Risk assessment of hull fouling as a vector for marine non-natives in Scotland

To determine the importance of recreational boating as a vector for distributing marine organisms, including non-native species, the extent of hull fouling species on recreational yachts in Scotland was assessed. In August 2006, up to 100 yachts in each of the ten largest marinas in Scotland were ranked using a fouling index. 23 yacht owners were asked a questionnaire to determine the importance of general characteristics of the yacht and its travel history in relation to the level of hull fouling. 59 % of the yachts surveyed were found to have macrofouling attached to their hulls, suggesting that recreational boating has a high potential for distributing marine species throughout Scotland. Increased age of the antifouling paint, as well as long stationary periods and reduced sailing activity increase the risk of macrofouling species attaching to hulls. Recreational boating must be considered as a high risk vector for non-native species in Scotland.