I previously made a post about not feeding wildlife. 
Genetically Modified Organisms and Wildlife:
Do Not Allow Hundreds of Possibilities for Progress to be Lost due to a Few Unlikely Events
Abstract
Genetically modified organisms are species that have foreign DNA inserted into them to make them express more favorable traits. People have reservations about GMOs because they are well aware of the possibility of horizontal gene transfer, cross pollination and accidental harm to non-target species. All of which could negatively impact wildlife. Many studies have been done to test whether each of the above concerns is reasonable. Studies revealed that most GMOs do not have apparent risks to wildlife, but there are a few specialized cases where negative impacts were eminent. Additionally, a small number of studies have actually proven GMOs to be beneficial to wildlife, therefore we need to follow in these researchers footsteps and continue to advance GMOs in a manner that is beneficial to the environment.
Highlights:
• Genetically modified organisms can transfer DNA through horizontal gene transfer at low frequencies
• Regulations on GMOs are becoming stricter because of the potential risks to wildlife.
• GMOs can be beneficial to wildlife.
• Cross pollination can occur among genetically modified organisms and wild relatives
• Non target species may or may not be affected by GMOs and testing must be done for determination
Key Words:
Genetically modified organisms, GMOs, Wildlife, Environmental Impacts, Gene Transfer.
1. Introduction
Genetically modified organisms, GMOs, are species that have foreign DNA inserted into them to enhance favorable traits (Fitzpatrick, 2013). Various genes can be transferred and modified amongst different organisms to obtain genetic expression when and how we so desire. This is possible because all species have a similar code and share a high percentage of the same genes. The only universal mechanism for conveying instructions for the production and existence of organisms is nucleic acid (Beringer, 2000). To create GMOs, restriction enzymes are used to “cut” desired sections of DNA from one organism and ligase assists in “gluing” that particular genetic information into another organism (Fitzpatrick, 2013). With the new DNA, the second organism produces new proteins that redirect or enhance some function of the organism.
GMOs are continuously being used in more and more industries. Currently, biomedical, agricultural, biofuels and biotechnical industries are all taking advantage of the possibilities GMOs have to offer (Strauss et al. 2010; Myhr and Traavik, 1999). The majority of GMOs, however, are being used in agriculture, namely in the modification of various commercialized crops. In fact, between 1997 and 2007, more than 800 million ha of genetically modified crops have been grown (Strauss et al., 2010). However, these advancements do not come without some risk.
Many studies have been done that reveal potential problems that can occur from GMOs but similarly many studies provide lack of evidence for negative effects. GMOs can greatly influence the environment in which they are released and each one interacts and affects each environment differently. Because of uncertainty and the desire to protect wildlife, restrictions are becoming ever increasingly strict, even though many GMOs likely have no effects or are actually beneficial to wildlife (Fitzpatrick, 2013; Strauss et al., 2010; O’Callaghan et al., 2005). This paper is intended to give insight into the restrictions under which GMOs have been placed due to wildlife protection and the potential risks and benefits GMOs have on wildlife based on various case studies. Although more information is necessary to prevent catastrophes, we should advance GMOs in a manner that benefits wildlife.
2. Regulations
Regulations on GMOs have become extremely important because the need to protect both human and wildlife health is of huge public concern. Countries all over the world have their own agencies and standards for GMO regulations (O’Callaghan et al., 2005). I will focus on the agencies, testing methods, and restrictions in the United States. Before a GMO can be commercialized, it must undergo rigorous testing that is completed in four major steps; 1) conducting laboratory and greenhouse studies, 2) limited field trials in a small number of varieties and environments, 3) various forms of the genes are tested to obtain the most optimal version for the intended purpose, 4) The most favored gene is inserted into commercial varieties and tested in many environments (Strauss et al., 2010).
There are three agencies that approve and ensure safe GMO testing. The FDA (Food and Drug Administration) oversees any GMO that could affect food (Strauss et al., 2010). The EPA (Environmental Protection Agency) regulates all GMOs that protect against any type of pests. Lastly, USDA APHIS (United States Department of Agriculture Animal and Plant Health Inspection Service) is responsible for all genetically engineered crop field trials. Their authorities and restrictions have greatly increased due to trace amounts of GM crops contaminating nearby environments (Strauss et al., 2010). Newer regulations require permits for any and all field trials. Obtaining permits currently takes up to five hundred days, when prior to regulation changes permits could be obtained in as short as a week (Strauss et al., 2010). This time constraint is a huge barrier for developers, who are already limited by time and funding. As restrictions become more burdensome, developers will be discouraged and possibly unable to ever test potentially beneficial GMOs.
Some of the hesitation people have with GMO advancements stem from the fear that it could harm themselves and the environment. If indeed, the environment is one of the public’s main priorities, then extreme regulations on GMO testing is an excellent choice because it will prevent worst case scenarios that have a very low probability of occurring (Berlinger, 2000). However, most people would rather have a house to live in and food on their plate than a beautiful location to recreate in; therefore we should not allow wildlife to impact GMO regulations to a degree that inhibits GMO advancements.
3. Potential Risks to Wildlife: Is There Reason for Concern?
There are a vast number of possible interactions that could potentially occur from the use of GMOs. Some GM crops, such as Serine Protease Inhibitors have shown to have negative effects on unintended organisms, such as honey bees, while the majority of GM crops and other GMOs, such as certain types of GM cotton and maize, have shown no negative effects on numerous insect and herbivorous species, such as honey bees and whitetail deer (O’Callaghan et al., 2005; Fitzpatrick, 2013) These studies are limited, however, and need additional experimentation to confirm or deny the harm GMOs can cause. Potential risks along with their associated case studies are described in detail below.
3.1 Horizontal Gene Transfer
Horizontal gene transfer (HGT) is the transfer of genetic information between two organisms without any sexual contact (Myhr and Traavik 1999). This can occur between related species and it can occur between unrelated species, such as plants and bacteria (Conner et al., 2003). Horizontal gene transfer is of concern for a few reasons. First, genetically modified crops (GM crops) are capable of passing genetic material on to bacteria in the soil (Conner et al. 2003). This genetic material can potentially alter the function of these bacteria and make them more likely to infect and cause harm to other species. Soil bacteria that receive modified genes may also function in a manner that alters ecological processes. The nitrogen and carbon cycles rely on bacteria for proper decomposition rates and genetically modified bacteria through HGT may negatively impact these cycles through immobilization and slowed decomposition of organic matter (Conner et al., 2003).
Lastly, all animals rely on bacteria in their guts to help them digest food. There is a potential risk for herbivores that consume genetically modified plants because the plants may transfer genetic material to the gut bacteria and redirect or inhibit their normal functions (Myhr and Traavik, 1999). Antibiotic resistance genes could alter harmless gut bacteria into dangerous pathogens (Conner et al., 3003). Although there is plenty of evidence that supports the possibility of HGT, several studies have failed to demonstrate any issues arising with GMOs and horizontal gene transfer (Conner et al., 2003). DNA may frequently enter new cells through HGT, but rarely is it actually integrated into the genome and passed on to progeny (Berlinger, 2000). Therefore, GMOs are highly unlikely to pose a threat to wildlife through horizontal gene transfer.
3.2 Cross Pollination
Cross pollination occurs when a GMO and a wild relative cross breed and create hybrids. If these hybrids are capable of reproducing offspring, new genetic material can invade surrounding ecosystems. If the genetic material has a competitive advantage, natural relatives may be outcompeted and species may be lost (Conner et al., 2003). Herbicide and pesticide resistant genes can also be transferred to weedy relatives, which can easily take over areas and reduce biodiversity (Myhr and Traavik, 1999). Resistant weeds also pose an issue for farmers who will need to use more herbicides and pesticides to protect crops. Excess herbicides and pesticides can end up contaminating water supply and neighboring wildlife.
A study in France revealed that GM oilseed rape can cross with wild radish and occasionally those hybrids are capable of producing offspring (Myhr and Traavik, 1999). Additional field trials on GM oilseed rape in Scotland and Denmark discovered that it can cross with wild varieties of Brassica (Myhr and Traavik, 1999). Although cross pollination is clearly possible, Crawley et al. spent 3 years examining the invasiveness of oilseed rape into natural habitats. They proved it is not invasive and GM oilseed rape was not any more likely to exist in disturbed areas than its natural counterpart (Conner et al., 2003).
The likelihood of cross pollination with crops is fairly low and having those that do cross pollinate become invasive, even lower. It is much more likely that cross pollination will be problematic in industries beyond agriculture. Genetically modified algae, which could be used to produce biofuels, have the ability to increase populations at a rapid rate (Snow and Smith, 2012). If cross pollination occurs, the genes could be spread throughout an ecosystem at a pace that might seem unstoppable (Snow and Smith, 2012). Less competitive species would be lost and biodiversity reduced. Studies on this are currently being conducted and information is extremely limited to the public (Snow and Smith, 2012).
At the other end of the spectrum, genetically modified trees, which are used in the pulp and paper industry, are also more likely to be hazardous through cross pollination than crops. Trees have excellent dispersal methods which enable their genetic material to be spread long distances (Petermann, 2007). These distances could allow hybrids to establish and contaminate native forests (Petermann, 2007). In 2004, researchers at Duke University created pollen models that suggested that pollen from Southeast US trees could travel over 1 000 miles away into eastern Canada (Petermann, 2007). No studies have exhibited any evidence of harm to the environment from GM trees to date, but the extreme distances tree pollen can travel makes field trials complicated and risky.
3.3 Non Target Harm
Genetically modified crops can potentially affect non target species that feed on them. One of the major concerns is negative impacts on insects. Many insects are considered keystone species and the loss or alteration of them is likely to impact entire ecosystems. One of the most commonly studied insects is bees. Researchers have had mixed reports on the impacts insect resistant GM crops have on bumble bees and honey bees. For cotton and maize with Bacillus thuringiensis (Bt) genes inserted into them, multiple studies concluded that the bees did not have any side effects from consuming these modified crops (O’Callaghan et al., 2005). In fact, several different insect resistant genes were tested and the only one that had negative impacts were serine PIs which caused changes in the digestive protease and reduced survival rates when consumed in large concentrations (O’Callaghan et al., 2005). Many large herbivores that consume GM crops are also unaffected. Farmland deer and turkeys consume a significant quantity of GM crops and neither has shown any side effects (Fitzpatrick, 2013).
Another potential problem with GM crops is the alteration or loss of prey for predators. Many species feed on insects that consume GM crops (O’Callaghan et al., 2005). A reduction in insect numbers will have a domino effect and reduce population sizes of species that consume them, and so on. Prey that consumes GM crops may potentially become unpalatable, nutrient poor, or indigestible for predators (O’Callaghan et al., 2005). Field studies report mixed results on the effects of arthropod predator abundance, which consumed insects that fed on Bt GM cotton (O’Callaghan et al., 2005). One particular study showed that Bt toxins did not harm Green Lacewing (Chrysopa carnea), however, the lower quality Bt maize that was fed to the prey may have had an effect (O’Callaghan 2005). When an option was available, lacewings chose to feed on non Bt-fed caterpillars over Bt-fed larvae (O’Callaghan, 2005). Out of nine predator species of GM fed prey that were studied, only one, Coleomegilla maculata larvae, was found to have a significantly decreased population density (O’Callaghan, 2005). However, the same type of negative effects will occur from spraying insecticides across fields as insect resistant crops will (Berlinger, 2000). If insect resistant genes are more cost effect and do not require expelling fuel into the atmosphere in the process of spraying crops, it seems to be, even with some potential risks, the better option.
4. Benefits to Wildlife
There is potential to assist and benefit wildlife using GMOs. Studies that provide evidence for benefits are limited but significant. These few studies may lead others to realize the full potential GMOs have, in not only benefitting our economy, but our environment as well. GMOs have the potential to be used as biofuels commercially, which would cut down toxic emissions and help preserve our atmosphere (Snow and Smith 2012). Genetically modified trees also could have some huge benefits to wildlife. Modifying trees in a manner that reduces lignin levels provides no competitive advantage, so gene flow into surrounding areas would quickly dissipate. Reduced lignin, however, means that the trees are easier to process, resulting in less pollution through by-products and mitigation of climate change (Petermann 2007).
Using GMOs to bring back species that were historically wiped out is another potential application. Currently a research team is modifying the genome of the American Chestnut Tree, which was very common in the Eastern US before the 1900s (Powell 2014). The goal is to revive a species, which not only provides economic value, but was once a key stone species in deciduous forests (Powell, 2014). The loss of the American chestnut tree resulted in wildlife population declines and loss of biodiversity (Powell, 2014). Returning forests back to a state full of chestnut trees has a high likelihood of increasing biodiversity and stabilizing populations of numerous dependent species.
Wildlife can also benefit from studies similar to that done in Sweden, where growth rates and brain morphology were examined in Coho Salmon using wild and GM fish (Kotrschal et al., 2012). The GM fish only varied from the wild fish in that they were inserted with a fast-growing gene (Kotrshcal et al., 2012). The study revealed that both environment and genetics influence brain structure and size (Kotrschal et al., 2012). GMOs can be used to study internal functions of different organisms and enable ecologists to get a better understanding of different species. Increased knowledge would then lead to better management practices.
Literature Cited
Beringer, J., 2000. Releasing genetically modified organisms: will any harm outweigh any advantage? J. Appl. Ecol. 37, 207-214.
Conner, A., Glare, T., Nap, J., 2003. The release of genetically modified crops into the environment; part II. Overview of ecological risk assessment. Plant J. 33, 19-46.
Fitzpatrick, B., 2013. Frankenbucks; are genetically modified crops a threat to wildlife populations, and to the health of those of us who eat them. Outdoor Life. 220, 52.
Kotrschal, A., Sundstrom, L., Brelin, D., Devlin, R., Kolm, N., 2012. Inside the heads of David and Goliath: environmental effects on brain morphology among wild and growth- enhanced coho salmon Oncorhynchus kisutch. J Fish Biol. 81, 987-1002.
Myhr, A., Traavik, T., 1999. The Precautionary Principle Applied to Deliberate Release of Genetically Modified Organisms (GMOs). Micro. Ecol. Health D. 11, 65-74.
O’Callaghan, M., Glare, T., Burgess, E., Malone, L., 2005. Effects of Plants Genetically Modified for Insect Resistance on Nontarget Organisms. Ann. Rev. Entomol. 50, 271-292.
Petermann, A., 2007. Frankenforests; native forests, communities at risk from the genetically modified tree industry. Earth Isl. J 29-34.
Powell, W., 2014. The American Chestnut’s Genetic Rebirth. Sci. Am. 310, 68-73.
Snow, A., Smith, V., 2012. Genetically Engineered Algae for Biofuels: A key role for ecologists. Bioscience 62, 765-768.
Strauss, S., Kershen, D., Bouton, J., Redick, T., Tan, H., Sedjo, R., 2010. Far-Reaching Deleterious Impacts of Regulation on Research and Environmental Studies of Recombinant DNA-modified Perennial Biofuel Crops in the United States. Bioscience 60, 729-741.
