Ballast Water Management Convention (BWMC)

The IMO Ballast Water Management Convention, adopted 2004 and in force 8 September 2017, requires ships to manage ballast water to stop the transfer of invasive aquatic species between ports. The interim D-1 exchange standard (mid-ocean exchange) is being phased out for the D-2 treatment standard, which caps viable organisms per cubic meter, met by type-approved treatment systems using filtration plus UV or chemical disinfection. Ships carry a ballast water record book and management plan.