Risk Factors for Fouling Biomass: Evidence from Small Vessels in Australia

Invasive marine non-indigenous species are a major threat to marine biodiversity and marine related industries. Recreational vessels are recognised as an important vector of non-indigenous species translocation, particularly the secondary translocation of species domestically.\n\nThis paper reports on a novel application of multilevel modelling and multiple imputation to biomass samples gathered from the hull and other external surfaces of recreational yachts and fishing vessels in order to quantify the relationship between the wet biomass of biofouling and vessel-level characteristics. Unsurprisingly, we find that the number of days since the vessel was last cleaned was strongly related to the wet weight of biomass. The number of days since the vessel was last used was also related to the wet weight of biomass, yet differed depending on the vessel type. Similarly, the median number of trips undertaken by the vessel was related to the wet weight of biomass, and varied according to the type of antifouling paint used by the vessel. The relationship between vessel size, as measured by hull surface area, and wet weight biomass per sample unit area was not significant.\n\nIn order to reduce the international and domestic spread of invasive species, small vessel owners should use an appropriate type of antifouling paint that suits their vessels operational profile, and be encouraged to maintain a maintenance