Small recreational boats can travel long distances, and their relatively low speeds (compared to commercial ships) make them ideal vectors for fouling species. They can be responsible for both primary introductions and secondary spread of non-indigenous species. The number of leisure boats operating in the Baltic Sea Region is growing, and the risk of potential new introductions is also increasing.

The role of leisure boats and leisure boat trailers in the spreading of harmful aquatic organisms and pathogens in the Baltic Sea Region is largely unknown. It is essential to be aware of this risk and its magnitude in order to address the issue with the most cost-effective measures.

Based on the estimation of biofouling potential, recommendations will be produced for mitigating potential risks related to biofouling of leisure boats. These recommendations will help in optimizing the cleaning frequency and minimizing the risk of bioinvasions.