Genetically Modified Organisms as Invasive Species

July 6, 2000

Michael Johnsen

How can genetically modified organisms (GMOs) be dangerous? Most of the context of GMOs exist in new hybrid crops planted by farmers which have been drawing fire as dangerous from environmental groups such as Greenpeace. Currently, many stocks of soybean crops in the United States and other countries have been genetically modified; meaning that genes have been inserted or replaced to give the new plant characteristics not normally found in nature.

In the role of agriculture, these new crops may produce a natural insecticide, or, in the case of Monsanto's soybean version, the plants are immune to Roundup, an herbicide produced by Monsanto. The benefit here is that Roundup can be sprayed on the crops to kill weeds, yet not harm the soybean plants. Another popular example is corn which produces Bt, a bacteria which causes a stomach disease in worms and bugs which prey on corn. Unfortunately, Bt, which is commonly used in organic farming, can harm beneficial species as well. Organic farmers use Bt at specific times, applied in limited amounts, to control harmful insects while preventing harm to non-targeted species. The genetically modified corn which produces Bt cannot distinguish between harmful and non-targeted species, leading to studies that the Bt may drift to milkweed and subsequently harm monarch butterflies.

The problems with GMOs is not necessarily the effects on people who eat a GMO product. More importantly is the problem of releasing new organisms into an ecosystem which has no checks or balances for the new species. This can be observed through the introduction of foreign species into the U.S. For example, kudzu, the notorious vine that can grow inches per day and has covered millions of square acres in the south-eastern U.S. has no natural predators in the States to stop it. Insect species, such as the gypsy moth, has caused millions of dollars of damage to trees since there are no predators that can keep the ravenous caterpillars at bay.

State and federal agricultural departments keep tight standards to try to prevent the invasion of these species. But no attention has been given to the effects these new GMOs may have on the environment. To illustrate an example of a plant that may have mutated into a monster, the Associated Press has reported on an algae, Caulerpa taxifolia, that has destroyed ruined more than 10,000 acres of Mediterranean Sea habitat near France, Spain, Monaco and Italy after patches found in the 1980s were not immediately destroyed. The algae has recently been discovered in Agua Hedionda near San Diego, the first time it has been confirmed on the west coast of the United States.

The effects of the algae are severe; Caulerpa has proven toxic to most sea life, forcing fish to go elsewhere and harming fisheries. Mediterranean scuba diving sites are being smothered by the plant, as are Riviera pleasure ports. The bright green, feather-like algae was commonly sold for use in aquariums until it was banned last year by federal law.

"This algae eliminates kelp beds and poses an extreme danger to flora and fauna in the area," said Bob Hoffmann, Southern California environmental coordinator for the National Marine Fisheries Service. "Effects on commercial and recreation fishing in the coastal areas would be severe [in the event of an outbreak]," Hoffmann said. "This is a very fast-growing species."

The plant was introduced to an aquarium in Stuttgart, Germany, in the 1980s and then to aquariums in Europe, Japan and South Africa. Hoffmann believes the algae likely ended up in Agua Hedionda after someone emptied the contents of their aquarium into a storm drain or the lagoon.

At first it appears to be another case of a non-native invasive species native to tropical waters, where it grows in small, isolated patches. But researchers think that it genetically mutated, perhaps because of exposure to the ultraviolet light used in aquariums. In the same way, purposely genetically modified organisms, produced with good intent, could run amok and cause havoc to ecosystems. By planting GMO crops, non-native species are being purposely released into the environment with little or no research into the potential affects these new life