Marine bioinvasion: concern for ecology and shipping

Abstract

Marine bioinvasion - introduction of marine organisms alien to local ecosystem through ship hulls and ballast water - has serious consequences to native biota, fishery and general coastal ecosystem. Over 80% of the world cargo is mobilized transoceanically and over 12 billion tones of ballast water is filled at one part of the ocean and discharged at the other. These ballast waters offer conducive situation for bacteria, viruses, algae, dinoflagellates and a variety of macro-faunal larval/cyst stages to translocate to alien regions, usually along the coasts of the continents. As an example, there are over 18 species of animals and plants documented along the Indian coasts as those that might have got invaded and established. They can cause deleterious effects to local flora and fauna through their toxigenic, proliferative and over-competitive characteristics. This article points out the threats arising out of marine bioinvasion and various technological developments needed to deal with this unavoidable scourge in global shipping transport.