To minimize the risk that non-native species are transported with ballast water the International Maritime Organization has developed the Ballast Water Management Convention, a convention that stipulate requirements for ships that are releasing their ballast water. In practice this means that ships have to install approved ballast water treatment systems onboard.
In the convention the possibility of exemptions is included for some shipping routes when it can be proven that ballast water transports will not pose a threat to the environment.
To be able to grant such exemptions in European waters a port sampling protocol as described in the HELCOM/OSPAR protocol by the HELCOM and OSPAR task group on Ballast water Exemptions.
GiMaRIS has performed the inventories of the port of Rotterdam, NL (2014), the port of Hull, UK (2015), the port of Vlissingen, NL (2016) and the port of Antwerpen, BE (2017) following the HELCOM/OSPAR protocol. The request for the Rotterdam-Hull exemption is currently pending.