Implementation of the Ballast Water Management Convention: taking stock of progress and remaining challenges

Ships’ ballast water has been a global pathway for the introduction and spread of harmful aquatic organisms and pathogens. Following the first stages of the implementation of the International Convention for the Control and Management of Ships’ Ballast Water and Sediments (the Convention) to mitigate such introductions, a number of challenges were identified. Broadly, meeting the requirements of Regulation D-2 (the standard that limits the concentration of viable organisms in ballast water discharges) and balancing the operational demands of ballast water management with cargo activities have been difficult. A workshop was held in Halifax, Nova Scotia, Canada, in May 2024 at the 23rd International Conference on Aquatic Invasive Species (23rd ICAIS) to bring together global experts with relevant scientific, regulatory, and operational knowledge with the aims to, first, take stock of current challenges and second, identify solutions to improve future implementation of global ballast water management. Specific challenges were identified as: unexpectedly low rates of compliance (about 50%) with the discharge standard for organisms ≥ 50 μm in minimum dimension (the largest size class in Regulation D-2, typically zooplankton), inoperability of some equipment in water with high turbidity, and difficulty maintaining equipment. Areas for improvement include: strengthening equipment testing to improve compliance rates, comprehensive training for seafarers, streamlining administrative processes to support equipment modifications, developing standard procedures for equipment operation and maintenance, introducing enforcement activities based on document checks, and, implementing periodic and randomized testing to identify reasons for BWMS failure with a focus on organisms ≥ 50 μm. Workshop participants discussed how lessons learned from the implementation of the Convention to curtail ballast water-mitigated invasions could be applied in the ongoing development and future application of international biofouling regulations and guidance—another major global introduction pathway—with collection of data on the efficacy of in-water cleaning of ships using standardized, verified methods viewed as the most immediate and important step toward management development.