Ballast water and invasive alien species

Non-indigenous species can be transported from one region to another through ballast water of large transport vessels, becoming invasive and competing with the local flora and fauna. Once populations of invasive species are established, they can spread easily, and severely damage the environment, human health or economic interests. To prevent the spread of harmful aquatic organisms through ballast waters, the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWMC) will enter into force in September 2017. Applied to its 172 member states, it will establish standards and procedures for the management and control of ballast water and sediments. Challenges to control invasive species include the high cost of ballast water treatment systems: ship owners are reluctant to implement such systems and the effects of invasive species are not necessarily felt evenly between economic sectors. Technical developments to address the problem of invasive species have intensified, focusing on prevention (ballast water treatment systems), early detection (metagenomics) and eradication of invasive alien species (citizens in science).

In addition to regulatory and technical responses, ocean literacy can play a key role in raising awareness among ship owners on the link between ballast water and invasive species, and of the effects that such alien species cause to the environment, economy and human health.

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