|
 Aquatic EcosystemsToxic Chemicals: Page 11Crested ibises require large trees for nesting near marshes, and to protect these birds, China enacted emergency regulations prohibiting logging in the area. Their nest is a flimsy stick platform lined with small twigs, leaves and hay, built in tree branches at heights up to 25 meters (Hoyo et al. 1992). Hunting has also been banned, and the Chinese government accorded them official protection, but some wintering birds are still shot (BI 2000). These birds declined in Japan as a result of poisoning by mercury pesticides and other agricultural chemicals applied to rice paddies. Their feeding habits make them very susceptible to poisoning from pesticides because chemicals accumulate in the bodies of their aquatic prey of crabs, frogs, small fish, mollusk and insects. For this reason, pesticides have been banned in nearby rice paddies (BI 2000). The drainage of rice fields in the wintering habitat has reduced food supply, and 80 percent of birds found dead in the wild have starved to death (BI 2000).
Gold mining has become a major peril to rivers and aquatic ecosystems. The ore is treated with cyanide or mercury to remove the gold, and the toxic waste is either flushed into waterways or accumulates in holding ponds. Cyanide is one of the most toxic of all compounds, and it has caused irreparable harm to the pristine rivers of New Guinea, South America and other parts of the world. Cyanide spills have caused massive fish kills and river destruction in Guyana (Associated Press 1995). Brazilian gold miners have illegally polluted rivers in tribal reservations in remote Amazonian forests with cyanide, destroying the entire fish and aquatic fauna upon which tribes had depended for thousands of years.
In Papua (formerly known as Irian Jaya), the western portion of the island of New Guinea governed by Indonesia, the Grasberg Mine contains the world's largest known gold deposit, an estimated 22 million ounces (Bryce 1995). This mine sits atop a peak in the Sudirman Mountains, rising nearly 16,400 feet, and provides habitat for many unique species (Whitten and Whitten 1992). The Grasberg Mine has polluted the Aikwa River, which drains the region and flows to the southeastern coast, killing fish (Bryce 1995). The mine also contains 15 billion pounds of copper and 37 million ounces of silver, for a total value of $50 billion (Bryce 1995). These ores are being mined and transported through the world's longest slurry pipeline and down the world's longest single-span cable car track to a massive mill (Whitten and Whitten 1992). The entire mountain has already been stripped, reducing it to terraced ridges, and US-owned Freeport-McMoran Copper and Gold Inc., which owns the mine, plans to drill in 75 more sites (O'Neill 1996). The company has been given access to 9 million acres (1.5 times the size of Vermont) by the Indonesian government (O'Neill 1996). French surveyors are seeking uranium in the Vogelkop, or Bird's Head, Peninsula at the far western end of New Guinea, and Australians are searching for gold in the Korowa region in east-central Papua (O'Neill 1996).
New Guinea's great biological diversity is being threatened by this mining. Beautiful birds of paradise, bowerbirds, tree kangaroos and countless other species, ancient forests and wild rivers are gradually being destroyed by mining. At present, forests cover 85 percent of Papua, and clear, free flowing rivers drain the highlands (O'Neill 1996). Much of Papua is without roads, and many areas remain unexplored. New Guinea's extraordinary birdlife is rich in species, totaling 725, more than in all of North America (Beehler et al. 1986). Tim Flannery, an Australian mammalogist, is so concerned about the destruction of this island, and the effect on native peoples, that he dedicated his book on New Guinea's wildlife to Chief Executive Officers of mining companies "in the hope that, through reading it, they will understand a little better the people whose lives they so profoundly change" (Flannery 1998). Flannery discovered an extraordinary black and white species of tree kangaroo (Dendrolagus mbaiso) in a forest not far from the mine. The mine owners built a large, dam-like structure to contain the enormous amount of mine tailings, all of which are dumped into the headwaters of the Aikwa River. The sediment builds up and smothers the roots of trees, causing vast tracts of forest to die and killing fish and mudcrabs along the coast (Flannery 1998). The tailings area will eventually be so large that it will be visible from space, and the mine has encouraged logging and other intrusions into the wilderness (Flannery 1998).
To the northwest, rivers of southern Borneo have been turned into "polluted deserts" by local people in search of gold. They clear away the rainforest, destroying banks with high-powered hoses (Mydans 1997). Mercury is used to extract the gold dust, contaminating the rivers with 100 times acceptable levels (Mydans 1997). These forests are home to endangered Orangutans and hundreds of animals and plants found nowhere else on Earth.
South America's river banks are also being ravaged by miners who use high- pressure water jets to blast apart the riversides, destroying all vegetation and habitat for endangered giant otters and water birds. Venezuela's largest mine, Minerven, near El Callao, dumps cyanide and metal particles into a man-made pond without liners or barriers to prevent seepage. Trees surrounding the pond have died, and the pond's surface has become so spongy and dense that one can walk on it (Schemo 1996a). Cyanide dumped into the waters is killing fish and poisoning manatees and other aquatic life.
|
|
