There are long standing concerns worldwide regarding the effects of the introduction of alien species and genetically improved lines into national waters. The expansion of global trade and aquaculture has augmented these concerns. National and international agencies have reviewed and continue reviewing policies and procedures related to proposed introductions of alien species and transfers within and between countries It is important to integrate development objectives with conservation objectives. Appropriate authorities of the importing countries should examine the proposal and the justification for introduction in order to decide whether to go ahead with the proposed introduction or not. Abiding by an appropriate Code of Practice will help promote good decisions, avoid costly mistakes, and help improve the standard of living of the communities concerned.