UP-SCALLING THE APPLICATION OF HYDROGEN PEROXIDE AS DESINFECTION METHOD IN A COMMERCIAL RAS REARING ATLANTIC SALMON (Salmo salar): A CASE STUDY

• Main Authors: Bögner, Desislava, Slater, Matthew James, Jähne, Gregor, Böckmann, Kyra
• Format: Conference Object
• Language: unknown
• Published: 2021
• Subjects: Atlantic salmon; Salmo salar
• Online Access: https://epic.awi.de/id/eprint/58283/; https://epic.awi.de/id/eprint/58283/1/EAS2021_DBoegner_EVONIK.pdf; https://hdl.handle.net/10013/epic.2af0f958-e3cf-40ab-95f0-67ae01df16e6

Introduction Disinfection is a very important part of recirculation aquaculture systems (RAS). RAS allows for controllable environments in which main variables relevant to animal welfare and a successful production can be manipulated as required to improve efficiency and profitability. Common disinfection methods include chemical disinfectants, antibiotics, biocides, UV radiation and ozone. They can be used to treat disease outbreaks, or to reduce the bacterial load of the system which otherwise could lead to the overgrowth of potential pathogens or opportunistic bacterial groups competing with biofilter bacteria for space and resources. Ozone is the most used disinfection method requiring expensive technology and trained stuff. Hydrogen peroxide (H2O2) has been on focus as a “green” alternative. High H2O2 doses are associated with acute toxicity symptoms for some species. Low doses are harmless, offer additional system oxygenation and contribute to water quality improvement. After testing the use of low doses in a small research RAS, the present study aims to describe the first case study up-scaling a continuous hydrogen peroxide application to commercial fish production in RAS with focus on the determination of required concentrations, application monitoring and variations on microbiome composition. Material and Methods The present study was performed at RAS facilities of Danish Salmon A/S in Hirtshals, Denmark, one of the European pioneers in rearing salmon in land based aquaculture facilities and producing about 1.200 metric tons/year of Atlantic salmon (Salmo salar). Two identical Grow-out RAS with own water treatment elements and eight pre-grow tanks were used as treatment and control systems to compare the effects of continuous H2O2 application in combination with ozone to common operational practice. Oxygen Cones and additional aeration stones ensured the basic Oxygen supply in the tanks. Defined H2O2 quantities were applied with a dosing lance connected to a peristaltic pump and an International Bulk ...