Aquaculture fouling: Efficacy of potassium monopersulphonate triple salt based disinfectant (Virkon(R) Aquatic) against Ciona intestinalis

With the increasing spread of invasive marine species and their detrimental effects on aquaculture operations globally, mitigation strategies need to be optimized to mitigate economic impacts. The efficacy of a potassium monopersulphonate triple salt based disinfectant used in the aquaculture industry (Virkon(R) Aquatic at 0.5-5%) was evaluated against the solitary tunicate Ciona intestinalis, as well as the susceptibility of three different age groups of C. intestinalis to the treatment and the effect of the disinfectant on mussel mortality. Younger C. intestinalis were most affected by all treatments, and almost all immersion applications significantly decreased the biomass of C. intestinalis compared to untreated plates. Disinfectant solutions of >/= 1% reduced biomass below pre-treatment levels. Mussel mortality was low, especially for solutions <3%. C. intestinalis should be treated 4 weeks post-settlement to maximize antifouling treatment effects. Immersion in 3% disinfectant for 30 s reduced the biomass of C. intestinalis by up to 89% and would be feasible in field applications using existing treatment equipment.