CHAPTER 6 PREVENTING GENETIC POLLUTION AND THE ESTABLISHMENT OF FERAL POPULATIONS: A MOLECULAR SOLUTION PETER M. GREWE, PH.D. 1 , JAWAHAR G. PATIL, PH.D. 1 , DANIEL J. MCGOLDRICK, PH.D. 2 , PETER C. ROTHLISBERG, PH.D. 3 , STEVEN WHYARD, PH.D. 4 , LYN A. HINDS, PH.D. 5 , CHRIS M. HARDY, PH.D. 6 , SOMA VIGNARAJAN 7 , AND RON E. THRESHER, PH.D. 8 1 CSIRO Marine and Atmospheric Research, GPO Box 1538, Hobart, Tasmania 7000, Australia (E-mail: peter.grewe@csiro.au) 2 University of Colorado Health Science Center at Fitzsimons, 12801 East Seventeenth Avenue, Aurora, Colorado 80010, USA 3 CSIRO Division of Marine and Atmospheric Research, Cleveland, Queensland 7000, Australia 4 Department of Zoology, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 5 Senior Principal Research Scientist, CSIRO Entomology, GPO Box 1700, Canberra, ACT 2601, Australia 6 Principal Research Scientist, CSIRO Entomology, GPO Box 1700, Canberra, ACT 2601, Australia 7 CSIRO Livestock Industries, New England Highway, Armidale, New South Wales 2350, Australia 8 CSIRO Marine and Atmospheric Research, Hobart, Tasmania 7000, Australia Abstract: Aquaculture animals that escape from farms have the potential to create major environmental problems. These include establishment of potentially destructive feral populations (e.g., Pacific oysters [Crassostrea gigas] in Australia, Atlantic salm- on [Salmo salar] in British Columbia) and genetic contamination of wild stocks. The latter includes introgression of foreign genes into natural populations from both hatchery-reared fish and genetically modified fish and invertebrates. Concern about these environmental and genetic effects has already led to restrictions on aquaculture industry development and is likely to grow as demand for genetically improved stocks escalates to fulfill production objectives. To circumvent these problems, we have developed a genetic construct that, when properly integrated into production-line fish or invertebrates, should render individuals functionally sterile outside of hatchery conditions. In the hatchery, however, provision of a simple repressor compound at a particular life-history stage allows the animals to be bred and reared as normal. We Theresa M. Bert (ed.), Ecological and Genetic Implications of Aquaculture Activities, 103–114. ß 2007 Springer. 103