Risks to ecosystems

(Excerpt from: Land-Speed-Trials: Winners and Losers in the Biotechnology Race. At URL: http://www.acephale.org/bio-safety/l-s-t_index.html
Prepared for the Institute for Agriculture and Trade Policy, Minneapolis. 13 January 1997; revised 14 March 1997)

By Michael F. Lane.

Probably more has been written about the risks biotechnology poses to ecosystems than on any other non-technical aspect of biotechnology. Rissler and Mellon (1996) offer the best overview. I will try not to repeat too much of what they have detailed. Risks to ecosystems are, of course, eventually risks to human health--and health is something that none of us wants to lose. Importantly, ecosystems also comprise agricultural land.

Genetically engineered organisms pose the greatest risks to ecosystems, since they can become dynamic living parts of them. The major application of agricultural biotechnology is the creation of crop plants which are tolerant to specific herbicides. In the United States, herbicide-tolerant crops account for about 40% of all biotechnology field tests, and in the industrialized world they account for about 57% (Rissler and Mellon 1996). For example, Calgene created a variety of cotton engineered to resist the effects of Rhône-Poulenc's Bromoxynil. Bromoxynil has been shown to cause birth defects in animals and has been categorized as toxic to human physical growth and development (Rissler and Mellon 1993). Another example, already mentioned in the previous section, is Monsanto's Roundup Ready line of crop plants. Monsanto's arguments that such crops will cut down on wasteful and possible harmful use of their herbicide do not preclude the possibility of an expanded and secured market for Roundup, which would increase its overall use. Monsanto maintains that Roundup is not harmful to human health if applied properly, and that it does not linger in the environment. Nevertheless, the long-term effects of prolonged exposure to concentrations of the herbicide are unknown.

A great number of crop plants are being engineered for the capacity to persist in marginal environments and to propagate quickly. Both these traits confer to plants the potential to become noxious weeds, overrunning human and nonhuman ecosystems, displacing and killing plants and animals, upsetting the food chain, and permanently altering habitats. Furthermore, there is the risk that these "weedy" characteristics could be passed on to wild relatives of crop plants by gene "introgression": the flow of genes from one plant species to another, mainly through cross-pollination (Rissler and Mellon 1996). This could have devastating consequences, considering that some of the weeds most pernicious to agriculture worldwide are species of the oat, barley, potato, mustard, carrot, and sorghum genera (Juma 1989). Invasive and persistent natural alien species in the U.S., such as kudzu and the paper bark tree, cost the tens of millions of dollars in control measures (Rissler and Mellon 1996).

Virus hazards

Some crop plants have been engineered with viral-coat protein genes as mechanisms of resistance to viruses. The viral genes inserted into these plants could give rise to new viruses, through natural genetic recombination and other molecular biological processes already observed in genetically engineered plants. New viral pathogens could have an enormous impact on economically important crops, requiring considerable control costs (Rissler and Mellon 1996).

Problems with Insect pests

The use of genetically engineered Bt crop plants, mentioned above, may increase the resistance of insect pests to the insecticide. If the Bt gene is spliced into a number of different plants, chance of widespread resistance is multiplied (Rissler and Mellon 1996). Dow-Elanco, Ciba-Geigy, Monsanto, and Zeneca are among companies researching and developing a range of Bt crop plants, including maize and cotton. (Anonymous n.d.). Widespread resistance would have a detrimental impact on organic and low-input farming, which rely on the Bt toxin in its naturally occurring bacterial form (Rissler and Mellon 1996). Monsanto's Bt-engineered "Bollgard" cotton was grown on nearly two million acres of U.S. farmland in 1996. Insect pests made major inroads against this crop, leading many to doubt the efficacy of genetically engineered "bio-pesticides" (Fox 1996a).

Of great concern also is the way in which genetically engineered crops--like their Green Revolution predecessors--are being designed solely for high marketable yield (grain, fruit, oil, etc.), which requires heavy doses chemical fertilizers and commensurate excessive use of water, ultimately resulting in contaminated and degraded soils and water shortages. (See Shiva 1991 for an overview.) In addition, since genetically engineered crop plants, like conventional hybrids, are designed to yield a uniform product--a commodity of known value--their promotion will aggravate the already accelerating worldwide "genetic erosion," by which traditional cultivated varieties, with greater genetic diversity and potentially desirable traits, are displaced and eradicated (Rissler and Mellon 1996).

All these ecological risks are felt most poignantly in centers of crop diversity--regions in which the greatest genetic and specific diversity of crop plants exists, in the form of wild relatives and cultivated varieties. Although the major crop plants of the U.S. have centers of diversity in other countries, the U.S. is still the center of diversity of such significant crops as cranberries, sunflowers, pecans, black walnuts, and muscadine grapes, among others (Juma 1989; Rissler and Mellon 1996).

Plants are not the only organisms that might threaten ecosystems. Genetically engineered microorganisms (GEMs) are being developed for increased frost resistance in plants, enhanced nitrogen fixation, and bio-remediation (Juma 1989). The genetically engineered bacterium Klebsiella planticola has been used for R&D in the last of these areas. When this GEM was tested in complex soil microcosms (self-contained units with field conditions, incubated in growth chambers), it killed wheat planted in the units. Microcosms containing the "parent" bacterium and experimental controls with no added bacteria had no noticeable effect on wheat. The engineered K. planticola was tested under several different environmental conditions, and the mechanism by which the wheat was killed or negatively affected differed from case to case. Furthermore, a variety of K. planticola engineered to turn crop waste into ethanol was found to have an unexpected side-effect: The GEM cut in half the amounts of mycorrhizal fungi in the soil, crucial for nitrogen fixation. If such a GEM survived readily and spread widely, it could entail expensive control measures (Holmes and Ingham 1994).

"Higher" animals are also being engineered for various purposes. They include insects, mice, and fish. The genetic engineering of fish, in particular, raises serious ecological issues. Although people around the world have practiced aquiculture on a small scale for centuries, fish remain relatively undomesticated. Unlike cows and other livestock, they can survive and breed in nature. They are also capable of traveling far and invading new ecosystems. Since fish inevitably escape from ponds and sea pens, genetically engineered varieties could multiply and out-compete endemic species. Genetic engineering of fish is moving ahead rapidly; some companies hope to begin selling fast-growing salmon to fish farmers in a few years (Anonymous 1995). Meanwhile, there is no comprehensive regulation in the U.S. governing genetically engineered animals--not even the requirement to notify the public of releases (Kapuscinski and Hallerman 1990; Mellon, pers. comm.).

Transboundary movement of the products of biotechnology is also a profound concern. Not only will genetically engineered compounds and organisms be transported deliberately across international borders in the course of trade, but engineered, self-propagating organisms will spread wherever the ecological conditions are suitable. It should be needless to say that natural phenomena do not respect social categories. Therefore, it is worrisome that currently no comprehensive, legally binding international regulation of the unique products of modern biotechnology exists. Attempts to establish such, as a protocol to the CBD, have been frustrated by the governments of industrialized countries and their supporters in the biotechnology industry. This ranks among the major political setbacks in countering the furious growth of the biotechnology industry.

References

Holmes, T.M. and E.R. Ingham. 1994. The effects of genetically engineered micro-organisms on soil food webs. In Supplement to the Bulletin of the Ecological Society of America (Abstracts of the 79th Annual ESA Meeting; Science and Public Policy, Knoxville, TN, 7-11 August 1994).

Juma, C. 1989. The Gene Hunters: Biotechnology and the Scramble for Seed.Princeton: Princeton University Press.

Kapuscinski, A.R. and E.M. Hollerman. 1990. Transgenic fishes (AFS Position Statement). Fisheries, 15(4): 2-5.

Rissler, J. and M. Mellon. 1996. The Ecological Risks of Engineered Crops. Cambridge, MA: MIT Press.

Shiva, V. 1991. The Violence of the Green Revolution: Third World Agriculture, Ecology and Politics. London: Zed Books Ltd.