Abstract
Biofouling is a challenge in global sea-based salmon farming. Norway's salmon-growing industry relies primarily on copper-based antifouling coatings. However, copper is an increasingly recognised environmental hazard, and there is a need to develop alternative antifouling products to prevent biofouling in marine aquaculture. Using field experiments, this study compared the efficacy of six novel antifouling coatings for fish farm nets (two with reduced copper content, three with alternative biocides and one biocide-free coating) against a popular commercial copper coating and uncoated samples. The performance of one of the new coatings with lower copper content was more similar to the commercial copper control while the rest were colonised by biofouling faster and/or at higher abundances. However, none of the tested products were able to prevent biofouling entirely, underlining the importance of the search for alternative and improved antifouling technologies.