The European research project RASbiome: Microbial management in RAS for sustainable aquaculture production, funded by ERA-NET BlueBio, aims to improve the sustainability of fish production in recirculating aquaculture systems (RAS) by introducing new and innovative approaches for microbiological water treatment.
BioMar is contributing to the research project and Pedro Gómez Requeni, senior scientist at the Nutrition Formulation Department of BioMar Global R&D, is leading BioMar’s R&D area working on the development of RAS feeds. “It is BioMar’s ambition to contribute to solving important challenges in RAS farming. BioMar welcomes investing R&D efforts in research projects on how to improve RAS production, i.e. by lowering energy consumption and carbon footprint, and on how to alleviate sludge removal,” Gómez Requeni said.
The RASbiome project will focus on implementing two fundamentally distinct biological water treatment strategies, new to RAS, to improve the management of nitrogen compounds.
The first strategy involves anaerobic ammonia-oxidizing (anammox) bacteria, resulting in almost complete removal of nitrogen from the water. This strategy excludes the need for external organic carbon, it entails reduced energy consumption and reduced CO2 production.
The second strategy takes advantage of biofloc formed by heterotrophic bacteria, assimilating nitrogen. This approach allows for harvesting sludge consisting of nutrient-rich microbial biomass. Therefore, it is compatible with the recovery and recycling of nitrogen from RAS water streams.
The project is highly multidisciplinary, involving experts from Belgium, Denmark and Norway in fields of environmental engineering, biotechnology, microbiology, microbial ecology and aquaculture. Industry partners, including two large commercial producers of salmon smolt and rainbow trout, play a crucial role in the project. BioMar participates in the RASbiome project by providing the feeds for biological trials on rainbow trout juveniles run by DTU Aqua. The different diets in the trials will be varying carbon-to-nitrogen ratios, an essential parameter for microorganism performance.
The expected sustainability outcomes of this project for aquaculture production are improving fish welfare and productivity due to stable and optimized chemical and microbiological water quality, reducing environmental impact through nitrogen removal from discharged water and reducing operational costs.
“BioMar, as well as all RASbiome project partners, truly expect the proposed project to give innovative outcomes on key challenges. New measures that can be applied in microbial water treatment, and especially in the management of nitrogen compounds, will undoubtedly promote sustainable fish production in freshwater RAS systems,” concluded Gómez Requeni.