Abstract
Deliberate release of genetically modified organisms (GMOs) may contribute to sustainable development, world food supplies and economic prosperity. On the other hand, environmental release may initiate serious, irreversible ecological damage. In this article we discuss the scientific basis for regulation of GMO use, and to which extent present risk assessment procedures provide means to predict and reduce potential ecological hazards. Potential hazards related to gene transfer from GMOs to indigenous organisms and prospects of secondary ecological effects are given special attention. It is important to recognize that possible adverse ecological effects may have impact on other processes affecting human and animal welfare. A major conclusion is that the present state of scientific knowledge is inadequate for reliable ecological risk assessment. The basic information with regard to mechanisms governing the environmental interactions of GMOs is insufficient. The ecosystems are too complex, and our understanding of them too fragmentary. Furthermore, currently available methods to monitor short and long-term ecological consequences of GMO release are non-existent or unreliable. Finally, the socio-economic and biodiversity aspects of GMO usage are ambiguous, and often unpredictable, based on the present state of knowledge. Hence, applying the precautionary principle should be an important basis for initiation of risk-associated research as well as for elaboration of more satisfactory risk assessment methods and procedures.