Effect of ballast water on marine ecosystem

Abstract

The coasts of the world are interconnected by extensive use of shipping routes. Ballast water is carried in ships to provide stability and trim. Discharge of ballast water may impact on the marine environment in various ways, and it is the major vector for the transfer of nonindigenous aquatic species from one region to another. These organisms often include non-native, alien, nuisance, exotic, and invasive species which can cause extensive ecological and economic damage to marine ecosystems. Introduction of invasive species is one of the major factors adversely affecting biological diversity, and they threaten many native species in the host environment till the extinction. To prevent and minimize the risk of introduction of invasive species, ballast water treatment technologies and legislations were developed by the International Maritime Organization (IMO). Coasts of Turkey are one of the most vulnerable areas for the intensive maritime traffic. Currently, there is 23 million tons of ballast water discharged to national coastal waters. Turkey ratified Ballast Water Management Convention (BWMC) in October 2014, and BWMC will enter into force 12 months after it has been ratified by 30 states representing 35% of the world’s merchant shipping tonnage.