If in-water cleaning methods are used for removing biofouling in ports and marinas, it is possible that viable biological material is released back to the water, causing elevated risk of introduction of new species. It is especially problematic in ports which are located close to sensitive areas (like nature reserves) or locations where the settlement of newly arrived species would be easy (like industrial seawater discharge sites that are warmer than the surrounding sea areas). Ports also offer favorable settlement surfaces for NIS on various types of man-made structures.

The information about the geographical location of ports and marinas, and their relative distance from potentially sensitive areas and easily invadable areas like the warm water discharge sites will be taken into account. The locations of these sensitive areas will be collated and visualized on a map.