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Page 6

Habitat destruction

By design, a broad-spectrum herbicide such as glyphosate kills most plants with which it comes into contact. In the Colombian ecosystems targeted by the spray campaigns, some of these plants are likely to be rare, endangered, and/or economically important. Furthermore, damage to plants can translate into broader ecological damage with long term consequences. For example, loss of plant cover can lead to soil erosion and drying of water courses.

Herbicide damage to plants can also affect animals, by altering the habitats on which they depend. For example, birds may be affected by the loss of trees they nest in or plants that produce edible fruit. Insects may, similarly, be affected by the loss of plants on which they depend for food or habitat. Linda Farley of American Birds Conservancy notes that the Santa Marta conure, a bird listed as "globally threatened" by Birdlife International, is found only in the Santa Marta mountains, a small area that is "almost completely encompassed within the known coca growing region," and that "herbicide-induced habitat destruction has been implicated as a reason for the bird's decline." 53 A letter to the editor from WWF notes that some regions of Colombia, such as the northern Andes, are the wintering ground of some North American migratory bird species; 54 thus, damage to habitats in Colombia can have direct adverse effects on bird populations in North America as well. A recent study of drug crop cultivation and bird populations found that some of the areas where drug crops are grown include sites of high conservation priority for endangered birds; further habitat destruction in these areas could lead to the extinction of some bird species. 55

The spray campaigns also lead to habitat loss indirectly when farmers respond to the destruction of legal or illegal crops by clearing new areas of previously undisturbed forest. A statement prepared by Earthjustice for presentation to the United Nations Human Rights Commission notes that this phenomenon has resulted in the loss of critical bird habitats. 56 The process of "'triple deforestation': sowing, spraying, and sowing again in another area," is described in detail by the office of the Colombian Human Rights Ombudsman. 57 Once coca crops have been planted, usually by settlers who have been internally displaced by conflict elsewhere in the country:58

Aerial fumigation programs for the eradication of illegal crops are established without significant controls and they affect not only the hectares of land planted with coca but also food crops and natural ecosystems. With the destruction of coca and food crops, the farmer moves not down river but deeper into the jungle, farther from the access route, the river, and starts the process over. Eradication of coca crops drives farmers deeper into the jungle, to more remote locations where they will not be found so easily, thus leading to deforestation of new parcels.59

Direct effects on wildlife

In addition to adverse effects resulting from habitat destruction, wildlife may suffer toxic effects from contact with the spray. Fish, birds, insects, and soil microorganisms are among the organisms that may be affected by the spray formulations. No studies have been conducted on effects of the specific spray formulation currently used in Colombia, or on effects of glyphosate herbicides in the specific ecosystems and under the application procedures currently being used in Colombia. However, studies conducted in other contexts show toxic effects on a wide range of organisms.

For example, studies have found that glyphosate formulations have toxic effects on aquatic organisms including fish, amphibians, insects, crawfish and water fleas.60 Glyphosate can also affect soil organisms including earthworms, fungi, and microbes. A New Zealand study showed that glyphosate significantly affected growth and survival of earthworms; 61 several studies have found that glyphosate can enhance the growth of disease-causing fungi;62 and one recent study found that glyphosate can interfere with beneficial mycorrhizal relationships between fungi and plants. 63

Effects of glyphosate herbicides can vary significantly depending on the circumstances of exposure. The U.S. Embassy states in a November, 2001 "fact sheet" that the herbicides used in the spray campaigns are "practically nontoxic to fish."64 In fact, there is reason to believe that the mixture as sprayed in Colombia can have serious adverse effects on fish life, especially since exposure circumstances in Colombia are quite different from those under which tests have been conducted. Effects of glyphosate and Roundup on fish vary widely depending on species affected, temperature, and other factors. In general, formulations including a surfactant are more toxic to fish than pure glyphosate. The toxicity of surfactant ingredients can vary according to the hardness and acidity of the water where it is sprayed. Perhaps most importantly for tropical regions, toxicity of Roundup to some fish has been found to increase with increasing water temperature.65 Little to no information is available on the likely effects of the specific exposure conditions that exist in Colombia, but it is plausible to expect that effects on fish would be more serious than is predicted based on experiences in temperate climates.

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53 Ibid. 54 Kathryn S. Fuller (President, World Wildlife Fund), "Fumigation dangers" Chicago Tribune, (July 23, 2001).

55 Maria D. Alvarez, "Illicit Crops and Bird Conservation Priorities in Colombia," Conservation Biology Vol. 16 (2002). Available at, visited February 10, 2002.

56 Earthjustice and Amazon Alliance, "Spraying Toxic Herbicides on Rural Colombian and Ecuadorian Communities," Written Statement of Earthjustice and Amazon Alliance for Agenda Item 10: Economic, Social, and Cultural Rights, United Nations Commission on Human Rights, 58th Session, March 18-April 26, 2002. Available at, visited February 10, 2002.)

57 Jose Fernando Castro Caycedo, Nelson Caicedo Rodríguez, Luis Fernando Maldonado Guerrero, and others. Los Cultivos Ilícitos, Política Mundial y Realidad en Colombia. Defensoría del Pueblo. Bogotá. August 2000. pp. 88-89.

58 Ibid.

59 Ibid.

60 See A. A. Abdelghani, "Toxicity evaluation of single and chemical mixtures of Roundup, Garlon-3A, 2,4-D, and Syndets surfactant to channel catfish (Ictalurus punctatus), bluegill sunfish (Lepomis michochirus), and crawfish (Procambarus spp.)." Environmental toxicology and water quality 12: 3 (1997), pp. 237-243; L. C. Folmar et al., "Toxicity of the Herbicide Glyphosate and several of its formulations on fish and aquatic invertebrates." Archives of Environmental Contamination and Toxicology 8 (1979), pp. 269-278; Hartman, WA and Martin, D.B. "Effect of suspended bentonite clay on the acute toxicity of glyphosate to Daphnia pulex and Lemna minor." Bulletin of Environmental Contamination and Toxicology 33 (1984) pp. 355-361; and J. A. Servizi, "Acute Toxicity of Garlon 4 and Roundup herbicides in salmon, Daphnia, and trout." Bulletin Environment Contamination Toxicology 39 (1987) pp. 15-22, cited in Jeremy Bigwood, "A Brief Overview of the Scientific Literature Regarding Reported Deleterious Effects of Glyphosate Formulations on Aquatic and Soil Biota," document prepared for the Ministry of the Environment of Ecuador, March 6, 2002. Available at, visited March 18, 2002.

61 J. A. Springett and R. A. J. Gray, "Effect of repeated low doses of biocides on the earthworm Aporrectodea caliginosa in laboratory culture." Soil. Biol. Biochem 24: 12 (1992), pp. 1739-1744, cited in Bigwood 2002, op. cit.

62 See literature review in Bigwood 2002, op. cit.

63 M. T. Wan et al., "A new technique for determining the sublethal toxicity of pesticides to the vesicular-arbuscular mycorrhizal fungus Glomus intraradices." Environ-Toxicol-Chem. 17:7 (July 1998) p. 1421-1428, cited in Bigwood 2002, op. cit.

64 Bureau for International Narcotics and Law Enforcement Affairs, U.S. Department of State, "Fact Sheet: Eradication of Illicit Crops: Frequently Asked Questions," November 30, 2001.

65 World Health Organization, International Programme on Chemical Safety, International Labour Organization, Glyphosate. Environmental Health Criteria #159, (1994). Geneva, Switzerland, pp. 110-112.