken from the Patapsco River and Baltimore Harbor - the state recommends that people limit the amount they eat.
MDE officials stressed that the recommendations do not amount to a ban on fishing, and that a single serving of Maryland fish or shellfish will not harm anyone.
"This is absolutely not in any way an acute concern like a poison," said Dr. Richard Eskin, who supervised the recent testing for MDE. "The concern here is the cumulative impact [of small amounts of the chemicals] over essentially half a lifetime."
The state's advisories also do not apply to fish bought in markets or restaurants, which come from a wide variety of places.
The recommendations are based on chemical analyses of fish caught by MDE last fall in a variety of sites, from the Pocomoke River to Lake Roland. They are also based on a new estimate of the average person's fish consumption. The U.S. Environmental Protection Agency once estimated that the average person eats 7 ounces of fish a month, but that number was recently increased to 19 ounces a month.
As a result MDE is drastically expanding on its old fish consumption advisories, which used to cover only Baltimore Harbor, the Patapsco River, Lake Roland and the lower Potomac River.
MDE tested more than a dozen rivers, and in every one of them, at least one variety of fish or shellfish was contaminated enough to warrant a consumption advisory. Similarly, the agency tested 14 kinds of fish and shellfish, and all but one of them were considered unsafe for regular consumption in at least one of the rivers where they are commonly caught.
The lone exceptions were oysters, which were safe to eat everywhere the agency tested them.
The advisories do not apply to fish caught in the open waters of the Chesapeake. Testing of fish from the bay is under way and should be finished in about a year, MDE officials said.
Environmentalists and independent bay scientists praised MDE's work, but many said the tests show that certain toxic chemicals are more widespread in the area than most people thought.
"What this tells us is that wherever scientists look for toxic chemicals in the bay watershed, they're likely to find them," said Will Baker, executive director of the Chesapeake Bay Foundation.
MDE officials are launching a campaign to spread the word.
"The folks who are really going to be affected by this are people who are regularly fishing locally and eating their catch," said MDE spokesman John Verrico.
The agency plans to post signs in places where it recommends an outright ban on eating the fish or shellfish caught there, Verrico said. The Maryland Department of Natural Resources will also include the new advisories in the information that comes with a state fishing license.
Although no one is sure exactly which Marylanders catch and eat the most local fish, state experts assume that poor people fishing for food in urban areas like Baltimore, where the contamination is highest, are at the greatest risk.
The state health department will brief local health officials to get the word out, said Bonnie Birkel of the Maryland Department of Health and Mental Hygiene.
In the Baltimore area, MDE advises people not to eat channel catfish, American eel, brown bullhead or white perch caught in the Back River, the Patapsco or most of the Inner Harbor.
The agency advises that children should eat no more than four blue crabs a month from the Middle and Northwest branches; adults should eat crabs from those waters no more than twice a month; and no one should eat those crabs' yellow "mustard" because those organs collect toxic chemicals.
MDE also recommends that people should not eat any largemouth or smallmouth bass, walleye, pike or pickerel caught in any lake or reservoir in the state.
In the recent tests, the bass carried high levels of mercury. MDE staffers didn't catch any walleye, pike or pickerel last fall, but they're basing their recommendation to avoid those fish on earlier tests that showed elevated levels of mercury, Eskin said.
The chemicals causing problems are common and persistent ones: mercury, polychlorinated biphenyls or PCBs, and a group of pesticides including DDT and chlordane, which were banned in the 1970s and 1980s because of their toxic effects.