The effectiveness of several commercial antifouling treatments at reducing biofouling on finfish aquaculture cages in British Columbia

Biofouling in finfish aquaculture is an important issue because copper based antifoulants contribute to marine pollution and biofouling management incurs heavy costs to the industry. The purpose of this study was to assess the effectiveness five treatments (non‐biocidal: Dyneema, Netpolish, Aquacoating and ThornD; biocidal using cuprous oxide: Netrex) as compared with an untreated nylon net. After 8 months, effectiveness was determined by quantifying changes in: per cent net occlusion, per cent cover of major fouling groups, and biomass. Only one non‐biocidal treatment performed better than the control in one performance index (Dyneema had lower biomass), and overall, the copper treatment was most effective. The results from this study demonstrated that the effectiveness of copper treatments will continue to be a barrier to the implementation of non‐biocidal antifoulants, and that more research is needed to develop effective, non‐biocidal antifoulant coatings for aquaculture operations.