``If New Zealand embraced it [genetic engineering] it would be a catastrophe for the health and environment of our country.''
Protest organiser Martin Sharp of Rotorua said genetic engineering should be contained to the laboratory.
``That's where it's doing some good,'' he said. ``If gene technology goes wrong we could end up with no life on the planet. That's the worst case scenario.''
Mr Sharp said it was telling the Government had spent $100,000 on the conference.
``We know that's John Key's agenda _ to push genetic engineering.''
Karen Hansen of Rotorua was so horrified to hear the conference was being held in her home town she printed off flyers to distribute around Rotorua.
``It [GE] really worries me because I see how evil it is,'' she said. ``Monsanto coming to my home town made me feel absolutely sick. They have been taking over the world one seed at a time.''
Green MP Steffan Browning has a members' bill in the ballot which would impose a 10-year moratorium on genetic engineering in New Zealand. He said New Zealand was effectively GE free, apart from two trials, and he believed keeping it that way was a big issue.
``Co-existence [of genetically engineered and conventional crops] can't work. Ultimately there will be cross-contamination.''
At 5pm the protesters were allowed into the events centre to attend a public lecture by Dr John Bedbrook, a New Zealander who is vice-president of DuPont Agricultural Biotechnology.
Dr Bedbrook spoke on global food security, and said with worldwide food demand projected to grow 70 to 80 per cent by 2050 one of the solutions would be ``embracing science-based techno logies''.
Conference organisers could not be reached for comment on the protest but Dr Paul Tan, chairman of conference host NZBIO, has said a wide range of technologies and approaches would be discussed at the conference, which this year had the theme ``Adapting to a Changing World''.
``Our goal is to facilitate informed debate that will help address some of the most pressing problems facing the world.''