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Genetically modified (GM) crops may contribute to increased productivity in sustainable agriculture, according to a groundbreaking study published in the June 8 issue of the journal Science. The study analyzes, for the first time, environmental impact data from field experiments all over the world, involving corn and cotton plants with a Bt gene inserted for its insecticidal properties. The research was conducted by scientists at the National Center for Ecological Analysis and Synthesis (NCEAS) at the University of California, Santa Barbara, The Nature Conservancy, and Santa Clara University. The study is accompanied by a searchable global database for agricultural and environmental scientists studying the effects of genetically engineered crops.

Biotechnology and genetic engineering are controversial because of concerns about risks to human health and biodiversity, but few analyses exist that reveal the actual effects genetically modified plants have on other non-modified species. In an analysis of 42 field experiments, scientists found that this particular modification, which causes the plant to produce an insecticide internally, can have an environmental benefit because large-scale insecticide spraying can be avoided. Organisms such as ladybird beetles, earthworms, and bees in locales with “Bt crops” fared better in field trials than those within locales treated with chemical insecticides.

“This is a groundbreaking study and the first of its kind to evaluate the current science surrounding genetically modified crops. The results are significant for how we think about technology and the future of sustainable agriculture,” said Peter Kareiva, chief scientist of The Nature Conservancy.

According to lead author, Michele Marvier, of Santa Clara University, “We can now answer the question: Do Bt crops have effects on beneficial insects and worms" The answer is that it depends to a large degree upon the type of comparison one makes. When Bt crops are compared to crops sprayed with insecticides, the Bt crops come out looking quite good. But when Bt crops are compared to crops without insecticides, there are reductions of certain animal groups that warrant further investigation.” What is clear is that the advantages or disadvantages of GM crops depend on the specific goals and vision for agroecosystems.

As NCEAS Director, Jim Reichman explains, “This important study by an interdisciplinary research team reveals how an in-depth analysis of large quantities of existing data from many individual experiments can provide a greater understanding of a complex issue. The project is enhanced by the creation of a public database, Nontarget Effects of Bt Crops, developed by NCEAS ecoinformatics expert, Jim Regetz, that will allow other scientists to conduct congruent analyses.”

The National Center for Ecological Analysis and Synthesis (NCEAS) was created in 1995 with funding from the National Science Foundation, the State of California, and the University of California Santa Barbara. The Center facilitates collaborative research and the synthesis of existing data on ecology and the environment. NCEAS scientists develop new techniques in informatics, and apply general knowledge of ecological systems to specific issues such as the loss of biotic diversity, global change, habitat decline and fragmentation, and over-exploitation of natural resources. NCEAS is associated with the Marine Science Institute and is located in downtown Santa Barbara.
 

Study by Santa Clara University professor finds some genetically engineered crops could play a role in sustainable agriculture

Possible benefits include reduced use of chemicals in crops modified with insecticidal gene

Arlington, Virginia
June 7, 2007

A new study published today in SCIENCE magazine evaluates current data on the harms and possible benefits of genetically modified (GM) crops, and finds that genetically modified crops may, in some cases, contribute to more sustainable agricultural practices. The study, titled “A Meta-Analysis of Effects of Bt Cotton and Maize on Nontarget Invertebrates,” for the first time analyzes environmental impact data from field experiments all over the world involving corn and cotton with a Bt gene inserted for its insecticidal properties. The research was conducted by scientists at Santa Clara University, the National Center for Ecological Analysis and Synthesis (NCEAS) at the University of California Santa Barbara, and The Nature Conservancy, and is accompanied by a searchable global database for agricultural and environmental scientists studying the effects of genetically engineered crops.

Biotechnology and genetic engineering are controversial because of concerns about risks to human health and biodiversity, but the studies performed to date to assess the actual effects that genetically modified plants will have on other species have generally been poorly replicated, with only a few field plots in each experimental treatment. After analyzing 42 field experiments, scientists found that this particular engineered modification, which causes the plant to produce insecticide internally, can have an environmental benefit because the entire crop no longer has to be sprayed with chemicals. Specifically, the research team found that organisms such as ladybird beetles, earthworms, and bees within these “Bt crops” fared better in field trials compared to conventional agriculture, which uses large-scale insecticide spraying.

“This is a groundbreaking study and the first of its kind to evaluate the current science surrounding genetically modified crops. The results are significant for how we think about technology and the future of sustainable agriculture,” said Peter Kareiva, chief scientist of The Nature Conservancy and co-author of the report. “The debate surrounding genetically modified crops is challenging and divided, but the more information we have, the better - so that we can work together to inform decisions that ensure human health, economic security and long-term sustainability.”

While this study highlights that in some cases biotechnology might actually produce environmental benefits (compared to traditional farming practices), the results are different when comparing GM crops to fields not treated with any insecticides. In such cases, the researchers found instances where the abundance of “non-target” species was greater in the no-spray field plots compared to in the genetically engineered field plots.

“We carried out this research because we found that most of the studies submitted by industry to the US regulatory bodies (US EPA & USDA) had been poorly replicated and therefore could have ‘missed’ important side effects of these crops,” said Michelle Marvier, and co-author of the report. “We can now answer the question: Do Bt crops have effects on beneficial insects and worms? The answer is that it depends to a large degree upon the type of comparison one makes. When Bt crops are compared to crops sprayed with insecticides, the Bt crops come out looking quite good. But when Bt crops are compared to crops without insecticides, there are reductions of certain animal groups that warrant further investigation.”

Kareiva added, “The lesson is clear—it is misguided to make blanket assumptions about new agricultural technologies as either ‘good’ or ‘bad.’ The answer is that the effects of GM crops depend on your goals and vision for agroecosystems.”

The researchers and ecoinformatics experts at NCEAS produced a global database, Nontarget Effects of Bt Crops. Co-author Jim Regetz of NCEAS describes the database as “bringing together methodological details and results from a large collection of experimental and observational research. NCEAS makes this and other data sets available to the public with the intention that future analyses by the broader scientific community will yield important new insights.”

Santa Clara University, a comprehensive Jesuit, Catholic university located 40 miles south of San Francisco in California’s Silicon Valley, offers its 8,377 students rigorous undergraduate curricula in arts and sciences, business, and engineering, plus master’s and law degrees and engineering Ph.D.s. Distinguished nationally by one of the highest graduation rates among all U.S. master’s universities, California’s oldest operating higher-education institution demonstrates faith-inspired values of ethics and social justice.

US study: Bt crops more ecological than conventional cultivation

Source: GMO Compass

Bt plants have fewer damaging effects on biodiversity than does the application of insecticides in conventional farming. The tallies are even better when insecticides are fully avoided. This is the conclusion of a meta-study compiled by a group of ecologists of Santa Clara University in California and published in the current issue of Science magazine.

The ecologists evaluated, under consistent criteria, a total of 42 individual studies of Bt plants and their effects on non-target organisms. This was aimed at allowing comparison between individual results and to determine general tendencies. A broad database thereby has been made available that allows "empirically sound conclusions to be drawn."

All studies incorporated in the meta-study are publicly available in a specially established database. Studies of Bt cotton (Cry1Ac) and Bt maize were included, as well as of the Bt variant Cry1Ab that is effective against the European corn borer and of the Cry3Bb toxin that is effective against the corn root borer.

The authors of the meta-study draw the conclusion that the Bt toxins of transgenic plants affect non-target organisms. However, such effects are significantly lower than those caused by the application of insecticides. All variants of Bt toxins function in a targeted manner and are more specific than chemical insecticides or Pyrethroids, a plant-derived agent used in the control of the corn root borer. When, however, no insecticide is used on the control fields, the incidence of non-target organisms in these fields is slightly higher than on Bt fields.

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