Acute dose-response exposure of a peracetic acid-based disinfectant to Atlantic salmon parr reared in recirculating aquaculture systems

There is a high regard for peracetic acid (PAA)-based disinfectants in recirculating aquaculture systems (RAS) because of the low risk bioaccumulation, fast degradation with neutral residuals and minimal impact on biofilter performance. However, no-observed-effect concentration Atlantic salmon parr unknown. The present study evaluated effect an acute PAA exposure health welfare by evaluating survival, swimming behaviour, appetite histopathological alterations gills skin. Nine experimental RAS units were employed, where each unit was dedicated one (0.0, 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, 3.2 6.4 mg/L). Fish exposed to target static system 1 h protocol repeated after 52 recovery. fish survival 100%, 80% 0%, respectively ?1.6, mg/L. behaviour normal ? 1.6 mg/L, whereas it become erratic air gasping ? did not change among different treatment groups. Skin gill pronounced characterized poorer skin condition necrotic lamella. acidic mucous cells density 55% lower mg/L group than 0 group. sub-lethal water pH values observed administration may have played confounding compounding factor toxicity response this In conclusion, current identified be below provided insights into its use as prophylactic strategy RAS. Toxicity PAA-based influenced acidified nature, which can interfere alkalinity systems. Further studies should evaluate consequences long-term parr.