GM Algae: How safe are they?
Whilst the use of GM algae offer great potential to large scale production systems there are important safety concerns that must be addressed before being given the go-ahead. In nature, microalgae are important components of the trophic web to fisheries. Their ability to be readily transferred across and between continents provides important concerns over their effect on the natural environment and human health.
Quick Links:
This page gives a run down of some of the environmental and health risks associated with large scale growth of algal species and introduces some important concepts of how their risks may be avoided.
1. Survival and Persistence of GM algae in the Environment
The risk:
-
Escaped microalgae might persist outside of open ponds and enclosed bioreactors and become so abundant they create harmful algal blooms.
-
Introduced traits in GM algae such as enhanced growth rate, high photosynthetic efficiency and increased tolerance to harsh conditions might allow them to thrive and outcompete other species in natural environments.
-
The by-products from escaped GM algae may provide toxic effects to the environment and human health.
-
Unintended effects of GMs might produce new strains of harmful algae that could become persistent.
Risk mitigation:
-
GM algae must only be grown in enclosed photobioreactors which have a lower risk of contamination.
-
This does not, however, completely prevent the risk of unintended release.
-
-
Introduced GM traits should have minimal effects on the environment and reduce their ability to survive outside of their cultivation system
-
'Suicide genes' or other characteristics that would make survival outside of the photobioreactor impossible should be introduced to their genome
-
Eg. tolerance to certain conditions such as caffeine in the photobioreactor. In the absence of caffeine outside of the photobioreactor, algae would be unable to survive.
-
Problem: Environmental assessments are required to prevent GM algae evolving to silence these genes and overcome the traits designed to kill them.
-
2. Out of control evolution and transfer of engineered genes between other species
-
Algae have short life spans and high productivity rates. As a result they divide rapidly forming large populations and can adapt quickly to their new environment.
-
Some species can pass on their DNA between other microorganisms in a process known as horizontal gene transfer (HGT).
-
This is most common for the genes that give the organism a survival advantage in a particular environment.
-
-
These factors allow the algae to gain new traits that would increase their survival in the environment as well as passing on their genes which may enhance the survival of other organisms.
-
This may result in severe unknown knock on effects to ecosystems.
-
The risk:
Risk Mitigation:
-
Controlled field trials should be carried out over a longer period of time to identify potential and unknown risks.
-
Genetic markers can identify the presence of GM algae as well as the flow of a particular GM traits if released to the environment
Conclusion
Concerns over the potential risks of GM crop plants provide a good starting point to evaluate GM algae. However, algae are different to terrestrial plants by their dispersal and growth rates and may contain different engineered traits. At present there is a general consensus that too little consideration has been paid to the ecological concerns GM algae present. Huge funding has been fuelled into strain developments whilst little funding has focused on risk assessment of these organisms.
Risk assessments of these new algae species should therefore involve scientists with broad expertise and minimal conflicts of interest. Research into the possible risks of these new organisms should accompany current research into their development. Regulations must be passed before any new GM species is implemented. Potential benefits for carbon capture and sustainable fuel production must be weighed against these potential risks. Further research will improve these current regulations and assure their safety of use.