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Imperilled Riches HYDROELECTRIC PROJECTS Large hydroelectric projects, funded by international aid and development organizations like the World Bank, have lead to widespread forest loss in recent years. Besides inundating large tracts of rainforest (dams in the Amazon are ecologically inefficient because large tracts of forest are flooded due to the flatness of the basin) and killing off local wildlife, the dams have the effect of destroying aquatic habitats and affecting fish populations, displacing indigenous peoples, and adding carbon to the atmosphere (as the submerged wood rots). On top of the ecological damage, several projects have silted up from the erosion caused by deforestation, rendering the damns inefficient. The reduced water flow downstream disturbs riverbeds and affects floodplain farmers who rely on seasonal floods for nutrients to enrich the soil and kill pests. Thus they may turn to pesticides and artificial fertilizers which have their own negative environmental effects. Deltas experience a greater influx of salt water, effecting coastal ecosystems essential to fisheries. Hydroelectric projects are also of concern from a health standpoint because they provide opportunities for the spread of disease carrying organisms including snails (belharzia) and mosquitoes (dengue fever, yellow fever, malaria). Although "mega-projects" in Latin America are today facing more opposition and being reexamined by the sponsoring parties, hydroelectric projects in Asia are skyrocketing. On the Mekong alone, one of tropical Asia's biologically richest rivers, some 17 of dams are planned, while 54 hydroelectric projects are in the works for the Mekong Basin. POLLUTION Forests around the world are increasingly affected by air and water pollution, produced from industrial and commercial activities. Besides the pollution caused by oil spills, toxic by-products, and mining accidents, rainforests are seriously degraded by air pollution. Brazil's Atlantic forest was widely damaged in Cubatao (Sao Paulo state) during the 1970s and 1980s. Acid rain, expected to increase dramatically in the tropics in the coming years, also takes its toll on tropical forests. 15% of the world's remaining tropical forests may soon be affected by acid rain. Similarly, a vast area of forest will be adversely affected by UV-B radiation, should the ozone hole continue to expand. The dumping of trash and human waste into tributaries from overcrowded cities has resulted in serious pollution in many tropical countries. The rivers are no longer safe for human use and plant and animal life are adversely affected. HUNTING/POACHING While not responsible for deforestation, hunting and poaching cause damage to the rainforest ecosystem by removing species key to the system's functioning. The loss of a certain single species can mean extinction for many others. The wildlife harvest takes a staggering number of animals: every year in the Brazilian Amazon alone, 9.6 to 23.5 million mammals, birds, and reptiles are harvested. The annual harvest in the tropical forests of Africa may be 6-12 times that amount. Almost everyone knows the story of the tiger, its number now severely reduced thanks to the Chinese demand for traditional medicinal potions and widespread habitat loss. Illegal poaching in Africa is rampant to provide meat for poor rural and urban dwellers. In Brazil, Colombia, Nigeria, Madagascar, and other countries, the collection of wild animals for the pet trade takes its toll on local animal populations. Although such collection can be done in a sustainable manner, it is rarely done so. Reptiles are the fourth biggest commodity after drugs, diamonds, and weapons in the world smuggling trade. Sadly, less than 10% of all animals exported illegally make it to their final destination - usually a small, dirty aquarium - alive. The economic problems of Southeast Asia in the late 90s stimulated an increase in the harvest of wildlife. INTRODUCTION OF ALIEN SPECIES While not directly responsible for deforestation, the introduction of foreign plants and animals can cause severe damage to the rainforest ecosystem, especially in delicate ecosystems like islands. These feral species bring new diseases and compete with local species. The bird life of Guam and Hawaii have suffered from the introduction of alien species. In the case of Guam the culprit was a snake, while in Hawaii the mosquito and domestic chickens were responsible for decline of native birds. Since the arrival of the Polynesians, at least 62 endemic bird species have disappeared. Even more startling is Hawaii has more alien plant species than native ones. Alien weeds can choke out endemic plants, especially under disturbed forest conditions like agricultural clearing. Additionally, alien species can wipe out endemic keystone species that play an important role in the ecosystem, like pollinating certain tree species. The elimination of such an endemic species can spell the end for the tree species and a host of other dependent plant and animal species. TOURISM Tourism can have very negative environmental and social effects on the rainforest and its inhabitants. The growing interest in travel to developing countries has spawned a boom in the construction of resorts and hotels on rainforest and mangrove forest lands. Demand by these hotels for tropical hardwood provides another market for woods logged from primary rainforest. Some hotels lack proper waste management and send sewage and trash a few hundred yards off shore where it kills coral reefs and strangles sea animals. Tourists and their money can have profound social effects on local and indigenous communities. In vying for tourist dollars, traditions are forgotten and conflicts arise between members of the community. In some areas, poor villagers turn to prostitution to earn cash from tourists. If tourism is going to provide long term benefits to local people it must be sustainable. |
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