Pulse versus continuous peracetic acid applications: Effects on rainbow trout performance, biofilm formation and water quality

Abstract

a b s t r a c tPeracetic acid (PAA) products are being introduced to aquaculture as sustainable disinfectants. Two strategies are used to apply PAA: high dose pulse applications, or low dose continuous application. In the present study, their impacts on fish health and water quality were investigated in triplicate flowthrough tanks stocked with rainbow trout. The gentler and shorter water cortisol increase measured along twice-per-week pulse applications of 1 mg L −1 PAA indicated a progressive adaptation of fish. In contrast, the continuous application of 0.2 mg L −1 PAA caused no stress to fish. Meanwhile, no mortality and no impact on growth or innate cellular immunity were observed. The pulse applications restricted biofilm formation, and partially inhibited nitrification. Additionally, the highest oxygen concentration and stable pH were observed. In contrast, the continuous application promoted biofilm formation, and caused a pH increase and intermediate oxygen concentration. The contrast was probably due to different susceptibility of microbes to PAA-induced oxidative stress. To summarize, pulse PAA applications cause minor stress in fish, but have advantages over continuous application by ensuring better water quality.

Confirmation that pulse and continuous peracetic acid administration does not disrupt the acute stress response in rainbow trout

“…This strongly suggests that the decrease in the cortisol response after repeated exposure to PAA (Liu et al, 2017a(Liu et al, , 2017b) was a true process of habituation (Grissom and Bhatnagar, 2009) and was not the result of damage or disruption of the neuroendocrine cascade leading to the release of corticosteroids. This was further supported by the brain serotonergic activity.…”

“…This protocol was maintained for 6 weeks, after which the exposure experiment was completed. At that time, the average mass of the fish was 190.6 g (SD = 29.9 g) with no differences among treatment groups (Liu et al, 2017b). .…”

“…Rainbow trout utilized during the study of Liu et al (2017b) were used; their study evaluated how different types of PAA applications affected fish performance and system water quality in a flow-through aquaculture system. The applications were either repeated single dose (Pulse) or continuous via a peristaltic pump (Continuous).…”

Effect of a Peracetic Acid-Based Disinfectant on Growth, Hematology and Histology of Juvenile Rainbow Trout (Oncorhynchus mykiss)

“…In this study, no significance difference was seen in the growth factors (i.e., feed conversion ratio (FCR), specific growth rate (SGR), body weight gain (BWG) and condition factor (CF)) between treated and control fish, while the survival rate in treated fish was significantly higher than control fish. Liu et al, [18] reported that the stress induced by the PAA-based product Aqua Oxides at high concentrations depends on fish species, being the growth of rainbow trout unaffected. …”

Effect of disinfection with peracetic acid on the microbial community of a seawater aquaculture recirculation system for Pacific white shrimp (Litopenaeus vannamei)

“…In aquaculture, there are two different strategies used to apply PAA products: pulse applications, short‐term treatments using high concentrations of PAA, up to several times per day with concentrations of 1–2 mg PAA/L or continuous applications of concentrations below 0.2 mg PAA/L (Liu, Straus, Pedersen, & Meinelt, 2017). In fish aquaculture systems, it could be shown that pulse application inhibits biofilm formation in the tanks, whereas continuous application of PAA promotes biofilm formation (Liu, Straus, et al, 2017). By pulse application therefore, the amount of bacteria in the system could be reduced and stable biofilms were prevented.…”