Toxic Chemicals: Page 7 Endangered Species Handbook

Aquatic Ecosystems

Toxic Chemicals: Page 7

The rivers of Europe may be the most polluted and changed by diversion, dams and channeling in the world. The Rhine, considered the "great open sewer of Western Europe," has lost the majority of its native fish, but pollution control efforts are beginning to show results (Simons 1995). After an absence of 40 years, a single, stranded Atlantic salmon (Salmo salar) appeared after flooding of the Rhine in the Netherlands in the spring of 1995 (Simons 1995). Atlantic salmon are now being reintroduced to rivers of Europe where they have been absent for many decades. A recent report on the Rhine's cleanup status concluded, however, that although much improvement had been made, heavy metals, dioxin, chlorine compounds like PCBs, herbicides and animal manure remain in sediments and are still released along parts of the river. Common otters (Lutra lutra) in Germany have dangerous levels of toxins in their kidneys, livers and fat, and cormorants along the river are laying eggs with thin shells (Simons 1995). Every year in the European Union, 250 million tons of solid industrial waste are produced, most of which is deposited in landfills which can leech into the groundwater (Lanz 1995).

As a result of population and industrial growth, incidents of wildlife killed by pollution in Africa have become more frequent. Formerly pristine lakes in the Great Rift Valley of East Africa are breeding grounds for 80 percent of the world's flamingos. Greater and lesser flamingos by the millions nest and feed in high-altitude, briny lakes. Lakes Nakuru and Bogoria in Kenya have become polluted in recent decades by factories that emit heavy metals and other industrial wastes. People have built towns and cities along the shores that discharge large amounts of untreated sewage into the lakes. Since 1993, several mass die-offs of flamingos have occurred on these lakes. More than 50,000 flamingos died in 1993 and 1995, and two more die-offs in the summer of 1999 and early 2000 killed thousands more. There is a real possibility that the massive flocks of these beautiful pink birds, one of the Earth's great wildlife spectacles, might vanish.