A decision support tool for ship biofouling management in the Baltic Sea

Biofouling of ships causes major environmental and economic consequences all over the world. In addition, biofouling management of ship hulls causes both social, environmental and economic risks that should all be considered reaching well-balanced decisions. In addition, each case is unique and thus optimal management strategy must be considered case-specifically. We produced a novel decision support tool using Bayesian networks to promote the comprehensive understanding about the complex biofouling management issue in the Baltic Sea and to identify potential management options and their consequences. The tool compares the biofouling management strategies in relation to NIS (non-indigenous species) introduction risk, eco-toxicological risk due to biocidal coating, carbon dioxide emissions resulting from fuel consumption and costs related to fuel consumption, in-water cleaning and coating. According to the results, the optimal biofouling management strategy would consist of a biocidal-free coating with regular in-water cleaning and with devices collecting the material. However, the best biocidal-free coating type and the optimal in-water cleaning interval varies and depends e.g. on the operational profile of the ship. The decision support tool can increase the multi-perspective understanding about the issue and support the implementation of the optimal biofouling management strategies in the Baltic Sea.