GM Issues....Environment

General

The Advisory Committee on Releases to the Environment (ACRE) approves GM crops by assessing both direct and indirect impacts on the environment (cf Pesticides Approval).

Farm Scale Evaluations (FSE) in 2003 measured the effects of three GMHT (GM Herbicide Tolerant) crops on biodiversity.

Biodiversity

The FSEs showed that the GMHT rape and beet crops had "adverse effects on arable weed populations". In contrast, GMHT maize, grown and managed as in the FSEs, would not result in adverse effects. However,the herbicide used in this management regime was atrazine - soon to be banned in Europe. Latest

Cross Pollination

Cross pollination of GM crops with conventional crops is inevitable. Bees fly 10 kilometers cross pollinating as they go. Pollination by wind can be as far as 250 kilometers. Spills and seed transfer from tractors, harvesters and merchants add another dimension to distribution.

The GM genes are usually 'dominant' genes - in order to impress the desired characters. Cross contamination is inevitable. There are already examples of plants near GM Crops picking up the altered genes.

Resistance

There are examples of genes built into some crops to provide resistance to weedkillers that have jumped into weeds - thus giving them the same resistance! For latest list of herbicide resistant weeds. The main funding body for UK plant science considers that these "superweeds" are not much of a problem. More details on 'herbicide tolerance'. The mainconcern is that growing "herbicide - resistant" crops year after year encourages resistance to build up.

There is also insect resistance. Insect resistance genes in GM crops may cause adverse effects on non-target insects. Predators or parasitoids which feed on the pest may be affected indirectly when feeding on prey or hosts which contain the toxin after feeding on the GM plant.

Pesticides

One claim made for GM crops is that they will reduce pesticide use. They do and they don't. In November 2003 a US study of overall levels of pesticide use on GM corn (ie maize), soybeans and cotton reports that the GM varieties have risen.

  • Use of Bacillus thuringiensis (Bt) transgenic varieties reduced pesticide use by an estimated 19.6 million pounds in the past eight years,
  • Herbicide tolerant crops have been responsible for the application of an estimated 70 million additional pounds of pesticides.

Overall, it is estimated that GM crops are causing 50 million additional pounds of pesticides to be used in U.S. agriculture, according to a report from Institute of Science in Society

Practical experience also indicates that GM crops require more pesticides than their convential counterparts, according to the chair of the Small & Family Farms Alliance.

Contamination

According to (ACRE), toxins in the 'bt maize' pollen (corn with built-in insecticides) may harm the larvae of Monarch Butterflies on nearby plants. How many insects does it take to accept the risk is too high?

For more:
"The Case for a GM-Free Sustainable World, 2003" Independent Science Panel (ISP).

Available for free download from Food First

Glossary of GM terms http://europa.eu.int/comm/agriculture/publi/gmo/fullrep/gloss.htm

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