Effects of genetically modified crop plants on the aquatic environment?


Foto: Thomas Bøhn

Photo: Thomas Bøhn

A new publication from GenØk reviews how genetically modified (GM) crop plants may impact streams and other aquatic ecosystems. Aquatic ecosystems have generally been neglected as a relevant context for research and risk assessment, although crop residues, including a number of Bt toxins and herbicides, will end up in nearby aquatic communities. Negative effects are documented on aquatic insects and waterfleas. As the trend for using of Bt crops with multiple transgenes – including those used in conjunction with herbicides such as glyphosate – continues, we consider the possible implications for aquatic organisms and make suggestions for further research.

Abstract: The term Bt crops collectively refers to crops that have been genetically modified to include a gene (or genes) sourced from Bacillus thuringiensis (Bt) bacteria. These genes confer the ability to produce proteins toxic to certain insect pests. The interaction between Bt crops and adjacent aquatic ecosystems has received limited attention in research and risk assessment, despite the fact that some Bt crops have been in commercial use for 20 yr. Reports of effects on aquatic organisms such as Daphnia magna, Elliptio complanata, and Chironomus dilutus suggest that some aquatic species may be negatively affected, whereas other reports suggest that the decreased use of insecticides precipitated by Bt crops may benefit aquatic communities. The present study reviews the literature regarding entry routes and exposure pathways by which aquatic organisms may be exposed to Bt crop material, as well as feeding trials and field surveys that have investigated the effects of Bt-expressing plant material on such organisms. The present review also discusses how Bt crop development has moved past single-gene events, toward multigene stacked varieties that often contain herbicide resistance genes in addition to multiple Bt genes, and how their use (in conjunction with co-technology such as glyphosate/Roundup) may impact and interact with aquatic ecosystems. Lastly, suggestions for further research in this field are provided.

Venter, H.J. and Bøhn, T. 2016. Interactions between Bt crops and aquatic ecosystems: A review. Environmental Toxicology and Chemistry. DOI: 10.1002/etc.3583


For further information, please contact:

Thomas Bøhn, Senior Scientist/Program Coordinator, GenØk


+47 97 00 99 16