Mohammad Reza KHEDMATI - Assis.Prof. of Marine Structural Eng. Faculty of Marine Technology, Amirkabir University of Technology, Tehran, Iran
Hesam MIRZAEI RAFSANJANI - BSc Student Faculty of Marine Technology Amirkabir University of Technology Tehran, Iran

Many non-indigenous species have been introduced into the marine environment through ships' ballast water. The environmental and economic impact of these unwanted aquatic organisms is substantial and growing. The International Maritime Organization (IMO) adopted voluntary standard calling for ships to implement procedure to minimize the introduction of unwanted aquatic organisms from ballast water in 1993, and in 1997 adopted the IMO guideline for management of ships' ballast water. The United Nations Convention on the Law of the Sea also requires signatory nations to "take all measures necessary to prevent, reduce and control the international or accidental introduction of species, alien or new, to any part of the marine environment, which may cause significant or harmful changes thereto."