Aquatic invasions cause environmental stress on freshwater, estuarine and marine ecosystems. Non-indigenous species can be introduced and distributed by natural spread or anthropogenic. Ships have been transporting species to new places since the first sailing ships were build thousands of years ago. The increase in shipping traffic, as well as the reduced transoceanic voyage times over the past century, has increased the number of non-native marine species introduced to new environments around the world.
Ballast water is considered as one of the most important shipping vectors. Since 1997 as parts of its efforts to minimise the transfer of harmful aquatic organisms and pathogens the industry has been implementing mid-ocean ballast water exchange standards. While this measure was believed to reduce the risk up to 95%, in 2004 the International Maritime Organisation adopted more stringent requirements to reduce further this risk. The International Convention for the Control and Management of Ship’s Ballast Water and Sediments Regulation D-2 which entered into force on 8 September 2017 help prevent the spread of potential harmful aquatic organisms and pathogens in ships’s ballast. The Convention requires ships to be fitted with a treatment technology that removes or render harmless aquatic organisms and pathogens from ballast water before it is being discharged in the new location.