Evaluation of the properties and effectiveness of antifouling coatings in the coastal Newfoundland marine environment

Biofouling, the accumulation of organisms on submerged aquatic surfaces, can be detrimental to the aquaculture industry. In the Atlantic Canadian provinces, excluding Newfoundland and Labrador (NL), fouling by aquatic invasive tunicate species has had large economical impacts on the mussel aquaculture industry. In NL, invasive tunicates have not necessitated management, control, or removal at mussel aquaculture sites, but prevention is an important management tool. Antifouling coatings can prevent the movement of native and invasive species from a support harbour to a site. In a field study, different antifouling coatings, with different antifouling properties, (chemical and mechanical) painted on wooden panels, were submerged in coastal outports to determine the effectiveness of the coatings in the NL marine environment. A laboratory study was also conducted to determine if micro-surface topography of a coating differed amongst coatings. Coatings which contained biocides, such as Econea®, and copper and zinc, prevented biofouling accumulation for a period up to 12 months, post-deployment. Among all sites, Micron CF (Econea®) had minimal biofouling accumulation after the first year (less than 5%) and by the end of the trial had less than 60% of the area settled by fouling organisms. Foul release coatings (e.g., Hullspeed 3000) were not effective in this application. Scanning electron microscopy images showed varied textures, in structure and volume, between the different types of antifouling properties, which may promote or prevent initial settlement. All properties together are important to the efficacy of an antifouling technology. In the aquaculture industry, where vessels are not moving great distances between the docks and the farms and where operations often require vessels to move slowly to complete various work on the farm sites, the use of ecofriendly biocide antifouling coatings (e.g.,Micron CF) would be the best defense against the movement and spread of fouling organisms and aquatic invasive species