One possible consequence: If the new organisms are better adapted than the original inhabitants, they may replace them in the long run. => EXTINCTION OF ANIMALS OR PLANTS !
Example One: The first german release experiment, involving petunias. In this experiment, the scientists wanted to detect "jumping genes" with a color change from pink to white. So they expected pink flowers with the one or other white blossom between. After some satisfying experiments in the greenhouse, the plants became released and almost every flower presented brilliant white blossoms! Heat and environment conditions had just switched off the new gene... This experiment has shown again that gene-manipulated organisms react rather unpredictable. But instead of stopping the releases until the complex relationships are explored, they demand MORE releases. Again, "Trial and Error"! The world as a playfield for the gene-tech scientists ...
Example Two: Often the genetech scientists claim that their creations won't survive in the nature. Judge these remarks with caution, especially if the organisms are designed for a release which means that they have to survive per definition. (By the way: A scientist named Curtis tried to develop micro-organisms which will self-destruct outside of the lab. He failed...). There are enough examples of the conventional plant development, which show that bastards between species are often MORE successful than the original species. For example, the american orchid Cypripedium Acaule is very difficult to grow, so it has been cross-breeded with a japanese species - with success! Perhaps, gene-manipulated plants will make bastards with wild species, too (for example manipulated rape seed with wild mustard seed, such bastards have already been observed) which has some completely new features. In the last years, many plants and animals from other continents have invaded new countries and partially replaced the original plants and animals. Australia is a particularly good example.