|Liu, Dibo - Leibniz Institute Of Freshwater Ecology And Inland Fisheries|
|Pederson, Lars-flemming - Technical University Of Denmark|
|Straus, David - Dave|
|Meinelt, Thomas - Leibniz Institute Of Freshwater Ecology And Inland Fisheries|
Submitted to: International Conference on Recirculating Aquaculture
Publication Type: Abstract Only
Publication Acceptance Date: 4/29/2016
Publication Date: 8/19/2016
Citation: Liu, D., Pederson, L., Straus, D.L., Meinelt, T. 2016. Pulse vs. continuous treatment: which is better for applying peracetic acid in RAS? [abstract] 11th International Conference on Recirculating Aquaculture, August 19-21, 2016, Roanoke, Virginia. 3 p.
Technical Abstract: Peracetic acid (PAA) is a promising disinfectant in aquaculture. It is highly effective against various fish pathogens and also environmentally friendly due to harmless degradation residues. However, knowledge about potential adverse effects of PAA disinfection on fish is lacking; practical guidelines for applying PAA in recirculating aquaculture systems (RAS) requires further research. In the present study, we compared two treatment strategies for applying PAA in tanks containing rainbow trout (Oncorhynchus mykiss): pulse batch of 1 mg/L PAA (twice per week) and a continuous drip of 0.2 mg/L PAA. Biofilm was reduced by the pulse batch treatment, but enhanced by the continuous drip treatment. Fish were stressed by the first pulse batches and showed adaptation afterwards by lowering the stress response to negligible levels. In contrast, stress was not induced by the continuous drip treatment. The pulse batch treatment resulted in a larger increase of total antioxidant in serum than the continuous drip treatment. However, only the continuous drip treatment stimulated an increase of antioxidant in gill tissue. The anti-protease activity in serum was reduced by the continuous drip treatment as compared to the pulse batch treatment. Moreover, we demonstrated the importance of hydrology on the practical application of PAA with a mathematical model. In conclusion, we recommend that a pulse batch treatment of PAA, with sufficient intervals between treatments, is more manageable and less stressful for the fish and biofilter in RAS than the continuous drip treatment.