A summary of findings from the first 25 Ballast Water Treatment Systems evaluated by GESAMP

As part of the preparations for entry into force of the Ballast Water Convention (2004), the International Maritime Organization has initiated a process to evaluate the safety and efficacy of potential technologies for disinfecting ballast water on board ships. Ballast Water Management Systems intended to remove potentially ‘harmful aquatic organisms’ are subjected to a review process, one aspect of which is aimed at ensuring safety by assessing the risks of the systemto the environment, human health (including the ships crew) as well as the safety of the ship. With 25 systems in the various stages of the evaluation process and some already approved, this paper takes a first look at the types of systems under development, especially their environmental characteristics and look for any emerging trends. Quite awide range of different technologies are being developed based on chemical, physicochemical and physical mechanisms. Of these, chlorination by electrolysis in-situ is the most common and indications are that such systems may become even more common.