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 Aquatic EcosystemsToxic Chemicals: Page 3 Within the past few decades, an increasing toll of wildlife has been taken by toxic chemicals in aquatic environments. Massive seal kills have occurred in the North Sea, and in January 1996, the body of an endangered sperm whale (Physeter catodon) washed up on a Danish beach. Analyses of its tissues revealed dangerous levels of heavy metals – so much mercury and cadmium that the intestine had to be buried at a special dangerous waste site. The amount of toxic cadmium was 20 times higher and the quantity of mercury double that normally found in fish. The North Sea has become extremely polluted, laden with toxic chemicals from industry and untreated sewage.
Off the west coast of Mexico, a large number of dead dolphins and Gray Whales have washed ashore since 1997. Some were the apparent victims of cyanide poisoning. Drug traffickers use a cyanide-based chemical to mark ocean drop-off sites, and this chemical is thought to be responsible for poisoning these and hundreds of other marine mammals and fish. Some Gray Whales that wash ashore may be suffering other maladies related to toxic chemicals or contamination, combined with a lack of food. Numbers have risen off U.S. coasts: 278 in 1999, more than 300 in the first half of 2000 (White 2000b). The number of Gray Whale calves also declined from 1,520 in 1997 to 282 in 1999 (White 2000b). Many of the dead whales were emaciated.
Very high levels of methyl mercury have been detected in the Everglades. A study by Greenpeace found that this highly toxic metal was emanating from trash incinerators operating on the East Coast. Endangered Florida Panthers (Felis concolor coryi) have been found dead with toxic levels of mercury in their bodies. These endangered cats, an unusual subspecies of the Cougar, are close to extinction, with a population of fewer than 30 animals. Mercury is also present in sewage sludge, much of which is spread on land as fertilizer. In one year alone, 1996, the state of New Hampshire spread 1.6 tons of mercury on land (Giordano 1998). Their dairy farms are among the users of sludge obtained from chemical treatment plants in Massachusetts and other states (Giordano 1998). Common Loons, known for their haunting cries once heard in virtually every one of New Hampshire's thousands of lakes, have declined precipitously in recent years, their bodies laden with very high levels of methyl mercury (Giordano 1998).
In spite of the clear danger presented by mercury, little has been done to limit its use and disposal. Only Vermont has passed legislation that bans disposal in landfills and requires labeling of products such as fluorescent light bulbs, light switches, batteries for hearing aids and watches and thermometers. Mercury is also used in dental fillings. Boston banned the sale of household mercury thermometers in 2000, and the ban is expected to be extended statewide in 2001 (Daley and Kremmer 2001). Several other states are considering legislation to require labeling of mercury-containing products and banning their disposal by flushing or placing in the trash. New York State proposed legislation in 2001 that would eliminate the use of mercury in such products beginning in 2004 (McKinley 2001). The Environmental Protection Agency and the New York Department of Environmental Conservation began to cooperate in regulating mercury sent into the air by incinerators five years ago, but coal-burning power plants, which emit about 30 percent of all mercury emissions, are not subject to any federal or state restrictions (McKinley 2001).
Toxic mercury residues from metals companies is often shipped out of the country to nations that accept them. Now, however, some countries are unwilling to allow such shipments. One cargo ship headed for Bombay, India, in January 2001, carrying 20 tons of mercury reclaimed from a Maine factory, set off a tempest of protests by environmentalists in that country who denounced the "toxic trade" (Daley and Kremmer 2001). At least 12 factories in the United States have stocks of tons of mercury, some of which is used in a chemical process to produce chlorine (Daley and Kremmer 2001). India is a major user of industrial mercury as well, but resents becoming a dumping ground for other countries (Daley and Kremmer 2001).
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