Characterization of environmental risk of genetically engineered (GE) organisms and their potential to control exotic invasive species

Abstract

Genetically engineered (GE) organisms could result in ecological harm in many ways in natural environments. Ecological harm can be assessed based on standard principles of risk assessment. Risk is the probability of harm as a result of a hazard, which in this case is a GE organism; its harm may not be known or knowable a priori, however, due to the large number of biotic interactions in nature in which it could be involved. We contend that for a GE organism to be a risk, it must be able to spread in nature. Thus, we do not have to determine all, or any, possible harms; we only need to be certain the organism will not spread if it escapes. Predicting the potential of a GE organism to spread is possible because the ultimate fate of a transgene will be determined by natural Aquatic Sciencesselection. Thus, environmental risk assessment can be accomplished by measuring six net fitness components that are common to all organisms, transgenic or wild type: juvenile and adult viability, fecundity, fertility, age at sexual maturity, and mating success. These components can be measured in secure settings. Previously, we focused on the environmental risk posed by GE organisms created to enhance agricultural productivity. Here we review the potential of using GE biotechnology for biological control of an existing undesirable exotic species. GE biological control might be employed to induce a 'Trojan gene effect' (Muir and Howard, 1999; 2002a,b) to eliminate such species, by introducing genes which cause male-biased sex ratios, inducible fatality, or selfish gene effects.

Building coral reef resilience through assisted evolution

“…A major concern is that artificially enhanced organisms might possess novel traits that give them a competitive advantage over the native population. From this perspective, artificially enhanced organisms are sometimes viewed as exotics (7), which can be invasive. For instance, of the 44 freshwater fish species that have been introduced into South Africa, 37% are considered invasive (8).…”

“…These concerns have been debated in relation to commercially important species (11) as well as plants and animals whose phenotypes have been altered by the insertion of foreign genetic material [i.e., genetically engineered (GE) organisms or genetically modified organisms (GMOs)] (7,12,13). Although the development of GMO corals might be contemplated in extremis at a future time, we advocate less drastic approaches (discussed in Assisted Evolution Approaches to Build Coral Reef Resilience) that use widely accepted techniques to accelerate naturally occurring evolutionary processes (e.g., random mutations, natural selection, acclimatization, and changes in microbial symbiont communities).…”

Managing Population Sex Ratios in Conservation Practice: How and Why?

“…many fish and amphibians) offer another approach, the so-called 'Trojan Y chromosomes' strategy ('Trojan' genetic elements were originally defined as elements that have the potential of driving local populations to extinction (Muir and Howard 2004)). The necessary prerequisites are that (i) the species in question displays male heterogamety (i.e.…”

Aquatic resources in arid lands: Issues and opportunities

“…Biotechnology may offer managers novel ways to control the spread of invasive species or to eradicate them entirely. The contribution of Muir and Howard (2004) addresses the increasingly important issue of invasive species in aquatic environments. They review the potential and environmental risk of using genetically engineered organisms for biological control of an existing invasive species.…”