Deciphering the composition and transformation of dissolved organic matter in recirculating aquaculture systems by high-resolution mass spectrometry

Abstract

The continuous increase in the human population is prompting the need for aquaculture systems able to sustain the global demand for fish without affecting the environment. Recirculating aquaculture systems (RAS) are a new alternative to traditional aquaculture systems managing the water quality to create optimal conditions for fish growth. In these systems, the water input from natural sources is recycled through different mechanisms and treated to control biological pollution, hygiene and diseases. The implementation of these systems has not been widely approved due to one of its several limitations: accumulation of dissolved organic matter (DOM). The DOM accumulated in the system have different origins and can have potential effects on water quality, fish welfare and system performance. Thus, the characterization of the compounds contained in DOM has become the primary objective in RAS to improve water quality and consequently fish productivity. The focus of this thesis was to apply non-targeted analyses using high-resolution mass spectrometry techniques (HRMS) to decipher for the first time the molecular composition of DOM in RAS with Atlantic Salmon (Salmo salar) and its transformation during the water treatment processes of RAS. The work presented in this thesis adds a new chapter to understanding the water quality of RAS.